/* * Copyright 2015-2017 Leonid Yuriev . * * This code is derived from "LMDB engine" written by * Howard Chu (Symas Corporation), which itself derived from btree.c * written by Martin Hedenfalk. * * --- * * Portions Copyright 2011-2017 Howard Chu, Symas Corp. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted only as authorized by the OpenLDAP * Public License. * * A copy of this license is available in the file LICENSE in the * top-level directory of the distribution or, alternatively, at * . * * --- * * Portions Copyright (c) 2009, 2010 Martin Hedenfalk * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif #include #include "mdbx.h" #ifndef MDB_DEBUG #define MDB_DEBUG 0 #endif /* LY: Please do not ask us for Windows support, just never! * But you can make a fork for Windows, or become maintainer for FreeBSD... */ #ifndef __gnu_linux__ #warning "libmdbx supports only GNU Linux" #endif #if !defined(__GNUC__) || !__GNUC_PREREQ(4, 2) /* LY: Actualy libmdbx was not tested with compilers * older than GCC 4.4 (from RHEL6). * But you could remove this #error and try to continue at your own risk. * In such case please don't rise up an issues related ONLY to old compilers. */ #warning "libmdbx required at least GCC 4.2 compatible C/C++ compiler." #endif #if !defined(__GNU_LIBRARY__) || !__GLIBC_PREREQ(2, 12) /* LY: Actualy libmdbx was not tested with something * older than glibc 2.12 (from RHEL6). * But you could remove this #error and try to continue at your own risk. * In such case please don't rise up an issues related ONLY to old systems. */ #warning "libmdbx required at least GLIBC 2.12." #endif #if MDB_DEBUG #undef NDEBUG #endif #include #include #include #include #include #ifdef HAVE_SYS_FILE_H #include #endif #include #include #include #include #include #include #include #include #include #include #include #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER)) #include #include /* defines BYTE_ORDER on HPUX and Solaris */ #endif #ifndef _POSIX_SYNCHRONIZED_IO #define fdatasync fsync #endif #ifndef BYTE_ORDER #if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && \ !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)) /* Solaris just defines one or the other */ #define LITTLE_ENDIAN 1234 #define BIG_ENDIAN 4321 #ifdef _LITTLE_ENDIAN #define BYTE_ORDER LITTLE_ENDIAN #else #define BYTE_ORDER BIG_ENDIAN #endif #else #define BYTE_ORDER __BYTE_ORDER #endif #endif #ifndef LITTLE_ENDIAN #define LITTLE_ENDIAN __LITTLE_ENDIAN #endif #ifndef BIG_ENDIAN #define BIG_ENDIAN __BIG_ENDIAN #endif #if defined(__i386) || defined(__x86_64) || defined(_M_IX86) #define MISALIGNED_OK 1 #endif #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN) #error "Unknown or unsupported endianness (BYTE_ORDER)" #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF #error "Two's complement, reasonably sized integer types, please" #endif #include "./barriers.h" #include "./midl.h" #include "./reopen.h" /** Search for an ID in an IDL. * @param[in] ids The IDL to search. * @param[in] id The ID to search for. * @return The index of the first ID greater than or equal to \b id. */ static unsigned mdbx_midl_search(MDB_IDL ids, MDB_ID id); /** Allocate an IDL. * Allocates memory for an IDL of the given size. * @return IDL on success, NULL on failure. */ static MDB_IDL mdbx_midl_alloc(int num); /** Free an IDL. * @param[in] ids The IDL to free. */ static void mdbx_midl_free(MDB_IDL ids); /** Shrink an IDL. * Return the IDL to the default size if it has grown larger. * @param[in,out] idp Address of the IDL to shrink. */ static void mdbx_midl_shrink(MDB_IDL *idp); /** Make room for num additional elements in an IDL. * @param[in,out] idp Address of the IDL. * @param[in] num Number of elements to make room for. * @return 0 on success, ENOMEM on failure. */ static int mdbx_midl_need(MDB_IDL *idp, unsigned num); /** Append an ID onto an IDL. * @param[in,out] idp Address of the IDL to append to. * @param[in] id The ID to append. * @return 0 on success, ENOMEM if the IDL is too large. */ static int mdbx_midl_append(MDB_IDL *idp, MDB_ID id); /** Append an IDL onto an IDL. * @param[in,out] idp Address of the IDL to append to. * @param[in] app The IDL to append. * @return 0 on success, ENOMEM if the IDL is too large. */ static int mdbx_midl_append_list(MDB_IDL *idp, MDB_IDL app); /** Append an ID range onto an IDL. * @param[in,out] idp Address of the IDL to append to. * @param[in] id The lowest ID to append. * @param[in] n Number of IDs to append. * @return 0 on success, ENOMEM if the IDL is too large. */ static int mdbx_midl_append_range(MDB_IDL *idp, MDB_ID id, unsigned n); /** Merge an IDL onto an IDL. The destination IDL must be big enough. * @param[in] idl The IDL to merge into. * @param[in] merge The IDL to merge. */ static void mdbx_midl_xmerge(MDB_IDL idl, MDB_IDL merge); /** Sort an IDL. * @param[in,out] ids The IDL to sort. */ static void mdbx_midl_sort(MDB_IDL ids); /** Search for an ID in an ID2L. * @param[in] ids The ID2L to search. * @param[in] id The ID to search for. * @return The index of the first ID2 whose \b mid member is greater than * or equal to \b id. */ static unsigned mdbx_mid2l_search(MDB_ID2L ids, MDB_ID id); /** Insert an ID2 into a ID2L. * @param[in,out] ids The ID2L to insert into. * @param[in] id The ID2 to insert. * @return 0 on success, -1 if the ID was already present in the ID2L. */ static int mdbx_mid2l_insert(MDB_ID2L ids, MDB_ID2 *id); /** Append an ID2 into a ID2L. * @param[in,out] ids The ID2L to append into. * @param[in] id The ID2 to append. * @return 0 on success, -2 if the ID2L is too big. */ static int mdbx_mid2l_append(MDB_ID2L ids, MDB_ID2 *id); int mdbx_runtime_flags = MDBX_DBG_PRINT #if MDB_DEBUG | MDBX_DBG_ASSERT #endif #if MDB_DEBUG > 1 | MDBX_DBG_TRACE #endif #if MDB_DEBUG > 2 | MDBX_DBG_AUDIT #endif #if MDB_DEBUG > 3 | MDBX_DBG_EXTRA #endif ; static MDBX_debug_func *mdbx_debug_logger; int mdbx_setup_debug(int flags, MDBX_debug_func *logger, long edge_txn); /** Features under development */ #ifndef MDB_DEVEL #define MDB_DEVEL 0 #endif /** Wrapper around __func__, which is a C99 feature */ #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L #define mdbx_func_ __func__ #elif (defined(__GNUC__) && __GNUC__ >= 2) || defined(__clang__) #define mdbx_func_ __FUNCTION__ #else /* If a debug message says (), update the #if statements above */ #define mdbx_func_ "" #endif /** Some platforms define the EOWNERDEAD error code * even though they don't support Robust Mutexes. * Compile with -DMDB_USE_ROBUST=0. */ #ifndef MDB_USE_ROBUST /* Howard Chu: Android currently lacks Robust Mutex support */ #if defined(EOWNERDEAD) && \ !defined(ANDROID) /* LY: glibc before 2.10 has a troubles with Robust \ Mutex too. */ \ && __GLIBC_PREREQ(2, 10) #define MDB_USE_ROBUST 1 #else #define MDB_USE_ROBUST 0 #endif #endif /* MDB_USE_ROBUST */ /* Internal error codes, not exposed outside liblmdb */ #define MDB_NO_ROOT (MDB_LAST_ERRCODE + 10) /** Mutex for the reader table (rw = r) or write transaction (rw = w). */ #define MDB_MUTEX(env, rw) (&(env)->me_txns->mti_##rw##mutex) /** An abstraction for a file handle. * On POSIX systems file handles are small integers. On Windows * they're opaque pointers. */ #define HANDLE int /** A value for an invalid file handle. * Mainly used to initialize file variables and signify that they are * unused. */ #define INVALID_HANDLE_VALUE (-1) /** Get the size of a memory page for the system. * This is the basic size that the platform's memory manager uses, and is * fundamental to the use of memory-mapped files. */ #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE)) /** @} */ static int mdbx_mutex_lock(MDB_env *env, pthread_mutex_t *mutex); static int mdbx_mutex_failed(MDB_env *env, pthread_mutex_t *mutex, int rc); static void mdbx_mutex_unlock(MDB_env *env, pthread_mutex_t *mutex); /** A page number in the database. * Note that 64 bit page numbers are overkill, since pages themselves * already represent 12-13 bits of addressable memory, and the OS will * always limit applications to a maximum of 63 bits of address space. * * @note In the #MDB_node structure, we only store 48 bits of this value, * which thus limits us to only 60 bits of addressable data. */ typedef MDB_ID pgno_t; /** A transaction ID. * See struct MDB_txn.mt_txnid for details. */ typedef MDB_ID txnid_t; /** @defgroup debug Debug Macros * @{ */ /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */ #define DDBI(mc) \ (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi) /** @} */ /** @brief The maximum size of a database page. * * It is 32k or 64k, since value-PAGEBASE must fit in * #MDB_page.%mp_upper. * * LMDB will use database pages < OS pages if needed. * That causes more I/O in write transactions: The OS must * know (read) the whole page before writing a partial page. * * Note that we don't currently support Huge pages. On Linux, * regular data files cannot use Huge pages, and in general * Huge pages aren't actually pageable. We rely on the OS * demand-pager to read our data and page it out when memory * pressure from other processes is high. So until OSs have * actual paging support for Huge pages, they're not viable. */ #define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000) /** The minimum number of keys required in a database page. * Setting this to a larger value will place a smaller bound on the * maximum size of a data item. Data items larger than this size will * be pushed into overflow pages instead of being stored directly in * the B-tree node. This value used to default to 4. With a page size * of 4096 bytes that meant that any item larger than 1024 bytes would * go into an overflow page. That also meant that on average 2-3KB of * each overflow page was wasted space. The value cannot be lower than * 2 because then there would no longer be a tree structure. With this * value, items larger than 2KB will go into overflow pages, and on * average only 1KB will be wasted. */ #define MDB_MINKEYS 2 /** A stamp that identifies a file as an LMDB file. * There's nothing special about this value other than that it is easily * recognizable, and it will reflect any byte order mismatches. */ #define MDB_MAGIC 0xBEEFC0DE /** The version number for a database's datafile format. */ #define MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1) /** The version number for a database's lockfile format. */ #define MDB_LOCK_VERSION ((MDB_DEVEL) ? 999 : 1) /** @brief The max size of a key we can write, or 0 for computed max. * * This macro should normally be left alone or set to 0. * Note that a database with big keys or dupsort data cannot be * reliably modified by a liblmdb which uses a smaller max. * The default is 511 for backwards compat, or 0 when #MDB_DEVEL. * * Other values are allowed, for backwards compat. However: * A value bigger than the computed max can break if you do not * know what you are doing, and liblmdb <= 0.9.10 can break when * modifying a DB with keys/dupsort data bigger than its max. * * Data items in an #MDB_DUPSORT database are also limited to * this size, since they're actually keys of a sub-DB. Keys and * #MDB_DUPSORT data items must fit on a node in a regular page. */ #ifndef MDB_MAXKEYSIZE #define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511) #endif /** The maximum size of a key we can write to the environment. */ #if MDB_MAXKEYSIZE #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE) #else #define ENV_MAXKEY(env) ((env)->me_maxkey_limit) #endif /* MDB_MAXKEYSIZE */ /** @brief The maximum size of a data item. * * We only store a 32 bit value for node sizes. */ #define MAXDATASIZE 0xffffffffUL /** Key size which fits in a #DKBUF. * @ingroup debug */ #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511) /** A key buffer. * @ingroup debug * This is used for printing a hex dump of a key's contents. */ #define DKBUF char kbuf[DKBUF_MAXKEYSIZE * 2 + 1] /** Display a key in hex. * @ingroup debug * Invoke a function to display a key in hex. */ #define DKEY(x) mdbx_dkey(x, kbuf) /** An invalid page number. * Mainly used to denote an empty tree. */ #define P_INVALID (~(pgno_t)0) /** Test if the flags \b f are set in a flag word \b w. */ #define F_ISSET(w, f) (((w) & (f)) == (f)) /** Round \b n up to an even number. */ #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */ /** Used for offsets within a single page. * Since memory pages are typically 4 or 8KB in size, 12-13 bits, * this is plenty. */ typedef uint16_t indx_t; /** Default size of memory map. * This is certainly too small for any actual applications. Apps should *always set * the size explicitly using #mdbx_env_set_mapsize(). */ #define DEFAULT_MAPSIZE 1048576 /** @defgroup readers Reader Lock Table * Readers don't acquire any locks for their data access. Instead, they * simply record their transaction ID in the reader table. The reader * mutex is needed just to find an empty slot in the reader table. The * slot's address is saved in thread-specific data so that subsequent *read * transactions started by the same thread need no further locking to *proceed. * * If #MDB_NOTLS is set, the slot address is not saved in thread-specific *data. * * No reader table is used if the database is on a read-only filesystem, *or * if #MDB_NOLOCK is set. * * Since the database uses multi-version concurrency control, readers *don't * actually need any locking. This table is used to keep track of which * readers are using data from which old transactions, so that we'll know * when a particular old transaction is no longer in use. Old *transactions * that have discarded any data pages can then have those pages reclaimed * for use by a later write transaction. * * The lock table is constructed such that reader slots are aligned with *the * processor's cache line size. Any slot is only ever used by one thread. * This alignment guarantees that there will be no contention or cache * thrashing as threads update their own slot info, and also eliminates * any need for locking when accessing a slot. * * A writer thread will scan every slot in the table to determine the *oldest * outstanding reader transaction. Any freed pages older than this will *be * reclaimed by the writer. The writer doesn't use any locks when *scanning * this table. This means that there's no guarantee that the writer will * see the most up-to-date reader info, but that's not required for *correct * operation - all we need is to know the upper bound on the oldest *reader, * we don't care at all about the newest reader. So the only consequence *of * reading stale information here is that old pages might hang around a * while longer before being reclaimed. That's actually good anyway, *because * the longer we delay reclaiming old pages, the more likely it is that a * string of contiguous pages can be found after coalescing old pages *from * many old transactions together. * @{ */ /** Number of slots in the reader table. * This value was chosen somewhat arbitrarily. 126 readers plus a * couple mutexes fit exactly into 8KB on my development machine. * Applications should set the table size using *#mdbx_env_set_maxreaders(). */ #define DEFAULT_READERS 126 /** The information we store in a single slot of the reader table. * In addition to a transaction ID, we also record the process and * thread ID that owns a slot, so that we can detect stale information, * e.g. threads or processes that went away without cleaning up. * @note We currently don't check for stale records. We simply re-init * the table when we know that we're the only process opening the * lock file. */ typedef struct MDB_rxbody { /** Current Transaction ID when this transaction began, or (txnid_t)-1. * Multiple readers that start at the same time will probably have the * same ID here. Again, it's not important to exclude them from * anything; all we need to know is which version of the DB they * started from so we can avoid overwriting any data used in that * particular version. */ volatile txnid_t mrb_txnid; /** The process ID of the process owning this reader txn. */ volatile pid_t mrb_pid; /** The thread ID of the thread owning this txn. */ volatile pthread_t mrb_tid; } MDB_rxbody; /** The actual reader record, with cacheline padding. */ typedef struct MDB_reader { union { MDB_rxbody mrx; /** shorthand for mrb_txnid */ #define mr_txnid mru.mrx.mrb_txnid #define mr_pid mru.mrx.mrb_pid #define mr_tid mru.mrx.mrb_tid /** cache line alignment */ char pad[(sizeof(MDB_rxbody) + CACHELINE_SIZE - 1) & ~(CACHELINE_SIZE - 1)]; } mru; } MDB_reader; /** The header for the reader table. * The table resides in a memory-mapped file. (This is a different file * than is used for the main database.) * * For POSIX the actual mutexes reside in the shared memory of this * mapped file. On Windows, mutexes are named objects allocated by the * kernel; we store the mutex names in this mapped file so that other * processes can grab them. This same approach is also used on * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support * process-shared POSIX mutexes. For these cases where a named object * is used, the object name is derived from a 64 bit FNV hash of the * environment pathname. As such, naming collisions are extremely * unlikely. If a collision occurs, the results are unpredictable. */ typedef struct MDB_txbody { /** Stamp identifying this as an LMDB file. It must be set * to #MDB_MAGIC. */ uint32_t mtb_magic; /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */ uint32_t mtb_format; /** Mutex protecting access to this table. * This is the #MDB_MUTEX(env,r) reader table lock. */ pthread_mutex_t mtb_rmutex; /** The ID of the last transaction committed to the database. * This is recorded here only for convenience; the value can always * be determined by reading the main database meta pages. */ volatile txnid_t mtb_txnid; /** The number of slots that have been used in the reader table. * This always records the maximum count, it is not decremented * when readers release their slots. */ volatile unsigned mtb_numreaders; } MDB_txbody; /** The actual reader table definition. */ typedef struct MDB_txninfo { union { MDB_txbody mtb; #define mti_magic mt1.mtb.mtb_magic #define mti_format mt1.mtb.mtb_format #define mti_rmutex mt1.mtb.mtb_rmutex #define mti_rmname mt1.mtb.mtb_rmname #define mti_txnid mt1.mtb.mtb_txnid #define mti_numreaders mt1.mtb.mtb_numreaders char pad[(sizeof(MDB_txbody) + CACHELINE_SIZE - 1) & ~(CACHELINE_SIZE - 1)]; } mt1; union { pthread_mutex_t mt2_wmutex; #define mti_wmutex mt2.mt2_wmutex char pad[(sizeof(pthread_mutex_t) + CACHELINE_SIZE - 1) & ~(CACHELINE_SIZE - 1)]; } mt2; MDB_reader mti_readers[1]; } MDB_txninfo; /** Lockfile format signature: version, features and field layout */ #define MDB_LOCK_FORMAT \ ((uint32_t)((MDB_LOCK_VERSION) /* Flags which describe functionality */ \ + (0 /* SYSV_SEM_FLAG */ << 18) + (1 /* MDB_PIDLOCK */ << 16))) /** @} */ /** Common header for all page types. The page type depends on #mp_flags. * * #P_BRANCH and #P_LEAF pages have unsorted '#MDB_node's at the end, with * sorted #mp_ptrs[] entries referring to them. Exception: #P_LEAF2 pages * omit mp_ptrs and pack sorted #MDB_DUPFIXED values after the page header. * * #P_OVERFLOW records occupy one or more contiguous pages where only the * first has a page header. They hold the real data of #F_BIGDATA nodes. * * #P_SUBP sub-pages are small leaf "pages" with duplicate data. * A node with flag #F_DUPDATA but not #F_SUBDATA contains a sub-page. * (Duplicate data can also go in sub-databases, which use normal pages.) * * #P_META pages contain #MDB_meta, the start point of an LMDB snapshot. * * Each non-metapage up to #MDB_meta.%mm_last_pg is reachable exactly once * in the snapshot: Either used by a database or listed in a freeDB record. */ typedef struct MDB_page { #define mp_pgno mp_p.p_pgno #define mp_next mp_p.p_next union { pgno_t p_pgno; /**< page number */ struct MDB_page *p_next; /**< for in-memory list of freed pages */ } mp_p; uint16_t mp_leaf2_ksize; /**< key size if this is a LEAF2 page */ /** @defgroup mdbx_page Page Flags * @ingroup internal * Flags for the page headers. * @{ */ #define P_BRANCH 0x01 /**< branch page */ #define P_LEAF 0x02 /**< leaf page */ #define P_OVERFLOW 0x04 /**< overflow page */ #define P_META 0x08 /**< meta page */ #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */ #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */ #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */ #define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */ #define P_KEEP 0x8000 /**< leave this page alone during spill */ /** @} */ uint16_t mp_flags; /**< @ref mdbx_page */ #define mp_lower mp_pb.pb.pb_lower #define mp_upper mp_pb.pb.pb_upper #define mp_pages mp_pb.pb_pages union { struct { indx_t pb_lower; /**< lower bound of free space */ indx_t pb_upper; /**< upper bound of free space */ } pb; uint32_t pb_pages; /**< number of overflow pages */ } mp_pb; indx_t mp_ptrs[1]; /**< dynamic size */ } MDB_page; /** Size of the page header, excluding dynamic data at the end */ #define PAGEHDRSZ ((unsigned)offsetof(MDB_page, mp_ptrs)) /** Address of first usable data byte in a page, after the header */ #define PAGEDATA(p) ((void *)((char *)(p) + PAGEHDRSZ)) /** ITS#7713, change PAGEBASE to handle 65536 byte pages */ #define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0) /** Number of nodes on a page */ #define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ - PAGEBASE)) >> 1) /** The amount of space remaining in the page */ #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower) /** The percentage of space used in the page, in tenths of a percent. */ #define PAGEFILL(env, p) \ (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \ ((env)->me_psize - PAGEHDRSZ)) /** The minimum page fill factor, in tenths of a percent. * Pages emptier than this are candidates for merging. */ #define FILL_THRESHOLD 250 /** Test if a page is a leaf page */ #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF) /** Test if a page is a LEAF2 page */ #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2) /** Test if a page is a branch page */ #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH) /** Test if a page is an overflow page */ #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW) /** Test if a page is a sub page */ #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP) /** The number of overflow pages needed to store the given size. */ #define OVPAGES(size, psize) ((PAGEHDRSZ - 1 + (size)) / (psize) + 1) /** Link in #MDB_txn.%mt_loose_pgs list. * Kept outside the page header, which is needed when reusing the page. */ #define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2)) /** Header for a single key/data pair within a page. * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2. * We guarantee 2-byte alignment for 'MDB_node's. * * #mn_lo and #mn_hi are used for data size on leaf nodes, and for child * pgno on branch nodes. On 64 bit platforms, #mn_flags is also used * for pgno. (Branch nodes have no flags). Lo and hi are in host byte * order in case some accesses can be optimized to 32-bit word access. * * Leaf node flags describe node contents. #F_BIGDATA says the node's * data part is the page number of an overflow page with actual data. * #F_DUPDATA and #F_SUBDATA can be combined giving duplicate data in * a sub-page/sub-database, and named databases (just #F_SUBDATA). */ typedef struct MDB_node { /** part of data size or pgno * @{ */ #if BYTE_ORDER == LITTLE_ENDIAN unsigned short mn_lo, mn_hi; #else unsigned short mn_hi, mn_lo; #endif /** @} */ /** @defgroup mdbx_node Node Flags * @ingroup internal * Flags for node headers. * @{ */ #define F_BIGDATA 0x01 /**< data put on overflow page */ #define F_SUBDATA 0x02 /**< data is a sub-database */ #define F_DUPDATA 0x04 /**< data has duplicates */ /** valid flags for #mdbx_node_add() */ #define NODE_ADD_FLAGS (F_DUPDATA | F_SUBDATA | MDB_RESERVE | MDB_APPEND) /** @} */ unsigned short mn_flags; /**< @ref mdbx_node */ unsigned short mn_ksize; /**< key size */ char mn_data[1]; /**< key and data are appended here */ } MDB_node; /** Size of the node header, excluding dynamic data at the end */ #define NODESIZE offsetof(MDB_node, mn_data) /** Bit position of top word in page number, for shifting mn_flags */ #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0) /** Size of a node in a branch page with a given key. * This is just the node header plus the key, there is no data. */ #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size)) /** Size of a node in a leaf page with a given key and data. * This is node header plus key plus data size. */ #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size) /** Address of node \b i in page \b p */ #define NODEPTR(p, i) \ ({ \ assert(NUMKEYS(p) > (unsigned)(i)); \ (MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE); \ }) /** Address of the key for the node */ #define NODEKEY(node) (void *)((node)->mn_data) /** Address of the data for a node */ #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize) /** Get the page number pointed to by a branch node */ #define NODEPGNO(node) \ ((node)->mn_lo | ((pgno_t)(node)->mn_hi << 16) | \ (PGNO_TOPWORD ? ((pgno_t)(node)->mn_flags << PGNO_TOPWORD) : 0)) /** Set the page number in a branch node */ #define SETPGNO(node, pgno) \ do { \ (node)->mn_lo = (pgno)&0xffff; \ (node)->mn_hi = (pgno) >> 16; \ if (PGNO_TOPWORD) \ (node)->mn_flags = (pgno) >> PGNO_TOPWORD; \ } while (0) /** Get the size of the data in a leaf node */ #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16)) /** Set the size of the data for a leaf node */ #define SETDSZ(node, size) \ do { \ (node)->mn_lo = (size)&0xffff; \ (node)->mn_hi = (size) >> 16; \ } while (0) /** The size of a key in a node */ #define NODEKSZ(node) ((node)->mn_ksize) /** Copy a page number from src to dst */ #ifdef MISALIGNED_OK #define COPY_PGNO(dst, src) dst = src #elif SIZE_MAX > 4294967295UL #define COPY_PGNO(dst, src) \ do { \ unsigned short *s, *d; \ s = (unsigned short *)&(src); \ d = (unsigned short *)&(dst); \ *d++ = *s++; \ *d++ = *s++; \ *d++ = *s++; \ *d = *s; \ } while (0) #else #define COPY_PGNO(dst, src) \ do { \ unsigned short *s, *d; \ s = (unsigned short *)&(src); \ d = (unsigned short *)&(dst); \ *d++ = *s++; \ *d = *s; \ } while (0) #endif /* MISALIGNED_OK */ /** The address of a key in a LEAF2 page. * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate *sub-DBs. * There are no node headers, keys are stored contiguously. */ #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i) * (ks))) /** Set the \b node's key into \b keyptr, if requested. */ #define MDB_GET_KEY(node, keyptr) \ { \ if ((keyptr) != NULL) { \ (keyptr)->mv_size = NODEKSZ(node); \ (keyptr)->mv_data = NODEKEY(node); \ } \ } /** Set the \b node's key into \b key. */ #define MDB_GET_KEY2(node, key) \ { \ key.mv_size = NODEKSZ(node); \ key.mv_data = NODEKEY(node); \ } /** Information about a single database in the environment. */ typedef struct MDB_db { uint32_t md_xsize; /**< also ksize for LEAF2 pages */ uint16_t md_flags; /**< @ref mdbx_dbi_open */ uint16_t md_depth; /**< depth of this tree */ pgno_t md_branch_pages; /**< number of internal pages */ pgno_t md_leaf_pages; /**< number of leaf pages */ pgno_t md_overflow_pages; /**< number of overflow pages */ size_t md_entries; /**< number of data items */ pgno_t md_root; /**< the root page of this tree */ } MDB_db; #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */ #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID)) /** #mdbx_dbi_open() flags */ #define VALID_FLAGS \ (MDB_REVERSEKEY | MDB_DUPSORT | MDB_INTEGERKEY | MDB_DUPFIXED | \ MDB_INTEGERDUP | MDB_REVERSEDUP | MDB_CREATE) /** Handle for the DB used to track free pages. */ #define FREE_DBI 0 /** Handle for the default DB. */ #define MAIN_DBI 1 /** Number of DBs in metapage (free and main) - also hardcoded elsewhere */ #define CORE_DBS 2 /** Number of meta pages - also hardcoded elsewhere */ #define NUM_METAS 2 /** Meta page content. * A meta page is the start point for accessing a database snapshot. * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2). */ typedef struct MDB_meta { /** Stamp identifying this as an LMDB file. It must be set * to #MDB_MAGIC. */ uint32_t mm_magic; /** Version number of this file. Must be set to #MDB_DATA_VERSION. */ uint32_t mm_version; void *mm_address; /**< address for fixed mapping */ size_t mm_mapsize; /**< size of mmap region */ MDB_db mm_dbs[CORE_DBS]; /**< first is free space, 2nd is main db */ /** The size of pages used in this DB */ #define mm_psize mm_dbs[FREE_DBI].md_xsize /** Any persistent environment flags. @ref mdbx_env */ #define mm_flags mm_dbs[FREE_DBI].md_flags /** Last used page in the datafile. * Actually the file may be shorter if the freeDB lists the final pages. */ pgno_t mm_last_pg; volatile txnid_t mm_txnid; /**< txnid that committed this page */ #define MDB_DATASIGN_NONE 0 #define MDB_DATASIGN_WEAK 1 volatile uint64_t mm_datasync_sign; #define META_IS_WEAK(meta) ((meta)->mm_datasync_sign == MDB_DATASIGN_WEAK) #define META_IS_STEADY(meta) ((meta)->mm_datasync_sign > MDB_DATASIGN_WEAK) #if MDBX_MODE_ENABLED volatile mdbx_canary mm_canary; #endif } MDB_meta; /** Buffer for a stack-allocated meta page. * The members define size and alignment, and silence type * aliasing warnings. They are not used directly; that could * mean incorrectly using several union members in parallel. */ typedef union MDB_metabuf { MDB_page mb_page; struct { char mm_pad[PAGEHDRSZ]; MDB_meta mm_meta; } mb_metabuf; } MDB_metabuf; /** Auxiliary DB info. * The information here is mostly static/read-only. There is * only a single copy of this record in the environment. */ typedef struct MDB_dbx { MDB_val md_name; /**< name of the database */ MDB_cmp_func *md_cmp; /**< function for comparing keys */ MDB_cmp_func *md_dcmp; /**< function for comparing data items */ } MDB_dbx; #if MDBX_MODE_ENABLED #define MDBX_MODE_SALT 0 #else #error !? #endif /** A database transaction. * Every operation requires a transaction handle. */ struct MDB_txn { #define MDBX_MT_SIGNATURE (0x93D53A31 ^ MDBX_MODE_SALT) unsigned mt_signature; MDB_txn *mt_parent; /**< parent of a nested txn */ /** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */ MDB_txn *mt_child; pgno_t mt_next_pgno; /**< next unallocated page */ /** The ID of this transaction. IDs are integers incrementing from 1. * Only committed write transactions increment the ID. If a transaction * aborts, the ID may be re-used by the next writer. */ txnid_t mt_txnid; MDB_env *mt_env; /**< the DB environment */ /** The list of reclaimed txns from freeDB */ MDB_IDL mt_lifo_reclaimed; /** The list of pages that became unused during this transaction. */ MDB_IDL mt_free_pgs; /** The list of loose pages that became unused and may be reused * in this transaction, linked through #NEXT_LOOSE_PAGE(page). */ MDB_page *mt_loose_pgs; /** Number of loose pages (#mt_loose_pgs) */ int mt_loose_count; /** The sorted list of dirty pages we temporarily wrote to disk * because the dirty list was full. page numbers in here are * shifted left by 1, deleted slots have the LSB set. */ MDB_IDL mt_spill_pgs; union { /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */ MDB_ID2L dirty_list; /** For read txns: This thread/txn's reader table slot, or NULL. */ MDB_reader *reader; } mt_u; /** Array of records for each DB known in the environment. */ MDB_dbx *mt_dbxs; /** Array of MDB_db records for each known DB */ MDB_db *mt_dbs; /** Array of sequence numbers for each DB handle */ unsigned *mt_dbiseqs; /** @defgroup mt_dbflag Transaction DB Flags * @ingroup internal * @{ */ #define DB_DIRTY 0x01 /**< DB was written in this txn */ #define DB_STALE 0x02 /**< Named-DB record is older than txnID */ #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */ #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */ #define DB_USRVALID 0x10 /**< As #DB_VALID, but not set for #FREE_DBI */ #define DB_DUPDATA 0x20 /**< DB is #MDB_DUPSORT data */ /** @} */ /** In write txns, array of cursors for each DB */ MDB_cursor **mt_cursors; /** Array of flags for each DB */ unsigned char *mt_dbflags; /** Number of DB records in use, or 0 when the txn is finished. * This number only ever increments until the txn finishes; we * don't decrement it when individual DB handles are closed. */ MDB_dbi mt_numdbs; /** @defgroup mdbx_txn Transaction Flags * @ingroup internal * @{ */ /** #mdbx_txn_begin() flags */ #define MDB_TXN_BEGIN_FLAGS (MDB_NOMETASYNC | MDB_NOSYNC | MDB_RDONLY) #define MDB_TXN_NOMETASYNC \ MDB_NOMETASYNC /**< don't sync meta for this txn on commit */ #define MDB_TXN_NOSYNC MDB_NOSYNC /**< don't sync this txn on commit */ #define MDB_TXN_RDONLY MDB_RDONLY /**< read-only transaction */ /* internal txn flags */ #define MDB_TXN_WRITEMAP \ MDB_WRITEMAP /**< copy of #MDB_env flag in writers \ */ #define MDB_TXN_FINISHED 0x01 /**< txn is finished or never began */ #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */ #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */ #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */ #define MDB_TXN_HAS_CHILD 0x10 /**< txn has an #MDB_txn.%mt_child */ /** most operations on the txn are currently illegal */ #define MDB_TXN_BLOCKED (MDB_TXN_FINISHED | MDB_TXN_ERROR | MDB_TXN_HAS_CHILD) /** @} */ unsigned mt_flags; /**< @ref mdbx_txn */ /** #dirty_list room: Array size - \#dirty pages visible to this txn. * Includes ancestor txns' dirty pages not hidden by other txns' * dirty/spilled pages. Thus commit(nested txn) has room to merge * dirty_list into mt_parent after freeing hidden mt_parent pages. */ unsigned mt_dirty_room; #if MDBX_MODE_ENABLED mdbx_canary mt_canary; #endif }; /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty. * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to * raise this on a 64 bit machine. */ #define CURSOR_STACK 32 struct MDB_xcursor; /** Cursors are used for all DB operations. * A cursor holds a path of (page pointer, key index) from the DB * root to a position in the DB, plus other state. #MDB_DUPSORT * cursors include an xcursor to the current data item. Write txns * track their cursors and keep them up to date when data moves. * Exception: An xcursor's pointer to a #P_SUBP page can be stale. * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage). */ struct MDB_cursor { #define MDBX_MC_SIGNATURE (0xFE05D5B1 ^ MDBX_MODE_SALT) #define MDBX_MC_READY4CLOSE (0x2817A047 ^ MDBX_MODE_SALT) #define MDBX_MC_WAIT4EOT (0x90E297A7 ^ MDBX_MODE_SALT) unsigned mc_signature; /** Next cursor on this DB in this txn */ MDB_cursor *mc_next; /** Backup of the original cursor if this cursor is a shadow */ MDB_cursor *mc_backup; /** Context used for databases with #MDB_DUPSORT, otherwise NULL */ struct MDB_xcursor *mc_xcursor; /** The transaction that owns this cursor */ MDB_txn *mc_txn; /** The database handle this cursor operates on */ MDB_dbi mc_dbi; /** The database record for this cursor */ MDB_db *mc_db; /** The database auxiliary record for this cursor */ MDB_dbx *mc_dbx; /** The @ref mt_dbflag for this database */ unsigned char *mc_dbflag; unsigned short mc_snum; /**< number of pushed pages */ unsigned short mc_top; /**< index of top page, normally mc_snum-1 */ /** @defgroup mdbx_cursor Cursor Flags * @ingroup internal * Cursor state flags. * @{ */ #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */ #define C_EOF 0x02 /**< No more data */ #define C_SUB 0x04 /**< Cursor is a sub-cursor */ #define C_DEL 0x08 /**< last op was a cursor_del */ #define C_UNTRACK 0x40 /**< Un-track cursor when closing */ #define C_RECLAIMING 0x80 /**< FreeDB lookup is prohibited */ /** @} */ unsigned mc_flags; /**< @ref mdbx_cursor */ MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */ indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */ }; /** Context for sorted-dup records. * We could have gone to a fully recursive design, with arbitrarily * deep nesting of sub-databases. But for now we only handle these * levels - main DB, optional sub-DB, sorted-duplicate DB. */ typedef struct MDB_xcursor { /** A sub-cursor for traversing the Dup DB */ MDB_cursor mx_cursor; /** The database record for this Dup DB */ MDB_db mx_db; /** The auxiliary DB record for this Dup DB */ MDB_dbx mx_dbx; /** The @ref mt_dbflag for this Dup DB */ unsigned char mx_dbflag; } MDB_xcursor; /** Check if there is an inited xcursor, so #XCURSOR_REFRESH() is proper */ #define XCURSOR_INITED(mc) \ ((mc)->mc_xcursor && ((mc)->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) /** Update sub-page pointer, if any, in \b mc->mc_xcursor. Needed * when the node which contains the sub-page may have moved. Called * with \b mp = mc->mc_pg[mc->mc_top], \b ki = mc->mc_ki[mc->mc_top]. */ #define XCURSOR_REFRESH(mc, mp, ki) \ do { \ MDB_page *xr_pg = (mp); \ MDB_node *xr_node = NODEPTR(xr_pg, ki); \ if ((xr_node->mn_flags & (F_DUPDATA | F_SUBDATA)) == F_DUPDATA) \ (mc)->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(xr_node); \ } while (0) /** State of FreeDB old pages, stored in the MDB_env */ typedef struct MDB_pgstate { pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */ txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */ } MDB_pgstate; /** Context for deferred cleanup of reader's threads. * to avoid https://github.com/ReOpen/ReOpenLDAP/issues/48 */ typedef struct MDBX_rthc { struct MDBX_rthc *rc_next; pthread_t rc_thread; MDB_reader *rc_reader; } MDBX_rthc; static MDBX_rthc *mdbx_rthc_get(pthread_key_t key); /** The database environment. */ struct MDB_env { #define MDBX_ME_SIGNATURE (0x9A899641 ^ MDBX_MODE_SALT) unsigned me_signature; HANDLE me_fd; /**< The main data file */ HANDLE me_lfd; /**< The lock file */ /** Failed to update the meta page. Probably an I/O error. */ #define MDB_FATAL_ERROR 0x80000000U /** Some fields are initialized. */ #define MDB_ENV_ACTIVE 0x20000000U /** me_txkey is set */ #define MDB_ENV_TXKEY 0x10000000U uint32_t me_flags; /**< @ref mdbx_env */ unsigned me_psize; /**< DB page size, inited from me_os_psize */ unsigned me_os_psize; /**< OS page size, from #GET_PAGESIZE */ unsigned me_maxreaders; /**< size of the reader table */ /** Max #MDB_txninfo.