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OpenLDAP 2.4.40
2015-01-07 16:49:50 +03:00
/** @file mdb.c
* @brief Lightning memory-mapped database library
*
* A Btree-based database management library modeled loosely on the
* BerkeleyDB API, but much simplified.
*/
/*
* Copyright 2011-2014 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
* <http://www.OpenLDAP.org/license.html>.
*
* This code is derived from btree.c written by Martin Hedenfalk.
*
* Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
*
* 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 1
#endif
#ifdef _WIN32
#include <malloc.h>
#include <windows.h>
/** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
* as int64 which is wrong. MSVC doesn't define it at all, so just
* don't use it.
*/
#define MDB_PID_T int
#define MDB_THR_T DWORD
#include <sys/types.h>
#include <sys/stat.h>
#ifdef __GNUC__
# include <sys/param.h>
#else
# define LITTLE_ENDIAN 1234
# define BIG_ENDIAN 4321
# define BYTE_ORDER LITTLE_ENDIAN
# ifndef SSIZE_MAX
# define SSIZE_MAX INT_MAX
# endif
#endif
#else
#include <sys/types.h>
#include <sys/stat.h>
#define MDB_PID_T pid_t
#define MDB_THR_T pthread_t
#include <sys/param.h>
#include <sys/uio.h>
#include <sys/mman.h>
#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#include <fcntl.h>
#endif
#if defined(__mips) && defined(__linux)
/* MIPS has cache coherency issues, requires explicit cache control */
#include <asm/cachectl.h>
extern int cacheflush(char *addr, int nbytes, int cache);
#define CACHEFLUSH(addr, bytes, cache) cacheflush(addr, bytes, cache)
#else
#define CACHEFLUSH(addr, bytes, cache)
#endif
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#if defined(__sun)
/* Most platforms have posix_memalign, older may only have memalign */
#define HAVE_MEMALIGN 1
#include <malloc.h>
#endif
#if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
#include <netinet/in.h>
#include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
#endif
#if defined(__APPLE__) || defined (BSD)
# define MDB_USE_POSIX_SEM 1
# define MDB_FDATASYNC fsync
#elif defined(ANDROID)
# define MDB_FDATASYNC fsync
#endif
#ifndef _WIN32
#include <pthread.h>
#ifdef MDB_USE_POSIX_SEM
# define MDB_USE_HASH 1
#include <semaphore.h>
#endif
#endif
#ifdef USE_VALGRIND
#include <valgrind/memcheck.h>
#define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
#define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
#define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
#define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
#define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
#else
#define VGMEMP_CREATE(h,r,z)
#define VGMEMP_ALLOC(h,a,s)
#define VGMEMP_FREE(h,a)
#define VGMEMP_DESTROY(h)
#define VGMEMP_DEFINED(a,s)
#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
#include "lmdb.h"
#include "midl.h"
#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
#ifdef __GNUC__
/** Put infrequently used env functions in separate section */
# ifdef __APPLE__
# define ESECT __attribute__ ((section("__TEXT,text_env")))
# else
# define ESECT __attribute__ ((section("text_env")))
# endif
#else
#define ESECT
#endif
/** @defgroup internal LMDB Internals
* @{
*/
/** @defgroup compat Compatibility Macros
* A bunch of macros to minimize the amount of platform-specific ifdefs
* needed throughout the rest of the code. When the features this library
* needs are similar enough to POSIX to be hidden in a one-or-two line
* replacement, this macro approach is used.
* @{
*/
/** Features under development */
#ifndef MDB_DEVEL
#define MDB_DEVEL 0
#endif
/** Wrapper around __func__, which is a C99 feature */
#if __STDC_VERSION__ >= 199901L
# define mdb_func_ __func__
#elif __GNUC__ >= 2 || _MSC_VER >= 1300
# define mdb_func_ __FUNCTION__
#else
/* If a debug message says <mdb_unknown>(), update the #if statements above */
# define mdb_func_ "<mdb_unknown>"
#endif
#ifdef _WIN32
#define MDB_USE_HASH 1
#define MDB_PIDLOCK 0
#define THREAD_RET DWORD
#define pthread_t HANDLE
#define pthread_mutex_t HANDLE
#define pthread_cond_t HANDLE
#define pthread_key_t DWORD
#define pthread_self() GetCurrentThreadId()
#define pthread_key_create(x,y) \
((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
#define pthread_key_delete(x) TlsFree(x)
#define pthread_getspecific(x) TlsGetValue(x)
#define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
#define pthread_mutex_unlock(x) ReleaseMutex(*x)
#define pthread_mutex_lock(x) WaitForSingleObject(*x, INFINITE)
#define pthread_cond_signal(x) SetEvent(*x)
#define pthread_cond_wait(cond,mutex) do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
#define THREAD_CREATE(thr,start,arg) thr=CreateThread(NULL,0,start,arg,0,NULL)
#define THREAD_FINISH(thr) WaitForSingleObject(thr, INFINITE)
#define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_rmutex)
#define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_rmutex)
#define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_wmutex)
#define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_wmutex)
#define getpid() GetCurrentProcessId()
#define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
#define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
#define ErrCode() GetLastError()
#define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
#define close(fd) (CloseHandle(fd) ? 0 : -1)
#define munmap(ptr,len) UnmapViewOfFile(ptr)
#ifdef PROCESS_QUERY_LIMITED_INFORMATION
#define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
#else
#define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
#endif
#define Z "I"
#else
#define THREAD_RET void *
#define THREAD_CREATE(thr,start,arg) pthread_create(&thr,NULL,start,arg)
#define THREAD_FINISH(thr) pthread_join(thr,NULL)
#define Z "z" /**< printf format modifier for size_t */
/** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
#define MDB_PIDLOCK 1
#ifdef MDB_USE_POSIX_SEM
#define LOCK_MUTEX_R(env) mdb_sem_wait((env)->me_rmutex)
#define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex)
#define LOCK_MUTEX_W(env) mdb_sem_wait((env)->me_wmutex)
#define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex)
static int
mdb_sem_wait(sem_t *sem)
{
int rc;
while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
return rc;
}
#else
/** Lock the reader mutex.
*/
#define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
/** Unlock the reader mutex.
*/
#define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
/** Lock the writer mutex.
* Only a single write transaction is allowed at a time. Other writers
* will block waiting for this mutex.
*/
#define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
/** Unlock the writer mutex.
*/
#define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
#endif /* MDB_USE_POSIX_SEM */
/** Get the error code for the last failed system function.
*/
#define ErrCode() errno
/** 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))
#endif
#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
#define MNAME_LEN 32
#else
#define MNAME_LEN (sizeof(pthread_mutex_t))
#endif
/** @} */
#ifndef _WIN32
/** A flag for opening a file and requesting synchronous data writes.
* This is only used when writing a meta page. It's not strictly needed;
* we could just do a normal write and then immediately perform a flush.
* But if this flag is available it saves us an extra system call.
*
* @note If O_DSYNC is undefined but exists in /usr/include,
* preferably set some compiler flag to get the definition.
* Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
*/
#ifndef MDB_DSYNC
# define MDB_DSYNC O_DSYNC
#endif
#endif
/** Function for flushing the data of a file. Define this to fsync
* if fdatasync() is not supported.
*/
#ifndef MDB_FDATASYNC
# define MDB_FDATASYNC fdatasync
#endif
#ifndef MDB_MSYNC
# define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
#endif
#ifndef MS_SYNC
#define MS_SYNC 1
#endif
#ifndef MS_ASYNC
#define MS_ASYNC 0
#endif
/** 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
* @{
*/
#ifndef MDB_DEBUG
/** Enable debug output. Needs variable argument macros (a C99 feature).
* Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
* read from and written to the database (used for free space management).
*/
#define MDB_DEBUG 0
#endif
#if MDB_DEBUG
static int mdb_debug;
static txnid_t mdb_debug_start;
/** Print a debug message with printf formatting.
* Requires double parenthesis around 2 or more args.
*/
# define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
# define DPRINTF0(fmt, ...) \
fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
#else
# define DPRINTF(args) ((void) 0)
#endif
/** Print a debug string.
* The string is printed literally, with no format processing.
*/
#define DPUTS(arg) DPRINTF(("%s", arg))
/** 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 1
/** @brief The max size of a key we can write, or 0 for dynamic max.
*
* Define this as 0 to compute the max from the page size. 511
* is default for backwards compat: liblmdb <= 0.9.10 can break
* when modifying a DB with keys/dupsort data bigger than its max.
* #MDB_DEVEL sets the default to 0.
*
* 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)
#endif
/** @brief The maximum size of a data item.
*
* We only store a 32 bit value for node sizes.
*/
#define MAXDATASIZE 0xffffffffUL
#if MDB_DEBUG
/** 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) mdb_dkey(x, kbuf)
#else
#define DKBUF
#define DKEY(x) 0
#endif
/** 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 #mdb_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 #mdb_env_set_maxreaders().
*/
#define DEFAULT_READERS 126
/** The size of a CPU cache line in bytes. We want our lock structures
* aligned to this size to avoid false cache line sharing in the
* lock table.
* This value works for most CPUs. For Itanium this should be 128.
*/
#ifndef CACHELINE
#define CACHELINE 64
#endif
/** 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.
*/
txnid_t mrb_txnid;
/** The process ID of the process owning this reader txn. */
MDB_PID_T mrb_pid;
/** The thread ID of the thread owning this txn. */
MDB_THR_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-1) & ~(CACHELINE-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;
#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
char mtb_rmname[MNAME_LEN];
#else
/** Mutex protecting access to this table.
* This is the reader lock that #LOCK_MUTEX_R acquires.
*/
pthread_mutex_t mtb_mutex;
#endif
/** 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.
*/
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.
*/
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_mutex mt1.mtb.mtb_mutex
#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-1) & ~(CACHELINE-1)];
} mt1;
union {
#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
char mt2_wmname[MNAME_LEN];
#define mti_wmname mt2.mt2_wmname
#else
pthread_mutex_t mt2_wmutex;
#define mti_wmutex mt2.mt2_wmutex
#endif
char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-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 */ \
+ (((MDB_PIDLOCK) != 0) << 16)))
/** @} */
/** Common header for all page types.
* Overflow records occupy a number of contiguous pages with no
* headers on any page after the first.
*/
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_pad;
/** @defgroup mdb_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 mdb_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 METADATA(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 */
#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.
*/
typedef struct MDB_node {
/** lo and hi are used for data size on leaf nodes and for
* child pgno on branch nodes. On 64 bit platforms, flags
* is also used for pgno. (Branch nodes have no flags).
* They are in host byte order in case that lets some
* accesses be optimized into a 32-bit word access.
*/
#if BYTE_ORDER == LITTLE_ENDIAN
unsigned short mn_lo, mn_hi; /**< part of data size or pgno */
#else
unsigned short mn_hi, mn_lo;
#endif
/** @defgroup mdb_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 #mdb_node_add() */
#define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
/** @} */
unsigned short mn_flags; /**< @ref mdb_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) ((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
#else
#if 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
#endif
/** 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_pad; /**< also ksize for LEAF2 pages */
uint16_t md_flags; /**< @ref mdb_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;
/** mdb_dbi_open flags */
#define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
#define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
#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
/** 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 lock 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[2]; /**< first is free space, 2nd is main db */
/** The size of pages used in this DB */
#define mm_psize mm_dbs[0].md_pad
/** Any persistent environment flags. @ref mdb_env */
#define mm_flags mm_dbs[0].md_flags
pgno_t mm_last_pg; /**< last used page in file */
txnid_t mm_txnid; /**< txnid that committed this page */
} 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_rel_func *md_rel; /**< user relocate function */
void *md_relctx; /**< user-provided context for md_rel */
} MDB_dbx;
/** A database transaction.
* Every operation requires a transaction handle.
*/
struct MDB_txn {
MDB_txn *mt_parent; /**< parent of a nested txn */
MDB_txn *mt_child; /**< nested txn under this txn */
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 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 int *mt_dbiseqs;
/** @defgroup mt_dbflag Transaction DB Flags
* @ingroup internal
* @{
*/
#define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
#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 */
/** @} */
/** 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. This number only ever increments;
* we don't decrement it when individual DB handles are closed.
*/
MDB_dbi mt_numdbs;
/** @defgroup mdb_txn Transaction Flags
* @ingroup internal
* @{
*/
#define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
#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 */
/** @} */
unsigned int mt_flags; /**< @ref mdb_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 int mt_dirty_room;
};
/** 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 {
/** 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 mdb_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_SPLITTING 0x20 /**< Cursor is in page_split */
#define C_UNTRACK 0x40 /**< Un-track cursor when closing */
/** @} */
unsigned int mc_flags; /**< @ref mdb_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;
/** 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;
/** The database environment. */
struct MDB_env {
HANDLE me_fd; /**< The main data file */
HANDLE me_lfd; /**< The lock file */
HANDLE me_mfd; /**< just for writing the meta pages */
/** 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 mdb_env */
unsigned int me_psize; /**< DB page size, inited from me_os_psize */
unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
unsigned int me_maxreaders; /**< size of the reader table */
unsigned int me_numreaders; /**< max numreaders set by this env */
MDB_dbi me_numdbs; /**< number of DBs opened */
MDB_dbi me_maxdbs; /**< size of the DB table */
MDB_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 or NULL */
MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
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 */
off_t me_size; /**< current file size */
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 int *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 */
int me_maxfree_1pg;
/** Max size of a node on a page */
unsigned int me_nodemax;
#if !(MDB_MAXKEYSIZE)
unsigned int me_maxkey; /**< max size of a key */
#endif
int me_live_reader; /**< have liveness lock in reader table */
#ifdef _WIN32
int me_pidquery; /**< Used in OpenProcess */
HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
HANDLE me_wmutex;
#elif defined(MDB_USE_POSIX_SEM)
sem_t *me_rmutex; /* Shared mutexes are not supported */
sem_t *me_wmutex;
#endif
void *me_userctx; /**< User-settable context */
MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
};
/** 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) \
((txn) && (dbi) < (txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & DB_VALID))
/** Check for misused \b dbi handles */
#define TXN_DBI_CHANGED(txn, dbi) \
((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
static int mdb_page_touch(MDB_cursor *mc);
static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
static int mdb_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 mdb_page_search(MDB_cursor *mc,
MDB_val *key, int flags);
static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
#define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
pgno_t newpgno, unsigned int nflags);
static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
static int mdb_env_pick_meta(const MDB_env *env);
static int mdb_env_write_meta(MDB_txn *txn);
#if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
# define mdb_env_close0(env, excl) mdb_env_close1(env)
#endif
static void mdb_env_close0(MDB_env *env, int excl);
static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
static int mdb_node_add(MDB_cursor *mc, indx_t indx,
MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
static void mdb_node_del(MDB_cursor *mc, int ksize);
static void mdb_node_shrink(MDB_page *mp, indx_t indx);
static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
static int mdb_rebalance(MDB_cursor *mc);
static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
static void mdb_cursor_pop(MDB_cursor *mc);
static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
static int mdb_cursor_del0(MDB_cursor *mc);
static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
int *exactp);
static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
static void mdb_xcursor_init0(MDB_cursor *mc);
static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
static int mdb_drop0(MDB_cursor *mc, int subs);
static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
/** @cond */
static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
/** @endcond */
#ifdef _WIN32
static SECURITY_DESCRIPTOR mdb_null_sd;
static SECURITY_ATTRIBUTES mdb_all_sa;
static int mdb_sec_inited;
#endif
/** Return the library version info. */
char *
mdb_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;
}
/** Table of descriptions for LMDB @ref errors */
static char *const mdb_errstr[] = {
"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 type",
"MDB_PANIC: Update of meta page failed",
"MDB_VERSION_MISMATCH: Database environment version mismatch",
"MDB_INVALID: File is not an LMDB file",
"MDB_MAP_FULL: Environment mapsize limit reached",
"MDB_DBS_FULL: Environment maxdbs limit reached",
"MDB_READERS_FULL: Environment maxreaders limit reached",
"MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
"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 cannot recover - it must be aborted",
"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",
};
char *
mdb_strerror(int err)
{
#ifdef _WIN32
/** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
* This works as long as no function between the call to mdb_strerror
* and the actual use of the message uses more than 4K of stack.
*/
char pad[4096];
char buf[1024], *ptr = buf;
#endif
int i;
if (!err)
return ("Successful return: 0");
if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
i = err - MDB_KEYEXIST;
return mdb_errstr[i];
}
#ifdef _WIN32
/* These are the C-runtime error codes we use. The comment indicates
* their numeric value, and the Win32 error they would correspond to
* if the error actually came from a Win32 API. A major mess, we should
* have used LMDB-specific error codes for everything.
