1 /* mdb.c - memory-mapped database library */
3 * Copyright 2011 Howard Chu, Symas Corp.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted only as authorized by the OpenLDAP
10 * A copy of this license is available in the file LICENSE in the
11 * top-level directory of the distribution or, alternatively, at
12 * <http://www.OpenLDAP.org/license.html>.
14 * This code is derived from btree.c written by Martin Hedenfalk.
16 * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
18 * Permission to use, copy, modify, and distribute this software for any
19 * purpose with or without fee is hereby granted, provided that the above
20 * copyright notice and this permission notice appear in all copies.
22 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
23 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
25 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
27 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
28 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
30 #include <sys/types.h>
32 #include <sys/queue.h>
33 #include <sys/param.h>
36 #ifdef HAVE_SYS_FILE_H
57 #define ULONG unsigned long
66 #if DEBUG && defined(__GNUC__)
67 # define DPRINTF(fmt, ...) \
68 fprintf(stderr, "%s:%d: " fmt "\n", __func__, __LINE__, ##__VA_ARGS__)
70 # define DPRINTF(...) ((void) 0)
75 #define MDB_MAGIC 0xBEEFC0DE
77 #define MAXKEYSIZE 511
79 #define P_INVALID (~0UL)
81 #define F_ISSET(w, f) (((w) & (f)) == (f))
83 typedef uint16_t indx_t;
85 #define DEFAULT_READERS 126
86 #define DEFAULT_MAPSIZE 1048576
88 /* Lock descriptor stuff */
93 typedef struct MDB_rxbody {
98 #define CACHELINE 64 /* most CPUs. Itanium uses 128 */
101 typedef struct MDB_reader {
103 /* cache line alignment */
104 char pad[CACHELINE-sizeof(MDB_rxbody)];
109 uint32_t mt_version; \
110 pthread_mutex_t mt_mutex; \
112 uint32_t mt_numreaders
113 typedef struct MDB_txbody {
117 typedef struct MDB_txninfo {
119 char pad[CACHELINE-sizeof(MDB_txbody)];
120 pthread_mutex_t mt_wmutex;
121 char pad2[CACHELINE-sizeof(pthread_mutex_t)];
122 MDB_reader mt_readers[1];
125 /* Common header for all page types. Overflow pages
126 * occupy a number of contiguous pages with no
127 * headers on any page after the first.
129 typedef struct MDB_page { /* represents a page of storage */
130 #define mp_pgno mp_p.p_pgno
132 pgno_t p_pgno; /* page number */
135 #define P_BRANCH 0x01 /* branch page */
136 #define P_LEAF 0x02 /* leaf page */
137 #define P_OVERFLOW 0x04 /* overflow page */
138 #define P_META 0x08 /* meta page */
139 #define P_DIRTY 0x10 /* dirty page */
141 #define mp_lower mp_pb.pb.pb_lower
142 #define mp_upper mp_pb.pb.pb_upper
143 #define mp_pages mp_pb.pb_pages
146 indx_t pb_lower; /* lower bound of free space */
147 indx_t pb_upper; /* upper bound of free space */
149 uint32_t pb_pages; /* number of overflow pages */
151 indx_t mp_ptrs[1]; /* dynamic size */
154 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
156 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
157 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
158 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
159 ((env)->me_psize - PAGEHDRSZ))
160 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
161 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
162 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
164 #define OVPAGES(size, psize) (PAGEHDRSZ + size + psize - 1) / psize;
166 typedef struct MDB_db {
170 ULONG md_branch_pages;
172 ULONG md_overflow_pages;
180 typedef struct MDB_meta { /* meta (footer) page content */
183 void *mm_address; /* address for fixed mapping */
184 size_t mm_mapsize; /* size of mmap region */
185 MDB_db mm_dbs[2]; /* first is free space, 2nd is main db */
186 #define mm_psize mm_dbs[0].md_pad
187 #define mm_flags mm_dbs[0].md_flags
188 pgno_t mm_last_pg; /* last used page in file */
189 ULONG mm_txnid; /* txnid that committed this page */
192 typedef struct MDB_dhead { /* a dirty page */
