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.
81 Commits
14 Branches
24 Tags
3.2 MiB
 
 
 
Tag: Branch: Tree: 76d7ca8ce0
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from '76d7ca8ce0'
${ noResults }
lmdb/libraries/libmdb/mdb.c

3245 lines
80 KiB
Raw Blame History

/* mdb.c - memory-mapped database library */
/*
* 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/queue.h>
#include <sys/param.h>
#include <sys/uio.h>
#include <sys/mman.h>
#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#include <fcntl.h>
#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>
#include <pthread.h>
#include "mdb.h"
#define ULONG unsigned long
typedef ULONG pgno_t;
#include "midl.h"
#ifndef DEBUG
#define DEBUG 1
#endif
#if DEBUG && defined(__GNUC__)
# define DPRINTF(fmt, ...) \
fprintf(stderr, "%s:%d: " fmt "\n", __func__, __LINE__, ##__VA_ARGS__)
#else
# define DPRINTF(...) ((void) 0)
#endif
#define PAGESIZE 4096
#define MDB_MINKEYS 4
#define MDB_MAGIC 0xBEEFC0DE
#define MDB_VERSION 1
#define MAXKEYSIZE 511
#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 */
#define RXBODY \
ULONG mr_txnid; \
pid_t mr_pid; \
pthread_t mr_tid
typedef struct MDB_rxbody {
RXBODY;
} MDB_rxbody;
#ifndef CACHELINE
# ifdef __APPLE__
# define CACHELINE 128 /* 64 is too small to contain a mutex */
# else
# define CACHELINE 64 /* most CPUs. Itanium uses 128 */
# endif
#endif
typedef struct MDB_reader {
RXBODY;
/* cache line alignment */
char pad[CACHELINE-sizeof(MDB_rxbody)];
} MDB_reader;
#define TXBODY \
uint32_t mt_magic; \
uint32_t mt_version; \
pthread_mutex_t mt_mutex; \
ULONG mt_txnid; \
uint32_t mt_numreaders
typedef struct MDB_txbody {
TXBODY;
} MDB_txbody;
typedef struct MDB_txninfo {
TXBODY;
char pad[CACHELINE-sizeof(MDB_txbody)];
pthread_mutex_t mt_wmutex;
char pad2[CACHELINE-sizeof(pthread_mutex_t)];
MDB_reader mt_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_pad;
} 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 */
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_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 + size + psize - 1) / psize;
typedef struct MDB_db {
uint32_t md_pad;
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 */
STAILQ_ENTRY(MDB_dpage) md_next; /* queue of dirty pages */
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;
STAILQ_HEAD(dirty_queue, MDB_dpage); /* FIXME: use a sorted data structure */
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_page *parent, unsigned int parent_idx, int num);
static int mdb_touch(MDB_txn *txn, MDB_pageparent *mp);
typedef struct MDB_ppage { /* ordered list of pages */
SLIST_ENTRY(MDB_ppage) mp_entry;
MDB_page *mp_page;
unsigned int mp_ki; /* cursor index on page */
} MDB_ppage;
SLIST_HEAD(page_stack, MDB_ppage);
/* FIXME: tree depth is mostly bounded, we should just
* use a fixed array and avoid malloc/pointer chasing
*/
#define CURSOR_EMPTY(c) SLIST_EMPTY(&(c)->mc_stack)
#define CURSOR_TOP(c) SLIST_FIRST(&(c)->mc_stack)
#define CURSOR_POP(c) SLIST_REMOVE_HEAD(&(c)->mc_stack, mp_entry)
#define CURSOR_PUSH(c,p) SLIST_INSERT_HEAD(&(c)->mc_stack, p, mp_entry)
struct MDB_xcursor;
struct MDB_cursor {
MDB_txn *mc_txn;
struct page_stack mc_stack; /* stack of parent pages */
MDB_dbi mc_dbi;
short mc_initialized; /* 1 if initialized */
short mc_eof; /* 1 if end is reached */
struct MDB_xcursor *mc_xcursor;
};
#define METAHASHLEN offsetof(MDB_meta, mm_hash)
#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 */
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;
ULONG mt_oldest;
MDB_env *mt_env;
pgno_t *mt_free_pgs; /* this is an IDL */
union {
struct dirty_queue *dirty_queue; /* 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 */
#define MDB_TXN_METOGGLE 0x04 /* used meta page 1 */
unsigned int mt_flags;
};
/* 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 {
int me_fd;
int me_lfd;
uint32_t me_flags;
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_meta *me_meta;
MDB_txn *me_txn; /* current write transaction */
size_t me_mapsize;
off_t me_size; /* current file size */
unsigned int me_psize;
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 */
pgno_t me_free_pgs[MDB_IDL_UM_SIZE];
};
#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 MDB_COMMIT_PAGES 64 /* max number of pages to write in one commit */
#define MDB_MAXCACHE_DEF 1024 /* max number of pages to keep in cache */
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 MDB_page *mdb_get_page(MDB_txn *txn, pgno_t pgno);
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);
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_set_key(MDB_node *node, MDB_val *key);
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_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
static void mdb_xcursor_init1(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx, MDB_node *node);
static void mdb_xcursor_fini(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
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);
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;
}
int
mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
{
return txn->mt_dbxs[dbi].md_cmp(a, b);
}
static int
_mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *key1, const MDB_val *key2)
{
if (txn->mt_dbs[dbi].md_flags & (MDB_REVERSEKEY
#if __BYTE_ORDER == __LITTLE_ENDIAN
|MDB_INTEGERKEY
#endif
))
return memnrcmp(key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
else
return memncmp((char *)key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
}
/* Allocate new page(s) for writing */
static MDB_dpage *
mdb_alloc_page(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num)
{
MDB_dpage *dp;
pgno_t pgno = P_INVALID;
ULONG oldest;
if (txn->mt_txnid > 2) {
oldest = txn->mt_txnid - 2;
if (!txn->mt_env->me_pghead && txn->mt_dbs[FREE_DBI].md_root != P_INVALID) {
/* See if there's anything in the free DB */
MDB_pageparent mpp;
MDB_node *leaf;
ULONG *kptr;
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
mdb_search_page(txn, FREE_DBI, NULL, NULL, 0, &mpp);
leaf = NODEPTR(mpp.mp_page, 0);
kptr = (ULONG *)NODEKEY(leaf);
/* It's potentially usable, unless there are still
* older readers outstanding. Grab it.
