NextGraph
/
lmdb
mirror of https://github.com/nextgraph-org/lmdb.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
Read-only mirror of official repo on openldap.org. Issues and pull requests here are ignored. Use OpenLDAP ITS for issues.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
126 Commits
14 Branches
24 Tags
3.2 MiB
 
 
 
Tag: Branch: Tree: 8d89a53165
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from '8d89a53165'
${ noResults }
lmdb/libraries/libmdb/mdb.c

4330 lines
108 KiB
Raw Blame History

/** @file mdb.c
* @brief memory-mapped database library
*
* A Btree-based database management library modeled loosely on the
* BerkeleyDB API, but much simplified.
*/
/*
* Copyright 2011 Howard Chu, Symas Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*
* This code is derived from btree.c written by Martin Hedenfalk.
*
* Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <sys/uio.h>
#include <sys/mman.h>
#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#include <fcntl.h>
#endif
#include <assert.h>
#include <errno.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#ifndef _WIN32
#include <pthread.h>
#endif
#include "mdb.h"
#include "midl.h"
/** @defgroup internal MDB Internals
* @{
*/
/** @defgroup compat Windows Compatibility Macros
* @{
*/
#ifdef _WIN32
#define pthread_t DWORD
#define pthread_mutex_t HANDLE
#define pthread_key_t DWORD
#define pthread_self() GetCurrentThreadId()
#define pthread_key_create(x,y) *(x) = TlsAlloc()
#define pthread_key_delete(x) TlsFree(x)
#define pthread_getspecific(x) TlsGetValue(x)
#define pthread_setspecific(x,y) TlsSetValue(x,y)
#define pthread_mutex_unlock(x) ReleaseMutex(x)
#define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE)
#define LOCK_MUTEX_R(env) pthread_mutex_lock(env->me_rmutex)
#define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(env->me_rmutex)
#define LOCK_MUTEX_W(env) pthread_mutex_lock(env->me_wmutex)
#define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(env->me_wmutex)
#define getpid() GetCurrentProcessId()
#define fdatasync(fd) !FlushFileBuffers(fd)
#define ErrCode() GetLastError()
#define GetPageSize(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
#define close(fd) CloseHandle(fd)
#define munmap(ptr,len) UnmapViewOfFile(ptr)
#else
#define LOCK_MUTEX_R(env) pthread_mutex_lock(&env->me_txns->mti_mutex)
#define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&env->me_txns->mti_mutex)
#define LOCK_MUTEX_W(env) pthread_mutex_lock(&env->me_txns->mti_wmutex)
#define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&env->me_txns->mti_wmutex)
#define ErrCode() errno
#define HANDLE int
#define INVALID_HANDLE_VALUE -1
#define GetPageSize(x) (x) = sysconf(_SC_PAGE_SIZE)
#endif
/** @} */
#ifndef _WIN32
/* Note: If O_DSYNC is undefined but exists in /usr/include,
* preferably set some compiler flag to get the definition.
* Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
*/
#ifndef MDB_DSYNC
# define MDB_DSYNC O_DSYNC
#endif
#endif
typedef ULONG pgno_t;
#ifndef DEBUG
#define DEBUG 0
#endif
#if !(__STDC_VERSION__ >= 199901L || defined(__GNUC__))
# define DPRINTF (void) /* Vararg macros may be unsupported */
#elif DEBUG
# define DPRINTF(fmt, ...) /* Requires 2 or more args */ \
fprintf(stderr, "%s:%d:(%p) " fmt "\n", __func__, __LINE__, pthread_self(), __VA_ARGS__)
#else
# define DPRINTF(fmt, ...) ((void) 0)
#endif
#define DPUTS(arg) DPRINTF("%s", arg)
#define PAGESIZE 4096
#define MDB_MINKEYS 2
#define MDB_MAGIC 0xBEEFC0DE
#define MDB_VERSION 1
#define MAXKEYSIZE 511
#if DEBUG
#define KBUF (MAXKEYSIZE*2+1)
#define DKBUF char kbuf[KBUF]
#define DKEY(x) mdb_dkey(x, kbuf)
#else
#define DKBUF
#define DKEY(x)
#endif
/* The DB view is always consistent because all writes are wrapped in
* the wmutex. Finer-grained locks aren't necessary.
*/
#ifndef LAZY_LOCKS
#define LAZY_LOCKS 1
#endif
#if LAZY_LOCKS
#define LAZY_MUTEX_LOCK(x)
#define LAZY_MUTEX_UNLOCK(x)
#define LAZY_RWLOCK_UNLOCK(x)
#define LAZY_RWLOCK_WRLOCK(x)
#define LAZY_RWLOCK_RDLOCK(x)
#define LAZY_RWLOCK_DEF(x)
#define LAZY_RWLOCK_INIT(x,y)
#define LAZY_RWLOCK_DESTROY(x)
#else
#define LAZY_MUTEX_LOCK(x) pthread_mutex_lock(x)
#define LAZY_MUTEX_UNLOCK(x) pthread_mutex_unlock(x)
#define LAZY_RWLOCK_UNLOCK(x) pthread_rwlock_unlock(x)
#define LAZY_RWLOCK_WRLOCK(x) pthread_rwlock_wrlock(x)
#define LAZY_RWLOCK_RDLOCK(x) pthread_rwlock_rdlock(x)
#define LAZY_RWLOCK_DEF(x) pthread_rwlock_t x
#define LAZY_RWLOCK_INIT(x,y) pthread_rwlock_init(x,y)
#define LAZY_RWLOCK_DESTROY(x) pthread_rwlock_destroy(x)
#endif
#define P_INVALID (~0UL)
#define F_ISSET(w, f) (((w) & (f)) == (f))
typedef uint16_t indx_t;
#define DEFAULT_READERS 126
#define DEFAULT_MAPSIZE 1048576
/* Lock descriptor stuff */
#ifndef CACHELINE
#define CACHELINE 64 /* most CPUs. Itanium uses 128 */
#endif
typedef struct MDB_rxbody {
ULONG mrb_txnid;
pid_t mrb_pid;
pthread_t mrb_tid;
} MDB_rxbody;
typedef struct MDB_reader {
union {
MDB_rxbody mrx;
#define mr_txnid mru.mrx.mrb_txnid
#define mr_pid mru.mrx.mrb_pid
#define mr_tid mru.mrx.mrb_tid
/* cache line alignment */
char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
} mru;
} MDB_reader;
typedef struct MDB_txbody {
uint32_t mtb_magic;
uint32_t mtb_version;
/* For POSIX the actual mutexes reside in shared memory.
* On Windows, mutexes are allocated by the kernel; we store
* the name in shared memory so that other processes can
* grab them.
*/
#ifdef _WIN32
char mtb_rmname[32];
#else
pthread_mutex_t mtb_mutex;
#endif
ULONG mtb_txnid;
uint32_t mtb_numreaders;
uint32_t mtb_me_toggle;
} MDB_txbody;
typedef struct MDB_txninfo {
union {
MDB_txbody mtb;
#define mti_magic mt1.mtb.mtb_magic
#define mti_version mt1.mtb.mtb_version
#define mti_mutex mt1.mtb.mtb_mutex
#define mti_rmname mt1.mtb.mtb_rmname
#define mti_txnid mt1.mtb.mtb_txnid
#define mti_numreaders mt1.mtb.mtb_numreaders
#define mti_me_toggle mt1.mtb.mtb_me_toggle
char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
} mt1;
union {
#ifdef _WIN32
char mt2_wmname[32];
#define mti_wmname mt2.mt2_wmname
#else
pthread_mutex_t mt2_wmutex;
#define mti_wmutex mt2.mt2_wmutex
#endif
char pad[(sizeof(pthread_mutex_t)+CACHELINE-1) & ~(CACHELINE-1)];
} mt2;
MDB_reader mti_readers[1];
} MDB_txninfo;
/* Common header for all page types. Overflow pages
* occupy a number of contiguous pages with no
* headers on any page after the first.
*/
typedef struct MDB_page { /* represents a page of storage */
#define mp_pgno mp_p.p_pgno
union padded {
pgno_t p_pgno; /* page number */
void * p_align; /* for IL32P64 */
} mp_p;
#define P_BRANCH 0x01 /* branch page */
#define P_LEAF 0x02 /* leaf page */
#define P_OVERFLOW 0x04 /* overflow page */
#define P_META 0x08 /* meta page */
#define P_DIRTY 0x10 /* dirty page */
#define P_LEAF2 0x20 /* DB with small, fixed size keys and no data */
uint32_t mp_flags;
#define mp_lower mp_pb.pb.pb_lower
#define mp_upper mp_pb.pb.pb_upper
#define mp_pages mp_pb.pb_pages
union page_bounds {
struct {
indx_t pb_lower; /* lower bound of free space */
indx_t pb_upper; /* upper bound of free space */
} pb;
uint32_t pb_pages; /* number of overflow pages */
} mp_pb;
indx_t mp_ptrs[1]; /* dynamic size */
} MDB_page;
#define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
#define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
#define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
#define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
((env)->me_psize - PAGEHDRSZ))
#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 OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
typedef struct MDB_db {
uint32_t md_pad; /* also ksize for LEAF2 pages */
uint16_t md_flags;
uint16_t md_depth;
ULONG md_branch_pages;
ULONG md_leaf_pages;
ULONG md_overflow_pages;
ULONG md_entries;
pgno_t md_root;
} MDB_db;
#define FREE_DBI 0
#define MAIN_DBI 1
typedef struct MDB_meta { /* meta (footer) page content */
uint32_t mm_magic;
uint32_t mm_version;
void *mm_address; /* address for fixed mapping */
size_t mm_mapsize; /* size of mmap region */
MDB_db mm_dbs[2]; /* first is free space, 2nd is main db */
#define mm_psize mm_dbs[0].md_pad
#define mm_flags mm_dbs[0].md_flags
pgno_t mm_last_pg; /* last used page in file */
ULONG mm_txnid; /* txnid that committed this page */
} MDB_meta;
typedef struct MDB_dhead { /* a dirty page */
MDB_page *md_parent;
unsigned md_pi; /* parent index */
int md_num;
} MDB_dhead;
typedef struct MDB_dpage {
MDB_dhead h;
MDB_page p;
} MDB_dpage;
typedef struct MDB_oldpages {
struct MDB_oldpages *mo_next;
ULONG mo_txnid;
pgno_t mo_pages[1]; /* dynamic */
} MDB_oldpages;
typedef struct MDB_pageparent {
MDB_page *mp_page;
MDB_page *mp_parent;
unsigned mp_pi;
} MDB_pageparent;
static MDB_dpage *mdb_alloc_page(MDB_txn *txn, MDB_dbi dbi, MDB_page *parent, unsigned int parent_idx, int num);
static int mdb_touch(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *mp);
typedef struct MDB_ppage { /* ordered list of pages */
MDB_page *mp_page;
unsigned int mp_ki; /* cursor index on page */
} MDB_ppage;
#define CURSOR_TOP(c) (&(c)->mc_stack[(c)->mc_snum-1])
#define CURSOR_PARENT(c) (&(c)->mc_stack[(c)->mc_snum-2])
#define CURSOR_STACK 32
struct MDB_xcursor;
struct MDB_cursor {
MDB_txn *mc_txn;
MDB_ppage mc_stack[CURSOR_STACK]; /* stack of parent pages */
unsigned int mc_snum; /* number of pushed pages */
MDB_dbi mc_dbi;
unsigned int mc_flags;
#define C_INITIALIZED 0x01
#define C_EOF 0x02
#define C_XDIRTY 0x04
struct MDB_xcursor *mc_xcursor;
};
#define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
typedef struct MDB_node {
#define mn_pgno mn_p.np_pgno
#define mn_dsize mn_p.np_dsize
union {
pgno_t np_pgno; /* child page number */
uint32_t np_dsize; /* leaf data size */
} mn_p;
unsigned int mn_flags:4;
unsigned int mn_ksize:12; /* key size */
#define F_BIGDATA 0x01 /* data put on overflow page */
#define F_SUBDATA 0x02 /* data is a sub-database */
#define F_DUPDATA 0x04 /* data has duplicates */
char mn_data[1];
} MDB_node;
typedef struct MDB_dbx {
MDB_val md_name;
MDB_cmp_func *md_cmp; /* user compare function */
MDB_cmp_func *md_dcmp; /* user dupsort function */
MDB_rel_func *md_rel; /* user relocate function */
MDB_dbi md_parent;
unsigned int md_dirty;
} MDB_dbx;
struct MDB_txn {
pgno_t mt_next_pgno; /* next unallocated page */
ULONG mt_txnid;
MDB_env *mt_env;
pgno_t *mt_free_pgs; /* this is an IDL */
union {
ID2L dirty_list; /* modified pages */
MDB_reader *reader;
} mt_u;
MDB_dbx *mt_dbxs; /* array */
MDB_db *mt_dbs;
unsigned int mt_numdbs;
#define MDB_TXN_RDONLY 0x01 /* read-only transaction */
#define MDB_TXN_ERROR 0x02 /* an error has occurred */
unsigned int mt_flags;
unsigned int mt_toggle;
};
/* Context for sorted-dup records */
typedef struct MDB_xcursor {
MDB_cursor mx_cursor;
MDB_txn mx_txn;
MDB_dbx mx_dbxs[4];
MDB_db mx_dbs[4];
} MDB_xcursor;
struct MDB_env {
HANDLE me_fd;
HANDLE me_lfd;
HANDLE me_mfd; /* just for writing the meta pages */
#define MDB_FATAL_ERROR 0x80000000U
uint32_t me_flags;
uint32_t me_extrapad; /* unused for now */
unsigned int me_maxreaders;
unsigned int me_numdbs;
unsigned int me_maxdbs;
char *me_path;
char *me_map;
MDB_txninfo *me_txns;
MDB_meta *me_metas[2];
MDB_txn *me_txn; /* current write transaction */
size_t me_mapsize;
off_t me_size; /* current file size */
pgno_t me_maxpg; /* me_mapsize / me_psize */
unsigned int me_psize;
unsigned int me_db_toggle;
MDB_dbx *me_dbxs; /* array */
MDB_db *me_dbs[2];
MDB_oldpages *me_pghead;
pthread_key_t me_txkey; /* thread-key for readers */
MDB_dpage *me_dpages;
pgno_t me_free_pgs[MDB_IDL_UM_SIZE];
ID2 me_dirty_list[MDB_IDL_DB_SIZE];
LAZY_RWLOCK_DEF(me_dblock);
#ifdef _WIN32
HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
HANDLE me_wmutex;
#endif
};
#define NODESIZE offsetof(MDB_node, mn_data)
#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]))
#define NODEKEY(node) (void *)((node)->mn_data)
#define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
#define NODEPGNO(node) ((node)->mn_pgno)
#define NODEDSZ(node) ((node)->mn_dsize)
#define NODEKSZ(node) ((node)->mn_ksize)
#define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
#define MDB_SET_KEY(node, key) if (key!=NULL) {(key)->mv_size = NODEKSZ(node); (key)->mv_data = NODEKEY(node);}
#define MDB_COMMIT_PAGES 64 /* max number of pages to write in one commit */
static int mdb_search_page_root(MDB_txn *txn,
MDB_dbi dbi, MDB_val *key,
MDB_cursor *cursor, int modify,
MDB_pageparent *mpp);
static int mdb_search_page(MDB_txn *txn,
MDB_dbi dbi, MDB_val *key,
MDB_cursor *cursor, int modify,
MDB_pageparent *mpp);
static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
static int mdb_env_read_meta(MDB_env *env, int *which);
static int mdb_env_write_meta(MDB_txn *txn);
static int mdb_get_page(MDB_txn *txn, pgno_t pgno, MDB_page **mp);
static MDB_node *mdb_search_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp,
MDB_val *key, int *exactp, unsigned int *kip);
static int mdb_add_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp,
indx_t indx, MDB_val *key, MDB_val *data,
pgno_t pgno, uint8_t flags);
static void mdb_del_node(MDB_page *mp, indx_t indx, int ksize);
static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, unsigned int ki,
MDB_pageparent *mpp, MDB_node *leaf);
static int mdb_put0(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data, unsigned int flags);
static int mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
static int mdb_rebalance(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *mp);
static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key);
