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mdbx: update DB format and signatures.

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Change-Id: I9c4b187e8ebc3df63fef15ae98872e27d56a01ab
This commit is contained in:
Leo Yuriev
2017-05-30 16:22:42 +03:00
parent d99b2a4b16
commit 61a3766e23
3 changed files with 100 additions and 86 deletions
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87
src/bits.h
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@@ -25,7 +25,7 @@
/* Features under development */
#ifndef MDBX_DEVEL
# define MDBX_DEVEL 0
# define MDBX_DEVEL 1
#endif
/*----------------------------------------------------------------------------*/
@@ -116,12 +116,12 @@
/* A stamp that identifies a file as an MDBX file.
* There's nothing special about this value other than that it is easily
* recognizable, and it will reflect any byte order mismatches. */
#define MDBX_MAGIC 0xBEEFC0DE
#define MDBX_MAGIC UINT64_C(/* 56-bit prime */ 0x59659DBDEF4C11)
/* The version number for a database's datafile format. */
#define MDBX_DATA_VERSION ((MDBX_DEVEL) ? 999 : 1)
#define MDBX_DATA_VERSION ((MDBX_DEVEL) ? 255 : 2)
/* The version number for a database's lockfile format. */
#define MDBX_LOCK_VERSION ((MDBX_DEVEL) ? 999 : 1)
#define MDBX_LOCK_VERSION ((MDBX_DEVEL) ? 255 : 2)
/* handle for the DB used to track free pages. */
#define FREE_DBI 0
@@ -241,21 +241,29 @@ typedef struct MDBX_db {
uint64_t md_leaf_pages; /* number of leaf pages */
uint64_t md_overflow_pages; /* number of overflow pages */
uint64_t md_entries; /* number of data items */
uint64_t md_merkle; /* Merkle tree checksum */
} MDBX_db;
/* 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 MDBX_meta {
/* Stamp identifying this as an MDBX file. It must be set
* to MDBX_MAGIC. */
uint32_t mm_magic;
/* Version number of this file. Must be set to MDBX_DATA_VERSION. */
uint32_t mm_version;
/* txnid that committed this page, */
volatile txnid_t mm_txnid_top;
/* Stamp identifying this as an MDBX file.
* It must be set to MDBX_MAGIC with MDBX_DATA_VERSION. */
uint64_t mm_magic_and_version;
uint64_t mm_mapsize; /* size of mmap region */
/* txnid that committed this page, the first of a two-phase-update pair */
volatile txnid_t mm_txnid_a;
uint16_t mm_extra_flags; /* extra DB flags, zero (nothing) for now */
uint8_t mm_validator_id; /* ID of checksum and page validation method,
* zero (nothing) for now */
uint8_t mm_extra_pagehdr; /* extra bytes in the page header,
* zero (nothing) for now */
uint32_t mm_reserved_pad; /* padding for aligment, unused for now */
uint64_t mm_dbsize_min; /* minimal size of db */
uint64_t mm_dbsize_max; /* maximal size of db */
MDBX_db mm_dbs[CORE_DBS]; /* first is free space, 2nd is main db */
/* The size of pages used in this DB */
#define mm_psize mm_dbs[FREE_DBI].md_xsize
@@ -265,17 +273,20 @@ typedef struct MDBX_meta {
/* Last used page in the datafile.
* Actually the file may be shorter if the freeDB lists the final pages. */
uint64_t mm_last_pg;
#define MDBX_DATASIGN_NONE 0u
#define MDBX_DATASIGN_WEAK 1u
volatile uint64_t mm_datasync_sign;
#define SIGN_IS_WEAK(sign) ((sign) == MDBX_DATASIGN_WEAK)
#define SIGN_IS_STEADY(sign) ((sign) > MDBX_DATASIGN_WEAK)
#define META_IS_WEAK(meta) SIGN_IS_WEAK((meta)->mm_datasync_sign)
#define META_IS_STEADY(meta) SIGN_IS_STEADY((meta)->mm_datasync_sign)
/* txnid that committed this page */
volatile txnid_t mm_txnid_bottom;
volatile uint64_t mm_datasync_sign;
/* to be removed */
uint64_t mm_mapsize; /* current size of mmap region */
/* txnid that committed this page, the second of a two-phase-update pair */
volatile txnid_t mm_txnid_b;
} MDBX_meta;
/* Common header for all page types. The page type depends on mp_flags.