*/
if (oldest > *kptr) {
MDB_oldpages *mop;
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 */
mpp.mp_parent = NULL;
mpp.mp_pi = 0;
mdb_search_page(txn, FREE_DBI, NULL, NULL, 1, &mpp);
leaf = NODEPTR(mpp.mp_page, 0);
mdb_del0(txn, FREE_DBI, 0, &mpp, leaf);
}
}
if (txn->mt_env->me_pghead) {
unsigned int i;
for (i=0; i<txn->mt_env->me_txns->mt_numreaders; i++) {
ULONG mr = txn->mt_env->me_txns->mt_readers[i].mr_txnid;
if (!mr) continue;
if (mr < oldest)
oldest = txn->mt_env->me_txns->mt_readers[i].mr_txnid;
}
if (oldest > txn->mt_env->me_pghead->mo_txnid) {
MDB_oldpages *mop = txn->mt_env->me_pghead;
txn->mt_oldest = oldest;
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 ((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;
STAILQ_INSERT_TAIL(txn->mt_u.dirty_queue, dp, h.md_next);
if (pgno == P_INVALID) {
dp->p.mp_pgno = txn->mt_next_pgno;
txn->mt_next_pgno += num;
} else {
dp->p.mp_pgno = pgno;
}
return dp;
}
/* Touch a page: make it dirty and re-insert into tree with updated pgno.
*/
static int
mdb_touch(MDB_txn *txn, 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, pp->mp_parent, pp->mp_pi, 1)) == NULL)
return ENOMEM;
DPRINTF("touched page %lu -> %lu", 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 rc = 0;
if (!F_ISSET(env->me_flags, MDB_NOSYNC)) {
if (fsync(env->me_fd))
rc = errno;
}
return rc;
}
int
mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
{
MDB_txn *txn;
int rc, toggle;
if ((txn = calloc(1, sizeof(MDB_txn))) == NULL) {
DPRINTF("calloc: %s", strerror(errno));
return ENOMEM;
}
if (rdonly) {
txn->mt_flags |= MDB_TXN_RDONLY;
} else {
txn->mt_u.dirty_queue = calloc(1, sizeof(*txn->mt_u.dirty_queue));
if (txn->mt_u.dirty_queue == NULL) {
free(txn);
return ENOMEM;
}
STAILQ_INIT(txn->mt_u.dirty_queue);
pthread_mutex_lock(&env->me_txns->mt_wmutex);
env->me_txns->mt_txnid++;
txn->mt_free_pgs = env->me_free_pgs;
txn->mt_free_pgs[0] = 0;
}
txn->mt_txnid = env->me_txns->mt_txnid;
if (rdonly) {
MDB_reader *r = pthread_getspecific(env->me_txkey);
if (!r) {
unsigned int i;
pthread_mutex_lock(&env->me_txns->mt_mutex);
for (i=0; i<env->me_txns->mt_numreaders; i++)
if (env->me_txns->mt_readers[i].mr_pid == 0)
break;
if (i == env->me_maxreaders) {
pthread_mutex_unlock(&env->me_txns->mti_mutex);
return ENOSPC;
}
env->me_txns->mt_readers[i].mr_pid = getpid();
env->me_txns->mt_readers[i].mr_tid = pthread_self();
r = &env->me_txns->mt_readers[i];
pthread_setspecific(env->me_txkey, r);
if (i >= env->me_txns->mt_numreaders)
env->me_txns->mt_numreaders = i+1;
pthread_mutex_unlock(&env->me_txns->mt_mutex);
}
r->mr_txnid = txn->mt_txnid;
txn->mt_u.reader = r;
} else {
env->me_txn = txn;
}
txn->mt_env = env;
if ((rc = mdb_env_read_meta(env, &toggle)) != MDB_SUCCESS) {
mdb_txn_abort(txn);
return rc;
}
/* Copy the DB arrays */
txn->mt_numdbs = env->me_numdbs;
txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
txn->mt_dbs = malloc(env->me_maxdbs * sizeof(MDB_db));
memcpy(txn->mt_dbs, env->me_meta->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));
if (!rdonly) {
if (toggle)
txn->mt_flags |= MDB_TXN_METOGGLE;
txn->mt_next_pgno = env->me_meta->mm_last_pg+1;
}
DPRINTF("begin transaction %lu on mdbenv %p, root page %lu",
txn->mt_txnid, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
*ret = txn;
return MDB_SUCCESS;
}
void
mdb_txn_abort(MDB_txn *txn)
{
MDB_dpage *dp;
MDB_env *env;
if (txn == NULL)
return;
env = txn->mt_env;
DPRINTF("abort transaction %lu on mdbenv %p, root page %lu",
