.TH "lmdb.h" 3 "Mon Jul 16 2018" "LMDB" \" -*- nroff -*-
.ad l
.nh
.SH NAME
lmdb.h \- Lightning memory-mapped database library\&.  

.SH SYNOPSIS
.br
.PP
\fC#include <sys/types\&.h>\fP
.br

.SS "Data Structures"

.in +1c
.ti -1c
.RI "struct \fBMDB_val\fP"
.br
.RI "Generic structure used for passing keys and data in and out of the database\&. "
.ti -1c
.RI "struct \fBMDB_stat\fP"
.br
.RI "Statistics for a database in the environment\&. "
.ti -1c
.RI "struct \fBMDB_envinfo\fP"
.br
.RI "Information about the environment\&. "
.in -1c
.SS "Macros"

.in +1c
.ti -1c
.RI "#define \fBMDB_VERSION_MAJOR\fP   0"
.br
.ti -1c
.RI "#define \fBMDB_VERSION_MINOR\fP   9"
.br
.ti -1c
.RI "#define \fBMDB_VERSION_PATCH\fP   22"
.br
.ti -1c
.RI "#define \fBMDB_VERINT\fP(a,  b,  c)   (((a) << 24) | ((b) << 16) | (c))"
.br
.ti -1c
.RI "#define \fBMDB_VERSION_FULL\fP   \fBMDB_VERINT\fP(\fBMDB_VERSION_MAJOR\fP,\fBMDB_VERSION_MINOR\fP,\fBMDB_VERSION_PATCH\fP)"
.br
.ti -1c
.RI "#define \fBMDB_VERSION_DATE\fP   'March 21, 2018'"
.br
.ti -1c
.RI "#define \fBMDB_VERSTR\fP(a,  b,  c,  d)   'LMDB ' #a '\&.' #b '\&.' #c ': (' d ')'"
.br
.ti -1c
.RI "#define \fBMDB_VERFOO\fP(a,  b,  c,  d)   \fBMDB_VERSTR\fP(a,b,c,d)"
.br
.ti -1c
.RI "#define \fBMDB_VERSION_STRING\fP   \fBMDB_VERFOO\fP(\fBMDB_VERSION_MAJOR\fP,\fBMDB_VERSION_MINOR\fP,\fBMDB_VERSION_PATCH\fP,\fBMDB_VERSION_DATE\fP)"
.br
.ti -1c
.RI "#define \fBMDB_FIXEDMAP\fP   0x01"
.br
.ti -1c
.RI "#define \fBMDB_NOSUBDIR\fP   0x4000"
.br
.ti -1c
.RI "#define \fBMDB_NOSYNC\fP   0x10000"
.br
.ti -1c
.RI "#define \fBMDB_RDONLY\fP   0x20000"
.br
.ti -1c
.RI "#define \fBMDB_NOMETASYNC\fP   0x40000"
.br
.ti -1c
.RI "#define \fBMDB_WRITEMAP\fP   0x80000"
.br
.ti -1c
.RI "#define \fBMDB_MAPASYNC\fP   0x100000"
.br
.ti -1c
.RI "#define \fBMDB_NOTLS\fP   0x200000"
.br
.ti -1c
.RI "#define \fBMDB_NOLOCK\fP   0x400000"
.br
.ti -1c
.RI "#define \fBMDB_NORDAHEAD\fP   0x800000"
.br
.ti -1c
.RI "#define \fBMDB_NOMEMINIT\fP   0x1000000"
.br
.ti -1c
.RI "#define \fBMDB_REVERSEKEY\fP   0x02"
.br
.ti -1c
.RI "#define \fBMDB_DUPSORT\fP   0x04"
.br
.ti -1c
.RI "#define \fBMDB_INTEGERKEY\fP   0x08"
.br
.ti -1c
.RI "#define \fBMDB_DUPFIXED\fP   0x10"
.br
.ti -1c
.RI "#define \fBMDB_INTEGERDUP\fP   0x20"
.br
.ti -1c
.RI "#define \fBMDB_REVERSEDUP\fP   0x40"
.br
.ti -1c
.RI "#define \fBMDB_CREATE\fP   0x40000"
.br
.ti -1c
.RI "#define \fBMDB_NOOVERWRITE\fP   0x10"
.br
.ti -1c
.RI "#define \fBMDB_NODUPDATA\fP   0x20"
.br
.ti -1c
.RI "#define \fBMDB_CURRENT\fP   0x40"
.br
.ti -1c
.RI "#define \fBMDB_RESERVE\fP   0x10000"
.br
.ti -1c
.RI "#define \fBMDB_APPEND\fP   0x20000"
.br
.ti -1c
.RI "#define \fBMDB_APPENDDUP\fP   0x40000"
.br
.ti -1c
.RI "#define \fBMDB_MULTIPLE\fP   0x80000"
.br
.ti -1c
.RI "#define \fBMDB_CP_COMPACT\fP   0x01"
.br
.ti -1c
.RI "#define \fBMDB_SUCCESS\fP   0"
.br
.ti -1c
.RI "#define \fBMDB_KEYEXIST\fP   (\-30799)"
.br
.ti -1c