@@ -297,7 +308,8 @@ typedef struct MDBX_meta {
* in the snapshot: Either used by a database or listed in a freeDB record. */
typedef struct MDBX_page {
union {
pgno_t mp_pgno; /* page number */
uint64_t mp_validator; /* checksum of page content or a txnid during
* which the page has been updated */
struct MDBX_page *mp_next; /* for in-memory list of freed pages */
};
uint16_t mp_leaf2_ksize; /* key size if this is a LEAF2 page */
@@ -318,6 +330,7 @@ typedef struct MDBX_page {
};
uint32_t mp_pages; /* number of overflow pages */
};
pgno_t mp_pgno; /* page number */
/* dynamic size */
union {
@@ -330,15 +343,19 @@ typedef struct MDBX_page {
/* Size of the page header, excluding dynamic data at the end */
#define PAGEHDRSZ ((unsigned)offsetof(MDBX_page, mp_data))
#pragma pack(pop)
/* The header for the reader table (a memory-mapped lock file). */
typedef struct MDBX_lockinfo {
/* Stamp identifying this as an MDBX file. It must be set to MDBX_MAGIC. */
uint64_t mti_magic;
/* Stamp identifying this as an MDBX file.
* It must be set to MDBX_MAGIC with with MDBX_LOCK_VERSION. */
uint64_t mti_magic_and_version;
/* Format of this lock file. Must be set to MDBX_LOCK_FORMAT. */
uint64_t mti_format;
uint32_t mti_os_and_format;
/* Flags which environment was opened. */
uint32_t mti_envmode;
uint32_t mti_reserved;
volatile uint32_t mti_envmode;
#ifdef MDBX_OSAL_LOCK
MDBX_OSAL_LOCK mti_wmutex;
@@ -355,7 +372,19 @@ typedef struct MDBX_lockinfo {
MDBX_reader __cache_aligned mti_readers[1];
} MDBX_lockinfo;
#pragma pack(pop)
#define MDBX_LOCKINFO_WHOLE_SIZE \
((sizeof(MDBX_lockinfo) + MDBX_CACHELINE_SIZE - 1) & \
~((size_t)MDBX_CACHELINE_SIZE - 1))
/* Lockfile format signature: version, features and field layout */
#define MDBX_LOCK_FORMAT \
((MDBX_OSAL_LOCK_SIGN << 16) + \
(uint16_t)(MDBX_LOCKINFO_WHOLE_SIZE + MDBX_CACHELINE_SIZE - 1))
#define MDBX_DATA_MAGIC ((MDBX_MAGIC << 8) + MDBX_DATA_VERSION)
#define MDBX_LOCK_MAGIC ((MDBX_MAGIC << 8) + MDBX_LOCK_VERSION)
/*----------------------------------------------------------------------------*/
/* Two kind lists of pages (aka IDL) */
@@ -574,16 +603,6 @@ typedef struct MDBX_pgstate {
txnid_t mf_pglast; /* ID of last used record, or 0 if !mf_pghead */
} MDBX_pgstate;
#define MDBX_LOCKINFO_WHOLE_SIZE \
((sizeof(MDBX_lockinfo) + MDBX_CACHELINE_SIZE - 1) & \
~((size_t)MDBX_CACHELINE_SIZE - 1))
/* Lockfile format signature: version, features and field layout */
#define MDBX_LOCK_FORMAT \
(((uint64_t)(MDBX_OSAL_LOCK_SIGN) << 32) + \
((MDBX_LOCKINFO_WHOLE_SIZE + MDBX_CACHELINE_SIZE - 1) << 16) + \
(MDBX_LOCK_VERSION) /* Flags which describe functionality */)
/* The database environment. */
struct MDBX_env {
#define MDBX_ME_SIGNATURE (0x9A899641)