txn->mt_txnid, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
free(txn->mt_dbs);
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
txn->mt_u.reader->mr_txnid = 0;
} else {
MDB_oldpages *mop;
unsigned int i;
/* Discard all dirty pages. */
while (!STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
dp = STAILQ_FIRST(txn->mt_u.dirty_queue);
STAILQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
free(dp);
}
free(txn->mt_u.dirty_queue);
while ((mop = txn->mt_env->me_pghead)) {
txn->mt_env->me_pghead = mop->mo_next;
free(mop);
}
env->me_txn = NULL;
env->me_txns->mt_txnid--;
for (i=2; i<env->me_numdbs; i++)
env->me_dbxs[i].md_dirty = 0;
pthread_mutex_unlock(&env->me_txns->mt_wmutex);
}
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;
struct iovec iov[MDB_COMMIT_PAGES];
assert(txn != NULL);
assert(txn->mt_env != NULL);
env = txn->mt_env;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
DPRINTF("attempt to commit read-only transaction");
mdb_txn_abort(txn);
return EPERM;
}
if (txn != env->me_txn) {
DPRINTF("attempt to commit unknown transaction");
mdb_txn_abort(txn);
return EINVAL;
}
if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
DPRINTF("error flag is set, can't commit");
mdb_txn_abort(txn);
return EINVAL;
}
if (STAILQ_EMPTY(txn->mt_u.dirty_queue))
goto done;
DPRINTF("committing transaction %lu on mdbenv %p, root page %lu",
txn->mt_txnid, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
/* 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;
}
/* save to free list */
if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
MDB_val key, data;
MDB_pageparent mpp;
/* 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_size = MDB_IDL_SIZEOF(txn->mt_free_pgs);
data.mv_data = txn->mt_free_pgs;
mdb_put0(txn, FREE_DBI, &key, &data, 0);
}
/* 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;
do {
n = 0;
done = 1;
size = 0;
STAILQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
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 = errno;
if (rc > 0)
DPRINTF("short write, filesystem full?");
else
DPRINTF("writev: %s", strerror(errno));
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;
break;
}
}
if (n == 0)
break;
DPRINTF("committing %u dirty pages", n);
rc = writev(env->me_fd, iov, n);
if (rc != size) {
n = errno;
if (rc > 0)
DPRINTF("short write, filesystem full?");
else
DPRINTF("writev: %s", strerror(errno));
mdb_txn_abort(txn);
return n;
}
} while (!done);
/* Drop the dirty pages.
*/
while (!STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
dp = STAILQ_FIRST(txn->mt_u.dirty_queue);
STAILQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
free(dp);
}
if ((n = mdb_env_sync(env)) != 0 ||
(n = mdb_env_write_meta(txn)) != MDB_SUCCESS ||
(n = mdb_env_sync(env)) != 0) {
mdb_txn_abort(txn);
return n;
}
env->me_txn = NULL;
/* update the DB tables */
{
int toggle = !env->me_db_toggle;
for (i = 2; i < env->me_numdbs; i++) {
if (txn->mt_dbxs[i].md_dirty) {
env->me_dbs[toggle][i] = txn->mt_dbs[i];
txn->mt_dbxs[i].md_dirty = 0;
}
}
for (i = env->me_numdbs; i < txn->mt_numdbs; i++) {
txn->mt_dbxs[i].md_dirty = 0;
env->me_dbxs[i] = txn->mt_dbxs[i];
env->me_dbs[toggle][i] = txn->mt_dbs[i];
}
env->me_db_toggle = toggle;
env->me_numdbs = txn->mt_numdbs;
free(txn->mt_dbs);
}
pthread_mutex_unlock(&env->me_txns->mt_wmutex);
free(txn->mt_u.dirty_queue);
free(txn);
txn = NULL;
done:
mdb_txn_abort(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;
assert(env != NULL);
/* We don't know the page size yet, so use a minimum value.