*/
switch(err) {
case ENOENT: /* 2, FILE_NOT_FOUND */
case EIO: /* 5, ACCESS_DENIED */
case ENOMEM: /* 12, INVALID_ACCESS */
case EACCES: /* 13, INVALID_DATA */
case EBUSY: /* 16, CURRENT_DIRECTORY */
case EINVAL: /* 22, BAD_COMMAND */
case ENOSPC: /* 28, OUT_OF_PAPER */
return strerror(err);
default:
;
}
buf[0] = 0;
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, err, 0, ptr, sizeof(buf), pad);
return ptr;
#else
return strerror(err);
#endif
}
/** assert(3) variant in cursor context */
#define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
/** assert(3) variant in transaction context */
#define mdb_tassert(mc, expr) mdb_assert0((txn)->mt_env, expr, #expr)
/** assert(3) variant in environment context */
#define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
#ifndef NDEBUG
# define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
static void
mdb_assert_fail(MDB_env *env, const char *expr_txt,
const char *func, const char *file, int line)
{
char buf[400];
sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
file, line, expr_txt, func);
if (env->me_assert_func)
env->me_assert_func(env, buf);
fprintf(stderr, "%s\n", buf);
abort();
}
#else
# define mdb_assert0(env, expr, expr_txt) ((void) 0)
#endif /* NDEBUG */
#if MDB_DEBUG
/** Return the page number of \b mp which may be sub-page, for debug output */
static pgno_t
mdb_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 *
mdb_dkey(MDB_val *key, char *buf)
{
char *ptr = buf;
unsigned char *c = key->mv_data;
unsigned int 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", *c++);
#else
sprintf(buf, "%.*s", key->mv_size, key->mv_data);
#endif
return buf;
}
static const char *
mdb_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. */
void
mdb_page_list(MDB_page *mp)
{
pgno_t pgno = mdb_dbg_pgno(mp);
const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
MDB_node *node;
unsigned int 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:
fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
pgno, mp->mp_pages, state);
return;
case P_META:
fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
return;
default:
fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
return;
}
nkeys = NUMKEYS(mp);
fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
for (i=0; i<nkeys; i++) {
if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
key.mv_size = nsize = mp->mp_pad;
key.mv_data = LEAF2KEY(mp, i, nsize);
total += nsize;
fprintf(stderr, "key %d: nsize %d, %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)) {
fprintf(stderr, "key %d: page %"Z"u, %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);
fprintf(stderr, "key %d: nsize %d, %s%s\n",
i, nsize, DKEY(&key), mdb_leafnode_type(node));
}
total = EVEN(total);
}
fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
}
void
mdb_cursor_chk(MDB_cursor *mc)
{
unsigned int i;
MDB_node *node;
MDB_page *mp;
if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
for (i=0; i<mc->mc_top; i++) {
mp = mc->mc_pg[i];
node = NODEPTR(mp, mc->mc_ki[i]);
if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
printf("oops!\n");
}
if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
printf("ack!\n");
}
#endif
#if (MDB_DEBUG) > 2
/** 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 mdb_audit(MDB_txn *txn)
{
MDB_cursor mc;
MDB_val key, data;
MDB_ID freecount, count;
MDB_dbi i;
int rc;
freecount = 0;
mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
freecount += *(MDB_ID *)data.mv_data;
mdb_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;
mdb_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 = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
for (; rc == MDB_SUCCESS; rc = mdb_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;
}
}
}
mdb_tassert(txn, rc == MDB_NOTFOUND);
}
}
if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
}
}
#endif
int
mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
{
return txn->mt_dbxs[dbi].md_cmp(a, b);
}
int
mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
{
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.
*/
static MDB_page *
mdb_page_malloc(MDB_txn *txn, unsigned num)
{
MDB_env *env = txn->mt_env;
MDB_page *ret = env->me_dpages;
size_t psize = env->me_psize, sz = psize, off;
/* For ! #MDB_NOMEMINIT, psize counts how much to init.
* 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.
*/
if (num == 1) {
if (ret) {
VGMEMP_ALLOC(env, ret, sz);
VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
env->me_dpages = ret->mp_next;
return ret;
}
psize -= off = PAGEHDRSZ;
} else {
sz *= num;
off = sz - psize;
}
if ((ret = malloc(sz)) != NULL) {
VGMEMP_ALLOC(env, ret, sz);
if (!(env->me_flags & MDB_NOMEMINIT)) {
memset((char *)ret + off, 0, psize);
ret->mp_pad = 0;
}
} else {
txn->mt_flags |= MDB_TXN_ERROR;
}
return ret;
}
/** Free a single page.
* Saves single pages to a list, for future reuse.
* (This is not used for multi-page overflow pages.)
*/
static void
mdb_page_free(MDB_env *env, MDB_page *mp)
{
mp->mp_next = env->me_dpages;
VGMEMP_FREE(env, mp);
env->me_dpages = mp;
}
/** Free a dirty page */
static void
mdb_dpage_free(MDB_env *env, MDB_page *dp)
{
if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
mdb_page_free(env, dp);
} else {
/* large pages just get freed directly */
VGMEMP_FREE(env, dp);
free(dp);
}
}
/** Return all dirty pages to dpage list */
static void
mdb_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++) {
mdb_dpage_free(env, dl[i].mptr);
}
dl[0].mid = 0;
}
/** 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
mdb_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 = mdb_mid2l_search(dl, pgno);
if (x <= dl[0].mid && dl[x].mid == pgno) {
if (mp != dl[x].mptr) { /* bad cursor? */
mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
txn->mt_flags |= MDB_TXN_ERROR;
return MDB_CORRUPTED;
}
/* ok, it's ours */
loose = 1;
}
}
} else {
/* no parent txn, so it's just ours */
loose = 1;
}
}
if (loose) {
DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
mp->mp_pgno));
NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
txn->mt_loose_pgs = mp;
txn->mt_loose_count++;
mp->mp_flags |= P_LOOSE;
} else {
int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
if (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 #mdb_page_flush().
* @return 0 on success, non-zero on failure.
*/
static int
mdb_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;
MDB_xcursor *mx;
MDB_page *dp, *mp;
MDB_node *leaf;
unsigned i, j;
int rc = MDB_SUCCESS, level;
/* Mark pages seen by cursors */
if (mc->mc_flags & C_UNTRACK)
mc = NULL; /* will find mc in mt_cursors */
for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
for (; mc; mc=mc->mc_next) {
if (!(mc->mc_flags & C_INITIALIZED))
continue;
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;
}
}
if (i == 0)
break;
}
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 ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
break;
if ((dp->mp_flags & Mask) == pflags && level <= 1)
dp->mp_flags ^= P_KEEP;
}
}
}
return rc;
}
static int mdb_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 #mdb_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 #mdb_page_touch(). Such references are
* handled by #mdb_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
mdb_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 int 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 > MAIN_DBI)
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 = mdb_midl_alloc(MDB_IDL_UM_MAX);
if (!txn->mt_spill_pgs)
return ENOMEM;
} else {
/* purge deleted slots */
MDB_IDL sl = txn->mt_spill_pgs;
unsigned int 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 */
if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
goto done;
/* 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 = mdb_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;
}
if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
goto done;
need--;
}
mdb_midl_sort(txn->mt_spill_pgs);
/* Flush the spilled part of dirty list */
if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
goto done;
/* Reset any dirty pages we kept that page_flush didn't see */
rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
done:
txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
return rc;
}
/** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
static txnid_t
mdb_find_oldest(MDB_txn *txn)
{
int i;
txnid_t mr, oldest = txn->mt_txnid - 1;
if (txn->mt_env->me_txns) {
MDB_reader *r = txn->mt_env->me_txns->mti_readers;
for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
if (r[i].mr_pid) {
mr = r[i].mr_txnid;
if (oldest > mr)
oldest = mr;
}
}
}
return oldest;
}
/** Add a page to the txn's dirty list */
static void
mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
{
MDB_ID2 mid;
int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
if (txn->mt_env->me_flags & MDB_WRITEMAP) {
insert = mdb_mid2l_append;
} else {
insert = mdb_mid2l_insert;
}
mid.mid = mp->mp_pgno;
mid.mptr = mp;
rc = insert(txn->mt_u.dirty_list, &mid);
mdb_tassert(txn, rc == 0);
txn->mt_dirty_room--;
}
/** Allocate page numbers and memory for writing. Maintain me_pglast,
* me_pghead and mt_next_pgno.
*
* 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.
*/
static int
mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
{
#ifdef MDB_PARANOID /* Seems like we can ignore this now */
/* Get at most <Max_retries> more freeDB records once me_pghead
* has enough pages. If not enough, use new pages from the map.
* If <Paranoid> and mc is updating the freeDB, only get new
* records if me_pghead is empty. Then the freelist cannot play
* catch-up with itself by growing while trying to save it.
*/
enum { Paranoid = 1, Max_retries = 500 };
#else
enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
#endif
int rc, retry = num * 60;
MDB_txn *txn = mc->mc_txn;
MDB_env *env = txn->mt_env;
pgno_t pgno, *mop = env->me_pghead;
unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
MDB_page *np;
txnid_t oldest = 0, last;
MDB_cursor_op op;
MDB_cursor m2;
int found_old = 0;
/* If there are any loose pages, just use them */
if (num == 1 && txn->mt_loose_pgs) {
np = txn->mt_loose_pgs;
txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
txn->mt_loose_count--;
DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
np->mp_pgno));
*mp = np;
return MDB_SUCCESS;
}
*mp = NULL;
/* If our dirty list is already full, we can't do anything */
if (txn->mt_dirty_room == 0) {
rc = MDB_TXN_FULL;
goto fail;
}
for (op = MDB_FIRST;; op = 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 (mop_len > n2) {
i = mop_len;
do {
pgno = mop[i];
if (mop[i-n2] == pgno+n2)
goto search_done;
} while (--i > n2);
if (--retry < 0)
break;
}
if (op == MDB_FIRST) { /* 1st iteration */
/* Prepare to fetch more and coalesce */
last = env->me_pglast;
oldest = env->me_pgoldest;
mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
if (last) {
op = MDB_SET_RANGE;
key.mv_data = &last; /* will look up last+1 */
key.mv_size = sizeof(last);
}
if (Paranoid && mc->mc_dbi == FREE_DBI)
retry = -1;
}
if (Paranoid && retry < 0 && mop_len)
break;
last++;
/* Do not fetch more if the record will be too recent */
if (oldest <= last) {
if (!found_old) {
oldest = mdb_find_oldest(txn);
env->me_pgoldest = oldest;
found_old = 1;
}
if (oldest <= last)
break;
}
rc = mdb_cursor_get(&m2, &key, NULL, op);
if (rc) {
if (rc == MDB_NOTFOUND)
break;
goto fail;
}
last = *(txnid_t*)key.mv_data;
if (oldest <= last) {
if (!found_old) {
oldest = mdb_find_oldest(txn);
env->me_pgoldest = oldest;
found_old = 1;
}
if (oldest <= last)
break;
}
np = m2.mc_pg[m2.mc_top];
leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
return rc;
idl = (MDB_ID *) data.mv_data;
i = idl[0];
if (!mop) {
if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
rc = ENOMEM;
goto fail;
}
} else {
if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
goto fail;
mop = env->me_pghead;
}
env->me_pglast = last;
#if (MDB_DEBUG) > 1
DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
last, txn->mt_dbs[FREE_DBI].md_root, i));
for (j = i; j; j--)
DPRINTF(("IDL %"Z"u", idl[j]));
#endif
/* Merge in descending sorted order */
mdb_midl_xmerge(mop, idl);
mop_len = mop[0];
}
/* Use new pages from the map when nothing suitable in the freeDB */
i = 0;
pgno = txn->mt_next_pgno;
if (pgno + num >= env->me_maxpg) {
DPUTS("DB size maxed out");
rc = MDB_MAP_FULL;
goto fail;
}
search_done:
if (env->me_flags & MDB_WRITEMAP) {
np = (MDB_page *)(env->me_map + env->me_psize * pgno);
} else {
if (!(np = mdb_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;
}
np->mp_pgno = pgno;
mdb_page_dirty(txn, np);
*mp = np;
return MDB_SUCCESS;
fail:
txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
/** 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
mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int 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
mdb_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 = mdb_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 = mdb_page_malloc(txn, num);
if (!np)
return ENOMEM;
if (num > 1)
memcpy(np, mp, num * env->me_psize);
else
mdb_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
*/
mdb_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.
* @param[in] mc cursor pointing to the page to be touched
* @return 0 on success, non-zero on failure.
*/
static int
mdb_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 = mdb_page_unspill(txn, mp, &np);
if (rc)
goto fail;
if (np)
goto done;
}
if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
(rc = mdb_page_alloc(mc, 1, &np)))
goto fail;
pgno = np->mp_pgno;
DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
mp->mp_pgno, pgno));
mdb_cassert(mc, mp->mp_pgno != pgno);
mdb_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 = mdb_mid2l_search(dl, pgno);
if (x <= dl[0].mid && dl[x].mid == pgno) {
if (mp != dl[x].mptr) { /* bad cursor? */
mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
txn->mt_flags |= MDB_TXN_ERROR;
return MDB_CORRUPTED;
}
return 0;
}
}
mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
/* No - copy it */
np = mdb_page_malloc(txn, 1);
if (!np)
return ENOMEM;
mid.mid = pgno;
mid.mptr = np;
rc = mdb_mid2l_insert(dl, &mid);
mdb_cassert(mc, rc == 0);
} else {
return 0;
}
mdb_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_pg[mc->mc_top] == mp) {
m2->mc_pg[mc->mc_top] = np;
if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
IS_LEAF(np) &&
m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
{
MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
if (!(leaf->mn_flags & F_SUBDATA))
m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
}
}
}
}
return 0;
fail:
txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
int
mdb_env_sync(MDB_env *env, int force)
{
int rc = 0;
if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
if (env->me_flags & MDB_WRITEMAP) {
int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
? MS_ASYNC : MS_SYNC;
if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
rc = ErrCode();
#ifdef _WIN32
else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
rc = ErrCode();
#endif
} else {
if (MDB_FDATASYNC(env->me_fd))
rc = ErrCode();
}
}
return rc;
}
/** Back up parent txn's cursors, then grab the originals for tracking */
static int
mdb_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 (!bk)
return ENOMEM;
*bk = *mc;
mc->mc_backup = bk;
mc->mc_db = &dst->mt_dbs[i];
/* Kill pointers into src - and dst to reduce abuse: The
* user may not use mc until dst ends. Otherwise we'd...
*/
mc->mc_txn = NULL; /* ...set this to dst */
mc->mc_dbflag = NULL; /* ...and &dst->mt_dbflags[i] */
if ((mx = mc->mc_xcursor) != NULL) {
*(MDB_xcursor *)(bk+1) = *mx;
mx->mx_cursor.mc_txn = NULL; /* ...and 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
mdb_cursors_close(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) {
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);
}
mc = bk;
}
/* Only malloced cursors are permanently tracked. */
free(mc);
}
cursors[i] = NULL;
}
}
#if !(MDB_DEBUG)
#define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn)
#endif
static void
mdb_txn_reset0(MDB_txn *txn, const char *act);
#if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
enum Pidlock_op {
Pidset, Pidcheck
};
#else
enum Pidlock_op {
Pidset = F_SETLK, Pidcheck = F_GETLK
};
#endif
/** 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).
*
* On Windows Pidset is a no-op, we merely check for the existence
* of the process with the given pid. On POSIX we use a single byte
* lock on the lockfile, set at an offset equal to the pid.
*/
static int
mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
{
#if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
int ret = 0;
HANDLE h;
if (op == Pidcheck) {
h = OpenProcess(env->me_pidquery, FALSE, pid);
/* No documented "no such process" code, but other program use this: */
if (!h)
return ErrCode() != ERROR_INVALID_PARAMETER;
/* A process exists until all handles to it close. Has it exited? */
ret = WaitForSingleObject(h, 0) != 0;
CloseHandle(h);
}
return ret;
#else
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 = ErrCode()) == EINTR) {
continue;
}
return rc;
}
#endif
}
/** Common code for #mdb_txn_begin() and #mdb_txn_renew().
* @param[in] txn the transaction handle to initialize
* @return 0 on success, non-zero on failure.