%mti_numreaders of interest to #mdbx_env_close() */ unsigned me_close_readers; MDB_dbi me_numdbs; /**< number of DBs opened */ MDB_dbi me_maxdbs; /**< size of the DB table */ pid_t me_pid; /**< process ID of this env */ char *me_path; /**< path to the DB files */ char *me_map; /**< the memory map of the data file */ MDB_txninfo *me_txns; /**< the memory map of the lock file, never NULL */ void *me_pbuf; /**< scratch area for DUPSORT put() */ MDB_txn *me_txn; /**< current write transaction */ MDB_txn *me_txn0; /**< prealloc'd write transaction */ size_t me_mapsize; /**< size of the data memory map */ pgno_t me_maxpg; /**< me_mapsize / me_psize */ MDB_dbx *me_dbxs; /**< array of static DB info */ uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */ unsigned *me_dbiseqs; /**< array of dbi sequence numbers */ pthread_key_t me_txkey; /**< thread-key for readers */ txnid_t me_pgoldest; /**< ID of oldest reader last time we looked */ MDB_pgstate me_pgstate; /**< state of old pages from freeDB */ #define me_pglast me_pgstate.mf_pglast #define me_pghead me_pgstate.mf_pghead MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */ /** IDL of pages that became unused in a write txn */ MDB_IDL me_free_pgs; /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */ MDB_ID2L me_dirty_list; /** Max number of freelist items that can fit in a single overflow page */ unsigned me_maxfree_1pg; /** Max size of a node on a page */ unsigned me_nodemax; unsigned me_maxkey_limit; /**< max size of a key */ int me_live_reader; /**< have liveness lock in reader table */ void *me_userctx; /**< User-settable context */ #if MDB_DEBUG MDB_assert_func *me_assert_func; /**< Callback for assertion failures */ #endif uint64_t me_sync_pending; /**< Total dirty/commited bytes since the last mdbx_env_sync() */ uint64_t me_sync_threshold; /**< Treshold of above to force synchronous flush */ #if MDBX_MODE_ENABLED MDBX_oom_func *me_oom_func; /**< Callback for kicking laggard readers */ #endif #ifdef USE_VALGRIND int me_valgrind_handle; #endif }; /** Nested transaction */ typedef struct MDB_ntxn { MDB_txn mnt_txn; /**< the transaction */ MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */ } MDB_ntxn; /** max number of pages to commit in one writev() call */ #define MDB_COMMIT_PAGES 64 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES #undef MDB_COMMIT_PAGES #define MDB_COMMIT_PAGES IOV_MAX #endif /** max bytes to write in one call */ #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4)) /** Check \b txn and \b dbi arguments to a function */ #define TXN_DBI_EXIST(txn, dbi, validity) \ ((dbi) < (txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity))) /** Check for misused \b dbi handles */ #define TXN_DBI_CHANGED(txn, dbi) \ ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi]) #define METAPAGE_1(env) (&((MDB_metabuf *)(env)->me_map)->mb_metabuf.mm_meta) #define METAPAGE_2(env) \ (&((MDB_metabuf *)((env)->me_map + env->me_psize))->mb_metabuf.mm_meta) static int mdbx_page_alloc(MDB_cursor *mc, int num, MDB_page **mp, int flags); static int mdbx_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp); static int mdbx_page_touch(MDB_cursor *mc); static int mdbx_cursor_touch(MDB_cursor *mc); #define MDB_END_NAMES \ { \ "committed", "empty-commit", "abort", "reset", "reset-tmp", "fail-begin", \ "fail-beginchild" \ } enum { /* mdbx_txn_end operation number, for logging */ MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET, MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD }; #define MDB_END_OPMASK 0x0F /**< mask for #mdbx_txn_end() operation number */ #define MDB_END_UPDATE 0x10 /**< update env state (DBIs) */ #define MDB_END_FREE 0x20 /**< free txn unless it is #MDB_env.%me_txn0 */ #define MDB_END_EOTDONE 0x40 /**< txn's cursors already closed */ #define MDB_END_SLOT MDB_NOTLS /**< release any reader slot if #MDB_NOTLS */ static int mdbx_txn_end(MDB_txn *txn, unsigned mode); static int mdbx_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **mp, int *lvl); static int mdbx_page_search_root(MDB_cursor *mc, MDB_val *key, int modify); #define MDB_PS_MODIFY 1 #define MDB_PS_ROOTONLY 2 #define MDB_PS_FIRST 4 #define MDB_PS_LAST 8 static int mdbx_page_search(MDB_cursor *mc, MDB_val *key, int flags); static int mdbx_page_merge(MDB_cursor *csrc, MDB_cursor *cdst); #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */ static int mdbx_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno, unsigned nflags); static int mdbx_env_read_header(MDB_env *env, MDB_meta *meta); static int mdbx_env_sync0(MDB_env *env, unsigned flags, MDB_meta *pending); static void mdbx_env_close0(MDB_env *env); static MDB_node *mdbx_node_search(MDB_cursor *mc, MDB_val *key, int *exactp); static int mdbx_node_add(MDB_cursor *mc, indx_t indx, MDB_val *key, MDB_val *data, pgno_t pgno, unsigned flags); static void mdbx_node_del(MDB_cursor *mc, int ksize); static void mdbx_node_shrink(MDB_page *mp, indx_t indx); static int mdbx_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft); static int mdbx_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data); static size_t mdbx_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data); static size_t mdbx_branch_size(MDB_env *env, MDB_val *key); static int mdbx_rebalance(MDB_cursor *mc); static int mdbx_update_key(MDB_cursor *mc, MDB_val *key); static void mdbx_cursor_pop(MDB_cursor *mc); static int mdbx_cursor_push(MDB_cursor *mc, MDB_page *mp); static int mdbx_cursor_del0(MDB_cursor *mc); static int mdbx_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags); static int mdbx_cursor_sibling(MDB_cursor *mc, int move_right); static int mdbx_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); static int mdbx_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); static int mdbx_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp); static int mdbx_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data); static int mdbx_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data); static void mdbx_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx); static void mdbx_xcursor_init0(MDB_cursor *mc); static void mdbx_xcursor_init1(MDB_cursor *mc, MDB_node *node); static void mdbx_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force); static int mdbx_drop0(MDB_cursor *mc, int subs); static int mdbx_reader_check0(MDB_env *env, int rlocked, int *dead); /** @cond */ static MDB_cmp_func mdbx_cmp_memn, mdbx_cmp_memnr, mdbx_cmp_int_ai, mdbx_cmp_int_a2, mdbx_cmp_int_ua; /** @endcond */ #ifdef __SANITIZE_THREAD__ static pthread_mutex_t tsan_mutex = PTHREAD_MUTEX_INITIALIZER; #endif /** Return the library version info. */ const char *mdbx_version(int *major, int *minor, int *patch) { if (major) *major = MDB_VERSION_MAJOR; if (minor) *minor = MDB_VERSION_MINOR; if (patch) *patch = MDB_VERSION_PATCH; return MDB_VERSION_STRING; } static const char *__mdbx_strerr(int errnum) { /* Table of descriptions for LMDB errors */ static const char *const tbl[] = { "MDB_KEYEXIST: Key/data pair already exists", "MDB_NOTFOUND: No matching key/data pair found", "MDB_PAGE_NOTFOUND: Requested page not found", "MDB_CORRUPTED: Located page was wrong data", "MDB_PANIC: Update of meta page failed or environment had fatal error", "MDB_VERSION_MISMATCH: DB version mismatch libmdbx", "MDB_INVALID: File is not an LMDB file", "MDB_MAP_FULL: Environment mapsize limit reached", "MDB_DBS_FULL: Too may DBI (maxdbs reached)", "MDB_READERS_FULL: Too many readers (maxreaders reached)", NULL /* -30789 unused in MDBX */, "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too " "big", "MDB_CURSOR_FULL: Internal error - cursor stack limit reached", "MDB_PAGE_FULL: Internal error - page has no more space", "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize", "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed", "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot", "MDB_BAD_TXN: Transaction must abort, has a child, or is invalid", "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong " "DUPFIXED size", "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly", "MDB_PROBLEM: Unexpected problem - txn should abort", }; if (errnum >= MDB_KEYEXIST && errnum <= MDB_LAST_ERRCODE) { int i = errnum - MDB_KEYEXIST; return tbl[i]; } switch (errnum) { case MDB_SUCCESS: return "MDB_SUCCESS: Successful"; case MDBX_EMULTIVAL: return "MDBX_EMULTIVAL: Unable to update multi-value for the given key"; case MDBX_EBADSIGN: return "MDBX_EBADSIGN: Wrong signature of a runtime object(s)"; default: return NULL; } } const char *mdbx_strerror_r(int errnum, char *buf, size_t buflen) { const char *msg = __mdbx_strerr(errnum); return msg ? msg : strerror_r(errnum, buf, buflen); } const char *__cold mdbx_strerror(int errnum) { const char *msg = __mdbx_strerr(errnum); return msg ? msg : strerror(errnum); } #if MDBX_MODE_ENABLED static txnid_t mdbx_oomkick(MDB_env *env, txnid_t oldest); #endif /* MDBX_MODE_ENABLED */ static void mdbx_debug_log(int type, const char *function, int line, const char *fmt, ...) __attribute__((format(printf, 4, 5))); #if MDB_DEBUG static txnid_t mdbx_debug_edge; static void __cold mdbx_assert_fail(MDB_env *env, const char *msg, const char *func, int line) { if (env && env->me_assert_func) env->me_assert_func(env, msg, func, line); else { if (mdbx_debug_logger) mdbx_debug_log(MDBX_DBG_ASSERT, func, line, "assert: %s\n", msg); __assert_fail(msg, __FILE__, line, func); } } #define mdbx_assert_enabled() unlikely(mdbx_runtime_flags &MDBX_DBG_ASSERT) #define mdbx_audit_enabled() unlikely(mdbx_runtime_flags &MDBX_DBG_AUDIT) #define mdbx_debug_enabled(type) \ unlikely(mdbx_runtime_flags &(type & (MDBX_DBG_TRACE | MDBX_DBG_EXTRA))) #else #ifndef NDEBUG #define mdbx_debug_enabled(type) (1) #else #define mdbx_debug_enabled(type) (0) #endif #define mdbx_audit_enabled() (0) #define mdbx_assert_enabled() (0) #define mdbx_assert_fail(env, msg, func, line) \ __assert_fail(msg, __FILE__, line, func) #endif /* MDB_DEBUG */ static void __cold mdbx_debug_log(int type, const char *function, int line, const char *fmt, ...) { va_list args; va_start(args, fmt); if (mdbx_debug_logger) mdbx_debug_logger(type, function, line, fmt, args); else { if (function && line > 0) fprintf(stderr, "%s:%d ", function, line); else if (function) fprintf(stderr, "%s: ", function); else if (line > 0) fprintf(stderr, "%d: ", line); vfprintf(stderr, fmt, args); } va_end(args); } #define mdbx_print(fmt, ...) \ mdbx_debug_log(MDBX_DBG_PRINT, NULL, 0, fmt, ##__VA_ARGS__) #define mdbx_debug(fmt, ...) \ do { \ if (mdbx_debug_enabled(MDBX_DBG_TRACE)) \ mdbx_debug_log(MDBX_DBG_TRACE, __FUNCTION__, __LINE__, fmt "\n", \ ##__VA_ARGS__); \ } while (0) #define mdbx_debug_print(fmt, ...) \ do { \ if (mdbx_debug_enabled(MDBX_DBG_TRACE)) \ mdbx_debug_log(MDBX_DBG_TRACE, NULL, 0, fmt, ##__VA_ARGS__); \ } while (0) #define mdbx_debug_extra(fmt, ...) \ do { \ if (mdbx_debug_enabled(MDBX_DBG_EXTRA)) \ mdbx_debug_log(MDBX_DBG_EXTRA, __FUNCTION__, __LINE__, fmt, \ ##__VA_ARGS__); \ } while (0) #define mdbx_debug_extra_print(fmt, ...) \ do { \ if (mdbx_debug_enabled(MDBX_DBG_EXTRA)) \ mdbx_debug_log(MDBX_DBG_EXTRA, NULL, 0, fmt, ##__VA_ARGS__); \ } while (0) #define mdbx_ensure_msg(env, expr, msg) \ do { \ if (unlikely(!(expr))) \ mdbx_assert_fail(env, msg, __FUNCTION__, __LINE__); \ } while (0) #define mdbx_ensure(env, expr) mdbx_ensure_msg(env, expr, #expr) /** assert(3) variant in environment context */ #define mdbx_assert(env, expr) \ do { \ if (mdbx_assert_enabled()) \ mdbx_ensure(env, expr); \ } while (0) /** assert(3) variant in cursor context */ #define mdbx_cassert(mc, expr) mdbx_assert((mc)->mc_txn->mt_env, expr) /** assert(3) variant in transaction context */ #define mdbx_tassert(txn, expr) mdbx_assert((txn)->mt_env, expr) /** Return the page number of \b mp which may be sub-page, for debug output */ static MDBX_INLINE pgno_t mdbx_dbg_pgno(MDB_page *mp) { pgno_t ret; COPY_PGNO(ret, mp->mp_pgno); return ret; } /** Display a key in hexadecimal and return the address of the result. * @param[in] key the key to display * @param[in] buf the buffer to write into. Should always be #DKBUF. * @return The key in hexadecimal form. */ char *mdbx_dkey(MDB_val *key, char *buf) { char *ptr = buf; unsigned i; if (!key) return ""; if (key->mv_size > DKBUF_MAXKEYSIZE) return "MDB_MAXKEYSIZE"; /* may want to make this a dynamic check: if the key is mostly * printable characters, print it as-is instead of converting to hex. */ #if 1 buf[0] = '\0'; for (i = 0; i < key->mv_size; i++) ptr += sprintf(ptr, "%02x", ((unsigned char *)key->mv_data)[i]); #else sprintf(buf, "%.*s", key->mv_size, key->mv_data); #endif return buf; } #if 0 /* LY: debug stuff */ static const char * mdbx_leafnode_type(MDB_node *n) { static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}}; return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" : tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)]; } /** Display all the keys in the page. */ static void mdbx_page_list(MDB_page *mp) { pgno_t pgno = mdbx_dbg_pgno(mp); const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : ""; MDB_node *node; unsigned i, nkeys, nsize, total = 0; MDB_val key; DKBUF; switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) { case P_BRANCH: type = "Branch page"; break; case P_LEAF: type = "Leaf page"; break; case P_LEAF|P_SUBP: type = "Sub-page"; break; case P_LEAF|P_LEAF2: type = "LEAF2 page"; break; case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break; case P_OVERFLOW: mdbx_print("Overflow page %zu pages %u%s\n", pgno, mp->mp_pages, state); return; case P_META: mdbx_print("Meta-page %zu txnid %zu\n", pgno, ((MDB_meta *)PAGEDATA(mp))->mm_txnid); return; default: mdbx_print("Bad page %zu flags 0x%X\n", pgno, mp->mp_flags); return; } nkeys = NUMKEYS(mp); mdbx_print("%s %zu numkeys %u%s\n", type, pgno, nkeys, state); for (i=0; imp_leaf2_ksize; key.mv_data = LEAF2KEY(mp, i, nsize); total += nsize; mdbx_print("key %u: nsize %u, %s\n", i, nsize, DKEY(&key)); continue; } node = NODEPTR(mp, i); key.mv_size = node->mn_ksize; key.mv_data = node->mn_data; nsize = NODESIZE + key.mv_size; if (IS_BRANCH(mp)) { mdbx_print("key %u: page %zu, %s\n", i, NODEPGNO(node), DKEY(&key)); total += nsize; } else { if (F_ISSET(node->mn_flags, F_BIGDATA)) nsize += sizeof(pgno_t); else nsize += NODEDSZ(node); total += nsize; nsize += sizeof(indx_t); mdbx_print("key %u: nsize %u, %s%s\n", i, nsize, DKEY(&key), mdbx_leafnode_type(node)); } total = EVEN(total); } mdbx_print("Total: header %u + contents %u + unused %u\n", IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp)); } static void mdbx_cursor_chk(MDB_cursor *mc) { unsigned i; MDB_node *node; MDB_page *mp; if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return; for (i=0; imc_top; i++) { mp = mc->mc_pg[i]; node = NODEPTR(mp, mc->mc_ki[i]); if (unlikely(NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)) mdbx_print("oops!\n"); } if (unlikely(mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))) mdbx_print("ack!\n"); if (XCURSOR_INITED(mc)) { node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) && mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) { mdbx_print("blah!\n"); } } } #endif /* 0 */ /** Count all the pages in each DB and in the freelist * and make sure it matches the actual number of pages * being used. * All named DBs must be open for a correct count. */ static void mdbx_audit(MDB_txn *txn) { MDB_cursor mc; MDB_val key, data; MDB_ID freecount, count; MDB_dbi i; int rc; freecount = 0; mdbx_cursor_init(&mc, txn, FREE_DBI, NULL); while ((rc = mdbx_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0) freecount += *(MDB_ID *)data.mv_data; mdbx_tassert(txn, rc == MDB_NOTFOUND); count = 0; for (i = 0; i < txn->mt_numdbs; i++) { MDB_xcursor mx; if (!(txn->mt_dbflags[i] & DB_VALID)) continue; mdbx_cursor_init(&mc, txn, i, &mx); if (txn->mt_dbs[i].md_root == P_INVALID) continue; count += txn->mt_dbs[i].md_branch_pages + txn->mt_dbs[i].md_leaf_pages + txn->mt_dbs[i].md_overflow_pages; if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) { rc = mdbx_page_search(&mc, NULL, MDB_PS_FIRST); for (; rc == MDB_SUCCESS; rc = mdbx_cursor_sibling(&mc, 1)) { unsigned j; MDB_page *mp; mp = mc.mc_pg[mc.mc_top]; for (j = 0; j < NUMKEYS(mp); j++) { MDB_node *leaf = NODEPTR(mp, j); if (leaf->mn_flags & F_SUBDATA) { MDB_db db; memcpy(&db, NODEDATA(leaf), sizeof(db)); count += db.md_branch_pages + db.md_leaf_pages + db.md_overflow_pages; } } } mdbx_tassert(txn, rc == MDB_NOTFOUND); } } if (freecount + count + NUM_METAS != txn->mt_next_pgno) { mdbx_print( "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n", txn->mt_txnid, freecount, count + NUM_METAS, freecount + count + NUM_METAS, txn->mt_next_pgno); } } int mdbx_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) { mdbx_ensure(NULL, txn->mt_signature == MDBX_MT_SIGNATURE); return txn->mt_dbxs[dbi].md_cmp(a, b); } int mdbx_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) { mdbx_ensure(NULL, txn->mt_signature == MDBX_MT_SIGNATURE); return txn->mt_dbxs[dbi].md_dcmp(a, b); } /** Allocate memory for a page. * Re-use old malloc'd pages first for singletons, otherwise just malloc. * Set #MDB_TXN_ERROR on failure. */ static MDB_page *mdbx_page_malloc(MDB_txn *txn, unsigned num) { MDB_env *env = txn->mt_env; size_t size = env->me_psize; MDB_page *np = env->me_dpages; if (likely(num == 1 && np)) { ASAN_UNPOISON_MEMORY_REGION(np, size); VALGRIND_MEMPOOL_ALLOC(env, np, size); VALGRIND_MAKE_MEM_DEFINED(&np->mp_next, sizeof(np->mp_next)); env->me_dpages = np->mp_next; } else { size *= num; np = malloc(size); if (unlikely(!np)) { txn->mt_flags |= MDB_TXN_ERROR; return np; } VALGRIND_MEMPOOL_ALLOC(env, np, size); } if ((env->me_flags & MDB_NOMEMINIT) == 0) { /* For a single page alloc, we init everything after the page header. * For multi-page, we init the final page; if the caller needed that * many pages they will be filling in at least up to the last page. */ size_t skip = PAGEHDRSZ; if (num > 1) skip += (num - 1) * env->me_psize; memset((char *)np + skip, 0, size - skip); } VALGRIND_MAKE_MEM_UNDEFINED(np, size); np->mp_flags = 0; np->mp_pages = num; return np; } /** Free a single page. * Saves single pages to a list, for future reuse. * (This is not used for multi-page overflow pages.) */ static MDBX_INLINE void mdbx_page_free(MDB_env *env, MDB_page *mp) { mp->mp_next = env->me_dpages; VALGRIND_MEMPOOL_FREE(env, mp); env->me_dpages = mp; } /** Free a dirty page */ static void mdbx_dpage_free(MDB_env *env, MDB_page *dp) { if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) { mdbx_page_free(env, dp); } else { /* large pages just get freed directly */ VALGRIND_MEMPOOL_FREE(env, dp); free(dp); } } /** Return all dirty pages to dpage list */ static void mdbx_dlist_free(MDB_txn *txn) { MDB_env *env = txn->mt_env; MDB_ID2L dl = txn->mt_u.dirty_list; unsigned i, n = dl[0].mid; for (i = 1; i <= n; i++) { mdbx_dpage_free(env, dl[i].mptr); } dl[0].mid = 0; } static void __cold mdbx_kill_page(MDB_env *env, pgno_t pgno) { const size_t offs = env->me_psize * pgno; const size_t shift = offsetof(MDB_page, mp_pb); if (env->me_flags & MDB_WRITEMAP) { MDB_page *mp = (MDB_page *)(env->me_map + offs); memset(&mp->mp_pb, 0x6F /* 'o', 111 */, env->me_psize - shift); VALGRIND_MAKE_MEM_NOACCESS(&mp->mp_pb, env->me_psize - shift); ASAN_POISON_MEMORY_REGION(&mp->mp_pb, env->me_psize - shift); } else { struct iovec iov[1]; iov[0].iov_len = env->me_psize - shift; iov[0].iov_base = alloca(iov[0].iov_len); memset(iov[0].iov_base, 0x6F /* 'o', 111 */, iov[0].iov_len); ssize_t rc = pwritev(env->me_fd, iov, 1, offs + shift); assert(rc == (ssize_t)iov[0].iov_len); (void)rc; } } /** Loosen or free a single page. * Saves single pages to a list for future reuse * in this same txn. It has been pulled from the freeDB * and already resides on the dirty list, but has been * deleted. Use these pages first before pulling again * from the freeDB. * * If the page wasn't dirtied in this txn, just add it * to this txn's free list. */ static int mdbx_page_loose(MDB_cursor *mc, MDB_page *mp) { int loose = 0; pgno_t pgno = mp->mp_pgno; MDB_txn *txn = mc->mc_txn; if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) { if (txn->mt_parent) { MDB_ID2 *dl = txn->mt_u.dirty_list; /* If txn has a parent, make sure the page is in our * dirty list. */ if (dl[0].mid) { unsigned x = mdbx_mid2l_search(dl, pgno); if (x <= dl[0].mid && dl[x].mid == pgno) { if (unlikely(mp != dl[x].mptr)) { /* bad cursor? */ mc->mc_flags &= ~(C_INITIALIZED | C_EOF); txn->mt_flags |= MDB_TXN_ERROR; return MDB_PROBLEM; } /* ok, it's ours */ loose = 1; } } } else { /* no parent txn, so it's just ours */ loose = 1; } } if (loose) { mdbx_debug("loosen db %d page %zu", DDBI(mc), mp->mp_pgno); MDB_page **link = &NEXT_LOOSE_PAGE(mp); if (unlikely(txn->mt_env->me_flags & MDBX_PAGEPERTURB)) { mdbx_kill_page(txn->mt_env, pgno); VALGRIND_MAKE_MEM_UNDEFINED(link, sizeof(MDB_page *)); ASAN_UNPOISON_MEMORY_REGION(link, sizeof(MDB_page *)); } *link = txn->mt_loose_pgs; txn->mt_loose_pgs = mp; txn->mt_loose_count++; mp->mp_flags |= P_LOOSE; } else { int rc = mdbx_midl_append(&txn->mt_free_pgs, pgno); if (unlikely(rc)) return rc; } return MDB_SUCCESS; } /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn. * @param[in] mc A cursor handle for the current operation. * @param[in] pflags Flags of the pages to update: * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it. * @param[in] all No shortcuts. Needed except after a full #mdbx_page_flush(). * @return 0 on success, non-zero on failure. */ static int mdbx_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all) { enum { Mask = P_SUBP | P_DIRTY | P_LOOSE | P_KEEP }; MDB_txn *txn = mc->mc_txn; MDB_cursor *m3, *m0 = mc; MDB_xcursor *mx; MDB_page *dp, *mp; MDB_node *leaf; unsigned i, j; int rc = MDB_SUCCESS, level; /* Mark pages seen by cursors: First m0, then tracked cursors */ for (i = txn->mt_numdbs;;) { if (mc->mc_flags & C_INITIALIZED) { for (m3 = mc;; m3 = &mx->mx_cursor) { mp = NULL; for (j = 0; j < m3->mc_snum; j++) { mp = m3->mc_pg[j]; if ((mp->mp_flags & Mask) == pflags) mp->mp_flags ^= P_KEEP; } mx = m3->mc_xcursor; /* Proceed to mx if it is at a sub-database */ if (!(mx && (mx->mx_cursor.mc_flags & C_INITIALIZED))) break; if (!(mp && (mp->mp_flags & P_LEAF))) break; leaf = NODEPTR(mp, m3->mc_ki[j - 1]); if (!(leaf->mn_flags & F_SUBDATA)) break; } } mc = mc->mc_next; for (; !mc || mc == m0; mc = txn->mt_cursors[--i]) if (i == 0) goto mark_done; } mark_done: if (all) { /* Mark dirty root pages */ for (i = 0; i < txn->mt_numdbs; i++) { if (txn->mt_dbflags[i] & DB_DIRTY) { pgno_t pgno = txn->mt_dbs[i].md_root; if (pgno == P_INVALID) continue; if (unlikely((rc = mdbx_page_get(m0, pgno, &dp, &level)) != MDB_SUCCESS)) break; if ((dp->mp_flags & Mask) == pflags && level <= 1) dp->mp_flags ^= P_KEEP; } } } return rc; } static int mdbx_page_flush(MDB_txn *txn, int keep); /** Spill pages from the dirty list back to disk. * This is intended to prevent running into #MDB_TXN_FULL situations, * but note that they may still occur in a few cases: * 1) our estimate of the txn size could be too small. Currently this * seems unlikely, except with a large number of #MDB_MULTIPLE items. * 2) child txns may run out of space if their parents dirtied a * lot of pages and never spilled them. TODO: we probably should do * a preemptive spill during #mdbx_txn_begin() of a child txn, if * the parent's dirty_room is below a given threshold. * * Otherwise, if not using nested txns, it is expected that apps will * not run into #MDB_TXN_FULL any more. The pages are flushed to disk * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared. * If the txn never references them again, they can be left alone. * If the txn only reads them, they can be used without any fuss. * If the txn writes them again, they can be dirtied immediately without * going thru all of the work of #mdbx_page_touch(). Such references are * handled by #mdbx_page_unspill(). * * Also note, we never spill DB root pages, nor pages of active cursors, * because we'll need these back again soon anyway. And in nested txns, * we can't spill a page in a child txn if it was already spilled in a * parent txn. That would alter the parent txns' data even though * the child hasn't committed yet, and we'd have no way to undo it if * the child aborted. * * @param[in] m0 cursor A cursor handle identifying the transaction and * database for which we are checking space. * @param[in] key For a put operation, the key being stored. * @param[in] data For a put operation, the data being stored. * @return 0 on success, non-zero on failure. */ static int mdbx_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data) { MDB_txn *txn = m0->mc_txn; MDB_page *dp; MDB_ID2L dl = txn->mt_u.dirty_list; unsigned i, j, need; int rc; if (m0->mc_flags & C_SUB) return MDB_SUCCESS; /* Estimate how much space this op will take */ i = m0->mc_db->md_depth; /* Named DBs also dirty the main DB */ if (m0->mc_dbi >= CORE_DBS) i += txn->mt_dbs[MAIN_DBI].md_depth; /* For puts, roughly factor in the key+data size */ if (key) i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize; i += i; /* double it for good measure */ need = i; if (txn->mt_dirty_room > i) return MDB_SUCCESS; if (!txn->mt_spill_pgs) { txn->mt_spill_pgs = mdbx_midl_alloc(MDB_IDL_UM_MAX); if (unlikely(!txn->mt_spill_pgs)) return ENOMEM; } else { /* purge deleted slots */ MDB_IDL sl = txn->mt_spill_pgs; unsigned num = sl[0]; j = 0; for (i = 1; i <= num; i++) { if (!(sl[i] & 1)) sl[++j] = sl[i]; } sl[0] = j; } /* Preserve pages which may soon be dirtied again */ rc = mdbx_pages_xkeep(m0, P_DIRTY, 1); if (unlikely(rc != MDB_SUCCESS)) goto bailout; /* Less aggressive spill - we originally spilled the entire dirty list, * with a few exceptions for cursor pages and DB root pages. But this * turns out to be a lot of wasted effort because in a large txn many * of those pages will need to be used again. So now we spill only 1/8th * of the dirty pages. Testing revealed this to be a good tradeoff, * better than 1/2, 1/4, or 1/10. */ if (need < MDB_IDL_UM_MAX / 8) need = MDB_IDL_UM_MAX / 8; /* Save the page IDs of all the pages we're flushing */ /* flush from the tail forward, this saves a lot of shifting later on. */ for (i = dl[0].mid; i && need; i--) { MDB_ID pn = dl[i].mid << 1; dp = dl[i].mptr; if (dp->mp_flags & (P_LOOSE | P_KEEP)) continue; /* Can't spill twice, make sure it's not already in a parent's * spill list. */ if (txn->mt_parent) { MDB_txn *tx2; for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) { if (tx2->mt_spill_pgs) { j = mdbx_midl_search(tx2->mt_spill_pgs, pn); if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) { dp->mp_flags |= P_KEEP; break; } } } if (tx2) continue; } rc = mdbx_midl_append(&txn->mt_spill_pgs, pn); if (unlikely(rc != MDB_SUCCESS)) goto bailout; need--; } mdbx_midl_sort(txn->mt_spill_pgs); /* Flush the spilled part of dirty list */ rc = mdbx_page_flush(txn, i); if (unlikely(rc != MDB_SUCCESS)) goto bailout; /* Reset any dirty pages we kept that page_flush didn't see */ rc = mdbx_pages_xkeep(m0, P_DIRTY | P_KEEP, i); bailout: txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS; return rc; } static MDBX_INLINE uint64_t mdbx_meta_sign(MDB_meta *meta) { uint64_t sign = MDB_DATASIGN_NONE; #if 0 /* TODO */ sign = hippeus_hash64( &meta->mm_mapsize, sizeof(MDB_meta) - offsetof(MDB_meta, mm_mapsize), meta->mm_version | (uint64_t) MDB_MAGIC << 32 ); #else (void)meta; #endif /* LY: newer returns MDB_DATASIGN_NONE or MDB_DATASIGN_WEAK */ return (sign > MDB_DATASIGN_WEAK) ? sign : ~sign; } static MDBX_INLINE MDB_meta *mdbx_meta_head_w(MDB_env *env) { MDB_meta *a = METAPAGE_1(env); MDB_meta *b = METAPAGE_2(env); txnid_t head_txnid = env->me_txns->mti_txnid; mdbx_assert(env, a->mm_txnid != b->mm_txnid || head_txnid == 0); if (a->mm_txnid == head_txnid) return a; if (likely(b->mm_txnid == head_txnid)) return b; mdbx_debug("me_txns->mti_txnid not match meta-pages"); mdbx_assert(env, head_txnid == a->mm_txnid || head_txnid == b->mm_txnid); env->me_flags |= MDB_FATAL_ERROR; return a; } static MDB_meta *mdbx_meta_head_r(MDB_env *env) { MDB_meta *a = METAPAGE_1(env); MDB_meta *b = METAPAGE_2(env), *h; #ifdef __SANITIZE_THREAD__ pthread_mutex_lock(&tsan_mutex); #endif txnid_t head_txnid = env->me_txns->mti_txnid; mdbx_assert(env, a->mm_txnid != b->mm_txnid || head_txnid == 0); if (likely(a->mm_txnid == head_txnid)) { h = a; } else if (likely(b->mm_txnid == head_txnid)) { h = b; } else { /* LY: seems got a collision with mdbx_env_sync0() */ mdbx_coherent_barrier(); head_txnid = env->me_txns->mti_txnid; mdbx_assert(env, a->mm_txnid != b->mm_txnid || head_txnid == 0); if (likely(a->mm_txnid == head_txnid)) { h = a; } else if (likely(b->mm_txnid == head_txnid)) { h = b; } else { /* LY: got a race again, or DB is corrupted */ int rc = mdbx_mutex_lock(env, MDB_MUTEX(env, w)); h = mdbx_meta_head_w(env); if (rc == 0) mdbx_mutex_unlock(env, MDB_MUTEX(env, w)); } } #ifdef __SANITIZE_THREAD__ pthread_mutex_unlock(&tsan_mutex); #endif return h; } static MDBX_INLINE MDB_meta *mdbx_env_meta_flipflop(const MDB_env *env, MDB_meta *meta) { return (meta == METAPAGE_1(env)) ? METAPAGE_2(env) : METAPAGE_1(env); } static MDBX_INLINE int mdbx_meta_lt(MDB_meta *a, MDB_meta *b) { return (META_IS_STEADY(a) == META_IS_STEADY(b)) ? a->mm_txnid < b->mm_txnid : META_IS_STEADY(b); } /** Find oldest txnid still referenced. */ static txnid_t mdbx_find_oldest(MDB_env *env, int *laggard) { #ifdef __SANITIZE_THREAD__ pthread_mutex_lock(&tsan_mutex); #endif int i, reader; MDB_reader *r = env->me_txns->mti_readers; txnid_t oldest = env->me_txns->mti_txnid; MDB_meta *a = METAPAGE_1(env); MDB_meta *b = METAPAGE_2(env); if (META_IS_WEAK(a) && oldest > b->mm_txnid) oldest = b->mm_txnid; if (META_IS_WEAK(b) && oldest > a->mm_txnid) oldest = a->mm_txnid; for (reader = -1, i = env->me_txns->mti_numreaders; --i >= 0;) { if (r[i].mr_pid) { txnid_t snap = r[i].mr_txnid; if (oldest > snap) { oldest = snap; reader = i; } } } #ifdef __SANITIZE_THREAD__ pthread_mutex_unlock(&tsan_mutex); #endif if (laggard) *laggard = reader; return env->me_pgoldest = oldest; } /** Add a page to the txn's dirty list */ static void mdbx_page_dirty(MDB_txn *txn, MDB_page *mp) { MDB_ID2 mid; int rc, (*insert)(MDB_ID2L, MDB_ID2 *); if (txn->mt_flags & MDB_TXN_WRITEMAP) { insert = mdbx_mid2l_append; } else { insert = mdbx_mid2l_insert; } mid.mid = mp->mp_pgno; mid.mptr = mp; rc = insert(txn->mt_u.dirty_list, &mid); mdbx_tassert(txn, rc == 0); txn->mt_dirty_room--; } /** Allocate page numbers and memory for writing. Maintain me_pglast, * me_pghead and mt_next_pgno. Set #MDB_TXN_ERROR on failure. * * If there are free pages available from older transactions, they * are re-used first. Otherwise allocate a new page at mt_next_pgno. * Do not modify the freedB, just merge freeDB records into me_pghead[] * and move me_pglast to say which records were consumed. Only this * function can create me_pghead and move me_pglast/mt_next_pgno. * @param[in] mc cursor A cursor handle identifying the transaction and * database for which we are allocating. * @param[in] num the number of pages to allocate. * @param[out] mp Address of the allocated page(s). Requests for multiple *pages * will always be satisfied by a single contiguous chunk of memory. * @return 0 on success, non-zero on failure. */ #define MDBX_ALLOC_CACHE 1 #define MDBX_ALLOC_GC 2 #define MDBX_ALLOC_NEW 4 #define MDBX_ALLOC_KICK 8 #define MDBX_ALLOC_ALL \ (MDBX_ALLOC_CACHE | MDBX_ALLOC_GC | MDBX_ALLOC_NEW | MDBX_ALLOC_KICK) static int mdbx_page_alloc(MDB_cursor *mc, int num, MDB_page **mp, int flags) { int rc; MDB_txn *txn = mc->mc_txn; MDB_env *env = txn->mt_env; pgno_t pgno, *mop = env->me_pghead; unsigned i = 0, j, mop_len = mop ? mop[0] : 0, n2 = num - 1; MDB_page *np; txnid_t oldest = 0, last = 0; MDB_cursor_op op; MDB_cursor m2; int found_oldest = 0; if (likely(flags & MDBX_ALLOC_GC)) { flags |= env->me_flags & (MDBX_COALESCE | MDBX_LIFORECLAIM); if (unlikely(mc->mc_flags & C_RECLAIMING)) { /* If mc is updating the freeDB, then the freelist cannot play * catch-up with itself by growing while trying to save it. */ flags &= ~(MDBX_ALLOC_GC | MDBX_ALLOC_KICK | MDBX_COALESCE | MDBX_LIFORECLAIM); } } if (likely(flags & MDBX_ALLOC_CACHE)) { /* If there are any loose pages, just use them */ assert(mp && num); if (likely(num == 1 && txn->mt_loose_pgs)) { np = txn->mt_loose_pgs; txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np); txn->mt_loose_count--; mdbx_debug("db %d use loose page %zu", DDBI(mc), np->mp_pgno); ASAN_UNPOISON_MEMORY_REGION(np, env->me_psize); *mp = np; return MDB_SUCCESS; } } /* If our dirty list is already full, we can't do anything */ if (unlikely(txn->mt_dirty_room == 0)) { rc = MDB_TXN_FULL; goto fail; } for (;;) { /* oom-kick retry loop */ for (op = MDB_FIRST;; op = (flags & MDBX_LIFORECLAIM) ? MDB_PREV : MDB_NEXT) { MDB_val key, data; MDB_node *leaf; pgno_t *idl; /* Seek a big enough contiguous page range. Prefer * pages at the tail, just truncating the list. */ if (likely(flags & MDBX_ALLOC_CACHE) && mop_len > n2 && (!(flags & MDBX_COALESCE) || op == MDB_FIRST)) { i = mop_len; do { pgno = mop[i]; if (likely(mop[i - n2] == pgno + n2)) goto done; } while (--i > n2); } if (op == MDB_FIRST) { /* 1st iteration */ /* Prepare to fetch more and coalesce */ if (unlikely(!(flags & MDBX_ALLOC_GC))) break; oldest = env->me_pgoldest; mdbx_cursor_init(&m2, txn, FREE_DBI, NULL); if (flags & MDBX_LIFORECLAIM) { if (!found_oldest) { oldest = mdbx_find_oldest(env, NULL); found_oldest = 1; } /* Begin from oldest reader if any */ if (oldest > 2) { last = oldest - 1; op = MDB_SET_RANGE; } } else if (env->me_pglast) { /* Continue lookup from env->me_pglast to higher/last */ last = env->me_pglast; op = MDB_SET_RANGE; } key.mv_data = &last; key.mv_size = sizeof(last); } if (!(flags & MDBX_LIFORECLAIM)) { /* Do not fetch more if the record will be too recent */ if (op != MDB_FIRST && ++last >= oldest) { if (!found_oldest) { oldest = mdbx_find_oldest(env, NULL); found_oldest = 1; } if (oldest <= last) break; } } rc = mdbx_cursor_get(&m2, &key, NULL, op); if (rc == MDB_NOTFOUND && (flags & MDBX_LIFORECLAIM)) { if (op == MDB_SET_RANGE) continue; found_oldest = 1; if (oldest < mdbx_find_oldest(env, NULL)) { oldest = env->me_pgoldest; last = oldest - 1; key.mv_data = &last; key.mv_size = sizeof(last); op = MDB_SET_RANGE; rc = mdbx_cursor_get(&m2, &key, NULL, op); } } if (unlikely(rc)) { if (rc == MDB_NOTFOUND) break; goto fail; } last = *(txnid_t *)key.mv_data; if (oldest <= last) { if (!found_oldest) { oldest = mdbx_find_oldest(env, NULL); found_oldest = 1; } if (oldest <= last) { if (flags & MDBX_LIFORECLAIM) continue; break; } } if (flags & MDBX_LIFORECLAIM) { if (txn->mt_lifo_reclaimed) { for (j = txn->mt_lifo_reclaimed[0]; j > 0; --j) if (txn->mt_lifo_reclaimed[j] == last) break; if (j) continue; } } np = m2.mc_pg[m2.mc_top]; leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]); if (unlikely((rc = mdbx_node_read(&m2, leaf, &data)) != MDB_SUCCESS)) goto fail; if ((flags & MDBX_LIFORECLAIM) && !txn->mt_lifo_reclaimed) { txn->mt_lifo_reclaimed = mdbx_midl_alloc(env->me_maxfree_1pg); if (unlikely(!txn->mt_lifo_reclaimed)) { rc = ENOMEM; goto fail; } } idl = (MDB_ID *)data.mv_data; mdbx_tassert(txn, idl[0] == 0 || data.mv_size == (idl[0] + 1) * sizeof(MDB_ID)); i = idl[0]; if (!mop) { if (unlikely(!(env->me_pghead = mop = mdbx_midl_alloc(i)))) { rc = ENOMEM; goto fail; } } else { if (unlikely((rc = mdbx_midl_need(&env->me_pghead, i)) != 0)) goto fail; mop = env->me_pghead; } if (flags & MDBX_LIFORECLAIM) { if ((rc = mdbx_midl_append(&txn->mt_lifo_reclaimed, last)) != 0) goto fail; } env->me_pglast = last; if (mdbx_debug_enabled(MDBX_DBG_EXTRA)) { mdbx_debug_extra("IDL read txn %zu root %zu num %u, IDL", last, txn->mt_dbs[FREE_DBI].md_root, i); for (j = i; j; j--) mdbx_debug_extra_print(" %zu", idl[j]); mdbx_debug_extra_print("\n"); } /* Merge in descending sorted order */ mdbx_midl_xmerge(mop, idl); mop_len = mop[0]; if (unlikely((flags & MDBX_ALLOC_CACHE) == 0)) { /* force gc reclaim mode */ return MDB_SUCCESS; } /* Don't try to coalesce too much. */ if (mop_len > MDB_IDL_UM_SIZE / 2) break; if (flags & MDBX_COALESCE) { if (mop_len /* current size */ >= env->me_maxfree_1pg / 2 || i /* prev size */ >= env->me_maxfree_1pg / 4) flags &= ~MDBX_COALESCE; } } if ((flags & (MDBX_COALESCE | MDBX_ALLOC_CACHE)) == (MDBX_COALESCE | MDBX_ALLOC_CACHE) && mop_len > n2) { i = mop_len; do { pgno = mop[i]; if (mop[i - n2] == pgno + n2) goto done; } while (--i > n2); } /* Use new pages from the map when nothing suitable in the freeDB */ i = 0; pgno = txn->mt_next_pgno; rc = MDB_MAP_FULL; if (likely(pgno + num <= env->me_maxpg)) { rc = MDB_NOTFOUND; if (likely(flags & MDBX_ALLOC_NEW)) goto done; } if ((flags & MDBX_ALLOC_GC) && ((flags & MDBX_ALLOC_KICK) || rc == MDB_MAP_FULL)) { MDB_meta *head = mdbx_meta_head_w(env); MDB_meta *tail = mdbx_env_meta_flipflop(env, head); if (oldest == tail->mm_txnid && META_IS_WEAK(head) && !META_IS_WEAK(tail)) { MDB_meta meta = *head; /* LY: Here an oom was happened: * - all pages had allocated; * - reclaiming was stopped at the last steady-sync; * - the head-sync is weak. * Now we need make a sync to resume reclaiming. If both * MDB_NOSYNC and MDB_MAPASYNC flags are set, then assume that * utterly no-sync write mode was requested. In such case * don't make a steady-sync, but only a legacy-mode checkpoint, * just for resume reclaiming only, not for data consistency. */ mdbx_debug("kick-gc: head %zu/%c, tail %zu/%c, oldest %zu, txnid %zu", head->mm_txnid, META_IS_WEAK(head) ? 'W' : 'N', tail->mm_txnid, META_IS_WEAK(tail) ? 'W' : 'N', oldest, env->me_txns->mt1.mtb.mtb_txnid); int flags = env->me_flags & MDB_WRITEMAP; if ((env->me_flags & MDBX_UTTERLY_NOSYNC) == MDBX_UTTERLY_NOSYNC) flags |= MDBX_UTTERLY_NOSYNC; mdbx_assert(env, env->me_sync_pending > 0); if (mdbx_env_sync0(env, flags, &meta) == MDB_SUCCESS) { txnid_t snap = mdbx_find_oldest(env, NULL); if (snap > oldest) { continue; } } } if (rc == MDB_MAP_FULL) { #if MDBX_MODE_ENABLED txnid_t snap = mdbx_oomkick(env, oldest); #else mdbx_debug("DB size maxed out"); txnid_t snap = mdbx_find_oldest(env, NULL); #endif /* MDBX_MODE_ENABLED */ if (snap > oldest) { oldest = snap; continue; } } } fail: if (mp) { *mp = NULL; txn->mt_flags |= MDB_TXN_ERROR; } assert(rc); return rc; } done: assert(mp && num); if (env->me_flags & MDB_WRITEMAP) { np = (MDB_page *)(env->me_map + env->me_psize * pgno); /* LY: reset no-access flag from mdbx_kill_page() */ VALGRIND_MAKE_MEM_UNDEFINED(np, env->me_psize * num); ASAN_UNPOISON_MEMORY_REGION(np, env->me_psize * num); } else { if (unlikely(!