Data Structures | |
struct | MDB_page |
struct | MDB_node |
struct | MDB_db |
struct | MDB_meta |
union | MDB_metabuf |
struct | MDB_dbx |
struct | MDB_txn |
Opaque structure for a transaction handle. More... | |
struct | MDB_cursor |
Opaque structure for navigating through a database. More... | |
struct | MDB_xcursor |
struct | MDB_pgstate |
struct | MDB_env |
Opaque structure for a database environment. More... | |
struct | MDB_ntxn |
struct | mdb_copy |
Modules | |
ID List Management | |
Compatibility Macros | |
Debug Macros | |
Reader Lock Table | |
Page Flags | |
Node Flags | |
Transaction DB Flags | |
Transaction Flags | |
Cursor Flags | |
Defines | |
#define | LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex)) |
#define | mdb_mutex_failed(env, mutex, rc) (rc) |
#define | MDB_DSYNC O_SYNC |
#define | MDB_FDATASYNC fdatasync |
#define | MDB_MSYNC(addr, len, flags) msync(addr,len,flags) |
#define | MS_SYNC 1 |
#define | MS_ASYNC 0 |
#define | MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000) |
The maximum size of a database page. | |
#define | MDB_MINKEYS 2 |
#define | MDB_MAGIC 0xBEEFC0DE |
#define | MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1) |
#define | MDB_LOCK_VERSION 1 |
#define | MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511) |
The max size of a key we can write, or 0 for computed max. | |
#define | ENV_MAXKEY(env) (MDB_MAXKEYSIZE) |
#define | MAXDATASIZE 0xffffffffUL |
The maximum size of a data item. | |
#define | DKBUF |
#define | DKEY(x) 0 |
#define | P_INVALID (~(pgno_t)0) |
#define | F_ISSET(w, f) (((w) & (f)) == (f)) |
#define | EVEN(n) (((n) + 1U) & -2) |
#define | DEFAULT_MAPSIZE 1048576 |
#define | PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs)) |
#define | METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ)) |
#define | PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0) |
#define | NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1) |
#define | SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower) |
#define | PAGEFILL(env, p) |
#define | FILL_THRESHOLD 250 |
#define | IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF) |
#define | IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2) |
#define | IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH) |
#define | IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW) |
#define | IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP) |
#define | OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1) |
#define | NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2)) |
#define | NODESIZE offsetof(MDB_node, mn_data) |
#define | PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0) |
#define | INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size)) |
#define | LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size) |
#define | NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE)) |
#define | NODEKEY(node) (void *)((node)->mn_data) |
#define | NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize) |
#define | NODEPGNO(node) |
#define | SETPGNO(node, pgno) |
#define | NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16)) |
#define | SETDSZ(node, size) |
#define | NODEKSZ(node) ((node)->mn_ksize) |
#define | COPY_PGNO(dst, src) |
#define | LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks))) |
#define | MDB_GET_KEY(node, keyptr) |
#define | MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); } |
#define | MDB_VALID 0x8000 |
#define | PERSISTENT_FLAGS (0xffff & ~(MDB_VALID)) |
#define | VALID_FLAGS |
#define | FREE_DBI 0 |
#define | MAIN_DBI 1 |
#define | CORE_DBS 2 |
#define | NUM_METAS 2 |
#define | CURSOR_STACK 32 |
#define | MDB_COMMIT_PAGES 64 |
#define | MAX_WRITE (0x40000000U >> (sizeof(ssize_t) == 4)) |
#define | TXN_DBI_EXIST(txn, dbi, validity) ((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity))) |
#define | TXN_DBI_CHANGED(txn, dbi) ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi]) |
#define | MDB_END_NAMES |
#define | MDB_END_OPMASK 0x0F |
#define | MDB_END_UPDATE 0x10 |
#define | MDB_END_FREE 0x20 |
#define | MDB_END_SLOT MDB_NOTLS |
#define | MDB_PS_MODIFY 1 |
#define | MDB_PS_ROOTONLY 2 |
#define | MDB_PS_FIRST 4 |
#define | MDB_PS_LAST 8 |
#define | MDB_SPLIT_REPLACE MDB_APPENDDUP |
#define | mdb_env_close0(env, excl) mdb_env_close1(env) |
Typedefs | |
typedef MDB_ID | pgno_t |
typedef MDB_ID | txnid_t |
typedef uint16_t | indx_t |
typedef unsigned long long | mdb_hash_t |
Enumerations | |
enum | { MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET, MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD } |
enum | Pidlock_op { Pidset = F_SETLK, Pidcheck = F_GETLK, Pidset = F_SETLK, Pidcheck = F_GETLK } |
enum | Pidlock_op { Pidset = F_SETLK, Pidcheck = F_GETLK, Pidset = F_SETLK, Pidcheck = F_GETLK } |
Functions | |
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 void | mdb_txn_end (MDB_txn *txn, unsigned mode) |
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) |
static int | mdb_page_search (MDB_cursor *mc, MDB_val *key, int flags) |
static int | mdb_page_merge (MDB_cursor *csrc, MDB_cursor *cdst) |
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 MDB_meta * | mdb_env_pick_meta (const MDB_env *env) |
static int | mdb_env_write_meta (MDB_txn *txn) |
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, int fromleft) |
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 void | mdb_xcursor_init2 (MDB_cursor *mc, MDB_xcursor *src_mx, int force) |
static int | mdb_drop0 (MDB_cursor *mc, int subs) |
static void | mdb_default_cmp (MDB_txn *txn, MDB_dbi dbi) |
static int | mdb_reader_check0 (MDB_env *env, int rlocked, int *dead) |
static int | utf8_to_utf16 (const char *src, int srcsize, wchar_t **dst, int *dstsize) |
char *ESECT | mdb_version (int *major, int *minor, int *patch) |
Return the LMDB library version information. | |
char * | mdb_strerror (int err) |
Return a string describing a given error code. | |
static void ESECT | mdb_assert_fail (MDB_env *env, const char *expr_txt, const char *func, const char *file, int line) |
static pgno_t | mdb_dbg_pgno (MDB_page *mp) |
char * | mdb_dkey (MDB_val *key, char *buf) |
static const char * | mdb_leafnode_type (MDB_node *n) |
void | mdb_page_list (MDB_page *mp) |
void | mdb_cursor_chk (MDB_cursor *mc) |
static void | mdb_audit (MDB_txn *txn) |
int | mdb_cmp (MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) |
Compare two data items according to a particular database. | |
int | mdb_dcmp (MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) |
Compare two data items according to a particular database. | |
static MDB_page * | mdb_page_malloc (MDB_txn *txn, unsigned num) |
static void | mdb_page_free (MDB_env *env, MDB_page *mp) |
static void | mdb_dpage_free (MDB_env *env, MDB_page *dp) |
static void | mdb_dlist_free (MDB_txn *txn) |
static int | mdb_page_loose (MDB_cursor *mc, MDB_page *mp) |
static int | mdb_pages_xkeep (MDB_cursor *mc, unsigned pflags, int all) |
static int | mdb_page_flush (MDB_txn *txn, int keep) |
static int | mdb_page_spill (MDB_cursor *m0, MDB_val *key, MDB_val *data) |
static txnid_t | mdb_find_oldest (MDB_txn *txn) |
static void | mdb_page_dirty (MDB_txn *txn, MDB_page *mp) |
static void | mdb_page_copy (MDB_page *dst, MDB_page *src, unsigned int psize) |
static int | mdb_page_unspill (MDB_txn *txn, MDB_page *mp, MDB_page **ret) |
int | mdb_env_sync (MDB_env *env, int force) |
Flush the data buffers to disk. | |
static int | mdb_cursor_shadow (MDB_txn *src, MDB_txn *dst) |
static void | mdb_cursors_close (MDB_txn *txn, unsigned merge) |
static int | mdb_reader_pid (MDB_env *env, enum Pidlock_op op, MDB_PID_T pid) |
static int | mdb_txn_renew0 (MDB_txn *txn) |
int | mdb_txn_renew (MDB_txn *txn) |
Renew a read-only transaction. | |
int | mdb_txn_begin (MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret) |
Create a transaction for use with the environment. | |
MDB_env * | mdb_txn_env (MDB_txn *txn) |