*/
static int
mdb_txn_renew0(MDB_txn *txn)
{
MDB_env *env = txn->mt_env;
MDB_txninfo *ti = env->me_txns;
MDB_meta *meta;
unsigned int i, nr;
uint16_t x;
int rc, new_notls = 0;
/* Setup db info */
txn->mt_numdbs = env->me_numdbs;
txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
if (txn->mt_flags & MDB_TXN_RDONLY) {
if (!ti) {
meta = env->me_metas[ mdb_env_pick_meta(env) ];
txn->mt_txnid = meta->mm_txnid;
txn->mt_u.reader = NULL;
} else {
MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
pthread_getspecific(env->me_txkey);
if (r) {
if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
return MDB_BAD_RSLOT;
} else {
MDB_PID_T pid = env->me_pid;
MDB_THR_T tid = pthread_self();
if (!env->me_live_reader) {
rc = mdb_reader_pid(env, Pidset, pid);
if (rc)
return rc;
env->me_live_reader = 1;
}
LOCK_MUTEX_R(env);
nr = ti->mti_numreaders;
for (i=0; i<nr; i++)
if (ti->mti_readers[i].mr_pid == 0)
break;
if (i == env->me_maxreaders) {
UNLOCK_MUTEX_R(env);
return MDB_READERS_FULL;
}
ti->mti_readers[i].mr_pid = pid;
ti->mti_readers[i].mr_tid = tid;
if (i == nr)
ti->mti_numreaders = ++nr;
/* Save numreaders for un-mutexed mdb_env_close() */
env->me_numreaders = nr;
UNLOCK_MUTEX_R(env);
r = &ti->mti_readers[i];
new_notls = (env->me_flags & MDB_NOTLS);
if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
r->mr_pid = 0;
return rc;
}
}
txn->mt_txnid = r->mr_txnid = ti->mti_txnid;
txn->mt_u.reader = r;
meta = env->me_metas[txn->mt_txnid & 1];
}
} else {
if (ti) {
LOCK_MUTEX_W(env);
txn->mt_txnid = ti->mti_txnid;
meta = env->me_metas[txn->mt_txnid & 1];
} else {
meta = env->me_metas[ mdb_env_pick_meta(env) ];
txn->mt_txnid = meta->mm_txnid;
}
txn->mt_txnid++;
#if MDB_DEBUG
if (txn->mt_txnid == mdb_debug_start)
mdb_debug = 1;
#endif
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;
env->me_txn = txn;
memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
}
/* Copy the DB info and flags */
memcpy(txn->mt_dbs, meta->mm_dbs, 2 * sizeof(MDB_db));
/* Moved to here to avoid a data race in read TXNs */
txn->mt_next_pgno = meta->mm_last_pg+1;
for (i=2; i<txn->mt_numdbs; i++) {
x = env->me_dbflags[i];
txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0;
}
txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID;
if (env->me_maxpg < txn->mt_next_pgno) {
mdb_txn_reset0(txn, "renew0-mapfail");
if (new_notls) {
txn->mt_u.reader->mr_pid = 0;
txn->mt_u.reader = NULL;
}
return MDB_MAP_RESIZED;
}
return MDB_SUCCESS;
}
int
mdb_txn_renew(MDB_txn *txn)
{
int rc;
if (!txn || txn->mt_dbxs) /* A reset txn has mt_dbxs==NULL */
return EINVAL;
if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
DPUTS("environment had fatal error, must shutdown!");
return MDB_PANIC;
}
rc = mdb_txn_renew0(txn);
if (rc == MDB_SUCCESS) {
DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
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
mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
{
MDB_txn *txn;
MDB_ntxn *ntxn;
int rc, size, tsize = sizeof(MDB_txn);
if (env->me_flags & MDB_FATAL_ERROR) {
DPUTS("environment had fatal error, must shutdown!");
return MDB_PANIC;
}
if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
return EACCES;
if (parent) {
/* Nested transactions: Max 1 child, write txns only, no writemap */
if (parent->mt_child ||
(flags & MDB_RDONLY) ||
(parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) ||
(env->me_flags & MDB_WRITEMAP))
{
return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
}
tsize = sizeof(MDB_ntxn);
}
size = tsize + env->me_maxdbs * (sizeof(MDB_db)+1);
if (!(flags & MDB_RDONLY)) {
if (!parent) {
txn = env->me_txn0;
txn->mt_flags = 0;
goto ok;
}
size += env->me_maxdbs * sizeof(MDB_cursor *);
/* child txns use parent's dbiseqs */
if (!parent)
size += env->me_maxdbs * sizeof(unsigned int);
}
if ((txn = calloc(1, size)) == NULL) {
DPRINTF(("calloc: %s", strerror(errno)));
return ENOMEM;
}
txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
if (flags & MDB_RDONLY) {
txn->mt_flags |= MDB_TXN_RDONLY;
txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
txn->mt_dbiseqs = env->me_dbiseqs;
} else {
txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
if (parent) {
txn->mt_dbiseqs = parent->mt_dbiseqs;
txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
} else {
txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
}
}
txn->mt_env = env;
ok:
if (parent) {
unsigned int i;
txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
if (!txn->mt_u.dirty_list ||
!(txn->mt_free_pgs = mdb_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_child = txn;
txn->mt_parent = parent;
txn->mt_numdbs = parent->mt_numdbs;
txn->mt_flags = parent->mt_flags;
txn->mt_dbxs = parent->mt_dbxs;
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 = mdb_midl_alloc(env->me_pghead[0]);
if (env->me_pghead)
memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
else
rc = ENOMEM;
}
if (!rc)
rc = mdb_cursor_shadow(parent, txn);
if (rc)
mdb_txn_reset0(txn, "beginchild-fail");
} else {
rc = mdb_txn_renew0(txn);
}
if (rc) {
if (txn != env->me_txn0)
free(txn);
} else {
*ret = txn;
DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
(void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
}
return rc;
}
MDB_env *
mdb_txn_env(MDB_txn *txn)
{
if(!txn) return NULL;
return txn->mt_env;
}
/** Export or close DBI handles opened in this txn. */
static void
mdb_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 >= 2;) {
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;
}
/** Common code for #mdb_txn_reset() and #mdb_txn_abort().
* May be called twice for readonly txns: First reset it, then abort.
* @param[in] txn the transaction handle to reset
* @param[in] act why the transaction is being reset
*/
static void
mdb_txn_reset0(MDB_txn *txn, const char *act)
{
MDB_env *env = txn->mt_env;
/* Close any DBI handles opened in this txn */
mdb_dbis_update(txn, 0);
DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
act, 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) {
txn->mt_u.reader->mr_txnid = (txnid_t)-1;
if (!(env->me_flags & MDB_NOTLS))
txn->mt_u.reader = NULL; /* txn does not own reader */
}
txn->mt_numdbs = 0; /* close nothing if called again */
txn->mt_dbxs = NULL; /* mark txn as reset */
} else {
mdb_cursors_close(txn, 0);
if (!(env->me_flags & MDB_WRITEMAP)) {
mdb_dlist_free(txn);
}
mdb_midl_free(env->me_pghead);
if (txn->mt_parent) {
txn->mt_parent->mt_child = NULL;
env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
mdb_midl_free(txn->mt_free_pgs);
mdb_midl_free(txn->mt_spill_pgs);
free(txn->mt_u.dirty_list);
return;
}
if (mdb_midl_shrink(&txn->mt_free_pgs))
env->me_free_pgs = txn->mt_free_pgs;
env->me_pghead = NULL;
env->me_pglast = 0;
env->me_txn = NULL;
/* The writer mutex was locked in mdb_txn_begin. */
if (env->me_txns)
UNLOCK_MUTEX_W(env);
}
}
void
mdb_txn_reset(MDB_txn *txn)
{
if (txn == NULL)
return;
/* This call is only valid for read-only txns */
if (!(txn->mt_flags & MDB_TXN_RDONLY))
return;
mdb_txn_reset0(txn, "reset");
}
void
mdb_txn_abort(MDB_txn *txn)
{
if (txn == NULL)
return;
if (txn->mt_child)
mdb_txn_abort(txn->mt_child);
mdb_txn_reset0(txn, "abort");
/* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader)
txn->mt_u.reader->mr_pid = 0;
if (txn != txn->mt_env->me_txn0)
free(txn);
}
/** Save the freelist as of this transaction to the freeDB.
* This changes the freelist. Keep trying until it stabilizes.
*/
static int
mdb_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;
mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
if (env->me_pghead) {
/* Make sure first page of freeDB is touched and on freelist */
rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
if (rc && rc != MDB_NOTFOUND)
return rc;
}
if (!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 ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
return rc;
for (; mp; mp = NEXT_LOOSE_PAGE(mp))
mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
txn->mt_loose_pgs = NULL;
txn->mt_loose_count = 0;
}
/* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
? SSIZE_MAX : maxfree_1pg;
for (;;) {
/* Come back here after each Put() in case freelist changed */
MDB_val key, data;
pgno_t *pgs;
ssize_t j;
/* 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 = mdb_cursor_first(&mc, &key, NULL);
if (rc)
return rc;
pglast = head_id = *(txnid_t *)key.mv_data;
total_room = head_room = 0;
mdb_tassert(txn, pglast <= env->me_pglast);
rc = mdb_cursor_del(&mc, 0);
if (rc)
return rc;
}
/* Save the IDL of pages freed by this txn, to a single record */
if (freecnt < txn->mt_free_pgs[0]) {
if (!freecnt) {
/* Make sure last page of freeDB is touched and on freelist */
rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
if (rc && rc != MDB_NOTFOUND)
return rc;
}
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 = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
if (rc)
return rc;
/* Retry if mt_free_pgs[] grew during the Put() */
free_pgs = txn->mt_free_pgs;
} while (freecnt < free_pgs[0]);
mdb_midl_sort(free_pgs);
memcpy(data.mv_data, free_pgs, data.mv_size);
#if (MDB_DEBUG) > 1
{
unsigned int i = free_pgs[0];
DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
for (; i; i--)
DPRINTF(("IDL %"Z"u", free_pgs[i]));
}
#endif
continue;
}
mop = env->me_pghead;
mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
/* 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--;
head_room = 0;
}
/* (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;
}
key.mv_size = sizeof(head_id);
key.mv_data = &head_id;
data.mv_size = (head_room + 1) * sizeof(pgno_t);
rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
if (rc)
return rc;
/* 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;
}
/* 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 = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
return rc;
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;
mdb_midl_sort(loose);
mdb_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;
rc = mdb_cursor_first(&mc, &key, &data);
for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
txnid_t id = *(txnid_t *)key.mv_data;
ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
MDB_ID save;
mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
key.mv_data = &id;
if (len > mop_len) {
len = mop_len;
data.mv_size = (len + 1) * sizeof(MDB_ID);
}
data.mv_data = mop -= len;
save = mop[0];
mop[0] = len;
rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
mop[0] = save;
if (rc || !(mop_len -= len))
break;
}
}
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
mdb_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;
#ifdef _WIN32
OVERLAPPED ov;
#else
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;
#endif
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;
}
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;
}
#ifdef _WIN32
else break;
/* Windows actually supports scatter/gather I/O, but only on
* unbuffered file handles. Since we're relying on the OS page
* cache for all our data, that's self-defeating. So we just
* write pages one at a time. We use the ov structure to set
* the write offset, to at least save the overhead of a Seek
* system call.
*/
DPRINTF(("committing page %"Z"u", pgno));
memset(&ov, 0, sizeof(ov));
ov.Offset = pos & 0xffffffff;
ov.OffsetHigh = pos >> 16 >> 16;
if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
rc = ErrCode();
DPRINTF(("WriteFile: %d", rc));
return rc;
}
#else
/* 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) {
/* Write previous page(s) */
#ifdef MDB_USE_PWRITEV
wres = pwritev(env->me_fd, iov, n, wpos);
#else
if (n == 1) {
wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
} else {
if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
rc = ErrCode();
DPRINTF(("lseek: %s", strerror(rc)));
return rc;
}
wres = writev(env->me_fd, iov, n);
}
#endif
if (wres != wsize) {
if (wres < 0) {
rc = ErrCode();
DPRINTF(("Write error: %s", strerror(rc)));
} else {
rc = EIO; /* TODO: Use which error code? */
DPUTS("short write, filesystem full?");
}
return rc;
}
n = 0;
}
if (i > pagecount)
break;
wpos = pos;
wsize = 0;
}
DPRINTF(("committing page %"Z"u", pgno));
next_pos = pos + size;
iov[n].iov_len = size;
iov[n].iov_base = (char *)dp;
wsize += size;
n++;
#endif /* _WIN32 */
}
/* MIPS has cache coherency issues, this is a no-op everywhere else
* Note: for any size >= on-chip cache size, entire on-chip cache is
* flushed.
*/
CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
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;
}
mdb_dpage_free(env, dp);
}
done:
i--;
txn->mt_dirty_room += i - j;
dl[0].mid = j;
return MDB_SUCCESS;
}
int
mdb_txn_commit(MDB_txn *txn)
{
int rc;
unsigned int i;
MDB_env *env;
if (txn == NULL || txn->mt_env == NULL)
return EINVAL;
if (txn->mt_child) {
rc = mdb_txn_commit(txn->mt_child);
txn->mt_child = NULL;
if (rc)
goto fail;
}
env = txn->mt_env;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
mdb_dbis_update(txn, 1);
txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
mdb_txn_abort(txn);
return MDB_SUCCESS;
}
if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
DPUTS("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 free list to parent's */
rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
if (rc)
goto fail;
mdb_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 */
mdb_cursors_close(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[0] = txn->mt_dbflags[0];
parent->mt_dbflags[1] = txn->mt_dbflags[1];
for (i=2; 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;
}
/* 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 = mdb_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);
}
mdb_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 = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
if (rc)
parent->mt_flags |= MDB_TXN_ERROR;
mdb_midl_free(txn->mt_spill_pgs);
mdb_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;
mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
free(txn);
return rc;
}
if (txn != env->me_txn) {
DPUTS("attempt to commit unknown transaction");
rc = EINVAL;
goto fail;
}
mdb_cursors_close(txn, 0);
if (!txn->mt_u.dirty_list[0].mid &&
!(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
goto done;
DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
/* Update DB root pointers */
if (txn->mt_numdbs > 2) {
MDB_cursor mc;
MDB_dbi i;
MDB_val data;
data.mv_size = sizeof(MDB_db);
mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
for (i = 2; i < txn->mt_numdbs; i++) {
if (txn->mt_dbflags[i] & DB_DIRTY) {
if (TXN_DBI_CHANGED(txn, i)) {
rc = MDB_BAD_DBI;
goto fail;
}
data.mv_data = &txn->mt_dbs[i];
rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
if (rc)
goto fail;
}
}
}
rc = mdb_freelist_save(txn);
if (rc)
goto fail;
mdb_midl_free(env->me_pghead);
env->me_pghead = NULL;
if (mdb_midl_shrink(&txn->mt_free_pgs))
env->me_free_pgs = txn->mt_free_pgs;
#if (MDB_DEBUG) > 2
mdb_audit(txn);
#endif
if ((rc = mdb_page_flush(txn, 0)) ||
(rc = mdb_env_sync(env, 0)) ||
(rc = mdb_env_write_meta(txn)))
goto fail;
/* Free P_LOOSE pages left behind in dirty_list */
if (!(env->me_flags & MDB_WRITEMAP))
mdb_dlist_free(txn);
done:
env->me_pglast = 0;
env->me_txn = NULL;
mdb_dbis_update(txn, 1);
if (env->me_txns)
UNLOCK_MUTEX_W(env);
if (txn != env->me_txn0)
free(txn);
return MDB_SUCCESS;
fail:
mdb_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 ESECT
mdb_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.
*/
for (i=off=0; i<2; i++, off = meta->mm_psize) {
#ifdef _WIN32
DWORD len;
OVERLAPPED ov;
memset(&ov, 0, sizeof(ov));
ov.Offset = off;
rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
rc = 0;
#else
rc = pread(env->me_fd, &pbuf, Size, off);
#endif
if (rc != Size) {
if (rc == 0 && off == 0)
return ENOENT;
rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
DPRINTF(("read: %s", mdb_strerror(rc)));
return rc;
}
p = (MDB_page *)&pbuf;
if (!F_ISSET(p->mp_flags, P_META)) {
DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
return MDB_INVALID;
}
m = METADATA(p);
if (m->mm_magic != MDB_MAGIC) {
DPUTS("meta has invalid magic");
return MDB_INVALID;
}
if (m->mm_version != MDB_DATA_VERSION) {
DPRINTF(("database is version %u, expected version %u",
m->mm_version, MDB_DATA_VERSION));
return MDB_VERSION_MISMATCH;
}
if (off == 0 || m->mm_txnid > meta->mm_txnid)
*meta = *m;
}
return 0;
}
static void ESECT
mdb_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 = 1;
meta->mm_flags = env->me_flags & 0xffff;
meta->mm_flags |= MDB_INTEGERKEY;
meta->mm_dbs[0].md_root = P_INVALID;
meta->mm_dbs[1].md_root = P_INVALID;
}
/** Write the environment parameters of a freshly created DB environment.
* @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 ESECT
mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
{
MDB_page *p, *q;
int rc;
unsigned int psize;
#ifdef _WIN32
DWORD len;
OVERLAPPED ov;
memset(&ov, 0, sizeof(ov));
#define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
ov.Offset = pos; \
rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
#else
int len;
#define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
len = pwrite(fd, ptr, size, pos); \
rc = (len >= 0); } while(0)
#endif
DPUTS("writing new meta page");
psize = env->me_psize;
mdb_env_init_meta0(env, meta);
p = calloc(2, psize);
p->mp_pgno = 0;
p->mp_flags = P_META;
*(MDB_meta *)METADATA(p) = *meta;
q = (MDB_page *)((char *)p + psize);
q->mp_pgno = 1;
q->mp_flags = P_META;
*(MDB_meta *)METADATA(q) = *meta;
DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0);
if (!rc)
rc = ErrCode();
else if ((unsigned) len == psize * 2)
rc = MDB_SUCCESS;
else
rc = ENOSPC;
free(p);
return rc;
}
/** Update the environment info to commit a transaction.