static int mdb_move_node(MDB_txn *txn, MDB_dbi dbi,
MDB_pageparent *src, indx_t srcindx,
MDB_pageparent *dst, indx_t dstindx);
static int mdb_merge(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *src,
MDB_pageparent *dst);
static int mdb_split(MDB_txn *txn, MDB_dbi dbi, MDB_page **mpp,
unsigned int *newindxp, MDB_val *newkey,
MDB_val *newdata, pgno_t newpgno);
static MDB_dpage *mdb_new_page(MDB_txn *txn, MDB_dbi dbi, uint32_t flags, int num);
static void cursor_pop_page(MDB_cursor *cursor);
static MDB_ppage *cursor_push_page(MDB_cursor *cursor,
MDB_page *mp);
static int mdb_sibling(MDB_cursor *cursor, int move_right);
static int mdb_cursor_next(MDB_cursor *cursor,
MDB_val *key, MDB_val *data, MDB_cursor_op op);
static int mdb_cursor_prev(MDB_cursor *cursor,
MDB_val *key, MDB_val *data, MDB_cursor_op op);
static int mdb_cursor_set(MDB_cursor *cursor,
MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp);
static int mdb_cursor_first(MDB_cursor *cursor,
MDB_val *key, MDB_val *data);
static int mdb_cursor_last(MDB_cursor *cursor,
MDB_val *key, MDB_val *data);
static void mdb_xcursor_init0(MDB_cursor *mc);
static void mdb_xcursor_init1(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx,
MDB_page *mp, MDB_node *node);
static void mdb_xcursor_fini(MDB_cursor *mc);
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 memncmp(const void *s1, size_t n1,
const void *s2, size_t n2);
static int memnrcmp(const void *s1, size_t n1,
const void *s2, size_t n2);
#ifdef _WIN32
static SECURITY_DESCRIPTOR mdb_null_sd;
static SECURITY_ATTRIBUTES mdb_all_sa;
static int mdb_sec_inited;
#endif
static int
memncmp(const void *s1, size_t n1, const void *s2, size_t n2)
{
int diff, len_diff = -1;
if (n1 >= n2) {
len_diff = (n1 > n2);
n1 = n2;
}
diff = memcmp(s1, s2, n1);
return diff ? diff : len_diff;
}
static int
memnrcmp(const void *s1, size_t n1, const void *s2, size_t n2)
{
const unsigned char *p1, *p2, *p1_lim;
if (n2 == 0)
return n1 != 0;
if (n1 == 0)
return -1;
p1 = (const unsigned char *)s1 + n1 - 1;
p2 = (const unsigned char *)s2 + n2 - 1;
for (p1_lim = (n1 <= n2 ? s1 : s2); *p1 == *p2; p1--, p2--) {
if (p1 == p1_lim)
return (p1 != s1) ? (p1 != p2) : (p2 != s2) ? -1 : 0;
}
return *p1 - *p2;
}
char *
mdb_version(int *maj, int *min, int *pat)
{
if (maj) *maj = MDB_VERSION_MAJOR;
if (min) *min = MDB_VERSION_MINOR;
if (pat) *pat = MDB_VERSION_PATCH;
return MDB_VERSION_STRING;
}
static char *const mdb_errstr[] = {
"MDB_KEYEXIST: Key/data pair already exists",
"MDB_NOTFOUND: No matching key/data pair found",
"MDB_PAGE_NOTFOUND: Requested page not found",
"MDB_CORRUPTED: Located page was wrong type",
"MDB_PANIC: Update of meta page failed",
"MDB_VERSION_MISMATCH: Database environment version mismatch"
};
char *
mdb_strerror(int err)
{
if (!err)
return ("Successful return: 0");
if (err >= MDB_KEYEXIST && err <= MDB_VERSION_MISMATCH)
return mdb_errstr[err - MDB_KEYEXIST];
return strerror(err);
}
#if DEBUG
static char *
mdb_dkey(MDB_val *key, char *buf)
{
char *ptr = buf;
unsigned char *c = key->mv_data;
unsigned int i;
if (key->mv_size > MAXKEYSIZE)
return "MAXKEYSIZE";
for (i=0; i<key->mv_size; i++)
ptr += sprintf(ptr, "%02x", *c++);
return buf;
}
#endif
int
mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
{
if (txn->mt_dbxs[dbi].md_cmp)
return txn->mt_dbxs[dbi].md_cmp(a, b);
if (txn->mt_dbs[dbi].md_flags & (MDB_REVERSEKEY
#if __BYTE_ORDER == __LITTLE_ENDIAN
|MDB_INTEGERKEY
#endif
))
return memnrcmp(a->mv_data, a->mv_size, b->mv_data, b->mv_size);
else
return memncmp((char *)a->mv_data, a->mv_size, b->mv_data, b->mv_size);
}
int
mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
{
if (txn->mt_dbxs[dbi].md_dcmp)
return txn->mt_dbxs[dbi].md_dcmp(a, b);
if (txn->mt_dbs[dbi].md_flags & (0
#if __BYTE_ORDER == __LITTLE_ENDIAN
|MDB_INTEGERDUP
#endif
))
return memnrcmp(a->mv_data, a->mv_size, b->mv_data, b->mv_size);
else
return memncmp((char *)a->mv_data, a->mv_size, b->mv_data, b->mv_size);
}
/* Allocate new page(s) for writing */
static MDB_dpage *
mdb_alloc_page(MDB_txn *txn, MDB_dbi dbi, MDB_page *parent, unsigned int parent_idx, int num)
{
MDB_dpage *dp;
pgno_t pgno = P_INVALID;
ID2 mid;
if (txn->mt_txnid > 2) {
if (!txn->mt_env->me_pghead && dbi != FREE_DBI &&
txn->mt_dbs[FREE_DBI].md_root != P_INVALID) {
/* See if there's anything in the free DB */
MDB_cursor mc;
MDB_pageparent mpp;
MDB_node *leaf;
ULONG *kptr, oldest;
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
mc.mc_txn = txn;
mc.mc_dbi = dbi;
mc.mc_snum = 0;
mc.mc_flags = 0;
mdb_search_page(txn, FREE_DBI, NULL, &mc, 0, &mpp);
leaf = NODEPTR(mpp.mp_page, 0);
kptr = (ULONG *)NODEKEY(leaf);
{
unsigned int i;
oldest = txn->mt_txnid - 1;
for (i=0; i<txn->mt_env->me_txns->mti_numreaders; i++) {
ULONG mr = txn->mt_env->me_txns->mti_readers[i].mr_txnid;
if (mr && mr < oldest)
oldest = mr;
}
}
if (oldest > *kptr) {
/* It's usable, grab it.
*/
MDB_oldpages *mop;
MDB_ppage *top;
MDB_val data;
pgno_t *idl;
mdb_read_data(txn, leaf, &data);
idl = (ULONG *)data.mv_data;
mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t));
mop->mo_next = txn->mt_env->me_pghead;
mop->mo_txnid = *kptr;
txn->mt_env->me_pghead = mop;
memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl));
#if DEBUG > 1
{
unsigned int i;
DPRINTF("IDL read txn %lu root %lu num %lu",
mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
for (i=0; i<idl[0]; i++) {
DPRINTF("IDL %lu", idl[i+1]);
}
}
#endif
/* drop this IDL from the DB */
top = CURSOR_TOP(&mc);
top->mp_ki = 0;
mc.mc_flags = C_INITIALIZED;
mdb_cursor_del(&mc, 0);
}
}
if (txn->mt_env->me_pghead) {
MDB_oldpages *mop = txn->mt_env->me_pghead;
if (num > 1) {
/* FIXME: For now, always use fresh pages. We
* really ought to search the free list for a
* contiguous range.
*/
;
} else {
/* peel pages off tail, so we only have to truncate the list */
pgno = MDB_IDL_LAST(mop->mo_pages);
if (MDB_IDL_IS_RANGE(mop->mo_pages)) {
mop->mo_pages[2]++;
if (mop->mo_pages[2] > mop->mo_pages[1])
mop->mo_pages[0] = 0;
} else {
mop->mo_pages[0]--;
}
if (MDB_IDL_IS_ZERO(mop->mo_pages)) {
txn->mt_env->me_pghead = mop->mo_next;
free(mop);
}
}
}
}
if (pgno == P_INVALID) {
/* DB size is maxed out */
if (txn->mt_next_pgno + num >= txn->mt_env->me_maxpg)
return NULL;
}
if (txn->mt_env->me_dpages && num == 1) {
dp = txn->mt_env->me_dpages;
txn->mt_env->me_dpages = (MDB_dpage *)dp->h.md_parent;
} else {
if ((dp = malloc(txn->mt_env->me_psize * num + sizeof(MDB_dhead))) == NULL)
return NULL;
}
dp->h.md_num = num;
dp->h.md_parent = parent;
dp->h.md_pi = parent_idx;
if (pgno == P_INVALID) {
dp->p.mp_pgno = txn->mt_next_pgno;
txn->mt_next_pgno += num;
} else {
dp->p.mp_pgno = pgno;
}
mid.mid = dp->p.mp_pgno;
mid.mptr = dp;
mdb_mid2l_insert(txn->mt_u.dirty_list, &mid);
return dp;
}
/* Touch a page: make it dirty and re-insert into tree with updated pgno.
*/
static int
mdb_touch(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *pp)
{
MDB_page *mp = pp->mp_page;
pgno_t pgno;
assert(txn != NULL);
assert(pp != NULL);
if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
MDB_dpage *dp;
if ((dp = mdb_alloc_page(txn, dbi, pp->mp_parent, pp->mp_pi, 1)) == NULL)
return ENOMEM;
DPRINTF("touched db %u page %lu -> %lu", dbi, mp->mp_pgno, dp->p.mp_pgno);
assert(mp->mp_pgno != dp->p.mp_pgno);
mdb_midl_insert(txn->mt_free_pgs, mp->mp_pgno);
pgno = dp->p.mp_pgno;
memcpy(&dp->p, mp, txn->mt_env->me_psize);
mp = &dp->p;
mp->mp_pgno = pgno;
mp->mp_flags |= P_DIRTY;
/* Update the page number to new touched page. */
if (pp->mp_parent != NULL)
NODEPGNO(NODEPTR(pp->mp_parent, pp->mp_pi)) = mp->mp_pgno;
pp->mp_page = mp;
}
return 0;
}
int
mdb_env_sync(MDB_env *env, int force)
{
int rc = 0;
if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
if (fdatasync(env->me_fd))
rc = ErrCode();
}
return rc;
}
static inline void
mdb_txn_reset0(MDB_txn *txn);
static inline int
mdb_txn_renew0(MDB_txn *txn)
{
MDB_env *env = txn->mt_env;
if (txn->mt_flags & MDB_TXN_RDONLY) {
MDB_reader *r = pthread_getspecific(env->me_txkey);
if (!r) {
unsigned int i;
pid_t pid = getpid();
pthread_t tid = pthread_self();
LOCK_MUTEX_R(env);
for (i=0; i<env->me_txns->mti_numreaders; i++)
if (env->me_txns->mti_readers[i].mr_pid == 0)
break;
if (i == env->me_maxreaders) {
UNLOCK_MUTEX_R(env);
return ENOMEM;
}
env->me_txns->mti_readers[i].mr_pid = pid;
env->me_txns->mti_readers[i].mr_tid = tid;
if (i >= env->me_txns->mti_numreaders)
env->me_txns->mti_numreaders = i+1;
UNLOCK_MUTEX_R(env);
r = &env->me_txns->mti_readers[i];
pthread_setspecific(env->me_txkey, r);
}
txn->mt_txnid = env->me_txns->mti_txnid;
txn->mt_toggle = env->me_txns->mti_me_toggle;
r->mr_txnid = txn->mt_txnid;
txn->mt_u.reader = r;
} else {
LOCK_MUTEX_W(env);
txn->mt_txnid = env->me_txns->mti_txnid+1;
txn->mt_toggle = env->me_txns->mti_me_toggle;
txn->mt_u.dirty_list = env->me_dirty_list;
txn->mt_u.dirty_list[0].mid = 0;
txn->mt_free_pgs = env->me_free_pgs;
txn->mt_free_pgs[0] = 0;
txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
env->me_txn = txn;
}
/* Copy the DB arrays */
LAZY_RWLOCK_RDLOCK(&env->me_dblock);
txn->mt_numdbs = env->me_numdbs;
txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db));
if (txn->mt_numdbs > 2)
memcpy(txn->mt_dbs+2, env->me_dbs[env->me_db_toggle]+2,
(txn->mt_numdbs - 2) * sizeof(MDB_db));
LAZY_RWLOCK_UNLOCK(&env->me_dblock);
return MDB_SUCCESS;
}
int
mdb_txn_renew(MDB_txn *txn)
{
int rc;
if (!txn)
return EINVAL;
if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
DPUTS("environment had fatal error, must shutdown!");
return MDB_PANIC;
}
rc = mdb_txn_renew0(txn);
if (rc == MDB_SUCCESS) {
DPRINTF("renew txn %lu%c %p on mdbenv %p, root page %lu",
txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
(void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
}
return rc;
}
int
mdb_txn_begin(MDB_env *env, unsigned int flags, MDB_txn **ret)
{
MDB_txn *txn;
int rc;
if (env->me_flags & MDB_FATAL_ERROR) {
DPUTS("environment had fatal error, must shutdown!");
return MDB_PANIC;
}
if ((txn = calloc(1, sizeof(MDB_txn) + env->me_maxdbs * sizeof(MDB_db))) == NULL) {
DPRINTF("calloc: %s", strerror(ErrCode()));
return ENOMEM;
}
txn->mt_dbs = (MDB_db *)(txn+1);
if (flags & MDB_RDONLY) {
txn->mt_flags |= MDB_TXN_RDONLY;
}
txn->mt_env = env;
rc = mdb_txn_renew0(txn);
if (rc)
free(txn);
else {
*ret = txn;
DPRINTF("begin txn %lu%c %p on mdbenv %p, root page %lu",
txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
(void *) env, txn->mt_dbs[MAIN_DBI].md_root);
}
return rc;
}
static inline void
mdb_txn_reset0(MDB_txn *txn)
{
MDB_env *env = txn->mt_env;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
txn->mt_u.reader->mr_txnid = 0;
} else {
MDB_oldpages *mop;
MDB_dpage *dp;
unsigned int i;
/* return all dirty pages to dpage list */
for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
dp = txn->mt_u.dirty_list[i].mptr;
if (dp->h.md_num == 1) {
dp->h.md_parent = (MDB_page *)txn->mt_env->me_dpages;
txn->mt_env->me_dpages = dp;
} else {
/* large pages just get freed directly */
free(dp);
}
}
while ((mop = txn->mt_env->me_pghead)) {
txn->mt_env->me_pghead = mop->mo_next;
free(mop);
}
env->me_txn = NULL;
for (i=2; i<env->me_numdbs; i++)
env->me_dbxs[i].md_dirty = 0;
UNLOCK_MUTEX_W(env);
}
}
void
mdb_txn_reset(MDB_txn *txn)
{
if (txn == NULL)
return;
DPRINTF("reset txn %lu%c %p on mdbenv %p, root page %lu",
txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
(void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
mdb_txn_reset0(txn);
}
void
mdb_txn_abort(MDB_txn *txn)
{
if (txn == NULL)
return;
DPRINTF("abort txn %lu%c %p on mdbenv %p, root page %lu",
txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
(void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
mdb_txn_reset0(txn);
free(txn);
}
int
mdb_txn_commit(MDB_txn *txn)
{
int n, done;
unsigned int i;
ssize_t rc;
off_t size;
MDB_dpage *dp;
MDB_env *env;
pgno_t next;
assert(txn != NULL);
assert(txn->mt_env != NULL);
env = txn->mt_env;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
mdb_txn_abort(txn);
return MDB_SUCCESS;
}
if (txn != env->me_txn) {
DPUTS("attempt to commit unknown transaction");
mdb_txn_abort(txn);
return EINVAL;
}
if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
DPUTS("error flag is set, can't commit");
mdb_txn_abort(txn);
return EINVAL;
}
if (!txn->mt_u.dirty_list[0].mid)
goto done;
DPRINTF("committing txn %lu %p on mdbenv %p, root page %lu",
txn->mt_txnid, txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root);
/* should only be one record now */
if (env->me_pghead) {
MDB_pageparent mpp;
/* make sure first page of freeDB is touched and on freelist */
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
mdb_search_page(txn, FREE_DBI, NULL, NULL, 1, &mpp);
}
/* save to free list */
if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
MDB_val key, data;
MDB_pageparent mpp;
ULONG i;
/* make sure last page of freeDB is touched and on freelist */
key.mv_size = MAXKEYSIZE+1;
key.mv_data = NULL;
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
mdb_search_page(txn, FREE_DBI, &key, NULL, 1, &mpp);
#if DEBUG > 1
{
unsigned int i;
ULONG *idl = txn->mt_free_pgs;
DPRINTF("IDL write txn %lu root %lu num %lu",
txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
for (i=0; i<idl[0]; i++) {
DPRINTF("IDL %lu", idl[i+1]);
}
}
#endif
/* write to last page of freeDB */
key.mv_size = sizeof(pgno_t);
key.mv_data = (char *)&txn->mt_txnid;
data.mv_data = txn->mt_free_pgs;
/* The free list can still grow during this call,
* despite the pre-emptive touches above. So check
* and make sure the entire thing got written.