193 STAILQ_ENTRY(MDB_dpage) md_next; /* queue of dirty pages */
195 unsigned md_pi; /* parent index */
199 typedef struct MDB_dpage {
204 STAILQ_HEAD(dirty_queue, MDB_dpage); /* FIXME: use a sorted data structure */
206 typedef struct MDB_oldpages {
207 struct MDB_oldpages *mo_next;
209 pgno_t mo_pages[1]; /* dynamic */
212 typedef struct MDB_pageparent {
218 static MDB_dpage *mdb_alloc_page(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num);
219 static int mdb_touch(MDB_txn *txn, MDB_pageparent *mp);
221 typedef struct MDB_ppage { /* ordered list of pages */
222 SLIST_ENTRY(MDB_ppage) mp_entry;
224 unsigned int mp_ki; /* cursor index on page */
226 SLIST_HEAD(page_stack, MDB_ppage);
228 #define CURSOR_EMPTY(c) SLIST_EMPTY(&(c)->mc_stack)
229 #define CURSOR_TOP(c) SLIST_FIRST(&(c)->mc_stack)
230 #define CURSOR_POP(c) SLIST_REMOVE_HEAD(&(c)->mc_stack, mp_entry)
231 #define CURSOR_PUSH(c,p) SLIST_INSERT_HEAD(&(c)->mc_stack, p, mp_entry)
237 struct page_stack mc_stack; /* stack of parent pages */
239 short mc_initialized; /* 1 if initialized */
240 short mc_eof; /* 1 if end is reached */
241 struct MDB_xcursor *mc_xcursor;
244 #define METAHASHLEN offsetof(MDB_meta, mm_hash)
245 #define METADATA(p) ((void *)((char *)p + PAGEHDRSZ))
247 typedef struct MDB_node {
248 #define mn_pgno mn_p.np_pgno
249 #define mn_dsize mn_p.np_dsize
251 pgno_t np_pgno; /* child page number */
252 uint32_t np_dsize; /* leaf data size */
254 unsigned int mn_flags:4;
255 unsigned int mn_ksize:12; /* key size */
256 #define F_BIGDATA 0x01 /* data put on overflow page */
261 typedef struct MDB_dbx {
263 MDB_cmp_func *md_cmp; /* user compare function */
264 MDB_cmp_func *md_dcmp; /* user dupsort function */
265 MDB_rel_func *md_rel; /* user relocate function */
267 unsigned int md_dirty;
271 pgno_t mt_next_pgno; /* next unallocated page */
275 pgno_t *mt_free_pgs; /* this is an IDL */
277 struct dirty_queue *dirty_queue; /* modified pages */
280 MDB_dbx *mt_dbxs; /* array */
282 unsigned int mt_numdbs;
284 #define MDB_TXN_RDONLY 0x01 /* read-only transaction */
285 #define MDB_TXN_ERROR 0x02 /* an error has occurred */
286 #define MDB_TXN_METOGGLE 0x04 /* used meta page 1 */
287 unsigned int mt_flags;
290 /* Context for sorted-dup records */
291 typedef struct MDB_xcursor {
292 MDB_cursor mx_cursor;
302 unsigned int me_maxreaders;
303 unsigned int me_numdbs;
304 unsigned int me_maxdbs;
307 MDB_txninfo *me_txns;
308 MDB_meta *me_metas[2];
310 MDB_txn *me_txn; /* current write transaction */
312 off_t me_size; /* current file size */
313 unsigned int me_psize;
315 MDB_dbx *me_dbxs; /* array */
317 MDB_oldpages *me_pghead;
318 pthread_key_t me_txkey; /* thread-key for readers */
319 pgno_t me_free_pgs[MDB_IDL_UM_SIZE];
322 #define NODESIZE offsetof(MDB_node, mn_data)
324 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
325 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
326 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
327 #define NODEKEY(node) (void *)((node)->mn_data)
328 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
329 #define NODEPGNO(node) ((node)->mn_pgno)
330 #define NODEDSZ(node) ((node)->mn_dsize)
332 #define MDB_COMMIT_PAGES 64 /* max number of pages to write in one commit */
333 #define MDB_MAXCACHE_DEF 1024 /* max number of pages to keep in cache */
335 static int mdb_search_page_root(MDB_txn *txn,
336 MDB_dbi dbi, MDB_val *key,
337 MDB_cursor *cursor, int modify,
338 MDB_pageparent *mpp);
339 static int mdb_search_page(MDB_txn *txn,
340 MDB_dbi dbi, MDB_val *key,
341 MDB_cursor *cursor, int modify,
342 MDB_pageparent *mpp);
344 static int mdbenv_read_header(MDB_env *env, MDB_meta *meta);
345 static int mdbenv_read_meta(MDB_env *env, int *which);
346 static int mdbenv_write_meta(MDB_txn *txn);
347 static MDB_page *mdb_get_page(MDB_txn *txn, pgno_t pgno);
349 static MDB_node *mdb_search_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp,