* @param[in] txn the transaction that's being committed
* @return 0 on success, non-zero on failure.
*/
static int
mdb_env_write_meta(MDB_txn *txn)
{
MDB_env *env;
MDB_meta meta, metab, *mp;
size_t mapsize;
off_t off;
int rc, len, toggle;
char *ptr;
HANDLE mfd;
#ifdef _WIN32
OVERLAPPED ov;
#else
int r2;
#endif
toggle = txn->mt_txnid & 1;
DPRINTF(("writing meta page %d for root page %"Z"u",
toggle, txn->mt_dbs[MAIN_DBI].md_root));
env = txn->mt_env;
mp = env->me_metas[toggle];
mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
/* Persist any increases of mapsize config */
if (mapsize < env->me_mapsize)
mapsize = env->me_mapsize;
if (env->me_flags & MDB_WRITEMAP) {
mp->mm_mapsize = mapsize;
mp->mm_dbs[0] = txn->mt_dbs[0];
mp->mm_dbs[1] = txn->mt_dbs[1];
mp->mm_last_pg = txn->mt_next_pgno - 1;
mp->mm_txnid = txn->mt_txnid;
if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
unsigned meta_size = env->me_psize;
rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
ptr = env->me_map;
if (toggle) {
#ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
if (meta_size < env->me_os_psize)
meta_size += meta_size;
else
#endif
ptr += meta_size;
}
if (MDB_MSYNC(ptr, meta_size, rc)) {
rc = ErrCode();
goto fail;
}
}
goto done;
}
metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
meta.mm_mapsize = mapsize;
meta.mm_dbs[0] = txn->mt_dbs[0];
meta.mm_dbs[1] = txn->mt_dbs[1];
meta.mm_last_pg = txn->mt_next_pgno - 1;
meta.mm_txnid = txn->mt_txnid;
off = offsetof(MDB_meta, mm_mapsize);
ptr = (char *)&meta + off;
len = sizeof(MDB_meta) - off;
if (toggle)
off += env->me_psize;
off += PAGEHDRSZ;
/* Write to the SYNC fd */
mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
env->me_fd : env->me_mfd;
#ifdef _WIN32
{
memset(&ov, 0, sizeof(ov));
ov.Offset = off;
if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
rc = -1;
}
#else
rc = pwrite(mfd, ptr, len, off);
#endif
if (rc != len) {
rc = rc < 0 ? ErrCode() : EIO;
DPUTS("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.
* Use the non-SYNC fd; we know it will fail anyway.
*/
meta.mm_last_pg = metab.mm_last_pg;
meta.mm_txnid = metab.mm_txnid;
#ifdef _WIN32
memset(&ov, 0, sizeof(ov));
ov.Offset = off;
WriteFile(env->me_fd, ptr, len, NULL, &ov);
#else
r2 = pwrite(env->me_fd, ptr, len, off);
(void)r2; /* Silence warnings. We don't care about pwrite's return value */
#endif
fail:
env->me_flags |= MDB_FATAL_ERROR;
return rc;
}
/* MIPS has cache coherency issues, this is a no-op everywhere else */
CACHEFLUSH(env->me_map + off, len, DCACHE);
done:
/* 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.
*/
if (env->me_txns)
env->me_txns->mti_txnid = txn->mt_txnid;
return MDB_SUCCESS;
}
/** Check both meta pages to see which one is newer.
* @param[in] env the environment handle
* @return meta toggle (0 or 1).
*/
static int
mdb_env_pick_meta(const MDB_env *env)
{
return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
}
int ESECT
mdb_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 = 2;
e->me_fd = INVALID_HANDLE_VALUE;
e->me_lfd = INVALID_HANDLE_VALUE;
e->me_mfd = INVALID_HANDLE_VALUE;
#ifdef MDB_USE_POSIX_SEM
e->me_rmutex = SEM_FAILED;
e->me_wmutex = SEM_FAILED;
#endif
e->me_pid = getpid();
GET_PAGESIZE(e->me_os_psize);
VGMEMP_CREATE(e,0,0);
*env = e;
return MDB_SUCCESS;
}
static int ESECT
mdb_env_map(MDB_env *env, void *addr)
{
MDB_page *p;
unsigned int flags = env->me_flags;
#ifdef _WIN32
int rc;
HANDLE mh;
LONG sizelo, sizehi;
size_t msize;
if (flags & MDB_RDONLY) {
/* Don't set explicit map size, use whatever exists */
msize = 0;
sizelo = 0;
sizehi = 0;
} else {
msize = env->me_mapsize;
sizelo = msize & 0xffffffff;
sizehi = msize >> 16 >> 16; /* only needed on Win64 */
/* Windows won't create mappings for zero length files.
* and won't map more than the file size.
* Just set the maxsize right now.
*/
if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
|| !SetEndOfFile(env->me_fd)
|| SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
return ErrCode();
}
mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
PAGE_READWRITE : PAGE_READONLY,
sizehi, sizelo, NULL);
if (!mh)
return ErrCode();
env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
FILE_MAP_WRITE : FILE_MAP_READ,
0, 0, msize, addr);
rc = env->me_map ? 0 : ErrCode();
CloseHandle(mh);
if (rc)
return rc;
#else
int prot = PROT_READ;
if (flags & MDB_WRITEMAP) {
prot |= PROT_WRITE;
if (ftruncate(env->me_fd, env->me_mapsize) < 0)
return ErrCode();
}
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 ErrCode();
}
if (flags & MDB_NORDAHEAD) {
/* Turn off readahead. It's harmful when the DB is larger than RAM. */
#ifdef MADV_RANDOM
madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
#else
#ifdef POSIX_MADV_RANDOM
posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
#endif /* POSIX_MADV_RANDOM */
#endif /* MADV_RANDOM */
}
#endif /* _WIN32 */
/* 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)
return EBUSY; /* TODO: Make a new MDB_* error code? */
p = (MDB_page *)env->me_map;
env->me_metas[0] = METADATA(p);
env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
return MDB_SUCCESS;
}
int ESECT
mdb_env_set_mapsize(MDB_env *env, size_t size)
{
/* If env is already open, caller is responsible for making
* sure there are no active txns.
*/
if (env->me_map) {
int rc;
void *old;
if (env->me_txn)
return EINVAL;
if (!size)
size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
else if (size < env->me_mapsize) {
/* If the configured size is smaller, make sure it's
* still big enough. Silently round up to minimum if not.
*/
size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize;
if (size < minsize)
size = minsize;
}
munmap(env->me_map, env->me_mapsize);
env->me_mapsize = size;
old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
rc = mdb_env_map(env, old);
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 ESECT
mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
{
if (env->me_map)
return EINVAL;
env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
return MDB_SUCCESS;
}
int ESECT
mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
{
if (env->me_map || readers < 1)
return EINVAL;
env->me_maxreaders = readers;
return MDB_SUCCESS;
}
int ESECT
mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
{
if (!env || !readers)
return EINVAL;
*readers = env->me_maxreaders;
return MDB_SUCCESS;
}
/** Further setup required for opening an LMDB environment
*/
static int ESECT
mdb_env_open2(MDB_env *env)
{
unsigned int flags = env->me_flags;
int i, newenv = 0, rc;
MDB_meta meta;
#ifdef _WIN32
/* See if we should use QueryLimited */
rc = GetVersion();
if ((rc & 0xff) > 5)
env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
else
env->me_pidquery = PROCESS_QUERY_INFORMATION;
#endif /* _WIN32 */
memset(&meta, 0, sizeof(meta));
if ((i = mdb_env_read_header(env, &meta)) != 0) {
if (i != ENOENT)
return i;
DPUTS("new mdbenv");
newenv = 1;
env->me_psize = env->me_os_psize;
if (env->me_psize > MAX_PAGESIZE)
env->me_psize = MAX_PAGESIZE;
} else {
env->me_psize = meta.mm_psize;
}
/* Was a mapsize configured? */
if (!env->me_mapsize) {
/* If this is a new environment, take the default,
* else use the size recorded in the existing env.
*/
env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
} else if (env->me_mapsize < meta.mm_mapsize) {
/* If the configured size is smaller, make sure it's
* still big enough. Silently round up to minimum if not.
*/
size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
if (env->me_mapsize < minsize)
env->me_mapsize = minsize;
}
rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
if (rc)
return rc;
if (newenv) {
if (flags & MDB_FIXEDMAP)
meta.mm_address = env->me_map;
i = mdb_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);
#if !(MDB_MAXKEYSIZE)
env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
#endif
env->me_maxpg = env->me_mapsize / env->me_psize;
#if MDB_DEBUG
{
int toggle = mdb_env_pick_meta(env);
MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
DPRINTF(("opened database version %u, pagesize %u",
env->me_metas[0]->mm_version, env->me_psize));
DPRINTF(("using meta page %d", toggle));
DPRINTF(("depth: %u", db->md_depth));
DPRINTF(("entries: %"Z"u", db->md_entries));
DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
DPRINTF(("root: %"Z"u", db->md_root));
}
#endif
return MDB_SUCCESS;
}
/** 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 slot in the reader lock table.
*/
static void
mdb_env_reader_dest(void *ptr)
{
MDB_reader *reader = ptr;
reader->mr_pid = 0;
}
#ifdef _WIN32
/** Junk for arranging thread-specific callbacks on Windows. This is
* necessarily platform and compiler-specific. Windows supports up
* to 1088 keys. Let's assume nobody opens more than 64 environments
* in a single process, for now. They can override this if needed.
*/
#ifndef MAX_TLS_KEYS
#define MAX_TLS_KEYS 64
#endif
static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
static int mdb_tls_nkeys;
static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
{
int i;
switch(reason) {
case DLL_PROCESS_ATTACH: break;
case DLL_THREAD_ATTACH: break;
case DLL_THREAD_DETACH:
for (i=0; i<mdb_tls_nkeys; i++) {
MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
if (r) {
mdb_env_reader_dest(r);
}
}
break;
case DLL_PROCESS_DETACH: break;
}
}
#ifdef __GNUC__
#ifdef _WIN64
const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
#else
PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
#endif
#else
#ifdef _WIN64
/* Force some symbol references.
* _tls_used forces the linker to create the TLS directory if not already done
* mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
*/
#pragma comment(linker, "/INCLUDE:_tls_used")
#pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
#pragma const_seg(".CRT$XLB")
extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
#pragma const_seg()
#else /* WIN32 */
#pragma comment(linker, "/INCLUDE:__tls_used")
#pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
#pragma data_seg(".CRT$XLB")
PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
#pragma data_seg()
#endif /* WIN 32/64 */
#endif /* !__GNUC__ */
#endif
/** Downgrade the exclusive lock on the region back to shared */
static int ESECT
mdb_env_share_locks(MDB_env *env, int *excl)
{
int rc = 0, toggle = mdb_env_pick_meta(env);
env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
#ifdef _WIN32
{
OVERLAPPED ov;
/* First acquire a shared lock. The Unlock will
* then release the existing exclusive lock.
*/
memset(&ov, 0, sizeof(ov));
if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
rc = ErrCode();
} else {
UnlockFile(env->me_lfd, 0, 0, 1, 0);
*excl = 0;
}
}
#else
{
struct flock lock_info;
/* 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 = ErrCode()) == EINTR) ;
*excl = rc ? -1 : 0; /* error may mean we lost the lock */
}
#endif
return rc;
}
/** Try to get exlusive lock, otherwise shared.
* Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
*/
static int ESECT
mdb_env_excl_lock(MDB_env *env, int *excl)
{
int rc = 0;
#ifdef _WIN32
if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
*excl = 1;
} else {
OVERLAPPED ov;
memset(&ov, 0, sizeof(ov));
if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
*excl = 0;
} else {
rc = ErrCode();
}
}
#else
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 = ErrCode()) == EINTR) ;
if (!rc) {
*excl = 1;
} else
# ifdef MDB_USE_POSIX_SEM
if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
# endif
{
lock_info.l_type = F_RDLCK;
while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
(rc = ErrCode()) == EINTR) ;
if (rc == 0)
*excl = 0;
}
#endif
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 <Landon Curt Noll> /\oo/\
* http://www.isthe.com/chongo/
*
* Share and Enjoy! :-)
*/
typedef unsigned long long mdb_hash_t;
#define MDB_HASH_INIT ((mdb_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 mdb_hash_t
mdb_hash_val(MDB_val *val, mdb_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 ^= (mdb_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 mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
static void
mdb_pack85(unsigned long l, char *out)
{
int i;
for (i=0; i<5; i++) {
*out++ = mdb_a85[l % 85];
l /= 85;
}
}
static void
mdb_hash_enc(MDB_val *val, char *encbuf)
{
mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
mdb_pack85(h, encbuf);
mdb_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[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive
* @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 ESECT
mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
{
#ifdef _WIN32
# define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
#else
# define MDB_ERRCODE_ROFS EROFS
#ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
# define MDB_CLOEXEC O_CLOEXEC
#else
int fdflags;
# define MDB_CLOEXEC 0
#endif
#endif
int rc;
off_t size, rsize;
#ifdef _WIN32
env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
FILE_ATTRIBUTE_NORMAL, NULL);
#else
env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
#endif
if (env->me_lfd == INVALID_HANDLE_VALUE) {
rc = ErrCode();
if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
return MDB_SUCCESS;
}
goto fail_errno;
}
#if ! ((MDB_CLOEXEC) || defined(_WIN32))
/* Lose record locks when exec*() */
if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
fcntl(env->me_lfd, F_SETFD, fdflags);
#endif
if (!(env->me_flags & MDB_NOTLS)) {
rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
if (rc)
goto fail;
env->me_flags |= MDB_ENV_TXKEY;
#ifdef _WIN32
/* Windows TLS callbacks need help finding their TLS info. */
if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
rc = MDB_TLS_FULL;
goto fail;
}
mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
#endif
}
/* Try to get exclusive lock. If we succeed, then
* nobody is using the lock region and we should initialize it.
*/
if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
#ifdef _WIN32
size = GetFileSize(env->me_lfd, NULL);
#else
size = lseek(env->me_lfd, 0, SEEK_END);
if (size == -1) goto fail_errno;
#endif
rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
if (size < rsize && *excl > 0) {
#ifdef _WIN32
if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
|| !SetEndOfFile(env->me_lfd))
goto fail_errno;
#else
if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
#endif
} else {
rsize = size;
size = rsize - sizeof(MDB_txninfo);
env->me_maxreaders = size/sizeof(MDB_reader) + 1;
}
{
#ifdef _WIN32
HANDLE mh;
mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
0, 0, NULL);
if (!mh) goto fail_errno;
env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
CloseHandle(mh);
if (!env->me_txns) goto fail_errno;
#else
void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
env->me_lfd, 0);
if (m == MAP_FAILED) goto fail_errno;
env->me_txns = m;
#endif
}
if (*excl > 0) {
#ifdef _WIN32
BY_HANDLE_FILE_INFORMATION stbuf;
struct {
DWORD volume;
DWORD nhigh;
DWORD nlow;
} idbuf;
MDB_val val;
char encbuf[11];
if (!mdb_sec_inited) {
InitializeSecurityDescriptor(&mdb_null_sd,
SECURITY_DESCRIPTOR_REVISION);
SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
mdb_all_sa.bInheritHandle = FALSE;
mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
mdb_sec_inited = 1;
}
if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
idbuf.volume = stbuf.dwVolumeSerialNumber;
idbuf.nhigh = stbuf.nFileIndexHigh;
idbuf.nlow = stbuf.nFileIndexLow;
val.mv_data = &idbuf;
val.mv_size = sizeof(idbuf);
mdb_hash_enc(&val, encbuf);
sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
if (!env->me_rmutex) goto fail_errno;
env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
if (!env->me_wmutex) goto fail_errno;
#elif defined(MDB_USE_POSIX_SEM)
struct stat stbuf;
struct {
dev_t dev;
ino_t ino;
} idbuf;
MDB_val val;
char encbuf[11];
#if defined(__NetBSD__)
#define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
#endif
if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
idbuf.dev = stbuf.st_dev;
idbuf.ino = stbuf.st_ino;
val.mv_data = &idbuf;
val.mv_size = sizeof(idbuf);
mdb_hash_enc(&val, encbuf);
#ifdef MDB_SHORT_SEMNAMES
encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
#endif
sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
/* Clean up after a previous run, if needed: Try to
* remove both semaphores before doing anything else.