*/
do {
i = txn->mt_free_pgs[0];
data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs);
rc = mdb_put0(txn, FREE_DBI, &key, &data, 0);
if (rc) {
mdb_txn_abort(txn);
return rc;
}
} while (i != txn->mt_free_pgs[0]);
}
/* should only be one record now */
if (env->me_pghead) {
MDB_val key, data;
MDB_oldpages *mop;
mop = env->me_pghead;
key.mv_size = sizeof(pgno_t);
key.mv_data = (char *)&mop->mo_txnid;
data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
data.mv_data = mop->mo_pages;
mdb_put0(txn, FREE_DBI, &key, &data, 0);
free(env->me_pghead);
env->me_pghead = NULL;
}
/* Update DB root pointers. Their pages have already been
* touched so this is all in-place and cannot fail.
*/
{
MDB_val data;
data.mv_size = sizeof(MDB_db);
for (i = 2; i < txn->mt_numdbs; i++) {
if (txn->mt_dbxs[i].md_dirty) {
data.mv_data = &txn->mt_dbs[i];
mdb_put0(txn, MAIN_DBI, &txn->mt_dbxs[i].md_name, &data, 0);
}
}
}
/* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
*/
next = 0;
i = 1;
do {
#ifdef _WIN32
/* Windows actually supports scatter/gather I/O, but only on
* unbuffered file handles. Since we're relying on the OS page
* cache for all our data, that's self-defeating. So we just
* write pages one at a time. We use the ov structure to set
* the write offset, to at least save the overhead of a Seek
* system call.
*/
OVERLAPPED ov;
memset(&ov, 0, sizeof(ov));
for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
dp = txn->mt_u.dirty_list[i].mptr;
DPRINTF("committing page %lu", dp->p.mp_pgno);
size = dp->p.mp_pgno * env->me_psize;
ov.Offset = size & 0xffffffff;
ov.OffsetHigh = size >> 16;
ov.OffsetHigh >>= 16;
/* clear dirty flag */
dp->p.mp_flags &= ~P_DIRTY;
rc = WriteFile(env->me_fd, &dp->p, env->me_psize * dp->h.md_num, NULL, &ov);
if (!rc) {
n = ErrCode();
DPRINTF("WriteFile: %d", n);
mdb_txn_abort(txn);
return n;
}
}
done = 1;;
#else
struct iovec iov[MDB_COMMIT_PAGES];
n = 0;
done = 1;
size = 0;
for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
dp = txn->mt_u.dirty_list[i].mptr;
if (dp->p.mp_pgno != next) {
if (n) {
DPRINTF("committing %u dirty pages", n);
rc = writev(env->me_fd, iov, n);
if (rc != size) {
n = ErrCode();
if (rc > 0)
DPUTS("short write, filesystem full?");
else
DPRINTF("writev: %s", strerror(n));
mdb_txn_abort(txn);
return n;
}
n = 0;
size = 0;
}
lseek(env->me_fd, dp->p.mp_pgno * env->me_psize, SEEK_SET);
next = dp->p.mp_pgno;
}
DPRINTF("committing page %lu", dp->p.mp_pgno);
iov[n].iov_len = env->me_psize * dp->h.md_num;
iov[n].iov_base = &dp->p;
size += iov[n].iov_len;
next = dp->p.mp_pgno + dp->h.md_num;
/* clear dirty flag */
dp->p.mp_flags &= ~P_DIRTY;
if (++n >= MDB_COMMIT_PAGES) {
done = 0;
i++;
break;
}
}
if (n == 0)
break;
DPRINTF("committing %u dirty pages", n);
rc = writev(env->me_fd, iov, n);
if (rc != size) {
n = ErrCode();
if (rc > 0)
DPUTS("short write, filesystem full?");
else
DPRINTF("writev: %s", strerror(n));
mdb_txn_abort(txn);
return n;
}
#endif
} while (!done);
/* Drop the dirty pages.
*/
for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
dp = txn->mt_u.dirty_list[i].mptr;
if (dp->h.md_num == 1) {
dp->h.md_parent = (MDB_page *)txn->mt_env->me_dpages;
txn->mt_env->me_dpages = dp;
} else {
free(dp);
}
txn->mt_u.dirty_list[i].mid = 0;
}
txn->mt_u.dirty_list[0].mid = 0;
if ((n = mdb_env_sync(env, 0)) != 0 ||
(n = mdb_env_write_meta(txn)) != MDB_SUCCESS) {
mdb_txn_abort(txn);
return n;
}
done:
env->me_txn = NULL;
/* update the DB tables */
{
int toggle = !env->me_db_toggle;
MDB_db *ip, *jp;
ip = &env->me_dbs[toggle][2];
jp = &txn->mt_dbs[2];
LAZY_RWLOCK_WRLOCK(&env->me_dblock);
for (i = 2; i < txn->mt_numdbs; i++) {
if (ip->md_root != jp->md_root)
*ip = *jp;
ip++; jp++;
}
for (i = 2; i < txn->mt_numdbs; i++) {
if (txn->mt_dbxs[i].md_dirty)
txn->mt_dbxs[i].md_dirty = 0;
}
env->me_db_toggle = toggle;
env->me_numdbs = txn->mt_numdbs;
LAZY_RWLOCK_UNLOCK(&env->me_dblock);
}
UNLOCK_MUTEX_W(env);
free(txn);
return MDB_SUCCESS;
}
static int
mdb_env_read_header(MDB_env *env, MDB_meta *meta)
{
char page[PAGESIZE];
MDB_page *p;
MDB_meta *m;
int rc, err;
/* We don't know the page size yet, so use a minimum value.
*/
#ifdef _WIN32
if (!ReadFile(env->me_fd, page, PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
#else
if ((rc = read(env->me_fd, page, PAGESIZE)) == 0)
#endif
{
return ENOENT;
}
else if (rc != PAGESIZE) {
err = ErrCode();
if (rc > 0)
err = EINVAL;
DPRINTF("read: %s", strerror(err));
return err;
}
p = (MDB_page *)page;
if (!F_ISSET(p->mp_flags, P_META)) {
DPRINTF("page %lu not a meta page", p->mp_pgno);
return EINVAL;
}
m = METADATA(p);
if (m->mm_magic != MDB_MAGIC) {
DPUTS("meta has invalid magic");
return EINVAL;
}
if (m->mm_version != MDB_VERSION) {
DPRINTF("database is version %u, expected version %u",
m->mm_version, MDB_VERSION);
return MDB_VERSION_MISMATCH;
}
memcpy(meta, m, sizeof(*m));
return 0;
}
static int
mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
{
MDB_page *p, *q;
MDB_meta *m;
int rc;
unsigned int psize;
DPUTS("writing new meta page");
GetPageSize(psize);
meta->mm_magic = MDB_MAGIC;
meta->mm_version = MDB_VERSION;
meta->mm_psize = psize;
meta->mm_last_pg = 1;
meta->mm_flags = env->me_flags & 0xffff;
meta->mm_flags |= MDB_INTEGERKEY;
meta->mm_dbs[0].md_root = P_INVALID;
meta->mm_dbs[1].md_root = P_INVALID;
p = calloc(2, psize);
p->mp_pgno = 0;
p->mp_flags = P_META;
m = METADATA(p);
memcpy(m, meta, sizeof(*meta));
q = (MDB_page *)((char *)p + psize);
q->mp_pgno = 1;
q->mp_flags = P_META;
m = METADATA(q);
memcpy(m, meta, sizeof(*meta));
#ifdef _WIN32
{
DWORD len;
rc = WriteFile(env->me_fd, p, psize * 2, &len, NULL);
rc = (len == psize * 2) ? MDB_SUCCESS : ErrCode();
}
#else
rc = write(env->me_fd, p, psize * 2);
rc = (rc == (int)psize * 2) ? MDB_SUCCESS : ErrCode();
#endif
free(p);
return rc;
}
static int
mdb_env_write_meta(MDB_txn *txn)
{
MDB_env *env;
MDB_meta meta, metab;
off_t off;
int rc, len, toggle;
char *ptr;
#ifdef _WIN32
OVERLAPPED ov;
#endif
assert(txn != NULL);
assert(txn->mt_env != NULL);
toggle = !txn->mt_toggle;
DPRINTF("writing meta page %d for root page %lu",
toggle, txn->mt_dbs[MAIN_DBI].md_root);
env = txn->mt_env;
metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
ptr = (char *)&meta;
off = offsetof(MDB_meta, mm_dbs[0].md_depth);
len = sizeof(MDB_meta) - off;
ptr += off;
meta.mm_dbs[0] = txn->mt_dbs[0];
meta.mm_dbs[1] = txn->mt_dbs[1];
meta.mm_last_pg = txn->mt_next_pgno - 1;
meta.mm_txnid = txn->mt_txnid;
if (toggle)
off += env->me_psize;
off += PAGEHDRSZ;
/* Write to the SYNC fd */
#ifdef _WIN32
{
memset(&ov, 0, sizeof(ov));
ov.Offset = off;
WriteFile(env->me_mfd, ptr, len, (DWORD *)&rc, &ov);
}
#else
rc = pwrite(env->me_mfd, ptr, len, off);
#endif
if (rc != len) {
int r2;
rc = ErrCode();
DPUTS("write failed, disk error?");
/* On a failure, the pagecache still contains the new data.
* Write some old data back, to prevent it from being used.
* Use the non-SYNC fd; we know it will fail anyway.
*/
meta.mm_last_pg = metab.mm_last_pg;
meta.mm_txnid = metab.mm_txnid;
#ifdef _WIN32
WriteFile(env->me_fd, ptr, len, NULL, &ov);
#else
r2 = pwrite(env->me_fd, ptr, len, off);
#endif
env->me_flags |= MDB_FATAL_ERROR;
return rc;
}
/* Memory ordering issues are irrelevant; since the entire writer
* is wrapped by wmutex, all of these changes will become visible
* after the wmutex is unlocked. Since the DB is multi-version,
* readers will get consistent data regardless of how fresh or
* how stale their view of these values is.
*/
LAZY_MUTEX_LOCK(&env->me_txns->mti_mutex);
txn->mt_env->me_txns->mti_me_toggle = toggle;
txn->mt_env->me_txns->mti_txnid = txn->mt_txnid;
LAZY_MUTEX_UNLOCK(&env->me_txns->mti_mutex);
return MDB_SUCCESS;
}
static int
mdb_env_read_meta(MDB_env *env, int *which)
{
int toggle = 0;
assert(env != NULL);
if (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid)
toggle = 1;
DPRINTF("Using meta page %d", toggle);
*which = toggle;
return MDB_SUCCESS;
}
int
mdb_env_create(MDB_env **env)
{
MDB_env *e;
e = calloc(1, sizeof(MDB_env));
if (!e) return ENOMEM;
e->me_maxreaders = DEFAULT_READERS;
e->me_maxdbs = 2;
e->me_fd = INVALID_HANDLE_VALUE;
e->me_lfd = INVALID_HANDLE_VALUE;
e->me_mfd = INVALID_HANDLE_VALUE;
*env = e;
return MDB_SUCCESS;
}
int
mdb_env_set_mapsize(MDB_env *env, size_t size)
{
if (env->me_map)
return EINVAL;
env->me_mapsize = size;
return MDB_SUCCESS;
}
int
mdb_env_set_maxdbs(MDB_env *env, int dbs)
{
if (env->me_map)
return EINVAL;
env->me_maxdbs = dbs;
return MDB_SUCCESS;
}
int
mdb_env_set_maxreaders(MDB_env *env, int readers)
{
if (env->me_map)
return EINVAL;
env->me_maxreaders = readers;
return MDB_SUCCESS;
}
int
mdb_env_get_maxreaders(MDB_env *env, int *readers)
{
if (!env || !readers)
return EINVAL;
*readers = env->me_maxreaders;
return MDB_SUCCESS;
}
static int
mdb_env_open2(MDB_env *env, unsigned int flags)
{
int i, newenv = 0, toggle;
MDB_meta meta;
MDB_page *p;
env->me_flags = flags;
memset(&meta, 0, sizeof(meta));
if ((i = mdb_env_read_header(env, &meta)) != 0) {
if (i != ENOENT)
return i;
DPUTS("new mdbenv");
newenv = 1;
}
if (!env->me_mapsize) {
env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
}
#ifdef _WIN32
{
HANDLE mh;
LONG sizelo, sizehi;
sizelo = env->me_mapsize & 0xffffffff;
sizehi = env->me_mapsize >> 16; /* pointless on WIN32, only needed on W64 */
sizehi >>= 16;
/* Windows won't create mappings for zero length files.
* Just allocate the maxsize right now.
*/
if (newenv) {
SetFilePointer(env->me_fd, sizelo, sizehi ? &sizehi : NULL, 0);
if (!SetEndOfFile(env->me_fd))
return ErrCode();
SetFilePointer(env->me_fd, 0, NULL, 0);
}
mh = CreateFileMapping(env->me_fd, NULL, PAGE_READONLY,
sizehi, sizelo, NULL);
if (!mh)
return ErrCode();
env->me_map = MapViewOfFileEx(mh, FILE_MAP_READ, 0, 0, env->me_mapsize,
meta.mm_address);
CloseHandle(mh);
if (!env->me_map)
return ErrCode();
}
#else
i = MAP_SHARED;
if (meta.mm_address && (flags & MDB_FIXEDMAP))
i |= MAP_FIXED;
env->me_map = mmap(meta.mm_address, env->me_mapsize, PROT_READ, i,
env->me_fd, 0);
if (env->me_map == MAP_FAILED)
return ErrCode();
#endif
if (newenv) {
meta.mm_mapsize = env->me_mapsize;
if (flags & MDB_FIXEDMAP)
meta.mm_address = env->me_map;
i = mdb_env_init_meta(env, &meta);
if (i != MDB_SUCCESS) {
munmap(env->me_map, env->me_mapsize);
return i;
}
}
env->me_psize = meta.mm_psize;
env->me_maxpg = env->me_mapsize / env->me_psize;
p = (MDB_page *)env->me_map;
env->me_metas[0] = METADATA(p);
env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize);
if ((i = mdb_env_read_meta(env, &toggle)) != 0)
return i;
DPRINTF("opened database version %u, pagesize %u",
env->me_metas[toggle]->mm_version, env->me_psize);
DPRINTF("depth: %u", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_depth);
DPRINTF("entries: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_entries);
DPRINTF("branch pages: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_branch_pages);
DPRINTF("leaf pages: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_leaf_pages);
DPRINTF("overflow pages: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_overflow_pages);
DPRINTF("root: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_root);
return MDB_SUCCESS;
}
#ifndef _WIN32
/* Windows doesn't support destructor callbacks for thread-specific storage */
static void
mdb_env_reader_dest(void *ptr)
{
MDB_reader *reader = ptr;
reader->mr_txnid = 0;
reader->mr_pid = 0;
reader->mr_tid = 0;
}
#endif
/* downgrade the exclusive lock on the region back to shared */
static void
mdb_env_share_locks(MDB_env *env)
{
int toggle = 0;
if (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid)
toggle = 1;
env->me_txns->mti_me_toggle = toggle;
env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
#ifdef _WIN32
{
OVERLAPPED ov;
/* First acquire a shared lock. The Unlock will
* then release the existing exclusive lock.