*/
if ((rc = pread(env->me_fd, page, PAGESIZE, 0)) == 0) {
return ENOENT;
} else if (rc != PAGESIZE) {
if (rc > 0)
errno = EINVAL;
DPRINTF("read: %s", strerror(errno));
return errno;
}
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) {
DPRINTF("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;
DPRINTF("writing new meta page");
psize = sysconf(_SC_PAGE_SIZE);
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));
rc = write(env->me_fd, p, psize * 2);
free(p);
return (rc == (int)psize * 2) ? MDB_SUCCESS : errno;
}
static int
mdb_env_write_meta(MDB_txn *txn)
{
MDB_env *env;
MDB_meta meta;
off_t off;
int rc, len;
char *ptr;
assert(txn != NULL);
assert(txn->mt_env != NULL);
DPRINTF("writing meta page %d for root page %lu",
!F_ISSET(txn->mt_flags, MDB_TXN_METOGGLE), txn->mt_dbs[MAIN_DBI].md_root);
env = txn->mt_env;
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 (!F_ISSET(txn->mt_flags, MDB_TXN_METOGGLE))
off += env->me_psize;
off += PAGEHDRSZ;
lseek(env->me_fd, off, SEEK_SET);
rc = write(env->me_fd, ptr, len);
if (rc != len) {
DPRINTF("write failed, disk error?");
return errno;
}
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;
if (env->me_meta != env->me_metas[toggle])
env->me_meta = env->me_metas[toggle];
if (which)
*which = toggle;
DPRINTF("Using meta page %d", 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 = -1;
e->me_lfd = -1;
*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)
{
env->me_maxdbs = dbs;
return MDB_SUCCESS;
}
int
mdb_env_set_maxreaders(MDB_env *env, int readers)
{
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;
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;
DPRINTF("new mdbenv");
newenv = 1;
}
if (!env->me_mapsize) {
env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
}
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 errno;
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;
p = (MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(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, NULL)) != 0)
return i;
DPRINTF("opened database version %u, pagesize %u",
env->me_meta->mm_version, env->me_psize);
DPRINTF("depth: %u", env->me_meta->mm_dbs[MAIN_DBI].md_depth);
DPRINTF("entries: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_entries);
DPRINTF("branch pages: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_branch_pages);
DPRINTF("leaf pages: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_leaf_pages);
DPRINTF("overflow pages: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_overflow_pages);
DPRINTF("root: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_root);
return MDB_SUCCESS;
}
static void
mdb_env_reader_dest(void *ptr)
{
MDB_reader *reader = ptr;
reader->mr_txnid = 0;
reader->mr_pid = 0;
reader->mr_tid = 0;
}
/* downgrade the exclusive lock on the region back to shared */
static void
mdb_env_share_locks(MDB_env *env)
{
struct flock lock_info;
env->me_txns->mt_txnid = env->me_meta->mm_txnid;
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);
}
static int
mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
{
int rc;
off_t size, rsize;
struct flock lock_info;
*excl = 0;
if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
rc = errno;
return rc;
}
/* Try to get exclusive lock. If we succeed, then
* nobody is using the lock region and we should initialize it.
*/
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_SETLK, &lock_info);
if (rc) {
rc = errno;
goto fail;
}
}
size = lseek(env->me_lfd, 0, SEEK_END);
rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
if (size < rsize && *excl) {
if (ftruncate(env->me_lfd, rsize) != 0) {
rc = errno;
goto fail;
}
} else {
rsize = size;
size = rsize - sizeof(MDB_txninfo);
env->me_maxreaders = size/sizeof(MDB_reader) + 1;
}
env->me_txns = mmap(0, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
env->me_lfd, 0);
if (env->me_txns == MAP_FAILED) {
rc = errno;
goto fail;
}
if (*excl) {
pthread_mutexattr_t mattr;
pthread_mutexattr_init(&mattr);
pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
pthread_mutex_init(&env->me_txns->mt_mutex, &mattr);
pthread_mutex_init(&env->me_txns->mt_wmutex, &mattr);
env->me_txns->mt_version = MDB_VERSION;
env->me_txns->mt_magic = MDB_MAGIC;
env->me_txns->mt_txnid = 0;
env->me_txns->mt_numreaders = 0;
} else {
if (env->me_txns->mt_magic != MDB_MAGIC) {
DPRINTF("lock region has invalid magic");
rc = EINVAL;
goto fail;
}
if (env->me_txns->mt_version != MDB_VERSION) {
DPRINTF("lock region is version %u, expected version %u",
env->me_txns->mt_version, MDB_VERSION);
rc = MDB_VERSION_MISMATCH;
goto fail;
}
if (errno != EACCES && errno != EAGAIN) {
rc = errno;
goto fail;
}
}
return MDB_SUCCESS;
fail:
close(env->me_lfd);
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;
if (F_ISSET(flags, MDB_RDONLY))