(np = mdbx_page_malloc(txn, num)))) { rc = ENOMEM; goto fail; } } if (i) { mop[0] = mop_len -= num; /* Move any stragglers down */ for (j = i - num; j < mop_len;) mop[++j] = mop[++i]; } else { txn->mt_next_pgno = pgno + num; } if (env->me_flags & MDBX_PAGEPERTURB) memset(np, 0x71 /* 'q', 113 */, env->me_psize * num); VALGRIND_MAKE_MEM_UNDEFINED(np, env->me_psize * num); np->mp_pgno = pgno; np->mp_leaf2_ksize = 0; np->mp_flags = 0; np->mp_pages = num; mdbx_page_dirty(txn, np); *mp = np; return MDB_SUCCESS; } /** Copy the used portions of a non-overflow page. * @param[in] dst page to copy into * @param[in] src page to copy from * @param[in] psize size of a page */ static void mdbx_page_copy(MDB_page *dst, MDB_page *src, unsigned psize) { enum { Align = sizeof(pgno_t) }; indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper - lower; /* If page isn't full, just copy the used portion. Adjust * alignment so memcpy may copy words instead of bytes. */ if ((unused &= -Align) && !IS_LEAF2(src)) { upper = (upper + PAGEBASE) & -Align; memcpy(dst, src, (lower + PAGEBASE + (Align - 1)) & -Align); memcpy((pgno_t *)((char *)dst + upper), (pgno_t *)((char *)src + upper), psize - upper); } else { memcpy(dst, src, psize - unused); } } /** Pull a page off the txn's spill list, if present. * If a page being referenced was spilled to disk in this txn, bring * it back and make it dirty/writable again. * @param[in] txn the transaction handle. * @param[in] mp the page being referenced. It must not be dirty. * @param[out] ret the writable page, if any. ret is unchanged if * mp wasn't spilled. */ static int mdbx_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret) { MDB_env *env = txn->mt_env; const MDB_txn *tx2; unsigned x; pgno_t pgno = mp->mp_pgno, pn = pgno << 1; for (tx2 = txn; tx2; tx2 = tx2->mt_parent) { if (!tx2->mt_spill_pgs) continue; x = mdbx_midl_search(tx2->mt_spill_pgs, pn); if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) { MDB_page *np; int num; if (txn->mt_dirty_room == 0) return MDB_TXN_FULL; if (IS_OVERFLOW(mp)) num = mp->mp_pages; else num = 1; if (env->me_flags & MDB_WRITEMAP) { np = mp; } else { np = mdbx_page_malloc(txn, num); if (unlikely(!np)) return ENOMEM; if (num > 1) memcpy(np, mp, num * env->me_psize); else mdbx_page_copy(np, mp, env->me_psize); } if (tx2 == txn) { /* If in current txn, this page is no longer spilled. * If it happens to be the last page, truncate the spill list. * Otherwise mark it as deleted by setting the LSB. */ if (x == txn->mt_spill_pgs[0]) txn->mt_spill_pgs[0]--; else txn->mt_spill_pgs[x] |= 1; } /* otherwise, if belonging to a parent txn, the * page remains spilled until child commits */ mdbx_page_dirty(txn, np); np->mp_flags |= P_DIRTY; *ret = np; break; } } return MDB_SUCCESS; } /** Touch a page: make it dirty and re-insert into tree with updated pgno. * Set #MDB_TXN_ERROR on failure. * @param[in] mc cursor pointing to the page to be touched * @return 0 on success, non-zero on failure. */ static int mdbx_page_touch(MDB_cursor *mc) { MDB_page *mp = mc->mc_pg[mc->mc_top], *np; MDB_txn *txn = mc->mc_txn; MDB_cursor *m2, *m3; pgno_t pgno; int rc; if (!F_ISSET(mp->mp_flags, P_DIRTY)) { if (txn->mt_flags & MDB_TXN_SPILLS) { np = NULL; rc = mdbx_page_unspill(txn, mp, &np); if (unlikely(rc)) goto fail; if (likely(np)) goto done; } if (unlikely((rc = mdbx_midl_need(&txn->mt_free_pgs, 1)) || (rc = mdbx_page_alloc(mc, 1, &np, MDBX_ALLOC_ALL)))) goto fail; pgno = np->mp_pgno; mdbx_debug("touched db %d page %zu -> %zu", DDBI(mc), mp->mp_pgno, pgno); mdbx_cassert(mc, mp->mp_pgno != pgno); mdbx_midl_xappend(txn->mt_free_pgs, mp->mp_pgno); /* Update the parent page, if any, to point to the new page */ if (mc->mc_top) { MDB_page *parent = mc->mc_pg[mc->mc_top - 1]; MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top - 1]); SETPGNO(node, pgno); } else { mc->mc_db->md_root = pgno; } } else if (txn->mt_parent && !IS_SUBP(mp)) { MDB_ID2 mid, *dl = txn->mt_u.dirty_list; pgno = mp->mp_pgno; /* If txn has a parent, make sure the page is in our * dirty list. */ if (dl[0].mid) { unsigned x = mdbx_mid2l_search(dl, pgno); if (x <= dl[0].mid && dl[x].mid == pgno) { if (unlikely(mp != dl[x].mptr)) { /* bad cursor? */ mc->mc_flags &= ~(C_INITIALIZED | C_EOF); txn->mt_flags |= MDB_TXN_ERROR; return MDB_PROBLEM; } return 0; } } mdbx_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX); /* No - copy it */ np = mdbx_page_malloc(txn, 1); if (unlikely(!np)) return ENOMEM; mid.mid = pgno; mid.mptr = np; rc = mdbx_mid2l_insert(dl, &mid); mdbx_cassert(mc, rc == 0); } else { return 0; } mdbx_page_copy(np, mp, txn->mt_env->me_psize); np->mp_pgno = pgno; np->mp_flags |= P_DIRTY; done: /* Adjust cursors pointing to mp */ mc->mc_pg[mc->mc_top] = np; m2 = txn->mt_cursors[mc->mc_dbi]; if (mc->mc_flags & C_SUB) { for (; m2; m2 = m2->mc_next) { m3 = &m2->mc_xcursor->mx_cursor; if (m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[mc->mc_top] == mp) m3->mc_pg[mc->mc_top] = np; } } else { for (; m2; m2 = m2->mc_next) { if (m2->mc_snum < mc->mc_snum) continue; if (m2 == mc) continue; if (m2->mc_pg[mc->mc_top] == mp) { m2->mc_pg[mc->mc_top] = np; if (XCURSOR_INITED(m2) && IS_LEAF(np)) XCURSOR_REFRESH(m2, np, m2->mc_ki[mc->mc_top]); } } } return 0; fail: txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdbx_env_sync(MDB_env *env, int force) { int rc; pthread_mutex_t *mutex; MDB_meta *head; unsigned flags; if (unlikely(!env)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!env->me_txns)) return MDB_PANIC; flags = env->me_flags & ~MDB_NOMETASYNC; if (unlikely(flags & (MDB_RDONLY | MDB_FATAL_ERROR))) return EACCES; head = mdbx_meta_head_r(env); if (!META_IS_WEAK(head) && env->me_sync_pending == 0 && env->me_mapsize == head->mm_mapsize) /* LY: nothing to do */ return MDB_SUCCESS; if (force || head->mm_mapsize != env->me_mapsize || (env->me_sync_threshold && env->me_sync_pending >= env->me_sync_threshold)) flags &= MDB_WRITEMAP; /* LY: early sync before acquiring the mutex to reduce writer's latency */ if (env->me_sync_pending > env->me_psize * 16 && (flags & MDB_NOSYNC) == 0) { if (flags & MDB_WRITEMAP) { size_t used_size = env->me_psize * (head->mm_last_pg + 1); rc = msync(env->me_map, used_size, (flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC); } else { rc = fdatasync(env->me_fd); } if (unlikely(rc)) return errno; } mutex = MDB_MUTEX(env, w); rc = mdbx_mutex_lock(env, mutex); if (unlikely(rc)) return rc; /* LY: head may be changed while the mutex has been acquired. */ head = mdbx_meta_head_w(env); rc = MDB_SUCCESS; if (META_IS_WEAK(head) || env->me_sync_pending != 0 || env->me_mapsize != head->mm_mapsize) { MDB_meta meta = *head; rc = mdbx_env_sync0(env, flags, &meta); } mdbx_mutex_unlock(env, mutex); return rc; } /** Back up parent txn's cursors, then grab the originals for tracking */ static int mdbx_cursor_shadow(MDB_txn *src, MDB_txn *dst) { MDB_cursor *mc, *bk; MDB_xcursor *mx; size_t size; int i; for (i = src->mt_numdbs; --i >= 0;) { if ((mc = src->mt_cursors[i]) != NULL) { size = sizeof(MDB_cursor); if (mc->mc_xcursor) size += sizeof(MDB_xcursor); for (; mc; mc = bk->mc_next) { bk = malloc(size); if (unlikely(!bk)) return ENOMEM; *bk = *mc; mc->mc_backup = bk; mc->mc_db = &dst->mt_dbs[i]; /* Kill pointers into src to reduce abuse: The * user may not use mc until dst ends. But we need a valid * txn pointer here for cursor fixups to keep working. */ mc->mc_txn = dst; mc->mc_dbflag = &dst->mt_dbflags[i]; if ((mx = mc->mc_xcursor) != NULL) { *(MDB_xcursor *)(bk + 1) = *mx; mx->mx_cursor.mc_txn = dst; } mc->mc_next = dst->mt_cursors[i]; dst->mt_cursors[i] = mc; } } } return MDB_SUCCESS; } /** Close this write txn's cursors, give parent txn's cursors back to parent. * @param[in] txn the transaction handle. * @param[in] merge true to keep changes to parent cursors, false to revert. * @return 0 on success, non-zero on failure. */ static void mdbx_cursors_eot(MDB_txn *txn, unsigned merge) { MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk; MDB_xcursor *mx; int i; for (i = txn->mt_numdbs; --i >= 0;) { for (mc = cursors[i]; mc; mc = next) { unsigned stage = mc->mc_signature; mdbx_ensure(NULL, stage == MDBX_MC_SIGNATURE || stage == MDBX_MC_WAIT4EOT); next = mc->mc_next; if ((bk = mc->mc_backup) != NULL) { if (merge) { /* Commit changes to parent txn */ mc->mc_next = bk->mc_next; mc->mc_backup = bk->mc_backup; mc->mc_txn = bk->mc_txn; mc->mc_db = bk->mc_db; mc->mc_dbflag = bk->mc_dbflag; if ((mx = mc->mc_xcursor) != NULL) mx->mx_cursor.mc_txn = bk->mc_txn; } else { /* Abort nested txn */ *mc = *bk; if ((mx = mc->mc_xcursor) != NULL) *mx = *(MDB_xcursor *)(bk + 1); } #if MDBX_MODE_ENABLED bk->mc_signature = 0; free(bk); } if (stage == MDBX_MC_WAIT4EOT) { mc->mc_signature = 0; free(mc); } else { mc->mc_signature = MDBX_MC_READY4CLOSE; mc->mc_flags = 0 /* reset C_UNTRACK */; } #else mc = bk; } /* Only malloced cursors are permanently tracked. */ mc->mc_signature = 0; free(mc); #endif } cursors[i] = NULL; } } /** Set or check a pid lock. Set returns 0 on success. * Check returns 0 if the process is certainly dead, nonzero if it may * be alive (the lock exists or an error happened so we do not know). */ static int mdbx_reader_pid(MDB_env *env, int op, pid_t pid) { for (;;) { int rc; struct flock lock_info; memset(&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_WRLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = pid; lock_info.l_len = 1; if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) { if (op == F_GETLK && lock_info.l_type != F_UNLCK) rc = -1; } else if ((rc = errno) == EINTR) { continue; } return rc; } } /** Common code for #mdbx_txn_begin() and #mdbx_txn_renew(). * @param[in] txn the transaction handle to initialize * @return 0 on success, non-zero on failure. */ static int mdbx_txn_renew0(MDB_txn *txn, unsigned flags) { MDB_env *env = txn->mt_env; unsigned i, nr; int rc, new_notls = 0; if (unlikely(env->me_pid != getpid())) { env->me_flags |= MDB_FATAL_ERROR; return MDB_PANIC; } if (flags & MDB_TXN_RDONLY) { MDBX_rthc *rthc = NULL; MDB_reader *r = NULL; txn->mt_flags = MDB_TXN_RDONLY; if (likely(env->me_flags & MDB_ENV_TXKEY)) { mdbx_assert(env, !(env->me_flags & MDB_NOTLS)); rthc = mdbx_rthc_get(env->me_txkey); if (unlikely(!rthc)) return ENOMEM; if (likely(rthc->rc_reader)) { r = rthc->rc_reader; mdbx_assert(env, r->mr_pid == env->me_pid); mdbx_assert(env, r->mr_tid == pthread_self()); } } else { mdbx_assert(env, env->me_flags & MDB_NOTLS); r = txn->mt_u.reader; } if (likely(r)) { if (unlikely(r->mr_pid != env->me_pid || r->mr_txnid != ~(txnid_t)0)) return MDB_BAD_RSLOT; } else { pid_t pid = env->me_pid; pthread_t tid = pthread_self(); pthread_mutex_t *rmutex = MDB_MUTEX(env, r); rc = mdbx_mutex_lock(env, rmutex); if (unlikely(rc != MDB_SUCCESS)) return rc; if (unlikely(!env->me_live_reader)) { rc = mdbx_reader_pid(env, F_SETLK, pid); if (unlikely(rc != MDB_SUCCESS)) { mdbx_mutex_unlock(env, rmutex); return rc; } env->me_live_reader = 1; } nr = env->me_txns->mti_numreaders; for (i = 0; i < nr; i++) if (env->me_txns->mti_readers[i].mr_pid == 0) break; if (unlikely(i == env->me_maxreaders)) { mdbx_mutex_unlock(env, rmutex); return MDB_READERS_FULL; } r = &env->me_txns->mti_readers[i]; /* Claim the reader slot, carefully since other code * uses the reader table un-mutexed: First reset the * slot, next publish it in mti_numreaders. After * that, it is safe for mdbx_env_close() to touch it. * When it will be closed, we can finally claim it. */ r->mr_pid = 0; r->mr_txnid = ~(txnid_t)0; r->mr_tid = tid; mdbx_coherent_barrier(); #ifdef __SANITIZE_THREAD__ pthread_mutex_lock(&tsan_mutex); #endif if (i == nr) env->me_txns->mti_numreaders = ++nr; if (env->me_close_readers < nr) env->me_close_readers = nr; r->mr_pid = pid; #ifdef __SANITIZE_THREAD__ pthread_mutex_unlock(&tsan_mutex); #endif mdbx_mutex_unlock(env, rmutex); new_notls = MDB_END_SLOT; if (likely(rthc)) { rthc->rc_reader = r; new_notls = 0; } } while ((env->me_flags & MDB_FATAL_ERROR) == 0) { MDB_meta *meta = mdbx_meta_head_r(txn->mt_env); txnid_t lead = meta->mm_txnid; r->mr_txnid = lead; mdbx_coherent_barrier(); txnid_t snap = txn->mt_env->me_txns->mti_txnid; /* LY: Retry on a race, ITS#7970. */ if (likely(lead == snap)) { txn->mt_txnid = lead; txn->mt_next_pgno = meta->mm_last_pg + 1; /* Copy the DB info and flags */ memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db)); #if MDBX_MODE_ENABLED txn->mt_canary = meta->mm_canary; #endif break; } } txn->mt_u.reader = r; txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */ } else { /* Not yet touching txn == env->me_txn0, it may be active */ rc = mdbx_mutex_lock(env, MDB_MUTEX(env, w)); if (unlikely(rc)) return rc; #ifdef __SANITIZE_THREAD__ pthread_mutex_lock(&tsan_mutex); #endif MDB_meta *meta = mdbx_meta_head_w(env); #if MDBX_MODE_ENABLED txn->mt_canary = meta->mm_canary; #endif txn->mt_txnid = meta->mm_txnid + 1; txn->mt_flags = flags; #ifdef __SANITIZE_THREAD__ pthread_mutex_unlock(&tsan_mutex); #endif #if MDB_DEBUG if (unlikely(txn->mt_txnid == mdbx_debug_edge)) { if (!mdbx_debug_logger) mdbx_runtime_flags |= MDBX_DBG_TRACE | MDBX_DBG_EXTRA | MDBX_DBG_AUDIT | MDBX_DBG_ASSERT; mdbx_debug_log(MDBX_DBG_EDGE, __FUNCTION__, __LINE__, "on/off edge (txn %zu)", txn->mt_txnid); } #endif txn->mt_child = NULL; txn->mt_loose_pgs = NULL; txn->mt_loose_count = 0; txn->mt_dirty_room = MDB_IDL_UM_MAX; txn->mt_u.dirty_list = env->me_dirty_list; txn->mt_u.dirty_list[0].mid = 0; txn->mt_free_pgs = env->me_free_pgs; txn->mt_free_pgs[0] = 0; txn->mt_spill_pgs = NULL; if (txn->mt_lifo_reclaimed) txn->mt_lifo_reclaimed[0] = 0; env->me_txn = txn; memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned)); /* Copy the DB info and flags */ memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db)); /* Moved to here to avoid a data race in read TXNs */ txn->mt_next_pgno = meta->mm_last_pg + 1; } /* Setup db info */ txn->mt_numdbs = env->me_numdbs; for (i = CORE_DBS; i < txn->mt_numdbs; i++) { unsigned x = env->me_dbflags[i]; txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS; txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID | DB_USRVALID | DB_STALE : 0; } txn->mt_dbflags[MAIN_DBI] = DB_VALID | DB_USRVALID; txn->mt_dbflags[FREE_DBI] = DB_VALID; if (unlikely(env->me_flags & MDB_FATAL_ERROR)) { mdbx_debug("environment had fatal error, must shutdown!"); rc = MDB_PANIC; } else if (unlikely(env->me_maxpg < txn->mt_next_pgno)) { rc = MDB_MAP_RESIZED; } else { return MDB_SUCCESS; } mdbx_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN); return rc; } int mdbx_txn_renew(MDB_txn *txn) { int rc; if (unlikely(!txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY | MDB_TXN_FINISHED))) return EINVAL; rc = mdbx_txn_renew0(txn, MDB_TXN_RDONLY); if (rc == MDB_SUCCESS) { mdbx_debug("renew txn %zu%c %p on mdbenv %p, root page %zu", txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root); } return rc; } int mdbx_txn_begin(MDB_env *env, MDB_txn *parent, unsigned flags, MDB_txn **ret) { MDB_txn *txn; MDB_ntxn *ntxn; int rc, size, tsize; if (unlikely(!env || !ret)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(env->me_pid != getpid())) { env->me_flags |= MDB_FATAL_ERROR; return MDB_PANIC; } flags &= MDB_TXN_BEGIN_FLAGS; flags |= env->me_flags & MDB_WRITEMAP; if (unlikely(env->me_flags & MDB_RDONLY & ~flags)) /* write txn in RDONLY env */ return EACCES; if (parent) { if (unlikely(parent->mt_signature != MDBX_MT_SIGNATURE)) return EINVAL; /* Nested transactions: Max 1 child, write txns only, no writemap */ flags |= parent->mt_flags; if (unlikely(flags & (MDB_RDONLY | MDB_WRITEMAP | MDB_TXN_BLOCKED))) { return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN; } /* Child txns save MDB_pgstate and use own copy of cursors */ size = env->me_maxdbs * (sizeof(MDB_db) + sizeof(MDB_cursor *) + 1); size += tsize = sizeof(MDB_ntxn); } else if (flags & MDB_RDONLY) { size = env->me_maxdbs * (sizeof(MDB_db) + 1); size += tsize = sizeof(MDB_txn); } else { /* Reuse preallocated write txn. However, do not touch it until * mdbx_txn_renew0() succeeds, since it currently may be active. */ txn = env->me_txn0; goto renew; } if (unlikely((txn = calloc(1, size)) == NULL)) { mdbx_debug("calloc: %s", strerror(errno)); return ENOMEM; } txn->mt_dbxs = env->me_dbxs; /* static */ txn->mt_dbs = (MDB_db *)((char *)txn + tsize); txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs; txn->mt_flags = flags; txn->mt_env = env; if (parent) { unsigned i; txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs); txn->mt_dbiseqs = parent->mt_dbiseqs; txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2) * MDB_IDL_UM_SIZE); if (!txn->mt_u.dirty_list || !(txn->mt_free_pgs = mdbx_midl_alloc(MDB_IDL_UM_MAX))) { free(txn->mt_u.dirty_list); free(txn); return ENOMEM; } txn->mt_txnid = parent->mt_txnid; txn->mt_dirty_room = parent->mt_dirty_room; txn->mt_u.dirty_list[0].mid = 0; txn->mt_spill_pgs = NULL; txn->mt_next_pgno = parent->mt_next_pgno; parent->mt_flags |= MDB_TXN_HAS_CHILD; parent->mt_child = txn; txn->mt_parent = parent; txn->mt_numdbs = parent->mt_numdbs; memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db)); /* Copy parent's mt_dbflags, but clear DB_NEW */ for (i = 0; i < txn->mt_numdbs; i++) txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW; rc = 0; ntxn = (MDB_ntxn *)txn; ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */ if (env->me_pghead) { size = MDB_IDL_SIZEOF(env->me_pghead); env->me_pghead = mdbx_midl_alloc(env->me_pghead[0]); if (likely(env->me_pghead)) memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size); else rc = ENOMEM; } if (likely(!rc)) rc = mdbx_cursor_shadow(parent, txn); if (unlikely(rc)) mdbx_txn_end(txn, MDB_END_FAIL_BEGINCHILD); } else { /* MDB_RDONLY */ txn->mt_dbiseqs = env->me_dbiseqs; renew: rc = mdbx_txn_renew0(txn, flags); } if (unlikely(rc)) { if (txn != env->me_txn0) free(txn); } else { txn->mt_signature = MDBX_MT_SIGNATURE; *ret = txn; mdbx_debug("begin txn %zu%c %p on mdbenv %p, root page %zu", txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w', (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root); } return rc; } MDB_env *mdbx_txn_env(MDB_txn *txn) { if (unlikely(!txn || txn->mt_signature != MDBX_MT_SIGNATURE)) return NULL; return txn->mt_env; } size_t mdbx_txn_id(MDB_txn *txn) { if (unlikely(!txn || txn->mt_signature != MDBX_MT_SIGNATURE)) return 0; return txn->mt_txnid; } /** Export or close DBI handles opened in this txn. */ static void mdbx_dbis_update(MDB_txn *txn, int keep) { int i; MDB_dbi n = txn->mt_numdbs; MDB_env *env = txn->mt_env; unsigned char *tdbflags = txn->mt_dbflags; for (i = n; --i >= CORE_DBS;) { if (tdbflags[i] & DB_NEW) { if (keep) { env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID; } else { char *ptr = env->me_dbxs[i].md_name.mv_data; if (ptr) { env->me_dbxs[i].md_name.mv_data = NULL; env->me_dbxs[i].md_name.mv_size = 0; env->me_dbflags[i] = 0; env->me_dbiseqs[i]++; free(ptr); } } } } if (keep && env->me_numdbs < n) env->me_numdbs = n; } /** End a transaction, except successful commit of a nested transaction. * May be called twice for readonly txns: First reset it, then abort. * @param[in] txn the transaction handle to end * @param[in] mode why and how to end the transaction */ static int mdbx_txn_end(MDB_txn *txn, unsigned mode) { MDB_env *env = txn->mt_env; static const char *const names[] = MDB_END_NAMES; if (unlikely(txn->mt_env->me_pid != getpid())) { env->me_flags |= MDB_FATAL_ERROR; return MDB_PANIC; } /* Export or close DBI handles opened in this txn */ mdbx_dbis_update(txn, mode & MDB_END_UPDATE); mdbx_debug("%s txn %zu%c %p on mdbenv %p, root page %zu", names[mode & MDB_END_OPMASK], txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root); if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { if (txn->mt_u.reader) { #ifdef __SANITIZE_THREAD__ pthread_mutex_lock(&tsan_mutex); #endif txn->mt_u.reader->mr_txnid = ~(txnid_t)0; if (!(env->me_flags & MDB_NOTLS)) { txn->mt_u.reader = NULL; /* txn does not own reader */ } else if (mode & MDB_END_SLOT) { txn->mt_u.reader->mr_pid = 0; txn->mt_u.reader = NULL; } /* else txn owns the slot until it does MDB_END_SLOT */ #ifdef __SANITIZE_THREAD__ pthread_mutex_unlock(&tsan_mutex); #endif } mdbx_coherent_barrier(); txn->mt_numdbs = 0; /* prevent further DBI activity */ txn->mt_flags |= MDB_TXN_FINISHED; } else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) { pgno_t *pghead = env->me_pghead; if (!(mode & MDB_END_EOTDONE)) /* !(already closed cursors) */ mdbx_cursors_eot(txn, 0); if (!(env->me_flags & MDB_WRITEMAP)) { mdbx_dlist_free(txn); } if (txn->mt_lifo_reclaimed) { txn->mt_lifo_reclaimed[0] = 0; if (txn != env->me_txn0) { mdbx_midl_free(txn->mt_lifo_reclaimed); txn->mt_lifo_reclaimed = NULL; } } txn->mt_numdbs = 0; txn->mt_flags = MDB_TXN_FINISHED; if (!txn->mt_parent) { mdbx_midl_shrink(&txn->mt_free_pgs); env->me_free_pgs = txn->mt_free_pgs; /* me_pgstate: */ env->me_pghead = NULL; env->me_pglast = 0; env->me_txn = NULL; mode = 0; /* txn == env->me_txn0, do not free() it */ /* The writer mutex was locked in mdbx_txn_begin. */ mdbx_mutex_unlock(env, MDB_MUTEX(env, w)); } else { txn->mt_parent->mt_child = NULL; txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD; env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate; mdbx_midl_free(txn->mt_free_pgs); mdbx_midl_free(txn->mt_spill_pgs); free(txn->mt_u.dirty_list); } mdbx_midl_free(pghead); } if (mode & MDB_END_FREE) { txn->mt_signature = 0; free(txn); } return MDB_SUCCESS; } int mdbx_txn_reset(MDB_txn *txn) { if (unlikely(!txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; /* This call is only valid for read-only txns */ if (unlikely(!(txn->mt_flags & MDB_TXN_RDONLY))) return EINVAL; #if MDBX_MODE_ENABLED /* LY: don't close DBI-handles in MDBX mode */ return mdbx_txn_end(txn, MDB_END_RESET | MDB_END_UPDATE); #else return mdbx_txn_end(txn, MDB_END_RESET); #endif /* MDBX_MODE_ENABLED */ } int mdbx_txn_abort(MDB_txn *txn) { if (unlikely(!txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; #if MDBX_MODE_ENABLED if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) /* LY: don't close DBI-handles in MDBX mode */ return mdbx_txn_end(txn, MDB_END_ABORT | MDB_END_UPDATE | MDB_END_SLOT | MDB_END_FREE); #endif /* MDBX_MODE_ENABLED */ if (txn->mt_child) mdbx_txn_abort(txn->mt_child); return mdbx_txn_end(txn, MDB_END_ABORT | MDB_END_SLOT | MDB_END_FREE); } static MDBX_INLINE int mdbx_backlog_size(MDB_txn *txn) { int reclaimed = txn->mt_env->me_pghead ? txn->mt_env->me_pghead[0] : 0; return reclaimed + txn->mt_loose_count; } /* LY: Prepare a backlog of pages to modify FreeDB itself, * while reclaiming is prohibited. It should be enough to prevent search * in mdbx_page_alloc() during a deleting, when freeDB tree is unbalanced. */ static int mdbx_prep_backlog(MDB_txn *txn, MDB_cursor *mc) { /* LY: extra page(s) for b-tree rebalancing */ const int extra = (txn->mt_env->me_flags & MDBX_LIFORECLAIM) ? 2 : 1; if (mdbx_backlog_size(txn) < mc->mc_db->md_depth + extra) { int rc = mdbx_cursor_touch(mc); if (unlikely(rc)) return rc; while (unlikely(mdbx_backlog_size(txn) < extra)) { rc = mdbx_page_alloc(mc, 1, NULL, MDBX_ALLOC_GC); if (unlikely(rc)) { if (unlikely(rc != MDB_NOTFOUND)) return rc; break; } } } return MDB_SUCCESS; } /** Save the freelist as of this transaction to the freeDB. * This changes the freelist. Keep trying until it stabilizes. */ static int mdbx_freelist_save(MDB_txn *txn) { /* env->me_pghead[] can grow and shrink during this call. * env->me_pglast and txn->mt_free_pgs[] can only grow. * Page numbers cannot disappear from txn->mt_free_pgs[]. */ MDB_cursor mc; MDB_env *env = txn->mt_env; int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1; txnid_t pglast = 0, head_id = 0; pgno_t freecnt = 0, *free_pgs, *mop; ssize_t head_room = 0, total_room = 0, mop_len, clean_limit; unsigned cleanup_idx = 0, refill_idx = 0; const int lifo = (env->me_flags & MDBX_LIFORECLAIM) != 0; mdbx_cursor_init(&mc, txn, FREE_DBI, NULL); /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */ clean_limit = (env->me_flags & (MDB_NOMEMINIT | MDB_WRITEMAP)) ? SSIZE_MAX : maxfree_1pg; again: for (;;) { /* Come back here after each Put() in case freelist changed */ MDB_val key, data; pgno_t *pgs; ssize_t j; if (!lifo) { /* If using records from freeDB which we have not yet * deleted, delete them and any we reserved for me_pghead. */ while (pglast < env->me_pglast) { rc = mdbx_cursor_first(&mc, &key, NULL); if (unlikely(rc)) goto bailout; rc = mdbx_prep_backlog(txn, &mc); if (unlikely(rc)) goto bailout; pglast = head_id = *(txnid_t *)key.mv_data; total_room = head_room = 0; more = 1; mdbx_tassert(txn, pglast <= env->me_pglast); mc.mc_flags |= C_RECLAIMING; rc = mdbx_cursor_del(&mc, 0); mc.mc_flags &= ~C_RECLAIMING; if (unlikely(rc)) goto bailout; } } else if (txn->mt_lifo_reclaimed) { /* LY: cleanup reclaimed records. */ while (cleanup_idx < txn->mt_lifo_reclaimed[0]) { pglast = txn->mt_lifo_reclaimed[++cleanup_idx]; key.mv_data = &pglast; key.mv_size = sizeof(pglast); rc = mdbx_cursor_get(&mc, &key, NULL, MDB_SET); if (likely(rc != MDB_NOTFOUND)) { if (unlikely(rc)) goto bailout; rc = mdbx_prep_backlog(txn, &mc); if (unlikely(rc)) goto bailout; mc.mc_flags |= C_RECLAIMING; rc = mdbx_cursor_del(&mc, 0); mc.mc_flags &= ~C_RECLAIMING; if (unlikely(rc)) goto bailout; } } } if (unlikely(!env->me_pghead) && txn->mt_loose_pgs) { /* Put loose page numbers in mt_free_pgs, since * we may be unable to return them to me_pghead. */ MDB_page *mp = txn->mt_loose_pgs; if (unlikely((rc = mdbx_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)) return rc; for (; mp; mp = NEXT_LOOSE_PAGE(mp)) mdbx_midl_xappend(txn->mt_free_pgs, mp->mp_pgno); txn->mt_loose_pgs = NULL; txn->mt_loose_count = 0; } /* Save the IDL of pages freed by this txn, to a single record */ if (freecnt < txn->mt_free_pgs[0]) { if (unlikely(!freecnt)) { /* Make sure last page of freeDB is touched and on freelist */ rc = mdbx_page_search(&mc, NULL, MDB_PS_LAST | MDB_PS_MODIFY); if (unlikely(rc && rc != MDB_NOTFOUND)) goto bailout; } free_pgs = txn->mt_free_pgs; /* Write to last page of freeDB */ key.mv_size = sizeof(txn->mt_txnid); key.mv_data = &txn->mt_txnid; do { freecnt = free_pgs[0]; data.mv_size = MDB_IDL_SIZEOF(free_pgs); rc = mdbx_cursor_put(&mc, &key, &data, MDB_RESERVE); if (unlikely(rc)) goto bailout; /* Retry if mt_free_pgs[] grew during the Put() */ free_pgs = txn->mt_free_pgs; } while (freecnt < free_pgs[0]); mdbx_midl_sort(free_pgs); memcpy(data.mv_data, free_pgs, data.mv_size); if (mdbx_debug_enabled(MDBX_DBG_EXTRA)) { unsigned i = free_pgs[0]; mdbx_debug_extra("IDL write txn %zu root %zu num %u, IDL", txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i); for (; i; i--) mdbx_debug_extra_print(" %zu", free_pgs[i]); mdbx_debug_extra_print("\n"); } continue; } mop = env->me_pghead; mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count; if (mop_len && refill_idx == 0) refill_idx = 1; /* Reserve records for me_pghead[]. Split it if multi-page, * to avoid searching freeDB for a page range. Use keys in * range [1,me_pglast]: Smaller than txnid of oldest reader. */ if (total_room >= mop_len) { if (total_room == mop_len || --more < 0) break; } else if (head_room >= maxfree_1pg && head_id > 1) { /* Keep current record (overflow page), add a new one */ head_id--; refill_idx++; head_room = 0; } if (lifo) { if (refill_idx > (txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0)) { /* LY: need just a txn-id for save page list. */ rc = mdbx_page_alloc(&mc, 0, NULL, MDBX_ALLOC_GC | MDBX_ALLOC_KICK); if (likely(rc == 0)) /* LY: ok, reclaimed from freedb. */ continue; if (unlikely(rc != MDB_NOTFOUND)) /* LY: other troubles... */ goto bailout; /* LY: freedb is empty, will look any free txn-id in high2low order. */ if (unlikely(env->me_pglast < 1)) { /* LY: not any txn in the past of freedb. */ rc = MDB_MAP_FULL; goto bailout; } if (unlikely(!txn->mt_lifo_reclaimed)) { txn->mt_lifo_reclaimed = mdbx_midl_alloc(env->me_maxfree_1pg); if (unlikely(!txn->mt_lifo_reclaimed)) { rc = ENOMEM; goto bailout; } } /* LY: append the list. */ rc = mdbx_midl_append(&txn->mt_lifo_reclaimed, env->me_pglast - 1); if (unlikely(rc)) goto bailout; --env->me_pglast; /* LY: note that freeDB cleanup is not needed. */ ++cleanup_idx; } head_id = txn->mt_lifo_reclaimed[refill_idx]; } /* (Re)write {key = head_id, IDL length = head_room} */ total_room -= head_room; head_room = mop_len - total_room; if (head_room > maxfree_1pg && head_id > 1) { /* Overflow multi-page for part of me_pghead */ head_room /= head_id; /* amortize page sizes */ head_room += maxfree_1pg - head_room % (maxfree_1pg + 1); } else if (head_room < 0) { /* Rare case, not bothering to delete this record */ head_room = 0; continue; } key.mv_size = sizeof(head_id); key.mv_data = &head_id; data.mv_size = (head_room + 1) * sizeof(pgno_t); rc = mdbx_cursor_put(&mc, &key, &data, MDB_RESERVE); if (unlikely(rc)) goto bailout; /* IDL is initially empty, zero out at least the length */ pgs = (pgno_t *)data.mv_data; j = head_room > clean_limit ? head_room : 0; do { pgs[j] = 0; } while (--j >= 0); total_room += head_room; } mdbx_tassert(txn, cleanup_idx == (txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0)); /* Return loose page numbers to me_pghead, though usually none are * left at this point. The pages themselves remain in dirty_list. */ if (txn->mt_loose_pgs) { MDB_page *mp = txn->mt_loose_pgs; unsigned count = txn->mt_loose_count; MDB_IDL loose; /* Room for loose pages + temp IDL with same */ if ((rc = mdbx_midl_need(&env->me_pghead, 2 * count + 1)) != 0) goto bailout; mop = env->me_pghead; loose = mop + MDB_IDL_ALLOCLEN(mop) - count; for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp)) loose[++count] = mp->mp_pgno; loose[0] = count; mdbx_midl_sort(loose); mdbx_midl_xmerge(mop, loose); txn->mt_loose_pgs = NULL; txn->mt_loose_count = 0; mop_len = mop[0]; } /* Fill in the reserved me_pghead records */ rc = MDB_SUCCESS; if (mop_len) { MDB_val key, data; mop += mop_len; if (!lifo) { rc = mdbx_cursor_first(&mc, &key, &data); if (unlikely(rc)) goto bailout; } for (;;) { txnid_t id; ssize_t len; MDB_ID save; if (!lifo) { id = *(txnid_t *)key.mv_data; mdbx_tassert(txn, id <= env->me_pglast); } else { mdbx_tassert(txn, refill_idx > 0 && refill_idx <= txn->mt_lifo_reclaimed[0]); id = txn->mt_lifo_reclaimed[refill_idx--]; key.mv_data = &id; key.mv_size = sizeof(id); rc = mdbx_cursor_get(&mc, &key, &data, MDB_SET); if (unlikely(rc)) goto bailout; } mdbx_tassert( txn, cleanup_idx == (txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0)); len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1; mdbx_tassert(txn, len >= 0); if (len > mop_len) len = mop_len; data.mv_size = (len + 1) * sizeof(MDB_ID); key.mv_data = &id; key.mv_size = sizeof(id); data.mv_data = mop -= len; save = mop[0]; mop[0] = len; rc = mdbx_cursor_put(&mc, &key, &data, MDB_CURRENT); mdbx_tassert( txn, cleanup_idx == (txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0)); mop[0] = save; if (unlikely(rc || (mop_len -= len) == 0)) goto bailout; if (!lifo) { rc = mdbx_cursor_next(&mc, &key, &data, MDB_NEXT); if (unlikely(rc)) goto bailout; } } } bailout: if (txn->mt_lifo_reclaimed) { mdbx_tassert(txn, rc || cleanup_idx == txn->mt_lifo_reclaimed[0]); if (rc == 0 && cleanup_idx != txn->mt_lifo_reclaimed[0]) { mdbx_tassert(txn, cleanup_idx < txn->mt_lifo_reclaimed[0]); /* LY: zeroed cleanup_idx to force cleanup & refill created freeDB * records. */ cleanup_idx = 0; /* LY: restart filling */ refill_idx = total_room = head_room = 0; more = 1; goto again; } txn->mt_lifo_reclaimed[0] = 0; if (txn != env->me_txn0) { mdbx_midl_free(txn->mt_lifo_reclaimed); txn->mt_lifo_reclaimed = NULL; } } return rc; } /** Flush (some) dirty pages to the map, after clearing their dirty flag. * @param[in] txn the transaction that's being committed * @param[in] keep number of initial pages in dirty_list to keep dirty. * @return 0 on success, non-zero on failure. */ static int mdbx_page_flush(MDB_txn *txn, int keep) { MDB_env *env = txn->mt_env; MDB_ID2L dl = txn->mt_u.dirty_list; unsigned psize = env->me_psize, j; int i, pagecount = dl[0].mid, rc; size_t size = 0, pos = 0; pgno_t pgno = 0; MDB_page *dp = NULL; struct iovec iov[MDB_COMMIT_PAGES]; ssize_t wpos = 0, wsize = 0, wres; size_t next_pos = 1; /* impossible pos, so pos != next_pos */ int n = 0; j = i = keep; if (env->me_flags & MDB_WRITEMAP) { /* Clear dirty flags */ while (++i <= pagecount) { dp = dl[i].mptr; /* Don't flush this page yet */ if (dp->mp_flags & (P_LOOSE | P_KEEP)) { dp->mp_flags &= ~P_KEEP; dl[++j] = dl[i]; continue; } dp->mp_flags &= ~P_DIRTY; env->me_sync_pending += IS_OVERFLOW(dp) ? psize * dp->mp_pages : psize; } goto done; } /* Write the pages */ for (;;) { if (++i <= pagecount) { dp = dl[i].mptr; /* Don't flush this page yet */ if (dp->mp_flags & (P_LOOSE | P_KEEP)) { dp->mp_flags &= ~P_KEEP; dl[i].mid = 0; continue; } pgno = dl[i].mid; /* clear dirty flag */ dp->mp_flags &= ~P_DIRTY; pos = pgno * psize; size = psize; if (IS_OVERFLOW(dp)) size *= dp->mp_pages; env->me_sync_pending += size; } /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */ if (pos != next_pos || n == MDB_COMMIT_PAGES || wsize + size > MAX_WRITE) { if (n) { retry: /* Write previous page(s) */ wres = pwritev(env->me_fd, iov, n, wpos); if (unlikely(wres != wsize)) { if (wres < 0) { rc = errno; if (rc == EINTR) goto retry; mdbx_debug("Write error: %s", strerror(rc)); } else { rc = EIO; /* TODO: Use which error code? */ mdbx_debug("short write, filesystem full?"); } return rc; } n = 0; } if (i > pagecount) break; wpos = pos; wsize = 0; } mdbx_debug("committing page %zu", pgno); next_pos = pos + size; iov[n].iov_len = size; iov[n].iov_base = (char *)dp; wsize += size; n++; } mdbx_invalidate_cache(env->me_map, txn->mt_next_pgno * env->me_psize); for (i = keep; ++i <= pagecount;) { dp = dl[i].mptr; /* This is a page we skipped above */ if (!dl[i].mid) { dl[++j] = dl[i]; dl[j].mid = dp->mp_pgno; continue; } mdbx_dpage_free(env, dp); } done: i--; txn->mt_dirty_room += i - j; dl[0].mid = j; return MDB_SUCCESS; } int mdbx_txn_commit(MDB_txn *txn) { int rc; unsigned i; if (unlikely(txn == NULL)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; MDB_env *env = txn->mt_env; if (unlikely(env->me_pid != getpid())) { env->me_flags |= MDB_FATAL_ERROR; return MDB_PANIC; } if (txn->mt_child) { rc = mdbx_txn_commit(txn->mt_child); txn->mt_child = NULL; if (unlikely(rc != MDB_SUCCESS)) goto fail; } /* mdbx_txn_end() mode for a commit which writes nothing */ unsigned end_mode = MDB_END_EMPTY_COMMIT | MDB_END_UPDATE | MDB_END_SLOT | MDB_END_FREE; if (unlikely(F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))) goto done; if (unlikely(txn->mt_flags & (MDB_TXN_FINISHED | MDB_TXN_ERROR))) { mdbx_debug("error flag is set, can't commit"); if (txn->mt_parent) txn->mt_parent->mt_flags |= MDB_TXN_ERROR; rc = MDB_BAD_TXN; goto fail; } if (txn->mt_parent) { MDB_txn *parent = txn->mt_parent; MDB_page **lp; MDB_ID2L dst, src; MDB_IDL pspill; unsigned x, y, len, ps_len; /* Append our reclaim list to parent's */ if (txn->mt_lifo_reclaimed) { if (parent->mt_lifo_reclaimed) { rc = mdbx_midl_append_list(&parent->mt_lifo_reclaimed, txn->mt_lifo_reclaimed); if (unlikely(rc != MDB_SUCCESS)) goto fail; mdbx_midl_free(txn->mt_lifo_reclaimed); } else parent->mt_lifo_reclaimed = txn->mt_lifo_reclaimed; txn->mt_lifo_reclaimed = NULL; } /* Append our free list to parent's */ rc = mdbx_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs); if (unlikely(rc != MDB_SUCCESS)) goto fail; mdbx_midl_free(txn->mt_free_pgs); /* Failures after this must either undo the changes * to the parent or set MDB_TXN_ERROR in the parent. */ parent->mt_next_pgno = txn->mt_next_pgno; parent->mt_flags = txn->mt_flags; /* Merge our cursors into parent's and close them */ mdbx_cursors_eot(txn, 1); /* Update parent's DB table. */ memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db)); parent->mt_numdbs = txn->mt_numdbs; parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI]; parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI]; for (i = CORE_DBS; i < txn->mt_numdbs; i++) { /* preserve parent's DB_NEW status */ x = parent->mt_dbflags[i] & DB_NEW; parent->mt_dbflags[i] = txn->mt_dbflags[i] | x; } dst = parent->mt_u.dirty_list; src = txn->mt_u.dirty_list; /* Remove anything in our dirty list from parent's spill list */ if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) { x = y = ps_len; pspill[0] = (pgno_t)-1; /* Mark our dirty pages as deleted in parent spill list */ for (i = 0, len = src[0].mid; ++i <= len;) { MDB_ID pn = src[i].mid << 1; while (pn > pspill[x]) x--; if (pn == pspill[x]) { pspill[x] = 1; y = --x; } } /* Squash deleted pagenums if we deleted any */ for (x = y; ++x <= ps_len;) if (!