350 MDB_val *key, int *exactp, unsigned int *kip);
351 static int mdb_add_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp,
352 indx_t indx, MDB_val *key, MDB_val *data,
353 pgno_t pgno, uint8_t flags);
354 static void mdb_del_node(MDB_page *mp, indx_t indx);
355 static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, unsigned int ki,
356 MDB_pageparent *mpp, MDB_node *leaf);
357 static int mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
359 static int mdb_rebalance(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *mp);
360 static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key);
361 static int mdb_move_node(MDB_txn *txn, MDB_dbi dbi,
362 MDB_pageparent *src, indx_t srcindx,
363 MDB_pageparent *dst, indx_t dstindx);
364 static int mdb_merge(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *src,
365 MDB_pageparent *dst);
366 static int mdb_split(MDB_txn *txn, MDB_dbi dbi, MDB_page **mpp,
367 unsigned int *newindxp, MDB_val *newkey,
368 MDB_val *newdata, pgno_t newpgno);
369 static MDB_dpage *mdb_new_page(MDB_txn *txn, MDB_dbi dbi, uint32_t flags, int num);
371 static void cursor_pop_page(MDB_cursor *cursor);
372 static MDB_ppage *cursor_push_page(MDB_cursor *cursor,
375 static int mdb_set_key(MDB_node *node, MDB_val *key);
376 static int mdb_sibling(MDB_cursor *cursor, int move_right);
377 static int mdb_cursor_next(MDB_cursor *cursor,
378 MDB_val *key, MDB_val *data, MDB_cursor_op op);
379 static int mdb_cursor_prev(MDB_cursor *cursor,
380 MDB_val *key, MDB_val *data, MDB_cursor_op op);
381 static int mdb_cursor_set(MDB_cursor *cursor,
382 MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp);
383 static int mdb_cursor_first(MDB_cursor *cursor,
384 MDB_val *key, MDB_val *data);
385 static int mdb_cursor_last(MDB_cursor *cursor,
386 MDB_val *key, MDB_val *data);
388 static void mdb_xcursor_init0(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
389 static void mdb_xcursor_init1(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx, MDB_db *db);
390 static void mdb_xcursor_fini(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
392 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key,
394 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
396 static int memncmp(const void *s1, size_t n1,
397 const void *s2, size_t n2);
398 static int memnrcmp(const void *s1, size_t n1,
399 const void *s2, size_t n2);
402 memncmp(const void *s1, size_t n1, const void *s2, size_t n2)
404 int diff, len_diff = -1;
407 len_diff = (n1 > n2);
410 diff = memcmp(s1, s2, n1);
411 return diff ? diff : len_diff;
415 memnrcmp(const void *s1, size_t n1, const void *s2, size_t n2)
417 const unsigned char *p1, *p2, *p1_lim;
424 p1 = (const unsigned char *)s1 + n1 - 1;
425 p2 = (const unsigned char *)s2 + n2 - 1;
427 for (p1_lim = (n1 <= n2 ? s1 : s2); *p1 == *p2; p1--, p2--) {
429 return (p1 != s1) ? (p1 != p2) : (p2 != s2) ? -1 : 0;
435 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
437 return txn->mt_dbxs[dbi].md_cmp(a, b);
441 _mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *key1, const MDB_val *key2)
443 if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_REVERSEKEY))
444 return memnrcmp(key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
446 return memncmp((char *)key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
449 /* Allocate new page(s) for writing */
451 mdb_alloc_page(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num)
454 pgno_t pgno = P_INVALID;
455 ULONG oldest = txn->mt_txnid - 2;
457 if (!txn->mt_env->me_pghead && txn->mt_dbs[FREE_DBI].md_root != P_INVALID) {
458 /* See if there's anything in the free DB */
463 mpp.mp_parent = NULL;
465 mdb_search_page(txn, FREE_DBI, NULL, NULL, 0, &mpp);
466 leaf = NODEPTR(mpp.mp_page, 0);
467 kptr = (ULONG *)NODEKEY(leaf);
469 /* It's potentially usable, unless there are still
470 * older readers outstanding. Grab it.