oflags = O_RDONLY;
else
oflags = O_RDWR | O_CREAT;
if ((env->me_fd = open(dpath, oflags, mode)) == -1)
return errno;
if ((rc = mdb_env_open2(env, flags)) != MDB_SUCCESS) {
close(env->me_fd);
env->me_fd = -1;
} else {
env->me_path = strdup(path);
DPRINTF("opened dbenv %p", (void *) env);
pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
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:
free(lpath);
return rc;
}
void
mdb_env_close(MDB_env *env)
{
if (env == NULL)
return;
free(env->me_dbs[1]);
free(env->me_dbs[0]);
free(env->me_dbxs);
free(env->me_path);
pthread_key_delete(env->me_txkey);
if (env->me_map) {
munmap(env->me_map, env->me_mapsize);
}
close(env->me_fd);
if (env->me_txns) {
pid_t pid = getpid();
size_t size = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
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, size);
}
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;
MDB_val nodekey;
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;
node = NODEPTR(mp, i);
nodekey.mv_size = node->mn_ksize;
nodekey.mv_data = NODEKEY(node);
if (txn->mt_dbxs[dbi].md_cmp)
rc = txn->mt_dbxs[dbi].md_cmp(key, &nodekey);
else
rc = _mdb_cmp(txn, dbi, key, &nodekey);
if (IS_LEAF(mp))
DPRINTF("found leaf index %u [%.*s], rc = %i",
i, (int)nodekey.mv_size, (char *)nodekey.mv_data, rc);
else
DPRINTF("found branch index %u [%.*s -> %lu], rc = %i",
i, (int)node->mn_ksize, (char *)NODEKEY(node),
node->mn_pgno, 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;
return NODEPTR(mp, i);
}
static void
cursor_pop_page(MDB_cursor *cursor)
{
MDB_ppage *top;
top = CURSOR_TOP(cursor);
CURSOR_POP(cursor);
DPRINTF("popped page %lu off cursor %p", top->mp_page->mp_pgno, (void *) cursor);
free(top);
}
static MDB_ppage *
cursor_push_page(MDB_cursor *cursor, MDB_page *mp)
{
MDB_ppage *ppage;
DPRINTF("pushing page %lu on cursor %p", mp->mp_pgno, (void *) cursor);
if ((ppage = calloc(1, sizeof(MDB_ppage))) == NULL)
return NULL;
ppage->mp_page = mp;
CURSOR_PUSH(cursor, ppage);
return ppage;
}
static MDB_page *
mdb_get_page(MDB_txn *txn, pgno_t pgno)
{
MDB_page *p = NULL;
int found = 0;
if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && !STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
MDB_dpage *dp;
STAILQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
if (dp->p.mp_pgno == pgno) {
p = &dp->p;
found = 1;
break;
}
}
}
if (!found) {
if (pgno > txn->mt_env->me_meta->mm_last_pg)
return NULL;
p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
}
return p;
}
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;
int rc;
if (cursor && cursor_push_page(cursor, mp) == NULL)
return MDB_FAIL;
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, (int)key->mv_size, (char *)key->mv_data);
assert(i < NUMKEYS(mp));
node = NODEPTR(mp, i);
if (cursor)
CURSOR_TOP(cursor)->mp_ki = i;
mpp->mp_parent = mp;
if ((mp = mdb_get_page(txn, NODEPGNO(node))) == NULL)
return MDB_FAIL;
mpp->mp_pi = i;
mpp->mp_page = mp;
if (cursor && cursor_push_page(cursor, mp) == NULL)
return MDB_FAIL;
if (modify) {
MDB_dhead *dh = ((MDB_dhead *)mp)-1;
if ((rc = mdb_touch(txn, 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_FAIL;
}
DPRINTF("found leaf page %lu for key %.*s", mp->mp_pgno,
key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : 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)) {
DPRINTF("transaction has failed, must abort");
return EINVAL;
} else
root = txn->mt_dbs[dbi].md_root;
if (root == P_INVALID) { /* Tree is empty. */
DPRINTF("tree is empty");
return MDB_NOTFOUND;
}
if ((mpp->mp_page = mdb_get_page(txn, root)) == NULL)
return MDB_FAIL;
DPRINTF("root page has flags 0x%X", 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, 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;
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 ((omp = mdb_get_page(txn, pgno)) == NULL) {
DPRINTF("read overflow page %lu failed", pgno);
return MDB_FAIL;
}
data->mv_data = omp;
return MDB_SUCCESS;
}
int
mdb_get(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data)
{
int rc, exact;
MDB_node *leaf;
MDB_pageparent mpp;
assert(key);
assert(data);
DPRINTF("===> get key [%.*s]", (int)key->mv_size, (char *)key->mv_data);
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
return EINVAL;
}
if ((rc = mdb_search_page(txn, dbi, key, NULL, 0, &mpp)) != MDB_SUCCESS)
return rc;
leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, NULL);
if (leaf && exact) {
/* Return first duplicate data item */
if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
MDB_xcursor mx;
mdb_xcursor_init0(txn, dbi, &mx);
mdb_xcursor_init1(txn, dbi, &mx, leaf);
rc = mdb_search_page(&mx.mx_txn, mx.mx_cursor.mc_dbi, NULL, NULL, 0, &mpp);
if (rc != MDB_SUCCESS)
return rc;
leaf = NODEPTR(mpp.mp_page, 0);
}