Returns the transaction's MDB_env. | |
size_t | mdb_txn_id (MDB_txn *txn) |
Return the transaction's ID. | |
static void | mdb_dbis_update (MDB_txn *txn, int keep) |
void | mdb_txn_reset (MDB_txn *txn) |
Reset a read-only transaction. | |
void | mdb_txn_abort (MDB_txn *txn) |
Abandon all the operations of the transaction instead of saving them. | |
static int | mdb_freelist_save (MDB_txn *txn) |
int | mdb_txn_commit (MDB_txn *txn) |
Commit all the operations of a transaction into the database. | |
static void ESECT | mdb_env_init_meta0 (MDB_env *env, MDB_meta *meta) |
static int ESECT | mdb_env_init_meta (MDB_env *env, MDB_meta *meta) |
int ESECT | mdb_env_create (MDB_env **env) |
Create an LMDB environment handle. | |
static int ESECT | mdb_env_map (MDB_env *env, void *addr) |
int ESECT | mdb_env_set_mapsize (MDB_env *env, size_t size) |
Set the size of the memory map to use for this environment. | |
int ESECT | mdb_env_set_maxdbs (MDB_env *env, MDB_dbi dbs) |
Set the maximum number of named databases for the environment. | |
int ESECT | mdb_env_set_maxreaders (MDB_env *env, unsigned int readers) |
Set the maximum number of threads/reader slots for the environment. | |
int ESECT | mdb_env_get_maxreaders (MDB_env *env, unsigned int *readers) |
Get the maximum number of threads/reader slots for the environment. | |
static int ESECT | mdb_fsize (HANDLE fd, size_t *size) |
static int ESECT | mdb_env_open2 (MDB_env *env) |
static void | mdb_env_reader_dest (void *ptr) |
static void NTAPI | mdb_tls_callback (PVOID module, DWORD reason, PVOID ptr) |
const PIMAGE_TLS_CALLBACK mdb_tls_cbp | __attribute__ ((section(".CRT$XLB"))) = mdb_tls_callback |
static int ESECT | mdb_env_share_locks (MDB_env *env, int *excl) |
static int ESECT | mdb_env_excl_lock (MDB_env *env, int *excl) |
static mdb_hash_t | mdb_hash_val (MDB_val *val, mdb_hash_t hval) |
static void ESECT | mdb_pack85 (unsigned long l, char *out) |
static void ESECT | mdb_hash_enc (MDB_val *val, char *encbuf) |
static int ESECT | mdb_env_setup_locks (MDB_env *env, char *lpath, int mode, int *excl) |
int ESECT | mdb_env_open (MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode) |
Open an environment handle. | |
void ESECT | mdb_env_close (MDB_env *env) |
Close the environment and release the memory map. | |
static int | mdb_cmp_long (const MDB_val *a, const MDB_val *b) |
static int | mdb_cmp_int (const MDB_val *a, const MDB_val *b) |
static int | mdb_cmp_cint (const MDB_val *a, const MDB_val *b) |
static int | mdb_cmp_memn (const MDB_val *a, const MDB_val *b) |
static int | mdb_cmp_memnr (const MDB_val *a, const MDB_val *b) |
static void | mdb_cursor_adjust (MDB_cursor *mc, func) |
static int | mdb_page_search_lowest (MDB_cursor *mc) |
static int | mdb_ovpage_free (MDB_cursor *mc, MDB_page *mp) |
int | mdb_get (MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) |
Get items from a database. | |
int | mdb_cursor_get (MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) |
Retrieve by cursor. | |
static int | mdb_cursor_touch (MDB_cursor *mc) |
int | mdb_cursor_put (MDB_cursor *mc, MDB_val *key, MDB_val *data, unsigned int flags) |
Store by cursor. | |
int | mdb_cursor_del (MDB_cursor *mc, unsigned int flags) |
Delete current key/data pair. | |
int | mdb_cursor_open (MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret) |
Create a cursor handle. | |
int | mdb_cursor_renew (MDB_txn *txn, MDB_cursor *mc) |
Renew a cursor handle. | |
int | mdb_cursor_count (MDB_cursor *mc, size_t *countp) |
Return count of duplicates for current key. | |
void | mdb_cursor_close (MDB_cursor *mc) |
Close a cursor handle. | |
MDB_txn * | mdb_cursor_txn (MDB_cursor *mc) |
Return the cursor's transaction handle. | |
MDB_dbi | mdb_cursor_dbi (MDB_cursor *mc) |
Return the cursor's database handle. | |
static void | mdb_cursor_copy (const MDB_cursor *csrc, MDB_cursor *cdst) |
int | mdb_del (MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) |
Delete items from a database. | |
int | mdb_put (MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned int flags) |
Store items into a database. | |
static THREAD_RET ESECT CALL_CONV | mdb_env_copythr (void *arg) |
static int ESECT | mdb_env_cthr_toggle (mdb_copy *my, int st) |
static int ESECT | mdb_env_cwalk (mdb_copy *my, pgno_t *pg, int flags) |
static int ESECT | mdb_env_copyfd1 (MDB_env *env, HANDLE fd) |
static int ESECT | mdb_env_copyfd0 (MDB_env *env, HANDLE fd) |
int ESECT | mdb_env_copyfd2 (MDB_env *env, HANDLE fd, unsigned int flags) |
int ESECT | mdb_env_copyfd (MDB_env *env, HANDLE fd) |
int ESECT | mdb_env_copy2 (MDB_env *env, const char *path, unsigned int flags) |
Copy an LMDB environment to the specified path, with options. | |
int ESECT | mdb_env_copy (MDB_env *env, const char *path) |
Copy an LMDB environment to the specified path. | |
int ESECT | mdb_env_set_flags (MDB_env *env, unsigned int flag, int onoff) |
Set environment flags. | |
int ESECT | mdb_env_get_flags (MDB_env *env, unsigned int *arg) |
Get environment flags. | |
int ESECT | mdb_env_set_userctx (MDB_env *env, void *ctx) |
Set application information associated with the MDB_env. | |
void *ESECT | mdb_env_get_userctx (MDB_env *env) |
Get the application information associated with the MDB_env. | |
int ESECT | mdb_env_set_assert (MDB_env *env, MDB_assert_func *func) |
int ESECT | mdb_env_get_path (MDB_env *env, const char **arg) |
Return the path that was used in mdb_env_open(). | |
int ESECT | mdb_env_get_fd (MDB_env *env, mdb_filehandle_t *arg) |
Return the filedescriptor for the given environment. | |
static int ESECT | mdb_stat0 (MDB_env *env, MDB_db *db, MDB_stat *arg) |
int ESECT | mdb_env_stat (MDB_env *env, MDB_stat *arg) |
Return statistics about the LMDB environment. | |
int ESECT | mdb_env_info (MDB_env *env, MDB_envinfo *arg) |
Return information about the LMDB environment. | |
int | mdb_dbi_open (MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi) |
Open a database in the environment. | |
int ESECT | mdb_stat (MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg) |
Retrieve statistics for a database. | |
void | mdb_dbi_close (MDB_env *env, MDB_dbi dbi) |
Close a database handle. Normally unnecessary. Use with care:. | |
int | mdb_dbi_flags (MDB_txn *txn, MDB_dbi dbi, unsigned int *flags) |
Retrieve the DB flags for a database handle. | |
int | mdb_drop (MDB_txn *txn, MDB_dbi dbi, int del) |
Empty or delete+close a database. | |
int | mdb_set_compare (MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) |
Set a custom key comparison function for a database. | |
int | mdb_set_dupsort (MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) |
Set a custom data comparison function for a MDB_DUPSORT database. | |
int | mdb_set_relfunc (MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel) |
Set a relocation function for a MDB_FIXEDMAP database. | |
int | mdb_set_relctx (MDB_txn *txn, MDB_dbi dbi, void *ctx) |
Set a context pointer for a MDB_FIXEDMAP database's relocation function. | |
int ESECT | mdb_env_get_maxkeysize (MDB_env *env) |
Get the maximum size of keys and MDB_DUPSORT data we can write. | |
int ESECT | mdb_reader_list (MDB_env *env, MDB_msg_func *func, void *ctx) |
Dump the entries in the reader lock table. | |
static int ESECT | mdb_pid_insert (MDB_PID_T *ids, MDB_PID_T pid) |
int ESECT | mdb_reader_check (MDB_env *env, int *dead) |
Check for stale entries in the reader lock table. | |
static int ESECT | mdb_mutex_failed (MDB_env *env, mdb_mutexref_t mutex, int rc) |
Variables | |
static SECURITY_DESCRIPTOR | mdb_null_sd |
static SECURITY_ATTRIBUTES | mdb_all_sa |
static int | mdb_sec_inited |
static char *const | mdb_errstr [] |
static pthread_key_t | mdb_tls_keys [MAX_TLS_KEYS] |
static int | mdb_tls_nkeys |
const PIMAGE_TLS_CALLBACK | mdb_tls_cbp = mdb_tls_callback |
static const char | mdb_a85 [] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~" |
#define MDB_DSYNC O_SYNC |
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.