472 if (oldest > *kptr) {
477 mdb_read_data(txn, leaf, &data);
478 idl = (ULONG *)data.mv_data;
479 mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t));
480 mop->mo_next = txn->mt_env->me_pghead;
481 mop->mo_txnid = *kptr;
482 txn->mt_env->me_pghead = mop;
483 memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl));
488 DPRINTF("IDL read txn %lu root %lu num %lu",
489 mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
490 for (i=0; i<idl[0]; i++) {
491 DPRINTF("IDL %lu", idl[i+1]);
495 /* drop this IDL from the DB */
496 mpp.mp_parent = NULL;
498 mdb_search_page(txn, FREE_DBI, NULL, NULL, 1, &mpp);
499 leaf = NODEPTR(mpp.mp_page, 0);
500 mdb_del0(txn, FREE_DBI, 0, &mpp, leaf);
503 if (txn->mt_env->me_pghead) {
505 for (i=0; i<txn->mt_env->me_txns->mt_numreaders; i++) {
506 ULONG mr = txn->mt_env->me_txns->mt_readers[i].mr_txnid;
509 oldest = txn->mt_env->me_txns->mt_readers[i].mr_txnid;
511 if (oldest > txn->mt_env->me_pghead->mo_txnid) {
512 MDB_oldpages *mop = txn->mt_env->me_pghead;
513 txn->mt_oldest = oldest;
515 /* FIXME: For now, always use fresh pages. We
516 * really ought to search the free list for a
521 /* peel pages off tail, so we only have to truncate the list */
522 pgno = MDB_IDL_LAST(mop->mo_pages);
523 if (MDB_IDL_IS_RANGE(mop->mo_pages)) {
525 if (mop->mo_pages[2] > mop->mo_pages[1])
526 mop->mo_pages[0] = 0;
530 if (MDB_IDL_IS_ZERO(mop->mo_pages)) {
531 txn->mt_env->me_pghead = mop->mo_next;
538 if ((dp = malloc(txn->mt_env->me_psize * num + sizeof(MDB_dhead))) == NULL)
541 dp->h.md_parent = parent;
542 dp->h.md_pi = parent_idx;
543 STAILQ_INSERT_TAIL(txn->mt_u.dirty_queue, dp, h.md_next);
544 if (pgno == P_INVALID) {
545 dp->p.mp_pgno = txn->mt_next_pgno;
546 txn->mt_next_pgno += num;
548 dp->p.mp_pgno = pgno;
554 /* Touch a page: make it dirty and re-insert into tree with updated pgno.
557 mdb_touch(MDB_txn *txn, MDB_pageparent *pp)
559 MDB_page *mp = pp->mp_page;
564 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
566 if ((dp = mdb_alloc_page(txn, pp->mp_parent, pp->mp_pi, 1)) == NULL)
568 DPRINTF("touched page %lu -> %lu", mp->mp_pgno, dp->p.mp_pgno);
569 mdb_idl_insert(txn->mt_free_pgs, mp->mp_pgno);
570 pgno = dp->p.mp_pgno;
571 memcpy(&dp->p, mp, txn->mt_env->me_psize);
574 mp->mp_flags |= P_DIRTY;
576 /* Update the page number to new touched page. */
577 if (pp->mp_parent != NULL)
578 NODEPGNO(NODEPTR(pp->mp_parent, pp->mp_pi)) = mp->mp_pgno;
585 mdbenv_sync(MDB_env *env)
588 if (!F_ISSET(env->me_flags, MDB_NOSYNC)) {
589 if (fsync(env->me_fd))
596 mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
601 if ((txn = calloc(1, sizeof(MDB_txn))) == NULL) {
602 DPRINTF("calloc: %s", strerror(errno));
607 txn->mt_flags |= MDB_TXN_RDONLY;
609 txn->mt_u.dirty_queue = calloc(1, sizeof(*txn->mt_u.dirty_queue));
610 if (txn->mt_u.dirty_queue == NULL) {
614 STAILQ_INIT(txn->mt_u.dirty_queue);
616 pthread_mutex_lock(&env->me_txns->mt_wmutex);
617 env->me_txns->mt_txnid++;
618 txn->mt_free_pgs = env->me_free_pgs;
619 txn->mt_free_pgs[0] = 0;
622 txn->mt_txnid = env->me_txns->mt_txnid;
624 MDB_reader *r = pthread_getspecific(env->me_txkey);
627 pthread_mutex_lock(&env->me_txns->mt_mutex);
628 for (i=0; i<env->me_txns->mt_numreaders; i++)
629 if (env->me_txns->mt_readers[i].mr_pid == 0)
631 if (i == env->me_maxreaders) {
632 pthread_mutex_unlock(&env->me_txns->mti_mutex);
635 env->me_txns->mt_readers[i].mr_pid = getpid();
636 env->me_txns->mt_readers[i].mr_tid = pthread_self();
637 r = &env->me_txns->mt_readers[i];
638 pthread_setspecific(env->me_txkey, r);
639 if (i >= env->me_txns->mt_numreaders)
640 env->me_txns->mt_numreaders = i+1;
641 pthread_mutex_unlock(&env->me_txns->mt_mutex);
643 r->mr_txnid = txn->mt_txnid;
644 txn->mt_u.reader = r;
651 if ((rc = mdbenv_read_meta(env, &toggle)) != MDB_SUCCESS) {
656 /* Copy the DB arrays */
657 txn->mt_numdbs = env->me_numdbs;
658 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
659 txn->mt_dbs = malloc(env->me_maxdbs * sizeof(MDB_db));
660 memcpy(txn->mt_dbs, env->me_meta->mm_dbs, 2 * sizeof(MDB_db));