(pspill[x] & 1)) pspill[++y] = pspill[x]; pspill[0] = y; } /* Remove anything in our spill list from parent's dirty list */ if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) { for (i = 1; i <= txn->mt_spill_pgs[0]; i++) { MDB_ID pn = txn->mt_spill_pgs[i]; if (pn & 1) continue; /* deleted spillpg */ pn >>= 1; y = mdbx_mid2l_search(dst, pn); if (y <= dst[0].mid && dst[y].mid == pn) { free(dst[y].mptr); while (y < dst[0].mid) { dst[y] = dst[y + 1]; y++; } dst[0].mid--; } } } /* Find len = length of merging our dirty list with parent's */ x = dst[0].mid; dst[0].mid = 0; /* simplify loops */ if (parent->mt_parent) { len = x + src[0].mid; y = mdbx_mid2l_search(src, dst[x].mid + 1) - 1; for (i = x; y && i; y--) { pgno_t yp = src[y].mid; while (yp < dst[i].mid) i--; if (yp == dst[i].mid) { i--; len--; } } } else { /* Simplify the above for single-ancestor case */ len = MDB_IDL_UM_MAX - txn->mt_dirty_room; } /* Merge our dirty list with parent's */ y = src[0].mid; for (i = len; y; dst[i--] = src[y--]) { pgno_t yp = src[y].mid; while (yp < dst[x].mid) dst[i--] = dst[x--]; if (yp == dst[x].mid) free(dst[x--].mptr); } mdbx_tassert(txn, i == x); dst[0].mid = len; free(txn->mt_u.dirty_list); parent->mt_dirty_room = txn->mt_dirty_room; if (txn->mt_spill_pgs) { if (parent->mt_spill_pgs) { /* TODO: Prevent failure here, so parent does not fail */ rc = mdbx_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs); if (unlikely(rc != MDB_SUCCESS)) parent->mt_flags |= MDB_TXN_ERROR; mdbx_midl_free(txn->mt_spill_pgs); mdbx_midl_sort(parent->mt_spill_pgs); } else { parent->mt_spill_pgs = txn->mt_spill_pgs; } } /* Append our loose page list to parent's */ for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp)) ; *lp = txn->mt_loose_pgs; parent->mt_loose_count += txn->mt_loose_count; parent->mt_child = NULL; mdbx_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead); txn->mt_signature = 0; free(txn); return rc; } if (unlikely(txn != env->me_txn)) { mdbx_debug("attempt to commit unknown transaction"); rc = EINVAL; goto fail; } mdbx_cursors_eot(txn, 0); end_mode |= MDB_END_EOTDONE; if (!txn->mt_u.dirty_list[0].mid && !(txn->mt_flags & (MDB_TXN_DIRTY | MDB_TXN_SPILLS))) goto done; mdbx_debug("committing txn %zu %p on mdbenv %p, root page %zu", txn->mt_txnid, (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root); /* Update DB root pointers */ if (txn->mt_numdbs > CORE_DBS) { MDB_cursor mc; MDB_dbi i; MDB_val data; data.mv_size = sizeof(MDB_db); mdbx_cursor_init(&mc, txn, MAIN_DBI, NULL); for (i = CORE_DBS; i < txn->mt_numdbs; i++) { if (txn->mt_dbflags[i] & DB_DIRTY) { if (unlikely(TXN_DBI_CHANGED(txn, i))) { rc = MDB_BAD_DBI; goto fail; } data.mv_data = &txn->mt_dbs[i]; rc = mdbx_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, F_SUBDATA); if (unlikely(rc != MDB_SUCCESS)) goto fail; } } } rc = mdbx_freelist_save(txn); if (unlikely(rc != MDB_SUCCESS)) goto fail; mdbx_midl_free(env->me_pghead); env->me_pghead = NULL; mdbx_midl_shrink(&txn->mt_free_pgs); if (mdbx_audit_enabled()) mdbx_audit(txn); rc = mdbx_page_flush(txn, 0); if (likely(rc == MDB_SUCCESS)) { MDB_meta meta; meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI]; meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI]; meta.mm_last_pg = txn->mt_next_pgno - 1; meta.mm_txnid = txn->mt_txnid; #if MDBX_MODE_ENABLED meta.mm_canary = txn->mt_canary; #endif rc = mdbx_env_sync0(env, env->me_flags | txn->mt_flags, &meta); } if (unlikely(rc != MDB_SUCCESS)) goto fail; end_mode = MDB_END_COMMITTED | MDB_END_UPDATE | MDB_END_EOTDONE; done: return mdbx_txn_end(txn, end_mode); fail: mdbx_txn_abort(txn); return rc; } /** Read the environment parameters of a DB environment before * mapping it into memory. * @param[in] env the environment handle * @param[out] meta address of where to store the meta information * @return 0 on success, non-zero on failure. */ static int __cold mdbx_env_read_header(MDB_env *env, MDB_meta *meta) { MDB_metabuf pbuf; MDB_page *p; MDB_meta *m; int i, rc, off; enum { Size = sizeof(pbuf) }; /* We don't know the page size yet, so use a minimum value. * Read both meta pages so we can use the latest one. */ meta->mm_datasync_sign = MDB_DATASIGN_WEAK; meta->mm_txnid = 0; for (i = off = 0; i < NUM_METAS; i++, off += meta->mm_psize) { rc = pread(env->me_fd, &pbuf, Size, off); if (rc != Size) { if (rc == 0 && off == 0) return ENOENT; rc = rc < 0 ? (int)errno : MDB_INVALID; mdbx_debug("read: %s", mdbx_strerror(rc)); return rc; } p = (MDB_page *)&pbuf; if (!F_ISSET(p->mp_flags, P_META)) { mdbx_debug("page %zu not a meta page", p->mp_pgno); return MDB_INVALID; } m = PAGEDATA(p); if (m->mm_magic != MDB_MAGIC) { mdbx_debug("meta has invalid magic"); return MDB_INVALID; } if (m->mm_version != MDB_DATA_VERSION) { mdbx_debug("database is version %u, expected version %u", m->mm_version, MDB_DATA_VERSION); return MDB_VERSION_MISMATCH; } if (m->mm_datasync_sign > MDB_DATASIGN_WEAK && m->mm_datasync_sign != mdbx_meta_sign(m)) continue; if (mdbx_meta_lt(meta, m)) *meta = *m; } if (meta->mm_datasync_sign == MDB_DATASIGN_WEAK) /* LY: Both meta-pages are weak. */ return MDB_CORRUPTED; return MDB_SUCCESS; } /** Fill in most of the zeroed #MDB_meta for an empty database environment */ static void __cold mdbx_env_init_meta0(MDB_env *env, MDB_meta *meta) { meta->mm_magic = MDB_MAGIC; meta->mm_version = MDB_DATA_VERSION; meta->mm_mapsize = env->me_mapsize; meta->mm_psize = env->me_psize; meta->mm_last_pg = NUM_METAS - 1; meta->mm_flags = env->me_flags & 0xffff; meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */ meta->mm_dbs[FREE_DBI].md_root = P_INVALID; meta->mm_dbs[MAIN_DBI].md_root = P_INVALID; meta->mm_datasync_sign = mdbx_meta_sign(meta); } /** Write the environment parameters of a freshly created DB environment. * @param[in] env the environment handle * @param[in] meta the #MDB_meta to write * @return 0 on success, non-zero on failure. */ static int __cold mdbx_env_init_meta(MDB_env *env, MDB_meta *meta) { MDB_page *p, *q; int rc; unsigned psize; int len; mdbx_debug("writing new meta page"); psize = env->me_psize; p = calloc(NUM_METAS, psize); if (!p) return ENOMEM; p->mp_pgno = 0; p->mp_flags = P_META; *(MDB_meta *)PAGEDATA(p) = *meta; q = (MDB_page *)((char *)p + psize); q->mp_pgno = 1; q->mp_flags = P_META; *(MDB_meta *)PAGEDATA(q) = *meta; do len = pwrite(env->me_fd, p, psize * NUM_METAS, 0); while (len == -1 && errno == EINTR); if (len < 0) rc = errno; else if ((unsigned)len == psize * NUM_METAS) rc = MDB_SUCCESS; else rc = ENOSPC; free(p); return rc; } static int mdbx_env_sync0(MDB_env *env, unsigned flags, MDB_meta *pending) { int rc; MDB_meta *head = mdbx_meta_head_w(env); size_t prev_mapsize = head->mm_mapsize; size_t used_size = env->me_psize * (pending->mm_last_pg + 1); mdbx_assert(env, pending != METAPAGE_1(env) && pending != METAPAGE_2(env)); mdbx_assert(env, (env->me_flags & (MDB_RDONLY | MDB_FATAL_ERROR)) == 0); mdbx_assert(env, META_IS_WEAK(head) || env->me_sync_pending != 0 || env->me_mapsize != prev_mapsize); pending->mm_mapsize = env->me_mapsize; mdbx_assert(env, pending->mm_mapsize >= used_size); if (unlikely(pending->mm_mapsize != prev_mapsize)) { if (pending->mm_mapsize < prev_mapsize) { /* LY: currently this can't happen, but force full-sync. */ flags &= MDB_WRITEMAP; } else { /* Persist any increases of mapsize config */ } } if (env->me_sync_threshold && env->me_sync_pending >= env->me_sync_threshold) flags &= MDB_WRITEMAP; /* LY: step#1 - sync previously written/updated data-pages */ if (env->me_sync_pending && (flags & MDB_NOSYNC) == 0) { if (env->me_flags & MDB_WRITEMAP) { int mode = (flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC; if (unlikely(msync(env->me_map, used_size, mode))) { rc = errno; /* LY: msync() should never return EINTR */ goto fail; } if ((flags & MDB_MAPASYNC) == 0) env->me_sync_pending = 0; } else { int (*flush)(int fd) = fdatasync; if (unlikely(prev_mapsize != pending->mm_mapsize)) { /* LY: It is no reason to use fdatasync() here, even in case * no such bug in a kernel. Because "no-bug" mean that a kernel * internally do nearly the same, e.g. fdatasync() == fsync() * when no-kernel-bug and file size was changed. * * So, this code is always safe and without appreciable * performance degradation. * * For more info about of a corresponding fdatasync() bug * see http://www.spinics.net/lists/linux-ext4/msg33714.html */ flush = fsync; } while (unlikely(flush(env->me_fd) < 0)) { rc = errno; if (rc != EINTR) goto fail; } env->me_sync_pending = 0; } } /* LY: step#2 - update meta-page. */ if (env->me_sync_pending == 0) { pending->mm_datasync_sign = mdbx_meta_sign(pending); } else { pending->mm_datasync_sign = (flags & MDBX_UTTERLY_NOSYNC) == MDBX_UTTERLY_NOSYNC ? MDB_DATASIGN_NONE : MDB_DATASIGN_WEAK; } volatile MDB_meta *target = (pending->mm_txnid == head->mm_txnid || META_IS_WEAK(head)) ? head : mdbx_env_meta_flipflop(env, head); off_t offset = (char *)target - env->me_map; MDB_meta *stay = mdbx_env_meta_flipflop(env, (MDB_meta *)target); mdbx_debug( "writing meta %d (%s, was %zu/%s, stay %s %zu/%s), root %zu, " "txn_id %zu, %s", offset >= env->me_psize, target == head ? "head" : "tail", target->mm_txnid, META_IS_WEAK(target) ? "Weak" : META_IS_STEADY(target) ? "Steady" : "Legacy", stay == head ? "head" : "tail", stay->mm_txnid, META_IS_WEAK(stay) ? "Weak" : META_IS_STEADY(stay) ? "Steady" : "Legacy", pending->mm_dbs[MAIN_DBI].md_root, pending->mm_txnid, META_IS_WEAK(pending) ? "Weak" : META_IS_STEADY(pending) ? "Steady" : "Legacy"); if (env->me_flags & MDB_WRITEMAP) { #ifdef __SANITIZE_THREAD__ pthread_mutex_lock(&tsan_mutex); #endif /* LY: 'invalidate' the meta, * but mdbx_meta_head_r() will be confused/retired in collision case. */ target->mm_datasync_sign = MDB_DATASIGN_WEAK; target->mm_txnid = 0; /* LY: update info */ target->mm_mapsize = pending->mm_mapsize; target->mm_dbs[FREE_DBI] = pending->mm_dbs[FREE_DBI]; target->mm_dbs[MAIN_DBI] = pending->mm_dbs[MAIN_DBI]; target->mm_last_pg = pending->mm_last_pg; #if MDBX_MODE_ENABLED target->mm_canary = pending->mm_canary; #endif /* LY: 'commit' the meta */ target->mm_txnid = pending->mm_txnid; target->mm_datasync_sign = pending->mm_datasync_sign; } else { pending->mm_magic = MDB_MAGIC; pending->mm_version = MDB_DATA_VERSION; pending->mm_address = head->mm_address; retry: rc = pwrite(env->me_fd, pending, sizeof(MDB_meta), offset); if (unlikely(rc != sizeof(MDB_meta))) { rc = (rc < 0) ? errno : EIO; if (rc == EINTR) goto retry; undo: mdbx_debug("write failed, disk error?"); /* On a failure, the pagecache still contains the new data. * Write some old data back, to prevent it from being used. */ if (pwrite(env->me_fd, (void *)target, sizeof(MDB_meta), offset) == sizeof(MDB_meta)) { /* LY: take a chance, if write succeeds at a magic ;) */ goto retry; } goto fail; } mdbx_invalidate_cache(env->me_map + offset, sizeof(MDB_meta)); #ifdef __SANITIZE_THREAD__ pthread_mutex_lock(&tsan_mutex); #endif } /* Memory ordering issues are irrelevant; since the entire writer * is wrapped by wmutex, all of these changes will become visible * after the wmutex is unlocked. Since the DB is multi-version, * readers will get consistent data regardless of how fresh or * how stale their view of these values is. */ env->me_txns->mti_txnid = pending->mm_txnid; #ifdef __SANITIZE_THREAD__ pthread_mutex_unlock(&tsan_mutex); #endif /* LY: step#3 - sync meta-pages. */ if ((flags & (MDB_NOSYNC | MDB_NOMETASYNC)) == 0) { if (env->me_flags & MDB_WRITEMAP) { char *ptr = env->me_map + (offset & ~(env->me_os_psize - 1)); int mode = (flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC; if (unlikely(msync(ptr, env->me_os_psize, mode) < 0)) { rc = errno; goto fail; } } else { while (unlikely(fdatasync(env->me_fd) < 0)) { rc = errno; if (rc != EINTR) goto undo; } } } /* LY: currently this can't happen, but... */ if (unlikely(pending->mm_mapsize < prev_mapsize)) { mdbx_assert(env, pending->mm_mapsize == env->me_mapsize); if (unlikely(mremap(env->me_map, prev_mapsize, pending->mm_mapsize, MREMAP_FIXED, pending->mm_address) == MAP_FAILED)) { rc = errno; goto fail; } if (unlikely(ftruncate(env->me_fd, pending->mm_mapsize) < 0)) { rc = errno; goto fail; } } return MDB_SUCCESS; fail: env->me_flags |= MDB_FATAL_ERROR; return rc; } int __cold mdbx_env_create(MDB_env **env) { MDB_env *e; e = calloc(1, sizeof(MDB_env)); if (!e) return ENOMEM; e->me_maxreaders = DEFAULT_READERS; e->me_maxdbs = e->me_numdbs = CORE_DBS; e->me_fd = INVALID_HANDLE_VALUE; e->me_lfd = INVALID_HANDLE_VALUE; e->me_pid = getpid(); GET_PAGESIZE(e->me_os_psize); VALGRIND_CREATE_MEMPOOL(e, 0, 0); e->me_signature = MDBX_ME_SIGNATURE; *env = e; return MDB_SUCCESS; } static int __cold mdbx_env_map(MDB_env *env, void *addr, size_t usedsize) { unsigned flags = env->me_flags; int prot = PROT_READ; if (flags & MDB_WRITEMAP) { prot |= PROT_WRITE; if (ftruncate(env->me_fd, env->me_mapsize) < 0) return errno; } env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED, env->me_fd, 0); if (env->me_map == MAP_FAILED) { env->me_map = NULL; return errno; } /* Can happen because the address argument to mmap() is just a * hint. mmap() can pick another, e.g. if the range is in use. * The MAP_FIXED flag would prevent that, but then mmap could * instead unmap existing pages to make room for the new map. */ if (addr && env->me_map != addr) { errno = 0; /* LY: clean errno as a hit for this case */ return EBUSY; /* TODO: Make a new MDB_* error code? */ } if (madvise(env->me_map, env->me_mapsize, MADV_DONTFORK)) return errno; #ifdef MADV_NOHUGEPAGE (void)madvise(env->me_map, env->me_mapsize, MADV_NOHUGEPAGE); #endif #ifdef MADV_DONTDUMP if (!(flags & MDBX_PAGEPERTURB)) { (void)madvise(env->me_map, env->me_mapsize, MADV_DONTDUMP); } #endif #ifdef MADV_REMOVE if (flags & MDB_WRITEMAP) { (void)madvise(env->me_map + usedsize, env->me_mapsize - usedsize, MADV_REMOVE); } #endif /* Turn on/off readahead. It's harmful when the DB is larger than RAM. */ if (madvise(env->me_map, env->me_mapsize, (flags & MDB_NORDAHEAD) ? MADV_RANDOM : MADV_WILLNEED)) return errno; /* Lock meta pages to avoid unexpected write, * before the data pages would be synchronized. */ if ((flags & MDB_WRITEMAP) && mlock(env->me_map, env->me_psize * 2)) return errno; #ifdef USE_VALGRIND env->me_valgrind_handle = VALGRIND_CREATE_BLOCK(env->me_map, env->me_mapsize, "lmdb"); #endif return MDB_SUCCESS; } int __cold mdbx_env_set_mapsize(MDB_env *env, size_t size) { if (unlikely(!env)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(size < env->me_psize * 8)) return EINVAL; /* If env is already open, caller is responsible for making * sure there are no active txns. */ if (env->me_map) { int rc; MDB_meta *meta; void *old; if (env->me_txn) return EINVAL; meta = mdbx_meta_head_w(env); if (!size) size = meta->mm_mapsize; /* Silently round up to minimum if the size is too small */ const size_t usedsize = (meta->mm_last_pg + 1) * env->me_psize; if (size < usedsize) size = usedsize; munmap(env->me_map, env->me_mapsize); #ifdef USE_VALGRIND VALGRIND_DISCARD(env->me_valgrind_handle); env->me_valgrind_handle = -1; #endif env->me_mapsize = size; old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL; rc = mdbx_env_map(env, old, usedsize); if (rc) return rc; } env->me_mapsize = size; if (env->me_psize) env->me_maxpg = env->me_mapsize / env->me_psize; return MDB_SUCCESS; } int __cold mdbx_env_set_maxdbs(MDB_env *env, MDB_dbi dbs) { if (unlikely(!env)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(env->me_map)) return EINVAL; env->me_maxdbs = dbs + CORE_DBS; return MDB_SUCCESS; } int __cold mdbx_env_set_maxreaders(MDB_env *env, unsigned readers) { if (unlikely(!env || readers < 1)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(env->me_map)) return EINVAL; env->me_maxreaders = readers; return MDB_SUCCESS; } int __cold mdbx_env_get_maxreaders(MDB_env *env, unsigned *readers) { if (!env || !readers) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; *readers = env->me_maxreaders; return MDB_SUCCESS; } static int __cold mdbx_fsize(HANDLE fd, size_t *size) { struct stat st; if (fstat(fd, &st)) return errno; *size = st.st_size; return MDB_SUCCESS; } /** Further setup required for opening an LMDB environment */ static int __cold mdbx_env_open2(MDB_env *env, MDB_meta *meta) { unsigned flags = env->me_flags; int i, newenv = 0, rc; if ((i = mdbx_env_read_header(env, meta)) != 0) { if (i != ENOENT) return i; mdbx_debug("new mdbenv"); newenv = 1; env->me_psize = env->me_os_psize; if (env->me_psize > MAX_PAGESIZE) env->me_psize = MAX_PAGESIZE; memset(meta, 0, sizeof(*meta)); mdbx_env_init_meta0(env, meta); meta->mm_mapsize = DEFAULT_MAPSIZE; } else { env->me_psize = meta->mm_psize; } /* Was a mapsize configured? */ if (!env->me_mapsize) { env->me_mapsize = meta->mm_mapsize; } { /* Make sure mapsize >= committed data size. Even when using * mm_mapsize, which could be broken in old files (ITS#7789). */ size_t minsize = (meta->mm_last_pg + 1) * meta->mm_psize; if (env->me_mapsize < minsize) env->me_mapsize = minsize; } meta->mm_mapsize = env->me_mapsize; if (newenv && !(flags & MDB_FIXEDMAP)) { /* mdbx_env_map() may grow the datafile. Write the metapages * first, so the file will be valid if initialization fails. * Except with FIXEDMAP, since we do not yet know mm_address. * We could fill in mm_address later, but then a different * program might end up doing that - one with a memory layout * and map address which does not suit the main program. */ rc = mdbx_env_init_meta(env, meta); if (rc) return rc; newenv = 0; } const size_t usedsize = (meta->mm_last_pg + 1) * env->me_psize; rc = mdbx_env_map(env, (flags & MDB_FIXEDMAP) ? meta->mm_address : NULL, usedsize); if (rc) return rc; if (newenv) { if (flags & MDB_FIXEDMAP) meta->mm_address = env->me_map; i = mdbx_env_init_meta(env, meta); if (i != MDB_SUCCESS) { return i; } } env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1; env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2) - sizeof(indx_t); env->me_maxkey_limit = env->me_nodemax - (NODESIZE + sizeof(MDB_db)); env->me_maxpg = env->me_mapsize / env->me_psize; if (MDB_MAXKEYSIZE > env->me_maxkey_limit) return MDB_BAD_VALSIZE; return MDB_SUCCESS; } /****************************************************************************/ #ifndef MDBX_USE_THREAD_ATEXIT #if __GLIBC_PREREQ(2, 18) #define MDBX_USE_THREAD_ATEXIT 1 #else #define MDBX_USE_THREAD_ATEXIT 0 #endif #endif static pthread_mutex_t mdbx_rthc_mutex = PTHREAD_MUTEX_INITIALIZER; static MDBX_rthc *mdbx_rthc_list; static pthread_key_t mdbx_pthread_crutch_key; static __inline void mdbx_rthc_lock(void) { mdbx_ensure(NULL, pthread_mutex_lock(&mdbx_rthc_mutex) == 0); } static __inline void mdbx_rthc_unlock(void) { mdbx_ensure(NULL, pthread_mutex_unlock(&mdbx_rthc_mutex) == 0); } /** Release a reader thread's slot in the reader lock table. * This function is called automatically when a thread exits. * @param[in] ptr This points to the MDB_rthc of a slot in the reader lock *table. */ static __cold void mdbx_rthc_dtor(void) { /* LY: Основная задача этого деструктора была и есть в освобождении * слота таблицы читателей при завершении треда, но тут есть пара * не очевидных сложностей: * - Таблица читателей располагается в разделяемой памяти, поэтому * во избежание segfault деструктор не должен что-либо делать после * или одновременно с mdbx_env_close(). * - Действительно, mdbx_env_close() вызовет pthread_key_delete() и * после этого glibc не будет вызывать деструктор. * - ОДНАКО, это никак не решает проблему гонок между mdbx_env_close() * и завершающимися тредами. Грубо говоря, при старте mdbx_env_close() * деструктор уже может выполняться в некоторых тредах, и завершиться * эти выполнения могут во время или после окончания mdbx_env_close(). * - БОЛЕЕ ТОГО, схожая проблема возникает при выгрузке dso/dll, * так как в текущей glibc (2.24) подсистема ld.so ничего не знает о * TSD-деструкторах и поэтому может выгрузить lib.so до того как * отработали все деструкторы. * - Исходное проявление проблемы было зафиксировано * в https://github.com/ReOpen/ReOpenLDAP/issues/48 * * Предыдущее решение посредством выделяемого динамически MDB_rthc * было не удачным, так как порождало либо утечку памяти, * либо вероятностное обращение к уже освобожденной памяти * из этого деструктора. * * Текущее решение достаточно "развесисто", но решает все описанные выше * проблемы без пенальти по производительности. */ mdbx_rthc_lock(); pid_t pid = getpid(); pthread_t thread = pthread_self(); for (MDBX_rthc **ref = &mdbx_rthc_list; *ref;) { MDBX_rthc *rthc = *ref; if (rthc->rc_thread == thread) { if (rthc->rc_reader && rthc->rc_reader->mr_pid == pid) { rthc->rc_reader->mr_pid = 0; mdbx_coherent_barrier(); } *ref = rthc->rc_next; free(rthc); } else { ref = &(*ref)->rc_next; } } mdbx_rthc_unlock(); } #if MDBX_USE_THREAD_ATEXIT extern void *__dso_handle __attribute__((__weak__)); extern int __cxa_thread_atexit_impl(void (*dtor)(void *), void *obj, void *dso_symbol); static __cold void mdbx_rthc__thread_atexit(void *ptr) { mdbx_ensure(NULL, ptr == pthread_getspecific(mdbx_pthread_crutch_key)); mdbx_ensure(NULL, pthread_setspecific(mdbx_pthread_crutch_key, NULL) == 0); mdbx_rthc_dtor(); } static __attribute__((constructor)) __cold void mdbx_pthread_crutch_ctor(void) { mdbx_ensure(NULL, pthread_key_create(&mdbx_pthread_crutch_key, NULL) == 0); } #else /* MDBX_USE_THREAD_ATEXIT */ static __cold void mdbx_rthc__thread_key_dtor(void *ptr) { (void)ptr; if (mdbx_pthread_crutch_key != (pthread_key_t)-1) mdbx_rthc_dtor(); } static __attribute__((constructor)) __cold void mdbx_pthread_crutch_ctor(void) { mdbx_ensure(NULL, pthread_key_create(&mdbx_pthread_crutch_key, mdbx_rthc__thread_key_dtor) == 0); } static __attribute__((destructor)) __cold void mdbx_pthread_crutch_dtor(void) { pthread_key_delete(mdbx_pthread_crutch_key); mdbx_pthread_crutch_key = -1; /* LY: Из-за race condition в pthread_key_delete() * деструкторы уже могли начать выполняться. * Уступая квант времени сразу после удаления ключа * мы даем им шанс завершиться. */ pthread_yield(); mdbx_rthc_lock(); pid_t pid = getpid(); while (mdbx_rthc_list != NULL) { MDBX_rthc *rthc = mdbx_rthc_list; mdbx_rthc_list = mdbx_rthc_list->rc_next; if (rthc->rc_reader && rthc->rc_reader->mr_pid == pid) { rthc->rc_reader->mr_pid = 0; mdbx_coherent_barrier(); } free(rthc); /* LY: Каждый неудаленный элемент списка - это один * не отработавший деструктор и потенциальный * шанс получить segfault после выгрузки lib.so * Поэтому на каждой итерации уступаем квант времени, * в надежде что деструкторы успеют отработать. */ mdbx_rthc_unlock(); pthread_yield(); mdbx_rthc_lock(); } mdbx_rthc_unlock(); pthread_yield(); } #endif /* MDBX_USE_THREAD_ATEXIT */ static __cold MDBX_rthc *mdbx_rthc_add(pthread_key_t key) { MDBX_rthc *rthc = malloc(sizeof(MDBX_rthc)); if (unlikely(rthc == NULL)) goto bailout; rthc->rc_next = NULL; rthc->rc_reader = NULL; rthc->rc_thread = pthread_self(); if (unlikely(pthread_setspecific(key, rthc) != 0)) goto bailout_free; mdbx_rthc_lock(); if (pthread_getspecific(mdbx_pthread_crutch_key) == NULL) { #if MDBX_USE_THREAD_ATEXIT void *dso_anchor = (&__dso_handle && __dso_handle) ? __dso_handle : (void *)mdbx_version; if (unlikely(__cxa_thread_atexit_impl(mdbx_rthc__thread_atexit, rthc, dso_anchor) != 0)) { mdbx_rthc_unlock(); goto bailout_free; } #endif /* MDBX_USE_THREAD_ATEXIT */ mdbx_ensure(NULL, pthread_setspecific(mdbx_pthread_crutch_key, rthc) == 0); } rthc->rc_next = mdbx_rthc_list; mdbx_rthc_list = rthc; mdbx_rthc_unlock(); return rthc; bailout_free: free(rthc); bailout: return NULL; } static __inline MDBX_rthc *mdbx_rthc_get(pthread_key_t key) { MDBX_rthc *rthc = pthread_getspecific(key); if (likely(rthc != NULL)) return rthc; return mdbx_rthc_add(key); } static __cold void mdbx_rthc_cleanup(MDB_env *env) { mdbx_rthc_lock(); MDB_reader *begin = env->me_txns->mti_readers; MDB_reader *end = begin + env->me_close_readers; for (MDBX_rthc **ref = &mdbx_rthc_list; *ref;) { MDBX_rthc *rthc = *ref; if (rthc->rc_reader >= begin && rthc->rc_reader < end) { if (rthc->rc_reader->mr_pid == env->me_pid) { rthc->rc_reader->mr_pid = 0; mdbx_coherent_barrier(); } *ref = rthc->rc_next; free(rthc); } else { ref = &(*ref)->rc_next; } } mdbx_rthc_unlock(); } /****************************************************************************/ /** Downgrade the exclusive lock on the region back to shared */ static __cold int mdbx_env_share_locks(MDB_env *env, int *excl) { struct flock lock_info; int rc = 0; /* The shared lock replaces the existing lock */ memset((void *)&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_RDLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = 0; lock_info.l_len = 1; while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) && (rc = errno) == EINTR) ; *excl = rc ? -1 : 0; /* error may mean we lost the lock */ return rc; } /** Try to get exclusive lock, otherwise shared. * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive. */ static int __cold mdbx_env_excl_lock(MDB_env *env, int *excl) { int rc = 0; struct flock lock_info; memset((void *)&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_WRLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = 0; lock_info.l_len = 1; while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) && (rc = errno) == EINTR) ; if (!rc) { *excl = 1; } else { lock_info.l_type = F_RDLCK; while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) && (rc = errno) == EINTR) ; if (rc == 0) *excl = 0; } return rc; } #ifdef MDB_USE_HASH /* * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code * * @(#) $Revision: 5.1 $ * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $ * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $ * * http://www.isthe.com/chongo/tech/comp/fnv/index.html * *** * * Please do not copyright this code. This code is in the public domain. * * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. * * By: * chongo /\oo/\ * http://www.isthe.com/chongo/ * * Share and Enjoy! :-) */ typedef unsigned long long mdbx_hash_t; #define MDB_HASH_INIT ((mdbx_hash_t)0xcbf29ce484222325ULL) /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer * @param[in] val value to hash * @param[in] hval initial value for hash * @return 64 bit hash * * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the * hval arg on the first call. */ static mdbx_hash_t mdbx_hash_val(MDB_val *val, mdbx_hash_t hval) { unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */ unsigned char *end = s + val->mv_size; /* * FNV-1a hash each octet of the string */ while (s < end) { /* xor the bottom with the current octet */ hval ^= (mdbx_hash_t)*s++; /* multiply by the 64 bit FNV magic prime mod 2^64 */ hval += (hval << 1) + (hval << 4) + (hval << 5) + (hval << 7) + (hval << 8) + (hval << 40); } /* return our new hash value */ return hval; } /** Hash the string and output the encoded hash. * This uses modified RFC1924 Ascii85 encoding to accommodate systems with * very short name limits. We don't care about the encoding being reversible, * we just want to preserve as many bits of the input as possible in a * small printable string. * @param[in] str string to hash * @param[out] encbuf an array of 11 chars to hold the hash */ static const char mdbx_a85[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghij" "klmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~"; static void __cold mdbx_pack85(unsigned long l, char *out) { int i; for (i = 0; i < 5; i++) { *out++ = mdbx_a85[l % 85]; l /= 85; } } static void __cold mdbx_hash_enc(MDB_val *val, char *encbuf) { mdbx_hash_t h = mdbx_hash_val(val, MDB_HASH_INIT); mdbx_pack85(h, encbuf); mdbx_pack85(h >> 32, encbuf + 5); encbuf[10] = '\0'; } #endif /** Open and/or initialize the lock region for the environment. * @param[in] env The LMDB environment. * @param[in] lpath The pathname of the file used for the lock region. * @param[in] mode The Unix permissions for the file, if we create it. * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive * @return 0 on success, non-zero on failure. */ static int __cold mdbx_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl) { int fdflags; int rc; off_t size, rsize; void *m; env->me_lfd = open(lpath, O_RDWR | O_CREAT | O_CLOEXEC, mode); if (env->me_lfd == INVALID_HANDLE_VALUE) { rc = errno; if (rc == EROFS && (env->me_flags & MDB_RDONLY)) { return MDB_SUCCESS; } return rc; } /* Lose record locks when exec*() */ if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0) fcntl(env->me_lfd, F_SETFD, fdflags); if (!(env->me_flags & MDB_NOTLS)) { rc = pthread_key_create(&env->me_txkey, NULL); if (rc) return rc; env->me_flags |= MDB_ENV_TXKEY; } /* Try to get exclusive lock. If we succeed, then * nobody is using the lock region and we should initialize it. */ if ((rc = mdbx_env_excl_lock(env, excl))) return rc; size = lseek(env->me_lfd, 0, SEEK_END); if (size == -1) return errno; rsize = (env->me_maxreaders - 1) * sizeof(MDB_reader) + sizeof(MDB_txninfo); if (size 0) { if (ftruncate(env->me_lfd, rsize) != 0) return errno; } else { rsize = size; size = rsize - sizeof(MDB_txninfo); env->me_maxreaders = size / sizeof(MDB_reader) + 1; } m = mmap(NULL, rsize, PROT_READ | PROT_WRITE, MAP_SHARED, env->me_lfd, 0); if (m == MAP_FAILED) return errno; env->me_txns = m; #ifdef MADV_NOHUGEPAGE (void)madvise(env->me_txns, rsize, MADV_NOHUGEPAGE); #endif #ifdef MADV_DODUMP (void)madvise(env->me_txns, rsize, MADV_DODUMP); #endif if (madvise(env->me_txns, rsize, MADV_DONTFORK) < 0) return errno; if (madvise(env->me_txns, rsize, MADV_WILLNEED) < 0) return errno; if (madvise(env->me_txns, rsize, MADV_RANDOM) < 0) return errno; if (*excl > 0) { /* Solaris needs this before initing a robust mutex. Otherwise * it may skip the init and return EBUSY "seems someone already * inited" or EINVAL "it was inited differently". */ memset(&env->me_txns->mti_rmutex, 0, sizeof(env->me_txns->mti_rmutex)); memset(&env->me_txns->mti_wmutex, 0, sizeof(env->me_txns->mti_wmutex)); pthread_mutexattr_t mattr; rc = pthread_mutexattr_init(&mattr); if (rc) return rc; rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED); #if MDB_USE_ROBUST if (!rc) rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST); #endif /* MDB_USE_ROBUST */ if (!rc) rc = pthread_mutex_init(&env->me_txns->mti_rmutex, &mattr); if (!rc) rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr); pthread_mutexattr_destroy(&mattr); if (rc) return rc; env->me_txns->mti_magic = MDB_MAGIC; env->me_txns->mti_format = MDB_LOCK_FORMAT; env->me_txns->mti_txnid = ~0L; env->me_txns->mti_numreaders = 0; } else { if (env->me_txns->mti_magic != MDB_MAGIC) { mdbx_debug("lock region has invalid magic"); return MDB_INVALID; } if (env->me_txns->mti_format != MDB_LOCK_FORMAT) { mdbx_debug("lock region has format+version 0x%x, expected 0x%x", env->me_txns->mti_format, MDB_LOCK_FORMAT); return MDB_VERSION_MISMATCH; } } return MDB_SUCCESS; } /** The name of the lock file in the DB environment */ #define LOCKNAME "/lock.mdb" /** The name of the data file in the DB environment */ #define DATANAME "/data.mdb" /** The suffix of the lock file when no subdir is used */ #define LOCKSUFF "-lock" /** Only a subset of the @ref mdbx_env flags can be changed * at runtime. Changing other flags requires closing the * environment and re-opening it with the new flags. */ #define CHANGEABLE \ (MDB_NOSYNC | MDB_NOMETASYNC | MDB_MAPASYNC | MDB_NOMEMINIT | \ MDBX_COALESCE | MDBX_PAGEPERTURB) #define CHANGELESS \ (MDB_FIXEDMAP | MDB_NOSUBDIR | MDB_RDONLY | MDB_WRITEMAP | MDB_NOTLS | \ MDB_NORDAHEAD | MDBX_LIFORECLAIM) #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE | CHANGELESS) #error "Persistent DB flags & env flags overlap, but both go in mm_flags" #endif int __cold mdbx_env_open_ex(MDB_env *env, const char *path, unsigned flags, mode_t mode, int *exclusive) { int oflags, rc, len, excl = -1; char *lpath, *dpath; if (unlikely(!env || !path)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; if (env->me_fd != INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE | CHANGELESS))) return EINVAL; len = strlen(path); if (flags & MDB_NOSUBDIR) { rc = len + sizeof(LOCKSUFF) + len + 1; } else { rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME); } lpath = malloc(rc); if (!lpath) return ENOMEM; if (flags & MDB_NOSUBDIR) { dpath = lpath + len + sizeof(LOCKSUFF); sprintf(lpath, "%s" LOCKSUFF, path); strcpy(dpath, path); } else { dpath = lpath + len + sizeof(LOCKNAME); sprintf(lpath, "%s" LOCKNAME, path); sprintf(dpath, "%s" DATANAME, path); } rc = MDB_SUCCESS; flags |= env->me_flags; if (flags & MDB_RDONLY) { /* LY: silently ignore irrelevant flags when we're only getting read * access */ flags &= ~(MDB_WRITEMAP | MDB_MAPASYNC | MDB_NOSYNC | MDB_NOMETASYNC | MDBX_COALESCE | MDBX_LIFORECLAIM | MDB_NOMEMINIT); } else { if (!((env->me_free_pgs = mdbx_midl_alloc(MDB_IDL_UM_MAX)) && (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2))))) rc = ENOMEM; } env->me_flags = flags |= MDB_ENV_ACTIVE; if (rc) goto leave; env->me_path = strdup(path); env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx)); env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t)); env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned)); if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) { rc = ENOMEM; goto leave; } env->me_dbxs[FREE_DBI].md_cmp = mdbx_cmp_int_ai; /* aligned MDB_INTEGERKEY */ /* For RDONLY, get lockfile after we know datafile exists */ if (!(flags & MDB_RDONLY)) { rc = mdbx_env_setup_locks(env, lpath, mode, &excl); if (rc) goto leave; } if (F_ISSET(flags, MDB_RDONLY)) oflags = O_RDONLY; else oflags = O_RDWR | O_CREAT; env->me_fd = open(dpath, oflags | O_CLOEXEC, mode); if (env->me_fd == INVALID_HANDLE_VALUE) { rc = errno; goto leave; } int fdflags; if ((fdflags = fcntl(env->me_fd, F_GETFD) | FD_CLOEXEC) >= 0) fcntl(env->me_fd, F_SETFD, fdflags); if (flags & MDB_RDONLY) { rc = mdbx_env_setup_locks(env, lpath, mode, &excl); if (rc) goto leave; } MDB_meta meta; if ((rc = mdbx_env_open2(env, &meta)) == MDB_SUCCESS) { mdbx_debug("opened dbenv %p", (void *)env); if (excl > 0) { env->me_txns->mti_txnid = meta.mm_txnid; if (exclusive == NULL || *exclusive < 2) { /* LY: downgrade lock only if exclusive access not requested. * in case exclusive==1, just leave value as is. */ rc = mdbx_env_share_locks(env, &excl); if (rc) goto leave; } } else if (exclusive) { /* LY: just indicate that is not an exclusive access. */ *exclusive = 0; } if (!(flags & MDB_RDONLY)) { MDB_txn *txn; int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs * (sizeof(MDB_db) + sizeof(MDB_cursor *) + sizeof(unsigned) + 1); if ((env->me_pbuf = calloc(1, env->me_psize)) && (txn = calloc(1, size))) { txn->mt_dbs = (MDB_db *)((char *)txn + tsize); txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs); txn->mt_dbiseqs = (unsigned *)(txn->mt_cursors + env->me_maxdbs); txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs); txn->mt_env = env; txn->mt_dbxs = env->me_dbxs; txn->mt_flags = MDB_TXN_FINISHED; env->me_txn0 = txn; } else { rc = ENOMEM; } } } #if MDB_DEBUG if (rc == MDB_SUCCESS) { MDB_meta *meta = mdbx_meta_head_r(env); MDB_db *db = &meta->mm_dbs[MAIN_DBI]; int toggle = ((char *)meta == PAGEDATA(env->me_map)) ? 0 : 1; mdbx_debug("opened database version %u, pagesize %u", meta->mm_version, env->me_psize); mdbx_debug("using meta page %d, txn %zu", toggle, meta->mm_txnid); mdbx_debug("depth: %u", db->md_depth); mdbx_debug("entries: %zu", db->md_entries); mdbx_debug("branch pages: %zu", db->md_branch_pages); mdbx_debug("leaf pages: %zu", db->md_leaf_pages); mdbx_debug("overflow pages: %zu", db->md_overflow_pages); mdbx_debug("root: %zu", db->md_root); } #endif leave: if (rc) mdbx_env_close0(env); free(lpath); return rc; } int __cold mdbx_env_open(MDB_env *env, const char *path, unsigned flags, mode_t mode) { return mdbx_env_open_ex(env, path, flags, mode, NULL); } /** Destroy resources from mdbx_env_open(), clear our readers & DBIs */ static void __cold mdbx_env_close0(MDB_env *env) { int i; if (!