#define MDB_FDATASYNC fdatasync |
Function for flushing the data of a file. Define this to fsync if fdatasync() is not supported.
#define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000) |
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 MDB_MINKEYS 2 |
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_MAGIC 0xBEEFC0DE |
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_DATA_VERSION ((MDB_DEVEL) ? 999 : 1) |
The version number for a database's datafile format.
#define MDB_LOCK_VERSION 1 |
The version number for a database's lockfile format.
#define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511) |
The max size of a key we can write, or 0 for computed max.
This macro should normally be left alone or set to 0. Note that a database with big keys or dupsort data cannot be reliably modified by a liblmdb which uses a smaller max. The default is 511 for backwards compat, or 0 when MDB_DEVEL.
Other values are allowed, for backwards compat. However: A value bigger than the computed max can break if you do not know what you are doing, and liblmdb <= 0.9.10 can break when modifying a DB with keys/dupsort data bigger than its max.
Data items in an MDB_DUPSORT database are also limited to this size, since they're actually keys of a sub-DB. Keys and MDB_DUPSORT data items must fit on a node in a regular page.
#define ENV_MAXKEY | ( | env | ) | (MDB_MAXKEYSIZE) |
The maximum size of a key we can write to the environment.
#define MAXDATASIZE 0xffffffffUL |
The maximum size of a data item.
We only store a 32 bit value for node sizes.
#define P_INVALID (~(pgno_t)0) |
An invalid page number. Mainly used to denote an empty tree.
#define F_ISSET | ( | w, | |||
f | ) | (((w) & (f)) == (f)) |
Test if the flags f are set in a flag word w.
#define EVEN | ( | n | ) | (((n) + 1U) & -2) |
Round n up to an even number.
#define DEFAULT_MAPSIZE 1048576 |
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 PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs)) |
Size of the page header, excluding dynamic data at the end
#define METADATA | ( | p | ) | ((void *)((char *)(p) + PAGEHDRSZ)) |
Address of first usable data byte in a page, after the header
#define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0) |
ITS#7713, change PAGEBASE to handle 65536 byte pages
#define NUMKEYS | ( | p | ) | (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1) |
Number of nodes on a page
#define SIZELEFT | ( | p | ) | (indx_t)((p)->mp_upper - (p)->mp_lower) |
The amount of space remaining in the page
#define PAGEFILL | ( | env, | |||
p | ) |
#define FILL_THRESHOLD 250 |
The minimum page fill factor, in tenths of a percent. Pages emptier than this are candidates for merging.
#define IS_LEAF | ( | p | ) | F_ISSET((p)->mp_flags, P_LEAF) |
Test if a page is a leaf page
#define IS_LEAF2 | ( | p | ) | F_ISSET((p)->mp_flags, P_LEAF2) |
Test if a page is a LEAF2 page
#define IS_BRANCH | ( | p | ) | F_ISSET((p)->mp_flags, P_BRANCH) |
Test if a page is a branch page
#define IS_OVERFLOW | ( | p | ) | F_ISSET((p)->mp_flags, P_OVERFLOW) |
Test if a page is an overflow page
#define IS_SUBP | ( | p | ) | F_ISSET((p)->mp_flags, P_SUBP) |
Test if a page is a sub page
#define OVPAGES | ( | size, | |||
psize | ) | ((PAGEHDRSZ-1 + (size)) / (psize) + 1) |
The number of overflow pages needed to store the given size.
#define NODESIZE offsetof(MDB_node, mn_data) |
Size of the node header, excluding dynamic data at the end
#define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0) |
Bit position of top word in page number, for shifting mn_flags
#define INDXSIZE | ( | k | ) | (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size)) |
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 LEAFSIZE | ( | k, | |||
d | ) | (NODESIZE + (k)->mv_size + (d)->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 NODEPTR | ( | p, | |||
i | ) | ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE)) |
Address of node i in page p
#define NODEKEY | ( | node | ) | (void *)((node)->mn_data) |
Address of the key for the node
#define NODEDATA | ( | node | ) | (void *)((char *)(node)->mn_data + (node)->mn_ksize) |
Address of the data for a node
#define NODEPGNO | ( | node | ) |
((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \ (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
Get the page number pointed to by 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)
Set the page number in a branch node
#define NODEDSZ | ( | node | ) | ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16)) |
Get the size of the data in a leaf node
#define SETDSZ | ( | node, | |||
size | ) |
do { \ (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
Set the size of the data for a leaf node
#define NODEKSZ | ( | node | ) | ((node)->mn_ksize) |
The size of a key in a node
#define COPY_PGNO | ( | dst, | |||
src | ) |
do { \ unsigned short *s, *d; \ s = (unsigned short *)&(src); \ d = (unsigned short *)&(dst); \ *d++ = *s++; \ *d = *s; \ } while (0)
Copy a page number from src to dst
#define LEAF2KEY | ( | p, | |||
i, | |||||
ks | ) | ((char *)(p) + PAGEHDRSZ + ((i)*(ks))) |
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 MDB_GET_KEY | ( | node, | |||
keyptr | ) |
#define MDB_GET_KEY2 | ( | node, | |||
key | ) | { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); } |
Set the node's key into key.
#define MDB_VALID 0x8000 |
mdb_dbi_open flags DB handle is valid, for me_dbflags
#define VALID_FLAGS |
#define FREE_DBI 0 |
Handle for the DB used to track free pages.
#define MAIN_DBI 1 |
Handle for the default DB.