rc = mdb_read_data(txn, leaf, data);
} else {
rc = MDB_NOTFOUND;
}
return rc;
}
static int
mdb_sibling(MDB_cursor *cursor, int move_right)
{
int rc;
MDB_node *indx;
MDB_ppage *parent, *top;
MDB_page *mp;
top = CURSOR_TOP(cursor);
if ((parent = SLIST_NEXT(top, mp_entry)) == NULL) {
return MDB_NOTFOUND; /* root has no siblings */
}
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 ((mp = mdb_get_page(cursor->mc_txn, indx->mn_pgno)) == NULL)
return MDB_FAIL;
#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_set_key(MDB_node *node, MDB_val *key)
{
if (key == NULL)
return 0;
key->mv_size = node->mn_ksize;
key->mv_data = NODEKEY(node);
return 0;
}
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_eof) {
return MDB_NOTFOUND;
}
assert(cursor->mc_initialized);
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
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;
}
}
top = CURSOR_TOP(cursor);
mp = top->mp_page;
DPRINTF("cursor_next: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
if (top->mp_ki + 1 >= NUMKEYS(mp)) {
DPRINTF("=====> move to next sibling page");
if (mdb_sibling(cursor, 1) != MDB_SUCCESS) {
cursor->mc_eof = 1;
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);
assert(IS_LEAF(mp));
leaf = NODEPTR(mp, top->mp_ki);
if (data) {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
return rc;
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc != MDB_SUCCESS)
return rc;
}
}
return mdb_set_key(leaf, key);
}
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_initialized);
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
if (op == MDB_PREV || op == MDB_PREV_DUP) {
rc = mdb_cursor_prev(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
if (op != MDB_PREV || rc == MDB_SUCCESS)
return rc;
}
}
top = CURSOR_TOP(cursor);
mp = top->mp_page;
DPRINTF("cursor_prev: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
if (top->mp_ki == 0) {
DPRINTF("=====> move to prev sibling page");
if (mdb_sibling(cursor, 0) != MDB_SUCCESS) {
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_eof = 0;
DPRINTF("==> cursor points to page %lu with %u keys, key index %u",
mp->mp_pgno, NUMKEYS(mp), top->mp_ki);
assert(IS_LEAF(mp));
leaf = NODEPTR(mp, top->mp_ki);
if (data) {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
return rc;
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc != MDB_SUCCESS)
return rc;
}
}
return mdb_set_key(leaf, key);
}
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;
assert(cursor);
assert(key);
assert(key->mv_size > 0);
while (CURSOR_TOP(cursor) != NULL)
cursor_pop_page(cursor);
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);
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) {
DPRINTF("===> 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_initialized = 1;
cursor->mc_eof = 0;
if (data) {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
if (op == MDB_SET || op == MDB_SET_RANGE) {
rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
} else {
int ex2, *ex2p;
MDB_cursor_op op2;
if (op == MDB_GET_BOTH) {
ex2p = &ex2;
op2 = MDB_SET;
} else {
ex2p = NULL;
op2 = MDB_SET_RANGE;
}
rc = mdb_cursor_set(&cursor->mc_xcursor->mx_cursor, data, NULL, op2, ex2p);
if (rc != MDB_SUCCESS)
return rc;
}
}
}
rc = mdb_set_key(leaf, key);
if (rc == MDB_SUCCESS) {
DPRINTF("==> cursor placed on key %.*s",
(int)key->mv_size, (char *)key->mv_data);
;
}
return rc;
}
static int
mdb_cursor_first(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
{
int rc;
MDB_pageparent mpp;
MDB_node *leaf;
while (CURSOR_TOP(cursor) != NULL)
cursor_pop_page(cursor);
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_initialized = 1;
cursor->mc_eof = 0;
if (data) {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc)
return rc;
}
}
return mdb_set_key(leaf, key);
}
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;
while (CURSOR_TOP(cursor) != NULL)
cursor_pop_page(cursor);
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_initialized = 1;
cursor->mc_eof = 0;
top = CURSOR_TOP(cursor);
top->mp_ki = NUMKEYS(top->mp_page) - 1;
if (data) {
if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
return rc;
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
if (rc)
return rc;
}
}
return mdb_set_key(leaf, key);
}
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) {
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_NEXT:
case MDB_NEXT_DUP:
case MDB_NEXT_NODUP:
if (!cursor->mc_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_initialized || cursor->mc_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_LAST:
rc = mdb_cursor_last(cursor, key, data);
break;
default:
DPRINTF("unhandled/unimplemented cursor operation %u", op);
rc = EINVAL;
break;
}
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, 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 */