*/
sem_unlink(env->me_txns->mti_rmname);
sem_unlink(env->me_txns->mti_wmname);
env->me_rmutex = sem_open(env->me_txns->mti_rmname,
O_CREAT|O_EXCL, mode, 1);
if (env->me_rmutex == SEM_FAILED) goto fail_errno;
env->me_wmutex = sem_open(env->me_txns->mti_wmname,
O_CREAT|O_EXCL, mode, 1);
if (env->me_wmutex == SEM_FAILED) goto fail_errno;
#else /* MDB_USE_POSIX_SEM */
pthread_mutexattr_t mattr;
if ((rc = pthread_mutexattr_init(&mattr))
|| (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
|| (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
|| (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
goto fail;
pthread_mutexattr_destroy(&mattr);
#endif /* _WIN32 || MDB_USE_POSIX_SEM */
env->me_txns->mti_magic = MDB_MAGIC;
env->me_txns->mti_format = MDB_LOCK_FORMAT;
env->me_txns->mti_txnid = 0;
env->me_txns->mti_numreaders = 0;
} else {
if (env->me_txns->mti_magic != MDB_MAGIC) {
DPUTS("lock region has invalid magic");
rc = MDB_INVALID;
goto fail;
}
if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
env->me_txns->mti_format, MDB_LOCK_FORMAT));
rc = MDB_VERSION_MISMATCH;
goto fail;
}
rc = ErrCode();
if (rc && rc != EACCES && rc != EAGAIN) {
goto fail;
}
#ifdef _WIN32
env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
if (!env->me_rmutex) goto fail_errno;
env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
if (!env->me_wmutex) goto fail_errno;
#elif defined(MDB_USE_POSIX_SEM)
env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
if (env->me_rmutex == SEM_FAILED) goto fail_errno;
env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
if (env->me_wmutex == SEM_FAILED) goto fail_errno;
#endif
}
return MDB_SUCCESS;
fail_errno:
rc = ErrCode();
fail:
return rc;
}
/** 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 mdb_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)
#define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| \
MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
#if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
# error "Persistent DB flags & env flags overlap, but both go in mm_flags"
#endif
int ESECT
mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
{
int oflags, rc, len, excl = -1;
char *lpath, *dpath;
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) {
/* silently ignore WRITEMAP when we're only getting read access */
flags &= ~MDB_WRITEMAP;
} else {
if (!((env->me_free_pgs = mdb_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 int));
if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
rc = ENOMEM;
goto leave;
}
/* For RDONLY, get lockfile after we know datafile exists */
if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
rc = mdb_env_setup_locks(env, lpath, mode, &excl);
if (rc)
goto leave;
}
#ifdef _WIN32
if (F_ISSET(flags, MDB_RDONLY)) {
oflags = GENERIC_READ;
len = OPEN_EXISTING;
} else {
oflags = GENERIC_READ|GENERIC_WRITE;
len = OPEN_ALWAYS;
}
mode = FILE_ATTRIBUTE_NORMAL;
env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL, len, mode, NULL);
#else
if (F_ISSET(flags, MDB_RDONLY))
oflags = O_RDONLY;
else
oflags = O_RDWR | O_CREAT;
env->me_fd = open(dpath, oflags, mode);
#endif
if (env->me_fd == INVALID_HANDLE_VALUE) {
rc = ErrCode();
goto leave;
}
if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
rc = mdb_env_setup_locks(env, lpath, mode, &excl);
if (rc)
goto leave;
}
if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
env->me_mfd = env->me_fd;
} else {
/* Synchronous fd for meta writes. Needed even with
* MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
*/
#ifdef _WIN32
len = OPEN_EXISTING;
env->me_mfd = CreateFile(dpath, oflags,
FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
mode | FILE_FLAG_WRITE_THROUGH, NULL);
#else
oflags &= ~O_CREAT;
env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
#endif
if (env->me_mfd == INVALID_HANDLE_VALUE) {
rc = ErrCode();
goto leave;
}
}
DPRINTF(("opened dbenv %p", (void *) env));
if (excl > 0) {
rc = mdb_env_share_locks(env, &excl);
if (rc)
goto leave;
}
if (!((flags & MDB_RDONLY) ||
(env->me_pbuf = calloc(1, env->me_psize))))
rc = ENOMEM;
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 int)+1);
txn = calloc(1, size);
if (txn) {
txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
txn->mt_env = env;
env->me_txn0 = txn;
} else {
rc = ENOMEM;
}
}
}
leave:
if (rc) {
mdb_env_close0(env, excl);
}
free(lpath);
return rc;
}
/** Destroy resources from mdb_env_open(), clear our readers & DBIs */
static void ESECT
mdb_env_close0(MDB_env *env, int excl)
{
int i;
if (!(env->me_flags & MDB_ENV_ACTIVE))
return;
/* Doing this here since me_dbxs may not exist during mdb_env_close */
for (i = env->me_maxdbs; --i > MAIN_DBI; )
free(env->me_dbxs[i].md_name.mv_data);
free(env->me_pbuf);
free(env->me_dbiseqs);
free(env->me_dbflags);
free(env->me_dbxs);
free(env->me_path);
free(env->me_dirty_list);
free(env->me_txn0);
mdb_midl_free(env->me_free_pgs);
if (env->me_flags & MDB_ENV_TXKEY) {
pthread_key_delete(env->me_txkey);
#ifdef _WIN32
/* Delete our key from the global list */
for (i=0; i<mdb_tls_nkeys; i++)
if (mdb_tls_keys[i] == env->me_txkey) {
mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
mdb_tls_nkeys--;
break;
}
#endif
}
if (env->me_map) {
munmap(env->me_map, env->me_mapsize);
}
if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
(void) close(env->me_mfd);
if (env->me_fd != INVALID_HANDLE_VALUE)
(void) close(env->me_fd);
if (env->me_txns) {
MDB_PID_T pid = env->me_pid;
/* Clearing readers is done in this function because
* me_txkey with its destructor must be disabled first.
*/
for (i = env->me_numreaders; --i >= 0; )
if (env->me_txns->mti_readers[i].mr_pid == pid)
env->me_txns->mti_readers[i].mr_pid = 0;
#ifdef _WIN32
if (env->me_rmutex) {
CloseHandle(env->me_rmutex);
if (env->me_wmutex) CloseHandle(env->me_wmutex);
}
/* Windows automatically destroys the mutexes when
* the last handle closes.
*/
#elif defined(MDB_USE_POSIX_SEM)
if (env->me_rmutex != SEM_FAILED) {
sem_close(env->me_rmutex);
if (env->me_wmutex != SEM_FAILED)
sem_close(env->me_wmutex);
/* If we have the filelock: If we are the
* only remaining user, clean up semaphores.
*/
if (excl == 0)
mdb_env_excl_lock(env, &excl);
if (excl > 0) {
sem_unlink(env->me_txns->mti_rmname);
sem_unlink(env->me_txns->mti_wmname);
}
}
#endif
munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
}
if (env->me_lfd != INVALID_HANDLE_VALUE) {
#ifdef _WIN32
if (excl >= 0) {
/* Unlock the lockfile. Windows would have unlocked it
* after closing anyway, but not necessarily at once.
*/
UnlockFile(env->me_lfd, 0, 0, 1, 0);
}
#endif
(void) close(env->me_lfd);
}
env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
}
void ESECT
mdb_env_close(MDB_env *env)
{
MDB_page *dp;
if (env == NULL)
return;
VGMEMP_DESTROY(env);
while ((dp = env->me_dpages) != NULL) {
VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
env->me_dpages = dp->mp_next;
free(dp);
}
mdb_env_close0(env, 0);
free(env);
}
/** Compare two items pointing at aligned size_t's */
static int
mdb_cmp_long(const MDB_val *a, const MDB_val *b)
{
return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
*(size_t *)a->mv_data > *(size_t *)b->mv_data;
}
/** Compare two items pointing at aligned unsigned int's */
static int
mdb_cmp_int(const MDB_val *a, const MDB_val *b)
{
return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
*(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
}
/** Compare two items pointing at unsigned ints of unknown alignment.
* Nodes and keys are guaranteed to be 2-byte aligned.
*/
static int
mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
{
#if BYTE_ORDER == LITTLE_ENDIAN
unsigned short *u, *c;
int x;
u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
do {
x = *--u - *--c;
} while(!x && u > (unsigned short *)a->mv_data);
return x;
#else
unsigned short *u, *c, *end;
int x;
end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
u = (unsigned short *)a->mv_data;
c = (unsigned short *)b->mv_data;
do {
x = *u++ - *c++;
} while(!x && u < end);
return x;
#endif
}
/** Compare two items pointing at size_t's of unknown alignment. */
#ifdef MISALIGNED_OK
# define mdb_cmp_clong mdb_cmp_long
#else
# define mdb_cmp_clong mdb_cmp_cint
#endif
/** Compare two items lexically */
static int
mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
{
int diff;
ssize_t len_diff;
unsigned int len;
len = a->mv_size;
len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
if (len_diff > 0) {
len = b->mv_size;
len_diff = 1;
}
diff = memcmp(a->mv_data, b->mv_data, len);
return diff ? diff : len_diff<0 ? -1 : len_diff;
}
/** Compare two items in reverse byte order */
static int
mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
{
const unsigned char *p1, *p2, *p1_lim;
ssize_t len_diff;
int diff;
p1_lim = (const unsigned char *)a->mv_data;
p1 = (const unsigned char *)a->mv_data + a->mv_size;
p2 = (const unsigned char *)b->mv_data + b->mv_size;
len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
if (len_diff > 0) {
p1_lim += len_diff;
len_diff = 1;
}
while (p1 > p1_lim) {
diff = *--p1 - *--p2;
if (diff)
return diff;
}
return len_diff<0 ? -1 : len_diff;
}
/** 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 *
mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
{
unsigned int 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);
DPRINTF(("searching %u keys in %s %spage %"Z"u",
nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
mdb_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 mdb_cmp_int.
*/
if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
cmp = mdb_cmp_long;
else
cmp = mdb_cmp_int;
}
if (IS_LEAF2(mp)) {
nodekey.mv_size = mc->mc_db->md_pad;
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);
DPRINTF(("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 MDB_DEBUG
if (IS_LEAF(mp))
DPRINTF(("found leaf index %u [%s], rc = %i",
i, DKEY(&nodekey), rc));
else
DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
i, DKEY(&nodekey), NODEPGNO(node), rc));
#endif
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 (!IS_LEAF2(mp))
node = NODEPTR(mp, i);
}
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 node;
}
#if 0
static void
mdb_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
mdb_cursor_pop(MDB_cursor *mc)
{
if (mc->mc_snum) {
#if MDB_DEBUG
MDB_page *top = mc->mc_pg[mc->mc_top];
#endif
mc->mc_snum--;
if (mc->mc_snum)
mc->mc_top--;
DPRINTF(("popped page %"Z"u off db %d cursor %p", top->mp_pgno,
DDBI(mc), (void *) mc));
}
}
/** Push a page onto the top of the cursor's stack. */
static int
mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
{
DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
DDBI(mc), (void *) mc));
if (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.
* @param[in] txn the transaction for this access.
* @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
mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
{
MDB_env *env = txn->mt_env;
MDB_page *p = NULL;
int level;
if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_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 = mdb_midl_search(tx2->mt_spill_pgs, pn);
if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
p = (MDB_page *)(env->me_map + env->me_psize * pgno);
goto done;
}
}
if (dl[0].mid) {
unsigned x = mdb_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 (pgno < txn->mt_next_pgno) {
level = 0;
p = (MDB_page *)(env->me_map + env->me_psize * pgno);
} else {
DPRINTF(("page %"Z"u not found", pgno));
txn->mt_flags |= MDB_TXN_ERROR;
return MDB_PAGE_NOTFOUND;
}
done:
*ret = p;
if (lvl)
*lvl = level;
return MDB_SUCCESS;
}
/** Finish #mdb_page_search() / #mdb_page_search_lowest().
* The cursor is at the root page, set up the rest of it.
*/
static int
mdb_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;
DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
mdb_cassert(mc, NUMKEYS(mp) > 1);
DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
i = 0;
if (flags & MDB_PS_LAST)
i = NUMKEYS(mp) - 1;
} else {
int exact;
node = mdb_node_search(mc, key, &exact);
if (node == NULL)
i = NUMKEYS(mp) - 1;
else {
i = mc->mc_ki[mc->mc_top];
if (!exact) {
mdb_cassert(mc, i > 0);
i--;
}
}
DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
}
mdb_cassert(mc, i < NUMKEYS(mp));
node = NODEPTR(mp, i);
if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
return rc;
mc->mc_ki[mc->mc_top] = i;
if ((rc = mdb_cursor_push(mc, mp)))
return rc;
if (flags & MDB_PS_MODIFY) {
if ((rc = mdb_page_touch(mc)) != 0)
return rc;
mp = mc->mc_pg[mc->mc_top];
}
}
if (!IS_LEAF(mp)) {
DPRINTF(("internal error, index points to a %02X page!?",
mp->mp_flags));
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
return MDB_CORRUPTED;
}
DPRINTF(("found leaf page %"Z"u 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 mdb_page_search_root(), because the callers
* are all in situations where the current page is known to
* be underfilled.
*/
static int
mdb_page_search_lowest(MDB_cursor *mc)
{
MDB_page *mp = mc->mc_pg[mc->mc_top];
MDB_node *node = NODEPTR(mp, 0);
int rc;
if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
return rc;
mc->mc_ki[mc->mc_top] = 0;
if ((rc = mdb_cursor_push(mc, mp)))
return rc;
return mdb_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 #mdb_cursor_first() and #mdb_cursor_last().
* If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
* @return 0 on success, non-zero on failure.
*/
static int
mdb_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 (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
DPUTS("transaction has failed, must abort");
return MDB_BAD_TXN;
} else {
/* Make sure we're using an up-to-date root */
if (*mc->mc_dbflag & DB_STALE) {
MDB_cursor mc2;
if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
return MDB_BAD_DBI;
mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
rc = mdb_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 = mdb_node_search(&mc2,
&mc->mc_dbx->md_name, &exact);
if (!exact)
return MDB_NOTFOUND;
rc = mdb_node_read(mc->mc_txn, 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 ((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 (root == P_INVALID) { /* Tree is empty. */
DPUTS("tree is empty");
return MDB_NOTFOUND;
}
}
mdb_cassert(mc, root > 1);
if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
return rc;
mc->mc_snum = 1;
mc->mc_top = 0;
DPRINTF(("db %d root page %"Z"u has flags 0x%X",
DDBI(mc), root, mc->mc_pg[0]->mp_flags));
if (flags & MDB_PS_MODIFY) {
if ((rc = mdb_page_touch(mc)))
return rc;
}
if (flags & MDB_PS_ROOTONLY)
return MDB_SUCCESS;
return mdb_page_search_root(mc, key, flags);
}
static int
mdb_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;
DPRINTF(("free ov page %"Z"u (%d)", 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 = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
{
unsigned i, j;
pgno_t *mop;
MDB_ID2 *dl, ix, iy;
rc = mdb_midl_need(&env->me_pghead, ovpages);
if (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 (x > 1) {
x--;
iy = dl[x];
dl[x] = ix;
} else {
mdb_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_CORRUPTED;
}
}
if (!(env->me_flags & MDB_WRITEMAP))
mdb_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 = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
if (rc)
return rc;
}
mc->mc_db->md_overflow_pages -= ovpages;
return 0;
}
/** Return the data associated with a given node.