.RI "#define \fBMDB_NOTFOUND\fP   (\-30798)"
.br
.ti -1c
.RI "#define \fBMDB_PAGE_NOTFOUND\fP   (\-30797)"
.br
.ti -1c
.RI "#define \fBMDB_CORRUPTED\fP   (\-30796)"
.br
.ti -1c
.RI "#define \fBMDB_PANIC\fP   (\-30795)"
.br
.ti -1c
.RI "#define \fBMDB_VERSION_MISMATCH\fP   (\-30794)"
.br
.ti -1c
.RI "#define \fBMDB_INVALID\fP   (\-30793)"
.br
.ti -1c
.RI "#define \fBMDB_MAP_FULL\fP   (\-30792)"
.br
.ti -1c
.RI "#define \fBMDB_DBS_FULL\fP   (\-30791)"
.br
.ti -1c
.RI "#define \fBMDB_READERS_FULL\fP   (\-30790)"
.br
.ti -1c
.RI "#define \fBMDB_TLS_FULL\fP   (\-30789)"
.br
.ti -1c
.RI "#define \fBMDB_TXN_FULL\fP   (\-30788)"
.br
.ti -1c
.RI "#define \fBMDB_CURSOR_FULL\fP   (\-30787)"
.br
.ti -1c
.RI "#define \fBMDB_PAGE_FULL\fP   (\-30786)"
.br
.ti -1c
.RI "#define \fBMDB_MAP_RESIZED\fP   (\-30785)"
.br
.ti -1c
.RI "#define \fBMDB_INCOMPATIBLE\fP   (\-30784)"
.br
.ti -1c
.RI "#define \fBMDB_BAD_RSLOT\fP   (\-30783)"
.br
.ti -1c
.RI "#define \fBMDB_BAD_TXN\fP   (\-30782)"
.br
.ti -1c
.RI "#define \fBMDB_BAD_VALSIZE\fP   (\-30781)"
.br
.ti -1c
.RI "#define \fBMDB_BAD_DBI\fP   (\-30780)"
.br
.ti -1c
.RI "#define \fBMDB_LAST_ERRCODE\fP   \fBMDB_BAD_DBI\fP"
.br
.ti -1c
.RI "#define \fBmdb_open\fP(txn,  name,  flags,  dbi)   \fBmdb_dbi_open\fP(txn,name,flags,dbi)"
.br
.ti -1c
.RI "#define \fBmdb_close\fP(env,  dbi)   \fBmdb_dbi_close\fP(env,dbi)"
.br
.in -1c
.SS "Typedefs"

.in +1c
.ti -1c
.RI "typedef mode_t \fBmdb_mode_t\fP"
.br
.ti -1c
.RI "typedef int \fBmdb_filehandle_t\fP"
.br
.ti -1c
.RI "typedef unsigned int \fBMDB_dbi\fP"
.br
.RI "A handle for an individual database in the DB environment\&. "
.ti -1c
.RI "typedef int() \fBMDB_cmp_func\fP(const \fBMDB_val\fP *a, const \fBMDB_val\fP *b)"
.br
.RI "A callback function used to compare two keys in a database\&. "
.ti -1c
.RI "typedef void() \fBMDB_rel_func\fP(\fBMDB_val\fP *item, void *oldptr, void *newptr, void *relctx)"
.br
.RI "A callback function used to relocate a position-dependent data item in a fixed-address database\&. "
.ti -1c
.RI "typedef void \fBMDB_assert_func\fP(\fBMDB_env\fP *env, const char *msg)"
.br
.RI "A callback function for most LMDB assert() failures, called before printing the message and aborting\&. "
.ti -1c
.RI "typedef int() \fBMDB_msg_func\fP(const char *msg, void *ctx)"
.br
.RI "A callback function used to print a message from the library\&. "
.in -1c
.SS "Enumerations"

.in +1c
.ti -1c
.RI "enum \fBMDB_cursor_op\fP { \fBMDB_FIRST\fP, \fBMDB_FIRST_DUP\fP, \fBMDB_GET_BOTH\fP, \fBMDB_GET_BOTH_RANGE\fP, \fBMDB_GET_CURRENT\fP, \fBMDB_GET_MULTIPLE\fP, \fBMDB_LAST\fP, \fBMDB_LAST_DUP\fP, \fBMDB_NEXT\fP, \fBMDB_NEXT_DUP\fP, \fBMDB_NEXT_MULTIPLE\fP, \fBMDB_NEXT_NODUP\fP, \fBMDB_PREV\fP, \fBMDB_PREV_DUP\fP, \fBMDB_PREV_NODUP\fP, \fBMDB_SET\fP, \fBMDB_SET_KEY\fP, \fBMDB_SET_RANGE\fP, \fBMDB_PREV_MULTIPLE\fP }
.RI "Cursor Get operations\&. ""
.br
.in -1c
.SS "Functions"

.in +1c
.ti -1c