(env->me_flags & MDB_ENV_ACTIVE)) return; env->me_flags &= ~MDB_ENV_ACTIVE; /* Doing this here since me_dbxs may not exist during mdbx_env_close */ if (env->me_dbxs) { for (i = env->me_maxdbs; --i >= CORE_DBS;) free(env->me_dbxs[i].md_name.mv_data); free(env->me_dbxs); } free(env->me_pbuf); free(env->me_dbiseqs); free(env->me_dbflags); free(env->me_path); free(env->me_dirty_list); if (env->me_txn0) mdbx_midl_free(env->me_txn0->mt_lifo_reclaimed); free(env->me_txn0); mdbx_midl_free(env->me_free_pgs); if (env->me_flags & MDB_ENV_TXKEY) { mdbx_ensure(env, pthread_key_delete(env->me_txkey) == 0); env->me_flags &= ~MDB_ENV_TXKEY; } if (env->me_map) { munmap(env->me_map, env->me_mapsize); #ifdef USE_VALGRIND VALGRIND_DISCARD(env->me_valgrind_handle); env->me_valgrind_handle = -1; #endif } if (env->me_fd != INVALID_HANDLE_VALUE) (void)close(env->me_fd); /* Clearing readers is done in this function because * me_txkey with its destructor must be disabled first. * * We skip the the reader mutex, so we touch only * data owned by this process (me_close_readers and * our readers), and clear each reader atomically. */ if (env->me_pid == getpid()) mdbx_rthc_cleanup(env); munmap((void *)env->me_txns, (env->me_maxreaders - 1) * sizeof(MDB_reader) + sizeof(MDB_txninfo)); env->me_txns = NULL; env->me_pid = 0; if (env->me_lfd != INVALID_HANDLE_VALUE) { (void)close(env->me_lfd); } } int __cold mdbx_env_close_ex(MDB_env *env, int dont_sync) { MDB_page *dp; int rc = MDB_SUCCESS; if (unlikely(!env)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; if (!dont_sync && env->me_txns) rc = mdbx_env_sync(env, 1); VALGRIND_DESTROY_MEMPOOL(env); while ((dp = env->me_dpages) != NULL) { ASAN_UNPOISON_MEMORY_REGION(&dp->mp_next, sizeof(dp->mp_next)); VALGRIND_MAKE_MEM_DEFINED(&dp->mp_next, sizeof(dp->mp_next)); env->me_dpages = dp->mp_next; free(dp); } mdbx_env_close0(env); env->me_signature = 0; free(env); return rc; } void __cold mdbx_env_close(MDB_env *env) { mdbx_env_close_ex(env, 0); } /* LY: fast enough on most arches * * / * | -1, a < b * cmp2int(a,b) = < 0, a == b * | 1, a > b * \ */ #if 1 #define mdbx_cmp2int(a, b) (((b) > (a)) ? -1 : (a) > (b)) #else #define mdbx_cmp2int(a, b) (((a) > (b)) - ((b) > (a))) #endif /** Compare two items pointing at aligned unsigned int's. */ static int __hot mdbx_cmp_int_ai(const MDB_val *a, const MDB_val *b) { mdbx_assert(NULL, a->mv_size == b->mv_size); mdbx_assert(NULL, 0 == (uintptr_t)a->mv_data % sizeof(int) && 0 == (uintptr_t)b->mv_data % sizeof(int)); if (sizeof(int) != sizeof(size_t) && likely(a->mv_size == sizeof(size_t))) return mdbx_cmp2int(*(size_t *)a->mv_data, *(size_t *)b->mv_data); mdbx_assert(NULL, a->mv_size == sizeof(int)); return mdbx_cmp2int(*(unsigned *)a->mv_data, *(unsigned *)b->mv_data); } /** Compare two items pointing at 2-byte aligned unsigned int's. */ static int __hot mdbx_cmp_int_a2(const MDB_val *a, const MDB_val *b) { mdbx_assert(NULL, a->mv_size == b->mv_size); mdbx_assert(NULL, 0 == (uintptr_t)a->mv_data % sizeof(uint16_t) && 0 == (uintptr_t)b->mv_data % sizeof(uint16_t)); #ifdef MISALIGNED_OK if (sizeof(int) != sizeof(size_t) && likely(a->mv_size == sizeof(size_t))) return mdbx_cmp2int(*(size_t *)a->mv_data, *(size_t *)b->mv_data); mdbx_assert(NULL, a->mv_size == sizeof(int)); return mdbx_cmp2int(*(unsigned *)a->mv_data, *(unsigned *)b->mv_data); #else mdbx_assert(NULL, 0 == a->mv_size % sizeof(uint16_t)); { int diff; const uint16_t *pa, *pb, *end; #if BYTE_ORDER == LITTLE_ENDIAN end = (const uint16_t *)a->mv_data; pa = (const uint16_t *)((char *)a->mv_data + a->mv_size); pb = (const uint16_t *)((char *)b->mv_data + a->mv_size); do { diff = *--pa - *--pb; #else /* BYTE_ORDER */ end = (const uint16_t *)((char *)a->mv_data + a->mv_size); pa = (const uint16_t *)a->mv_data; pb = (const uint16_t *)b->mv_data; do { diff = *pa++ - *pb++; #endif /* BYTE_ORDER */ if (likely(diff != 0)) break; } while (pa != end); return diff; } #endif /* MISALIGNED_OK */ } /** Compare two items pointing at unsigneds of unknown alignment. * * This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp. */ static int __hot mdbx_cmp_int_ua(const MDB_val *a, const MDB_val *b) { mdbx_assert(NULL, a->mv_size == b->mv_size); #if MISALIGNED_OK if (sizeof(int) != sizeof(size_t) && likely(a->mv_size == sizeof(size_t))) return mdbx_cmp2int(*(size_t *)a->mv_data, *(size_t *)b->mv_data); mdbx_assert(NULL, a->mv_size == sizeof(int)); return mdbx_cmp2int(*(unsigned *)a->mv_data, *(unsigned *)b->mv_data); #else mdbx_assert(NULL, a->mv_size == sizeof(int) || a->mv_size == sizeof(size_t)); #if BYTE_ORDER == LITTLE_ENDIAN { int diff; const uint8_t *pa, *pb; pa = (const uint8_t *)a->mv_data + a->mv_size; pb = (const uint8_t *)b->mv_data + a->mv_size; do { diff = *--pa - *--pb; if (likely(diff != 0)) break; } while (pa != a->mv_data); return diff; } #else /* BYTE_ORDER */ return memcmp(a->mv_data, b->mv_data, a->mv_size); #endif /* BYTE_ORDER */ #endif /* MISALIGNED_OK */ } /** Compare two items lexically */ static int __hot mdbx_cmp_memn(const MDB_val *a, const MDB_val *b) { /* LY: assumes that length of keys are NOT equal for most cases, * if no then branch-prediction should mitigate the problem */ #if 0 /* LY: without branch instructions on x86, * but isn't best for equal length of keys */ int diff_len = mdbx_cmp2int(a->mv_size, b->mv_size); #else /* LY: best when length of keys are equal, * but got a branch-penalty otherwise */ if (unlikely(a->mv_size == b->mv_size)) return memcmp(a->mv_data, b->mv_data, a->mv_size); int diff_len = (a->mv_size < b->mv_size) ? -1 : 1; #endif size_t shortest = (a->mv_size < b->mv_size) ? a->mv_size : b->mv_size; int diff_data = memcmp(a->mv_data, b->mv_data, shortest); return likely(diff_data) ? diff_data : diff_len; } /** Compare two items in reverse byte order */ static int __hot mdbx_cmp_memnr(const MDB_val *a, const MDB_val *b) { const uint8_t *pa, *pb, *end; pa = (const uint8_t *)a->mv_data + a->mv_size; pb = (const uint8_t *)b->mv_data + b->mv_size; size_t minlen = (a->mv_size < b->mv_size) ? a->mv_size : b->mv_size; end = pa - minlen; while (pa != end) { int diff = *--pa - *--pb; if (likely(diff)) return diff; } return mdbx_cmp2int(a->mv_size, b->mv_size); } /** Search for key within a page, using binary search. * Returns the smallest entry larger or equal to the key. * If exactp is non-null, stores whether the found entry was an exact match * in *exactp (1 or 0). * Updates the cursor index with the index of the found entry. * If no entry larger or equal to the key is found, returns NULL. */ static MDB_node *__hot mdbx_node_search(MDB_cursor *mc, MDB_val *key, int *exactp) { unsigned i = 0, nkeys; int low, high; int rc = 0; MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_node *node = NULL; MDB_val nodekey; MDB_cmp_func *cmp; DKBUF; nkeys = NUMKEYS(mp); mdbx_debug("searching %u keys in %s %spage %zu", nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "", mdbx_dbg_pgno(mp)); low = IS_LEAF(mp) ? 0 : 1; high = nkeys - 1; cmp = mc->mc_dbx->md_cmp; /* Branch pages have no data, so if using integer keys, * alignment is guaranteed. Use faster mdbx_cmp_int_ai. */ if (cmp == mdbx_cmp_int_a2 && IS_BRANCH(mp)) cmp = mdbx_cmp_int_ai; if (IS_LEAF2(mp)) { nodekey.mv_size = mc->mc_db->md_xsize; node = NODEPTR(mp, 0); /* fake */ while (low <= high) { i = (low + high) >> 1; nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size); rc = cmp(key, &nodekey); mdbx_debug("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc); if (rc == 0) break; if (rc > 0) low = i + 1; else high = i - 1; } } else { while (low <= high) { i = (low + high) >> 1; node = NODEPTR(mp, i); nodekey.mv_size = NODEKSZ(node); nodekey.mv_data = NODEKEY(node); rc = cmp(key, &nodekey); if (IS_LEAF(mp)) mdbx_debug("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc); else mdbx_debug("found branch index %u [%s -> %zu], rc = %i", i, DKEY(&nodekey), NODEPGNO(node), rc); if (rc == 0) break; if (rc > 0) low = i + 1; else high = i - 1; } } if (rc > 0) /* Found entry is less than the key. */ i++; /* Skip to get the smallest entry larger than key. */ if (exactp) *exactp = (rc == 0 && nkeys > 0); /* store the key index */ mc->mc_ki[mc->mc_top] = i; if (i >= nkeys) /* There is no entry larger or equal to the key. */ return NULL; /* nodeptr is fake for LEAF2 */ return IS_LEAF2(mp) ? node : NODEPTR(mp, i); } #if 0 static void mdbx_cursor_adjust(MDB_cursor *mc, func) { MDB_cursor *m2; for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) { func(mc, m2); } } } #endif /** Pop a page off the top of the cursor's stack. */ static void mdbx_cursor_pop(MDB_cursor *mc) { if (mc->mc_snum) { mdbx_debug("popped page %zu off db %d cursor %p", mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *)mc); mc->mc_snum--; if (mc->mc_snum) { mc->mc_top--; } else { mc->mc_flags &= ~C_INITIALIZED; } } } /** Push a page onto the top of the cursor's stack. * Set #MDB_TXN_ERROR on failure. */ static int mdbx_cursor_push(MDB_cursor *mc, MDB_page *mp) { mdbx_debug("pushing page %zu on db %d cursor %p", mp->mp_pgno, DDBI(mc), (void *)mc); if (unlikely(mc->mc_snum >= CURSOR_STACK)) { mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return MDB_CURSOR_FULL; } mc->mc_top = mc->mc_snum++; mc->mc_pg[mc->mc_top] = mp; mc->mc_ki[mc->mc_top] = 0; return MDB_SUCCESS; } /** Find the address of the page corresponding to a given page number. * Set #MDB_TXN_ERROR on failure. * @param[in] mc the cursor accessing the page. * @param[in] pgno the page number for the page to retrieve. * @param[out] ret address of a pointer where the page's address will be * stored. * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, * 0=mapped page. * @return 0 on success, non-zero on failure. */ static int mdbx_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **ret, int *lvl) { MDB_txn *txn = mc->mc_txn; MDB_env *env = txn->mt_env; MDB_page *p = NULL; int level; if (!(txn->mt_flags & (MDB_TXN_RDONLY | MDB_TXN_WRITEMAP))) { MDB_txn *tx2 = txn; level = 1; do { MDB_ID2L dl = tx2->mt_u.dirty_list; unsigned x; /* Spilled pages were dirtied in this txn and flushed * because the dirty list got full. Bring this page * back in from the map (but don't unspill it here, * leave that unless page_touch happens again). */ if (tx2->mt_spill_pgs) { MDB_ID pn = pgno << 1; x = mdbx_midl_search(tx2->mt_spill_pgs, pn); if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) goto mapped; } if (dl[0].mid) { unsigned x = mdbx_mid2l_search(dl, pgno); if (x <= dl[0].mid && dl[x].mid == pgno) { p = dl[x].mptr; goto done; } } level++; } while ((tx2 = tx2->mt_parent) != NULL); } if (unlikely(pgno >= txn->mt_next_pgno)) { mdbx_debug("page %zu not found", pgno); txn->mt_flags |= MDB_TXN_ERROR; return MDB_PAGE_NOTFOUND; } level = 0; mapped: p = (MDB_page *)(env->me_map + env->me_psize * pgno); done: *ret = p; if (lvl) *lvl = level; return MDB_SUCCESS; } /** Finish #mdbx_page_search() / #mdbx_page_search_lowest(). * The cursor is at the root page, set up the rest of it. */ static int mdbx_page_search_root(MDB_cursor *mc, MDB_val *key, int flags) { MDB_page *mp = mc->mc_pg[mc->mc_top]; int rc; DKBUF; while (IS_BRANCH(mp)) { MDB_node *node; indx_t i; mdbx_debug("branch page %zu has %u keys", mp->mp_pgno, NUMKEYS(mp)); /* Don't assert on branch pages in the FreeDB. We can get here * while in the process of rebalancing a FreeDB branch page; we must * let that proceed. ITS#8336 */ mdbx_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1); mdbx_debug("found index 0 to page %zu", NODEPGNO(NODEPTR(mp, 0))); if (flags & (MDB_PS_FIRST | MDB_PS_LAST)) { i = 0; if (flags & MDB_PS_LAST) { i = NUMKEYS(mp) - 1; /* if already init'd, see if we're already in right place */ if (mc->mc_flags & C_INITIALIZED) { if (mc->mc_ki[mc->mc_top] == i) { mc->mc_top = mc->mc_snum++; mp = mc->mc_pg[mc->mc_top]; goto ready; } } } } else { int exact; node = mdbx_node_search(mc, key, &exact); if (node == NULL) i = NUMKEYS(mp) - 1; else { i = mc->mc_ki[mc->mc_top]; if (!exact) { mdbx_cassert(mc, i > 0); i--; } } mdbx_debug("following index %u for key [%s]", i, DKEY(key)); } mdbx_cassert(mc, i < NUMKEYS(mp)); node = NODEPTR(mp, i); if (unlikely((rc = mdbx_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)) return rc; mc->mc_ki[mc->mc_top] = i; if (unlikely(rc = mdbx_cursor_push(mc, mp))) return rc; ready: if (flags & MDB_PS_MODIFY) { if (unlikely((rc = mdbx_page_touch(mc)) != 0)) return rc; mp = mc->mc_pg[mc->mc_top]; } } if (unlikely(!IS_LEAF(mp))) { mdbx_debug("internal error, index points to a %02X page!?", mp->mp_flags); mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return MDB_CORRUPTED; } mdbx_debug("found leaf page %zu for key [%s]", mp->mp_pgno, key ? DKEY(key) : "null"); mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; return MDB_SUCCESS; } /** Search for the lowest key under the current branch page. * This just bypasses a NUMKEYS check in the current page * before calling mdbx_page_search_root(), because the callers * are all in situations where the current page is known to * be underfilled. */ static int mdbx_page_search_lowest(MDB_cursor *mc) { MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_node *node = NODEPTR(mp, 0); int rc; if (unlikely((rc = mdbx_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)) return rc; mc->mc_ki[mc->mc_top] = 0; if (unlikely(rc = mdbx_cursor_push(mc, mp))) return rc; return mdbx_page_search_root(mc, NULL, MDB_PS_FIRST); } /** Search for the page a given key should be in. * Push it and its parent pages on the cursor stack. * @param[in,out] mc the cursor for this operation. * @param[in] key the key to search for, or NULL for first/last page. * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB * are touched (updated with new page numbers). * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf. * This is used by #mdbx_cursor_first() and #mdbx_cursor_last(). * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups. * @return 0 on success, non-zero on failure. */ static int mdbx_page_search(MDB_cursor *mc, MDB_val *key, int flags) { int rc; pgno_t root; /* Make sure the txn is still viable, then find the root from * the txn's db table and set it as the root of the cursor's stack. */ if (unlikely(mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)) { mdbx_debug("transaction has failed, must abort"); return MDB_BAD_TXN; } else { /* Make sure we're using an up-to-date root */ if (unlikely(*mc->mc_dbflag & DB_STALE)) { MDB_cursor mc2; if (unlikely(TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))) return MDB_BAD_DBI; mdbx_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL); rc = mdbx_page_search(&mc2, &mc->mc_dbx->md_name, 0); if (rc) return rc; { MDB_val data; int exact = 0; uint16_t flags; MDB_node *leaf = mdbx_node_search(&mc2, &mc->mc_dbx->md_name, &exact); if (!exact) return MDB_NOTFOUND; if (unlikely((leaf->mn_flags & (F_DUPDATA | F_SUBDATA)) != F_SUBDATA)) return MDB_INCOMPATIBLE; /* not a named DB */ rc = mdbx_node_read(&mc2, leaf, &data); if (rc) return rc; memcpy(&flags, ((char *)data.mv_data + offsetof(MDB_db, md_flags)), sizeof(uint16_t)); /* The txn may not know this DBI, or another process may * have dropped and recreated the DB with other flags. */ if (unlikely((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)) return MDB_INCOMPATIBLE; memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db)); } *mc->mc_dbflag &= ~DB_STALE; } root = mc->mc_db->md_root; if (unlikely(root == P_INVALID)) { /* Tree is empty. */ mdbx_debug("tree is empty"); return MDB_NOTFOUND; } } mdbx_cassert(mc, root > 1); if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) if (unlikely((rc = mdbx_page_get(mc, root, &mc->mc_pg[0], NULL)) != 0)) return rc; mc->mc_snum = 1; mc->mc_top = 0; mdbx_debug("db %d root page %zu has flags 0x%X", DDBI(mc), root, mc->mc_pg[0]->mp_flags); if (flags & MDB_PS_MODIFY) { if (unlikely(rc = mdbx_page_touch(mc))) return rc; } if (flags & MDB_PS_ROOTONLY) return MDB_SUCCESS; return mdbx_page_search_root(mc, key, flags); } static int mdbx_ovpage_free(MDB_cursor *mc, MDB_page *mp) { MDB_txn *txn = mc->mc_txn; pgno_t pg = mp->mp_pgno; unsigned x = 0, ovpages = mp->mp_pages; MDB_env *env = txn->mt_env; MDB_IDL sl = txn->mt_spill_pgs; MDB_ID pn = pg << 1; int rc; mdbx_debug("free ov page %zu (%u)", pg, ovpages); /* If the page is dirty or on the spill list we just acquired it, * so we should give it back to our current free list, if any. * Otherwise put it onto the list of pages we freed in this txn. * * Won't create me_pghead: me_pglast must be inited along with it. * Unsupported in nested txns: They would need to hide the page * range in ancestor txns' dirty and spilled lists. */ if (env->me_pghead && !txn->mt_parent && ((mp->mp_flags & P_DIRTY) || (sl && (x = mdbx_midl_search(sl, pn)) <= sl[0] && sl[x] == pn))) { unsigned i, j; pgno_t *mop; MDB_ID2 *dl, ix, iy; rc = mdbx_midl_need(&env->me_pghead, ovpages); if (unlikely(rc)) return rc; if (!(mp->mp_flags & P_DIRTY)) { /* This page is no longer spilled */ if (x == sl[0]) sl[0]--; else sl[x] |= 1; goto release; } /* Remove from dirty list */ dl = txn->mt_u.dirty_list; x = dl[0].mid--; for (ix = dl[x]; ix.mptr != mp; ix = iy) { if (likely(x > 1)) { x--; iy = dl[x]; dl[x] = ix; } else { mdbx_cassert(mc, x > 1); j = ++(dl[0].mid); dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */ txn->mt_flags |= MDB_TXN_ERROR; return MDB_PROBLEM; } } txn->mt_dirty_room++; if (!(env->me_flags & MDB_WRITEMAP)) mdbx_dpage_free(env, mp); release: /* Insert in me_pghead */ mop = env->me_pghead; j = mop[0] + ovpages; for (i = mop[0]; i && mop[i] < pg; i--) mop[j--] = mop[i]; while (j > i) mop[j--] = pg++; mop[0] += ovpages; } else { rc = mdbx_midl_append_range(&txn->mt_free_pgs, pg, ovpages); if (unlikely(rc)) return rc; } mc->mc_db->md_overflow_pages -= ovpages; return 0; } /** Return the data associated with a given node. * @param[in] mc The cursor for this operation. * @param[in] leaf The node being read. * @param[out] data Updated to point to the node's data. * @return 0 on success, non-zero on failure. */ static MDBX_INLINE int mdbx_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data) { MDB_page *omp; /* overflow page */ pgno_t pgno; int rc; if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) { data->mv_size = NODEDSZ(leaf); data->mv_data = NODEDATA(leaf); return MDB_SUCCESS; } /* Read overflow data. */ data->mv_size = NODEDSZ(leaf); memcpy(&pgno, NODEDATA(leaf), sizeof(pgno)); if (unlikely((rc = mdbx_page_get(mc, pgno, &omp, NULL)) != 0)) { mdbx_debug("read overflow page %zu failed", pgno); return rc; } data->mv_data = PAGEDATA(omp); return MDB_SUCCESS; } int mdbx_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) { MDB_cursor mc; MDB_xcursor mx; int exact = 0; DKBUF; mdbx_debug("===> get db %u key [%s]", dbi, DKEY(key)); if (unlikely(!key || !data || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; if (unlikely(txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; mdbx_cursor_init(&mc, txn, dbi, &mx); return mdbx_cursor_set(&mc, key, data, MDB_SET, &exact); } /** Find a sibling for a page. * Replaces the page at the top of the cursor's stack with the * specified sibling, if one exists. * @param[in] mc The cursor for this operation. * @param[in] move_right Non-zero if the right sibling is requested, * otherwise the left sibling. * @return 0 on success, non-zero on failure. */ static int mdbx_cursor_sibling(MDB_cursor *mc, int move_right) { int rc; MDB_node *indx; MDB_page *mp; if (unlikely(mc->mc_snum < 2)) { return MDB_NOTFOUND; /* root has no siblings */ } mdbx_cursor_pop(mc); mdbx_debug("parent page is page %zu, index %u", mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]); if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top])) : (mc->mc_ki[mc->mc_top] == 0)) { mdbx_debug("no more keys left, moving to %s sibling", move_right ? "right" : "left"); if (unlikely((rc = mdbx_cursor_sibling(mc, move_right)) != MDB_SUCCESS)) { /* undo cursor_pop before returning */ mc->mc_top++; mc->mc_snum++; return rc; } } else { if (move_right) mc->mc_ki[mc->mc_top]++; else mc->mc_ki[mc->mc_top]--; mdbx_debug("just moving to %s index key %u", move_right ? "right" : "left", mc->mc_ki[mc->mc_top]); } mdbx_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top])); indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (unlikely((rc = mdbx_page_get(mc, NODEPGNO(indx), &mp, NULL)) != 0)) { /* mc will be inconsistent if caller does mc_snum++ as above */ mc->mc_flags &= ~(C_INITIALIZED | C_EOF); return rc; } mdbx_cursor_push(mc, mp); if (!move_right) mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1; return MDB_SUCCESS; } /** Move the cursor to the next data item. */ static int mdbx_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { MDB_page *mp; MDB_node *leaf; int rc; if ((mc->mc_flags & C_DEL) && op == MDB_NEXT_DUP) return MDB_NOTFOUND; if (!(mc->mc_flags & C_INITIALIZED)) return mdbx_cursor_first(mc, key, data); mp = mc->mc_pg[mc->mc_top]; if (mc->mc_flags & C_EOF) { if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) return MDB_NOTFOUND; mc->mc_flags ^= C_EOF; } if (mc->mc_db->md_flags & MDB_DUPSORT) { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_NEXT || op == MDB_NEXT_DUP) { rc = mdbx_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT); if (op != MDB_NEXT || rc != MDB_NOTFOUND) { if (likely(rc == MDB_SUCCESS)) MDB_GET_KEY(leaf, key); return rc; } } } else { mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF); if (op == MDB_NEXT_DUP) return MDB_NOTFOUND; } } mdbx_debug("cursor_next: top page is %zu in cursor %p", mdbx_dbg_pgno(mp), (void *)mc); if (mc->mc_flags & C_DEL) { mc->mc_flags ^= C_DEL; goto skip; } if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) { mdbx_debug("=====> move to next sibling page"); if (unlikely((rc = mdbx_cursor_sibling(mc, 1)) != MDB_SUCCESS)) { mc->mc_flags |= C_EOF; return rc; } mp = mc->mc_pg[mc->mc_top]; mdbx_debug("next page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]); } else mc->mc_ki[mc->mc_top]++; skip: mdbx_debug("==> cursor points to page %zu with %u keys, key index %u", mdbx_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]); if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_xsize; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } mdbx_cassert(mc, IS_LEAF(mp)); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_xcursor_init1(mc, leaf); } if (data) { if (unlikely((rc = mdbx_node_read(mc, leaf, data)) != MDB_SUCCESS)) return rc; if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); if (unlikely(rc != MDB_SUCCESS)) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } /** Move the cursor to the previous data item. */ static int mdbx_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { MDB_page *mp; MDB_node *leaf; int rc; if ((mc->mc_flags & C_DEL) && op == MDB_PREV_DUP) return MDB_NOTFOUND; if (!(mc->mc_flags & C_INITIALIZED)) { rc = mdbx_cursor_last(mc, key, data); if (unlikely(rc)) return rc; mc->mc_ki[mc->mc_top]++; } mp = mc->mc_pg[mc->mc_top]; if ((mc->mc_db->md_flags & MDB_DUPSORT) && mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_PREV || op == MDB_PREV_DUP) { rc = mdbx_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV); if (op != MDB_PREV || rc != MDB_NOTFOUND) { if (likely(rc == MDB_SUCCESS)) { MDB_GET_KEY(leaf, key); mc->mc_flags &= ~C_EOF; } return rc; } } } else { mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF); if (op == MDB_PREV_DUP) return MDB_NOTFOUND; } } mdbx_debug("cursor_prev: top page is %zu in cursor %p", mdbx_dbg_pgno(mp), (void *)mc); mc->mc_flags &= ~(C_EOF | C_DEL); if (mc->mc_ki[mc->mc_top] == 0) { mdbx_debug("=====> move to prev sibling page"); if ((rc = mdbx_cursor_sibling(mc, 0)) != MDB_SUCCESS) { return rc; } mp = mc->mc_pg[mc->mc_top]; mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1; mdbx_debug("prev page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]); } else mc->mc_ki[mc->mc_top]--; mdbx_debug("==> cursor points to page %zu with %u keys, key index %u", mdbx_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]); if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_xsize; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } mdbx_cassert(mc, IS_LEAF(mp)); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_xcursor_init1(mc, leaf); } if (data) { if (unlikely((rc = mdbx_node_read(mc, leaf, data)) != MDB_SUCCESS)) return rc; if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { rc = mdbx_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); if (unlikely(rc != MDB_SUCCESS)) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } /** Set the cursor on a specific data item. */ static int mdbx_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp) { int rc; MDB_page *mp; MDB_node *leaf = NULL; DKBUF; if ((mc->mc_db->md_flags & MDB_INTEGERKEY) && unlikely(key->mv_size != sizeof(unsigned) && key->mv_size != sizeof(size_t))) { mdbx_cassert(mc, !"key-size is invalid for MDB_INTEGERKEY"); return MDB_BAD_VALSIZE; } if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF); /* See if we're already on the right page */ if (mc->mc_flags & C_INITIALIZED) { MDB_val nodekey; mp = mc->mc_pg[mc->mc_top]; if (!NUMKEYS(mp)) { mc->mc_ki[mc->mc_top] = 0; return MDB_NOTFOUND; } if (mp->mp_flags & P_LEAF2) { nodekey.mv_size = mc->mc_db->md_xsize; nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size); } else { leaf = NODEPTR(mp, 0); MDB_GET_KEY2(leaf, nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* Probably happens rarely, but first node on the page * was the one we wanted. */ mc->mc_ki[mc->mc_top] = 0; if (exactp) *exactp = 1; goto set1; } if (rc > 0) { unsigned i; unsigned nkeys = NUMKEYS(mp); if (nkeys > 1) { if (mp->mp_flags & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, nkeys - 1, nodekey.mv_size); } else { leaf = NODEPTR(mp, nkeys - 1); MDB_GET_KEY2(leaf, nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* last node was the one we wanted */ mc->mc_ki[mc->mc_top] = nkeys - 1; if (exactp) *exactp = 1; goto set1; } if (rc < 0) { if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) { /* This is definitely the right page, skip search_page */ if (mp->mp_flags & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], nodekey.mv_size); } else { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); MDB_GET_KEY2(leaf, nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* current node was the one we wanted */ if (exactp) *exactp = 1; goto set1; } } rc = 0; mc->mc_flags &= ~C_EOF; goto set2; } } /* If any parents have right-sibs, search. * Otherwise, there's nothing further. */ for (i = 0; i < mc->mc_top; i++) if (mc->mc_ki[i] < NUMKEYS(mc->mc_pg[i]) - 1) break; if (i == mc->mc_top) { /* There are no other pages */ mc->mc_ki[mc->mc_top] = nkeys; return MDB_NOTFOUND; } } if (!mc->mc_top) { /* There are no other pages */ mc->mc_ki[mc->mc_top] = 0; if (op == MDB_SET_RANGE && !exactp) { rc = 0; goto set1; } else return MDB_NOTFOUND; } } else { mc->mc_pg[0] = 0; } rc = mdbx_page_search(mc, key, 0); if (unlikely(rc != MDB_SUCCESS)) return rc; mp = mc->mc_pg[mc->mc_top]; mdbx_cassert(mc, IS_LEAF(mp)); set2: leaf = mdbx_node_search(mc, key, exactp); if (exactp != NULL && !*exactp) { /* MDB_SET specified and not an exact match. */ return MDB_NOTFOUND; } if (leaf == NULL) { mdbx_debug("===> inexact leaf not found, goto sibling"); if (unlikely((rc = mdbx_cursor_sibling(mc, 1)) != MDB_SUCCESS)) { mc->mc_flags |= C_EOF; return rc; /* no entries matched */ } mp = mc->mc_pg[mc->mc_top]; mdbx_cassert(mc, IS_LEAF(mp)); leaf = NODEPTR(mp, 0); } set1: mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; if (IS_LEAF2(mp)) { if (op == MDB_SET_RANGE || op == MDB_SET_KEY) { key->mv_size = mc->mc_db->md_xsize; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); } return MDB_SUCCESS; } if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_xcursor_init1(mc, leaf); } if (likely(data)) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) { rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); } else { int ex2, *ex2p; if (op == MDB_GET_BOTH) { ex2p = &ex2; ex2 = 0; } else { ex2p = NULL; } rc = mdbx_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p); if (unlikely(rc != MDB_SUCCESS)) return rc; } } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) { MDB_val olddata; if (unlikely((rc = mdbx_node_read(mc, leaf, &olddata)) != MDB_SUCCESS)) return rc; rc = mc->mc_dbx->md_dcmp(data, &olddata); if (rc) { if (op == MDB_GET_BOTH || rc > 0) return MDB_NOTFOUND; rc = 0; } *data = olddata; } else { if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF); if (unlikely((rc = mdbx_node_read(mc, leaf, data)) != MDB_SUCCESS)) return rc; } } /* The key already matches in all other cases */ if (op == MDB_SET_RANGE || op == MDB_SET_KEY) MDB_GET_KEY(leaf, key); mdbx_debug("==> cursor placed on key [%s]", DKEY(key)); return rc; } /** Move the cursor to the first item in the database. */ static int mdbx_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data) { int rc; MDB_node *leaf; if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF); if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { rc = mdbx_page_search(mc, NULL, MDB_PS_FIRST); if (unlikely(rc != MDB_SUCCESS)) return rc; } mdbx_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top])); leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0); mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; mc->mc_ki[mc->mc_top] = 0; if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { key->mv_size = mc->mc_db->md_xsize; key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size); return MDB_SUCCESS; } if (likely(data)) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_xcursor_init1(mc, leaf); rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); if (unlikely(rc)) return rc; } else { if (unlikely((rc = mdbx_node_read(mc, leaf, data)) != MDB_SUCCESS)) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } /** Move the cursor to the last item in the database. */ static int mdbx_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data) { int rc; MDB_node *leaf; if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF); if (likely((mc->mc_flags & (C_EOF | C_DEL)) != C_EOF)) { if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { rc = mdbx_page_search(mc, NULL, MDB_PS_LAST); if (unlikely(rc != MDB_SUCCESS)) return rc; } mdbx_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top])); } mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1; mc->mc_flags |= C_INITIALIZED | C_EOF; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { key->mv_size = mc->mc_db->md_xsize; key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } if (likely(data)) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_xcursor_init1(mc, leaf); rc = mdbx_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); if (unlikely(rc)) return rc; } else { if (unlikely((rc = mdbx_node_read(mc, leaf, data)) != MDB_SUCCESS)) return rc; } } MDB_GET_KEY(leaf, key); return MDB_SUCCESS; } int mdbx_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { int rc; int exact = 0; int (*mfunc)(MDB_cursor * mc, MDB_val * key, MDB_val * data); if (unlikely(mc == NULL)) return EINVAL; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; switch (op) { case MDB_GET_CURRENT: { if (unlikely(!(mc->mc_flags & C_INITIALIZED))) return EINVAL; MDB_page *mp = mc->mc_pg[mc->mc_top]; unsigned nkeys = NUMKEYS(mp); if (mc->mc_ki[mc->mc_top] >= nkeys) { mc->mc_ki[mc->mc_top] = nkeys; return MDB_NOTFOUND; } assert(nkeys > 0); rc = MDB_SUCCESS; if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_xsize; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); } else { MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); MDB_GET_KEY(leaf, key); if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (unlikely(!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))) { mdbx_xcursor_init1(mc, leaf); rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); if (unlikely(rc)) return rc; } rc = mdbx_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT); } else { rc = mdbx_node_read(mc, leaf, data); } if (unlikely(rc)) return rc; } } break; } case MDB_GET_BOTH: case MDB_GET_BOTH_RANGE: if (unlikely(data == NULL)) return EINVAL; if (unlikely(mc->mc_xcursor == NULL)) return MDB_INCOMPATIBLE; /* FALLTHRU */ case MDB_SET: case MDB_SET_KEY: case MDB_SET_RANGE: if (unlikely(key == NULL)) return EINVAL; rc = mdbx_cursor_set(mc, key, data, op, op == MDB_SET_RANGE ? NULL : &exact); break; case MDB_GET_MULTIPLE: if (unlikely(data == NULL || !(mc->mc_flags & C_INITIALIZED))) return EINVAL; if (unlikely(!(mc->mc_db->md_flags & MDB_DUPFIXED))) return MDB_INCOMPATIBLE; rc = MDB_SUCCESS; if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) || (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF)) break; goto fetchm; case MDB_NEXT_MULTIPLE: if (unlikely(data == NULL)) return EINVAL; if (unlikely(!(mc->mc_db->md_flags & MDB_DUPFIXED))) return MDB_INCOMPATIBLE; rc = mdbx_cursor_next(mc, key, data, MDB_NEXT_DUP); if (rc == MDB_SUCCESS) { if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) { MDB_cursor *mx; fetchm: mx = &mc->mc_xcursor->mx_cursor; data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) * mx->mc_db->md_xsize; data->mv_data = PAGEDATA(mx->mc_pg[mx->mc_top]); mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top]) - 1; } else { rc = MDB_NOTFOUND; } } break; case MDB_PREV_MULTIPLE: if (data == NULL) return EINVAL; if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) return MDB_INCOMPATIBLE; rc = MDB_SUCCESS; if (!(mc->mc_flags & C_INITIALIZED)) rc = mdbx_cursor_last(mc, key, data); if (rc == MDB_SUCCESS) { MDB_cursor *mx = &mc->mc_xcursor->mx_cursor; if (mx->mc_flags & C_INITIALIZED) { rc = mdbx_cursor_sibling(mx, 0); if (rc == MDB_SUCCESS) goto fetchm; } else { rc = MDB_NOTFOUND; } } break; case MDB_NEXT: case MDB_NEXT_DUP: case MDB_NEXT_NODUP: rc = mdbx_cursor_next(mc, key, data, op); break; case MDB_PREV: case MDB_PREV_DUP: case MDB_PREV_NODUP: rc = mdbx_cursor_prev(mc, key, data, op); break; case MDB_FIRST: rc = mdbx_cursor_first(mc, key, data); break; case MDB_FIRST_DUP: mfunc = mdbx_cursor_first; mmove: if (unlikely(data == NULL || !(mc->mc_flags & C_INITIALIZED))) return EINVAL; if (unlikely(mc->mc_xcursor == NULL)) return MDB_INCOMPATIBLE; { MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { MDB_GET_KEY(leaf, key); rc = mdbx_node_read(mc, leaf, data); break; } } if (unlikely(!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))) return EINVAL; rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL); break; case MDB_LAST: rc = mdbx_cursor_last(mc, key, data); break; case MDB_LAST_DUP: mfunc = mdbx_cursor_last; goto mmove; default: mdbx_debug("unhandled/unimplemented cursor operation %u", op); return EINVAL; } mc->mc_flags &= ~C_DEL; return rc; } /** Touch all the pages in the cursor stack. Set mc_top. * Makes sure all the pages are writable, before attempting a write *operation. * @param[in] mc The cursor to operate on. */ static int mdbx_cursor_touch(MDB_cursor *mc) { int rc = MDB_SUCCESS; if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & (DB_DIRTY | DB_DUPDATA))) { /* Touch DB record of named DB */ MDB_cursor mc2; MDB_xcursor mcx; if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi)) return MDB_BAD_DBI; mdbx_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx); rc = mdbx_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY); if (unlikely(rc)) return rc; *mc->mc_dbflag |= DB_DIRTY; } mc->mc_top = 0; if (mc->mc_snum) { do { rc = mdbx_page_touch(mc); } while (!rc && ++(mc->mc_top) < mc->mc_snum); mc->mc_top = mc->mc_snum - 1; } return rc; } /** Do not spill pages to disk if txn is getting full, may fail instead */ #define MDB_NOSPILL 0x8000 int mdbx_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data, unsigned flags) { MDB_env *env; MDB_node *leaf = NULL; MDB_page *fp, *mp, *sub_root = NULL; uint16_t fp_flags; MDB_val xdata, *rdata, dkey, olddata; MDB_db dummy; int do_sub = 0, insert_key, insert_data; unsigned mcount = 0, dcount = 0, nospill; size_t nsize; int rc, rc2; unsigned nflags; DKBUF; if (unlikely(mc == NULL || key == NULL)) return EINVAL; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE)) return MDBX_EBADSIGN; env = mc->mc_txn->mt_env; /* Check this first so counter will always be zero on any * early failures. */ if (flags & MDB_MULTIPLE) { dcount = data[1].mv_size; data[1].mv_size = 0; if (unlikely(!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))) return MDB_INCOMPATIBLE; } if (flags & MDB_RESERVE) { if (unlikely(mc->mc_db->md_flags & (MDB_DUPSORT | MDB_REVERSEDUP))) return MDB_INCOMPATIBLE; } nospill = flags & MDB_NOSPILL; flags &= ~MDB_NOSPILL; if (unlikely(mc->mc_txn->mt_flags & (MDB_TXN_RDONLY | MDB_TXN_BLOCKED))) return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; if (unlikely(key->mv_size > ENV_MAXKEY(env))) return MDB_BAD_VALSIZE; #if SIZE_MAX > MAXDATASIZE if (unlikely(data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))) return MDB_BAD_VALSIZE; #else if ((mc->mc_db->md_flags & MDB_DUPSORT) && unlikely(data->mv_size > ENV_MAXKEY(env))) return MDB_BAD_VALSIZE; #endif if ((mc->mc_db->md_flags & MDB_INTEGERKEY) && unlikely(key->mv_size != sizeof(unsigned) && key->mv_size != sizeof(size_t))) { mdbx_cassert(mc, !"key-size is invalid for MDB_INTEGERKEY"); return MDB_BAD_VALSIZE; } if ((mc->mc_db->md_flags & MDB_INTEGERDUP) && unlikely(data->mv_size != sizeof(unsigned) && data->mv_size != sizeof(size_t))) { mdbx_cassert(mc, !"data-size is invalid MDB_INTEGERDUP"); return MDB_BAD_VALSIZE; } mdbx_debug("==> put db %d key [%s], size %zu, data size %zu", DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size); int dupdata_flag = 0; if (flags & MDB_CURRENT) { if (unlikely(!