* @param[in] txn The transaction 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 int
mdb_node_read(MDB_txn *txn, 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 ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
DPRINTF(("read overflow page %"Z"u failed", pgno));
return rc;
}
data->mv_data = METADATA(omp);
return MDB_SUCCESS;
}
int
mdb_get(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data)
{
MDB_cursor mc;
MDB_xcursor mx;
int exact = 0;
DKBUF;
DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
return MDB_BAD_TXN;
mdb_cursor_init(&mc, txn, dbi, &mx);
return mdb_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
mdb_cursor_sibling(MDB_cursor *mc, int move_right)
{
int rc;
MDB_node *indx;
MDB_page *mp;
if (mc->mc_snum < 2) {
return MDB_NOTFOUND; /* root has no siblings */
}
mdb_cursor_pop(mc);
DPRINTF(("parent page is page %"Z"u, 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)) {
DPRINTF(("no more keys left, moving to %s sibling",
move_right ? "right" : "left"));
if ((rc = mdb_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]--;
DPRINTF(("just moving to %s index key %u",
move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
}
mdb_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 ((rc = mdb_page_get(mc->mc_txn, 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;
}
mdb_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
mdb_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_EOF) {
return MDB_NOTFOUND;
}
mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
mp = mc->mc_pg[mc->mc_top];
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 = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
if (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;
}
}
DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
mdb_dbg_pgno(mp), (void *) mc));
if (mc->mc_flags & C_DEL)
goto skip;
if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
DPUTS("=====> move to next sibling page");
if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
mc->mc_flags |= C_EOF;
return rc;
}
mp = mc->mc_pg[mc->mc_top];
DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
} else
mc->mc_ki[mc->mc_top]++;
skip:
DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
if (IS_LEAF2(mp)) {
key->mv_size = mc->mc_db->md_pad;
key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
return MDB_SUCCESS;
}
mdb_cassert(mc, IS_LEAF(mp));
leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(mc, leaf);
}
if (data) {
if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
if (rc != MDB_SUCCESS)
return rc;
}
}
MDB_GET_KEY(leaf, key);
return MDB_SUCCESS;
}
/** Move the cursor to the previous data item. */
static int
mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
{
MDB_page *mp;
MDB_node *leaf;
int rc;
mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
mp = mc->mc_pg[mc->mc_top];
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_PREV || op == MDB_PREV_DUP) {
rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
if (op != MDB_PREV || rc != MDB_NOTFOUND) {
if (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;
}
}
}
DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
mdb_dbg_pgno(mp), (void *) mc));
if (mc->mc_ki[mc->mc_top] == 0) {
DPUTS("=====> move to prev sibling page");
if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
return rc;
}
mp = mc->mc_pg[mc->mc_top];
mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
} else
mc->mc_ki[mc->mc_top]--;
mc->mc_flags &= ~C_EOF;
DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
if (IS_LEAF2(mp)) {
key->mv_size = mc->mc_db->md_pad;
key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
return MDB_SUCCESS;
}
mdb_cassert(mc, IS_LEAF(mp));
leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(mc, leaf);
}
if (data) {
if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
if (rc != MDB_SUCCESS)
return rc;
}
}
MDB_GET_KEY(leaf, key);
return MDB_SUCCESS;
}
/** Set the cursor on a specific data item. */
static int
mdb_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 (key->mv_size == 0)
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_pad;
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 int i;
unsigned int 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;
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;
}
}
rc = mdb_page_search(mc, key, 0);
if (rc != MDB_SUCCESS)
return rc;
mp = mc->mc_pg[mc->mc_top];
mdb_cassert(mc, IS_LEAF(mp));
set2:
leaf = mdb_node_search(mc, key, exactp);
if (exactp != NULL && !*exactp) {
/* MDB_SET specified and not an exact match. */
return MDB_NOTFOUND;
}
if (leaf == NULL) {
DPUTS("===> inexact leaf not found, goto sibling");
if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
return rc; /* no entries matched */
mp = mc->mc_pg[mc->mc_top];
mdb_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_pad;
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)) {
mdb_xcursor_init1(mc, leaf);
}
if (data) {
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
rc = mdb_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 = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
if (rc != MDB_SUCCESS)
return rc;
}
} else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
MDB_val d2;
if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
return rc;
rc = mc->mc_dbx->md_dcmp(data, &d2);
if (rc) {
if (op == MDB_GET_BOTH || rc > 0)
return MDB_NOTFOUND;
rc = 0;
*data = d2;
}
} else {
if (mc->mc_xcursor)
mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
if ((rc = mdb_node_read(mc->mc_txn, 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);
DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
return rc;
}
/** Move the cursor to the first item in the database. */
static int
mdb_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 = mdb_page_search(mc, NULL, MDB_PS_FIRST);
if (rc != MDB_SUCCESS)
return rc;
}
mdb_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_pad;
key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
return MDB_SUCCESS;
}
if (data) {
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(mc, leaf);
rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
if (rc)
return rc;
} else {
if ((rc = mdb_node_read(mc->mc_txn, 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
mdb_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 (!(mc->mc_flags & C_EOF)) {
if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
if (rc != MDB_SUCCESS)
return rc;
}
mdb_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_pad;
key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
return MDB_SUCCESS;
}
if (data) {
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(mc, leaf);
rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
if (rc)
return rc;
} else {
if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
}
}
MDB_GET_KEY(leaf, key);
return MDB_SUCCESS;
}
int
mdb_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 (mc == NULL)
return EINVAL;
if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
return MDB_BAD_TXN;
switch (op) {
case MDB_GET_CURRENT:
if (!(mc->mc_flags & C_INITIALIZED)) {
rc = EINVAL;
} else {
MDB_page *mp = mc->mc_pg[mc->mc_top];
int nkeys = NUMKEYS(mp);
if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
mc->mc_ki[mc->mc_top] = nkeys;
rc = MDB_NOTFOUND;
break;
}
rc = MDB_SUCCESS;
if (IS_LEAF2(mp)) {
key->mv_size = mc->mc_db->md_pad;
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 (mc->mc_flags & C_DEL)
mdb_xcursor_init1(mc, leaf);
rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
} else {
rc = mdb_node_read(mc->mc_txn, leaf, data);
}
}
}
}
break;
case MDB_GET_BOTH:
case MDB_GET_BOTH_RANGE:
if (data == NULL) {
rc = EINVAL;
break;
}
if (mc->mc_xcursor == NULL) {
rc = MDB_INCOMPATIBLE;
break;
}
/* FALLTHRU */
case MDB_SET:
case MDB_SET_KEY:
case MDB_SET_RANGE:
if (key == NULL) {
rc = EINVAL;
} else {
rc = mdb_cursor_set(mc, key, data, op,
op == MDB_SET_RANGE ? NULL : &exact);
}
break;
case MDB_GET_MULTIPLE:
if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
rc = EINVAL;
break;
}
if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
rc = MDB_INCOMPATIBLE;
break;
}
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 (data == NULL) {
rc = EINVAL;
break;
}
if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
rc = MDB_INCOMPATIBLE;
break;
}
if (!(mc->mc_flags & C_INITIALIZED))
rc = mdb_cursor_first(mc, key, data);
else
rc = mdb_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_pad;
data->mv_data = METADATA(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_NEXT:
case MDB_NEXT_DUP:
case MDB_NEXT_NODUP:
if (!(mc->mc_flags & C_INITIALIZED))
rc = mdb_cursor_first(mc, key, data);
else
rc = mdb_cursor_next(mc, key, data, op);
break;
case MDB_PREV:
case MDB_PREV_DUP:
case MDB_PREV_NODUP:
if (!(mc->mc_flags & C_INITIALIZED)) {
rc = mdb_cursor_last(mc, key, data);
if (rc)
break;
mc->mc_flags |= C_INITIALIZED;
mc->mc_ki[mc->mc_top]++;
}
rc = mdb_cursor_prev(mc, key, data, op);
break;
case MDB_FIRST:
rc = mdb_cursor_first(mc, key, data);
break;
case MDB_FIRST_DUP:
mfunc = mdb_cursor_first;
mmove:
if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
rc = EINVAL;
break;
}
if (mc->mc_xcursor == NULL) {
rc = MDB_INCOMPATIBLE;
break;
}
{
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 = mdb_node_read(mc->mc_txn, leaf, data);
break;
}
}
if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
rc = EINVAL;
break;
}
rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
break;
case MDB_LAST:
rc = mdb_cursor_last(mc, key, data);
break;
case MDB_LAST_DUP:
mfunc = mdb_cursor_last;
goto mmove;
default:
DPRINTF(("unhandled/unimplemented cursor operation %u", op));
rc = EINVAL;
break;
}
if (mc->mc_flags & C_DEL)
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
mdb_cursor_touch(MDB_cursor *mc)
{
int rc = MDB_SUCCESS;
if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
MDB_cursor mc2;
MDB_xcursor mcx;
if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
return MDB_BAD_DBI;
mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
if (rc)
return rc;
*mc->mc_dbflag |= DB_DIRTY;
}
mc->mc_top = 0;
if (mc->mc_snum) {
do {
rc = mdb_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
mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
unsigned int flags)
{
enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
MDB_env *env;
MDB_node *leaf = NULL;
MDB_page *fp, *mp;
uint16_t fp_flags;
MDB_val xdata, *rdata, dkey, olddata;
MDB_db dummy;
int do_sub = 0, insert_key, insert_data;
unsigned int mcount = 0, dcount = 0, nospill;
size_t nsize;
int rc, rc2;
unsigned int nflags;
DKBUF;
if (mc == NULL || key == NULL)
return EINVAL;
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 (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
return MDB_INCOMPATIBLE;
}
nospill = flags & MDB_NOSPILL;
flags &= ~MDB_NOSPILL;
if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
if (key->mv_size-1 >= ENV_MAXKEY(env))
return MDB_BAD_VALSIZE;
#if SIZE_MAX > MAXDATASIZE
if (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) && data->mv_size > ENV_MAXKEY(env))
return MDB_BAD_VALSIZE;
#endif
DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
dkey.mv_size = 0;
if (flags == MDB_CURRENT) {
if (!(mc->mc_flags & C_INITIALIZED))
return EINVAL;
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 = mdb_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 = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
}
if ((flags & MDB_NOOVERWRITE) && rc == 0) {
DPRINTF(("duplicate key [%s]", DKEY(key)));
*data = d2;
return MDB_KEYEXIST;
}
if (rc && rc != MDB_NOTFOUND)
return rc;
}
if (mc->mc_flags & C_DEL)
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 ((rc2 = mdb_page_spill(mc, key, rdata)))
return rc2;
}
if (rc == MDB_NO_ROOT) {
MDB_page *np;
/* new database, write a root leaf page */
DPUTS("allocating new root leaf page");
if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
return rc2;
}
mdb_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 = mdb_cursor_touch(mc);
if (rc2)
return rc2;
}
insert_key = insert_data = rc;
if (insert_key) {
/* The key does not exist */
DPRINTF(("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_pad = 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 int ksize = mc->mc_db->md_pad;
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 top = mc->mc_top;
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--;
if (mc->mc_ki[mc->mc_top])
rc2 = mdb_update_key(mc, key);
else
rc2 = MDB_SUCCESS;
mc->mc_top = top;
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)
goto current;
#if UINT_MAX < SIZE_MAX
if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
mc->mc_dbx->md_dcmp = mdb_cmp_clong;
#endif
/* does data match? */
if (!mc->mc_dbx->md_dcmp(data, &olddata)) {
if (flags & MDB_NODUPDATA)
return MDB_KEYEXIST;
/* overwrite it */
goto current;
}
/* Back up original data item */
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_pad = 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_pad;
if (SIZELEFT(fp) < offset) {
offset *= 4; /* space for 4 more */
break;
}
/* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
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_pad = fp->mp_pad;
dummy.md_flags = MDB_DUPFIXED;
if (mc->mc_db->md_flags & MDB_INTEGERDUP)
dummy.md_flags |= MDB_INTEGERKEY;
} else {
dummy.md_pad = 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 = mdb_page_alloc(mc, 1, &mp)))
return rc;
offset = env->me_psize - olddata.mv_size;
flags |= F_DUPDATA|F_SUBDATA;
dummy.md_root = mp->mp_pgno;
}
if (mp != fp) {
mp->mp_flags = fp_flags | P_DIRTY;
mp->mp_pad = fp->mp_pad;
mp->mp_lower = fp->mp_lower;
mp->mp_upper = fp->mp_upper + offset;
if (fp_flags & P_LEAF2) {
memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
} 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)
mdb_node_del(mc, 0);
goto new_sub;
}
current:
/* 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 ((rc2 = mdb_page_get(mc->mc_txn, 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 = mdb_page_unspill(mc->mc_txn, omp, &omp);
if (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 (level > 1) {
/* It is writable only in a parent txn */
size_t sz = (size_t) env->me_psize * ovpages, off;
MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
MDB_ID2 id2;
if (!np)
return ENOMEM;
id2.mid = pg;
id2.mptr = np;
rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
mdb_cassert(mc, rc2 == 0);
if (!(flags & MDB_RESERVE)) {
/* 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 beginning of page */
omp = np;
}
SETDSZ(leaf, data->mv_size);
if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = METADATA(omp);
else
memcpy(METADATA(omp), data->mv_data, data->mv_size);
return MDB_SUCCESS;
}
}
if ((rc2 = mdb_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;
}
mdb_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 : mdb_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 = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
} else {
/* There is room already in this leaf page. */
rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
if (rc == 0 && insert_key) {
/* 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) continue;
if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
m3->mc_ki[i]++;
}
}
}
}
if (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 = MDB_CURRENT|MDB_NOSPILL;
} else {
mdb_xcursor_init1(mc, leaf);
xflags = (flags & MDB_NODUPDATA) ?
MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
}
/* converted, write the original data first */
if (dkey.mv_size) {
rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
if (rc)
goto bad_sub;
{
/* Adjust other cursors pointing to mp */
MDB_cursor *m2;
unsigned i = mc->mc_top;
MDB_page *mp = mc->mc_pg[i];
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 && m2->mc_ki[i] == mc->mc_ki[i]) {
mdb_xcursor_init1(m2, leaf);
}
}
}
/* we've done our job */
dkey.mv_size = 0;
}
ecount = mc->mc_xcursor->mx_db.md_entries;
if (flags & MDB_APPENDDUP)
xflags |= MDB_APPEND;
rc = mdb_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 (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 (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */
rc = MDB_CORRUPTED;
}
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
int
mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
{
MDB_node *leaf;
MDB_page *mp;
int rc;
if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
if (!(mc->mc_flags & C_INITIALIZED))
return EINVAL;
if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
return MDB_NOTFOUND;
if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
return rc;
rc = mdb_cursor_touch(mc);
if (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) {
/* mdb_cursor_del0() will subtract the final entry */
mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
} else {
if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
}
rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
if (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 */
mdb_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 this fake 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_pg[mc->mc_top] == mp &&
m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
}
}
mc->mc_db->md_entries--;
mc->mc_flags |= C_DEL;
return rc;
}
/* 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 = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
if (rc)
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 ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
(rc = mdb_ovpage_free(mc, omp)))
goto fail;
}
del_key:
return mdb_cursor_del0(mc);
fail:
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
/** Allocate and initialize new pages for a database.
* @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
mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
{
MDB_page *np;
int rc;
if ((rc = mdb_page_alloc(mc, num, &np)))
return rc;
DPRINTF(("allocated new mpage %"Z"u, 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 size_t
mdb_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 size_t
mdb_branch_size(MDB_env *env, MDB_val *key)
{
size_t sz;
sz = INDXSIZE(key);
if (sz > env->me_nodemax) {
/* put on overflow page */
/* not implemented */
/* sz -= key->size - sizeof(pgno_t); */
}
return sz + sizeof(indx_t);
}
/** Add a node to the page pointed to by the cursor.
* @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:
* <ul>
* <li>ENOMEM - failed to allocate overflow pages for the node.
* <li>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.