#define CORE_DBS 2 |
Number of DBs in metapage (free and main) - also hardcoded elsewhere
#define NUM_METAS 2 |
Number of meta pages - also hardcoded elsewhere
#define CURSOR_STACK 32 |
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 MDB_COMMIT_PAGES 64 |
max number of pages to commit in one writev() call
#define MAX_WRITE (0x40000000U >> (sizeof(ssize_t) == 4)) |
max bytes to write in one call
#define TXN_DBI_EXIST | ( | txn, | |||
dbi, | |||||
validity | ) | ((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity))) |
Check txn and dbi arguments to a function
#define TXN_DBI_CHANGED | ( | txn, | |||
dbi | ) | ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi]) |
Check for misused dbi handles
#define MDB_END_NAMES |
{"committed", "empty-commit", "abort", "reset", \ "reset-tmp", "fail-begin", "fail-beginchild"}
#define MDB_END_OPMASK 0x0F |
mask for mdb_txn_end() operation number
#define MDB_END_UPDATE 0x10 |
update env state (DBIs)
#define MDB_END_FREE 0x20 |
free txn unless it is MDB_env.me_txn0
#define MDB_END_SLOT MDB_NOTLS |
release any reader slot if MDB_NOTLS
#define MDB_SPLIT_REPLACE MDB_APPENDDUP |
newkey is not new
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.
A transaction ID. See struct MDB_txn.mt_txnid for details.
typedef uint16_t indx_t |
Used for offsets within a single page. Since memory pages are typically 4 or 8KB in size, 12-13 bits, this is plenty.
static int mdb_page_alloc | ( | MDB_cursor * | mc, | |
int | num, | |||
MDB_page ** | mp | |||
) | [static] |
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.
[in] | mc | cursor A cursor handle identifying the transaction and database for which we are allocating. |
[in] | num | the number of pages to allocate. |
[out] | mp | Address of the allocated page(s). Requests for multiple pages will always be satisfied by a single contiguous chunk of memory. |
static int mdb_page_new | ( | MDB_cursor * | mc, | |
uint32_t | flags, | |||
int | num, | |||
MDB_page ** | mp | |||
) | [static] |
Allocate and initialize new pages for a database.
[in] | mc | a cursor on the database being added to. |
[in] | flags | flags defining what type of page is being allocated. |
[in] | num | the number of pages to allocate. This is usually 1, unless allocating overflow pages for a large record. |
[out] | mp | Address of a page, or NULL on failure. |
static int mdb_page_touch | ( | MDB_cursor * | mc | ) | [static] |
Touch a page: make it dirty and re-insert into tree with updated pgno.
[in] | mc | cursor pointing to the page to be touched |
static void mdb_txn_end | ( | MDB_txn * | txn, | |
unsigned | mode | |||
) | [static] |
End a transaction, except successful commit of a nested transaction. May be called twice for readonly txns: First reset it, then abort.
[in] | txn | the transaction handle to end |
[in] | mode | why and how to end the transaction |
Find the address of the page corresponding to a given page number.
[in] | txn | the transaction for this access. |
[in] | pgno | the page number for the page to retrieve. |
[out] | ret | address of a pointer where the page's address will be stored. |
[out] | lvl | dirty_list inheritance level of found page. 1=current txn, 0=mapped page. |
static int mdb_page_search_root | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
int | flags | |||
) | [static] |
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 | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
int | flags | |||
) | [static] |
Search for the page a given key should be in. Push it and its parent pages on the cursor stack.
[in,out] | mc | the cursor for this operation. |
[in] | key | the key to search for, or NULL for first/last page. |
[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. |
static int mdb_page_merge | ( | MDB_cursor * | csrc, | |
MDB_cursor * | cdst | |||
) | [static] |
Merge one page into another. The nodes from the page pointed to by csrc will be copied to the page pointed to by cdst and then the csrc page will be freed.
[in] | csrc | Cursor pointing to the source page. |
[in] | cdst | Cursor pointing to the destination page. |
static int mdb_page_split | ( | MDB_cursor * | mc, | |
MDB_val * | newkey, | |||
MDB_val * | newdata, | |||
pgno_t | newpgno, | |||
unsigned int | nflags | |||
) | [static] |
Split a page and insert a new node.
[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. |
[in] | newkey | The key for the newly inserted node. |
[in] | newdata | The data for the newly inserted node. |
[in] | newpgno | The page number, if the new node is a branch node. |
[in] | nflags | The NODE_ADD_FLAGS for the new node. |
Read the environment parameters of a DB environment before mapping it into memory.
[in] | env | the environment handle |
[out] | meta | address of where to store the meta information |
Check both meta pages to see which one is newer.
[in] | env | the environment handle |
static int mdb_env_write_meta | ( | MDB_txn * | txn | ) | [static] |
Update the environment info to commit a transaction.
[in] | txn | the transaction that's being committed |
static void ESECT mdb_env_close0 | ( | MDB_env * | env, | |
int | excl | |||
) | [static] |
Destroy resources from mdb_env_open(), clear our readers & DBIs
static MDB_node * mdb_node_search | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
int * | exactp | |||
) | [static] |
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 int mdb_node_add | ( | MDB_cursor * | mc, | |
indx_t | indx, | |||
MDB_val * | key, | |||
MDB_val * | data, | |||
pgno_t | pgno, | |||
unsigned int | flags | |||
) | [static] |
Add a node to the page pointed to by the cursor.
[in] | mc | The cursor for this operation. |
[in] | indx | The index on the page where the new node should be added. |
[in] | key | The key for the new node. |
[in] | data | The data for the new node, if any. |
[in] | pgno | The page number, if adding a branch node. |
[in] | flags | Flags for the node. |
static void mdb_node_del | ( | MDB_cursor * | mc, | |
int | ksize | |||
) | [static] |
Delete the specified node from a page.
[in] | mc | Cursor pointing to the node to delete. |
[in] | ksize | The size of a node. Only used if the page is part of a MDB_DUPFIXED database. |
Compact the main page after deleting a node on a subpage.
[in] | mp | The main page to operate on. |
[in] | indx | The index of the subpage on the main page. |
static int mdb_node_move | ( | MDB_cursor * | csrc, | |
MDB_cursor * | cdst, | |||
int | fromleft | |||
) | [static] |
Move a node from csrc to cdst.
Return the data associated with a given node.
[in] | txn | The transaction for this operation. |
[in] | leaf | The node being read. |
[out] | data | Updated to point to the node's data. |
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.
[in] | env | The environment handle. |
[in] | key | The key for the node. |
[in] | data | The data for the node. |
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.
[in] | env | The environment handle. |
[in] | key | The key for the node. |
static int mdb_rebalance | ( | MDB_cursor * | mc | ) | [static] |
Rebalance the tree after a delete operation.
[in] | mc | Cursor pointing to the page where rebalancing should begin. |
static int mdb_update_key | ( | MDB_cursor * | mc, | |
MDB_val * | key | |||
) | [static] |
Replace the key for a branch node with a new key.
[in] | mc | Cursor pointing to the node to operate on. |
[in] | key | The new key to use. |
static void mdb_cursor_pop | ( | MDB_cursor * | mc | ) | [static] |
Pop a page off the top of the cursor's stack.
static int mdb_cursor_push | ( | MDB_cursor * | mc, | |
MDB_page * | mp | |||
) | [static] |
Push a page onto the top of the cursor's stack.
static int mdb_cursor_del0 | ( | MDB_cursor * | mc | ) | [static] |
Complete a delete operation started by mdb_cursor_del().
static int mdb_cursor_sibling | ( | MDB_cursor * | mc, | |
int | move_right | |||
) | [static] |
Find a sibling for a page. Replaces the page at the top of the cursor's stack with the specified sibling, if one exists.