661 if (txn->mt_numdbs > 2)
662 memcpy(txn->mt_dbs+2, env->me_dbs[env->me_db_toggle]+2,
663 (txn->mt_numdbs - 2) * sizeof(MDB_db));
667 txn->mt_flags |= MDB_TXN_METOGGLE;
668 txn->mt_next_pgno = env->me_meta->mm_last_pg+1;
671 DPRINTF("begin transaction %lu on mdbenv %p, root page %lu",
672 txn->mt_txnid, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
679 mdb_txn_abort(MDB_txn *txn)
688 DPRINTF("abort transaction %lu on mdbenv %p, root page %lu",
689 txn->mt_txnid, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
693 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
694 txn->mt_u.reader->mr_txnid = 0;
699 /* Discard all dirty pages. */
700 while (!STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
701 dp = STAILQ_FIRST(txn->mt_u.dirty_queue);
702 STAILQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
705 free(txn->mt_u.dirty_queue);
707 while ((mop = txn->mt_env->me_pghead)) {
708 txn->mt_env->me_pghead = mop->mo_next;
713 env->me_txns->mt_txnid--;
714 for (i=2; i<env->me_numdbs; i++)
715 env->me_dbxs[i].md_dirty = 0;
716 pthread_mutex_unlock(&env->me_txns->mt_wmutex);
723 mdb_txn_commit(MDB_txn *txn)
732 struct iovec iov[MDB_COMMIT_PAGES];
735 assert(txn->mt_env != NULL);
739 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
740 DPRINTF("attempt to commit read-only transaction");
745 if (txn != env->me_txn) {
746 DPRINTF("attempt to commit unknown transaction");
751 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
752 DPRINTF("error flag is set, can't commit");
757 if (STAILQ_EMPTY(txn->mt_u.dirty_queue))
760 DPRINTF("committing transaction %lu on mdbenv %p, root page %lu",
761 txn->mt_txnid, (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
763 /* should only be one record now */
764 if (env->me_pghead) {
768 mop = env->me_pghead;
769 key.mv_size = sizeof(pgno_t);
770 key.mv_data = (char *)&mop->mo_txnid;
771 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
772 data.mv_data = mop->mo_pages;
773 mdb_put(txn, FREE_DBI, &key, &data, 0);
774 free(env->me_pghead);
775 env->me_pghead = NULL;
777 /* save to free list */
778 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
782 /* make sure last page of freeDB is touched and on freelist */
783 key.mv_size = MAXKEYSIZE+1;
785 mpp.mp_parent = NULL;
787 mdb_search_page(txn, FREE_DBI, &key, NULL, 1, &mpp);
792 ULONG *idl = txn->mt_free_pgs;
793 DPRINTF("IDL write txn %lu root %lu num %lu",
794 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
795 for (i=0; i<idl[0]; i++) {
796 DPRINTF("IDL %lu", idl[i+1]);
800 /* write to last page of freeDB */
801 key.mv_size = sizeof(pgno_t);
802 key.mv_data = (char *)&txn->mt_txnid;
803 data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs);
804 data.mv_data = txn->mt_free_pgs;
805 mdb_put(txn, FREE_DBI, &key, &data, 0);
808 /* Update DB root pointers. Their pages have already been
809 * touched so this is all in-place and cannot fail.
813 data.mv_size = sizeof(MDB_db);
815 for (i = 2; i < txn->mt_numdbs; i++) {
816 if (txn->mt_dbxs[i].md_dirty) {
817 data.mv_data = &txn->mt_dbs[i];
818 mdb_put(txn, i, &txn->mt_dbxs[i].md_name, &data, 0);
823 /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
830 STAILQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
831 if (dp->p.mp_pgno != next) {
833 DPRINTF("committing %u dirty pages", n);
834 rc = writev(env->me_fd, iov, n);
838 DPRINTF("short write, filesystem full?");
840 DPRINTF("writev: %s", strerror(errno));
847 lseek(env->me_fd, dp->p.mp_pgno * env->me_psize, SEEK_SET);
848 next = dp->p.mp_pgno;
850 DPRINTF("committing page %lu", dp->p.mp_pgno);
851 iov[n].iov_len = env->me_psize * dp->h.md_num;
852 iov[n].iov_base = &dp->p;
853 size += iov[n].iov_len;
854 next = dp->p.mp_pgno + dp->h.md_num;
855 /* clear dirty flag */
856 dp->p.mp_flags &= ~P_DIRTY;
857 if (++n >= MDB_COMMIT_PAGES) {
866 DPRINTF("committing %u dirty pages", n);
867 rc = writev(env->me_fd, iov, n);
871 DPRINTF("short write, filesystem full?");
873 DPRINTF("writev: %s", strerror(errno));
880 /* Drop the dirty pages.