* </ul>
*/
static int
mdb_node_add(MDB_cursor *mc, indx_t indx,
MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
{
unsigned int 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 */
DKBUF;
mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
IS_LEAF(mp) ? "leaf" : "branch",
IS_SUBP(mp) ? "sub-" : "",
mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
key ? key->mv_size : 0, key ? DKEY(key) : "null"));
if (IS_LEAF2(mp)) {
/* Move higher keys up one slot. */
int ksize = mc->mc_db->md_pad, 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)) {
mdb_cassert(mc, data);
if (F_ISSET(flags, F_BIGDATA)) {
/* Data already on overflow page. */
node_size += sizeof(pgno_t);
} else if (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. */
DPRINTF(("data size is %"Z"u, node would be %"Z"u, 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 = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
return rc;
DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
flags |= F_BIGDATA;
goto update;
} else {
node_size += data->mv_size;
}
}
node_size = EVEN(node_size);
if ((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;
mdb_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)) {
mdb_cassert(mc, key);
if (ofp == NULL) {
if (F_ISSET(flags, F_BIGDATA))
memcpy(node->mn_data + key->mv_size, data->mv_data,
sizeof(pgno_t));
else if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = node->mn_data + key->mv_size;
else
memcpy(node->mn_data + key->mv_size, data->mv_data,
data->mv_size);
} else {
memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
sizeof(pgno_t));
if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = METADATA(ofp);
else
memcpy(METADATA(ofp), data->mv_data, data->mv_size);
}
}
return MDB_SUCCESS;
full:
DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
mdb_dbg_pgno(mp), NUMKEYS(mp)));
DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
DPRINTF(("node size = %"Z"u", 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
mdb_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 int sz;
indx_t i, j, numkeys, ptr;
MDB_node *node;
char *base;
DPRINTF(("delete node %u on %s page %"Z"u", indx,
IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
numkeys = NUMKEYS(mp);
mdb_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
mdb_node_shrink(MDB_page *mp, indx_t indx)
{
MDB_node *node;
MDB_page *sp, *xp;
char *base;
int nsize, delta;
indx_t i, numkeys, ptr;
node = NODEPTR(mp, indx);
sp = (MDB_page *)NODEDATA(node);
delta = SIZELEFT(sp);
xp = (MDB_page *)((char *)sp + delta);
/* shift subpage upward */
if (IS_LEAF2(sp)) {
nsize = NUMKEYS(sp) * sp->mp_pad;
if (nsize & 1)
return; /* do not make the node uneven-sized */
memmove(METADATA(xp), METADATA(sp), nsize);
} else {
int i;
numkeys = NUMKEYS(sp);
for (i=numkeys-1; i>=0; i--)
xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
}
xp->mp_upper = sp->mp_lower;
xp->mp_lower = sp->mp_lower;
xp->mp_flags = sp->mp_flags;
xp->mp_pad = sp->mp_pad;
COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
nsize = NODEDSZ(node) - delta;
SETDSZ(node, nsize);
/* shift lower nodes upward */
ptr = mp->mp_ptrs[indx];
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;
memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
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
mdb_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;
mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
}
/** 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
mdb_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_pad = mc->mc_pg[mc->mc_top]->mp_pad;
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_pad = fp->mp_pad;
if (mc->mc_db->md_flags & MDB_INTEGERDUP)
mx->mx_db.md_flags |= MDB_INTEGERKEY;
}
}
DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
mx->mx_db.md_root));
mx->mx_dbflag = DB_VALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
#if UINT_MAX < SIZE_MAX
if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
mx->mx_dbx.md_cmp = mdb_cmp_clong;
#endif
}
/** Initialize a cursor for a given transaction and database. */
static void
mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
{
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;
if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
mdb_tassert(txn, mx != NULL);
mc->mc_xcursor = mx;
mdb_xcursor_init0(mc);
} else {
mc->mc_xcursor = NULL;
}
if (*mc->mc_dbflag & DB_STALE) {
mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
}
}
int
mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
{
MDB_cursor *mc;
size_t size = sizeof(MDB_cursor);
if (!ret || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
return MDB_BAD_TXN;
/* Allow read access to the freelist */
if (!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 ((mc = malloc(size)) != NULL) {
mdb_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
mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
{
if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi))
return EINVAL;
if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
return MDB_BAD_TXN;
mdb_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
mdb_cursor_count(MDB_cursor *mc, size_t *countp)
{
MDB_node *leaf;
if (mc == NULL || countp == NULL)
return EINVAL;
if (mc->mc_xcursor == NULL)
return MDB_INCOMPATIBLE;
if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
return MDB_BAD_TXN;
if (!(mc->mc_flags & C_INITIALIZED))
return EINVAL;
if (!mc->mc_snum || (mc->mc_flags & C_EOF))
return MDB_NOTFOUND;
leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
*countp = 1;
} else {
if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
return EINVAL;
*countp = mc->mc_xcursor->mx_db.md_entries;
}
return MDB_SUCCESS;
}
void
mdb_cursor_close(MDB_cursor *mc)
{
if (mc && !mc->mc_backup) {
/* remove from txn, if tracked */
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;
}
free(mc);
}
}
MDB_txn *
mdb_cursor_txn(MDB_cursor *mc)
{
if (!mc) return NULL;
return mc->mc_txn;
}
MDB_dbi
mdb_cursor_dbi(MDB_cursor *mc)
{
return mc->mc_dbi;
}
/** Replace the key for a branch node with a new key.
* @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
mdb_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];
#if MDB_DEBUG
{
MDB_val k2;
char kbuf2[DKBUF_MAXKEYSIZE*2+1];
k2.mv_data = NODEKEY(node);
k2.mv_size = node->mn_ksize;
DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
indx, ptr,
mdb_dkey(&k2, kbuf2),
DKEY(key),
mp->mp_pgno));
}
#endif
/* 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 */
DPRINTF(("Not enough room, delta = %d, splitting...", delta));
pgno = NODEPGNO(node);
mdb_node_del(mc, 0);
return mdb_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
mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
/** Move a node from csrc to cdst.
*/
static int
mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
{
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 ((rc = mdb_page_touch(csrc)) ||
(rc = mdb_page_touch(cdst)))
return rc;
if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
key.mv_size = csrc->mc_db->md_pad;
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]);
mdb_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 int snum = csrc->mc_snum;
MDB_node *s2;
/* must find the lowest key below src */
rc = mdb_page_search_lowest(csrc);
if (rc)
return rc;
if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
key.mv_size = csrc->mc_db->md_pad;
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);
}
if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
unsigned int snum = cdst->mc_snum;
MDB_node *s2;
MDB_val bkey;
/* must find the lowest key below dst */
mdb_cursor_copy(cdst, &mn);
rc = mdb_page_search_lowest(&mn);
if (rc)
return rc;
if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
bkey.mv_size = mn.mc_db->md_pad;
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 = mdb_update_key(&mn, &bkey);
if (rc)
return rc;
}
DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
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 = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
if (rc != MDB_SUCCESS)
return rc;
/* Delete the node from the source page.
*/
mdb_node_del(csrc, key.mv_size);
{
/* Adjust other cursors pointing to mp */
MDB_cursor *m2, *m3;
MDB_dbi dbi = csrc->mc_dbi;
MDB_page *mp = csrc->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 == csrc) continue;
if (m3->mc_pg[csrc->mc_top] == mp && 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];
}
}
}
/* 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);
}
DPRINTF(("update separator for source page %"Z"u to [%s]",
csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
mdb_cursor_copy(csrc, &mn);
mn.mc_snum--;
mn.mc_top--;
if ((rc = mdb_update_key(&mn, &key)) != 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 = mdb_update_key(csrc, &nullkey);
csrc->mc_ki[csrc->mc_top] = ix;
mdb_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);
}
DPRINTF(("update separator for destination page %"Z"u to [%s]",
cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
mdb_cursor_copy(cdst, &mn);
mn.mc_snum--;
mn.mc_top--;
if ((rc = mdb_update_key(&mn, &key)) != 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 = mdb_update_key(cdst, &nullkey);
cdst->mc_ki[cdst->mc_top] = ix;
mdb_cassert(csrc, 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
mdb_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];
DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
mdb_cassert(csrc, cdst->mc_snum > 1);
/* Mark dst as dirty. */
if ((rc = mdb_page_touch(cdst)))
return rc;
/* Move all nodes from src to dst.
*/
j = nkeys = NUMKEYS(pdst);
if (IS_LEAF2(psrc)) {
key.mv_size = csrc->mc_db->md_pad;
key.mv_data = METADATA(psrc);
for (i = 0; i < NUMKEYS(psrc); i++, j++) {
rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
if (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;
mdb_cursor_copy(csrc, &mn);
/* must find the lowest key below src */
rc = mdb_page_search_lowest(&mn);
if (rc)
return rc;
if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
key.mv_size = mn.mc_db->md_pad;
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 = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
if (rc != MDB_SUCCESS)
return rc;
}
}
DPRINTF(("dst page %"Z"u 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--;
mdb_node_del(csrc, 0);
if (csrc->mc_ki[csrc->mc_top] == 0) {
key.mv_size = 0;
rc = mdb_update_key(csrc, &key);
if (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 = mdb_page_loose(csrc, psrc);
if (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;
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[csrc->mc_top] == psrc) {
m3->mc_pg[csrc->mc_top] = pdst;
m3->mc_ki[csrc->mc_top] += nkeys;
}
}
}
{
unsigned int snum = cdst->mc_snum;
uint16_t depth = cdst->mc_db->md_depth;
mdb_cursor_pop(cdst);
rc = mdb_rebalance(cdst);
/* Did the tree shrink? */
if (depth > cdst->mc_db->md_depth)
snum--;
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
mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
{
unsigned int 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
mdb_rebalance(MDB_cursor *mc)
{
MDB_node *node;
int rc;
unsigned int ptop, minkeys;
MDB_cursor mn;
indx_t oldki;
minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
mdb_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]) >= FILL_THRESHOLD &&
NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
return MDB_SUCCESS;
}
if (mc->mc_snum < 2) {
MDB_page *mp = mc->mc_pg[0];
if (IS_SUBP(mp)) {
DPUTS("Can't rebalance a subpage, ignoring");
return MDB_SUCCESS;
}
if (NUMKEYS(mp) == 0) {
DPUTS("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 = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
if (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_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;
DPUTS("collapsing root page!");
rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
if (rc)
return rc;
mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
if (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 || m3->mc_snum < mc->mc_snum) continue;
if (m3->mc_pg[0] == mp) {
m3->mc_snum--;
m3->mc_top--;
for (i=0; i<m3->mc_snum; i++) {
m3->mc_pg[i] = m3->mc_pg[i+1];
m3->mc_ki[i] = m3->mc_ki[i+1];
}
}
}
}
} else
DPUTS("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;
mdb_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.
*/
mdb_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.
*/
DPUTS("reading right neighbor");
mn.mc_ki[ptop]++;
node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
if (rc)
return rc;
mn.mc_ki[mn.mc_top] = 0;
mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
} else {
/* There is at least one neighbor to the left.
*/
DPUTS("reading left neighbor");
mn.mc_ki[ptop]--;
node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
if (rc)
return rc;
mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
mc->mc_ki[mc->mc_top] = 0;
}
DPRINTF(("found neighbor page %"Z"u (%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.)
*/
minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
rc = mdb_node_move(&mn, mc);
if (mc->mc_ki[ptop]) {
oldki++;
}
} else {
if (mc->mc_ki[ptop] == 0) {
rc = mdb_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;
rc = mdb_page_merge(mc, &mn);
mdb_cursor_copy(&mn, mc);
}
mc->mc_flags &= ~C_EOF;
}
mc->mc_ki[mc->mc_top] = oldki;
return rc;
}
/** Complete a delete operation started by #mdb_cursor_del(). */
static int
mdb_cursor_del0(MDB_cursor *mc)
{
int rc;
MDB_page *mp;
indx_t ki;
unsigned int nkeys;
ki = mc->mc_ki[mc->mc_top];
mdb_node_del(mc, mc->mc_db->md_pad);
mc->mc_db->md_entries--;
rc = mdb_rebalance(mc);
if (rc == MDB_SUCCESS) {
MDB_cursor *m2, *m3;
MDB_dbi dbi = mc->mc_dbi;
mp = mc->mc_pg[mc->mc_top];
nkeys = NUMKEYS(mp);
/* if mc points past last node in page, find next sibling */
if (mc->mc_ki[mc->mc_top] >= nkeys) {
rc = mdb_cursor_sibling(mc, 1);
if (rc == MDB_NOTFOUND) {
mc->mc_flags |= C_EOF;
rc = MDB_SUCCESS;
}
}
/* 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 || 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 (m3->mc_ki[mc->mc_top] > ki)
m3->mc_ki[mc->mc_top]--;
else if (mc->mc_db->md_flags & MDB_DUPSORT)
m3->mc_xcursor->mx_cursor.mc_flags |= C_EOF;
}
if (m3->mc_ki[mc->mc_top] >= nkeys) {
rc = mdb_cursor_sibling(m3, 1);
if (rc == MDB_NOTFOUND) {
m3->mc_flags |= C_EOF;
rc = MDB_SUCCESS;
}
}
}
}
mc->mc_flags |= C_DEL;
}
if (rc)
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
int
mdb_del(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data)
{
if (!key || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
/* must ignore any data */
data = NULL;
}
return mdb_del0(txn, dbi, key, data, 0);
}
static int
mdb_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, *xdata;
int rc, exact = 0;
DKBUF;
DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
mdb_cursor_init(&mc, txn, dbi, &mx);
if (data) {
op = MDB_GET_BOTH;
rdata = *data;
xdata = &rdata;
} else {
op = MDB_SET;
xdata = NULL;
flags |= MDB_NODUPDATA;
}
rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
if (rc == 0) {
/* let mdb_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_flags |= C_UNTRACK;
mc.mc_next = txn->mt_cursors[dbi];
txn->mt_cursors[dbi] = &mc;
rc = mdb_cursor_del(&mc, flags);
txn->mt_cursors[dbi] = mc.mc_next;
}
return rc;
}
/** Split a page and insert a new node.
* @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
mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
unsigned int nflags)
{
unsigned int 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);
DPRINTF(("-----> splitting %s page %"Z"u 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 = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
return rc;
DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
if (mc->mc_snum < 2) {
if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
goto done;
/* shift current top to make room for new parent */
mc->mc_pg[1] = mc->mc_pg[0];
mc->mc_ki[1] = mc->mc_ki[0];
mc->mc_pg[0] = pp;
mc->mc_ki[0] = 0;
mc->mc_db->md_root = pp->mp_pgno;
DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
mc->mc_db->md_depth++;
new_root = 1;
/* Add left (implicit) pointer. */
if ((rc = mdb_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 = 2;
mc->mc_top = 1;
ptop = 0;
} else {
ptop = mc->mc_top-1;
DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
}
mc->mc_flags |= C_SPLITTING;
mdb_cursor_copy(mc, &mn);
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 int 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_pad;
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;
mc->mc_pg[mc->mc_top] = rp;
}
} else {
int psize, nsize, k;
/* Maximum free space in an empty page */
pmax = env->me_psize - PAGEHDRSZ;
if (IS_LEAF(mp))
nsize = mdb_leaf_size(env, newkey, newdata);
else
nsize = mdb_branch_size(env, newkey);
nsize = EVEN(nsize);
/* grab a page to hold a temporary copy */
copy = mdb_page_malloc(mc->mc_txn, 1);
if (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 mdb_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+2;
} 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);
}
}
}
DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
/* Copy separator key to the parent.
*/
if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
mn.mc_snum--;
mn.mc_top--;
did_split = 1;
rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
if (rc)
goto done;
/* root split? */
if (mn.mc_snum == mc->mc_snum) {
mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
mc->mc_snum++;
mc->mc_top++;
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];
mdb_cursor_sibling(mc, 0);
}
}
} else {
mn.mc_top--;
rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
mn.mc_top++;
}
mc->mc_flags ^= C_SPLITTING;
if (rc != MDB_SUCCESS) {
goto done;
}
if (nflags & MDB_APPEND) {
mc->mc_pg[mc->mc_top] = rp;
mc->mc_ki[mc->mc_top] = 0;
rc = mdb_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 = mdb_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;
if (nflags & MDB_RESERVE) {
node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
if (!(node->mn_flags & F_BIGDATA))
newdata->mv_data = NODEDATA(node);
}
} 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];
}
}
}
}
{
/* Adjust other cursors pointing to mp */
MDB_cursor *m2, *m3;
MDB_dbi dbi = mc->mc_dbi;
int fixup = 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 (m3->mc_flags & C_SPLITTING)
continue;
if (new_root) {
int k;
/* root split */
for (k=m3->mc_top; 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] >= split_indx) {
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] >= fixup) {
m3->mc_pg[mc->mc_top] = rp;
m3->mc_ki[mc->mc_top] -= fixup;
m3->mc_ki[ptop] = mn.mc_ki[ptop];
}
} 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]++;
}
}
}
DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
done:
if (copy) /* tmp page */
mdb_page_free(env, copy);
if (rc)
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
int
mdb_put(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data, unsigned int flags)
{
MDB_cursor mc;
MDB_xcursor mx;
if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags)
return EINVAL;
mdb_cursor_init(&mc, txn, dbi, &mx);
return mdb_cursor_put(&mc, key, data, flags);
}
#ifndef MDB_WBUF
#define MDB_WBUF (1024*1024)
#endif
/** State needed for a compacting copy. */
typedef struct mdb_copy {
pthread_mutex_t mc_mutex;
pthread_cond_t mc_cond;
char *mc_wbuf[2];
char *mc_over[2];
MDB_env *mc_env;
MDB_txn *mc_txn;
int mc_wlen[2];
int mc_olen[2];
pgno_t mc_next_pgno;
HANDLE mc_fd;
int mc_status;
volatile int mc_new;
int mc_toggle;
} mdb_copy;
/** Dedicated writer thread for compacting copy. */
static THREAD_RET ESECT
mdb_env_copythr(void *arg)
{
mdb_copy *my = arg;
char *ptr;
int toggle = 0, wsize, rc;
#ifdef _WIN32
DWORD len;
#define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
#else
int len;
#define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
#endif
pthread_mutex_lock(&my->mc_mutex);
my->mc_new = 0;
pthread_cond_signal(&my->mc_cond);
for(;;) {
while (!my->mc_new)
pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
if (my->mc_new < 0) {
my->mc_new = 0;
break;
}
my->mc_new = 0;
wsize = my->mc_wlen[toggle];
ptr = my->mc_wbuf[toggle];
again:
while (wsize > 0) {
DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
if (!rc) {
rc = ErrCode();
break;
} else if (len > 0) {
rc = MDB_SUCCESS;
ptr += len;
wsize -= len;
continue;
} else {
rc = EIO;
break;
}
}
if (rc) {
my->mc_status = rc;
break;
}
/* 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;
pthread_cond_signal(&my->mc_cond);
}
pthread_cond_signal(&my->mc_cond);
pthread_mutex_unlock(&my->mc_mutex);
return (THREAD_RET)0;
#undef DO_WRITE
}
/** Tell the writer thread there's a buffer ready to write */
static int ESECT
mdb_env_cthr_toggle(mdb_copy *my, int st)
{
int toggle = my->mc_toggle ^ 1;
pthread_mutex_lock(&my->mc_mutex);
if (my->mc_status) {
pthread_mutex_unlock(&my->mc_mutex);
return my->mc_status;
}
while (my->mc_new == 1)
pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
my->mc_new = st;
my->mc_toggle = toggle;
pthread_cond_signal(&my->mc_cond);
pthread_mutex_unlock(&my->mc_mutex);
return 0;
}
/** Depth-first tree traversal for compacting copy. */
static int ESECT
mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
{
MDB_cursor mc;
MDB_txn *txn = my->mc_txn;
MDB_node *ni;
MDB_page *mo, *mp, *leaf;
char *buf, *ptr;
int rc, toggle;
unsigned int i;
/* Empty DB, nothing to do */
if (*pg == P_INVALID)
return MDB_SUCCESS;
mc.mc_snum = 1;
mc.mc_top = 0;
mc.mc_txn = txn;
rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
if (rc)
return rc;
rc = mdb_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++) {
mdb_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;
mdb_page_copy(leaf, mp, my->mc_env->me_psize);
mp = leaf;
ni = NODEPTR(mp, i);
}
memcpy(&pg, NODEDATA(ni), sizeof(pg));
rc = mdb_page_get(txn, pg, &omp, NULL);
if (rc)
goto done;
if (my->mc_wlen[toggle] >= MDB_WBUF) {
rc = mdb_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 = mdb_env_cthr_toggle(my, 1);
if (rc)
goto done;
toggle = my->mc_toggle;
}
memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
} else if (ni->mn_flags & F_SUBDATA) {
MDB_db db;
/* Need writable leaf */
if (mp != leaf) {
mc.mc_pg[mc.mc_top] = leaf;
mdb_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 = mdb_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 = mdb_page_get(txn, 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.