(mc->mc_flags & C_INITIALIZED))) return EINVAL; #if MDBX_MODE_ENABLED if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) { MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_cassert(mc, mc->mc_xcursor != NULL && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)); if (mc->mc_xcursor->mx_db.md_entries > 1) { rc = mdbx_cursor_del(mc, 0); if (rc != MDB_SUCCESS) return rc; flags -= MDB_CURRENT; } } } #endif /* MDBX_MODE_ENABLED */ rc = MDB_SUCCESS; } else if (mc->mc_db->md_root == P_INVALID) { /* new database, cursor has nothing to point to */ mc->mc_snum = 0; mc->mc_top = 0; mc->mc_flags &= ~C_INITIALIZED; rc = MDB_NO_ROOT; } else { int exact = 0; MDB_val d2; if (flags & MDB_APPEND) { MDB_val k2; rc = mdbx_cursor_last(mc, &k2, &d2); if (rc == 0) { rc = mc->mc_dbx->md_cmp(key, &k2); if (rc > 0) { rc = MDB_NOTFOUND; mc->mc_ki[mc->mc_top]++; } else { /* new key is <= last key */ rc = MDB_KEYEXIST; } } } else { rc = mdbx_cursor_set(mc, key, &d2, MDB_SET, &exact); } if ((flags & MDB_NOOVERWRITE) && rc == 0) { mdbx_debug("duplicate key [%s]", DKEY(key)); *data = d2; return MDB_KEYEXIST; } if (rc && unlikely(rc != MDB_NOTFOUND)) return rc; } mc->mc_flags &= ~C_DEL; /* Cursor is positioned, check for room in the dirty list */ if (!nospill) { if (flags & MDB_MULTIPLE) { rdata = &xdata; xdata.mv_size = data->mv_size * dcount; } else { rdata = data; } if (unlikely(rc2 = mdbx_page_spill(mc, key, rdata))) return rc2; } if (rc == MDB_NO_ROOT) { MDB_page *np; /* new database, write a root leaf page */ mdbx_debug("allocating new root leaf page"); if (unlikely(rc2 = mdbx_page_new(mc, P_LEAF, 1, &np))) { return rc2; } mdbx_cursor_push(mc, np); mc->mc_db->md_root = np->mp_pgno; mc->mc_db->md_depth++; *mc->mc_dbflag |= DB_DIRTY; if ((mc->mc_db->md_flags & (MDB_DUPSORT | MDB_DUPFIXED)) == MDB_DUPFIXED) np->mp_flags |= P_LEAF2; mc->mc_flags |= C_INITIALIZED; } else { /* make sure all cursor pages are writable */ rc2 = mdbx_cursor_touch(mc); if (unlikely(rc2)) return rc2; } insert_key = insert_data = rc; if (insert_key) { /* The key does not exist */ mdbx_debug("inserting key at index %i", mc->mc_ki[mc->mc_top]); if ((mc->mc_db->md_flags & MDB_DUPSORT) && LEAFSIZE(key, data) > env->me_nodemax) { /* Too big for a node, insert in sub-DB. Set up an empty * "old sub-page" for prep_subDB to expand to a full page. */ fp_flags = P_LEAF | P_DIRTY; fp = env->me_pbuf; fp->mp_leaf2_ksize = data->mv_size; /* used if MDB_DUPFIXED */ fp->mp_lower = fp->mp_upper = (PAGEHDRSZ - PAGEBASE); olddata.mv_size = PAGEHDRSZ; goto prep_subDB; } } else { /* there's only a key anyway, so this is a no-op */ if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { char *ptr; unsigned ksize = mc->mc_db->md_xsize; if (key->mv_size != ksize) return MDB_BAD_VALSIZE; ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize); memcpy(ptr, key->mv_data, ksize); fix_parent: /* if overwriting slot 0 of leaf, need to * update branch key if there is a parent page */ if (mc->mc_top && !mc->mc_ki[mc->mc_top]) { unsigned short dtop = 1; mc->mc_top--; /* slot 0 is always an empty key, find real slot */ while (mc->mc_top && !mc->mc_ki[mc->mc_top]) { mc->mc_top--; dtop++; } if (mc->mc_ki[mc->mc_top]) rc2 = mdbx_update_key(mc, key); else rc2 = MDB_SUCCESS; mc->mc_top += dtop; if (rc2) return rc2; } return MDB_SUCCESS; } more: leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); olddata.mv_size = NODEDSZ(leaf); olddata.mv_data = NODEDATA(leaf); /* DB has dups? */ if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) { /* Prepare (sub-)page/sub-DB to accept the new item, * if needed. fp: old sub-page or a header faking * it. mp: new (sub-)page. offset: growth in page * size. xdata: node data with new page or DB. */ unsigned i, offset = 0; mp = fp = xdata.mv_data = env->me_pbuf; mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno; /* Was a single item before, must convert now */ if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { /* Just overwrite the current item */ if (flags & MDB_CURRENT) { if ((flags & MDB_NODUPDATA) && !mc->mc_dbx->md_dcmp(data, &olddata)) return MDB_KEYEXIST; goto current; } /* does data match? */ if (!mc->mc_dbx->md_dcmp(data, &olddata)) { if (unlikely(flags & (MDB_NODUPDATA | MDB_APPENDDUP))) return MDB_KEYEXIST; /* overwrite it */ goto current; } /* Back up original data item */ dupdata_flag = 1; dkey.mv_size = olddata.mv_size; dkey.mv_data = memcpy(fp + 1, olddata.mv_data, olddata.mv_size); /* Make sub-page header for the dup items, with dummy body */ fp->mp_flags = P_LEAF | P_DIRTY | P_SUBP; fp->mp_lower = (PAGEHDRSZ - PAGEBASE); xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size; if (mc->mc_db->md_flags & MDB_DUPFIXED) { fp->mp_flags |= P_LEAF2; fp->mp_leaf2_ksize = data->mv_size; xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */ } else { xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) + (dkey.mv_size & 1) + (data->mv_size & 1); } fp->mp_upper = xdata.mv_size - PAGEBASE; olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */ } else if (leaf->mn_flags & F_SUBDATA) { /* Data is on sub-DB, just store it */ flags |= F_DUPDATA | F_SUBDATA; goto put_sub; } else { /* Data is on sub-page */ fp = olddata.mv_data; switch (flags) { default: if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) { offset = EVEN(NODESIZE + sizeof(indx_t) + data->mv_size); break; } offset = fp->mp_leaf2_ksize; if (SIZELEFT(fp) < offset) { offset *= 4; /* space for 4 more */ break; } /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */ case MDB_CURRENT | MDB_NODUPDATA: case MDB_CURRENT: fp->mp_flags |= P_DIRTY; COPY_PGNO(fp->mp_pgno, mp->mp_pgno); mc->mc_xcursor->mx_cursor.mc_pg[0] = fp; flags |= F_DUPDATA; goto put_sub; } xdata.mv_size = olddata.mv_size + offset; } fp_flags = fp->mp_flags; if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) { /* Too big for a sub-page, convert to sub-DB */ fp_flags &= ~P_SUBP; prep_subDB: if (mc->mc_db->md_flags & MDB_DUPFIXED) { fp_flags |= P_LEAF2; dummy.md_xsize = fp->mp_leaf2_ksize; dummy.md_flags = MDB_DUPFIXED; if (mc->mc_db->md_flags & MDB_INTEGERDUP) dummy.md_flags |= MDB_INTEGERKEY; } else { dummy.md_xsize = 0; dummy.md_flags = 0; } dummy.md_depth = 1; dummy.md_branch_pages = 0; dummy.md_leaf_pages = 1; dummy.md_overflow_pages = 0; dummy.md_entries = NUMKEYS(fp); xdata.mv_size = sizeof(MDB_db); xdata.mv_data = &dummy; if ((rc = mdbx_page_alloc(mc, 1, &mp, MDBX_ALLOC_ALL))) return rc; offset = env->me_psize - olddata.mv_size; flags |= F_DUPDATA | F_SUBDATA; dummy.md_root = mp->mp_pgno; sub_root = mp; } if (mp != fp) { mp->mp_flags = fp_flags | P_DIRTY; mp->mp_leaf2_ksize = fp->mp_leaf2_ksize; mp->mp_lower = fp->mp_lower; mp->mp_upper = fp->mp_upper + offset; if (fp_flags & P_LEAF2) { memcpy(PAGEDATA(mp), PAGEDATA(fp), NUMKEYS(fp) * fp->mp_leaf2_ksize); } else { memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE, olddata.mv_size - fp->mp_upper - PAGEBASE); for (i = 0; i < NUMKEYS(fp); i++) mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset; } } rdata = &xdata; flags |= F_DUPDATA; do_sub = 1; if (!insert_key) mdbx_node_del(mc, 0); goto new_sub; } current: /* LMDB passes F_SUBDATA in 'flags' to write a DB record */ if (unlikely((leaf->mn_flags ^ flags) & F_SUBDATA)) return MDB_INCOMPATIBLE; /* overflow page overwrites need special handling */ if (F_ISSET(leaf->mn_flags, F_BIGDATA)) { MDB_page *omp; pgno_t pg; int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize); memcpy(&pg, olddata.mv_data, sizeof(pg)); if (unlikely((rc2 = mdbx_page_get(mc, pg, &omp, &level)) != 0)) return rc2; ovpages = omp->mp_pages; /* Is the ov page large enough? */ if (ovpages >= dpages) { if (!(omp->mp_flags & P_DIRTY) && (level || (env->me_flags & MDB_WRITEMAP))) { rc = mdbx_page_unspill(mc->mc_txn, omp, &omp); if (unlikely(rc)) return rc; level = 0; /* dirty in this txn or clean */ } /* Is it dirty? */ if (omp->mp_flags & P_DIRTY) { /* yes, overwrite it. Note in this case we don't * bother to try shrinking the page if the new data * is smaller than the overflow threshold. */ if (unlikely(level > 1)) { /* It is writable only in a parent txn */ MDB_page *np = mdbx_page_malloc(mc->mc_txn, ovpages); MDB_ID2 id2; if (unlikely(!np)) return ENOMEM; id2.mid = pg; id2.mptr = np; /* Note - this page is already counted in parent's dirty_room */ rc2 = mdbx_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2); mdbx_cassert(mc, rc2 == 0); /* Currently we make the page look as with put() in the * parent txn, in case the user peeks at MDB_RESERVEd * or unused parts. Some users treat ovpages specially. */ size_t sz = (size_t)env->me_psize * ovpages, off; if (MDBX_MODE_ENABLED || !(flags & MDB_RESERVE)) { /* Skip the part where LMDB will put *data. * Copy end of page, adjusting alignment so * compiler may copy words instead of bytes. */ off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t); memcpy((size_t *)((char *)np + off), (size_t *)((char *)omp + off), sz - off); sz = PAGEHDRSZ; } memcpy(np, omp, sz); /* Copy whole or header of page */ omp = np; } SETDSZ(leaf, data->mv_size); if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = PAGEDATA(omp); else memcpy(PAGEDATA(omp), data->mv_data, data->mv_size); return MDB_SUCCESS; } } if ((rc2 = mdbx_ovpage_free(mc, omp)) != MDB_SUCCESS) return rc2; } else if (data->mv_size == olddata.mv_size) { /* same size, just replace it. Note that we could * also reuse this node if the new data is smaller, * but instead we opt to shrink the node in that case. */ if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = olddata.mv_data; else if (!(mc->mc_flags & C_SUB)) memcpy(olddata.mv_data, data->mv_data, data->mv_size); else { memcpy(NODEKEY(leaf), key->mv_data, key->mv_size); goto fix_parent; } return MDB_SUCCESS; } mdbx_node_del(mc, 0); } rdata = data; new_sub: nflags = flags & NODE_ADD_FLAGS; nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdbx_leaf_size(env, key, rdata); if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) { if ((flags & (F_DUPDATA | F_SUBDATA)) == F_DUPDATA) nflags &= ~MDB_APPEND; /* sub-page may need room to grow */ if (!insert_key) nflags |= MDB_SPLIT_REPLACE; rc = mdbx_page_split(mc, key, rdata, P_INVALID, nflags); } else { /* There is room already in this leaf page. */ rc = mdbx_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags); if (likely(rc == 0)) { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; unsigned i = mc->mc_top; MDB_page *mp = mc->mc_pg[i]; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp) continue; if (m3->mc_ki[i] >= mc->mc_ki[i] && insert_key) { m3->mc_ki[i]++; } if (XCURSOR_INITED(m3)) XCURSOR_REFRESH(m3, mp, m3->mc_ki[i]); } } } if (likely(rc == MDB_SUCCESS)) { /* Now store the actual data in the child DB. Note that we're * storing the user data in the keys field, so there are strict * size limits on dupdata. The actual data fields of the child * DB are all zero size. */ if (do_sub) { int xflags; size_t ecount; put_sub: xdata.mv_size = 0; xdata.mv_data = ""; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (flags & MDB_CURRENT) { xflags = (flags & MDB_NODUPDATA) ? MDB_CURRENT | MDB_NOOVERWRITE | MDB_NOSPILL : MDB_CURRENT | MDB_NOSPILL; } else { mdbx_xcursor_init1(mc, leaf); xflags = (flags & MDB_NODUPDATA) ? MDB_NOOVERWRITE | MDB_NOSPILL : MDB_NOSPILL; } if (sub_root) mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root; /* converted, write the original data first */ if (dupdata_flag) { rc = mdbx_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags); if (unlikely(rc)) goto bad_sub; /* we've done our job */ dkey.mv_size = 0; } if (!(leaf->mn_flags & F_SUBDATA) || sub_root) { /* Adjust other cursors pointing to mp */ MDB_cursor *m2; MDB_xcursor *mx = mc->mc_xcursor; unsigned i = mc->mc_top; MDB_page *mp = mc->mc_pg[i]; int nkeys = NUMKEYS(mp); for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2 = m2->mc_next) { if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; if (!(m2->mc_flags & C_INITIALIZED)) continue; if (m2->mc_pg[i] == mp) { if (m2->mc_ki[i] == mc->mc_ki[i]) { mdbx_xcursor_init2(m2, mx, dupdata_flag); } else if (!insert_key && m2->mc_ki[i] < nkeys) { XCURSOR_REFRESH(m2, mp, m2->mc_ki[i]); } } } } ecount = mc->mc_xcursor->mx_db.md_entries; if (flags & MDB_APPENDDUP) xflags |= MDB_APPEND; rc = mdbx_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags); if (flags & F_SUBDATA) { void *db = NODEDATA(leaf); memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); } insert_data = mc->mc_xcursor->mx_db.md_entries - ecount; } /* Increment count unless we just replaced an existing item. */ if (insert_data) mc->mc_db->md_entries++; if (insert_key) { /* Invalidate txn if we created an empty sub-DB */ if (unlikely(rc)) goto bad_sub; /* If we succeeded and the key didn't exist before, * make sure the cursor is marked valid. */ mc->mc_flags |= C_INITIALIZED; } if (flags & MDB_MULTIPLE) { if (!rc) { mcount++; /* let caller know how many succeeded, if any */ data[1].mv_size = mcount; if (mcount < dcount) { data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size; insert_key = insert_data = 0; goto more; } } } return rc; bad_sub: if (unlikely(rc == MDB_KEYEXIST)) /* should not happen, we deleted that item */ rc = MDB_PROBLEM; } mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdbx_cursor_del(MDB_cursor *mc, unsigned flags) { MDB_node *leaf; MDB_page *mp; int rc; if (unlikely(!mc)) return EINVAL; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(mc->mc_txn->mt_flags & (MDB_TXN_RDONLY | MDB_TXN_BLOCKED))) return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; if (unlikely(!(mc->mc_flags & C_INITIALIZED))) return EINVAL; if (unlikely(mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))) return MDB_NOTFOUND; if (unlikely(!(flags & MDB_NOSPILL) && (rc = mdbx_page_spill(mc, NULL, NULL)))) return rc; rc = mdbx_cursor_touch(mc); if (unlikely(rc)) return rc; mp = mc->mc_pg[mc->mc_top]; if (IS_LEAF2(mp)) goto del_key; leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (flags & MDB_NODUPDATA) { /* mdbx_cursor_del0() will subtract the final entry */ mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1; mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; } else { if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) { mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); } rc = mdbx_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL); if (unlikely(rc)) return rc; /* If sub-DB still has entries, we're done */ if (mc->mc_xcursor->mx_db.md_entries) { if (leaf->mn_flags & F_SUBDATA) { /* update subDB info */ void *db = NODEDATA(leaf); memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); } else { MDB_cursor *m2; /* shrink fake page */ mdbx_node_shrink(mp, mc->mc_ki[mc->mc_top]); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); /* fix other sub-DB cursors pointed at fake pages on this page */ for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2 = m2->mc_next) { if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; if (!(m2->mc_flags & C_INITIALIZED)) continue; if (m2->mc_pg[mc->mc_top] == mp) { MDB_node *n2 = leaf; if (m2->mc_ki[mc->mc_top] != mc->mc_ki[mc->mc_top]) { n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]); if (n2->mn_flags & F_SUBDATA) continue; } m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2); } } } mc->mc_db->md_entries--; return rc; } else { mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; } /* otherwise fall thru and delete the sub-DB */ } if (leaf->mn_flags & F_SUBDATA) { /* add all the child DB's pages to the free list */ rc = mdbx_drop0(&mc->mc_xcursor->mx_cursor, 0); if (unlikely(rc)) goto fail; } } /* LMDB passes F_SUBDATA in 'flags' to delete a DB record */ else if (unlikely((leaf->mn_flags ^ flags) & F_SUBDATA)) { rc = MDB_INCOMPATIBLE; goto fail; } /* add overflow pages to free list */ if (F_ISSET(leaf->mn_flags, F_BIGDATA)) { MDB_page *omp; pgno_t pg; memcpy(&pg, NODEDATA(leaf), sizeof(pg)); if (unlikely((rc = mdbx_page_get(mc, pg, &omp, NULL)) || (rc = mdbx_ovpage_free(mc, omp)))) goto fail; } del_key: return mdbx_cursor_del0(mc); fail: mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } /** Allocate and initialize new pages for a database. * Set #MDB_TXN_ERROR on failure. * @param[in] mc a cursor on the database being added to. * @param[in] flags flags defining what type of page is being allocated. * @param[in] num the number of pages to allocate. This is usually 1, * unless allocating overflow pages for a large record. * @param[out] mp Address of a page, or NULL on failure. * @return 0 on success, non-zero on failure. */ static int mdbx_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp) { MDB_page *np; int rc; if (unlikely((rc = mdbx_page_alloc(mc, num, &np, MDBX_ALLOC_ALL)))) return rc; mdbx_debug("allocated new mpage %zu, page size %u", np->mp_pgno, mc->mc_txn->mt_env->me_psize); np->mp_flags = flags | P_DIRTY; np->mp_lower = (PAGEHDRSZ - PAGEBASE); np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE; if (IS_BRANCH(np)) mc->mc_db->md_branch_pages++; else if (IS_LEAF(np)) mc->mc_db->md_leaf_pages++; else if (IS_OVERFLOW(np)) { mc->mc_db->md_overflow_pages += num; np->mp_pages = num; } *mp = np; return 0; } /** Calculate the size of a leaf node. * The size depends on the environment's page size; if a data item * is too large it will be put onto an overflow page and the node * size will only include the key and not the data. Sizes are always * rounded up to an even number of bytes, to guarantee 2-byte alignment * of the #MDB_node headers. * @param[in] env The environment handle. * @param[in] key The key for the node. * @param[in] data The data for the node. * @return The number of bytes needed to store the node. */ static MDBX_INLINE size_t mdbx_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data) { size_t sz; sz = LEAFSIZE(key, data); if (sz > env->me_nodemax) { /* put on overflow page */ sz -= data->mv_size - sizeof(pgno_t); } return EVEN(sz + sizeof(indx_t)); } /** Calculate the size of a branch node. * The size should depend on the environment's page size but since * we currently don't support spilling large keys onto overflow * pages, it's simply the size of the #MDB_node header plus the * size of the key. Sizes are always rounded up to an even number * of bytes, to guarantee 2-byte alignment of the #MDB_node headers. * @param[in] env The environment handle. * @param[in] key The key for the node. * @return The number of bytes needed to store the node. */ static MDBX_INLINE size_t mdbx_branch_size(MDB_env *env, MDB_val *key) { size_t sz; sz = INDXSIZE(key); if (unlikely(sz > env->me_nodemax)) { /* put on overflow page */ /* not implemented */ mdbx_assert_fail(env, "INDXSIZE(key) <= env->me_nodemax", __FUNCTION__, __LINE__); sz -= key->mv_size - sizeof(pgno_t); } return sz + sizeof(indx_t); } /** Add a node to the page pointed to by the cursor. * Set #MDB_TXN_ERROR on failure. * @param[in] mc The cursor for this operation. * @param[in] indx The index on the page where the new node should be added. * @param[in] key The key for the new node. * @param[in] data The data for the new node, if any. * @param[in] pgno The page number, if adding a branch node. * @param[in] flags Flags for the node. * @return 0 on success, non-zero on failure. Possible errors are: *
    *
  • ENOMEM - failed to allocate overflow pages for the node. *
  • MDB_PAGE_FULL - there is insufficient room in the page. This error * should never happen since all callers already calculate the * page's free space before calling this function. *
*/ static int mdbx_node_add(MDB_cursor *mc, indx_t indx, MDB_val *key, MDB_val *data, pgno_t pgno, unsigned flags) { unsigned i; size_t node_size = NODESIZE; ssize_t room; indx_t ofs; MDB_node *node; MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_page *ofp = NULL; /* overflow page */ void *ndata; DKBUF; mdbx_cassert(mc, mp->mp_upper >= mp->mp_lower); mdbx_debug("add to %s %spage %zu index %i, data size %zu key size %zu [%s]", IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "", mdbx_dbg_pgno(mp), indx, data ? data->mv_size : 0, key ? key->mv_size : 0, key ? DKEY(key) : "null"); if (IS_LEAF2(mp)) { mdbx_cassert(mc, key); /* Move higher keys up one slot. */ int ksize = mc->mc_db->md_xsize, dif; char *ptr = LEAF2KEY(mp, indx, ksize); dif = NUMKEYS(mp) - indx; if (dif > 0) memmove(ptr + ksize, ptr, dif * ksize); /* insert new key */ memcpy(ptr, key->mv_data, ksize); /* Just using these for counting */ mp->mp_lower += sizeof(indx_t); mp->mp_upper -= ksize - sizeof(indx_t); return MDB_SUCCESS; } room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t); if (key != NULL) node_size += key->mv_size; if (IS_LEAF(mp)) { mdbx_cassert(mc, key && data); if (unlikely(F_ISSET(flags, F_BIGDATA))) { /* Data already on overflow page. */ node_size += sizeof(pgno_t); } else if (unlikely(node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax)) { int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize); int rc; /* Put data on overflow page. */ mdbx_debug( "data size is %zu, node would be %zu, put data on overflow page", data->mv_size, node_size + data->mv_size); node_size = EVEN(node_size + sizeof(pgno_t)); if ((ssize_t)node_size > room) goto full; if ((rc = mdbx_page_new(mc, P_OVERFLOW, ovpages, &ofp))) return rc; mdbx_debug("allocated overflow page %zu", ofp->mp_pgno); flags |= F_BIGDATA; goto update; } else { node_size += data->mv_size; } } node_size = EVEN(node_size); if (unlikely((ssize_t)node_size > room)) goto full; update: /* Move higher pointers up one slot. */ for (i = NUMKEYS(mp); i > indx; i--) mp->mp_ptrs[i] = mp->mp_ptrs[i - 1]; /* Adjust free space offsets. */ ofs = mp->mp_upper - node_size; mdbx_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t)); mp->mp_ptrs[indx] = ofs; mp->mp_upper = ofs; mp->mp_lower += sizeof(indx_t); /* Write the node data. */ node = NODEPTR(mp, indx); node->mn_ksize = (key == NULL) ? 0 : key->mv_size; node->mn_flags = flags; if (IS_LEAF(mp)) SETDSZ(node, data->mv_size); else SETPGNO(node, pgno); if (key) memcpy(NODEKEY(node), key->mv_data, key->mv_size); if (IS_LEAF(mp)) { ndata = NODEDATA(node); if (unlikely(ofp == NULL)) { if (unlikely(F_ISSET(flags, F_BIGDATA))) memcpy(ndata, data->mv_data, sizeof(pgno_t)); else if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = ndata; else if (likely(ndata != data->mv_data)) memcpy(ndata, data->mv_data, data->mv_size); } else { memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t)); ndata = PAGEDATA(ofp); if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = ndata; else if (likely(ndata != data->mv_data)) memcpy(ndata, data->mv_data, data->mv_size); } } return MDB_SUCCESS; full: mdbx_debug("not enough room in page %zu, got %u ptrs", mdbx_dbg_pgno(mp), NUMKEYS(mp)); mdbx_debug("upper-lower = %u - %u = %zd", mp->mp_upper, mp->mp_lower, room); mdbx_debug("node size = %zu", node_size); mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return MDB_PAGE_FULL; } /** Delete the specified node from a page. * @param[in] mc Cursor pointing to the node to delete. * @param[in] ksize The size of a node. Only used if the page is * part of a #MDB_DUPFIXED database. */ static void mdbx_node_del(MDB_cursor *mc, int ksize) { MDB_page *mp = mc->mc_pg[mc->mc_top]; indx_t indx = mc->mc_ki[mc->mc_top]; unsigned sz; indx_t i, j, numkeys, ptr; MDB_node *node; char *base; mdbx_debug("delete node %u on %s page %zu", indx, IS_LEAF(mp) ? "leaf" : "branch", mdbx_dbg_pgno(mp)); numkeys = NUMKEYS(mp); mdbx_cassert(mc, indx < numkeys); if (IS_LEAF2(mp)) { int x = numkeys - 1 - indx; base = LEAF2KEY(mp, indx, ksize); if (x) memmove(base, base + ksize, x * ksize); mp->mp_lower -= sizeof(indx_t); mp->mp_upper += ksize - sizeof(indx_t); return; } node = NODEPTR(mp, indx); sz = NODESIZE + node->mn_ksize; if (IS_LEAF(mp)) { if (F_ISSET(node->mn_flags, F_BIGDATA)) sz += sizeof(pgno_t); else sz += NODEDSZ(node); } sz = EVEN(sz); ptr = mp->mp_ptrs[indx]; for (i = j = 0; i < numkeys; i++) { if (i != indx) { mp->mp_ptrs[j] = mp->mp_ptrs[i]; if (mp->mp_ptrs[i] < ptr) mp->mp_ptrs[j] += sz; j++; } } base = (char *)mp + mp->mp_upper + PAGEBASE; memmove(base + sz, base, ptr - mp->mp_upper); mp->mp_lower -= sizeof(indx_t); mp->mp_upper += sz; } /** Compact the main page after deleting a node on a subpage. * @param[in] mp The main page to operate on. * @param[in] indx The index of the subpage on the main page. */ static void mdbx_node_shrink(MDB_page *mp, indx_t indx) { MDB_node *node; MDB_page *sp, *xp; char *base; indx_t delta, nsize, len, ptr; int i; node = NODEPTR(mp, indx); sp = (MDB_page *)NODEDATA(node); delta = SIZELEFT(sp); nsize = NODEDSZ(node) - delta; /* Prepare to shift upward, set len = length(subpage part to shift) */ if (IS_LEAF2(sp)) { len = nsize; if (nsize & 1) return; /* do not make the node uneven-sized */ } else { xp = (MDB_page *)((char *)sp + delta); /* destination subpage */ for (i = NUMKEYS(sp); --i >= 0;) xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta; len = PAGEHDRSZ; } sp->mp_upper = sp->mp_lower; COPY_PGNO(sp->mp_pgno, mp->mp_pgno); SETDSZ(node, nsize); /* Shift upward */ base = (char *)mp + mp->mp_upper + PAGEBASE; memmove(base + delta, base, (char *)sp + len - base); ptr = mp->mp_ptrs[indx]; for (i = NUMKEYS(mp); --i >= 0;) { if (mp->mp_ptrs[i] <= ptr) mp->mp_ptrs[i] += delta; } mp->mp_upper += delta; } /** Initial setup of a sorted-dups cursor. * Sorted duplicates are implemented as a sub-database for the given key. * The duplicate data items are actually keys of the sub-database. * Operations on the duplicate data items are performed using a sub-cursor * initialized when the sub-database is first accessed. This function does * the preliminary setup of the sub-cursor, filling in the fields that * depend only on the parent DB. * @param[in] mc The main cursor whose sorted-dups cursor is to be * initialized. */ static void mdbx_xcursor_init0(MDB_cursor *mc) { MDB_xcursor *mx = mc->mc_xcursor; mx->mx_cursor.mc_xcursor = NULL; mx->mx_cursor.mc_txn = mc->mc_txn; mx->mx_cursor.mc_db = &mx->mx_db; mx->mx_cursor.mc_dbx = &mx->mx_dbx; mx->mx_cursor.mc_dbi = mc->mc_dbi; mx->mx_cursor.mc_dbflag = &mx->mx_dbflag; mx->mx_cursor.mc_snum = 0; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags = C_SUB; mx->mx_dbx.md_name.mv_size = 0; mx->mx_dbx.md_name.mv_data = NULL; mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp; mx->mx_dbx.md_dcmp = NULL; } /** Final setup of a sorted-dups cursor. * Sets up the fields that depend on the data from the main cursor. * @param[in] mc The main cursor whose sorted-dups cursor is to be *initialized. * @param[in] node The data containing the #MDB_db record for the * sorted-dup database. */ static void mdbx_xcursor_init1(MDB_cursor *mc, MDB_node *node) { MDB_xcursor *mx = mc->mc_xcursor; if (node->mn_flags & F_SUBDATA) { memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db)); mx->mx_cursor.mc_pg[0] = 0; mx->mx_cursor.mc_snum = 0; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags = C_SUB; } else { MDB_page *fp = NODEDATA(node); mx->mx_db.md_xsize = 0; mx->mx_db.md_flags = 0; mx->mx_db.md_depth = 1; mx->mx_db.md_branch_pages = 0; mx->mx_db.md_leaf_pages = 1; mx->mx_db.md_overflow_pages = 0; mx->mx_db.md_entries = NUMKEYS(fp); COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno); mx->mx_cursor.mc_snum = 1; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags = C_INITIALIZED | C_SUB; mx->mx_cursor.mc_pg[0] = fp; mx->mx_cursor.mc_ki[0] = 0; if (mc->mc_db->md_flags & MDB_DUPFIXED) { mx->mx_db.md_flags = MDB_DUPFIXED; mx->mx_db.md_xsize = fp->mp_leaf2_ksize; if (mc->mc_db->md_flags & MDB_INTEGERDUP) mx->mx_db.md_flags |= MDB_INTEGERKEY; } } mdbx_debug("Sub-db -%u root page %zu", mx->mx_cursor.mc_dbi, mx->mx_db.md_root); mx->mx_dbflag = DB_VALID | DB_USRVALID | DB_DUPDATA; /* #if UINT_MAX < SIZE_MAX if (mx->mx_dbx.md_cmp == mdbx_cmp_int && mx->mx_db.md_pad == sizeof(size_t)) mx->mx_dbx.md_cmp = mdbx_cmp_clong; #endif */ } /** Fixup a sorted-dups cursor due to underlying update. * Sets up some fields that depend on the data from the main cursor. * Almost the same as init1, but skips initialization steps if the * xcursor had already been used. * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up. * @param[in] src_mx The xcursor of an up-to-date cursor. * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item. */ static void mdbx_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata) { MDB_xcursor *mx = mc->mc_xcursor; if (new_dupdata) { mx->mx_cursor.mc_snum = 1; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags |= C_INITIALIZED; mx->mx_cursor.mc_ki[0] = 0; mx->mx_dbflag = DB_VALID | DB_USRVALID | DB_DUPDATA; mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp; } else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) { return; } mx->mx_db = src_mx->mx_db; mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0]; mdbx_debug("Sub-db -%u root page %zu", mx->mx_cursor.mc_dbi, mx->mx_db.md_root); } /** Initialize a cursor for a given transaction and database. */ static void mdbx_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx) { mc->mc_signature = MDBX_MC_SIGNATURE; mc->mc_next = NULL; mc->mc_backup = NULL; mc->mc_dbi = dbi; mc->mc_txn = txn; mc->mc_db = &txn->mt_dbs[dbi]; mc->mc_dbx = &txn->mt_dbxs[dbi]; mc->mc_dbflag = &txn->mt_dbflags[dbi]; mc->mc_snum = 0; mc->mc_top = 0; mc->mc_pg[0] = 0; mc->mc_flags = 0; mc->mc_ki[0] = 0; mc->mc_xcursor = NULL; if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { mdbx_tassert(txn, mx != NULL); mx->mx_cursor.mc_signature = MDBX_MC_SIGNATURE; mc->mc_xcursor = mx; mdbx_xcursor_init0(mc); } if (unlikely(*mc->mc_dbflag & DB_STALE)) { mdbx_page_search(mc, NULL, MDB_PS_ROOTONLY); } } int mdbx_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret) { MDB_cursor *mc; size_t size = sizeof(MDB_cursor); if (unlikely(!ret || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_VALID))) return EINVAL; if (unlikely(txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; if (unlikely(dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))) return EINVAL; if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) size += sizeof(MDB_xcursor); if (likely((mc = malloc(size)) != NULL)) { mdbx_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1)); if (txn->mt_cursors) { mc->mc_next = txn->mt_cursors[dbi]; txn->mt_cursors[dbi] = mc; mc->mc_flags |= C_UNTRACK; } } else { return ENOMEM; } *ret = mc; return MDB_SUCCESS; } int mdbx_cursor_renew(MDB_txn *txn, MDB_cursor *mc) { if (unlikely(!mc || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE && mc->mc_signature != MDBX_MC_READY4CLOSE)) return EINVAL; if (unlikely(!TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))) return EINVAL; if (unlikely(mc->mc_backup)) return EINVAL; if (unlikely((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)) { #if MDBX_MODE_ENABLED MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi]; while (*prev && *prev != mc) prev = &(*prev)->mc_next; if (*prev == mc) *prev = mc->mc_next; mc->mc_signature = MDBX_MC_READY4CLOSE; #else return EINVAL; #endif } if (unlikely(txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; mdbx_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor); return MDB_SUCCESS; } /* Return the count of duplicate data items for the current key */ int mdbx_cursor_count(MDB_cursor *mc, size_t *countp) { if (unlikely(mc == NULL || countp == NULL)) return EINVAL; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; if (unlikely(!(mc->mc_flags & C_INITIALIZED))) return EINVAL; #if MDBX_MODE_ENABLED if (!mc->mc_snum) { *countp = 0; return MDB_NOTFOUND; } MDB_page *mp = mc->mc_pg[mc->mc_top]; if ((mc->mc_flags & C_EOF) && mc->mc_ki[mc->mc_top] >= NUMKEYS(mp)) { *countp = 0; return MDB_NOTFOUND; } *countp = 1; if (mc->mc_xcursor != NULL) { MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_cassert(mc, mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)); *countp = mc->mc_xcursor->mx_db.md_entries; } } #else if (unlikely(mc->mc_xcursor == NULL)) return MDB_INCOMPATIBLE; if (!mc->mc_snum) return MDB_NOTFOUND; MDB_page *mp = mc->mc_pg[mc->mc_top]; if ((mc->mc_flags & C_EOF) && mc->mc_ki[mc->mc_top] >= NUMKEYS(mp)) return MDB_NOTFOUND; MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { *countp = 1; } else { if (unlikely(!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))) return EINVAL; *countp = mc->mc_xcursor->mx_db.md_entries; } #endif /* MDBX_MODE_ENABLED */ return MDB_SUCCESS; } void mdbx_cursor_close(MDB_cursor *mc) { if (mc) { mdbx_ensure(NULL, mc->mc_signature == MDBX_MC_SIGNATURE || mc->mc_signature == MDBX_MC_READY4CLOSE); if (!mc->mc_backup) { /* Remove from txn, if tracked. * A read-only txn (!C_UNTRACK) may have been freed already, * so do not peek inside it. Only write txns track cursors. */ if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) { MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi]; while (*prev && *prev != mc) prev = &(*prev)->mc_next; if (*prev == mc) *prev = mc->mc_next; } mc->mc_signature = 0; free(mc); } else { /* cursor closed before nested txn ends */ mdbx_cassert(mc, mc->mc_signature == MDBX_MC_SIGNATURE); mc->mc_signature = MDBX_MC_WAIT4EOT; } } } MDB_txn *mdbx_cursor_txn(MDB_cursor *mc) { if (unlikely(!mc || mc->mc_signature != MDBX_MC_SIGNATURE)) return NULL; return mc->mc_txn; } MDB_dbi mdbx_cursor_dbi(MDB_cursor *mc) { if (unlikely(!mc || mc->mc_signature != MDBX_MC_SIGNATURE)) return INT_MIN; return mc->mc_dbi; } /** Replace the key for a branch node with a new key. * Set #MDB_TXN_ERROR on failure. * @param[in] mc Cursor pointing to the node to operate on. * @param[in] key The new key to use. * @return 0 on success, non-zero on failure. */ static int mdbx_update_key(MDB_cursor *mc, MDB_val *key) { MDB_page *mp; MDB_node *node; char *base; size_t len; int delta, ksize, oksize; indx_t ptr, i, numkeys, indx; DKBUF; indx = mc->mc_ki[mc->mc_top]; mp = mc->mc_pg[mc->mc_top]; node = NODEPTR(mp, indx); ptr = mp->mp_ptrs[indx]; { MDB_val k2; char kbuf2[DKBUF_MAXKEYSIZE * 2 + 1]; k2.mv_data = NODEKEY(node); k2.mv_size = node->mn_ksize; mdbx_debug("update key %u (ofs %u) [%s] to [%s] on page %zu", indx, ptr, mdbx_dkey(&k2, kbuf2), DKEY(key), mp->mp_pgno); } /* Sizes must be 2-byte aligned. */ ksize = EVEN(key->mv_size); oksize = EVEN(node->mn_ksize); delta = ksize - oksize; /* Shift node contents if EVEN(key length) changed. */ if (delta) { if (delta > 0 && SIZELEFT(mp) < delta) { pgno_t pgno; /* not enough space left, do a delete and split */ mdbx_debug("Not enough room, delta = %d, splitting...", delta); pgno = NODEPGNO(node); mdbx_node_del(mc, 0); return mdbx_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE); } numkeys = NUMKEYS(mp); for (i = 0; i < numkeys; i++) { if (mp->mp_ptrs[i] <= ptr) mp->mp_ptrs[i] -= delta; } base = (char *)mp + mp->mp_upper + PAGEBASE; len = ptr - mp->mp_upper + NODESIZE; memmove(base - delta, base, len); mp->mp_upper -= delta; node = NODEPTR(mp, indx); } /* But even if no shift was needed, update ksize */ if (node->mn_ksize != key->mv_size) node->mn_ksize = key->mv_size; if (key->mv_size) memcpy(NODEKEY(node), key->mv_data, key->mv_size); return MDB_SUCCESS; } static void mdbx_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst); /** Perform \b act while tracking temporary cursor \b mn */ #define WITH_CURSOR_TRACKING(mn, act) \ do { \ MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \ if ((mn).mc_flags & C_SUB) { \ dummy.mc_flags = C_INITIALIZED; \ dummy.mc_xcursor = (MDB_xcursor *)&(mn); \ tracked = &dummy; \ } else { \ tracked = &(mn); \ } \ tracked->mc_next = *tp; \ *tp = tracked; \ { act; } \ *tp = tracked->mc_next; \ } while (0) /** Move a node from csrc to cdst. */ static int mdbx_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft) { MDB_node *srcnode; MDB_val key, data; pgno_t srcpg; MDB_cursor mn; int rc; unsigned short flags; DKBUF; /* Mark src and dst as dirty. */ if (unlikely((rc = mdbx_page_touch(csrc)) || (rc = mdbx_page_touch(cdst)))) return rc; if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_size = csrc->mc_db->md_xsize; key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size); data.mv_size = 0; data.mv_data = NULL; srcpg = 0; flags = 0; } else { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]); mdbx_cassert(csrc, !