*/
memset(&ov, 0, sizeof(ov));
LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov);
UnlockFile(env->me_lfd, 0, 0, 1, 0);
}
#else
{
struct flock lock_info;
/* The shared lock replaces the existing lock */
memset((void *)&lock_info, 0, sizeof(lock_info));
lock_info.l_type = F_RDLCK;
lock_info.l_whence = SEEK_SET;
lock_info.l_start = 0;
lock_info.l_len = 1;
fcntl(env->me_lfd, F_SETLK, &lock_info);
}
#endif
}
static int
mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
{
int rc;
off_t size, rsize;
*excl = 0;
#ifdef _WIN32
if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) {
rc = ErrCode();
return rc;
}
/* Try to get exclusive lock. If we succeed, then
* nobody is using the lock region and we should initialize it.
*/
{
if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
*excl = 1;
} else {
OVERLAPPED ov;
memset(&ov, 0, sizeof(ov));
if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
rc = ErrCode();
goto fail;
}
}
}
size = GetFileSize(env->me_lfd, NULL);
#else
if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
rc = ErrCode();
return rc;
}
/* Try to get exclusive lock. If we succeed, then
* nobody is using the lock region and we should initialize it.
*/
{
struct flock lock_info;
memset((void *)&lock_info, 0, sizeof(lock_info));
lock_info.l_type = F_WRLCK;
lock_info.l_whence = SEEK_SET;
lock_info.l_start = 0;
lock_info.l_len = 1;
rc = fcntl(env->me_lfd, F_SETLK, &lock_info);
if (rc == 0) {
*excl = 1;
} else {
lock_info.l_type = F_RDLCK;
rc = fcntl(env->me_lfd, F_SETLKW, &lock_info);
if (rc) {
rc = ErrCode();
goto fail;
}
}
}
size = lseek(env->me_lfd, 0, SEEK_END);
#endif
rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
if (size < rsize && *excl) {
#ifdef _WIN32
SetFilePointer(env->me_lfd, rsize, NULL, 0);
if (!SetEndOfFile(env->me_lfd)) {
rc = ErrCode();
goto fail;
}
#else
if (ftruncate(env->me_lfd, rsize) != 0) {
rc = ErrCode();
goto fail;
}
#endif
} else {
rsize = size;
size = rsize - sizeof(MDB_txninfo);
env->me_maxreaders = size/sizeof(MDB_reader) + 1;
}
#ifdef _WIN32
{
HANDLE mh;
mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
0, 0, NULL);
if (!mh) {
rc = ErrCode();
goto fail;
}
env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
CloseHandle(mh);
if (!env->me_txns) {
rc = ErrCode();
goto fail;
}
}
#else
env->me_txns = mmap(0, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
env->me_lfd, 0);
if (env->me_txns == MAP_FAILED) {
rc = ErrCode();
goto fail;
}
#endif
if (*excl) {
#ifdef _WIN32
char *ptr;
if (!mdb_sec_inited) {
InitializeSecurityDescriptor(&mdb_null_sd,
SECURITY_DESCRIPTOR_REVISION);
SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
mdb_all_sa.bInheritHandle = FALSE;
mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
mdb_sec_inited = 1;
}
/* FIXME: only using up to 20 characters of the env path here,
* probably not enough to assure uniqueness...
*/
sprintf(env->me_txns->mti_rmname, "Global\\MDBr%.20s", lpath);
ptr = env->me_txns->mti_rmname + sizeof("Global\\MDBr");
while ((ptr = strchr(ptr, '\\')))
*ptr++ = '/';
env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
if (!env->me_rmutex) {
rc = ErrCode();
goto fail;
}
sprintf(env->me_txns->mti_rmname, "Global\\MDBw%.20s", lpath);
ptr = env->me_txns->mti_rmname + sizeof("Global\\MDBw");
while ((ptr = strchr(ptr, '\\')))
*ptr++ = '/';
env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
if (!env->me_wmutex) {
rc = ErrCode();
goto fail;
}
#else
pthread_mutexattr_t mattr;
pthread_mutexattr_init(&mattr);
rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
if (rc) {
goto fail;
}
pthread_mutex_init(&env->me_txns->mti_mutex, &mattr);
pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr);
#endif
env->me_txns->mti_version = MDB_VERSION;
env->me_txns->mti_magic = MDB_MAGIC;
env->me_txns->mti_txnid = 0;
env->me_txns->mti_numreaders = 0;
env->me_txns->mti_me_toggle = 0;
} else {
if (env->me_txns->mti_magic != MDB_MAGIC) {
DPUTS("lock region has invalid magic");
rc = EINVAL;
goto fail;
}
if (env->me_txns->mti_version != MDB_VERSION) {
DPRINTF("lock region is version %u, expected version %u",
env->me_txns->mti_version, MDB_VERSION);
rc = MDB_VERSION_MISMATCH;
goto fail;
}
rc = ErrCode();
if (rc != EACCES && rc != EAGAIN) {
goto fail;
}
#ifdef _WIN32
env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
if (!env->me_rmutex) {
rc = ErrCode();
goto fail;
}
env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
if (!env->me_wmutex) {
rc = ErrCode();
goto fail;
}
#endif
}
return MDB_SUCCESS;
fail:
close(env->me_lfd);
env->me_lfd = INVALID_HANDLE_VALUE;
return rc;
}
#define LOCKNAME "/lock.mdb"
#define DATANAME "/data.mdb"
int
mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
{
int oflags, rc, len, excl;
char *lpath, *dpath;
len = strlen(path);
lpath = malloc(len + sizeof(LOCKNAME) + len + sizeof(DATANAME));
if (!lpath)
return ENOMEM;
dpath = lpath + len + sizeof(LOCKNAME);
sprintf(lpath, "%s" LOCKNAME, path);
sprintf(dpath, "%s" DATANAME, path);
rc = mdb_env_setup_locks(env, lpath, mode, &excl);
if (rc)
goto leave;
#ifdef _WIN32
if (F_ISSET(flags, MDB_RDONLY)) {
oflags = GENERIC_READ;
len = OPEN_EXISTING;
} else {
oflags = GENERIC_READ|GENERIC_WRITE;
len = OPEN_ALWAYS;
}
mode = FILE_ATTRIBUTE_NORMAL;
if ((env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL, len, mode, NULL)) == INVALID_HANDLE_VALUE) {
rc = ErrCode();
goto leave;
}
#else
if (F_ISSET(flags, MDB_RDONLY))
oflags = O_RDONLY;
else
oflags = O_RDWR | O_CREAT;
if ((env->me_fd = open(dpath, oflags, mode)) == -1) {
rc = ErrCode();
goto leave;
}
#endif
if ((rc = mdb_env_open2(env, flags)) == MDB_SUCCESS) {
/* synchronous fd for meta writes */
#ifdef _WIN32
if (!(flags & (MDB_RDONLY|MDB_NOSYNC)))
mode |= FILE_FLAG_WRITE_THROUGH;
if ((env->me_mfd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL, len, mode, NULL)) == INVALID_HANDLE_VALUE) {
rc = ErrCode();
goto leave;
}
#else
if (!(flags & (MDB_RDONLY|MDB_NOSYNC)))
oflags |= MDB_DSYNC;
if ((env->me_mfd = open(dpath, oflags, mode)) == -1) {
rc = ErrCode();
goto leave;
}
#endif
env->me_path = strdup(path);
DPRINTF("opened dbenv %p", (void *) env);
pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
LAZY_RWLOCK_INIT(&env->me_dblock, NULL);
if (excl)
mdb_env_share_locks(env);
env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
env->me_dbs[0] = calloc(env->me_maxdbs, sizeof(MDB_db));
env->me_dbs[1] = calloc(env->me_maxdbs, sizeof(MDB_db));
env->me_numdbs = 2;
}
leave:
if (rc) {
if (env->me_fd != INVALID_HANDLE_VALUE) {
close(env->me_fd);
env->me_fd = INVALID_HANDLE_VALUE;
}
if (env->me_lfd != INVALID_HANDLE_VALUE) {
close(env->me_lfd);
env->me_lfd = INVALID_HANDLE_VALUE;
}
}
free(lpath);
return rc;
}
void
mdb_env_close(MDB_env *env)
{
MDB_dpage *dp;
if (env == NULL)
return;
while (env->me_dpages) {
dp = env->me_dpages;
env->me_dpages = (MDB_dpage *)dp->h.md_parent;
free(dp);
}
free(env->me_dbs[1]);
free(env->me_dbs[0]);
free(env->me_dbxs);
free(env->me_path);
LAZY_RWLOCK_DESTROY(&env->me_dblock);
pthread_key_delete(env->me_txkey);
if (env->me_map) {
munmap(env->me_map, env->me_mapsize);
}
close(env->me_mfd);
close(env->me_fd);
if (env->me_txns) {
pid_t pid = getpid();
unsigned int i;
for (i=0; i<env->me_txns->mti_numreaders; i++)
if (env->me_txns->mti_readers[i].mr_pid == pid)
env->me_txns->mti_readers[i].mr_pid = 0;
munmap(env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
}
close(env->me_lfd);
free(env);
}
/* Search for key within a leaf 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).
* If kip is non-null, stores the index of the found entry in *kip.
* If no entry larger or equal to the key is found, returns NULL.
*/
static MDB_node *
mdb_search_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp, MDB_val *key,
int *exactp, unsigned int *kip)
{
unsigned int i = 0;
int low, high;
int rc = 0;
MDB_node *node = NULL;
MDB_val nodekey;
DKBUF;
DPRINTF("searching %u keys in %s page %lu",
NUMKEYS(mp),
IS_LEAF(mp) ? "leaf" : "branch",
mp->mp_pgno);
assert(NUMKEYS(mp) > 0);
memset(&nodekey, 0, sizeof(nodekey));
low = IS_LEAF(mp) ? 0 : 1;
high = NUMKEYS(mp) - 1;
while (low <= high) {
i = (low + high) >> 1;
if (IS_LEAF2(mp)) {
nodekey.mv_size = txn->mt_dbs[dbi].md_pad;
nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
} else {
node = NODEPTR(mp, i);
nodekey.mv_size = node->mn_ksize;
nodekey.mv_data = NODEKEY(node);
}
rc = mdb_cmp(txn, dbi, key, &nodekey);
if (IS_LEAF(mp))
DPRINTF("found leaf index %u [%s], rc = %i",
i, DKEY(&nodekey), rc);
else
DPRINTF("found branch index %u [%s -> %lu], rc = %i",
i, DKEY(&nodekey), NODEPGNO(node), rc);
if (rc == 0)
break;
if (rc > 0)
low = i + 1;
else
high = i - 1;
}
if (rc > 0) { /* Found entry is less than the key. */
i++; /* Skip to get the smallest entry larger than key. */
if (i >= NUMKEYS(mp))
/* There is no entry larger or equal to the key. */
return NULL;
}
if (exactp)
*exactp = (rc == 0);
if (kip) /* Store the key index if requested. */
*kip = i;
/* nodeptr is fake for LEAF2 */
return IS_LEAF2(mp) ? NODEPTR(mp, 0) : NODEPTR(mp, i);
}
static void
cursor_pop_page(MDB_cursor *cursor)
{
MDB_ppage *top;
if (cursor->mc_snum) {
top = CURSOR_TOP(cursor);
cursor->mc_snum--;
DPRINTF("popped page %lu off db %u cursor %p", top->mp_page->mp_pgno,
cursor->mc_dbi, (void *) cursor);
}
}
static MDB_ppage *
cursor_push_page(MDB_cursor *cursor, MDB_page *mp)
{
MDB_ppage *ppage;
DPRINTF("pushing page %lu on db %u cursor %p", mp->mp_pgno,
cursor->mc_dbi, (void *) cursor);
assert(cursor->mc_snum < CURSOR_STACK);
ppage = &cursor->mc_stack[cursor->mc_snum++];
ppage->mp_page = mp;
ppage->mp_ki = 0;
return ppage;
}
static int
mdb_get_page(MDB_txn *txn, pgno_t pgno, MDB_page **ret)
{
MDB_page *p = NULL;
if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) {
MDB_dpage *dp;
unsigned x;
x = mdb_mid2l_search(txn->mt_u.dirty_list, pgno);
if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) {
dp = txn->mt_u.dirty_list[x].mptr;
p = &dp->p;
}
}
if (!p) {
if (pgno <= txn->mt_env->me_metas[txn->mt_toggle]->mm_last_pg)
p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
}
*ret = p;
if (!p) {
DPRINTF("page %lu not found", pgno);
assert(p != NULL);
}
return (p != NULL) ? MDB_SUCCESS : MDB_PAGE_NOTFOUND;
}
static int
mdb_search_page_root(MDB_txn *txn, MDB_dbi dbi, MDB_val *key,
MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
{
MDB_page *mp = mpp->mp_page;
DKBUF;
int rc;
if (cursor && cursor_push_page(cursor, mp) == NULL)
return ENOMEM;
while (IS_BRANCH(mp)) {
unsigned int i = 0;
MDB_node *node;
DPRINTF("branch page %lu has %u keys", mp->mp_pgno, NUMKEYS(mp));
assert(NUMKEYS(mp) > 1);
DPRINTF("found index 0 to page %lu", NODEPGNO(NODEPTR(mp, 0)));
if (key == NULL) /* Initialize cursor to first page. */
i = 0;
else if (key->mv_size > MAXKEYSIZE && key->mv_data == NULL) {
/* cursor to last page */
i = NUMKEYS(mp)-1;
} else {
int exact;
node = mdb_search_node(txn, dbi, mp, key, &exact, &i);
if (node == NULL)
i = NUMKEYS(mp) - 1;
else if (!exact) {
assert(i > 0);
i--;
}
}
if (key)
DPRINTF("following index %u for key [%s]",
i, DKEY(key));
assert(i < NUMKEYS(mp));
node = NODEPTR(mp, i);
if (cursor)
CURSOR_TOP(cursor)->mp_ki = i;
mpp->mp_parent = mp;
if ((rc = mdb_get_page(txn, NODEPGNO(node), &mp)))
return rc;
mpp->mp_pi = i;
mpp->mp_page = mp;
if (cursor && cursor_push_page(cursor, mp) == NULL)
return ENOMEM;
if (modify) {
MDB_dhead *dh = ((MDB_dhead *)mp)-1;
if ((rc = mdb_touch(txn, dbi, mpp)) != 0)
return rc;
dh = ((MDB_dhead *)mpp->mp_page)-1;
dh->md_parent = mpp->mp_parent;
dh->md_pi = mpp->mp_pi;
}
mp = mpp->mp_page;
}
if (!IS_LEAF(mp)) {
DPRINTF("internal error, index points to a %02X page!?",
mp->mp_flags);
return MDB_CORRUPTED;
}
DPRINTF("found leaf page %lu for key [%s]", mp->mp_pgno,
key ? DKEY(key) : NULL);
return MDB_SUCCESS;
}
/* Search for the page a given key should be in.
* Stores a pointer to the found page in *mpp.
* If key is NULL, search for the lowest page (used by mdb_cursor_first).
* If cursor is non-null, pushes parent pages on the cursor stack.
* If modify is true, visited pages are updated with new page numbers.
*/
static int
mdb_search_page(MDB_txn *txn, MDB_dbi dbi, MDB_val *key,
MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
{
int rc;
pgno_t root;
/* Choose which root page to start with. If a transaction is given
* use the root page from the transaction, otherwise read the last
* committed root page.
*/
if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
DPUTS("transaction has failed, must abort");
return EINVAL;
} else
root = txn->mt_dbs[dbi].md_root;
if (root == P_INVALID) { /* Tree is empty. */
DPUTS("tree is empty");
return MDB_NOTFOUND;
}
if ((rc = mdb_get_page(txn, root, &mpp->mp_page)))
return rc;
DPRINTF("db %u root page %lu has flags 0x%X",
dbi, root, mpp->mp_page->mp_flags);
if (modify) {
/* For sub-databases, update main root first */
if (dbi > MAIN_DBI && !txn->mt_dbxs[dbi].md_dirty) {
MDB_pageparent mp2;
rc = mdb_search_page(txn, MAIN_DBI, &txn->mt_dbxs[dbi].md_name,
NULL, 1, &mp2);
if (rc)
return rc;
txn->mt_dbxs[dbi].md_dirty = 1;
}
if (!F_ISSET(mpp->mp_page->mp_flags, P_DIRTY)) {
mpp->mp_parent = NULL;
mpp->mp_pi = 0;
if ((rc = mdb_touch(txn, dbi, mpp)))
return rc;
txn->mt_dbs[dbi].md_root = mpp->mp_page->mp_pgno;
}
}
return mdb_search_page_root(txn, dbi, key, cursor, modify, mpp);
}
static int
mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
{
MDB_page *omp; /* overflow mpage */
pgno_t pgno;
int rc;
if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
data->mv_size = leaf->mn_dsize;
data->mv_data = NODEDATA(leaf);
return MDB_SUCCESS;
}
/* Read overflow data.