assert(mp->mp_upper >= mp->mp_lower);
DPRINTF("add node [%.*s] to %s page %lu at index %i, key size %zu",
key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : NULL,
IS_LEAF(mp) ? "leaf" : "branch",
mp->mp_pgno, indx, key ? key->mv_size : 0);
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 MDB_FAIL;
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
node->mn_pgno = 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)
{
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));
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_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
{
MDB_dbi dbn;
mx->mx_txn = *txn;
mx->mx_txn.mt_dbxs = mx->mx_dbxs;
mx->mx_txn.mt_dbs = mx->mx_dbs;
mx->mx_dbxs[0] = txn->mt_dbxs[0];
mx->mx_dbxs[1] = txn->mt_dbxs[1];
if (dbi > 1) {
mx->mx_dbxs[2] = txn->mt_dbxs[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;
SLIST_INIT(&mx->mx_cursor.mc_stack);
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_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;
}
mx->mx_dbs[dbn] = *db;
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_oldest = txn->mt_oldest;
mx->mx_txn.mt_u = txn->mt_u;
}
static void
mdb_xcursor_fini(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
{
txn->mt_next_pgno = mx->mx_txn.mt_next_pgno;
txn->mt_oldest = mx->mx_txn.mt_oldest;
txn->mt_u = mx->mx_txn.mt_u;
txn->mt_dbs[0] = mx->mx_dbs[0];
txn->mt_dbs[1] = mx->mx_dbs[1];
txn->mt_dbxs[0].md_dirty = mx->mx_dbxs[0].md_dirty;
txn->mt_dbxs[1].md_dirty = mx->mx_dbxs[1].md_dirty;
if (dbi > 1) {
txn->mt_dbs[dbi] = mx->mx_dbs[2];
txn->mt_dbxs[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) {
SLIST_INIT(&cursor->mc_stack);
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(txn, dbi, mx);
}
} 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)
{
if (mc == NULL || countp == NULL)
return EINVAL;
if (!(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT))
return EINVAL;
if (!mc->mc_xcursor->mx_cursor.mc_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) {
while(!CURSOR_EMPTY(cursor))
cursor_pop_page(cursor);
if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
mdb_xcursor_fini(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor);
while(!CURSOR_EMPTY(&cursor->mc_xcursor->mx_cursor))
cursor_pop_page(&cursor->mc_xcursor->mx_cursor);
}
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;
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),
(int)key->mv_size, (char *)key->mv_data,
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;
srcnode = NODEPTR(src->mp_page, srcindx);
DPRINTF("moving %s node %u [%.*s] on page %lu to node %u on page %lu",
IS_LEAF(src->mp_page) ? "leaf" : "branch",
srcindx,
(int)srcnode->mn_ksize, (char *)NODEKEY(srcnode),
src->mp_page->mp_pgno,
dstindx, dst->mp_page->mp_pgno);
/* Mark src and dst as dirty. */
if ((rc = mdb_touch(txn, src)) ||
(rc = mdb_touch(txn, dst)))
return rc;;
/* Add the node to the destination page.
*/
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, 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);
/* Update the parent separators.
*/
if (srcindx == 0 && src->mp_pi != 0) {
DPRINTF("update separator for source page %lu to [%.*s]",
src->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
if ((rc = mdb_update_key(src->mp_parent, src->mp_pi,
&key)) != MDB_SUCCESS)
return rc;
}
if (srcindx == 0 && 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 && dst->mp_pi != 0) {
DPRINTF("update separator for destination page %lu to [%.*s]",
dst->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
if ((rc = mdb_update_key(dst->mp_parent, dst->mp_pi,
&key)) != MDB_SUCCESS)
return rc;
}
if (dstindx == 0 && 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, src)) ||
(rc = mdb_touch(txn, dst)))
return rc;
/* Move all nodes from src to dst.
*/
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);
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;
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) {
DPRINTF("tree is completely empty");
txn->mt_dbs[dbi].md_root = P_INVALID;
txn->mt_dbs[dbi].md_depth--;
txn->mt_dbs[dbi].md_leaf_pages--;
} else if (IS_BRANCH(mpp->mp_page) && NUMKEYS(mpp->mp_page) == 1) {
DPRINTF("collapsing root page!");
txn->mt_dbs[dbi].md_root = NODEPGNO(NODEPTR(mpp->mp_page, 0));
if ((root = mdb_get_page(txn, txn->mt_dbs[dbi].md_root)) == NULL)
return MDB_FAIL;
txn->mt_dbs[dbi].md_depth--;
txn->mt_dbs[dbi].md_branch_pages--;
} else
DPRINTF("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.
*/
DPRINTF("reading right neighbor");
node = NODEPTR(mpp->mp_parent, mpp->mp_pi + 1);
if ((npp.mp_page = mdb_get_page(txn, NODEPGNO(node))) == NULL)
return MDB_FAIL;
npp.mp_pi = mpp->mp_pi + 1;
si = 0;
di = NUMKEYS(mpp->mp_page);
} else {
/* There is at least one neighbor to the left.