[in] | mc | The cursor for this operation. |
[in] | move_right | Non-zero if the right sibling is requested, otherwise the left sibling. |
static int mdb_cursor_next | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
MDB_val * | data, | |||
MDB_cursor_op | op | |||
) | [static] |
Move the cursor to the next data item.
static int mdb_cursor_prev | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
MDB_val * | data, | |||
MDB_cursor_op | op | |||
) | [static] |
Move the cursor to the previous data item.
static int mdb_cursor_set | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
MDB_val * | data, | |||
MDB_cursor_op | op, | |||
int * | exactp | |||
) | [static] |
Set the cursor on a specific data item.
static int mdb_cursor_first | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
MDB_val * | data | |||
) | [static] |
Move the cursor to the first item in the database.
static int mdb_cursor_last | ( | MDB_cursor * | mc, | |
MDB_val * | key, | |||
MDB_val * | data | |||
) | [static] |
Move the cursor to the last item in the database.
static void mdb_cursor_init | ( | MDB_cursor * | mc, | |
MDB_txn * | txn, | |||
MDB_dbi | dbi, | |||
MDB_xcursor * | mx | |||
) | [static] |
Initialize a cursor for a given transaction and database.
static void mdb_xcursor_init0 | ( | MDB_cursor * | mc | ) | [static] |
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.
[in] | mc | The main cursor whose sorted-dups cursor is to be initialized. |
static void mdb_xcursor_init1 | ( | MDB_cursor * | mc, | |
MDB_node * | node | |||
) | [static] |
Final setup of a sorted-dups cursor. Sets up the fields that depend on the data from the main cursor.
[in] | mc | The main cursor whose sorted-dups cursor is to be initialized. |
[in] | node | The data containing the MDB_db record for the sorted-dup database. |
static void mdb_xcursor_init2 | ( | MDB_cursor * | mc, | |
MDB_xcursor * | src_mx, | |||
int | new_dupdata | |||
) | [static] |
Fixup a sorted-dups cursor due to underlying update. Sets up some fields that depend on the data from the main cursor. Almost the same as init1, but skips initialization steps if the xcursor had already been used.
[in] | mc | The main cursor whose sorted-dups cursor is to be fixed up. |
[in] | src_mx | The xcursor of an up-to-date cursor. |
[in] | new_dupdata | True if converting from a non-F_DUPDATA item. |
static int mdb_drop0 | ( | MDB_cursor * | mc, | |
int | subs | |||
) | [static] |
Add all the DB's pages to the free list.
[in] | mc | Cursor on the DB to free. |
[in] | subs | non-Zero to check for sub-DBs in this DB. |
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().
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
static int ESECT mdb_reader_check0 | ( | MDB_env * | env, | |
int | rlocked, | |||
int * | dead | |||
) | [static] |
As mdb_reader_check(). rlocked = <caller locked="" the="" reader="" mutex>="">.
char* ESECT mdb_version | ( | int * | major, | |
int * | minor, | |||
int * | patch | |||
) |
Return the LMDB library version information.
Return the library version info.
char* mdb_strerror | ( | int | err | ) |
Return a string describing a given error code.
This function is a superset of the ANSI C X3.159-1989 (ANSI C) strerror(3) function. If the error code is greater than or equal to 0, then the string returned by the system function strerror(3) is returned. If the error code is less than 0, an error string corresponding to the LMDB library error is returned. See Return Codes for a list of LMDB-specific error codes.
[in] | err | The error code |
error message | The description of the error |
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.
Return the page number of mp which may be sub-page, for debug output
char* mdb_dkey | ( | MDB_val * | key, | |
char * | buf | |||
) |
Display a key in hexadecimal and return the address of the result.
[in] | key | the key to display |
[in] | buf | the buffer to write into. Should always be DKBUF. |
void mdb_page_list | ( | MDB_page * | mp | ) |
Display all the keys in the page.
static void mdb_audit | ( | MDB_txn * | txn | ) | [static] |
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.
Compare two data items according to a particular database.
This returns a comparison as if the two data items were keys in the specified database.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | a | The first item to compare |
[in] | b | The second item to compare |
Compare two data items according to a particular database.
This returns a comparison as if the two items were data items of the specified database. The database must have the MDB_DUPSORT flag.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | a | The first item to compare |
[in] | b | The second item to compare |
Allocate memory for a page. Re-use old malloc'd pages first for singletons, otherwise just malloc.
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_dlist_free | ( | MDB_txn * | txn | ) | [static] |
Return all dirty pages to dpage list
static int mdb_page_loose | ( | MDB_cursor * | mc, | |
MDB_page * | mp | |||
) | [static] |
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_pages_xkeep | ( | MDB_cursor * | mc, | |
unsigned | pflags, | |||
int | all | |||
) | [static] |
Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
[in] | mc | A cursor handle for the current operation. |
[in] | pflags | Flags of the pages to update: P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it. |
[in] | all | No shortcuts. Needed except after a full mdb_page_flush(). |
static int mdb_page_flush | ( | MDB_txn * | txn, | |
int | keep | |||
) | [static] |
Flush (some) dirty pages to the map, after clearing their dirty flag.
[in] | txn | the transaction that's being committed |
[in] | keep | number of initial pages in dirty_list to keep dirty. |
static int mdb_page_spill | ( | MDB_cursor * | m0, | |
MDB_val * | key, | |||
MDB_val * | data | |||
) | [static] |
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.
[in] | m0 | cursor A cursor handle identifying the transaction and database for which we are checking space. |
[in] | key | For a put operation, the key being stored. |
[in] | data | For a put operation, the data being stored. |
Find oldest txnid still referenced. Expects txn->mt_txnid > 0.
Add a page to the txn's dirty list
Copy the used portions of a non-overflow page.
[in] | dst | page to copy into |
[in] | src | page to copy from |
[in] | psize | size of a page |
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.
[in] | txn | the transaction handle. |
[in] | mp | the page being referenced. It must not be dirty. |
[out] | ret | the writable page, if any. ret is unchanged if mp wasn't spilled. |
int mdb_env_sync | ( | MDB_env * | env, | |
int | force | |||
) |
Flush the data buffers to disk.
Data is always written to disk when mdb_txn_commit() is called, but the operating system may keep it buffered. LMDB always flushes the OS buffers upon commit as well, unless the environment was opened with MDB_NOSYNC or in part MDB_NOMETASYNC. This call is not valid if the environment was opened with MDB_RDONLY.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | force | If non-zero, force a synchronous flush. Otherwise if the environment has the MDB_NOSYNC flag set the flushes will be omitted, and with MDB_MAPASYNC they will be asynchronous. |
Back up parent txn's cursors, then grab the originals for tracking
static void mdb_cursors_close | ( | MDB_txn * | txn, | |
unsigned | merge | |||
) | [static] |
Close this write txn's cursors, give parent txn's cursors back to parent.
[in] | txn | the transaction handle. |
[in] | merge | true to keep changes to parent cursors, false to revert. |
static int mdb_reader_pid | ( | MDB_env * | env, | |
enum Pidlock_op | op, | |||
MDB_PID_T | pid | |||
) | [static] |
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_txn_renew0 | ( | MDB_txn * | txn | ) | [static] |
Common code for mdb_txn_begin() and mdb_txn_renew().
[in] | txn | the transaction handle to initialize |
int mdb_txn_renew | ( | MDB_txn * | txn | ) |
Renew a read-only transaction.
This acquires a new reader lock for a transaction handle that had been released by mdb_txn_reset(). It must be called before a reset transaction may be used again.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
Create a transaction for use with the environment.
The transaction handle may be discarded using mdb_txn_abort() or mdb_txn_commit().