.RI "char * \fBmdb_version\fP (int *major, int *minor, int *patch)"
.br
.RI "Return the LMDB library version information\&. "
.ti -1c
.RI "char * \fBmdb_strerror\fP (int err)"
.br
.RI "Return a string describing a given error code\&. "
.ti -1c
.RI "int \fBmdb_env_create\fP (\fBMDB_env\fP **env)"
.br
.RI "Create an LMDB environment handle\&. "
.ti -1c
.RI "int \fBmdb_env_open\fP (\fBMDB_env\fP *env, const char *path, unsigned int flags, \fBmdb_mode_t\fP mode)"
.br
.RI "Open an environment handle\&. "
.ti -1c
.RI "int \fBmdb_env_copy\fP (\fBMDB_env\fP *env, const char *path)"
.br
.RI "Copy an LMDB environment to the specified path\&. "
.ti -1c
.RI "int \fBmdb_env_copyfd\fP (\fBMDB_env\fP *env, \fBmdb_filehandle_t\fP fd)"
.br
.RI "Copy an LMDB environment to the specified file descriptor\&. "
.ti -1c
.RI "int \fBmdb_env_copy2\fP (\fBMDB_env\fP *env, const char *path, unsigned int flags)"
.br
.RI "Copy an LMDB environment to the specified path, with options\&. "
.ti -1c
.RI "int \fBmdb_env_copyfd2\fP (\fBMDB_env\fP *env, \fBmdb_filehandle_t\fP fd, unsigned int flags)"
.br
.RI "Copy an LMDB environment to the specified file descriptor, with options\&. "
.ti -1c
.RI "int \fBmdb_env_stat\fP (\fBMDB_env\fP *env, \fBMDB_stat\fP *stat)"
.br
.RI "Return statistics about the LMDB environment\&. "
.ti -1c
.RI "int \fBmdb_env_info\fP (\fBMDB_env\fP *env, \fBMDB_envinfo\fP *stat)"
.br
.RI "Return information about the LMDB environment\&. "
.ti -1c
.RI "int \fBmdb_env_sync\fP (\fBMDB_env\fP *env, int force)"
.br
.RI "Flush the data buffers to disk\&. "
.ti -1c
.RI "void \fBmdb_env_close\fP (\fBMDB_env\fP *env)"
.br
.RI "Close the environment and release the memory map\&. "
.ti -1c
.RI "int \fBmdb_env_set_flags\fP (\fBMDB_env\fP *env, unsigned int flags, int onoff)"
.br
.RI "Set environment flags\&. "
.ti -1c
.RI "int \fBmdb_env_get_flags\fP (\fBMDB_env\fP *env, unsigned int *flags)"
.br
.RI "Get environment flags\&. "
.ti -1c
.RI "int \fBmdb_env_get_path\fP (\fBMDB_env\fP *env, const char **path)"
.br
.RI "Return the path that was used in \fBmdb_env_open()\fP\&. "
.ti -1c
.RI "int \fBmdb_env_get_fd\fP (\fBMDB_env\fP *env, \fBmdb_filehandle_t\fP *fd)"
.br
.RI "Return the filedescriptor for the given environment\&. "
.ti -1c
.RI "int \fBmdb_env_set_mapsize\fP (\fBMDB_env\fP *env, size_t size)"
.br
.RI "Set the size of the memory map to use for this environment\&. "
.ti -1c
.RI "int \fBmdb_env_set_maxreaders\fP (\fBMDB_env\fP *env, unsigned int readers)"
.br
.RI "Set the maximum number of threads/reader slots for the environment\&. "
.ti -1c
.RI "int \fBmdb_env_get_maxreaders\fP (\fBMDB_env\fP *env, unsigned int *readers)"
.br
.RI "Get the maximum number of threads/reader slots for the environment\&. "
.ti -1c
.RI "int \fBmdb_env_set_maxdbs\fP (\fBMDB_env\fP *env, \fBMDB_dbi\fP dbs)"
.br
.RI "Set the maximum number of named databases for the environment\&. "
.ti -1c
.RI "int \fBmdb_env_get_maxkeysize\fP (\fBMDB_env\fP *env)"