*/
data->mv_size = leaf->mn_dsize;
memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
if ((rc = mdb_get_page(txn, pgno, &omp))) {
DPRINTF("read overflow page %lu failed", pgno);
return rc;
}
data->mv_data = METADATA(omp);
return MDB_SUCCESS;
}
int
mdb_get(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data)
{
MDB_cursor mc;
MDB_xcursor mx;
int exact;
DKBUF;
assert(key);
assert(data);
DPRINTF("===> get db %u key [%s]", dbi, DKEY(key));
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
return EINVAL;
}
mc.mc_txn = txn;
mc.mc_dbi = dbi;
mc.mc_flags = 0;
if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
mc.mc_xcursor = &mx;
mdb_xcursor_init0(&mc);
} else {
mc.mc_xcursor = NULL;
}
return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
}
static int
mdb_sibling(MDB_cursor *cursor, int move_right)
{
int rc;
MDB_node *indx;
MDB_ppage *parent;
MDB_page *mp;
if (cursor->mc_snum < 2) {
return MDB_NOTFOUND; /* root has no siblings */
}
parent = CURSOR_PARENT(cursor);
DPRINTF("parent page is page %lu, index %u",
parent->mp_page->mp_pgno, parent->mp_ki);
cursor_pop_page(cursor);
if (move_right ? (parent->mp_ki + 1 >= NUMKEYS(parent->mp_page))
: (parent->mp_ki == 0)) {
DPRINTF("no more keys left, moving to %s sibling",
move_right ? "right" : "left");
if ((rc = mdb_sibling(cursor, move_right)) != MDB_SUCCESS)
return rc;
parent = CURSOR_TOP(cursor);
} else {
if (move_right)
parent->mp_ki++;
else
parent->mp_ki--;
DPRINTF("just moving to %s index key %u",
move_right ? "right" : "left", parent->mp_ki);
}
assert(IS_BRANCH(parent->mp_page));
indx = NODEPTR(parent->mp_page, parent->mp_ki);
if ((rc = mdb_get_page(cursor->mc_txn, NODEPGNO(indx), &mp)))
return rc;;
#if 0
mp->parent = parent->mp_page;
mp->parent_index = parent->mp_ki;
#endif
cursor_push_page(cursor, mp);
return MDB_SUCCESS;
}
static int
mdb_cursor_next(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op op)
{
MDB_ppage *top;
MDB_page *mp;
MDB_node *leaf;
int rc;
if (cursor->mc_flags & C_EOF) {
return MDB_NOTFOUND;
}
assert(cursor->mc_flags & C_INITIALIZED);
top = CURSOR_TOP(cursor);
mp = top->mp_page;
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
leaf = NODEPTR(mp, top->mp_ki);
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
rc = mdb_cursor_next(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
if (op != MDB_NEXT || rc == MDB_SUCCESS)
return rc;
}
} else {
cursor->mc_xcursor->mx_cursor.mc_flags = 0;
if (op == MDB_NEXT_DUP)
return MDB_NOTFOUND;
}
}
DPRINTF("cursor_next: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
if (top->mp_ki + 1 >= NUMKEYS(mp)) {
DPUTS("=====> move to next sibling page");
if (mdb_sibling(cursor, 1) != MDB_SUCCESS) {
cursor->mc_flags |= C_EOF;
return MDB_NOTFOUND;
}
top = CURSOR_TOP(cursor);
mp = top->mp_page;
DPRINTF("next page is %lu, key index %u", mp->mp_pgno, top->mp_ki);
} else
top->mp_ki++;
DPRINTF("==> cursor points to page %lu with %u keys, key index %u",
mp->mp_pgno, NUMKEYS(mp), top->mp_ki);
if (IS_LEAF2(mp)) {
key->mv_size = cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_pad;
key->mv_data = LEAF2KEY(mp, top->mp_ki, key->mv_size);
return MDB_SUCCESS;
}
assert(IS_LEAF(mp));
leaf = NODEPTR(mp, top->mp_ki);
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, mp, leaf);
}
if (data) {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
return rc;
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc != MDB_SUCCESS)
return rc;
}
}
MDB_SET_KEY(leaf, key);
return MDB_SUCCESS;
}
static int
mdb_cursor_prev(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op op)
{
MDB_ppage *top;
MDB_page *mp;
MDB_node *leaf;
int rc;
assert(cursor->mc_flags & C_INITIALIZED);
top = CURSOR_TOP(cursor);
mp = top->mp_page;
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
leaf = NODEPTR(mp, top->mp_ki);
if (op == MDB_PREV || op == MDB_PREV_DUP) {
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
rc = mdb_cursor_prev(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
if (op != MDB_PREV || rc == MDB_SUCCESS)
return rc;
} else {
cursor->mc_xcursor->mx_cursor.mc_flags = 0;
if (op == MDB_PREV_DUP)
return MDB_NOTFOUND;
}
}
}
DPRINTF("cursor_prev: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
if (top->mp_ki == 0) {
DPUTS("=====> move to prev sibling page");
if (mdb_sibling(cursor, 0) != MDB_SUCCESS) {
cursor->mc_flags &= ~C_INITIALIZED;
return MDB_NOTFOUND;
}
top = CURSOR_TOP(cursor);
mp = top->mp_page;
top->mp_ki = NUMKEYS(mp) - 1;
DPRINTF("prev page is %lu, key index %u", mp->mp_pgno, top->mp_ki);
} else
top->mp_ki--;
cursor->mc_flags &= ~C_EOF;
DPRINTF("==> cursor points to page %lu with %u keys, key index %u",
mp->mp_pgno, NUMKEYS(mp), top->mp_ki);
if (IS_LEAF2(mp)) {
key->mv_size = cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_pad;
key->mv_data = LEAF2KEY(mp, top->mp_ki, key->mv_size);
return MDB_SUCCESS;
}
assert(IS_LEAF(mp));
leaf = NODEPTR(mp, top->mp_ki);
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, mp, leaf);
}
if (data) {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
return rc;
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc != MDB_SUCCESS)
return rc;
}
}
MDB_SET_KEY(leaf, key);
return MDB_SUCCESS;
}
static int
mdb_cursor_set(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
MDB_cursor_op op, int *exactp)
{
int rc;
MDB_node *leaf;
MDB_ppage *top;
MDB_pageparent mpp;
DKBUF;
assert(cursor);
assert(key);
assert(key->mv_size > 0);
/* See if we're already on the right page */
if (cursor->mc_flags & C_INITIALIZED) {
MDB_val nodekey;
top = CURSOR_TOP(cursor);
/* Don't try this for LEAF2 pages. Maybe support that later. */
if ((top->mp_page->mp_flags & (P_LEAF|P_LEAF2)) == P_LEAF) {
leaf = NODEPTR(top->mp_page, 0);
MDB_SET_KEY(leaf, &nodekey);
rc = mdb_cmp(cursor->mc_txn, cursor->mc_dbi, key, &nodekey);
if (rc >= 0) {
leaf = NODEPTR(top->mp_page, NUMKEYS(top->mp_page)-1);
MDB_SET_KEY(leaf, &nodekey);
rc = mdb_cmp(cursor->mc_txn, cursor->mc_dbi, key, &nodekey);
if (rc <= 0) {
/* we're already on the right page */
mpp.mp_page = top->mp_page;
rc = 0;
goto set2;
}
}
}
}
cursor->mc_snum = 0;
rc = mdb_search_page(cursor->mc_txn, cursor->mc_dbi, key, cursor, 0, &mpp);
if (rc != MDB_SUCCESS)
return rc;
assert(IS_LEAF(mpp.mp_page));
top = CURSOR_TOP(cursor);
set2:
leaf = mdb_search_node(cursor->mc_txn, cursor->mc_dbi, mpp.mp_page, key, exactp, &top->mp_ki);
if (exactp != NULL && !*exactp) {
/* MDB_SET specified and not an exact match. */
return MDB_NOTFOUND;
}
if (leaf == NULL) {
DPUTS("===> inexact leaf not found, goto sibling");
if ((rc = mdb_sibling(cursor, 1)) != MDB_SUCCESS)
return rc; /* no entries matched */
top = CURSOR_TOP(cursor);
top->mp_ki = 0;
mpp.mp_page = top->mp_page;
assert(IS_LEAF(mpp.mp_page));
leaf = NODEPTR(mpp.mp_page, 0);
}
cursor->mc_flags |= C_INITIALIZED;
cursor->mc_flags &= ~C_EOF;
if (IS_LEAF2(mpp.mp_page)) {
key->mv_size = cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_pad;
key->mv_data = LEAF2KEY(mpp.mp_page, top->mp_ki, key->mv_size);
return MDB_SUCCESS;
}
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, mpp.mp_page, leaf);
}
if (data) {
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
if (op == MDB_SET || op == MDB_SET_RANGE) {
rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
} else {
int ex2, *ex2p;
if (op == MDB_GET_BOTH) {
ex2p = &ex2;
ex2 = 0;
} else {
ex2p = NULL;
}
rc = mdb_cursor_set(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
if (rc != MDB_SUCCESS)
return rc;
}
} else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
MDB_val d2;
if ((rc = mdb_read_data(cursor->mc_txn, leaf, &d2)) != MDB_SUCCESS)
return rc;
rc = mdb_dcmp(cursor->mc_txn, cursor->mc_dbi, data, &d2);
if (rc) {
if (op == MDB_GET_BOTH || rc > 0)
return MDB_NOTFOUND;
}
} else {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
}
}
/* The key already matches in all other cases */
if (op == MDB_SET_RANGE)
MDB_SET_KEY(leaf, key);
DPRINTF("==> cursor placed on key [%s]", DKEY(key));
return rc;
}
static int
mdb_cursor_first(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
{
int rc;
MDB_pageparent mpp;
MDB_node *leaf;
cursor->mc_snum = 0;
rc = mdb_search_page(cursor->mc_txn, cursor->mc_dbi, NULL, cursor, 0, &mpp);
if (rc != MDB_SUCCESS)
return rc;
assert(IS_LEAF(mpp.mp_page));
leaf = NODEPTR(mpp.mp_page, 0);
cursor->mc_flags |= C_INITIALIZED;
cursor->mc_flags &= ~C_EOF;
if (IS_LEAF2(mpp.mp_page)) {
key->mv_size = cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_pad;
key->mv_data = LEAF2KEY(mpp.mp_page, 0, key->mv_size);
return MDB_SUCCESS;
}
if (data) {
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, mpp.mp_page, leaf);
rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc)
return rc;
} else {
if (cursor->mc_xcursor)
cursor->mc_xcursor->mx_cursor.mc_flags = 0;
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
}
}
MDB_SET_KEY(leaf, key);
return MDB_SUCCESS;
}
static int
mdb_cursor_last(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
{
int rc;
MDB_ppage *top;
MDB_pageparent mpp;
MDB_node *leaf;
MDB_val lkey;
cursor->mc_snum = 0;
lkey.mv_size = MAXKEYSIZE+1;
lkey.mv_data = NULL;
rc = mdb_search_page(cursor->mc_txn, cursor->mc_dbi, &lkey, cursor, 0, &mpp);
if (rc != MDB_SUCCESS)
return rc;
assert(IS_LEAF(mpp.mp_page));
leaf = NODEPTR(mpp.mp_page, NUMKEYS(mpp.mp_page)-1);
cursor->mc_flags |= C_INITIALIZED;
cursor->mc_flags &= ~C_EOF;
top = CURSOR_TOP(cursor);
top->mp_ki = NUMKEYS(top->mp_page) - 1;
if (IS_LEAF2(mpp.mp_page)) {
key->mv_size = cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_pad;
key->mv_data = LEAF2KEY(mpp.mp_page, top->mp_ki, key->mv_size);
return MDB_SUCCESS;
}
if (data) {
if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, mpp.mp_page, leaf);
rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc)
return rc;
} else {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
}
}
MDB_SET_KEY(leaf, key);
return MDB_SUCCESS;
}
int
mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
MDB_cursor_op op)
{
int rc;
int exact = 0;
assert(cursor);
switch (op) {
case MDB_GET_BOTH:
case MDB_GET_BOTH_RANGE:
if (data == NULL || cursor->mc_xcursor == NULL) {
rc = EINVAL;
break;
}
/* FALLTHRU */
case MDB_SET:
case MDB_SET_RANGE:
if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
rc = EINVAL;
} else if (op == MDB_SET_RANGE)
rc = mdb_cursor_set(cursor, key, data, op, NULL);
else
rc = mdb_cursor_set(cursor, key, data, op, &exact);
break;
case MDB_GET_MULTIPLE:
if (data == NULL ||
!(cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPFIXED) ||
!(cursor->mc_flags & C_INITIALIZED)) {
rc = EINVAL;
break;
}
rc = MDB_SUCCESS;
if (!(cursor->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
(cursor->mc_xcursor->mx_cursor.mc_flags & C_EOF))
break;
goto fetchm;
case MDB_NEXT_MULTIPLE:
if (data == NULL ||
!(cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPFIXED)) {
rc = EINVAL;
break;
}
if (!(cursor->mc_flags & C_INITIALIZED))
rc = mdb_cursor_first(cursor, key, data);
else
rc = mdb_cursor_next(cursor, key, data, MDB_NEXT_DUP);
if (rc == MDB_SUCCESS) {
if (cursor->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
MDB_ppage *top;
fetchm:
top = CURSOR_TOP(&cursor->mc_xcursor->mx_cursor);
data->mv_size = NUMKEYS(top->mp_page) *
cursor->mc_xcursor->mx_txn.mt_dbs[cursor->mc_xcursor->mx_cursor.mc_dbi].md_pad;
data->mv_data = METADATA(top->mp_page);
top->mp_ki = NUMKEYS(top->mp_page)-1;
} else {
rc = MDB_NOTFOUND;
}
}
break;
case MDB_NEXT:
case MDB_NEXT_DUP:
case MDB_NEXT_NODUP:
if (!(cursor->mc_flags & C_INITIALIZED))
rc = mdb_cursor_first(cursor, key, data);
else
rc = mdb_cursor_next(cursor, key, data, op);
break;
case MDB_PREV:
case MDB_PREV_DUP:
case MDB_PREV_NODUP:
if (!(cursor->mc_flags & C_INITIALIZED) || (cursor->mc_flags & C_EOF))
rc = mdb_cursor_last(cursor, key, data);
else
rc = mdb_cursor_prev(cursor, key, data, op);
break;
case MDB_FIRST:
rc = mdb_cursor_first(cursor, key, data);
break;
case MDB_FIRST_DUP:
if (data == NULL ||
!(cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) ||
!(cursor->mc_flags & C_INITIALIZED) ||
!(cursor->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
rc = EINVAL;
break;
}
rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
break;
case MDB_LAST:
rc = mdb_cursor_last(cursor, key, data);
break;
case MDB_LAST_DUP:
if (data == NULL ||
!(cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) ||
!(cursor->mc_flags & C_INITIALIZED) ||
!(cursor->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