[in] | env | An environment handle returned by mdb_env_create() |
[in] | parent | If this parameter is non-NULL, the new transaction will be a nested transaction, with the transaction indicated by parent as its parent. Transactions may be nested to any level. A parent transaction and its cursors may not issue any other operations than mdb_txn_commit and mdb_txn_abort while it has active child transactions. |
[in] | flags | Special options for this transaction. This parameter must be set to 0 or by bitwise OR'ing together one or more of the values described here.
|
[out] | txn | Address where the new MDB_txn handle will be stored |
Returns the transaction's MDB_env.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
size_t mdb_txn_id | ( | MDB_txn * | txn | ) |
Return the transaction's ID.
This returns the identifier associated with this transaction. For a read-only transaction, this corresponds to the snapshot being read; concurrent readers will frequently have the same transaction ID.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
static void mdb_dbis_update | ( | MDB_txn * | txn, | |
int | keep | |||
) | [static] |
Export or close DBI handles opened in this txn.
void mdb_txn_reset | ( | MDB_txn * | txn | ) |
Reset a read-only transaction.
Abort the transaction like mdb_txn_abort(), but keep the transaction handle. mdb_txn_renew() may reuse the handle. This saves allocation overhead if the process will start a new read-only transaction soon, and also locking overhead if MDB_NOTLS is in use. The reader table lock is released, but the table slot stays tied to its thread or MDB_txn. Use mdb_txn_abort() to discard a reset handle, and to free its lock table slot if MDB_NOTLS is in use. Cursors opened within the transaction must not be used again after this call, except with mdb_cursor_renew(). Reader locks generally don't interfere with writers, but they keep old versions of database pages allocated. Thus they prevent the old pages from being reused when writers commit new data, and so under heavy load the database size may grow much more rapidly than otherwise.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
void mdb_txn_abort | ( | MDB_txn * | txn | ) |
Abandon all the operations of the transaction instead of saving them.
The transaction handle is freed. It and its cursors must not be used again after this call, except with mdb_cursor_renew().
[in] | txn | A transaction handle returned by mdb_txn_begin() |
static int mdb_freelist_save | ( | MDB_txn * | txn | ) | [static] |
Save the freelist as of this transaction to the freeDB. This changes the freelist. Keep trying until it stabilizes.
int mdb_txn_commit | ( | MDB_txn * | txn | ) |
Commit all the operations of a transaction into the database.
The transaction handle is freed. It and its cursors must not be used again after this call, except with mdb_cursor_renew().
[in] | txn | A transaction handle returned by mdb_txn_begin() |
Fill in most of the zeroed MDB_meta for an empty database environment
Write the environment parameters of a freshly created DB environment.
[in] | env | the environment handle |
[in] | meta | the MDB_meta to write |
int ESECT mdb_env_create | ( | MDB_env ** | env | ) |
Create an LMDB environment handle.
This function allocates memory for a MDB_env structure. To release the allocated memory and discard the handle, call mdb_env_close(). Before the handle may be used, it must be opened using mdb_env_open(). Various other options may also need to be set before opening the handle, e.g. mdb_env_set_mapsize(), mdb_env_set_maxreaders(), mdb_env_set_maxdbs(), depending on usage requirements.
[out] | env | The address where the new handle will be stored |
int ESECT mdb_env_set_mapsize | ( | MDB_env * | env, | |
size_t | size | |||
) |
Set the size of the memory map to use for this environment.
The size should be a multiple of the OS page size. The default is 10485760 bytes. The size of the memory map is also the maximum size of the database. The value should be chosen as large as possible, to accommodate future growth of the database. This function should be called after mdb_env_create() and before mdb_env_open(). It may be called at later times if no transactions are active in this process. Note that the library does not check for this condition, the caller must ensure it explicitly.
The new size takes effect immediately for the current process but will not be persisted to any others until a write transaction has been committed by the current process. Also, only mapsize increases are persisted into the environment.
If the mapsize is increased by another process, and data has grown beyond the range of the current mapsize, mdb_txn_begin() will return MDB_MAP_RESIZED. This function may be called with a size of zero to adopt the new size.
Any attempt to set a size smaller than the space already consumed by the environment will be silently changed to the current size of the used space.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | size | The size in bytes |
Set the maximum number of named databases for the environment.
This function is only needed if multiple databases will be used in the environment. Simpler applications that use the environment as a single unnamed database can ignore this option. This function may only be called after mdb_env_create() and before mdb_env_open().
Currently a moderate number of slots are cheap but a huge number gets expensive: 7-120 words per transaction, and every mdb_dbi_open() does a linear search of the opened slots.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | dbs | The maximum number of databases |
int ESECT mdb_env_set_maxreaders | ( | MDB_env * | env, | |
unsigned int | readers | |||
) |
Set the maximum number of threads/reader slots for the environment.
This defines the number of slots in the lock table that is used to track readers in the the environment. The default is 126. Starting a read-only transaction normally ties a lock table slot to the current thread until the environment closes or the thread exits. If MDB_NOTLS is in use, mdb_txn_begin() instead ties the slot to the MDB_txn object until it or the MDB_env object is destroyed. This function may only be called after mdb_env_create() and before mdb_env_open().
[in] | env | An environment handle returned by mdb_env_create() |
[in] | readers | The maximum number of reader lock table slots |
int ESECT mdb_env_get_maxreaders | ( | MDB_env * | env, | |
unsigned int * | readers | |||
) |
Get the maximum number of threads/reader slots for the environment.
[in] | env | An environment handle returned by mdb_env_create() |
[out] | readers | Address of an integer to store the number of readers |
static int ESECT mdb_env_open2 | ( | MDB_env * | env | ) | [static] |
Further setup required for opening an LMDB environment
static void mdb_env_reader_dest | ( | void * | ptr | ) | [static] |
Release a reader thread's slot in the reader lock table. This function is called automatically when a thread exits.
[in] | ptr | This points to the slot in the reader lock table. |
static int ESECT mdb_env_share_locks | ( | MDB_env * | env, | |
int * | excl | |||
) | [static] |
Downgrade the exclusive lock on the region back to shared
static int ESECT mdb_env_excl_lock | ( | MDB_env * | env, | |
int * | excl | |||
) | [static] |
Try to get exclusive lock, otherwise shared. Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
static mdb_hash_t mdb_hash_val | ( | MDB_val * | val, | |
mdb_hash_t | hval | |||
) | [static] |
perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
[in] | val | value to hash |
[in] | hval | initial value for hash |
NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the hval arg on the first call.
static int ESECT mdb_env_setup_locks | ( | MDB_env * | env, | |
char * | lpath, | |||
int | mode, | |||
int * | excl | |||
) | [static] |
Open and/or initialize the lock region for the environment.
[in] | env | The LMDB environment. |
[in] | lpath | The pathname of the file used for the lock region. |
[in] | mode | The Unix permissions for the file, if we create it. |
[in,out] | excl | In -1, out lock type: -1 none, 0 shared, 1 exclusive |
int ESECT mdb_env_open | ( | MDB_env * | env, | |
const char * | path, | |||
unsigned int | flags, | |||
mdb_mode_t | mode | |||
) |
Open an environment handle.
If this function fails, mdb_env_close() must be called to discard the MDB_env handle.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | path | The directory in which the database files reside. This directory must already exist and be writable. |
[in] | flags | Special options for this environment. This parameter must be set to 0 or by bitwise OR'ing together one or more of the values described here. Flags set by mdb_env_set_flags() are also used.
|
[in] | mode | The UNIX permissions to set on created files and semaphores. This parameter is ignored on Windows. |
void ESECT mdb_env_close | ( | MDB_env * | env | ) |
Close the environment and release the memory map.
Only a single thread may call this function. All transactions, databases, and cursors must already be closed before calling this function. Attempts to use any such handles after calling this function will cause a SIGSEGV. The environment handle will be freed and must not be used again after this call.
[in] | env | An environment handle returned by mdb_env_create() |
Compare two items pointing at aligned size_t's
Compare two items pointing at aligned unsigned int's.