882 while (!STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
883 dp = STAILQ_FIRST(txn->mt_u.dirty_queue);
884 STAILQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
888 if ((n = mdbenv_sync(env)) != 0 ||
889 (n = mdbenv_write_meta(txn)) != MDB_SUCCESS ||
890 (n = mdbenv_sync(env)) != 0) {
896 /* update the DB tables */
898 int toggle = !env->me_db_toggle;
900 for (i = 2; i < env->me_numdbs; i++) {
901 if (txn->mt_dbxs[i].md_dirty) {
902 env->me_dbs[toggle][i] = txn->mt_dbs[i];
903 txn->mt_dbxs[i].md_dirty = 0;
906 for (i = env->me_numdbs; i < txn->mt_numdbs; i++) {
907 txn->mt_dbxs[i].md_dirty = 0;
908 env->me_dbxs[i] = txn->mt_dbxs[i];
909 env->me_dbs[toggle][i] = txn->mt_dbs[i];
911 env->me_db_toggle = toggle;
912 env->me_numdbs = txn->mt_numdbs;
917 pthread_mutex_unlock(&env->me_txns->mt_wmutex);
918 free(txn->mt_u.dirty_queue);
929 mdbenv_read_header(MDB_env *env, MDB_meta *meta)
938 /* We don't know the page size yet, so use a minimum value.
941 if ((rc = pread(env->me_fd, page, PAGESIZE, 0)) == 0) {
943 } else if (rc != PAGESIZE) {
946 DPRINTF("read: %s", strerror(errno));
950 p = (MDB_page *)page;
952 if (!F_ISSET(p->mp_flags, P_META)) {
953 DPRINTF("page %lu not a meta page", p->mp_pgno);
958 if (m->mm_magic != MDB_MAGIC) {
959 DPRINTF("meta has invalid magic");
963 if (m->mm_version != MDB_VERSION) {
964 DPRINTF("database is version %u, expected version %u",
965 m->mm_version, MDB_VERSION);
966 return MDB_VERSION_MISMATCH;
969 memcpy(meta, m, sizeof(*m));
974 mdbenv_init_meta(MDB_env *env, MDB_meta *meta)
981 DPRINTF("writing new meta page");
982 psize = sysconf(_SC_PAGE_SIZE);
984 meta->mm_magic = MDB_MAGIC;
985 meta->mm_version = MDB_VERSION;
986 meta->mm_psize = psize;
987 meta->mm_last_pg = 1;
988 meta->mm_flags = env->me_flags & 0xffff;
989 #if __BYTE_ORDER == __LITTLE_ENDIAN
990 /* freeDB keys are pgno_t's, must compare in int order */
991 meta->mm_flags |= MDB_REVERSEKEY;
993 meta->mm_dbs[0].md_root = P_INVALID;
994 meta->mm_dbs[1].md_root = P_INVALID;
996 p = calloc(2, psize);
998 p->mp_flags = P_META;
1001 memcpy(m, meta, sizeof(*meta));
1003 q = (MDB_page *)((char *)p + psize);
1006 q->mp_flags = P_META;
1009 memcpy(m, meta, sizeof(*meta));
1011 rc = write(env->me_fd, p, psize * 2);
1013 return (rc == (int)psize * 2) ? MDB_SUCCESS : errno;
1017 mdbenv_write_meta(MDB_txn *txn)
1025 assert(txn != NULL);
1026 assert(txn->mt_env != NULL);
1028 DPRINTF("writing meta page for root page %lu", txn->mt_dbs[MAIN_DBI].md_root);
1032 ptr = (char *)&meta;
1033 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
1034 len = sizeof(MDB_meta) - off;
1037 meta.mm_dbs[0] = txn->mt_dbs[0];
1038 meta.mm_dbs[1] = txn->mt_dbs[1];
1039 meta.mm_last_pg = txn->mt_next_pgno - 1;
1040 meta.mm_txnid = txn->mt_txnid;
1042 if (!F_ISSET(txn->mt_flags, MDB_TXN_METOGGLE))
1043 off += env->me_psize;
1046 lseek(env->me_fd, off, SEEK_SET);
1047 rc = write(env->me_fd, ptr, len);
1049 DPRINTF("write failed, disk error?");
1057 mdbenv_read_meta(MDB_env *env, int *which)
1061 assert(env != NULL);
1063 if (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid)
1066 if (env->me_meta != env->me_metas[toggle])
1067 env->me_meta = env->me_metas[toggle];
1071 DPRINTF("Using meta page %d", toggle);
1077 mdbenv_create(MDB_env **env)
1081 e = calloc(1, sizeof(MDB_env));
1082 if (!e) return ENOMEM;
1084 e->me_maxreaders = DEFAULT_READERS;
1093 mdbenv_set_mapsize(MDB_env *env, size_t size)
1097 env->me_mapsize = size;
1102 mdbenv_set_maxdbs(MDB_env *env, int dbs)
1106 env->me_maxdbs = dbs;
1111 mdbenv_set_maxreaders(MDB_env *env, int readers)
1113 env->me_maxreaders = readers;
1118 mdbenv_get_maxreaders(MDB_env *env, int *readers)
1120 if (!env || !readers)
1122 *readers = env->me_maxreaders;