rc = EINVAL;
break;
}
rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
break;
default:
DPRINTF("unhandled/unimplemented cursor operation %u", op);
rc = EINVAL;
break;
}
return rc;
}
static int
mdb_cursor_touch(MDB_cursor *cursor)
{
MDB_pageparent mpp;
unsigned int i;
int rc;
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
for(i=0; i<cursor->mc_snum; i++) {
mpp.mp_page = cursor->mc_stack[i].mp_page;
if (!F_ISSET(mpp.mp_page->mp_flags, P_DIRTY)) {
rc = mdb_touch(cursor->mc_txn, cursor->mc_dbi, &mpp);
if (rc) return rc;
cursor->mc_stack[i].mp_page = mpp.mp_page;
}
mpp.mp_parent = mpp.mp_page;
mpp.mp_pi = cursor->mc_stack[i].mp_ki;
}
return MDB_SUCCESS;
}
int
mdb_cursor_put(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
unsigned int flags)
{
MDB_ppage *top;
MDB_node *leaf;
int rc, exact;
if (F_ISSET(cursor->mc_txn->mt_flags, MDB_TXN_RDONLY))
return EACCES;
if (flags == MDB_NODUPDATA) {
rc = mdb_cursor_set(cursor, key, data, MDB_GET_BOTH, &exact);
if (rc == 0)
return MDB_KEYEXIST;
if (rc != MDB_NOTFOUND)
return rc;
} else if (flags != MDB_CURRENT) {
rc = mdb_cursor_set(cursor, key, NULL, MDB_SET, &exact);
if (flags == MDB_NOOVERWRITE && rc == 0)
return MDB_KEYEXIST;
if (rc != MDB_NOTFOUND)
return rc;
} else if (!(cursor->mc_flags & C_INITIALIZED)) {
return EINVAL;
}
/* Cursor is positioned, now make sure all pages are writable */
rc = mdb_cursor_touch(cursor);
if (rc) return rc;
if (cursor->mc_xcursor) {
rc = mdb_cursor_touch(&cursor->mc_xcursor->mx_cursor);
if (rc) return rc;
cursor->mc_flags |= C_XDIRTY;
}
top = CURSOR_TOP(cursor);
return rc;
}
int
mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
{
MDB_pageparent mpp;
MDB_ppage *top;
MDB_node *leaf;
int rc;
if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
return EACCES;
if (!mc->mc_flags & C_INITIALIZED)
return EINVAL;
rc = mdb_cursor_touch(mc);
if (rc) return rc;
if (mc->mc_xcursor) {
rc = mdb_cursor_touch(&mc->mc_xcursor->mx_cursor);
if (rc) return rc;
}
top = CURSOR_TOP(mc);
leaf = NODEPTR(top->mp_page, top->mp_ki);
if (!IS_LEAF2(top->mp_page) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
MDB_pageparent mp2;
if (flags != MDB_NODUPDATA) {
rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, 0);
mdb_xcursor_fini(mc);
/* If sub-DB still has entries, we're done */
if (mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi].md_root
!= P_INVALID) {
memcpy(NODEDATA(leaf),
&mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi],
sizeof(MDB_db));
mc->mc_txn->mt_dbs[mc->mc_dbi].md_entries--;
return rc;
}
/* otherwise fall thru and delete the sub-DB */
} else {
/* add all the child DB's pages to the free list */
rc = mdb_search_page(&mx.mx_txn, mx.mx_cursor.mc_dbi,
NULL, &mx.mx_cursor, 0, &mp2);
if (rc == MDB_SUCCESS) {
MDB_ppage *top, *parent;
MDB_node *ni;
unsigned int i;
cursor_pop_page(&mx.mx_cursor);
if (mx.mx_cursor.mc_snum) {
top = CURSOR_TOP(&mx.mx_cursor);
while (mx.mx_cursor.mc_snum > 1) {
parent = CURSOR_PARENT(&mx.mx_cursor);
for (i=0; i<NUMKEYS(top->mp_page); i++) {
ni = NODEPTR(top->mp_page, i);
mdb_midl_insert(txn->mt_free_pgs, NODEPGNO(ni));
}
parent->mp_ki++;
if (parent->mp_ki >= NUMKEYS(parent->mp_page)) {
cursor_pop_page(&mx.mx_cursor);
top = parent;
} else {
ni = NODEPTR(parent->mp_page, parent->mp_ki);
rc = mdb_get_page(&mx.mx_txn, NODEPGNO(ni), &top->mp_page);
}
}
}
mdb_midl_insert(txn->mt_free_pgs, mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi].md_root);
}
}
}
return mdb_del0(txn, dbi, ki, &mpp, leaf);
return rc;
}
/* Allocate a page and initialize it
*/
static MDB_dpage *
mdb_new_page(MDB_txn *txn, MDB_dbi dbi, uint32_t flags, int num)
{
MDB_dpage *dp;
if ((dp = mdb_alloc_page(txn, dbi, NULL, 0, num)) == NULL)
return NULL;
DPRINTF("allocated new mpage %lu, page size %u",
dp->p.mp_pgno, txn->mt_env->me_psize);
dp->p.mp_flags = flags | P_DIRTY;
dp->p.mp_lower = PAGEHDRSZ;
dp->p.mp_upper = txn->mt_env->me_psize;
if (IS_BRANCH(&dp->p))
txn->mt_dbs[dbi].md_branch_pages++;
else if (IS_LEAF(&dp->p))
txn->mt_dbs[dbi].md_leaf_pages++;
else if (IS_OVERFLOW(&dp->p)) {
txn->mt_dbs[dbi].md_overflow_pages += num;
dp->p.mp_pages = num;
}
return dp;
}
static size_t
mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
{
size_t sz;
sz = LEAFSIZE(key, data);
if (data->mv_size >= env->me_psize / MDB_MINKEYS) {
/* put on overflow page */
sz -= data->mv_size - sizeof(pgno_t);
}
return sz + sizeof(indx_t);
}
static size_t
mdb_branch_size(MDB_env *env, MDB_val *key)
{
size_t sz;
sz = INDXSIZE(key);
if (sz >= env->me_psize / MDB_MINKEYS) {
/* put on overflow page */
/* not implemented */
/* sz -= key->size - sizeof(pgno_t); */
}
return sz + sizeof(indx_t);
}
static int
mdb_add_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp, indx_t indx,
MDB_val *key, MDB_val *data, pgno_t pgno, uint8_t flags)
{
unsigned int i;
size_t node_size = NODESIZE;
indx_t ofs;
MDB_node *node;
MDB_dpage *ofp = NULL; /* overflow page */
DKBUF;
assert(mp->mp_upper >= mp->mp_lower);
DPRINTF("add to %s page %lu index %i, data size %zu key size %zu [%s]",
IS_LEAF(mp) ? "leaf" : "branch",
mp->mp_pgno, indx, data ? data->mv_size : 0,
key ? key->mv_size : 0, key ? DKEY(key) : NULL);
if (IS_LEAF2(mp)) {
/* Move higher keys up one slot. */
int ksize = txn->mt_dbs[dbi].md_pad, dif;
char *ptr = LEAF2KEY(mp, indx, ksize);
dif = NUMKEYS(mp) - indx;
if (dif > 0)
memmove(ptr+ksize, ptr, dif*ksize);
/* insert new key */
memcpy(ptr, key->mv_data, ksize);
/* Just using these for counting */
mp->mp_lower += sizeof(indx_t);
mp->mp_upper -= ksize - sizeof(indx_t);
return MDB_SUCCESS;
}
if (key != NULL)
node_size += key->mv_size;
if (IS_LEAF(mp)) {
assert(data);
if (F_ISSET(flags, F_BIGDATA)) {
/* Data already on overflow page. */
node_size += sizeof(pgno_t);
} else if (data->mv_size >= txn->mt_env->me_psize / MDB_MINKEYS) {
int ovpages = OVPAGES(data->mv_size, txn->mt_env->me_psize);
/* Put data on overflow page. */
DPRINTF("data size is %zu, put on overflow page",
data->mv_size);
node_size += sizeof(pgno_t);
if ((ofp = mdb_new_page(txn, dbi, P_OVERFLOW, ovpages)) == NULL)
return ENOMEM;
DPRINTF("allocated overflow page %lu", ofp->p.mp_pgno);
flags |= F_BIGDATA;
} else {
node_size += data->mv_size;
}
}
if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
DPRINTF("not enough room in page %lu, got %u ptrs",
mp->mp_pgno, NUMKEYS(mp));
DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
mp->mp_upper - mp->mp_lower);
DPRINTF("node size = %zu", node_size);
return ENOSPC;
}
/* Move higher pointers up one slot. */
for (i = NUMKEYS(mp); i > indx; i--)
mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
/* Adjust free space offsets. */
ofs = mp->mp_upper - node_size;
assert(ofs >= mp->mp_lower + sizeof(indx_t));
mp->mp_ptrs[indx] = ofs;
mp->mp_upper = ofs;
mp->mp_lower += sizeof(indx_t);
/* Write the node data. */
node = NODEPTR(mp, indx);
node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
node->mn_flags = flags;
if (IS_LEAF(mp))
node->mn_dsize = data->mv_size;
else
NODEPGNO(node) = pgno;
if (key)
memcpy(NODEKEY(node), key->mv_data, key->mv_size);
if (IS_LEAF(mp)) {
assert(key);
if (ofp == NULL) {
if (F_ISSET(flags, F_BIGDATA))
memcpy(node->mn_data + key->mv_size, data->mv_data,
sizeof(pgno_t));
else
memcpy(node->mn_data + key->mv_size, data->mv_data,
data->mv_size);
} else {
memcpy(node->mn_data + key->mv_size, &ofp->p.mp_pgno,
sizeof(pgno_t));
memcpy(METADATA(&ofp->p), data->mv_data, data->mv_size);
}
}
return MDB_SUCCESS;
}
static void
mdb_del_node(MDB_page *mp, indx_t indx, int ksize)
{
unsigned int sz;
indx_t i, j, numkeys, ptr;
MDB_node *node;
char *base;
DPRINTF("delete node %u on %s page %lu", indx,
IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno);
assert(indx < NUMKEYS(mp));
if (IS_LEAF2(mp)) {
int x = NUMKEYS(mp) - 1 - indx;
base = LEAF2KEY(mp, indx, ksize);
if (x)
memmove(base, base + ksize, x * ksize);
mp->mp_lower -= sizeof(indx_t);
mp->mp_upper += ksize - sizeof(indx_t);
return;
}
node = NODEPTR(mp, indx);
sz = NODESIZE + node->mn_ksize;
if (IS_LEAF(mp)) {
if (F_ISSET(node->mn_flags, F_BIGDATA))
sz += sizeof(pgno_t);
else
sz += NODEDSZ(node);
}
ptr = mp->mp_ptrs[indx];
numkeys = NUMKEYS(mp);
for (i = j = 0; i < numkeys; i++) {
if (i != indx) {
mp->mp_ptrs[j] = mp->mp_ptrs[i];
if (mp->mp_ptrs[i] < ptr)
mp->mp_ptrs[j] += sz;
j++;
}
}
base = (char *)mp + mp->mp_upper;
memmove(base + sz, base, ptr - mp->mp_upper);
mp->mp_lower -= sizeof(indx_t);
mp->mp_upper += sz;
}
static void
mdb_xcursor_init0(MDB_cursor *mc)
{
MDB_xcursor *mx = mc->mc_xcursor;
MDB_dbi dbn;
mx->mx_txn = *mc->mc_txn;
mx->mx_txn.mt_dbxs = mx->mx_dbxs;
mx->mx_txn.mt_dbs = mx->mx_dbs;
mx->mx_dbxs[0] = mc->mc_txn->mt_dbxs[0];
mx->mx_dbxs[1] = mc->mc_txn->mt_dbxs[1];
if (mc->mc_dbi > 1) {
mx->mx_dbxs[2] = mc->mc_txn->mt_dbxs[mc->mc_dbi];
dbn = 2;
} else {
dbn = 1;
}
mx->mx_dbxs[dbn+1].md_parent = dbn;
mx->mx_dbxs[dbn+1].md_cmp = mx->mx_dbxs[dbn].md_dcmp;
mx->mx_dbxs[dbn+1].md_rel = mx->mx_dbxs[dbn].md_rel;
mx->mx_dbxs[dbn+1].md_dirty = 0;
mx->mx_txn.mt_numdbs = dbn+2;
mx->mx_cursor.mc_snum = 0;
mx->mx_cursor.mc_txn = &mx->mx_txn;
mx->mx_cursor.mc_dbi = dbn+1;
}
static void
mdb_xcursor_init1(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx, MDB_page *mp, MDB_node *node)
{
MDB_db *db = NODEDATA(node);
MDB_dbi dbn;
mx->mx_dbs[0] = txn->mt_dbs[0];
mx->mx_dbs[1] = txn->mt_dbs[1];
if (dbi > 1) {
mx->mx_dbs[2] = txn->mt_dbs[dbi];
dbn = 3;
} else {
dbn = 2;
}
DPRINTF("Sub-db %u for db %u root page %lu", dbn, dbi, db->md_root);
mx->mx_dbs[dbn] = *db;
if (F_ISSET(mp->mp_flags, P_DIRTY))
mx->mx_dbxs[dbn].md_dirty = 1;
mx->mx_dbxs[dbn].md_name.mv_data = NODEKEY(node);
mx->mx_dbxs[dbn].md_name.mv_size = node->mn_ksize;
mx->mx_txn.mt_next_pgno = txn->mt_next_pgno;
mx->mx_txn.mt_u = txn->mt_u;
mx->mx_cursor.mc_flags = 0;
}
static void
mdb_xcursor_fini(MDB_cursor *mc)
{
MDB_xcursor *mx = mc->mc_xcursor;
mc->mc_txn->mt_next_pgno = mx->mx_txn.mt_next_pgno;
mc->mc_txn->mt_u = mx->mx_txn.mt_u;
mc->mc_txn->mt_dbs[0] = mx->mx_dbs[0];
mc->mc_txn->mt_dbs[1] = mx->mx_dbs[1];
mc->mc_txn->mt_dbxs[0].md_dirty = mx->mx_dbxs[0].md_dirty;
mc->mc_txn->mt_dbxs[1].md_dirty = mx->mx_dbxs[1].md_dirty;
if (mc->mc_dbi > 1) {
mc->mc_txn->mt_dbs[mc->mc_dbi] = mx->mx_dbs[2];
mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty = mx->mx_dbxs[2].md_dirty;
}
}
int
mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
{
MDB_cursor *cursor;
size_t size = sizeof(MDB_cursor);
if (txn == NULL || ret == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
size += sizeof(MDB_xcursor);
if ((cursor = calloc(1, size)) != NULL) {
cursor->mc_dbi = dbi;
cursor->mc_txn = txn;
if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
MDB_xcursor *mx = (MDB_xcursor *)(cursor + 1);
cursor->mc_xcursor = mx;
mdb_xcursor_init0(cursor);
}
} else {
return ENOMEM;
}
*ret = cursor;
return MDB_SUCCESS;
}
/* Return the count of duplicate data items for the current key */
int
mdb_cursor_count(MDB_cursor *mc, unsigned long *countp)
{
MDB_ppage *top;
MDB_node *leaf;
if (mc == NULL || countp == NULL)
return EINVAL;
if (!(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT))
return EINVAL;
top = CURSOR_TOP(mc);
leaf = NODEPTR(top->mp_page, top->mp_ki);
if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
*countp = 1;
} else {
if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
return EINVAL;
*countp = mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi].md_entries;
}
return MDB_SUCCESS;
}
void
mdb_cursor_close(MDB_cursor *cursor)
{
if (cursor != NULL) {
free(cursor);
}
}
static int
mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key)
{
indx_t ptr, i, numkeys;
int delta;
size_t len;
MDB_node *node;
char *base;
DKBUF;
node = NODEPTR(mp, indx);
ptr = mp->mp_ptrs[indx];
DPRINTF("update key %u (ofs %u) [%.*s] to [%s] on page %lu",
indx, ptr,
(int)node->mn_ksize, (char *)NODEKEY(node),
DKEY(key),
mp->mp_pgno);
delta = key->mv_size - node->mn_ksize;
if (delta) {
if (delta > 0 && SIZELEFT(mp) < delta) {
DPRINTF("OUCH! Not enough room, delta = %d", delta);
return ENOSPC;
}
numkeys = NUMKEYS(mp);
for (i = 0; i < numkeys; i++) {
if (mp->mp_ptrs[i] <= ptr)
mp->mp_ptrs[i] -= delta;
}
base = (char *)mp + mp->mp_upper;
len = ptr - mp->mp_upper + NODESIZE;
memmove(base - delta, base, len);
mp->mp_upper -= delta;
node = NODEPTR(mp, indx);
node->mn_ksize = key->mv_size;
}
memcpy(NODEKEY(node), key->mv_data, key->mv_size);
return MDB_SUCCESS;
}
/* Move a node from src to dst.