This is also set as MDB_INTEGERDUP|MDB_DUPFIXED's MDB_dbx.md_dcmp, but mdb_cmp_clong() is called instead if the data type is size_t.
Compare two items pointing at unsigned ints of unknown alignment. Nodes and keys are guaranteed to be 2-byte aligned.
Compare two items lexically
Compare two items in reverse byte order
static int mdb_page_search_lowest | ( | MDB_cursor * | mc | ) | [static] |
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.
Get items from a database.
This function retrieves key/data pairs from the database. The address and length of the data associated with the specified key are returned in the structure to which data refers. If the database supports duplicate keys (MDB_DUPSORT) then the first data item for the key will be returned. Retrieval of other items requires the use of mdb_cursor_get().
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | key | The key to search for in the database |
[out] | data | The data corresponding to the key |
int mdb_cursor_get | ( | MDB_cursor * | cursor, | |
MDB_val * | key, | |||
MDB_val * | data, | |||
MDB_cursor_op | op | |||
) |
Retrieve by cursor.
This function retrieves key/data pairs from the database. The address and length of the key are returned in the object to which key refers (except for the case of the MDB_SET option, in which the key object is unchanged), and the address and length of the data are returned in the object to which data refers. See mdb_get() for restrictions on using the output values.
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
[in,out] | key | The key for a retrieved item |
[in,out] | data | The data of a retrieved item |
[in] | op | A cursor operation MDB_cursor_op |
static int mdb_cursor_touch | ( | MDB_cursor * | mc | ) | [static] |
Touch all the pages in the cursor stack. Set mc_top. Makes sure all the pages are writable, before attempting a write operation.
[in] | mc | The cursor to operate on. |
int mdb_cursor_put | ( | MDB_cursor * | cursor, | |
MDB_val * | key, | |||
MDB_val * | data, | |||
unsigned int | flags | |||
) |
Store by cursor.
This function stores key/data pairs into the database. The cursor is positioned at the new item, or on failure usually near it.
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
[in] | key | The key operated on. |
[in] | data | The data operated on. |
[in] | flags | Options for this operation. This parameter must be set to 0 or one of the values described here.
|
int mdb_cursor_del | ( | MDB_cursor * | cursor, | |
unsigned int | flags | |||
) |
Delete current key/data pair.
This function deletes the key/data pair to which the cursor refers.
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
[in] | flags | Options for this operation. This parameter must be set to 0 or one of the values described here.
|
int mdb_cursor_open | ( | MDB_txn * | txn, | |
MDB_dbi | dbi, | |||
MDB_cursor ** | cursor | |||
) |
Create a cursor handle.
A cursor is associated with a specific transaction and database. A cursor cannot be used when its database handle is closed. Nor when its transaction has ended, except with mdb_cursor_renew(). It can be discarded with mdb_cursor_close(). A cursor in a write-transaction can be closed before its transaction ends, and will otherwise be closed when its transaction ends. A cursor in a read-only transaction must be closed explicitly, before or after its transaction ends. It can be reused with mdb_cursor_renew() before finally closing it.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[out] | cursor | Address where the new MDB_cursor handle will be stored |
int mdb_cursor_renew | ( | MDB_txn * | txn, | |
MDB_cursor * | cursor | |||
) |
Renew a cursor handle.
A cursor is associated with a specific transaction and database. Cursors that are only used in read-only transactions may be re-used, to avoid unnecessary malloc/free overhead. The cursor may be associated with a new read-only transaction, and referencing the same database handle as it was created with. This may be done whether the previous transaction is live or dead.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
int mdb_cursor_count | ( | MDB_cursor * | cursor, | |
size_t * | countp | |||
) |
Return count of duplicates for current key.
This call is only valid on databases that support sorted duplicate data items MDB_DUPSORT.
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
[out] | countp | Address where the count will be stored |
void mdb_cursor_close | ( | MDB_cursor * | cursor | ) |
Close a cursor handle.
The cursor handle will be freed and must not be used again after this call. Its transaction must still be live if it is a write-transaction.
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
MDB_txn* mdb_cursor_txn | ( | MDB_cursor * | cursor | ) |
Return the cursor's transaction handle.
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
MDB_dbi mdb_cursor_dbi | ( | MDB_cursor * | cursor | ) |
Return the cursor's database handle.
[in] | cursor | A cursor handle returned by mdb_cursor_open() |
static void mdb_cursor_copy | ( | const MDB_cursor * | csrc, | |
MDB_cursor * | cdst | |||
) | [static] |
Copy the contents of a cursor.
[in] | csrc | The cursor to copy from. |
[out] | cdst | The cursor to copy to. |
Delete items from a database.
This function removes key/data pairs from the database. If the database does not support sorted duplicate data items (MDB_DUPSORT) the data parameter is ignored. If the database supports sorted duplicates and the data parameter is NULL, all of the duplicate data items for the key will be deleted. Otherwise, if the data parameter is non-NULL only the matching data item will be deleted. This function will return MDB_NOTFOUND if the specified key/data pair is not in the database.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | key | The key to delete from the database |
[in] | data | The data to delete |
Store items into a database.
This function stores key/data pairs in the database. The default behavior is to enter the new key/data pair, replacing any previously existing key if duplicates are disallowed, or adding a duplicate data item if duplicates are allowed (MDB_DUPSORT).
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | key | The key to store in the database |
[in,out] | data | The data to store |
[in] | flags | Special options for this operation. This parameter must be set to 0 or by bitwise OR'ing together one or more of the values described here.
|
static THREAD_RET ESECT CALL_CONV mdb_env_copythr | ( | void * | arg | ) | [static] |
Dedicated writer thread for compacting copy.
static int ESECT mdb_env_cthr_toggle | ( | mdb_copy * | my, | |
int | st | |||
) | [static] |
Tell the writer thread there's a buffer ready to write
Depth-first tree traversal for compacting copy.
static int ESECT mdb_env_copyfd1 | ( | MDB_env * | env, | |
HANDLE | fd | |||
) | [static] |
Copy environment with compaction.
static int ESECT mdb_env_copyfd0 | ( | MDB_env * | env, | |
HANDLE | fd | |||
) | [static] |
Copy environment as-is.
int ESECT mdb_env_copy2 | ( | MDB_env * | env, | |
const char * | path, | |||
unsigned int | flags | |||
) |
Copy an LMDB environment to the specified path, with options.
This function may be used to make a backup of an existing environment. No lockfile is created, since it gets recreated at need.
[in] | env | An environment handle returned by mdb_env_create(). It must have already been opened successfully. |
[in] | path | The directory in which the copy will reside. This directory must already exist and be writable but must otherwise be empty. |
[in] | flags | Special options for this operation. This parameter must be set to 0 or by bitwise OR'ing together one or more of the values described here.
|
int ESECT mdb_env_copy | ( | MDB_env * | env, | |
const char * | path | |||
) |
Copy an LMDB environment to the specified path.
This function may be used to make a backup of an existing environment. No lockfile is created, since it gets recreated at need.
[in] | env | An environment handle returned by mdb_env_create(). It must have already been opened successfully. |
[in] | path | The directory in which the copy will reside. This directory must already exist and be writable but must otherwise be empty. |
int ESECT mdb_env_set_flags | ( | MDB_env * | env, | |
unsigned int | flags, | |||
int | onoff | |||
) |
Set environment flags.
This may be used to set some flags in addition to those from mdb_env_open(), or to unset these flags. If several threads change the flags at the same time, the result is undefined.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | flags | The flags to change, bitwise OR'ed together |
[in] | onoff | A non-zero value sets the flags, zero clears them. |
int ESECT mdb_env_get_flags | ( | MDB_env * | env, | |
unsigned int * | flags | |||
) |
Get environment flags.