.br
.RI "Get the maximum size of keys and \fBMDB_DUPSORT\fP data we can write\&. "
.ti -1c
.RI "int \fBmdb_env_set_userctx\fP (\fBMDB_env\fP *env, void *ctx)"
.br
.RI "Set application information associated with the \fBMDB_env\fP\&. "
.ti -1c
.RI "void * \fBmdb_env_get_userctx\fP (\fBMDB_env\fP *env)"
.br
.RI "Get the application information associated with the \fBMDB_env\fP\&. "
.ti -1c
.RI "int \fBmdb_env_set_assert\fP (\fBMDB_env\fP *env, \fBMDB_assert_func\fP *func)"
.br
.ti -1c
.RI "int \fBmdb_txn_begin\fP (\fBMDB_env\fP *env, \fBMDB_txn\fP *parent, unsigned int flags, \fBMDB_txn\fP **txn)"
.br
.RI "Create a transaction for use with the environment\&. "
.ti -1c
.RI "\fBMDB_env\fP * \fBmdb_txn_env\fP (\fBMDB_txn\fP *txn)"
.br
.RI "Returns the transaction's \fBMDB_env\fP\&. "
.ti -1c
.RI "size_t \fBmdb_txn_id\fP (\fBMDB_txn\fP *txn)"
.br
.RI "Return the transaction's ID\&. "
.ti -1c
.RI "int \fBmdb_txn_commit\fP (\fBMDB_txn\fP *txn)"
.br
.RI "Commit all the operations of a transaction into the database\&. "
.ti -1c
.RI "void \fBmdb_txn_abort\fP (\fBMDB_txn\fP *txn)"
.br
.RI "Abandon all the operations of the transaction instead of saving them\&. "
.ti -1c
.RI "void \fBmdb_txn_reset\fP (\fBMDB_txn\fP *txn)"
.br
.RI "Reset a read-only transaction\&. "
.ti -1c
.RI "int \fBmdb_txn_renew\fP (\fBMDB_txn\fP *txn)"
.br
.RI "Renew a read-only transaction\&. "
.ti -1c
.RI "int \fBmdb_dbi_open\fP (\fBMDB_txn\fP *txn, const char *name, unsigned int flags, \fBMDB_dbi\fP *dbi)"
.br
.RI "Open a database in the environment\&. "
.ti -1c
.RI "int \fBmdb_stat\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_stat\fP *stat)"
.br
.RI "Retrieve statistics for a database\&. "
.ti -1c
.RI "int \fBmdb_dbi_flags\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, unsigned int *flags)"
.br
.RI "Retrieve the DB flags for a database handle\&. "
.ti -1c
.RI "void \fBmdb_dbi_close\fP (\fBMDB_env\fP *env, \fBMDB_dbi\fP dbi)"
.br
.RI "Close a database handle\&. Normally unnecessary\&. Use with care: "
.ti -1c
.RI "int \fBmdb_drop\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, int del)"
.br
.RI "Empty or delete+close a database\&. "
.ti -1c
.RI "int \fBmdb_set_compare\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_cmp_func\fP *cmp)"
.br
.RI "Set a custom key comparison function for a database\&. "
.ti -1c
.RI "int \fBmdb_set_dupsort\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_cmp_func\fP *cmp)"
.br
.RI "Set a custom data comparison function for a \fBMDB_DUPSORT\fP database\&. "
.ti -1c
.RI "int \fBmdb_set_relfunc\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_rel_func\fP *rel)"
.br
.RI "Set a relocation function for a \fBMDB_FIXEDMAP\fP database\&. "
.ti -1c
.RI "int \fBmdb_set_relctx\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, void *ctx)"
.br
.RI "Set a context pointer for a \fBMDB_FIXEDMAP\fP database's relocation function\&. "