*/
static int
mdb_move_node(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *src, indx_t srcindx,
MDB_pageparent *dst, indx_t dstindx)
{
int rc;
MDB_node *srcnode;
MDB_val key, data;
DKBUF;
/* Mark src and dst as dirty. */
if ((rc = mdb_touch(txn, dbi, src)) ||
(rc = mdb_touch(txn, dbi, dst)))
return rc;;
if (IS_LEAF2(src->mp_page)) {
srcnode = NODEPTR(src->mp_page, 0); /* fake */
key.mv_size = txn->mt_dbs[dbi].md_pad;
key.mv_data = LEAF2KEY(src->mp_page, srcindx, key.mv_size);
data.mv_size = 0;
data.mv_data = NULL;
} else {
srcnode = NODEPTR(src->mp_page, srcindx);
key.mv_size = NODEKSZ(srcnode);
key.mv_data = NODEKEY(srcnode);
data.mv_size = NODEDSZ(srcnode);
data.mv_data = NODEDATA(srcnode);
}
DPRINTF("moving %s node %u [%s] on page %lu to node %u on page %lu",
IS_LEAF(src->mp_page) ? "leaf" : "branch",
srcindx,
DKEY(&key),
src->mp_page->mp_pgno,
dstindx, dst->mp_page->mp_pgno);
/* Add the node to the destination page.
*/
rc = mdb_add_node(txn, dbi, dst->mp_page, dstindx, &key, &data, NODEPGNO(srcnode),
srcnode->mn_flags);
if (rc != MDB_SUCCESS)
return rc;
/* Delete the node from the source page.
*/
mdb_del_node(src->mp_page, srcindx, key.mv_size);
/* The key value just changed due to del_node, find it again.
*/
if (!IS_LEAF2(src->mp_page)) {
srcnode = NODEPTR(src->mp_page, srcindx);
key.mv_data = NODEKEY(srcnode);
}
/* Update the parent separators.
*/
if (srcindx == 0) {
if (src->mp_pi != 0) {
DPRINTF("update separator for source page %lu to [%s]",
src->mp_page->mp_pgno, DKEY(&key));
if ((rc = mdb_update_key(src->mp_parent, src->mp_pi,
&key)) != MDB_SUCCESS)
return rc;
}
if (IS_BRANCH(src->mp_page)) {
MDB_val nullkey;
nullkey.mv_size = 0;
assert(mdb_update_key(src->mp_page, 0, &nullkey) == MDB_SUCCESS);
}
}
if (dstindx == 0) {
if (dst->mp_pi != 0) {
DPRINTF("update separator for destination page %lu to [%s]",
dst->mp_page->mp_pgno, DKEY(&key));
if ((rc = mdb_update_key(dst->mp_parent, dst->mp_pi,
&key)) != MDB_SUCCESS)
return rc;
}
if (IS_BRANCH(dst->mp_page)) {
MDB_val nullkey;
nullkey.mv_size = 0;
assert(mdb_update_key(dst->mp_page, 0, &nullkey) == MDB_SUCCESS);
}
}
return MDB_SUCCESS;
}
static int
mdb_merge(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *src, MDB_pageparent *dst)
{
int rc;
indx_t i;
MDB_node *srcnode;
MDB_val key, data;
MDB_pageparent mpp;
MDB_dhead *dh;
DPRINTF("merging page %lu and %lu", src->mp_page->mp_pgno, dst->mp_page->mp_pgno);
assert(txn != NULL);
assert(src->mp_parent); /* can't merge root page */
assert(dst->mp_parent);
/* Mark src and dst as dirty. */
if ((rc = mdb_touch(txn, dbi, src)) ||
(rc = mdb_touch(txn, dbi, dst)))
return rc;
/* Move all nodes from src to dst.
*/
if (IS_LEAF2(src->mp_page)) {
key.mv_size = txn->mt_dbs[dbi].md_pad;
key.mv_data = METADATA(src->mp_page);
for (i = 0; i < NUMKEYS(src->mp_page); i++) {
rc = mdb_add_node(txn, dbi, dst->mp_page, NUMKEYS(dst->mp_page), &key,
NULL, 0, 0);
if (rc != MDB_SUCCESS)
return rc;
key.mv_data = (char *)key.mv_data + key.mv_size;
}
} else {
for (i = 0; i < NUMKEYS(src->mp_page); i++) {
srcnode = NODEPTR(src->mp_page, i);
key.mv_size = srcnode->mn_ksize;
key.mv_data = NODEKEY(srcnode);
data.mv_size = NODEDSZ(srcnode);
data.mv_data = NODEDATA(srcnode);
rc = mdb_add_node(txn, dbi, dst->mp_page, NUMKEYS(dst->mp_page), &key,
&data, NODEPGNO(srcnode), srcnode->mn_flags);
if (rc != MDB_SUCCESS)
return rc;
}
}
DPRINTF("dst page %lu now has %u keys (%.1f%% filled)",
dst->mp_page->mp_pgno, NUMKEYS(dst->mp_page), (float)PAGEFILL(txn->mt_env, dst->mp_page) / 10);
/* Unlink the src page from parent.
*/
mdb_del_node(src->mp_parent, src->mp_pi, 0);
if (src->mp_pi == 0) {
key.mv_size = 0;
if ((rc = mdb_update_key(src->mp_parent, 0, &key)) != MDB_SUCCESS)
return rc;
}
if (IS_LEAF(src->mp_page))
txn->mt_dbs[dbi].md_leaf_pages--;
else
txn->mt_dbs[dbi].md_branch_pages--;
mpp.mp_page = src->mp_parent;
dh = (MDB_dhead *)src->mp_parent;
dh--;
mpp.mp_parent = dh->md_parent;
mpp.mp_pi = dh->md_pi;
return mdb_rebalance(txn, dbi, &mpp);
}
#define FILL_THRESHOLD 250
static int
mdb_rebalance(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *mpp)
{
MDB_node *node;
MDB_page *root;
MDB_pageparent npp;
indx_t si = 0, di = 0;
int rc;
assert(txn != NULL);
assert(mpp != NULL);
DPRINTF("rebalancing %s page %lu (has %u keys, %.1f%% full)",
IS_LEAF(mpp->mp_page) ? "leaf" : "branch",
mpp->mp_page->mp_pgno, NUMKEYS(mpp->mp_page), (float)PAGEFILL(txn->mt_env, mpp->mp_page) / 10);
if (PAGEFILL(txn->mt_env, mpp->mp_page) >= FILL_THRESHOLD) {
DPRINTF("no need to rebalance page %lu, above fill threshold",
mpp->mp_page->mp_pgno);
return MDB_SUCCESS;
}
if (mpp->mp_parent == NULL) {
if (NUMKEYS(mpp->mp_page) == 0) {
DPUTS("tree is completely empty");
txn->mt_dbs[dbi].md_root = P_INVALID;
txn->mt_dbs[dbi].md_depth = 0;
txn->mt_dbs[dbi].md_leaf_pages = 0;
} else if (IS_BRANCH(mpp->mp_page) && NUMKEYS(mpp->mp_page) == 1) {
DPUTS("collapsing root page!");
txn->mt_dbs[dbi].md_root = NODEPGNO(NODEPTR(mpp->mp_page, 0));
if ((rc = mdb_get_page(txn, txn->mt_dbs[dbi].md_root, &root)))
return rc;
txn->mt_dbs[dbi].md_depth--;
txn->mt_dbs[dbi].md_branch_pages--;
} else
DPUTS("root page doesn't need rebalancing");
return MDB_SUCCESS;
}
/* The parent (branch page) must have at least 2 pointers,
* otherwise the tree is invalid.
*/
assert(NUMKEYS(mpp->mp_parent) > 1);
/* Leaf page fill factor is below the threshold.
* Try to move keys from left or right neighbor, or
* merge with a neighbor page.
*/
/* Find neighbors.
*/
if (mpp->mp_pi == 0) {
/* We're the leftmost leaf in our parent.
*/
DPUTS("reading right neighbor");
node = NODEPTR(mpp->mp_parent, mpp->mp_pi + 1);
if ((rc = mdb_get_page(txn, NODEPGNO(node), &npp.mp_page)))
return rc;
npp.mp_pi = mpp->mp_pi + 1;
si = 0;
di = NUMKEYS(mpp->mp_page);
} else {
/* There is at least one neighbor to the left.
*/
DPUTS("reading left neighbor");
node = NODEPTR(mpp->mp_parent, mpp->mp_pi - 1);
if ((rc = mdb_get_page(txn, NODEPGNO(node), &npp.mp_page)))
return rc;
npp.mp_pi = mpp->mp_pi - 1;
si = NUMKEYS(npp.mp_page) - 1;
di = 0;
}
npp.mp_parent = mpp->mp_parent;
DPRINTF("found neighbor page %lu (%u keys, %.1f%% full)",
npp.mp_page->mp_pgno, NUMKEYS(npp.mp_page), (float)PAGEFILL(txn->mt_env, npp.mp_page) / 10);
/* If the neighbor page is above threshold and has at least two
* keys, move one key from it.
*
* Otherwise we should try to merge them.
*/
if (PAGEFILL(txn->mt_env, npp.mp_page) >= FILL_THRESHOLD && NUMKEYS(npp.mp_page) >= 2)
return mdb_move_node(txn, dbi, &npp, si, mpp, di);
else { /* FIXME: if (has_enough_room()) */
if (mpp->mp_pi == 0)
return mdb_merge(txn, dbi, &npp, mpp);
else
return mdb_merge(txn, dbi, mpp, &npp);
}
}
static int
mdb_del0(MDB_txn *txn, MDB_dbi dbi, unsigned int ki, MDB_pageparent *mpp, MDB_node *leaf)
{
int rc;
/* add overflow pages to free list */
if (!IS_LEAF2(mpp->mp_page) && F_ISSET(leaf->mn_flags, F_BIGDATA)) {
int i, ovpages;
pgno_t pg;
memcpy(&pg, NODEDATA(leaf), sizeof(pg));
ovpages = OVPAGES(NODEDSZ(leaf), txn->mt_env->me_psize);
for (i=0; i<ovpages; i++) {
DPRINTF("freed ov page %lu", pg);
mdb_midl_insert(txn->mt_free_pgs, pg);
pg++;
}
}
mdb_del_node(mpp->mp_page, ki, txn->mt_dbs[dbi].md_pad);
txn->mt_dbs[dbi].md_entries--;
rc = mdb_rebalance(txn, dbi, mpp);
if (rc != MDB_SUCCESS)
txn->mt_flags |= MDB_TXN_ERROR;
return rc;
}
int
mdb_del(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data)
{
int rc, exact;
unsigned int ki;
MDB_node *leaf;
MDB_pageparent mpp;
DKBUF;
assert(key != NULL);
DPRINTF("====> delete db %u key [%s]", dbi, DKEY(key));
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
return EACCES;
}
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
return EINVAL;
}
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
if ((rc = mdb_search_page(txn, dbi, key, NULL, 1, &mpp)) != MDB_SUCCESS)
return rc;
leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, &ki);
if (leaf == NULL || !exact) {
return MDB_NOTFOUND;
}
if (!IS_LEAF2(mpp.mp_page) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
MDB_cursor mc;
MDB_xcursor mx;
MDB_pageparent mp2;
mc.mc_txn = txn;
mc.mc_dbi = dbi;
mc.mc_flags = 0;
mc.mc_xcursor = &mx;
mdb_xcursor_init0(&mc);
mdb_xcursor_init1(txn, dbi, &mx, mpp.mp_page, leaf);
if (data) {
rc = mdb_del(&mx.mx_txn, mx.mx_cursor.mc_dbi, data, NULL);
mdb_xcursor_fini(&mc);
/* If sub-DB still has entries, we're done */
if (mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi].md_root != P_INVALID) {
memcpy(NODEDATA(leaf), &mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi],
sizeof(MDB_db));
txn->mt_dbs[dbi].md_entries--;
return rc;
}
/* otherwise fall thru and delete the sub-DB */
} else {
/* add all the child DB's pages to the free list */
rc = mdb_search_page(&mx.mx_txn, mx.mx_cursor.mc_dbi,
NULL, &mx.mx_cursor, 0, &mp2);
if (rc == MDB_SUCCESS) {
MDB_ppage *top, *parent;
MDB_node *ni;
unsigned int i;
cursor_pop_page(&mx.mx_cursor);
if (mx.mx_cursor.mc_snum) {
top = CURSOR_TOP(&mx.mx_cursor);
while (mx.mx_cursor.mc_snum > 1) {
parent = CURSOR_PARENT(&mx.mx_cursor);
for (i=0; i<NUMKEYS(top->mp_page); i++) {
ni = NODEPTR(top->mp_page, i);
mdb_midl_insert(txn->mt_free_pgs, NODEPGNO(ni));
}
parent->mp_ki++;
if (parent->mp_ki >= NUMKEYS(parent->mp_page)) {
cursor_pop_page(&mx.mx_cursor);
top = parent;
} else {
ni = NODEPTR(parent->mp_page, parent->mp_ki);
rc = mdb_get_page(&mx.mx_txn, NODEPGNO(ni), &top->mp_page);
}
}
}
mdb_midl_insert(txn->mt_free_pgs, mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi].md_root);
}
}
}
return mdb_del0(txn, dbi, ki, &mpp, leaf);
}
/* Split page <*mpp>, and insert <key,(data|newpgno)> in either left or
* right sibling, at index <*newindxp> (as if unsplit). Updates *mpp and
* *newindxp with the actual values after split, ie if *mpp and *newindxp
* refer to a node in the new right sibling page.
*/
static int
mdb_split(MDB_txn *txn, MDB_dbi dbi, MDB_page **mpp, unsigned int *newindxp,
MDB_val *newkey, MDB_val *newdata, pgno_t newpgno)
{
uint8_t flags;
int rc = MDB_SUCCESS, ins_new = 0;
indx_t newindx;
pgno_t pgno = 0;
unsigned int i, j, split_indx, nkeys, pmax;
MDB_node *node;
MDB_val sepkey, rkey, rdata;
MDB_page *copy, *cptr;
MDB_dpage *mdp, *rdp, *pdp;
MDB_dhead *dh;
DKBUF;
assert(txn != NULL);
dh = ((MDB_dhead *)*mpp) - 1;
mdp = (MDB_dpage *)dh;
newindx = *newindxp;
DPRINTF("-----> splitting %s page %lu and adding [%s] at index %i",
IS_LEAF(&mdp->p) ? "leaf" : "branch", mdp->p.mp_pgno,
DKEY(newkey), *newindxp);
if (mdp->h.md_parent == NULL) {
if ((pdp = mdb_new_page(txn, dbi, P_BRANCH, 1)) == NULL)
return ENOMEM;
mdp->h.md_pi = 0;
mdp->h.md_parent = &pdp->p;
txn->mt_dbs[dbi].md_root = pdp->p.mp_pgno;
DPRINTF("root split! new root = %lu", pdp->p.mp_pgno);
txn->mt_dbs[dbi].md_depth++;
/* Add left (implicit) pointer. */
if ((rc = mdb_add_node(txn, dbi, &pdp->p, 0, NULL, NULL,
mdp->p.mp_pgno, 0)) != MDB_SUCCESS)
return rc;
} else {
DPRINTF("parent branch page is %lu", mdp->h.md_parent->mp_pgno);
}
/* Create a right sibling. */
if ((rdp = mdb_new_page(txn, dbi, mdp->p.mp_flags, 1)) == NULL)
return ENOMEM;
rdp->h.md_parent = mdp->h.md_parent;
rdp->h.md_pi = mdp->h.md_pi + 1;
DPRINTF("new right sibling: page %lu", rdp->p.mp_pgno);
nkeys = NUMKEYS(&mdp->p);
split_indx = nkeys / 2 + 1;
if (IS_LEAF2(&rdp->p)) {
char *split, *ins;
int x;
unsigned int lsize, rsize, ksize;
/* Move half of the keys to the right sibling */
copy = NULL;
x = *newindxp - split_indx;
ksize = txn->mt_dbs[dbi].md_pad;
split = LEAF2KEY(&mdp->p, split_indx, ksize);
rsize = (nkeys - split_indx) * ksize;
lsize = (nkeys - split_indx) * sizeof(indx_t);
mdp->p.mp_lower -= lsize;
rdp->p.mp_lower += lsize;
mdp->p.mp_upper += rsize - lsize;
rdp->p.mp_upper -= rsize - lsize;
sepkey.mv_size = ksize;
if (newindx == split_indx) {
sepkey.mv_data = newkey->mv_data;
} else {
sepkey.mv_data = split;
}
if (x<0) {
ins = LEAF2KEY(&mdp->p, *newindxp, ksize);
memcpy(&rdp->p.mp_ptrs, split, rsize);
sepkey.mv_data = &rdp->p.mp_ptrs;
memmove(ins+ksize, ins, (split_indx - *newindxp) * ksize);
memcpy(ins, newkey->mv_data, ksize);
mdp->p.mp_lower += sizeof(indx_t);
mdp->p.mp_upper -= ksize - sizeof(indx_t);
} else {
if (x)
memcpy(&rdp->p.mp_ptrs, split, x * ksize);
ins = LEAF2KEY(&rdp->p, x, ksize);
memcpy(ins, newkey->mv_data, ksize);
memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
rdp->p.mp_lower += sizeof(indx_t);
rdp->p.mp_upper -= ksize - sizeof(indx_t);
*newindxp = x;
*mpp = &rdp->p;
}
goto newsep;
}
/* For leaf pages, check the split point based on what
* fits where, since otherwise add_node can fail.