*/
mdb_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 = mdb_env_cthr_toggle(my, 1);
if (rc)
goto done;
toggle = my->mc_toggle;
}
mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
mdb_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);
mdb_cursor_pop(&mc);
} else {
/* Otherwise we're done */
*pg = mo->mp_pgno;
break;
}
}
done:
free(buf);
return rc;
}
/** Copy environment with compaction. */
static int ESECT
mdb_env_copyfd1(MDB_env *env, HANDLE fd)
{
MDB_meta *mm;
MDB_page *mp;
mdb_copy my;
MDB_txn *txn = NULL;
pthread_t thr;
int rc;
#ifdef _WIN32
my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
if (my.mc_wbuf[0] == NULL)
return errno;
#else
pthread_mutex_init(&my.mc_mutex, NULL);
pthread_cond_init(&my.mc_cond, NULL);
#ifdef HAVE_MEMALIGN
my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
if (my.mc_wbuf[0] == NULL)
return errno;
#else
rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
if (rc)
return rc;
#endif
#endif
memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
my.mc_wlen[0] = 0;
my.mc_wlen[1] = 0;
my.mc_olen[0] = 0;
my.mc_olen[1] = 0;
my.mc_next_pgno = 2;
my.mc_status = 0;
my.mc_new = 1;
my.mc_toggle = 0;
my.mc_env = env;
my.mc_fd = fd;
THREAD_CREATE(thr, mdb_env_copythr, &my);
rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
if (rc)
return rc;
mp = (MDB_page *)my.mc_wbuf[0];
memset(mp, 0, 2*env->me_psize);
mp->mp_pgno = 0;
mp->mp_flags = P_META;
mm = (MDB_meta *)METADATA(mp);
mdb_env_init_meta0(env, mm);
mm->mm_address = env->me_metas[0]->mm_address;
mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
mp->mp_pgno = 1;
mp->mp_flags = P_META;
*(MDB_meta *)METADATA(mp) = *mm;
mm = (MDB_meta *)METADATA(mp);
/* Count the number of free pages, subtract from lastpg to find
* number of active pages
*/
{
MDB_ID freecount = 0;
MDB_cursor mc;
MDB_val key, data;
mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
freecount += *(MDB_ID *)data.mv_data;
freecount += txn->mt_dbs[0].md_branch_pages +
txn->mt_dbs[0].md_leaf_pages +
txn->mt_dbs[0].md_overflow_pages;
/* Set metapage 1 */
mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
mm->mm_dbs[1] = txn->mt_dbs[1];
mm->mm_dbs[1].md_root = mm->mm_last_pg;
mm->mm_txnid = 1;
}
my.mc_wlen[0] = env->me_psize * 2;
my.mc_txn = txn;
pthread_mutex_lock(&my.mc_mutex);
while(my.mc_new)
pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
pthread_mutex_unlock(&my.mc_mutex);
rc = mdb_env_cwalk(&my, &txn->mt_dbs[1].md_root, 0);
if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
rc = mdb_env_cthr_toggle(&my, 1);
mdb_env_cthr_toggle(&my, -1);
pthread_mutex_lock(&my.mc_mutex);
while(my.mc_new)
pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
pthread_mutex_unlock(&my.mc_mutex);
THREAD_FINISH(thr);
mdb_txn_abort(txn);
#ifdef _WIN32
CloseHandle(my.mc_cond);
CloseHandle(my.mc_mutex);
_aligned_free(my.mc_wbuf[0]);
#else
pthread_cond_destroy(&my.mc_cond);
pthread_mutex_destroy(&my.mc_mutex);
free(my.mc_wbuf[0]);
#endif
return rc;
}
/** Copy environment as-is. */
static int ESECT
mdb_env_copyfd0(MDB_env *env, HANDLE fd)
{
MDB_txn *txn = NULL;
int rc;
size_t wsize;
char *ptr;
#ifdef _WIN32
DWORD len, w2;
#define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
#else
ssize_t len;
size_t w2;
#define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
#endif
/* Do the lock/unlock of the reader mutex before starting the
* write txn. Otherwise other read txns could block writers.
*/
rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
if (rc)
return rc;
if (env->me_txns) {
/* We must start the actual read txn after blocking writers */
mdb_txn_reset0(txn, "reset-stage1");
/* Temporarily block writers until we snapshot the meta pages */
LOCK_MUTEX_W(env);
rc = mdb_txn_renew0(txn);
if (rc) {
UNLOCK_MUTEX_W(env);
goto leave;
}
}
wsize = env->me_psize * 2;
ptr = env->me_map;
w2 = wsize;
while (w2 > 0) {
DO_WRITE(rc, fd, ptr, w2, len);
if (!rc) {
rc = ErrCode();
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;
}
}
if (env->me_txns)
UNLOCK_MUTEX_W(env);
if (rc)
goto leave;
w2 = txn->mt_next_pgno * env->me_psize;
#ifdef WIN32
{
LARGE_INTEGER fsize;
GetFileSizeEx(env->me_fd, &fsize);
if (w2 > fsize.QuadPart)
w2 = fsize.QuadPart;
}
#else
{
struct stat st;
fstat(env->me_fd, &st);
if (w2 > (size_t)st.st_size)
w2 = st.st_size;
}
#endif
wsize = w2 - wsize;
while (wsize > 0) {
if (wsize > MAX_WRITE)
w2 = MAX_WRITE;
else
w2 = wsize;
DO_WRITE(rc, fd, ptr, w2, len);
if (!rc) {
rc = ErrCode();
break;
} else if (len > 0) {
rc = MDB_SUCCESS;
ptr += len;
wsize -= len;
continue;
} else {
rc = EIO;
break;
}
}
leave:
mdb_txn_abort(txn);
return rc;
}
int ESECT
mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
{
if (flags & MDB_CP_COMPACT)
return mdb_env_copyfd1(env, fd);
else
return mdb_env_copyfd0(env, fd);
}
int ESECT
mdb_env_copyfd(MDB_env *env, HANDLE fd)
{
return mdb_env_copyfd2(env, fd, 0);
}
int ESECT
mdb_env_copy2(MDB_env *env, const char *path, unsigned int 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.
*/
#ifdef _WIN32
newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
#else
newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
#endif
if (newfd == INVALID_HANDLE_VALUE) {
rc = ErrCode();
goto leave;
}
if (env->me_psize >= env->me_os_psize) {
#ifdef 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
#ifdef F_NOCACHE /* __APPLE__ */
rc = fcntl(newfd, F_NOCACHE, 1);
if (rc) {
rc = ErrCode();
goto leave;
}
#endif
}
rc = mdb_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 = ErrCode();
return rc;
}
int ESECT
mdb_env_copy(MDB_env *env, const char *path)
{
return mdb_env_copy2(env, path, 0);
}
int ESECT
mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
{
if ((flag & CHANGEABLE) != flag)
return EINVAL;
if (onoff)
env->me_flags |= flag;
else
env->me_flags &= ~flag;
return MDB_SUCCESS;
}
int ESECT
mdb_env_get_flags(MDB_env *env, unsigned int *arg)
{
if (!env || !arg)
return EINVAL;
*arg = env->me_flags;
return MDB_SUCCESS;
}
int ESECT
mdb_env_set_userctx(MDB_env *env, void *ctx)
{
if (!env)
return EINVAL;
env->me_userctx = ctx;
return MDB_SUCCESS;
}
void * ESECT
mdb_env_get_userctx(MDB_env *env)
{
return env ? env->me_userctx : NULL;
}
int ESECT
mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
{
if (!env)
return EINVAL;
#ifndef NDEBUG
env->me_assert_func = func;
#endif
return MDB_SUCCESS;
}
int ESECT
mdb_env_get_path(MDB_env *env, const char **arg)
{
if (!env || !arg)
return EINVAL;
*arg = env->me_path;
return MDB_SUCCESS;
}
int ESECT
mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
{
if (!env || !arg)
return EINVAL;
*arg = env->me_fd;
return MDB_SUCCESS;
}
/** Common code for #mdb_stat() and #mdb_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 ESECT
mdb_stat0(MDB_env *env, MDB_db *db, MDB_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 ESECT
mdb_env_stat(MDB_env *env, MDB_stat *arg)
{
int toggle;
if (env == NULL || arg == NULL)
return EINVAL;
toggle = mdb_env_pick_meta(env);
return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
}
int ESECT
mdb_env_info(MDB_env *env, MDB_envinfo *arg)
{
int toggle;
if (env == NULL || arg == NULL)
return EINVAL;
toggle = mdb_env_pick_meta(env);
arg->me_mapaddr = env->me_metas[toggle]->mm_address;
arg->me_mapsize = env->me_mapsize;
arg->me_maxreaders = env->me_maxreaders;
/* me_numreaders may be zero if this process never used any readers. Use
* the shared numreader count if it exists.
*/
arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
return MDB_SUCCESS;
}
/** 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 #mdb_set_compare() or
* #mdb_set_dupsort().
* @param[in] txn A transaction handle returned by #mdb_txn_begin()
* @param[in] dbi A database handle returned by #mdb_dbi_open()
*/
static void
mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
{
uint16_t f = txn->mt_dbs[dbi].md_flags;
txn->mt_dbxs[dbi].md_cmp =
(f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
(f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
txn->mt_dbxs[dbi].md_dcmp =
!(f & MDB_DUPSORT) ? 0 :
((f & MDB_INTEGERDUP)
? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
: ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
}
int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
{
MDB_val key, data;
MDB_dbi i;
MDB_cursor mc;
MDB_db dummy;
int rc, dbflag, exact;
unsigned int unused = 0, seq;
size_t len;
if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
mdb_default_cmp(txn, FREE_DBI);
}
if ((flags & VALID_FLAGS) != flags)
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
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;
}
}
mdb_default_cmp(txn, MAIN_DBI);
return MDB_SUCCESS;
}
if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
mdb_default_cmp(txn, MAIN_DBI);
}
/* Is the DB already open? */
len = strlen(name);
for (i=2; 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 && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
return MDB_DBS_FULL;
/* Cannot mix named databases with some mainDB flags */
if (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;
exact = 0;
key.mv_size = len;
key.mv_data = (void *)name;
mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
if (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 (!(node->mn_flags & F_SUBDATA))
return MDB_INCOMPATIBLE;
} else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
/* Create if requested */
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;
rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
dbflag |= DB_DIRTY;
}
/* OK, got info, add to table */
if (rc == MDB_SUCCESS) {
unsigned int slot = unused ? unused : txn->mt_numdbs;
txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
txn->mt_dbxs[slot].md_name.mv_size = len;
txn->mt_dbxs[slot].md_rel = NULL;
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;
mdb_default_cmp(txn, slot);
if (!unused) {
txn->mt_numdbs++;
}
}
return rc;
}
int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
{
if (!arg || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
return MDB_BAD_TXN;
if (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. */
mdb_cursor_init(&mc, txn, dbi, &mx);
}
return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
}
void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
{
char *ptr;
if (dbi <= MAIN_DBI || 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 mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
{
/* We could return the flags for the FREE_DBI too but what's the point? */
if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
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
mdb_drop0(MDB_cursor *mc, int subs)
{
int rc;
rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
if (rc == MDB_SUCCESS) {
MDB_txn *txn = mc->mc_txn;
MDB_node *ni;
MDB_cursor mx;
unsigned int i;
/* LEAF2 pages have no nodes, cannot have sub-DBs */
if (IS_LEAF2(mc->mc_pg[mc->mc_top]))
mdb_cursor_pop(mc);
mdb_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 = mdb_page_get(txn, pg, &omp, NULL);
if (rc != 0)
goto done;
mdb_cassert(mc, IS_OVERFLOW(omp));
rc = mdb_midl_append_range(&txn->mt_free_pgs,
pg, omp->mp_pages);
if (rc)
goto done;
} else if (subs && (ni->mn_flags & F_SUBDATA)) {
mdb_xcursor_init1(mc, ni);
rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
if (rc)
goto done;
}
}
} else {
if ((rc = mdb_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 */
mdb_midl_xappend(txn->mt_free_pgs, pg);
}
}
if (!mc->mc_top)
break;
mc->mc_ki[mc->mc_top] = i;
rc = mdb_cursor_sibling(mc, 1);
if (rc) {
if (rc != MDB_NOTFOUND)
goto done;
/* no more siblings, go back to beginning
* of previous level.
*/
mdb_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 = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
done:
if (rc)
txn->mt_flags |= MDB_TXN_ERROR;
} else if (rc == MDB_NOTFOUND) {
rc = MDB_SUCCESS;
}
return rc;
}
int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
{
MDB_cursor *mc, *m2;
int rc;
if ((unsigned)del > 1 || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
return EACCES;
if (dbi > MAIN_DBI && TXN_DBI_CHANGED(txn, dbi))
return MDB_BAD_DBI;
rc = mdb_cursor_open(txn, dbi, &mc);
if (rc)
return rc;
rc = mdb_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 (rc)
goto leave;
/* Can't delete the main DB */
if (del && dbi > MAIN_DBI) {
rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, 0);
if (!rc) {
txn->mt_dbflags[dbi] = DB_STALE;
mdb_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:
mdb_cursor_close(mc);
return rc;
}
int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
{
if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
txn->mt_dbxs[dbi].md_cmp = cmp;
return MDB_SUCCESS;
}
int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
{
if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
txn->mt_dbxs[dbi].md_dcmp = cmp;
return MDB_SUCCESS;
}
int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
{
if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
txn->mt_dbxs[dbi].md_rel = rel;
return MDB_SUCCESS;
}
int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
{
if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
return EINVAL;
txn->mt_dbxs[dbi].md_relctx = ctx;
return MDB_SUCCESS;
}
int ESECT
mdb_env_get_maxkeysize(MDB_env *env)
{
return ENV_MAXKEY(env);
}
int ESECT
mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
{
unsigned int i, rdrs;
MDB_reader *mr;
char buf[64];
int rc = 0, first = 1;
if (!env || !func)
return -1;
if (!env->me_txns) {
return func("(no reader locks)\n", ctx);
}
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;
sprintf(buf, txnid == (txnid_t)-1 ?
"%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\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 ESECT
mdb_pid_insert(MDB_PID_T *ids, MDB_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 ESECT
mdb_reader_check(MDB_env *env, int *dead)
{
unsigned int i, j, rdrs;
MDB_reader *mr;
MDB_PID_T *pids, pid;
int count = 0;
if (!env)
return EINVAL;
if (dead)
*dead = 0;
if (!env->me_txns)
return MDB_SUCCESS;
rdrs = env->me_txns->mti_numreaders;
pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
if (!pids)
return ENOMEM;
pids[0] = 0;
mr = env->me_txns->mti_readers;
for (i=0; i<rdrs; i++) {
if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
pid = mr[i].mr_pid;
if (mdb_pid_insert(pids, pid) == 0) {
if (!mdb_reader_pid(env, Pidcheck, pid)) {
LOCK_MUTEX_R(env);
/* Recheck, a new process may have reused pid */
if (!mdb_reader_pid(env, Pidcheck, pid)) {
for (j=i; j<rdrs; j++)
if (mr[j].mr_pid == pid) {
DPRINTF(("clear stale reader pid %u txn %"Z"d",
(unsigned) pid, mr[j].mr_txnid));
mr[j].mr_pid = 0;
count++;
}
}
UNLOCK_MUTEX_R(env);
}
}
}
}
free(pids);
if (dead)
*dead = count;
return MDB_SUCCESS;
}
/** @} */
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