((size_t)srcnode & 1)); srcpg = NODEPGNO(srcnode); flags = srcnode->mn_flags; if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { unsigned snum = csrc->mc_snum; MDB_node *s2; /* must find the lowest key below src */ rc = mdbx_page_search_lowest(csrc); if (unlikely(rc)) return rc; if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_size = csrc->mc_db->md_xsize; key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); } else { s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); key.mv_size = NODEKSZ(s2); key.mv_data = NODEKEY(s2); } csrc->mc_snum = snum--; csrc->mc_top = snum; } else { key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } data.mv_size = NODEDSZ(srcnode); data.mv_data = NODEDATA(srcnode); } mn.mc_xcursor = NULL; if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) { unsigned snum = cdst->mc_snum; MDB_node *s2; MDB_val bkey; /* must find the lowest key below dst */ mdbx_cursor_copy(cdst, &mn); rc = mdbx_page_search_lowest(&mn); if (unlikely(rc)) return rc; if (IS_LEAF2(mn.mc_pg[mn.mc_top])) { bkey.mv_size = mn.mc_db->md_xsize; bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size); } else { s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0); bkey.mv_size = NODEKSZ(s2); bkey.mv_data = NODEKEY(s2); } mn.mc_snum = snum--; mn.mc_top = snum; mn.mc_ki[snum] = 0; rc = mdbx_update_key(&mn, &bkey); if (unlikely(rc)) return rc; } mdbx_debug("moving %s node %u [%s] on page %zu to node %u on page %zu", IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch", csrc->mc_ki[csrc->mc_top], DKEY(&key), csrc->mc_pg[csrc->mc_top]->mp_pgno, cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno); /* Add the node to the destination page. */ rc = mdbx_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags); if (unlikely(rc != MDB_SUCCESS)) return rc; /* Delete the node from the source page. */ mdbx_node_del(csrc, key.mv_size); { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = csrc->mc_dbi; MDB_page *mpd, *mps; mps = csrc->mc_pg[csrc->mc_top]; /* If we're adding on the left, bump others up */ if (fromleft) { mpd = cdst->mc_pg[csrc->mc_top]; for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { if (csrc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top) continue; if (m3 != cdst && m3->mc_pg[csrc->mc_top] == mpd && m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) { m3->mc_ki[csrc->mc_top]++; } if (m3 != csrc && m3->mc_pg[csrc->mc_top] == mps && m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) { m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top]; m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top]; m3->mc_ki[csrc->mc_top - 1]++; } if (XCURSOR_INITED(m3) && IS_LEAF(mps)) XCURSOR_REFRESH(m3, m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]); } } else /* Adding on the right, bump others down */ { for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { if (csrc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == csrc) continue; if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top) continue; if (m3->mc_pg[csrc->mc_top] == mps) { if (!m3->mc_ki[csrc->mc_top]) { m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top]; m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top]; m3->mc_ki[csrc->mc_top - 1]--; } else { m3->mc_ki[csrc->mc_top]--; } if (XCURSOR_INITED(m3) && IS_LEAF(mps)) XCURSOR_REFRESH(m3, m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]); } } } } /* Update the parent separators. */ if (csrc->mc_ki[csrc->mc_top] == 0) { if (csrc->mc_ki[csrc->mc_top - 1] != 0) { if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); } else { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } mdbx_debug("update separator for source page %zu to [%s]", csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)); mdbx_cursor_copy(csrc, &mn); mn.mc_snum--; mn.mc_top--; /* We want mdbx_rebalance to find mn when doing fixups */ WITH_CURSOR_TRACKING(mn, rc = mdbx_update_key(&mn, &key)); if (unlikely(rc != MDB_SUCCESS)) return rc; } if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { MDB_val nullkey; indx_t ix = csrc->mc_ki[csrc->mc_top]; nullkey.mv_size = 0; csrc->mc_ki[csrc->mc_top] = 0; rc = mdbx_update_key(csrc, &nullkey); csrc->mc_ki[csrc->mc_top] = ix; mdbx_cassert(csrc, rc == MDB_SUCCESS); } } if (cdst->mc_ki[cdst->mc_top] == 0) { if (cdst->mc_ki[cdst->mc_top - 1] != 0) { if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size); } else { srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0); key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } mdbx_debug("update separator for destination page %zu to [%s]", cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)); mdbx_cursor_copy(cdst, &mn); mn.mc_snum--; mn.mc_top--; /* We want mdbx_rebalance to find mn when doing fixups */ WITH_CURSOR_TRACKING(mn, rc = mdbx_update_key(&mn, &key)); if (unlikely(rc != MDB_SUCCESS)) return rc; } if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) { MDB_val nullkey; indx_t ix = cdst->mc_ki[cdst->mc_top]; nullkey.mv_size = 0; cdst->mc_ki[cdst->mc_top] = 0; rc = mdbx_update_key(cdst, &nullkey); cdst->mc_ki[cdst->mc_top] = ix; mdbx_cassert(cdst, rc == MDB_SUCCESS); } } return MDB_SUCCESS; } /** Merge one page into another. * The nodes from the page pointed to by \b csrc will * be copied to the page pointed to by \b cdst and then * the \b csrc page will be freed. * @param[in] csrc Cursor pointing to the source page. * @param[in] cdst Cursor pointing to the destination page. * @return 0 on success, non-zero on failure. */ static int mdbx_page_merge(MDB_cursor *csrc, MDB_cursor *cdst) { MDB_page *psrc, *pdst; MDB_node *srcnode; MDB_val key, data; unsigned nkeys; int rc; indx_t i, j; psrc = csrc->mc_pg[csrc->mc_top]; pdst = cdst->mc_pg[cdst->mc_top]; mdbx_debug("merging page %zu into %zu", psrc->mp_pgno, pdst->mp_pgno); mdbx_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */ mdbx_cassert(csrc, cdst->mc_snum > 1); /* Mark dst as dirty. */ if (unlikely(rc = mdbx_page_touch(cdst))) return rc; /* get dst page again now that we've touched it. */ pdst = cdst->mc_pg[cdst->mc_top]; /* Move all nodes from src to dst. */ j = nkeys = NUMKEYS(pdst); if (IS_LEAF2(psrc)) { key.mv_size = csrc->mc_db->md_xsize; key.mv_data = PAGEDATA(psrc); for (i = 0; i < NUMKEYS(psrc); i++, j++) { rc = mdbx_node_add(cdst, j, &key, NULL, 0, 0); if (unlikely(rc != MDB_SUCCESS)) return rc; key.mv_data = (char *)key.mv_data + key.mv_size; } } else { for (i = 0; i < NUMKEYS(psrc); i++, j++) { srcnode = NODEPTR(psrc, i); if (i == 0 && IS_BRANCH(psrc)) { MDB_cursor mn; MDB_node *s2; mdbx_cursor_copy(csrc, &mn); mn.mc_xcursor = NULL; /* must find the lowest key below src */ rc = mdbx_page_search_lowest(&mn); if (unlikely(rc)) return rc; if (IS_LEAF2(mn.mc_pg[mn.mc_top])) { key.mv_size = mn.mc_db->md_xsize; key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size); } else { s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0); key.mv_size = NODEKSZ(s2); key.mv_data = NODEKEY(s2); } } else { key.mv_size = srcnode->mn_ksize; key.mv_data = NODEKEY(srcnode); } data.mv_size = NODEDSZ(srcnode); data.mv_data = NODEDATA(srcnode); rc = mdbx_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags); if (unlikely(rc != MDB_SUCCESS)) return rc; } } mdbx_debug("dst page %zu now has %u keys (%.1f%% filled)", pdst->mp_pgno, NUMKEYS(pdst), (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10); /* Unlink the src page from parent and add to free list. */ csrc->mc_top--; mdbx_node_del(csrc, 0); if (csrc->mc_ki[csrc->mc_top] == 0) { key.mv_size = 0; rc = mdbx_update_key(csrc, &key); if (unlikely(rc)) { csrc->mc_top++; return rc; } } csrc->mc_top++; psrc = csrc->mc_pg[csrc->mc_top]; /* If not operating on FreeDB, allow this page to be reused * in this txn. Otherwise just add to free list. */ rc = mdbx_page_loose(csrc, psrc); if (unlikely(rc)) return rc; if (IS_LEAF(psrc)) csrc->mc_db->md_leaf_pages--; else csrc->mc_db->md_branch_pages--; { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = csrc->mc_dbi; unsigned top = csrc->mc_top; for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { if (csrc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == csrc) continue; if (m3->mc_snum < csrc->mc_snum) continue; if (m3->mc_pg[top] == psrc) { m3->mc_pg[top] = pdst; m3->mc_ki[top] += nkeys; m3->mc_ki[top - 1] = cdst->mc_ki[top - 1]; } else if (m3->mc_pg[top - 1] == csrc->mc_pg[top - 1] && m3->mc_ki[top - 1] > csrc->mc_ki[top - 1]) { m3->mc_ki[top - 1]--; } if (XCURSOR_INITED(m3) && IS_LEAF(psrc)) XCURSOR_REFRESH(m3, m3->mc_pg[top], m3->mc_ki[top]); } } { unsigned snum = cdst->mc_snum; uint16_t depth = cdst->mc_db->md_depth; mdbx_cursor_pop(cdst); rc = mdbx_rebalance(cdst); /* Did the tree height change? */ if (depth != cdst->mc_db->md_depth) snum += cdst->mc_db->md_depth - depth; cdst->mc_snum = snum; cdst->mc_top = snum - 1; } return rc; } /** Copy the contents of a cursor. * @param[in] csrc The cursor to copy from. * @param[out] cdst The cursor to copy to. */ static void mdbx_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst) { unsigned i; cdst->mc_txn = csrc->mc_txn; cdst->mc_dbi = csrc->mc_dbi; cdst->mc_db = csrc->mc_db; cdst->mc_dbx = csrc->mc_dbx; cdst->mc_snum = csrc->mc_snum; cdst->mc_top = csrc->mc_top; cdst->mc_flags = csrc->mc_flags; for (i = 0; i < csrc->mc_snum; i++) { cdst->mc_pg[i] = csrc->mc_pg[i]; cdst->mc_ki[i] = csrc->mc_ki[i]; } } /** Rebalance the tree after a delete operation. * @param[in] mc Cursor pointing to the page where rebalancing * should begin. * @return 0 on success, non-zero on failure. */ static int mdbx_rebalance(MDB_cursor *mc) { MDB_node *node; int rc, fromleft; unsigned ptop, minkeys, thresh; MDB_cursor mn; indx_t oldki; if (IS_BRANCH(mc->mc_pg[mc->mc_top])) { minkeys = 2; thresh = 1; } else { minkeys = 1; thresh = FILL_THRESHOLD; } mdbx_debug("rebalancing %s page %zu (has %u keys, %.1f%% full)", IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch", mdbx_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10); if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh && NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) { mdbx_debug("no need to rebalance page %zu, above fill threshold", mdbx_dbg_pgno(mc->mc_pg[mc->mc_top])); return MDB_SUCCESS; } if (mc->mc_snum < 2) { MDB_page *mp = mc->mc_pg[0]; unsigned nkeys = NUMKEYS(mp); if (IS_SUBP(mp)) { mdbx_debug("Can't rebalance a subpage, ignoring"); return MDB_SUCCESS; } if (nkeys == 0) { mdbx_debug("tree is completely empty"); mc->mc_db->md_root = P_INVALID; mc->mc_db->md_depth = 0; mc->mc_db->md_leaf_pages = 0; rc = mdbx_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); if (unlikely(rc)) return rc; /* Adjust cursors pointing to mp */ mc->mc_snum = 0; mc->mc_top = 0; mc->mc_flags &= ~C_INITIALIZED; { MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum)) continue; if (m3->mc_pg[0] == mp) { m3->mc_snum = 0; m3->mc_top = 0; m3->mc_flags &= ~C_INITIALIZED; } } } } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) { int i; mdbx_debug("collapsing root page!"); rc = mdbx_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); if (unlikely(rc)) return rc; mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0)); rc = mdbx_page_get(mc, mc->mc_db->md_root, &mc->mc_pg[0], NULL); if (unlikely(rc)) return rc; mc->mc_db->md_depth--; mc->mc_db->md_branch_pages--; mc->mc_ki[0] = mc->mc_ki[1]; for (i = 1; i < mc->mc_db->md_depth; i++) { mc->mc_pg[i] = mc->mc_pg[i + 1]; mc->mc_ki[i] = mc->mc_ki[i + 1]; } { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == mc) continue; if (!(m3->mc_flags & C_INITIALIZED)) continue; if (m3->mc_pg[0] == mp) { for (i = 0; i < mc->mc_db->md_depth; i++) { m3->mc_pg[i] = m3->mc_pg[i + 1]; m3->mc_ki[i] = m3->mc_ki[i + 1]; } m3->mc_snum--; m3->mc_top--; } } } } else mdbx_debug("root page doesn't need rebalancing"); return MDB_SUCCESS; } /* The parent (branch page) must have at least 2 pointers, * otherwise the tree is invalid. */ ptop = mc->mc_top - 1; mdbx_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1); /* Leaf page fill factor is below the threshold. * Try to move keys from left or right neighbor, or * merge with a neighbor page. */ /* Find neighbors. */ mdbx_cursor_copy(mc, &mn); mn.mc_xcursor = NULL; oldki = mc->mc_ki[mc->mc_top]; if (mc->mc_ki[ptop] == 0) { /* We're the leftmost leaf in our parent. */ mdbx_debug("reading right neighbor"); mn.mc_ki[ptop]++; node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); rc = mdbx_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL); if (unlikely(rc)) return rc; mn.mc_ki[mn.mc_top] = 0; mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]); fromleft = 0; } else { /* There is at least one neighbor to the left. */ mdbx_debug("reading left neighbor"); mn.mc_ki[ptop]--; node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); rc = mdbx_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL); if (unlikely(rc)) return rc; mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1; mc->mc_ki[mc->mc_top] = 0; fromleft = 1; } mdbx_debug("found neighbor page %zu (%u keys, %.1f%% full)", mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10); /* If the neighbor page is above threshold and has enough keys, * move one key from it. Otherwise we should try to merge them. * (A branch page must never have less than 2 keys.) */ if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) { rc = mdbx_node_move(&mn, mc, fromleft); if (fromleft) { /* if we inserted on left, bump position up */ oldki++; } } else { if (!fromleft) { rc = mdbx_page_merge(&mn, mc); } else { oldki += NUMKEYS(mn.mc_pg[mn.mc_top]); mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1; /* We want mdbx_rebalance to find mn when doing fixups */ WITH_CURSOR_TRACKING(mn, rc = mdbx_page_merge(mc, &mn)); mdbx_cursor_copy(&mn, mc); } mc->mc_flags &= ~C_EOF; } mc->mc_ki[mc->mc_top] = oldki; return rc; } /** Complete a delete operation started by #mdbx_cursor_del(). */ static int mdbx_cursor_del0(MDB_cursor *mc) { int rc; MDB_page *mp; indx_t ki; unsigned nkeys; MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; ki = mc->mc_ki[mc->mc_top]; mp = mc->mc_pg[mc->mc_top]; mdbx_node_del(mc, mc->mc_db->md_xsize); mc->mc_db->md_entries--; { /* Adjust other cursors pointing to mp */ for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2; if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED)) continue; if (m3 == mc || m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[mc->mc_top] == mp) { if (m3->mc_ki[mc->mc_top] == ki) { m3->mc_flags |= C_DEL; if (mc->mc_db->md_flags & MDB_DUPSORT) { /* Sub-cursor referred into dataset which is gone */ m3->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF); } continue; } else if (m3->mc_ki[mc->mc_top] > ki) { m3->mc_ki[mc->mc_top]--; } if (XCURSOR_INITED(m3)) XCURSOR_REFRESH(m3, m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]); } } } rc = mdbx_rebalance(mc); if (likely(rc == MDB_SUCCESS)) { /* DB is totally empty now, just bail out. * Other cursors adjustments were already done * by mdbx_rebalance and aren't needed here. */ if (!mc->mc_snum) { mc->mc_flags |= C_DEL | C_EOF; return rc; } mp = mc->mc_pg[mc->mc_top]; nkeys = NUMKEYS(mp); /* Adjust other cursors pointing to mp */ for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2 = m2->mc_next) { m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2; if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED)) continue; if (m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[mc->mc_top] == mp) { /* if m3 points past last node in page, find next sibling */ if (m3->mc_ki[mc->mc_top] >= mc->mc_ki[mc->mc_top]) { if (m3->mc_ki[mc->mc_top] >= nkeys) { rc = mdbx_cursor_sibling(m3, 1); if (rc == MDB_NOTFOUND) { m3->mc_flags |= C_EOF; rc = MDB_SUCCESS; continue; } } if (mc->mc_db->md_flags & MDB_DUPSORT) { MDB_node *node = NODEPTR(m3->mc_pg[m3->mc_top], m3->mc_ki[m3->mc_top]); /* If this node is a fake page, it needs to be reinited * because its data has moved. But just reset mc_pg[0] * if the xcursor is already live. */ if ((node->mn_flags & (F_DUPDATA | F_SUBDATA)) == F_DUPDATA) { if (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node); else mdbx_xcursor_init1(m3, node); } } } } } mc->mc_flags |= C_DEL; } if (unlikely(rc)) mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdbx_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) { if (unlikely(!key || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; if (unlikely(txn->mt_flags & (MDB_TXN_RDONLY | MDB_TXN_BLOCKED))) return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; #if !MDBX_MODE_ENABLED if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) { /* must ignore any data */ data = NULL; } #endif return mdbx_del0(txn, dbi, key, data, 0); } static int mdbx_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags) { MDB_cursor mc; MDB_xcursor mx; MDB_cursor_op op; MDB_val rdata; int rc, exact = 0; DKBUF; mdbx_debug("====> delete db %u key [%s]", dbi, DKEY(key)); mdbx_cursor_init(&mc, txn, dbi, &mx); if (data) { op = MDB_GET_BOTH; rdata = *data; data = &rdata; } else { op = MDB_SET; flags |= MDB_NODUPDATA; } rc = mdbx_cursor_set(&mc, key, data, op, &exact); if (likely(rc == 0)) { /* let mdbx_page_split know about this cursor if needed: * delete will trigger a rebalance; if it needs to move * a node from one page to another, it will have to * update the parent's separator key(s). If the new sepkey * is larger than the current one, the parent page may * run out of space, triggering a split. We need this * cursor to be consistent until the end of the rebalance. */ mc.mc_next = txn->mt_cursors[dbi]; txn->mt_cursors[dbi] = &mc; rc = mdbx_cursor_del(&mc, flags); txn->mt_cursors[dbi] = mc.mc_next; } return rc; } /** Split a page and insert a new node. * Set #MDB_TXN_ERROR on failure. * @param[in,out] mc Cursor pointing to the page and desired insertion index. * The cursor will be updated to point to the actual page and index where * the node got inserted after the split. * @param[in] newkey The key for the newly inserted node. * @param[in] newdata The data for the newly inserted node. * @param[in] newpgno The page number, if the new node is a branch node. * @param[in] nflags The #NODE_ADD_FLAGS for the new node. * @return 0 on success, non-zero on failure. */ static int mdbx_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno, unsigned nflags) { unsigned flags; int rc = MDB_SUCCESS, new_root = 0, did_split = 0; indx_t newindx; pgno_t pgno = 0; int i, j, split_indx, nkeys, pmax; MDB_env *env = mc->mc_txn->mt_env; MDB_node *node; MDB_val sepkey, rkey, xdata, *rdata = &xdata; MDB_page *copy = NULL; MDB_page *mp, *rp, *pp; int ptop; MDB_cursor mn; DKBUF; mp = mc->mc_pg[mc->mc_top]; newindx = mc->mc_ki[mc->mc_top]; nkeys = NUMKEYS(mp); mdbx_debug("-----> splitting %s page %zu and adding [%s] at index %i/%i", IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno, DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys); /* Create a right sibling. */ if ((rc = mdbx_page_new(mc, mp->mp_flags, 1, &rp))) return rc; rp->mp_leaf2_ksize = mp->mp_leaf2_ksize; mdbx_debug("new right sibling: page %zu", rp->mp_pgno); /* Usually when splitting the root page, the cursor * height is 1. But when called from mdbx_update_key, * the cursor height may be greater because it walks * up the stack while finding the branch slot to update. */ if (mc->mc_top < 1) { if ((rc = mdbx_page_new(mc, P_BRANCH, 1, &pp))) goto done; /* shift current top to make room for new parent */ for (i = mc->mc_snum; i > 0; i--) { mc->mc_pg[i] = mc->mc_pg[i - 1]; mc->mc_ki[i] = mc->mc_ki[i - 1]; } mc->mc_pg[0] = pp; mc->mc_ki[0] = 0; mc->mc_db->md_root = pp->mp_pgno; mdbx_debug("root split! new root = %zu", pp->mp_pgno); new_root = mc->mc_db->md_depth++; /* Add left (implicit) pointer. */ if (unlikely((rc = mdbx_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS)) { /* undo the pre-push */ mc->mc_pg[0] = mc->mc_pg[1]; mc->mc_ki[0] = mc->mc_ki[1]; mc->mc_db->md_root = mp->mp_pgno; mc->mc_db->md_depth--; goto done; } mc->mc_snum++; mc->mc_top++; ptop = 0; } else { ptop = mc->mc_top - 1; mdbx_debug("parent branch page is %zu", mc->mc_pg[ptop]->mp_pgno); } mdbx_cursor_copy(mc, &mn); mn.mc_xcursor = NULL; mn.mc_pg[mn.mc_top] = rp; mn.mc_ki[ptop] = mc->mc_ki[ptop] + 1; if (nflags & MDB_APPEND) { mn.mc_ki[mn.mc_top] = 0; sepkey = *newkey; split_indx = newindx; nkeys = 0; } else { split_indx = (nkeys + 1) / 2; if (IS_LEAF2(rp)) { char *split, *ins; int x; unsigned lsize, rsize, ksize; /* Move half of the keys to the right sibling */ x = mc->mc_ki[mc->mc_top] - split_indx; ksize = mc->mc_db->md_xsize; split = LEAF2KEY(mp, split_indx, ksize); rsize = (nkeys - split_indx) * ksize; lsize = (nkeys - split_indx) * sizeof(indx_t); mp->mp_lower -= lsize; rp->mp_lower += lsize; mp->mp_upper += rsize - lsize; rp->mp_upper -= rsize - lsize; sepkey.mv_size = ksize; if (newindx == split_indx) { sepkey.mv_data = newkey->mv_data; } else { sepkey.mv_data = split; } if (x < 0) { ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize); memcpy(rp->mp_ptrs, split, rsize); sepkey.mv_data = rp->mp_ptrs; memmove(ins + ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize); memcpy(ins, newkey->mv_data, ksize); mp->mp_lower += sizeof(indx_t); mp->mp_upper -= ksize - sizeof(indx_t); } else { if (x) memcpy(rp->mp_ptrs, split, x * ksize); ins = LEAF2KEY(rp, x, ksize); memcpy(ins, newkey->mv_data, ksize); memcpy(ins + ksize, split + x * ksize, rsize - x * ksize); rp->mp_lower += sizeof(indx_t); rp->mp_upper -= ksize - sizeof(indx_t); mc->mc_ki[mc->mc_top] = x; } } else { int psize, nsize, k; /* Maximum free space in an empty page */ pmax = env->me_psize - PAGEHDRSZ; if (IS_LEAF(mp)) nsize = mdbx_leaf_size(env, newkey, newdata); else nsize = mdbx_branch_size(env, newkey); nsize = EVEN(nsize); /* grab a page to hold a temporary copy */ copy = mdbx_page_malloc(mc->mc_txn, 1); if (unlikely(copy == NULL)) { rc = ENOMEM; goto done; } copy->mp_pgno = mp->mp_pgno; copy->mp_flags = mp->mp_flags; copy->mp_lower = (PAGEHDRSZ - PAGEBASE); copy->mp_upper = env->me_psize - PAGEBASE; /* prepare to insert */ for (i = 0, j = 0; i < nkeys; i++) { if (i == newindx) { copy->mp_ptrs[j++] = 0; } copy->mp_ptrs[j++] = mp->mp_ptrs[i]; } /* When items are relatively large the split point needs * to be checked, because being off-by-one will make the * difference between success or failure in mdbx_node_add. * * It's also relevant if a page happens to be laid out * such that one half of its nodes are all "small" and * the other half of its nodes are "large." If the new * item is also "large" and falls on the half with * "large" nodes, it also may not fit. * * As a final tweak, if the new item goes on the last * spot on the page (and thus, onto the new page), bias * the split so the new page is emptier than the old page. * This yields better packing during sequential inserts. */ if (nkeys < 20 || nsize > pmax / 16 || newindx >= nkeys) { /* Find split point */ psize = 0; if (newindx <= split_indx || newindx >= nkeys) { i = 0; j = 1; k = newindx >= nkeys ? nkeys : split_indx + 1 + IS_LEAF(mp); } else { i = nkeys; j = -1; k = split_indx - 1; } for (; i != k; i += j) { if (i == newindx) { psize += nsize; node = NULL; } else { node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE); psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t); if (IS_LEAF(mp)) { if (F_ISSET(node->mn_flags, F_BIGDATA)) psize += sizeof(pgno_t); else psize += NODEDSZ(node); } psize = EVEN(psize); } if (psize > pmax || i == k - j) { split_indx = i + (j < 0); break; } } } if (split_indx == newindx) { sepkey.mv_size = newkey->mv_size; sepkey.mv_data = newkey->mv_data; } else { node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE); sepkey.mv_size = node->mn_ksize; sepkey.mv_data = NODEKEY(node); } } } mdbx_debug("separator is %d [%s]", split_indx, DKEY(&sepkey)); /* Copy separator key to the parent. */ if (SIZELEFT(mn.mc_pg[ptop]) < mdbx_branch_size(env, &sepkey)) { int snum = mc->mc_snum; mn.mc_snum--; mn.mc_top--; did_split = 1; /* We want other splits to find mn when doing fixups */ WITH_CURSOR_TRACKING( mn, rc = mdbx_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0)); if (unlikely(rc != MDB_SUCCESS)) goto done; /* root split? */ if (mc->mc_snum > snum) { ptop++; } /* Right page might now have changed parent. * Check if left page also changed parent. */ if (mn.mc_pg[ptop] != mc->mc_pg[ptop] && mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) { for (i = 0; i < ptop; i++) { mc->mc_pg[i] = mn.mc_pg[i]; mc->mc_ki[i] = mn.mc_ki[i]; } mc->mc_pg[ptop] = mn.mc_pg[ptop]; if (mn.mc_ki[ptop]) { mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1; } else { /* find right page's left sibling */ mc->mc_ki[ptop] = mn.mc_ki[ptop]; rc = mdbx_cursor_sibling(mc, 0); } } } else { mn.mc_top--; rc = mdbx_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0); mn.mc_top++; } if (unlikely(rc != MDB_SUCCESS)) { if (rc == MDB_NOTFOUND) /* improper mdbx_cursor_sibling() result */ rc = MDB_PROBLEM; goto done; } if (nflags & MDB_APPEND) { mc->mc_pg[mc->mc_top] = rp; mc->mc_ki[mc->mc_top] = 0; rc = mdbx_node_add(mc, 0, newkey, newdata, newpgno, nflags); if (rc) goto done; for (i = 0; i < mc->mc_top; i++) mc->mc_ki[i] = mn.mc_ki[i]; } else if (!IS_LEAF2(mp)) { /* Move nodes */ mc->mc_pg[mc->mc_top] = rp; i = split_indx; j = 0; do { if (i == newindx) { rkey.mv_data = newkey->mv_data; rkey.mv_size = newkey->mv_size; if (IS_LEAF(mp)) { rdata = newdata; } else pgno = newpgno; flags = nflags; /* Update index for the new key. */ mc->mc_ki[mc->mc_top] = j; } else { node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE); rkey.mv_data = NODEKEY(node); rkey.mv_size = node->mn_ksize; if (IS_LEAF(mp)) { xdata.mv_data = NODEDATA(node); xdata.mv_size = NODEDSZ(node); rdata = &xdata; } else pgno = NODEPGNO(node); flags = node->mn_flags; } if (!IS_LEAF(mp) && j == 0) { /* First branch index doesn't need key data. */ rkey.mv_size = 0; } rc = mdbx_node_add(mc, j, &rkey, rdata, pgno, flags); if (rc) goto done; if (i == nkeys) { i = 0; j = 0; mc->mc_pg[mc->mc_top] = copy; } else { i++; j++; } } while (i != split_indx); nkeys = NUMKEYS(copy); for (i = 0; i < nkeys; i++) mp->mp_ptrs[i] = copy->mp_ptrs[i]; mp->mp_lower = copy->mp_lower; mp->mp_upper = copy->mp_upper; memcpy(NODEPTR(mp, nkeys - 1), NODEPTR(copy, nkeys - 1), env->me_psize - copy->mp_upper - PAGEBASE); /* reset back to original page */ if (newindx < split_indx) { mc->mc_pg[mc->mc_top] = mp; } else { mc->mc_pg[mc->mc_top] = rp; mc->mc_ki[ptop]++; /* Make sure mc_ki is still valid. */ if (mn.mc_pg[ptop] != mc->mc_pg[ptop] && mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) { for (i = 0; i <= ptop; i++) { mc->mc_pg[i] = mn.mc_pg[i]; mc->mc_ki[i] = mn.mc_ki[i]; } } } if (nflags & MDB_RESERVE) { node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (!(node->mn_flags & F_BIGDATA)) newdata->mv_data = NODEDATA(node); } } else { if (newindx >= split_indx) { mc->mc_pg[mc->mc_top] = rp; mc->mc_ki[ptop]++; /* Make sure mc_ki is still valid. */ if (mn.mc_pg[ptop] != mc->mc_pg[ptop] && mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) { for (i = 0; i <= ptop; i++) { mc->mc_pg[i] = mn.mc_pg[i]; mc->mc_ki[i] = mn.mc_ki[i]; } } } } { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; nkeys = NUMKEYS(mp); for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == mc) continue; if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED)) continue; if (new_root) { int k; /* sub cursors may be on different DB */ if (m3->mc_pg[0] != mp) continue; /* root split */ for (k = new_root; k >= 0; k--) { m3->mc_ki[k + 1] = m3->mc_ki[k]; m3->mc_pg[k + 1] = m3->mc_pg[k]; } if (m3->mc_ki[0] >= nkeys) { m3->mc_ki[0] = 1; } else { m3->mc_ki[0] = 0; } m3->mc_pg[0] = mc->mc_pg[0]; m3->mc_snum++; m3->mc_top++; } if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) { if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE)) m3->mc_ki[mc->mc_top]++; if (m3->mc_ki[mc->mc_top] >= nkeys) { m3->mc_pg[mc->mc_top] = rp; m3->mc_ki[mc->mc_top] -= nkeys; for (i = 0; i < mc->mc_top; i++) { m3->mc_ki[i] = mn.mc_ki[i]; m3->mc_pg[i] = mn.mc_pg[i]; } } } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] && m3->mc_ki[ptop] >= mc->mc_ki[ptop]) { m3->mc_ki[ptop]++; } if (XCURSOR_INITED(m3) && IS_LEAF(mp)) XCURSOR_REFRESH(m3, m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]); } } mdbx_debug("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)); done: if (copy) /* tmp page */ mdbx_page_free(env, copy); if (unlikely(rc)) mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdbx_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags) { MDB_cursor mc; MDB_xcursor mx; if (unlikely(!key || !data || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; if (unlikely(flags & ~(MDB_NOOVERWRITE | MDB_NODUPDATA | MDB_RESERVE | MDB_APPEND | MDB_APPENDDUP /* LY: MDB_CURRENT indicates explicit overwrite (update) for MDBX */ | (MDBX_MODE_ENABLED ? MDB_CURRENT : 0)))) return EINVAL; if (unlikely(txn->mt_flags & (MDB_TXN_RDONLY | MDB_TXN_BLOCKED))) return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; mdbx_cursor_init(&mc, txn, dbi, &mx); mc.mc_next = txn->mt_cursors[dbi]; txn->mt_cursors[dbi] = &mc; int rc = MDB_SUCCESS; #if MDBX_MODE_ENABLED /* LY: support for update (explicit overwrite) */ if (flags & MDB_CURRENT) { rc = mdbx_cursor_get(&mc, key, NULL, MDB_SET); if (likely(rc == MDB_SUCCESS) && (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)) { /* LY: allows update (explicit overwrite) only for unique keys */ MDB_node *leaf = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_tassert(txn, XCURSOR_INITED(&mc) && mc.mc_xcursor->mx_db.md_entries > 1); rc = MDBX_EMULTIVAL; } } } #endif /* MDBX_MODE_ENABLED */ if (likely(rc == MDB_SUCCESS)) rc = mdbx_cursor_put(&mc, key, data, flags); txn->mt_cursors[dbi] = mc.mc_next; return rc; } #ifndef MDB_WBUF #define MDB_WBUF (1024 * 1024) #endif #define MDB_EOF 0x10 /**< #mdbx_env_copyfd1() is done reading */ /** State needed for a double-buffering compacting copy. */ typedef struct mdbx_copy { MDB_env *mc_env; MDB_txn *mc_txn; pthread_mutex_t mc_mutex; pthread_cond_t mc_cond; /**< Condition variable for #mc_new */ char *mc_wbuf[2]; char *mc_over[2]; int mc_wlen[2]; int mc_olen[2]; pgno_t mc_next_pgno; HANDLE mc_fd; int mc_toggle; /**< Buffer number in provider */ int mc_new; /**< (0-2 buffers to write) | (#MDB_EOF at end) */ /** Error code. Never cleared if set. Both threads can set nonzero * to fail the copy. Not mutex-protected, LMDB expects atomic int. */ volatile int mc_error; } mdbx_copy; /** Dedicated writer thread for compacting copy. */ static void *__cold mdbx_env_copythr(void *arg) { mdbx_copy *my = arg; char *ptr; int toggle = 0, wsize, rc = 0; int len; #ifdef SIGPIPE sigset_t set; sigemptyset(&set); sigaddset(&set, SIGPIPE); if ((rc = pthread_sigmask(SIG_BLOCK, &set, NULL)) != 0) my->mc_error = rc; #endif pthread_mutex_lock(&my->mc_mutex); for (;;) { while (!my->mc_new) pthread_cond_wait(&my->mc_cond, &my->mc_mutex); if (my->mc_new == 0 + MDB_EOF) /* 0 buffers, just EOF */ break; wsize = my->mc_wlen[toggle]; ptr = my->mc_wbuf[toggle]; again: rc = MDB_SUCCESS; while (wsize > 0 && !my->mc_error) { len = write(my->mc_fd, ptr, wsize); if (len < 0) { rc = errno; #ifdef SIGPIPE if (rc == EPIPE) { /* Collect the pending SIGPIPE, otherwise at least OS X * gives it to the process on thread-exit (ITS#8504). */ int tmp; sigwait(&set, &tmp); } #endif break; } else if (len > 0) { rc = MDB_SUCCESS; ptr += len; wsize -= len; continue; } else { rc = EIO; break; } } if (rc) { my->mc_error = rc; } /* If there's an overflow page tail, write it too */ if (my->mc_olen[toggle]) { wsize = my->mc_olen[toggle]; ptr = my->mc_over[toggle]; my->mc_olen[toggle] = 0; goto again; } my->mc_wlen[toggle] = 0; toggle ^= 1; /* Return the empty buffer to provider */ my->mc_new--; pthread_cond_signal(&my->mc_cond); } pthread_mutex_unlock(&my->mc_mutex); return NULL; } /** Give buffer and/or #MDB_EOF to writer thread, await unused buffer. * * @param[in] my control structure. * @param[in] adjust (1 to hand off 1 buffer) | (MDB_EOF when ending). */ static int __cold mdbx_env_cthr_toggle(mdbx_copy *my, int adjust) { pthread_mutex_lock(&my->mc_mutex); my->mc_new += adjust; pthread_cond_signal(&my->mc_cond); while (my->mc_new & 2) /* both buffers in use */ pthread_cond_wait(&my->mc_cond, &my->mc_mutex); pthread_mutex_unlock(&my->mc_mutex); my->mc_toggle ^= (adjust & 1); /* Both threads reset mc_wlen, to be safe from threading errors */ my->mc_wlen[my->mc_toggle] = 0; return my->mc_error; } /** Depth-first tree traversal for compacting copy. * @param[in] my control structure. * @param[in,out] pg database root. * @param[in] flags includes #F_DUPDATA if it is a sorted-duplicate sub-DB. */ static int __cold mdbx_env_cwalk(mdbx_copy *my, pgno_t *pg, int flags) { MDB_cursor mc; MDB_node *ni; MDB_page *mo, *mp, *leaf; char *buf, *ptr; int rc, toggle; unsigned i; /* Empty DB, nothing to do */ if (*pg == P_INVALID) return MDB_SUCCESS; memset(&mc, 0, sizeof(mc)); mc.mc_snum = 1; mc.mc_txn = my->mc_txn; rc = mdbx_page_get(&mc, *pg, &mc.mc_pg[0], NULL); if (rc) return rc; rc = mdbx_page_search_root(&mc, NULL, MDB_PS_FIRST); if (rc) return rc; /* Make cursor pages writable */ buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum); if (buf == NULL) return ENOMEM; for (i = 0; i < mc.mc_top; i++) { mdbx_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize); mc.mc_pg[i] = (MDB_page *)ptr; ptr += my->mc_env->me_psize; } /* This is writable space for a leaf page. Usually not needed. */ leaf = (MDB_page *)ptr; toggle = my->mc_toggle; while (mc.mc_snum > 0) { unsigned n; mp = mc.mc_pg[mc.mc_top]; n = NUMKEYS(mp); if (IS_LEAF(mp)) { if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) { for (i = 0; i < n; i++) { ni = NODEPTR(mp, i); if (ni->mn_flags & F_BIGDATA) { MDB_page *omp; pgno_t pg; /* Need writable leaf */ if (mp != leaf) { mc.mc_pg[mc.mc_top] = leaf; mdbx_page_copy(leaf, mp, my->mc_env->me_psize); mp = leaf; ni = NODEPTR(mp, i); } memcpy(&pg, NODEDATA(ni), sizeof(pg)); memcpy(NODEDATA(ni), &my->mc_next_pgno, sizeof(pgno_t)); rc = mdbx_page_get(&mc, pg, &omp, NULL); if (rc) goto done; if (my->mc_wlen[toggle] >= MDB_WBUF) { rc = mdbx_env_cthr_toggle(my, 1); if (rc) goto done; toggle = my->mc_toggle; } mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]); memcpy(mo, omp, my->mc_env->me_psize); mo->mp_pgno = my->mc_next_pgno; my->mc_next_pgno += omp->mp_pages; my->mc_wlen[toggle] += my->mc_env->me_psize; if (omp->mp_pages > 1) { my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1); my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize; rc = mdbx_env_cthr_toggle(my, 1); if (rc) goto done; toggle = my->mc_toggle; } } else if (ni->mn_flags & F_SUBDATA) { MDB_db db; /* Need writable leaf */ if (mp != leaf) { mc.mc_pg[mc.mc_top] = leaf; mdbx_page_copy(leaf, mp, my->mc_env->me_psize); mp = leaf; ni = NODEPTR(mp, i); } memcpy(&db, NODEDATA(ni), sizeof(db)); my->mc_toggle = toggle; rc = mdbx_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA); if (rc) goto done; toggle = my->mc_toggle; memcpy(NODEDATA(ni), &db, sizeof(db)); } } } } else { mc.mc_ki[mc.mc_top]++; if (mc.mc_ki[mc.mc_top] < n) { pgno_t pg; again: ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]); pg = NODEPGNO(ni); rc = mdbx_page_get(&mc, pg, &mp, NULL); if (rc) goto done; mc.mc_top++; mc.mc_snum++; mc.mc_ki[mc.mc_top] = 0; if (IS_BRANCH(mp)) { /* Whenever we advance to a sibling branch page, * we must proceed all the way down to its first leaf. */ mdbx_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize); goto again; } else mc.mc_pg[mc.mc_top] = mp; continue; } } if (my->mc_wlen[toggle] >= MDB_WBUF) { rc = mdbx_env_cthr_toggle(my, 1); if (rc) goto done; toggle = my->mc_toggle; } mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]); mdbx_page_copy(mo, mp, my->mc_env->me_psize); mo->mp_pgno = my->mc_next_pgno++; my->mc_wlen[toggle] += my->mc_env->me_psize; if (mc.mc_top) { /* Update parent if there is one */ ni = NODEPTR(mc.mc_pg[mc.mc_top - 1], mc.mc_ki[mc.mc_top - 1]); SETPGNO(ni, mo->mp_pgno); mdbx_cursor_pop(&mc); } else { /* Otherwise we're done */ *pg = mo->mp_pgno; break; } } done: free(buf); return rc; } /** Copy environment with compaction. */ static int __cold mdbx_env_copyfd1(MDB_env *env, HANDLE fd) { MDB_meta *mm; MDB_page *mp; mdbx_copy my; MDB_txn *txn = NULL; pthread_t thr; pgno_t root, new_root; int rc = MDB_SUCCESS; memset(&my, 0, sizeof(my)); if ((rc = pthread_mutex_init(&my.mc_mutex, NULL)) != 0) return rc; if ((rc = pthread_cond_init(&my.mc_cond, NULL)) != 0) goto done2; my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF * 2); if (my.mc_wbuf[0] == NULL) { rc = errno; goto done; } memset(my.mc_wbuf[0], 0, MDB_WBUF * 2); my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF; my.mc_next_pgno = NUM_METAS; my.mc_env = env; my.mc_fd = fd; rc = pthread_create(&thr, NULL, mdbx_env_copythr, &my); if (rc) goto done; rc = mdbx_txn_begin(env, NULL, MDB_RDONLY, &txn); if (rc) goto finish; mp = (MDB_page *)my.mc_wbuf[0]; memset(mp, 0, NUM_METAS * env->me_psize); mp->mp_pgno = 0; mp->mp_flags = P_META; mm = (MDB_meta *)PAGEDATA(mp); mdbx_env_init_meta0(env, mm); mm->mm_address = METAPAGE_1(env)->mm_address; mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize); mp->mp_pgno = 1; mp->mp_flags = P_META; *(MDB_meta *)PAGEDATA(mp) = *mm; mm = (MDB_meta *)PAGEDATA(mp); /* Set metapage 1 with current main DB */ root = new_root = txn->mt_dbs[MAIN_DBI].md_root; if (root != P_INVALID) { /* Count free pages + freeDB pages. Subtract from last_pg * to find the new last_pg, which also becomes the new root. */ MDB_ID freecount = 0; MDB_cursor mc; MDB_val key, data; mdbx_cursor_init(&mc, txn, FREE_DBI, NULL); while ((rc = mdbx_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0) freecount += *(MDB_ID *)data.mv_data; if (rc != MDB_NOTFOUND) goto finish; freecount += txn->mt_dbs[FREE_DBI].md_branch_pages + txn->mt_dbs[FREE_DBI].md_leaf_pages + txn->mt_dbs[FREE_DBI].md_overflow_pages; new_root = txn->mt_next_pgno - 1 - freecount; mm->mm_last_pg = new_root; mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI]; mm->mm_dbs[MAIN_DBI].md_root = new_root; } else { /* When the DB is empty, handle it specially to * fix any breakage like page leaks from ITS#8174. */ mm->mm_dbs[MAIN_DBI].md_flags = txn->mt_dbs[MAIN_DBI].md_flags; } if (root != P_INVALID || mm->mm_dbs[MAIN_DBI].md_flags) { mm->mm_txnid = 1; /* use metapage 1 */ } my.mc_wlen[0] = env->me_psize * NUM_METAS; my.mc_txn = txn; rc = mdbx_env_cwalk(&my, &root, 0); if (rc == MDB_SUCCESS && root != new_root) { rc = MDB_INCOMPATIBLE; /* page leak or corrupt DB */ } finish: if (rc) my.mc_error = rc; mdbx_env_cthr_toggle(&my, 1 | MDB_EOF); rc = pthread_join(thr, NULL); mdbx_txn_abort(txn); done: free(my.mc_wbuf[0]); pthread_cond_destroy(&my.mc_cond); done2: pthread_mutex_destroy(&my.mc_mutex); return rc ? rc : my.mc_error; } /** Copy environment as-is. */ static int __cold mdbx_env_copyfd0(MDB_env *env, HANDLE fd) { MDB_txn *txn = NULL; pthread_mutex_t *wmutex = NULL; int rc; size_t wsize; char *ptr; ssize_t len; size_t w2; /* Do the lock/unlock of the reader mutex before starting the * write txn. Otherwise other read txns could block writers. */ rc = mdbx_txn_begin(env, NULL, MDB_RDONLY, &txn); if (rc) return rc; /* We must start the actual read txn after blocking writers */ rc = mdbx_txn_end(txn, MDB_END_RESET_TMP); if (rc) return rc; /* Temporarily block writers until we snapshot the meta pages */ wmutex = MDB_MUTEX(env, w); rc = mdbx_mutex_lock(env, wmutex); if (unlikely(rc)) goto leave; rc = mdbx_txn_renew0(txn, MDB_RDONLY); if (rc) { mdbx_mutex_unlock(env, wmutex); goto leave; } wsize = env->me_psize * NUM_METAS; ptr = env->me_map; w2 = wsize; while (w2 > 0) { len = write(fd, ptr, w2); if (len < 0) { rc = errno; break; } else if (len > 0) { rc = MDB_SUCCESS; ptr += len; w2 -= len; continue; } else { /* Non-blocking or async handles are not supported */ rc = EIO; break; } } mdbx_mutex_unlock(env, wmutex); if (rc) goto leave; w2 = txn->mt_next_pgno * env->me_psize; { size_t fsize = 0; if ((rc = mdbx_fsize(env->me_fd, &fsize))) goto leave; if (w2 > fsize) w2 = fsize; } wsize = w2 - wsize; while (wsize > 0) { if (wsize > MAX_WRITE) w2 = MAX_WRITE; else w2 = wsize; len = write(fd, ptr, w2); if (len < 0) { rc = errno; break; } else if (len > 0) { rc = MDB_SUCCESS; ptr += len; wsize -= len; continue; } else { rc = EIO; break; } } leave: mdbx_txn_abort(txn); return rc; } int __cold mdbx_env_copyfd2(MDB_env *env, HANDLE fd, unsigned flags) { if (flags & MDB_CP_COMPACT) return mdbx_env_copyfd1(env, fd); else return mdbx_env_copyfd0(env, fd); } int __cold mdbx_env_copyfd(MDB_env *env, HANDLE fd) { return mdbx_env_copyfd2(env, fd, 0); } int __cold mdbx_env_copy2(MDB_env *env, const char *path, unsigned flags) { int rc, len; char *lpath; HANDLE newfd = INVALID_HANDLE_VALUE; if (env->me_flags & MDB_NOSUBDIR) { lpath = (char *)path; } else { len = strlen(path); len += sizeof(DATANAME); lpath = malloc(len); if (!lpath) return ENOMEM; sprintf(lpath, "%s" DATANAME, path); } /* The destination path must exist, but the destination file must not. * We don't want the OS to cache the writes, since the source data is * already in the OS cache. */ newfd = open(lpath, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC, 0666); if (newfd == INVALID_HANDLE_VALUE) { rc = errno; goto leave; } int fdflags; if ((fdflags = fcntl(newfd, F_GETFD) | FD_CLOEXEC) >= 0) fcntl(newfd, F_SETFD, fdflags); if (env->me_psize >= env->me_os_psize) { #ifdef F_NOCACHE /* __APPLE__ */ (void)fcntl(newfd, F_NOCACHE, 1); #elif defined O_DIRECT /* Set O_DIRECT if the file system supports it */ if ((rc = fcntl(newfd, F_GETFL)) != -1) (void)fcntl(newfd, F_SETFL, rc | O_DIRECT); #endif } rc = mdbx_env_copyfd2(env, newfd, flags); leave: if (!(env->me_flags & MDB_NOSUBDIR)) free(lpath); if (newfd != INVALID_HANDLE_VALUE) if (close(newfd) < 0 && rc == MDB_SUCCESS) rc = errno; return rc; } int __cold mdbx_env_copy(MDB_env *env, const char *path) { return mdbx_env_copy2(env, path, 0); } int __cold mdbx_env_set_flags(MDB_env *env, unsigned flags, int onoff) { if (unlikely(flags & ~CHANGEABLE)) return EINVAL; pthread_mutex_t *mutex = MDB_MUTEX(env, w); int rc = mdbx_mutex_lock(env, mutex); if (unlikely(rc)) return rc; if (onoff) env->me_flags |= flags; else env->me_flags &= ~flags; mdbx_mutex_unlock(env, mutex); return MDB_SUCCESS; } int __cold mdbx_env_get_flags(MDB_env *env, unsigned *arg) { if (unlikely(!env || !arg)) return EINVAL; *arg = env->me_flags & (CHANGEABLE | CHANGELESS); return MDB_SUCCESS; } int __cold mdbx_env_set_userctx(MDB_env *env, void *ctx) { if (unlikely(!env)) return EINVAL; env->me_userctx = ctx; return MDB_SUCCESS; } void *__cold mdbx_env_get_userctx(MDB_env *env) { return env ? env->me_userctx : NULL; } int __cold mdbx_env_set_assert(MDB_env *env, MDB_assert_func *func) { if (unlikely(!env)) return EINVAL; #if MDB_DEBUG env->me_assert_func = func; return MDB_SUCCESS; #else (void)func; return ENOSYS; #endif } int __cold mdbx_env_get_path(MDB_env *env, const char **arg) { if (unlikely(!env || !arg)) return EINVAL; *arg = env->me_path; return MDB_SUCCESS; } int __cold mdbx_env_get_fd(MDB_env *env, int *arg) { if (unlikely(!env || !arg)) return EINVAL; *arg = env->me_fd; return MDB_SUCCESS; } /** Common code for #mdbx_stat() and #mdbx_env_stat(). * @param[in] env the environment to operate in. * @param[in] db the #MDB_db record containing the stats to return. * @param[out] arg the address of an #MDB_stat structure to receive the stats. * @return 0, this function always succeeds. */ static int __cold mdbx_stat0(MDB_env *env, MDB_db *db, MDBX_stat *arg) { arg->ms_psize = env->me_psize; arg->ms_depth = db->md_depth; arg->ms_branch_pages = db->md_branch_pages; arg->ms_leaf_pages = db->md_leaf_pages; arg->ms_overflow_pages = db->md_overflow_pages; arg->ms_entries = db->md_entries; return MDB_SUCCESS; } int __cold mdbx_env_stat(MDB_env *env, MDBX_stat *arg, size_t bytes) { MDB_meta *meta; if (unlikely(env == NULL || arg == NULL)) return EINVAL; if (unlikely(bytes != sizeof(MDBX_stat))) return EINVAL; meta = mdbx_meta_head_r(env); return mdbx_stat0(env, &meta->mm_dbs[MAIN_DBI], arg); } int __cold mdbx_env_info(MDB_env *env, MDBX_envinfo *arg, size_t bytes) { MDB_meta *meta; if (unlikely(env == NULL || arg == NULL)) return EINVAL; if (bytes != sizeof(MDBX_envinfo)) return EINVAL; MDB_meta *m1, *m2; MDB_reader *r; unsigned i; m1 = METAPAGE_1(env); m2 = METAPAGE_2(env); do { meta = mdbx_meta_head_r(env); arg->me_last_txnid = meta->mm_txnid; arg->me_last_pgno = meta->mm_last_pg; arg->me_meta1_txnid = m1->mm_txnid; arg->me_meta1_sign = m1->mm_datasync_sign; arg->me_meta2_txnid = m2->mm_txnid; arg->me_meta2_sign = m2->mm_datasync_sign; } while (unlikely(arg->me_last_txnid != env->me_txns->mti_txnid || arg->me_meta1_sign != m1->mm_datasync_sign || arg->me_meta2_sign != m2->mm_datasync_sign)); arg->me_mapaddr = meta->mm_address; arg->me_mapsize = env->me_mapsize; arg->me_maxreaders = env->me_maxreaders; arg->me_numreaders = env->me_txns->mti_numreaders; arg->me_tail_txnid = 0; r = env->me_txns->mti_readers; arg->me_tail_txnid = arg->me_last_txnid; for (i = 0; i < arg->me_numreaders; ++i) { if (r[i].mr_pid) { txnid_t mr = r[i].mr_txnid; if (arg->me_tail_txnid > mr) arg->me_tail_txnid = mr; } } return MDB_SUCCESS; } static MDB_cmp_func *mdbx_default_keycmp(unsigned flags) { return (flags & MDB_REVERSEKEY) ? mdbx_cmp_memnr : (flags & MDB_INTEGERKEY) ? mdbx_cmp_int_a2 : mdbx_cmp_memn; } static MDB_cmp_func *mdbx_default_datacmp(unsigned flags) { return !