1127 mdbenv_open2(MDB_env *env, unsigned int flags)
1133 env->me_flags = flags;
1135 memset(&meta, 0, sizeof(meta));
1137 if ((i = mdbenv_read_header(env, &meta)) != 0) {
1140 DPRINTF("new mdbenv");
1144 if (!env->me_mapsize) {
1145 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
1149 if (meta.mm_address && (flags & MDB_FIXEDMAP))
1151 env->me_map = mmap(meta.mm_address, env->me_mapsize, PROT_READ, i,
1153 if (env->me_map == MAP_FAILED)
1157 meta.mm_mapsize = env->me_mapsize;
1158 if (flags & MDB_FIXEDMAP)
1159 meta.mm_address = env->me_map;
1160 i = mdbenv_init_meta(env, &meta);
1161 if (i != MDB_SUCCESS) {
1162 munmap(env->me_map, env->me_mapsize);
1166 env->me_psize = meta.mm_psize;
1168 p = (MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)(MDB_page *)env->me_map;
1169 env->me_metas[0] = METADATA(p);
1170 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize);
1172 if ((i = mdbenv_read_meta(env, NULL)) != 0)
1175 DPRINTF("opened database version %u, pagesize %u",
1176 env->me_meta->mm_version, env->me_psize);
1177 DPRINTF("depth: %u", env->me_meta->mm_dbs[MAIN_DBI].md_depth);
1178 DPRINTF("entries: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_entries);
1179 DPRINTF("branch pages: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_branch_pages);
1180 DPRINTF("leaf pages: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_leaf_pages);
1181 DPRINTF("overflow pages: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_overflow_pages);
1182 DPRINTF("root: %lu", env->me_meta->mm_dbs[MAIN_DBI].md_root);
1188 mdbenv_reader_dest(void *ptr)
1190 MDB_reader *reader = ptr;
1192 reader->mr_txnid = 0;
1197 /* downgrade the exclusive lock on the region back to shared */
1199 mdbenv_share_locks(MDB_env *env)
1201 struct flock lock_info;
1203 env->me_txns->mt_txnid = env->me_meta->mm_txnid;
1205 memset((void *)&lock_info, 0, sizeof(lock_info));
1206 lock_info.l_type = F_RDLCK;
1207 lock_info.l_whence = SEEK_SET;
1208 lock_info.l_start = 0;
1209 lock_info.l_len = 1;
1210 fcntl(env->me_lfd, F_SETLK, &lock_info);
1214 mdbenv_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
1218 struct flock lock_info;
1222 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
1226 /* Try to get exclusive lock. If we succeed, then
1227 * nobody is using the lock region and we should initialize it.
1229 memset((void *)&lock_info, 0, sizeof(lock_info));
1230 lock_info.l_type = F_WRLCK;
1231 lock_info.l_whence = SEEK_SET;
1232 lock_info.l_start = 0;
1233 lock_info.l_len = 1;
1234 rc = fcntl(env->me_lfd, F_SETLK, &lock_info);
1238 lock_info.l_type = F_RDLCK;
1239 rc = fcntl(env->me_lfd, F_SETLK, &lock_info);
1245 size = lseek(env->me_lfd, 0, SEEK_END);
1246 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
1247 if (size < rsize && *excl) {
1248 if (ftruncate(env->me_lfd, rsize) != 0) {
1254 size = rsize - sizeof(MDB_txninfo);
1255 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
1257 env->me_txns = mmap(0, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
1259 if (env->me_txns == MAP_FAILED) {
1264 pthread_mutexattr_t mattr;
1266 pthread_mutexattr_init(&mattr);
1267 pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
1268 pthread_mutex_init(&env->me_txns->mt_mutex, &mattr);
1269 pthread_mutex_init(&env->me_txns->mt_wmutex, &mattr);
1270 env->me_txns->mt_version = MDB_VERSION;
1271 env->me_txns->mt_magic = MDB_MAGIC;
1272 env->me_txns->mt_txnid = 0;
1273 env->me_txns->mt_numreaders = 0;
1276 if (env->me_txns->mt_magic != MDB_MAGIC) {
1277 DPRINTF("lock region has invalid magic");
1281 if (env->me_txns->mt_version != MDB_VERSION) {
1282 DPRINTF("lock region is version %u, expected version %u",
1283 env->me_txns->mt_version, MDB_VERSION);
1284 rc = MDB_VERSION_MISMATCH;
1287 if (errno != EACCES && errno != EAGAIN) {