*/
if (IS_LEAF(&mdp->p)) {
unsigned int psize, nsize;
/* Maximum free space in an empty page */
pmax = txn->mt_env->me_psize - PAGEHDRSZ;
nsize = mdb_leaf_size(txn->mt_env, newkey, newdata);
if (newindx < split_indx) {
psize = nsize;
for (i=0; i<split_indx; i++) {
node = NODEPTR(&mdp->p, i);
psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
if (F_ISSET(node->mn_flags, F_BIGDATA))
psize += sizeof(pgno_t);
else
psize += NODEDSZ(node);
if (psize > pmax) {
split_indx = i;
break;
}
}
} else {
psize = nsize;
for (i=nkeys-1; i>=split_indx; i--) {
node = NODEPTR(&mdp->p, i);
psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
if (F_ISSET(node->mn_flags, F_BIGDATA))
psize += sizeof(pgno_t);
else
psize += NODEDSZ(node);
if (psize > pmax) {
split_indx = i+1;
break;
}
}
}
}
/* First find the separating key between the split pages.
*/
memset(&sepkey, 0, sizeof(sepkey));
if (newindx == split_indx) {
sepkey.mv_size = newkey->mv_size;
sepkey.mv_data = newkey->mv_data;
} else {
node = NODEPTR(&mdp->p, split_indx);
sepkey.mv_size = node->mn_ksize;
sepkey.mv_data = NODEKEY(node);
}
newsep:
DPRINTF("separator is [%s]", DKEY(&sepkey));
/* Copy separator key to the parent.
*/
if (SIZELEFT(rdp->h.md_parent) < mdb_branch_size(txn->mt_env, &sepkey)) {
rc = mdb_split(txn, dbi, &rdp->h.md_parent, &rdp->h.md_pi,
&sepkey, NULL, rdp->p.mp_pgno);
/* Right page might now have changed parent.
* Check if left page also changed parent.
*/
if (rdp->h.md_parent != mdp->h.md_parent &&
mdp->h.md_pi >= NUMKEYS(mdp->h.md_parent)) {
mdp->h.md_parent = rdp->h.md_parent;
mdp->h.md_pi = rdp->h.md_pi - 1;
}
} else {
rc = mdb_add_node(txn, dbi, rdp->h.md_parent, rdp->h.md_pi,
&sepkey, NULL, rdp->p.mp_pgno, 0);
}
if (IS_LEAF2(&rdp->p)) {
return rc;
}
if (rc != MDB_SUCCESS) {
return rc;
}
/* Move half of the keys to the right sibling. */
if ((copy = malloc(txn->mt_env->me_psize)) == NULL)
return ENOMEM;
copy->mp_pgno = mdp->p.mp_pgno;
copy->mp_flags = mdp->p.mp_flags;
copy->mp_lower = PAGEHDRSZ;
copy->mp_upper = txn->mt_env->me_psize;
cptr = copy;
for (i = j = 0; i <= nkeys; j++) {
if (i == split_indx) {
/* Insert in right sibling. */
/* Reset insert index for right sibling. */
j = (i == newindx && ins_new);
cptr = &rdp->p;
}
if (i == newindx && !ins_new) {
/* Insert the original entry that caused the split. */
rkey.mv_data = newkey->mv_data;
rkey.mv_size = newkey->mv_size;
if (IS_LEAF(&mdp->p)) {
rdata.mv_data = newdata->mv_data;
rdata.mv_size = newdata->mv_size;
} else
pgno = newpgno;
flags = 0;
ins_new = 1;
/* Update page and index for the new key. */
*newindxp = j;
if (cptr == &rdp->p)
*mpp = cptr;
} else if (i == nkeys) {
break;
} else {
node = NODEPTR(&mdp->p, i);
rkey.mv_data = NODEKEY(node);
rkey.mv_size = node->mn_ksize;
if (IS_LEAF(&mdp->p)) {
rdata.mv_data = NODEDATA(node);
rdata.mv_size = node->mn_dsize;
} else
pgno = NODEPGNO(node);
flags = node->mn_flags;
i++;
}
if (!IS_LEAF(&mdp->p) && j == 0) {
/* First branch index doesn't need key data. */
rkey.mv_size = 0;
}
rc = mdb_add_node(txn, dbi, cptr, j, &rkey, &rdata, pgno, flags);
}
nkeys = NUMKEYS(copy);
for (i=0; i<nkeys; i++)
mdp->p.mp_ptrs[i] = copy->mp_ptrs[i];
mdp->p.mp_lower = copy->mp_lower;
mdp->p.mp_upper = copy->mp_upper;
memcpy(NODEPTR(&mdp->p, nkeys-1), NODEPTR(copy, nkeys-1),
txn->mt_env->me_psize - copy->mp_upper);
free(copy);
return rc;
}
static int
mdb_put0(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data, unsigned int flags)
{
int rc = MDB_SUCCESS, exact;
unsigned int ki;
MDB_node *leaf;
MDB_pageparent mpp;
MDB_val xdata, *rdata, dkey;
MDB_db dummy;
char dbuf[PAGESIZE];
int do_sub = 0;
size_t nsize;
DKBUF;
DPRINTF("==> put db %u key [%s], size %zu, data size %zu",
dbi, DKEY(key), key->mv_size, data->mv_size);
dkey.mv_size = 0;
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
rc = mdb_search_page(txn, dbi, key, NULL, 1, &mpp);
if (rc == MDB_SUCCESS) {
leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, &ki);
if (leaf && exact) {
if (flags == MDB_NOOVERWRITE) {
DPRINTF("duplicate key [%s]", DKEY(key));
return MDB_KEYEXIST;
}
/* there's only a key anyway, so this is a no-op */
if (IS_LEAF2(mpp.mp_page))
return MDB_SUCCESS;
if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
/* Was a single item before, must convert now */
if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
dkey.mv_size = NODEDSZ(leaf);
dkey.mv_data = dbuf;
memcpy(dbuf, NODEDATA(leaf), dkey.mv_size);
/* data matches, ignore it */
if (!mdb_dcmp(txn, dbi, data, &dkey))
return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS;
memset(&dummy, 0, sizeof(dummy));
if (txn->mt_dbs[dbi].md_flags & MDB_DUPFIXED) {
dummy.md_pad = data->mv_size;
dummy.md_flags = MDB_DUPFIXED;
if (txn->mt_dbs[dbi].md_flags & MDB_INTEGERDUP)
dummy.md_flags |= MDB_INTEGERKEY;
}
dummy.md_root = P_INVALID;
if (dkey.mv_size == sizeof(MDB_db)) {
memcpy(NODEDATA(leaf), &dummy, sizeof(dummy));
goto put_sub;
}
mdb_del_node(mpp.mp_page, ki, 0);
do_sub = 1;
rdata = &xdata;
xdata.mv_size = sizeof(MDB_db);
xdata.mv_data = &dummy;
goto new_sub;
}
goto put_sub;
}
/* same size, just replace it */
if (!F_ISSET(leaf->mn_flags, F_BIGDATA) &&
NODEDSZ(leaf) == data->mv_size) {
memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
goto done;
}
mdb_del_node(mpp.mp_page, ki, 0);
}
if (leaf == NULL) { /* append if not found */
ki = NUMKEYS(mpp.mp_page);
DPRINTF("appending key at index %i", ki);
}
} else if (rc == MDB_NOTFOUND) {
MDB_dpage *dp;
/* new file, just write a root leaf page */
DPUTS("allocating new root leaf page");
if ((dp = mdb_new_page(txn, dbi, P_LEAF, 1)) == NULL) {
return ENOMEM;
}
mpp.mp_page = &dp->p;
txn->mt_dbs[dbi].md_root = mpp.mp_page->mp_pgno;
txn->mt_dbs[dbi].md_depth++;
txn->mt_dbxs[dbi].md_dirty = 1;
if ((txn->mt_dbs[dbi].md_flags & (MDB_DUPSORT|MDB_DUPFIXED)) == MDB_DUPFIXED)
mpp.mp_page->mp_flags |= P_LEAF2;
ki = 0;
}
else
goto done;
assert(IS_LEAF(mpp.mp_page));
DPRINTF("there are %u keys, should insert new key at index %i",
NUMKEYS(mpp.mp_page), ki);
rdata = data;
new_sub:
nsize = IS_LEAF2(mpp.mp_page) ? key->mv_size : mdb_leaf_size(txn->mt_env, key, rdata);
if (SIZELEFT(mpp.mp_page) < nsize) {
rc = mdb_split(txn, dbi, &mpp.mp_page, &ki, key, rdata, P_INVALID);
} else {
/* There is room already in this leaf page. */
rc = mdb_add_node(txn, dbi, mpp.mp_page, ki, key, rdata, 0, 0);
}
if (rc != MDB_SUCCESS)
txn->mt_flags |= MDB_TXN_ERROR;
else {
/* Remember if we just added a subdatabase */
if (flags & F_SUBDATA) {
leaf = NODEPTR(mpp.mp_page, ki);
leaf->mn_flags |= F_SUBDATA;
}
/* Now store the actual data in the child DB. Note that we're
* storing the user data in the keys field, so there are strict
* size limits on dupdata. The actual data fields of the child
* DB are all zero size.
*/
if (do_sub) {
MDB_cursor mc;
MDB_xcursor mx;
leaf = NODEPTR(mpp.mp_page, ki);
put_sub:
mc.mc_txn = txn;
mc.mc_dbi = dbi;
mc.mc_flags = 0;
mc.mc_xcursor = &mx;
mdb_xcursor_init0(&mc);
mdb_xcursor_init1(txn, dbi, &mx, mpp.mp_page, leaf);
xdata.mv_size = 0;
xdata.mv_data = "";
if (flags == MDB_NODUPDATA)
flags = MDB_NOOVERWRITE;
/* converted, write the original data first */
if (dkey.mv_size) {
rc = mdb_put0(&mx.mx_txn, mx.mx_cursor.mc_dbi, &dkey, &xdata, flags);
if (rc) return rc;
leaf->mn_flags |= F_DUPDATA;
}
rc = mdb_put0(&mx.mx_txn, mx.mx_cursor.mc_dbi, data, &xdata, flags);
mdb_xcursor_fini(&mc);
memcpy(NODEDATA(leaf), &mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi],
sizeof(MDB_db));
}
txn->mt_dbs[dbi].md_entries++;
}
done:
return rc;
}
int
mdb_put(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data, unsigned int flags)
{
MDB_cursor mc;
MDB_xcursor mx;
int rc;
assert(key != NULL);
assert(data != NULL);
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
return EACCES;
}
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
return EINVAL;
}
if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA)) != flags)
return EINVAL;
mc.mc_txn = txn;
mc.mc_dbi = dbi;
mc.mc_snum = 0;
mc.mc_flags = 0;
if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
mc.mc_xcursor = &mx;
mdb_xcursor_init0(&mc);
} else {
mc.mc_xcursor = NULL;
}
rc = mdb_cursor_put(&mc, key, data, flags);
if (mc.mc_xcursor) {
MDB_ppage *top;
MDB_node *leaf;
mdb_xcursor_fini(&mc);
top = CURSOR_TOP(&mc);
leaf = NODEPTR(top->mp_page, top->mp_ki);
memcpy(NODEDATA(leaf), &mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi],
sizeof(MDB_db));
}
return rc;
}
int
mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
{
#define CHANGEABLE (MDB_NOSYNC)
if ((flag & CHANGEABLE) != flag)
return EINVAL;
if (onoff)
env->me_flags |= flag;
else
env->me_flags &= ~flag;
return MDB_SUCCESS;
}
int
mdb_env_get_flags(MDB_env *env, unsigned int *arg)
{
if (!env || !arg)
return EINVAL;
*arg = env->me_flags;
return MDB_SUCCESS;
}
int
mdb_env_get_path(MDB_env *env, const char **arg)
{
if (!env || !arg)
return EINVAL;
*arg = env->me_path;
return MDB_SUCCESS;
}
static int
mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
{
arg->ms_psize = env->me_psize;
arg->ms_depth = db->md_depth;
arg->ms_branch_pages = db->md_branch_pages;
arg->ms_leaf_pages = db->md_leaf_pages;
arg->ms_overflow_pages = db->md_overflow_pages;
arg->ms_entries = db->md_entries;
return MDB_SUCCESS;
}
int
mdb_env_stat(MDB_env *env, MDB_stat *arg)
{
int toggle;
if (env == NULL || arg == NULL)
return EINVAL;
mdb_env_read_meta(env, &toggle);
return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
}
int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
{
MDB_val key, data;
MDB_dbi i;
int rc, dirty = 0;
size_t len;
/* main DB? */
if (!name) {
*dbi = MAIN_DBI;
if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY))
txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY));
return MDB_SUCCESS;
}
/* Is the DB already open? */
len = strlen(name);
for (i=2; i<txn->mt_numdbs; i++) {
if (len == txn->mt_dbxs[i].md_name.mv_size &&
!strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
*dbi = i;
return MDB_SUCCESS;
}
}
if (txn->mt_numdbs >= txn->mt_env->me_maxdbs - 1)
return ENFILE;
/* Find the DB info */
key.mv_size = len;
key.mv_data = (void *)name;
rc = mdb_get(txn, MAIN_DBI, &key, &data);
/* Create if requested */
if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
MDB_db dummy;
data.mv_size = sizeof(MDB_db);
data.mv_data = &dummy;
memset(&dummy, 0, sizeof(dummy));
dummy.md_root = P_INVALID;
dummy.md_flags = flags & 0xffff;
rc = mdb_put0(txn, MAIN_DBI, &key, &data, F_SUBDATA);
dirty = 1;
}
/* OK, got info, add to table */
if (rc == MDB_SUCCESS) {
txn->mt_dbxs[txn->mt_numdbs].md_name.mv_data = strdup(name);
txn->mt_dbxs[txn->mt_numdbs].md_name.mv_size = len;
txn->mt_dbxs[txn->mt_numdbs].md_cmp = NULL;
txn->mt_dbxs[txn->mt_numdbs].md_dcmp = NULL;
txn->mt_dbxs[txn->mt_numdbs].md_rel = NULL;
txn->mt_dbxs[txn->mt_numdbs].md_parent = MAIN_DBI;
txn->mt_dbxs[txn->mt_numdbs].md_dirty = dirty;
memcpy(&txn->mt_dbs[txn->mt_numdbs], data.mv_data, sizeof(MDB_db));
*dbi = txn->mt_numdbs;
txn->mt_env->me_dbs[0][txn->mt_numdbs] = txn->mt_dbs[txn->mt_numdbs];
txn->mt_env->me_dbs[1][txn->mt_numdbs] = txn->mt_dbs[txn->mt_numdbs];
txn->mt_numdbs++;
}
return rc;
}
int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
{
if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
return EINVAL;
return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
}
void mdb_close(MDB_txn *txn, MDB_dbi dbi)
{
char *ptr;
if (dbi <= MAIN_DBI || dbi >= txn->mt_numdbs)
return;
ptr = txn->mt_dbxs[dbi].md_name.mv_data;
txn->mt_dbxs[dbi].md_name.mv_data = NULL;
txn->mt_dbxs[dbi].md_name.mv_size = 0;
free(ptr);
}
int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
{
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
txn->mt_dbxs[dbi].md_cmp = cmp;
return MDB_SUCCESS;
}
int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
{
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
txn->mt_dbxs[dbi].md_dcmp = cmp;
return MDB_SUCCESS;
}
int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
{
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
txn->mt_dbxs[dbi].md_rel = rel;
return MDB_SUCCESS;
}
/** @} */