(flags & MDB_DUPSORT) ? 0 : ((flags & MDB_INTEGERDUP) ? mdbx_cmp_int_ua : ((flags & MDB_REVERSEDUP) ? mdbx_cmp_memnr : mdbx_cmp_memn)); } /** Set the default comparison functions for a database. * Called immediately after a database is opened to set the defaults. * The user can then override them with #mdbx_set_compare() or * #mdbx_set_dupsort(). * @param[in] txn A transaction handle returned by #mdbx_txn_begin() * @param[in] dbi A database handle returned by #mdbx_dbi_open() */ static void mdbx_default_cmp(MDB_txn *txn, MDB_dbi dbi) { unsigned flags = txn->mt_dbs[dbi].md_flags; txn->mt_dbxs[dbi].md_cmp = mdbx_default_keycmp(flags); txn->mt_dbxs[dbi].md_dcmp = mdbx_default_datacmp(flags); } int mdbx_dbi_open(MDB_txn *txn, const char *name, unsigned flags, MDB_dbi *dbi) { MDB_val key, data; MDB_dbi i; MDB_cursor mc; MDB_db dummy; int rc, dbflag, exact; unsigned unused = 0, seq; char *namedup; size_t len; if (unlikely(!txn || !dbi)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(flags & ~VALID_FLAGS)) return EINVAL; if (unlikely(txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; /* main DB? */ if (!name) { *dbi = MAIN_DBI; if (flags & PERSISTENT_FLAGS) { uint16_t f2 = flags & PERSISTENT_FLAGS; /* make sure flag changes get committed */ if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) { txn->mt_dbs[MAIN_DBI].md_flags |= f2; txn->mt_flags |= MDB_TXN_DIRTY; } } mdbx_default_cmp(txn, MAIN_DBI); return MDB_SUCCESS; } if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) { mdbx_default_cmp(txn, MAIN_DBI); } /* Is the DB already open? */ len = strlen(name); for (i = CORE_DBS; i < txn->mt_numdbs; i++) { if (!txn->mt_dbxs[i].md_name.mv_size) { /* Remember this free slot */ if (!unused) unused = i; continue; } if (len == txn->mt_dbxs[i].md_name.mv_size && !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) { *dbi = i; return MDB_SUCCESS; } } /* If no free slot and max hit, fail */ if (!unused && unlikely(txn->mt_numdbs >= txn->mt_env->me_maxdbs)) return MDB_DBS_FULL; /* Cannot mix named databases with some mainDB flags */ if (unlikely(txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT | MDB_INTEGERKEY))) return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND; /* Find the DB info */ dbflag = DB_NEW | DB_VALID | DB_USRVALID; exact = 0; key.mv_size = len; key.mv_data = (void *)name; mdbx_cursor_init(&mc, txn, MAIN_DBI, NULL); rc = mdbx_cursor_set(&mc, &key, &data, MDB_SET, &exact); if (likely(rc == MDB_SUCCESS)) { /* make sure this is actually a DB */ MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]); if (unlikely((node->mn_flags & (F_DUPDATA | F_SUBDATA)) != F_SUBDATA)) return MDB_INCOMPATIBLE; } else if (!(rc == MDB_NOTFOUND && (flags & MDB_CREATE))) { return rc; } /* Done here so we cannot fail after creating a new DB */ if (unlikely((namedup = strdup(name)) == NULL)) return ENOMEM; if (unlikely(rc)) { /* MDB_NOTFOUND and MDB_CREATE: Create new DB */ data.mv_size = sizeof(MDB_db); data.mv_data = &dummy; memset(&dummy, 0, sizeof(dummy)); dummy.md_root = P_INVALID; dummy.md_flags = flags & PERSISTENT_FLAGS; WITH_CURSOR_TRACKING(mc, rc = mdbx_cursor_put(&mc, &key, &data, F_SUBDATA)); dbflag |= DB_DIRTY; } if (unlikely(rc)) { free(namedup); } else { /* Got info, register DBI in this txn */ unsigned slot = unused ? unused : txn->mt_numdbs; txn->mt_dbxs[slot].md_name.mv_data = namedup; txn->mt_dbxs[slot].md_name.mv_size = len; txn->mt_dbflags[slot] = dbflag; /* txn-> and env-> are the same in read txns, use * tmp variable to avoid undefined assignment */ seq = ++txn->mt_env->me_dbiseqs[slot]; txn->mt_dbiseqs[slot] = seq; memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db)); *dbi = slot; mdbx_default_cmp(txn, slot); if (!unused) { txn->mt_numdbs++; } } return rc; } int __cold mdbx_stat(MDB_txn *txn, MDB_dbi dbi, MDBX_stat *arg, size_t bytes) { if (unlikely(!arg || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_VALID))) return EINVAL; if (unlikely(bytes != sizeof(MDBX_stat))) return EINVAL; if (unlikely(txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; if (unlikely(txn->mt_dbflags[dbi] & DB_STALE)) { MDB_cursor mc; MDB_xcursor mx; /* Stale, must read the DB's root. cursor_init does it for us. */ mdbx_cursor_init(&mc, txn, dbi, &mx); } return mdbx_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg); } void mdbx_dbi_close(MDB_env *env, MDB_dbi dbi) { char *ptr; if (dbi < CORE_DBS || dbi >= env->me_maxdbs) return; ptr = env->me_dbxs[dbi].md_name.mv_data; /* If there was no name, this was already closed */ if (ptr) { env->me_dbxs[dbi].md_name.mv_data = NULL; env->me_dbxs[dbi].md_name.mv_size = 0; env->me_dbflags[dbi] = 0; env->me_dbiseqs[dbi]++; free(ptr); } } int mdbx_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned *flags) { if (unlikely(!txn || !flags)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_VALID))) return EINVAL; *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS; return MDB_SUCCESS; } /** Add all the DB's pages to the free list. * @param[in] mc Cursor on the DB to free. * @param[in] subs non-Zero to check for sub-DBs in this DB. * @return 0 on success, non-zero on failure. */ static int mdbx_drop0(MDB_cursor *mc, int subs) { int rc; rc = mdbx_page_search(mc, NULL, MDB_PS_FIRST); if (likely(rc == MDB_SUCCESS)) { MDB_txn *txn = mc->mc_txn; MDB_node *ni; MDB_cursor mx; unsigned i; /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves. * This also avoids any P_LEAF2 pages, which have no nodes. * Also if the DB doesn't have sub-DBs and has no overflow * pages, omit scanning leaves. */ if ((mc->mc_flags & C_SUB) || (!subs && !mc->mc_db->md_overflow_pages)) mdbx_cursor_pop(mc); mdbx_cursor_copy(mc, &mx); while (mc->mc_snum > 0) { MDB_page *mp = mc->mc_pg[mc->mc_top]; unsigned n = NUMKEYS(mp); if (IS_LEAF(mp)) { for (i = 0; i < n; i++) { ni = NODEPTR(mp, i); if (ni->mn_flags & F_BIGDATA) { MDB_page *omp; pgno_t pg; memcpy(&pg, NODEDATA(ni), sizeof(pg)); rc = mdbx_page_get(mc, pg, &omp, NULL); if (unlikely(rc)) goto done; mdbx_cassert(mc, IS_OVERFLOW(omp)); rc = mdbx_midl_append_range(&txn->mt_free_pgs, pg, omp->mp_pages); if (unlikely(rc)) goto done; mc->mc_db->md_overflow_pages -= omp->mp_pages; if (!mc->mc_db->md_overflow_pages && !subs) break; } else if (subs && (ni->mn_flags & F_SUBDATA)) { mdbx_xcursor_init1(mc, ni); rc = mdbx_drop0(&mc->mc_xcursor->mx_cursor, 0); if (unlikely(rc)) goto done; } } if (!subs && !mc->mc_db->md_overflow_pages) goto pop; } else { if (unlikely((rc = mdbx_midl_need(&txn->mt_free_pgs, n)) != 0)) goto done; for (i = 0; i < n; i++) { pgno_t pg; ni = NODEPTR(mp, i); pg = NODEPGNO(ni); /* free it */ mdbx_midl_xappend(txn->mt_free_pgs, pg); } } if (!mc->mc_top) break; mc->mc_ki[mc->mc_top] = i; rc = mdbx_cursor_sibling(mc, 1); if (rc) { if (unlikely(rc != MDB_NOTFOUND)) goto done; /* no more siblings, go back to beginning * of previous level. */ pop: mdbx_cursor_pop(mc); mc->mc_ki[0] = 0; for (i = 1; i < mc->mc_snum; i++) { mc->mc_ki[i] = 0; mc->mc_pg[i] = mx.mc_pg[i]; } } } /* free it */ rc = mdbx_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root); done: if (unlikely(rc)) txn->mt_flags |= MDB_TXN_ERROR; } else if (rc == MDB_NOTFOUND) { rc = MDB_SUCCESS; } mc->mc_flags &= ~C_INITIALIZED; return rc; } int mdbx_drop(MDB_txn *txn, MDB_dbi dbi, int del) { MDB_cursor *mc, *m2; int rc; if (unlikely(1 < (unsigned)del || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; if (unlikely(TXN_DBI_CHANGED(txn, dbi))) return MDB_BAD_DBI; if (unlikely(F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))) return EACCES; rc = mdbx_cursor_open(txn, dbi, &mc); if (unlikely(rc)) return rc; rc = mdbx_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT); /* Invalidate the dropped DB's cursors */ for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) m2->mc_flags &= ~(C_INITIALIZED | C_EOF); if (unlikely(rc)) goto leave; /* Can't delete the main DB */ if (del && dbi >= CORE_DBS) { rc = mdbx_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA); if (likely(!rc)) { txn->mt_dbflags[dbi] = DB_STALE; mdbx_dbi_close(txn->mt_env, dbi); } else { txn->mt_flags |= MDB_TXN_ERROR; } } else { /* reset the DB record, mark it dirty */ txn->mt_dbflags[dbi] |= DB_DIRTY; txn->mt_dbs[dbi].md_depth = 0; txn->mt_dbs[dbi].md_branch_pages = 0; txn->mt_dbs[dbi].md_leaf_pages = 0; txn->mt_dbs[dbi].md_overflow_pages = 0; txn->mt_dbs[dbi].md_entries = 0; txn->mt_dbs[dbi].md_root = P_INVALID; txn->mt_flags |= MDB_TXN_DIRTY; } leave: mdbx_cursor_close(mc); return rc; } int mdbx_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) { if (unlikely(!txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; txn->mt_dbxs[dbi].md_cmp = cmp; return MDB_SUCCESS; } int mdbx_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) { if (unlikely(!txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; txn->mt_dbxs[dbi].md_dcmp = cmp; return MDB_SUCCESS; } int __cold mdbx_env_get_maxkeysize(MDB_env *env) { if (!env || env->me_signature != MDBX_ME_SIGNATURE) return EINVAL; return ENV_MAXKEY(env); } int __cold mdbx_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx) { unsigned i, rdrs; MDB_reader *mr; char buf[64]; int rc = 0, first = 1; if (unlikely(!env || !func)) return -EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; rdrs = env->me_txns->mti_numreaders; mr = env->me_txns->mti_readers; for (i = 0; i < rdrs; i++) { if (mr[i].mr_pid) { txnid_t txnid = mr[i].mr_txnid; if (txnid == ~(txnid_t)0) sprintf(buf, "%10d %zx -\n", (int)mr[i].mr_pid, (size_t)mr[i].mr_tid); else sprintf(buf, "%10d %zx %zu\n", (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid); if (first) { first = 0; rc = func(" pid thread txnid\n", ctx); if (rc < 0) break; } rc = func(buf, ctx); if (rc < 0) break; } } if (first) { rc = func("(no active readers)\n", ctx); } return rc; } /** Insert pid into list if not already present. * return -1 if already present. */ static int __cold mdbx_pid_insert(pid_t *ids, pid_t pid) { /* binary search of pid in list */ unsigned base = 0; unsigned cursor = 1; int val = 0; unsigned n = ids[0]; while (0 < n) { unsigned pivot = n >> 1; cursor = base + pivot + 1; val = pid - ids[cursor]; if (val < 0) { n = pivot; } else if (val > 0) { base = cursor; n -= pivot + 1; } else { /* found, so it's a duplicate */ return -1; } } if (val > 0) { ++cursor; } ids[0]++; for (n = ids[0]; n > cursor; n--) ids[n] = ids[n - 1]; ids[n] = pid; return 0; } int __cold mdbx_reader_check(MDB_env *env, int *dead) { if (unlikely(!env || env->me_signature != MDBX_ME_SIGNATURE)) return EINVAL; if (dead) *dead = 0; return mdbx_reader_check0(env, 0, dead); } /** As #mdbx_reader_check(). \b rlocked is set if caller locked #me_rmutex. */ static int __cold mdbx_reader_check0(MDB_env *env, int rlocked, int *dead) { pthread_mutex_t *rmutex = rlocked ? NULL : MDB_MUTEX(env, r); unsigned i, j, rdrs; MDB_reader *mr; pid_t *pids, pid; int rc = MDB_SUCCESS, count = 0; if (unlikely(env->me_pid != getpid())) { env->me_flags |= MDB_FATAL_ERROR; return MDB_PANIC; } rdrs = env->me_txns->mti_numreaders; pids = malloc((rdrs + 1) * sizeof(pid_t)); if (!pids) return ENOMEM; pids[0] = 0; mr = env->me_txns->mti_readers; for (i = 0; i < rdrs; i++) { pid = mr[i].mr_pid; if (pid && pid != env->me_pid) { if (mdbx_pid_insert(pids, pid) == 0) { if (!mdbx_reader_pid(env, F_GETLK, pid)) { /* Stale reader found */ j = i; if (rmutex) { if ((rc = pthread_mutex_lock(rmutex)) != 0) { if ((rc = mdbx_mutex_failed(env, rmutex, rc))) break; rdrs = 0; /* the above checked all readers */ } else { /* Recheck, a new process may have reused pid */ if (mdbx_reader_pid(env, F_GETLK, pid)) j = rdrs; } } for (; j < rdrs; j++) { if (mr[j].mr_pid == pid) { mdbx_debug("clear stale reader pid %u txn %zd", (unsigned)pid, mr[j].mr_txnid); mr[j].mr_pid = 0; count++; } } if (rmutex) mdbx_mutex_unlock(env, rmutex); } } } } free(pids); if (dead) *dead = count; return rc; } static int __cold mdbx_mutex_failed(MDB_env *env, pthread_mutex_t *mutex, int rc) { #if MDB_USE_ROBUST if (unlikely(rc == EOWNERDEAD)) { int rlocked, rc2; /* We own the mutex. Clean up after dead previous owner. */ rc = MDB_SUCCESS; rlocked = (mutex == MDB_MUTEX(env, r)); if (!rlocked) { /* Keep mti_txnid updated, otherwise next writer can * overwrite data which latest meta page refers to. * * LY: Hm, how this can happen, if the mti_txnid * is updating only at the finish of a successful commit ? */ MDB_meta *meta = mdbx_meta_head_w(env); assert(env->me_txns->mti_txnid == meta->mm_txnid); (void)meta; /* env is hosed if the dead thread was ours */ if (env->me_txn) { env->me_flags |= MDB_FATAL_ERROR; env->me_txn = NULL; rc = MDB_PANIC; } } mdbx_debug("%cmutex owner died, %s", (rlocked ? 'r' : 'w'), (rc ? "this process' env is hosed" : "recovering")); rc2 = mdbx_reader_check0(env, rlocked, NULL); if (rc2 == 0) rc2 = pthread_mutex_consistent(mutex); if (rc || (rc = rc2)) { mdbx_debug("mutex recovery failed, %s", mdbx_strerror(rc)); pthread_mutex_unlock(mutex); } } #endif /* MDB_USE_ROBUST */ if (unlikely(rc)) { mdbx_debug("lock mutex failed, %s", mdbx_strerror(rc)); if (rc != EDEADLK) { env->me_flags |= MDB_FATAL_ERROR; rc = MDB_PANIC; } } return rc; } static int mdbx_mutex_lock(MDB_env *env, pthread_mutex_t *mutex) { int rc = pthread_mutex_lock(mutex); if (unlikely(rc)) rc = mdbx_mutex_failed(env, mutex, rc); return rc; } static void mdbx_mutex_unlock(MDB_env *env, pthread_mutex_t *mutex) { int rc = pthread_mutex_unlock(mutex); mdbx_assert(env, rc == 0); (void)env; (void)rc; } static unsigned __hot mdbx_midl_search(MDB_IDL ids, MDB_ID id) { /* * binary search of id in ids * if found, returns position of id * if not found, returns first position greater than id */ unsigned base = 0; unsigned cursor = 1; int val = 0; unsigned n = ids[0]; while (0 < n) { unsigned pivot = n >> 1; cursor = base + pivot + 1; val = mdbx_cmp2int(ids[cursor], id); if (val < 0) { n = pivot; } else if (val > 0) { base = cursor; n -= pivot + 1; } else { return cursor; } } if (val > 0) { ++cursor; } return cursor; } static MDB_IDL mdbx_midl_alloc(int num) { MDB_IDL ids = malloc((num + 2) * sizeof(MDB_ID)); if (ids) { *ids++ = num; *ids = 0; } return ids; } static void mdbx_midl_free(MDB_IDL ids) { if (ids) free(ids - 1); } static void mdbx_midl_shrink(MDB_IDL *idp) { MDB_IDL ids = *idp; if (*(--ids) > MDB_IDL_UM_MAX && (ids = realloc(ids, (MDB_IDL_UM_MAX + 2) * sizeof(MDB_ID)))) { *ids++ = MDB_IDL_UM_MAX; *idp = ids; } } static int mdbx_midl_grow(MDB_IDL *idp, int num) { MDB_IDL idn = *idp - 1; /* grow it */ idn = realloc(idn, (*idn + num + 2) * sizeof(MDB_ID)); if (!idn) return ENOMEM; *idn++ += num; *idp = idn; return 0; } static int mdbx_midl_need(MDB_IDL *idp, unsigned num) { MDB_IDL ids = *idp; num += ids[0]; if (num > ids[-1]) { num = (num + num / 4 + (256 + 2)) & -256; if (!(ids = realloc(ids - 1, num * sizeof(MDB_ID)))) return ENOMEM; *ids++ = num - 2; *idp = ids; } return 0; } static int mdbx_midl_append(MDB_IDL *idp, MDB_ID id) { MDB_IDL ids = *idp; /* Too big? */ if (ids[0] >= ids[-1]) { if (mdbx_midl_grow(idp, MDB_IDL_UM_MAX)) return ENOMEM; ids = *idp; } ids[0]++; ids[ids[0]] = id; return 0; } static int mdbx_midl_append_list(MDB_IDL *idp, MDB_IDL app) { MDB_IDL ids = *idp; /* Too big? */ if (ids[0] + app[0] >= ids[-1]) { if (mdbx_midl_grow(idp, app[0])) return ENOMEM; ids = *idp; } memcpy(&ids[ids[0] + 1], &app[1], app[0] * sizeof(MDB_ID)); ids[0] += app[0]; return 0; } static int mdbx_midl_append_range(MDB_IDL *idp, MDB_ID id, unsigned n) { MDB_ID *ids = *idp, len = ids[0]; /* Too big? */ if (len + n > ids[-1]) { if (mdbx_midl_grow(idp, n | MDB_IDL_UM_MAX)) return ENOMEM; ids = *idp; } ids[0] = len + n; ids += len; while (n) ids[n--] = id++; return 0; } static void __hot mdbx_midl_xmerge(MDB_IDL idl, MDB_IDL merge) { MDB_ID old_id, merge_id, i = merge[0], j = idl[0], k = i + j, total = k; idl[0] = (MDB_ID)-1; /* delimiter for idl scan below */ old_id = idl[j]; while (i) { merge_id = merge[i--]; for (; old_id < merge_id; old_id = idl[--j]) idl[k--] = old_id; idl[k--] = merge_id; } idl[0] = total; } /* Quicksort + Insertion sort for small arrays */ #define SMALL 8 #define MIDL_SWAP(a, b) \ { \ itmp = (a); \ (a) = (b); \ (b) = itmp; \ } static void __hot mdbx_midl_sort(MDB_IDL ids) { /* Max possible depth of int-indexed tree * 2 items/level */ int istack[sizeof(int) * CHAR_BIT * 2]; int i, j, k, l, ir, jstack; MDB_ID a, itmp; ir = (int)ids[0]; l = 1; jstack = 0; for (;;) { if (ir - l < SMALL) { /* Insertion sort */ for (j = l + 1; j <= ir; j++) { a = ids[j]; for (i = j - 1; i >= 1; i--) { if (ids[i] >= a) break; ids[i + 1] = ids[i]; } ids[i + 1] = a; } if (jstack == 0) break; ir = istack[jstack--]; l = istack[jstack--]; } else { k = (l + ir) >> 1; /* Choose median of left, center, right */ MIDL_SWAP(ids[k], ids[l + 1]); if (ids[l] < ids[ir]) { MIDL_SWAP(ids[l], ids[ir]); } if (ids[l + 1] < ids[ir]) { MIDL_SWAP(ids[l + 1], ids[ir]); } if (ids[l] < ids[l + 1]) { MIDL_SWAP(ids[l], ids[l + 1]); } i = l + 1; j = ir; a = ids[l + 1]; for (;;) { do i++; while (ids[i] > a); do j--; while (ids[j] < a); if (j < i) break; MIDL_SWAP(ids[i], ids[j]); } ids[l + 1] = ids[j]; ids[j] = a; jstack += 2; if (ir - i + 1 >= j - l) { istack[jstack] = ir; istack[jstack - 1] = i; ir = j - 1; } else { istack[jstack] = j - 1; istack[jstack - 1] = l; l = i; } } } } static unsigned __hot mdbx_mid2l_search(MDB_ID2L ids, MDB_ID id) { /* * binary search of id in ids * if found, returns position of id * if not found, returns first position greater than id */ unsigned base = 0; unsigned cursor = 1; int val = 0; unsigned n = (unsigned)ids[0].mid; while (0 < n) { unsigned pivot = n >> 1; cursor = base + pivot + 1; val = mdbx_cmp2int(id, ids[cursor].mid); if (val < 0) { n = pivot; } else if (val > 0) { base = cursor; n -= pivot + 1; } else { return cursor; } } if (val > 0) { ++cursor; } return cursor; } static int mdbx_mid2l_insert(MDB_ID2L ids, MDB_ID2 *id) { unsigned x, i; x = mdbx_mid2l_search(ids, id->mid); if (x < 1) { /* internal error */ return -2; } if (x <= ids[0].mid && ids[x].mid == id->mid) { /* duplicate */ return -1; } if (ids[0].mid >= MDB_IDL_UM_MAX) { /* too big */ return -2; } else { /* insert id */ ids[0].mid++; for (i = (unsigned)ids[0].mid; i > x; i--) ids[i] = ids[i - 1]; ids[x] = *id; } return 0; } static int mdbx_mid2l_append(MDB_ID2L ids, MDB_ID2 *id) { /* Too big? */ if (ids[0].mid >= MDB_IDL_UM_MAX) { return -2; } ids[0].mid++; ids[ids[0].mid] = *id; return 0; } int __cold mdbx_setup_debug(int flags, MDBX_debug_func *logger, long edge_txn) { unsigned ret = mdbx_runtime_flags; if (flags != (int)MDBX_DBG_DNT) mdbx_runtime_flags = flags; if (logger != (MDBX_debug_func *)MDBX_DBG_DNT) mdbx_debug_logger = logger; if (edge_txn != (long)MDBX_DBG_DNT) { #if MDB_DEBUG mdbx_debug_edge = edge_txn; #endif } return ret; } static txnid_t __cold mdbx_oomkick(MDB_env *env, txnid_t oldest) { int retry; txnid_t snap; mdbx_debug("DB size maxed out"); for (retry = 0;; ++retry) { int reader; if (mdbx_reader_check(env, NULL)) break; snap = mdbx_find_oldest(env, &reader); if (oldest < snap || reader < 0) { if (retry && env->me_oom_func) { /* LY: notify end of oom-loop */ env->me_oom_func(env, 0, 0, oldest, snap - oldest, -retry); } return snap; } MDB_reader *r; pthread_t tid; pid_t pid; int rc; if (!env->me_oom_func) break; r = &env->me_txns->mti_readers[reader]; pid = r->mr_pid; tid = r->mr_tid; if (r->mr_txnid != oldest || pid <= 0) continue; rc = env->me_oom_func(env, pid, (void *)tid, oldest, mdbx_meta_head_w(env)->mm_txnid - oldest, retry); if (rc < 0) break; if (rc) { r->mr_txnid = ~(txnid_t)0; if (rc > 1) { r->mr_tid = 0; r->mr_pid = 0; mdbx_coherent_barrier(); } } } if (retry && env->me_oom_func) { /* LY: notify end of oom-loop */ env->me_oom_func(env, 0, 0, oldest, 0, -retry); } return mdbx_find_oldest(env, NULL); } int __cold mdbx_env_set_syncbytes(MDB_env *env, size_t bytes) { if (unlikely(!env)) return EINVAL; if (unlikely(env->me_signature != MDBX_ME_SIGNATURE)) return MDBX_EBADSIGN; env->me_sync_threshold = bytes; return env->me_map ? mdbx_env_sync(env, 0) : MDB_SUCCESS; } void __cold mdbx_env_set_oomfunc(MDB_env *env, MDBX_oom_func *oomfunc) { if (likely(env && env->me_signature == MDBX_ME_SIGNATURE)) env->me_oom_func = oomfunc; } MDBX_oom_func *__cold mdbx_env_get_oomfunc(MDB_env *env) { return likely(env && env->me_signature == MDBX_ME_SIGNATURE) ? env->me_oom_func : NULL; } ATTRIBUTE_NO_SANITIZE_THREAD /* LY: avoid tsan-trap by me_txn, mm_last_pg and mt_next_pgno */ int mdbx_txn_straggler(MDB_txn *txn, int *percent) { MDB_env *env; MDB_meta *meta; txnid_t lag; if (unlikely(!txn)) return -EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!txn->mt_u.reader)) return -1; env = txn->mt_env; meta = mdbx_meta_head_r(env); if (percent) { size_t maxpg = env->me_maxpg; size_t last = meta->mm_last_pg + 1; if (env->me_txn) last = env->me_txn0->mt_next_pgno; *percent = (last * 100ull + maxpg / 2) / maxpg; } lag = meta->mm_txnid - txn->mt_u.reader->mr_txnid; return (0 > (long)lag) ? ~0u >> 1 : lag; } typedef struct mdbx_walk_ctx { MDB_txn *mw_txn; void *mw_user; MDBX_pgvisitor_func *mw_visitor; } mdbx_walk_ctx_t; /** Depth-first tree traversal. */ static int __cold mdbx_env_walk(mdbx_walk_ctx_t *ctx, const char *dbi, pgno_t pg, int deep) { MDB_page *mp; int rc, i, nkeys; unsigned header_size, unused_size, payload_size, align_bytes; const char *type; if (pg == P_INVALID) return MDB_SUCCESS; /* empty db */ MDB_cursor mc; memset(&mc, 0, sizeof(mc)); mc.mc_snum = 1; mc.mc_txn = ctx->mw_txn; rc = mdbx_page_get(&mc, pg, &mp, NULL); if (rc) return rc; if (pg != mp->mp_p.p_pgno) return MDB_CORRUPTED; nkeys = NUMKEYS(mp); header_size = IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower; unused_size = SIZELEFT(mp); payload_size = 0; /* LY: Don't use mask here, e.g bitwise * (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP). * Pages should not me marked dirty/loose or otherwise. */ switch (mp->mp_flags) { case P_BRANCH: type = "branch"; if (nkeys < 1) return MDB_CORRUPTED; break; case P_LEAF: type = "leaf"; break; case P_LEAF | P_SUBP: type = "dupsort-subleaf"; break; case P_LEAF | P_LEAF2: type = "dupfixed-leaf"; break; case P_LEAF | P_LEAF2 | P_SUBP: type = "dupsort-dupfixed-subleaf"; break; case P_META: case P_OVERFLOW: default: return MDB_CORRUPTED; } for (align_bytes = i = 0; i < nkeys; align_bytes += ((payload_size + align_bytes) & 1), i++) { MDB_node *node; if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */ payload_size += mp->mp_leaf2_ksize; continue; } node = NODEPTR(mp, i); payload_size += NODESIZE + node->mn_ksize; if (IS_BRANCH(mp)) { rc = mdbx_env_walk(ctx, dbi, NODEPGNO(node), deep); if (rc) return rc; continue; } assert(IS_LEAF(mp)); if (node->mn_flags & F_BIGDATA) { MDB_page *omp; pgno_t *opg; size_t over_header, over_payload, over_unused; payload_size += sizeof(pgno_t); opg = NODEDATA(node); rc = mdbx_page_get(&mc, *opg, &omp, NULL); if (rc) return rc; if (*opg != omp->mp_p.p_pgno) return MDB_CORRUPTED; /* LY: Don't use mask here, e.g bitwise * (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP). * Pages should not me marked dirty/loose or otherwise. */ if (P_OVERFLOW != omp->mp_flags) return MDB_CORRUPTED; over_header = PAGEHDRSZ; over_payload = NODEDSZ(node); over_unused = omp->mp_pages * ctx->mw_txn->mt_env->me_psize - over_payload - over_header; rc = ctx->mw_visitor(*opg, omp->mp_pages, ctx->mw_user, dbi, "overflow-data", 1, over_payload, over_header, over_unused); if (rc) return rc; continue; } payload_size += NODEDSZ(node); if (node->mn_flags & F_SUBDATA) { MDB_db *db = NODEDATA(node); char *name = NULL; if (!(node->mn_flags & F_DUPDATA)) { name = NODEKEY(node); int namelen = (char *)db - name; name = memcpy(alloca(namelen + 1), name, namelen); name[namelen] = 0; } rc = mdbx_env_walk(ctx, (name && name[0]) ? name : dbi, db->md_root, deep + 1); if (rc) return rc; } } return ctx->mw_visitor(mp->mp_p.p_pgno, 1, ctx->mw_user, dbi, type, nkeys, payload_size, header_size, unused_size + align_bytes); } int __cold mdbx_env_pgwalk(MDB_txn *txn, MDBX_pgvisitor_func *visitor, void *user) { mdbx_walk_ctx_t ctx; int rc; if (unlikely(!txn)) return MDB_BAD_TXN; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; ctx.mw_txn = txn; ctx.mw_user = user; ctx.mw_visitor = visitor; rc = visitor(0, 2, user, "lmdb", "meta", 2, sizeof(MDB_meta) * 2, PAGEHDRSZ * 2, (txn->mt_env->me_psize - sizeof(MDB_meta) - PAGEHDRSZ) * 2); if (!rc) rc = mdbx_env_walk(&ctx, "free", txn->mt_dbs[FREE_DBI].md_root, 0); if (!rc) rc = mdbx_env_walk(&ctx, "main", txn->mt_dbs[MAIN_DBI].md_root, 0); if (!rc) rc = visitor(P_INVALID, 0, user, NULL, NULL, 0, 0, 0, 0); return rc; } int mdbx_canary_put(MDB_txn *txn, const mdbx_canary *canary) { if (unlikely(!txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))) return EACCES; if (likely(canary)) { txn->mt_canary.x = canary->x; txn->mt_canary.y = canary->y; txn->mt_canary.z = canary->z; } txn->mt_canary.v = txn->mt_txnid; return MDB_SUCCESS; } size_t mdbx_canary_get(MDB_txn *txn, mdbx_canary *canary) { if (unlikely(!txn || txn->mt_signature != MDBX_MT_SIGNATURE)) return 0; if (likely(canary)) *canary = txn->mt_canary; return txn->mt_txnid; } int mdbx_cursor_on_first(MDB_cursor *mc) { if (unlikely(mc == NULL)) return EINVAL; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE)) return MDBX_EBADSIGN; if (!(mc->mc_flags & C_INITIALIZED)) return MDBX_RESULT_FALSE; unsigned i; for (i = 0; i < mc->mc_snum; ++i) { if (mc->mc_ki[i]) return MDBX_RESULT_FALSE; } return MDBX_RESULT_TRUE; } int mdbx_cursor_on_last(MDB_cursor *mc) { if (unlikely(mc == NULL)) return EINVAL; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE)) return MDBX_EBADSIGN; if (!(mc->mc_flags & C_INITIALIZED)) return MDBX_RESULT_FALSE; unsigned i; for (i = 0; i < mc->mc_snum; ++i) { unsigned nkeys = NUMKEYS(mc->mc_pg[i]); if (mc->mc_ki[i] < nkeys - 1) return MDBX_RESULT_FALSE; } return MDBX_RESULT_TRUE; } int mdbx_cursor_eof(MDB_cursor *mc) { if (unlikely(mc == NULL)) return EINVAL; if (unlikely(mc->mc_signature != MDBX_MC_SIGNATURE)) return MDBX_EBADSIGN; if ((mc->mc_flags & C_INITIALIZED) == 0) return MDBX_RESULT_TRUE; if (mc->mc_snum == 0) return MDBX_RESULT_TRUE; if ((mc->mc_flags & C_EOF) && mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top])) return MDBX_RESULT_TRUE; return MDBX_RESULT_FALSE; } static int mdbx_is_samedata(const MDB_val *a, const MDB_val *b) { return a->iov_len == b->iov_len && memcmp(a->iov_base, b->iov_base, a->iov_len) == 0; } /* Позволяет обновить или удалить существующую запись с получением * в old_data предыдущего значения данных. При этом если new_data равен * нулю, то выполняется удаление, иначе обновление/вставка. * * Текущее значение может находиться в уже измененной (грязной) странице. * В этом случае страница будет перезаписана при обновлении, а само старое * значение утрачено. Поэтому исходно в old_data должен быть передан * дополнительный буфер для копирования старого значения. * Если переданный буфер слишком мал, то функция вернет -1, установив * old_data->iov_len в соответствующее значение. * * Для не-уникальных ключей также возможен второй сценарий использования, * когда посредством old_data из записей с одинаковым ключом для * удаления/обновления выбирается конкретная. Для выбора этого сценария * во flags следует одновременно указать MDB_CURRENT и MDB_NOOVERWRITE. * Именно эта комбинация выбрана, так как она лишена смысла, и этим позволяет * идентифицировать запрос такого сценария. * * Функция может быть замещена соответствующими операциями с курсорами * после двух доработок (TODO): * - внешняя аллокация курсоров, в том числе на стеке (без malloc). * - получения статуса страницы по адресу (знать о P_DIRTY). */ int mdbx_replace(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *new_data, MDB_val *old_data, unsigned flags) { MDB_cursor mc; MDB_xcursor mx; if (unlikely(!key || !old_data || !txn || old_data == new_data)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(old_data->iov_base == NULL && old_data->iov_len)) return EINVAL; if (unlikely(new_data == NULL && !(flags & MDB_CURRENT))) return EINVAL; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; if (unlikely(flags & ~(MDB_NOOVERWRITE | MDB_NODUPDATA | MDB_RESERVE | MDB_APPEND | MDB_APPENDDUP | MDB_CURRENT))) return EINVAL; if (unlikely(txn->mt_flags & (MDB_TXN_RDONLY | MDB_TXN_BLOCKED))) return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN; mdbx_cursor_init(&mc, txn, dbi, &mx); mc.mc_next = txn->mt_cursors[dbi]; txn->mt_cursors[dbi] = &mc; int rc; MDB_val present_key = *key; if (F_ISSET(flags, MDB_CURRENT | MDB_NOOVERWRITE)) { /* в old_data значение для выбора конкретного дубликата */ if (unlikely(!(txn->mt_dbs[dbi].md_flags & MDB_DUPSORT))) { rc = EINVAL; goto bailout; } /* убираем лишний бит, он был признаком запрошенного режима */ flags -= MDB_NOOVERWRITE; rc = mdbx_cursor_get(&mc, &present_key, old_data, MDB_GET_BOTH); if (rc != MDB_SUCCESS) goto bailout; if (new_data) { /* обновление конкретного дубликата */ if (mdbx_is_samedata(old_data, new_data)) /* если данные совпадают, то ничего делать не надо */ goto bailout; #if 0 /* LY: исправлено в mdbx_cursor_put(), здесь в качестве памятки */ MDB_node *leaf = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA) && mc.mc_xcursor->mx_db.md_entries > 1) { /* Если у ключа больше одного значения, то * сначала удаляем найденое "старое" значение. * * Этого можно не делать, так как MDBX уже * обучен корректно обрабатывать такие ситуации. * * Однако, следует помнить, что в LMDB при * совпадении размера данных, значение будет * просто перезаписано с нарушением * упорядоченности, что сломает поиск. */ rc = mdbx_cursor_del(&mc, 0); if (rc != MDB_SUCCESS) goto bailout; flags -= MDB_CURRENT; } #endif } } else { /* в old_data буфер для сохранения предыдущего значения */ if (unlikely(new_data && old_data->iov_base == new_data->iov_base)) return EINVAL; MDB_val present_data; rc = mdbx_cursor_get(&mc, &present_key, &present_data, MDB_SET_KEY); if (unlikely(rc != MDB_SUCCESS)) { old_data->iov_base = NULL; old_data->iov_len = rc; if (rc != MDB_NOTFOUND || (flags & MDB_CURRENT)) goto bailout; } else if (flags & MDB_NOOVERWRITE) { rc = MDB_KEYEXIST; *old_data = present_data; goto bailout; } else { MDB_page *page = mc.mc_pg[mc.mc_top]; if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { if (flags & MDB_CURRENT) { /* для не-уникальных ключей позволяем update/delete только если ключ * один */ MDB_node *leaf = NODEPTR(page, mc.mc_ki[mc.mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_tassert(txn, XCURSOR_INITED(&mc) && mc.mc_xcursor->mx_db.md_entries > 1); if (mc.mc_xcursor->mx_db.md_entries > 1) { rc = MDBX_EMULTIVAL; goto bailout; } } /* если данные совпадают, то ничего делать не надо */ if (new_data && mdbx_is_samedata(&present_data, new_data)) { *old_data = *new_data; goto bailout; } /* В оригинальной LMDB фладок MDB_CURRENT здесь приведет * к замене данных без учета MDB_DUPSORT сортировки, * но здесь это в любом случае допустимо, так как мы * проверили что для ключа есть только одно значение. */ } else if ((flags & MDB_NODUPDATA) && mdbx_is_samedata(&present_data, new_data)) { /* если данные совпадают и установлен MDB_NODUPDATA */ rc = MDB_KEYEXIST; goto bailout; } } else { /* если данные совпадают, то ничего делать не надо */ if (new_data && mdbx_is_samedata(&present_data, new_data)) { *old_data = *new_data; goto bailout; } flags |= MDB_CURRENT; } if (page->mp_flags & P_DIRTY) { if (unlikely(old_data->iov_len < present_data.iov_len)) { old_data->iov_base = NULL; old_data->iov_len = present_data.iov_len; rc = MDBX_RESULT_TRUE; goto bailout; } memcpy(old_data->iov_base, present_data.iov_base, present_data.iov_len); old_data->iov_len = present_data.iov_len; } else { *old_data = present_data; } } } if (likely(new_data)) rc = mdbx_cursor_put(&mc, key, new_data, flags); else rc = mdbx_cursor_del(&mc, 0); bailout: txn->mt_cursors[dbi] = mc.mc_next; return rc; } int mdbx_get_ex(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, int *values_count) { DKBUF; mdbx_debug("===> get db %u key [%s]", dbi, DKEY(key)); if (unlikely(!key || !data || !txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))) return EINVAL; if (unlikely(txn->mt_flags & MDB_TXN_BLOCKED)) return MDB_BAD_TXN; MDB_cursor mc; MDB_xcursor mx; mdbx_cursor_init(&mc, txn, dbi, &mx); int exact = 0; int rc = mdbx_cursor_set(&mc, key, data, MDB_SET_KEY, &exact); if (unlikely(rc != MDB_SUCCESS)) { if (rc == MDB_NOTFOUND && values_count) *values_count = 0; return rc; } if (values_count) { *values_count = 1; if (mc.mc_xcursor != NULL) { MDB_node *leaf = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdbx_tassert(txn, mc.mc_xcursor == &mx && (mx.mx_cursor.mc_flags & C_INITIALIZED)); *values_count = mx.mx_db.md_entries; } } } return MDB_SUCCESS; } /* Функция сообщает находится ли указанный адрес в "грязной" странице у * заданной пишущей транзакции. В конечном счете это позволяет избавиться от * лишнего копирования данных из НЕ-грязных страниц. * * "Грязные" страницы - это те, которые уже были изменены в ходе пишущей * транзакции. Соответственно, какие-либо дальнейшие изменения могут привести * к перезаписи таких страниц. Поэтому все функции, выполняющие изменения, в * качестве аргументов НЕ должны получать указатели на данные в таких * страницах. В свою очередь "НЕ грязные" страницы перед модификацией будут * скопированы. * * Другими словами, данные из "грязных" страниц должны быть либо скопированы * перед передачей в качестве аргументов для дальнейших модификаций, либо * отвергнуты на стадии проверки корректности аргументов. * * Таким образом, функция позволяет как избавится от лишнего копирования, * так и выполнить более полную проверку аргументов. * * ВАЖНО: Передаваемый указатель должен указывать на начало данных. Только * так гарантируется что актуальный заголовок страницы будет физически * расположен в той-же странице памяти, в том числе для многостраничных * P_OVERFLOW страниц с длинными данными. */ int mdbx_is_dirty(const MDB_txn *txn, const void *ptr) { if (unlikely(!txn)) return EINVAL; if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE)) return MDBX_EBADSIGN; if (unlikely(txn->mt_flags & MDB_TXN_RDONLY)) return MDB_BAD_TXN; const MDB_env *env = txn->mt_env; const uintptr_t mask = ~(uintptr_t)(env->me_psize - 1); const MDB_page *page = (const MDB_page *)((uintptr_t)ptr & mask); /* LY: Тут не всё хорошо с абсолютной достоверностью результата, * так как флажок P_DIRTY в LMDB может означать не совсем то, * что было исходно задумано, детали см в логике кода mdbx_page_touch(). * * Более того, в режиме БЕЗ WRITEMAP грязные страницы выделяются через * malloc(), т.е. находятся вне mmap-диаппазона. * * Тем не менее, однозначно страница "не грязная" если: * - адрес находится внутри mmap-диаппазона и в заголовке страницы * нет флажка P_DIRTY, то однозначно страница "не грязная". * - адрес вне mmap-диаппазона и его нет среди списка "грязных" страниц. */ if (env->me_map < (char *)page) { const size_t used_size = env->me_psize * txn->mt_next_pgno; if (env->me_map + used_size > (char *)page) { /* страница внутри диапазона */ if (page->mp_flags & P_DIRTY) return MDBX_RESULT_TRUE; return MDBX_RESULT_FALSE; } /* Гипотетически здесь возможна ситуация, когда указатель адресует что-то * в пределах mmap, но за границей распределенных страниц. Это тяжелая * ошибка, которой не возможно добиться без каких-то мега-нарушений. * Поэтому не проверяем этот случай кроме как assert-ом, ибо бестолку. */ mdbx_tassert(txn, env->me_map + env->me_mapsize > (char *)page); } /* Страница вне mmap-диаппазона */ if (env->me_flags & MDB_WRITEMAP) /* Если MDB_WRITEMAP, то результат уже ясен. */ return MDBX_RESULT_FALSE; /* Смотрим список грязных страниц у заданной транзакции. */ MDB_ID2 *list = txn->mt_u.dirty_list; if (list) { unsigned i, n = list[0].mid; for (i = 1; i <= n; i++) { const MDB_page *dirty = list[i].mptr; if (dirty == page) return MDBX_RESULT_TRUE; } } /* При вложенных транзакциях, страница может быть в dirty-списке * родительской транзакции, но в этом случае она будет скопирована перед * изменением в текущей транзакции, т.е. относительно заданной транзакции * проверяемый адрес "не грязный". */ return MDBX_RESULT_FALSE; } int mdbx_dbi_open_ex(MDB_txn *txn, const char *name, unsigned flags, MDB_dbi *pdbi, MDB_cmp_func *keycmp, MDB_cmp_func *datacmp) { int rc = mdbx_dbi_open(txn, name, flags, pdbi); if (likely(rc == MDB_SUCCESS)) { MDB_dbi dbi = *pdbi; unsigned flags = txn->mt_dbs[dbi].md_flags; txn->mt_dbxs[dbi].md_cmp = keycmp ? keycmp : mdbx_default_keycmp(flags); txn->mt_dbxs[dbi].md_dcmp = datacmp ? datacmp : mdbx_default_datacmp(flags); } return rc; }