[in] | env | An environment handle returned by mdb_env_create() |
[out] | flags | The address of an integer to store the flags |
int ESECT mdb_env_set_userctx | ( | MDB_env * | env, | |
void * | ctx | |||
) |
Set application information associated with the MDB_env.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | ctx | An arbitrary pointer for whatever the application needs. |
void* ESECT mdb_env_get_userctx | ( | MDB_env * | env | ) |
Get the application information associated with the MDB_env.
[in] | env | An environment handle returned by mdb_env_create() |
int ESECT mdb_env_set_assert | ( | MDB_env * | env, | |
MDB_assert_func * | func | |||
) |
Set or reset the assert() callback of the environment. Disabled if liblmdb is buillt with NDEBUG.
[in] | env | An environment handle returned by mdb_env_create(). |
[in] | func | An MDB_assert_func function, or 0. |
int ESECT mdb_env_get_path | ( | MDB_env * | env, | |
const char ** | path | |||
) |
Return the path that was used in mdb_env_open().
[in] | env | An environment handle returned by mdb_env_create() |
[out] | path | Address of a string pointer to contain the path. This is the actual string in the environment, not a copy. It should not be altered in any way. |
int ESECT mdb_env_get_fd | ( | MDB_env * | env, | |
mdb_filehandle_t * | fd | |||
) |
Return the filedescriptor for the given environment.
[in] | env | An environment handle returned by mdb_env_create() |
[out] | fd | Address of a mdb_filehandle_t to contain the descriptor. |
Common code for mdb_stat() and mdb_env_stat().
[in] | env | the environment to operate in. |
[in] | db | the MDB_db record containing the stats to return. |
[out] | arg | the address of an MDB_stat structure to receive the stats. |
Return statistics about the LMDB environment.
[in] | env | An environment handle returned by mdb_env_create() |
[out] | stat | The address of an MDB_stat structure where the statistics will be copied |
int ESECT mdb_env_info | ( | MDB_env * | env, | |
MDB_envinfo * | stat | |||
) |
Return information about the LMDB environment.
[in] | env | An environment handle returned by mdb_env_create() |
[out] | stat | The address of an MDB_envinfo structure where the information will be copied |
Open a database in the environment.
A database handle denotes the name and parameters of a database, independently of whether such a database exists. The database handle may be discarded by calling mdb_dbi_close(). The old database handle is returned if the database was already open. The handle may only be closed once.
The database handle will be private to the current transaction until the transaction is successfully committed. If the transaction is aborted the handle will be closed automatically. After a successful commit the handle will reside in the shared environment, and may be used by other transactions.
This function must not be called from multiple concurrent transactions in the same process. A transaction that uses this function must finish (either commit or abort) before any other transaction in the process may use this function.
To use named databases (with name != NULL), mdb_env_set_maxdbs() must be called before opening the environment. Database names are keys in the unnamed database, and may be read but not written.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | name | The name of the database to open. If only a single database is needed in the environment, this value may be NULL. |
[in] | flags | Special options for this database. This parameter must be set to 0 or by bitwise OR'ing together one or more of the values described here.
|
[out] | dbi | Address where the new MDB_dbi handle will be stored |
Retrieve statistics for a database.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[out] | stat | The address of an MDB_stat structure where the statistics will be copied |
Close a database handle. Normally unnecessary. Use with care:.
This call is not mutex protected. Handles should only be closed by a single thread, and only if no other threads are going to reference the database handle or one of its cursors any further. Do not close a handle if an existing transaction has modified its database. Doing so can cause misbehavior from database corruption to errors like MDB_BAD_VALSIZE (since the DB name is gone).
Closing a database handle is not necessary, but lets mdb_dbi_open() reuse the handle value. Usually it's better to set a bigger mdb_env_set_maxdbs(), unless that value would be large.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
Retrieve the DB flags for a database handle.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[out] | flags | Address where the flags will be returned. |
Empty or delete+close a database.
See mdb_dbi_close() for restrictions about closing the DB handle.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | del | 0 to empty the DB, 1 to delete it from the environment and close the DB handle. |
int mdb_set_compare | ( | MDB_txn * | txn, | |
MDB_dbi | dbi, | |||
MDB_cmp_func * | cmp | |||
) |
Set a custom key comparison function for a database.
The comparison function is called whenever it is necessary to compare a key specified by the application with a key currently stored in the database. If no comparison function is specified, and no special key flags were specified with mdb_dbi_open(), the keys are compared lexically, with shorter keys collating before longer keys.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | cmp | A MDB_cmp_func function |
int mdb_set_dupsort | ( | MDB_txn * | txn, | |
MDB_dbi | dbi, | |||
MDB_cmp_func * | cmp | |||
) |
Set a custom data comparison function for a MDB_DUPSORT database.
This comparison function is called whenever it is necessary to compare a data item specified by the application with a data item currently stored in the database. This function only takes effect if the database was opened with the MDB_DUPSORT flag. If no comparison function is specified, and no special key flags were specified with mdb_dbi_open(), the data items are compared lexically, with shorter items collating before longer items.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | cmp | A MDB_cmp_func function |
int mdb_set_relfunc | ( | MDB_txn * | txn, | |
MDB_dbi | dbi, | |||
MDB_rel_func * | rel | |||
) |
Set a relocation function for a MDB_FIXEDMAP database.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | rel | A MDB_rel_func function |
Set a context pointer for a MDB_FIXEDMAP database's relocation function.
See mdb_set_relfunc and MDB_rel_func for more details.
[in] | txn | A transaction handle returned by mdb_txn_begin() |
[in] | dbi | A database handle returned by mdb_dbi_open() |
[in] | ctx | An arbitrary pointer for whatever the application needs. It will be passed to the callback function set by mdb_set_relfunc as its relctx parameter whenever the callback is invoked. |
int ESECT mdb_env_get_maxkeysize | ( | MDB_env * | env | ) |
Get the maximum size of keys and MDB_DUPSORT data we can write.
Depends on the compile-time constant MDB_MAXKEYSIZE. Default 511. See MDB_val.
[in] | env | An environment handle returned by mdb_env_create() |
int ESECT mdb_reader_list | ( | MDB_env * | env, | |
MDB_msg_func * | func, | |||
void * | ctx | |||
) |
Dump the entries in the reader lock table.
[in] | env | An environment handle returned by mdb_env_create() |
[in] | func | A MDB_msg_func function |
[in] | ctx | Anything the message function needs |
static int ESECT mdb_pid_insert | ( | MDB_PID_T * | ids, | |
MDB_PID_T | pid | |||
) | [static] |
Insert pid into list if not already present. return -1 if already present.
int ESECT mdb_reader_check | ( | MDB_env * | env, | |
int * | dead | |||
) |
Check for stale entries in the reader lock table.
[in] | env | An environment handle returned by mdb_env_create() |
[out] | dead | Number of stale slots that were cleared |
static int ESECT mdb_mutex_failed | ( | MDB_env * | env, | |
mdb_mutexref_t | mutex, | |||
int | rc | |||
) | [static] |
Handle LOCK_MUTEX0() failure. Try to repair the lock file if the mutex owner died.
[in] | env | the environment handle |
[in] | mutex | LOCK_MUTEX0() mutex |
[in] | rc | LOCK_MUTEX0() error (nonzero) |
char* const mdb_errstr[] [static] |
{ "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 or environment had fatal error", "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 must abort, has a child, or is invalid", "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size", "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly", }
Table of descriptions for LMDB Return Codes
const char mdb_a85[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~" [static] |
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.
[in] | str | string to hash |
[out] | encbuf | an array of 11 chars to hold the hash |