*/
DPRINTF("reading left neighbor");
node = NODEPTR(mpp->mp_parent, mpp->mp_pi - 1);
if ((npp.mp_page = mdb_get_page(txn, NODEPGNO(node))) == NULL)
return MDB_FAIL;
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 (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_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,
unsigned int flags)
{
int rc, exact;
unsigned int ki;
MDB_node *leaf;
MDB_pageparent mpp;
DPRINTF("========> delete key %.*s", (int)key->mv_size, (char *)key->mv_data);
assert(key != NULL);
if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
return EINVAL;
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
return EINVAL;
}
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 (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
MDB_xcursor mx;
MDB_pageparent mp2;
mdb_xcursor_init0(txn, dbi, &mx);
mdb_xcursor_init1(txn, dbi, &mx, leaf);
if (flags == MDB_DEL_DUP) {
rc = mdb_del(&mx.mx_txn, mx.mx_cursor.mc_dbi, data, NULL, 0);
mdb_xcursor_fini(txn, dbi, &mx);
if (rc != MDB_SUCCESS)
return rc;
/* 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));
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);
top = CURSOR_TOP(&mx.mx_cursor);
if (top != NULL) {
parent = SLIST_NEXT(top, mp_entry);
while (parent != NULL) {
for (i=0; i<NUMKEYS(top->mp_page); i++) {
ni = NODEPTR(top->mp_page, i);
mdb_midl_insert(txn->mt_free_pgs, ni->mn_pgno);
}
if (parent) {
parent->mp_ki++;
if (parent->mp_ki >= NUMKEYS(parent->mp_page)) {
cursor_pop_page(&mx.mx_cursor);
top = CURSOR_TOP(&mx.mx_cursor);
parent = SLIST_NEXT(top, mp_entry);
} else {
ni = NODEPTR(parent->mp_page, parent->mp_ki);
top->mp_page = mdb_get_page(&mx.mx_txn, ni->mn_pgno);
}
}
}
}
mdb_midl_insert(txn->mt_free_pgs, mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi].md_root);
}
}
}
if (data && (rc = mdb_read_data(txn, leaf, data)) != MDB_SUCCESS)
return rc;
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;
MDB_node *node;
MDB_val sepkey, rkey, rdata;
MDB_page *copy;
MDB_dpage *mdp, *rdp, *pdp;
MDB_dhead *dh;
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,
(int)newkey->mv_size, (char *)newkey->mv_data, *newindxp);
if (mdp->h.md_parent == NULL) {
if ((pdp = mdb_new_page(txn, dbi, P_BRANCH, 1)) == NULL)
return MDB_FAIL;
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 (mdb_add_node(txn, dbi, &pdp->p, 0, NULL, NULL,
mdp->p.mp_pgno, 0) != MDB_SUCCESS)
return MDB_FAIL;
} 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 MDB_FAIL;
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);
/* Move half of the keys to the right sibling. */
if ((copy = malloc(txn->mt_env->me_psize)) == NULL)
return MDB_FAIL;
memcpy(copy, &mdp->p, txn->mt_env->me_psize);
memset(&mdp->p.mp_ptrs, 0, txn->mt_env->me_psize - PAGEHDRSZ);
mdp->p.mp_lower = PAGEHDRSZ;
mdp->p.mp_upper = txn->mt_env->me_psize;
split_indx = NUMKEYS(copy) / 2 + 1;
/* 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(copy, split_indx);
sepkey.mv_size = node->mn_ksize;
sepkey.mv_data = NODEKEY(node);
}
DPRINTF("separator is [%.*s]", (int)sepkey.mv_size, (char *)sepkey.mv_data);
/* 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 (rc != MDB_SUCCESS) {
free(copy);
return MDB_FAIL;
}
for (i = j = 0; i <= NUMKEYS(copy); j++) {
if (i < split_indx) {
/* Re-insert in left sibling. */
pdp = mdp;
} else {
/* Insert in right sibling. */
if (i == split_indx)
/* Reset insert index for right sibling. */
j = (i == newindx && ins_new);
pdp = rdp;
}
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;
*mpp = &pdp->p;
} else if (i == NUMKEYS(copy)) {
break;
} else {
node = NODEPTR(copy, 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 = node->mn_pgno;
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, &pdp->p, j, &rkey, &rdata, pgno,flags);
}
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;
MDB_db dummy;
DPRINTF("==> put key %.*s, size %zu, data size %zu",
(int)key->mv_size, (char *)key->mv_data, key->mv_size, data->mv_size);
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 (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
goto put_sub;
}
if (flags == MDB_NOOVERWRITE) {
DPRINTF("duplicate key %.*s",
(int)key->mv_size, (char *)key->mv_data);
return MDB_KEYEXIST;
}
/* same size, just replace it */
if (NODEDSZ(leaf) == data->mv_size) {
memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
goto done;
}
mdb_del_node(mpp.mp_page, ki);
}
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 */
DPRINTF("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++;
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);
/* For sorted dups, the data item at this level is a DB record
* for a child DB; the actual data elements are stored as keys
* in the child DB.
*/
if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
rdata = &xdata;
xdata.mv_size = sizeof(MDB_db);
xdata.mv_data = &dummy;
memset(&dummy, 0, sizeof(dummy));
dummy.md_root = P_INVALID;
} else {
rdata = data;
}
if (SIZELEFT(mpp.mp_page) < mdb_leaf_size(txn->mt_env, key, rdata)) {
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 {
txn->mt_dbs[dbi].md_entries++;
/* 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 (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
MDB_xcursor mx;
leaf = NODEPTR(mpp.mp_page, ki);
put_sub:
mdb_xcursor_init0(txn, dbi, &mx);
mdb_xcursor_init1(txn, dbi, &mx, leaf);
xdata.mv_size = 0;
xdata.mv_data = "";
if (flags == MDB_NODUPDATA)
flags = MDB_NOOVERWRITE;
rc = mdb_put0(&mx.mx_txn, mx.mx_cursor.mc_dbi, data, &xdata, flags);
mdb_xcursor_fini(txn, dbi, &mx);
memcpy(NODEDATA(leaf), &mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi],
sizeof(MDB_db));
}
}
done:
return rc;
}
int
mdb_put(MDB_txn *txn, MDB_dbi dbi,
MDB_val *key, MDB_val *data, unsigned int flags)
{
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 EINVAL;
}
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
return EINVAL;
}
if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA)) != flags)
return EINVAL;
return mdb_put0(txn, dbi, key, data, flags);
}
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)
{
if (env == NULL || arg == NULL)
return EINVAL;
return mdb_stat0(env, &env->me_meta->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_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;
}