.ti -1c
.RI "int \fBmdb_get\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_val\fP *key, \fBMDB_val\fP *data)"
.br
.RI "Get items from a database\&. "
.ti -1c
.RI "int \fBmdb_put\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_val\fP *key, \fBMDB_val\fP *data, unsigned int flags)"
.br
.RI "Store items into a database\&. "
.ti -1c
.RI "int \fBmdb_del\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_val\fP *key, \fBMDB_val\fP *data)"
.br
.RI "Delete items from a database\&. "
.ti -1c
.RI "int \fBmdb_cursor_open\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, \fBMDB_cursor\fP **cursor)"
.br
.RI "Create a cursor handle\&. "
.ti -1c
.RI "void \fBmdb_cursor_close\fP (\fBMDB_cursor\fP *cursor)"
.br
.RI "Close a cursor handle\&. "
.ti -1c
.RI "int \fBmdb_cursor_renew\fP (\fBMDB_txn\fP *txn, \fBMDB_cursor\fP *cursor)"
.br
.RI "Renew a cursor handle\&. "
.ti -1c
.RI "\fBMDB_txn\fP * \fBmdb_cursor_txn\fP (\fBMDB_cursor\fP *cursor)"
.br
.RI "Return the cursor's transaction handle\&. "
.ti -1c
.RI "\fBMDB_dbi\fP \fBmdb_cursor_dbi\fP (\fBMDB_cursor\fP *cursor)"
.br
.RI "Return the cursor's database handle\&. "
.ti -1c
.RI "int \fBmdb_cursor_get\fP (\fBMDB_cursor\fP *cursor, \fBMDB_val\fP *key, \fBMDB_val\fP *data, \fBMDB_cursor_op\fP op)"
.br
.RI "Retrieve by cursor\&. "
.ti -1c
.RI "int \fBmdb_cursor_put\fP (\fBMDB_cursor\fP *cursor, \fBMDB_val\fP *key, \fBMDB_val\fP *data, unsigned int flags)"
.br
.RI "Store by cursor\&. "
.ti -1c
.RI "int \fBmdb_cursor_del\fP (\fBMDB_cursor\fP *cursor, unsigned int flags)"
.br
.RI "Delete current key/data pair\&. "
.ti -1c
.RI "int \fBmdb_cursor_count\fP (\fBMDB_cursor\fP *cursor, size_t *countp)"
.br
.RI "Return count of duplicates for current key\&. "
.ti -1c
.RI "int \fBmdb_cmp\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, const \fBMDB_val\fP *a, const \fBMDB_val\fP *b)"
.br
.RI "Compare two data items according to a particular database\&. "
.ti -1c
.RI "int \fBmdb_dcmp\fP (\fBMDB_txn\fP *txn, \fBMDB_dbi\fP dbi, const \fBMDB_val\fP *a, const \fBMDB_val\fP *b)"
.br
.RI "Compare two data items according to a particular database\&. "
.ti -1c
.RI "int \fBmdb_reader_list\fP (\fBMDB_env\fP *env, \fBMDB_msg_func\fP *func, void *ctx)"
.br
.RI "Dump the entries in the reader lock table\&. "
.ti -1c
.RI "int \fBmdb_reader_check\fP (\fBMDB_env\fP *env, int *dead)"
.br
.RI "Check for stale entries in the reader lock table\&. "
.in -1c
.SH "Detailed Description"
.PP 
Lightning memory-mapped database library\&. 


.SH "Typedef Documentation"
.PP 
.SS "typedef mode_t \fBmdb_mode_t\fP"
Unix permissions for creating files, or dummy definition for Windows 
.SS "typedef int \fBmdb_filehandle_t\fP"
An abstraction for a file handle\&. On POSIX systems file handles are small integers\&. On Windows they're opaque pointers\&. 
.SH "Author"
.PP 
Generated automatically by Doxygen for LMDB from the source code\&.