1301 mdbenv_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
1303 int oflags, rc, len, excl;
1304 char *lpath, *dpath;
1307 lpath = malloc(len + sizeof("/lock.mdb") + len + sizeof("/data.db"));
1310 dpath = lpath + len + sizeof("/lock.mdb");
1311 sprintf(lpath, "%s/lock.mdb", path);
1312 sprintf(dpath, "%s/data.mdb", path);
1314 rc = mdbenv_setup_locks(env, lpath, mode, &excl);
1318 if (F_ISSET(flags, MDB_RDONLY))
1321 oflags = O_RDWR | O_CREAT;
1323 if ((env->me_fd = open(dpath, oflags, mode)) == -1)
1326 if ((rc = mdbenv_open2(env, flags)) != MDB_SUCCESS) {
1330 env->me_path = strdup(path);
1331 DPRINTF("opened dbenv %p", (void *) env);
1332 pthread_key_create(&env->me_txkey, mdbenv_reader_dest);
1334 mdbenv_share_locks(env);
1335 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
1336 env->me_dbs[0] = calloc(env->me_maxdbs, sizeof(MDB_db));
1337 env->me_dbs[1] = calloc(env->me_maxdbs, sizeof(MDB_db));
1347 mdbenv_close(MDB_env *env)
1356 munmap(env->me_map, env->me_mapsize);
1360 size_t size = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
1361 munmap(env->me_txns, size);
1367 /* Search for key within a leaf page, using binary search.
1368 * Returns the smallest entry larger or equal to the key.
1369 * If exactp is non-null, stores whether the found entry was an exact match
1370 * in *exactp (1 or 0).
1371 * If kip is non-null, stores the index of the found entry in *kip.
1372 * If no entry larger or equal to the key is found, returns NULL.
1375 mdb_search_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp, MDB_val *key,
1376 int *exactp, unsigned int *kip)
1384 DPRINTF("searching %u keys in %s page %lu",
1386 IS_LEAF(mp) ? "leaf" : "branch",
1389 assert(NUMKEYS(mp) > 0);
1391 memset(&nodekey, 0, sizeof(nodekey));
1393 low = IS_LEAF(mp) ? 0 : 1;
1394 high = NUMKEYS(mp) - 1;
1395 while (low <= high) {
1396 i = (low + high) >> 1;
1397 node = NODEPTR(mp, i);
1399 nodekey.mv_size = node->mn_ksize;
1400 nodekey.mv_data = NODEKEY(node);
1402 if (txn->mt_dbxs[dbi].md_cmp)
1403 rc = txn->mt_dbxs[dbi].md_cmp(key, &nodekey);
1405 rc = _mdb_cmp(txn, dbi, key, &nodekey);
1408 DPRINTF("found leaf index %u [%.*s], rc = %i",
1409 i, (int)nodekey.mv_size, (char *)nodekey.mv_data, rc);
1411 DPRINTF("found branch index %u [%.*s -> %lu], rc = %i",
1412 i, (int)node->mn_ksize, (char *)NODEKEY(node),
1423 if (rc > 0) { /* Found entry is less than the key. */
1424 i++; /* Skip to get the smallest entry larger than key. */
1425 if (i >= NUMKEYS(mp))
1426 /* There is no entry larger or equal to the key. */
1430 *exactp = (rc == 0);
1431 if (kip) /* Store the key index if requested. */
1434 return NODEPTR(mp, i);
1438 cursor_pop_page(MDB_cursor *cursor)
1442 top = CURSOR_TOP(cursor);
1445 DPRINTF("popped page %lu off cursor %p", top->mp_page->mp_pgno, (void *) cursor);
1451 cursor_push_page(MDB_cursor *cursor, MDB_page *mp)
1455 DPRINTF("pushing page %lu on cursor %p", mp->mp_pgno, (void *) cursor);
1457 if ((ppage = calloc(1, sizeof(MDB_ppage))) == NULL)
1459 ppage->mp_page = mp;
1460 CURSOR_PUSH(cursor, ppage);
1465 mdb_get_page(MDB_txn *txn, pgno_t pgno)
1470 if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && !STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
1472 STAILQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
1473 if (dp->p.mp_pgno == pgno) {
1481 if (pgno > txn->mt_env->me_meta->mm_last_pg)
1483 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
1489 mdb_search_page_root(MDB_txn *txn, MDB_dbi dbi, MDB_val *key,
1490 MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
1492 MDB_page *mp = mpp->mp_page;
1495 if (cursor && cursor_push_page(cursor, mp) == NULL)
1498 while (IS_BRANCH(mp)) {
1502 DPRINTF("branch page %lu has %u keys", mp->mp_pgno, NUMKEYS(mp));
1503 assert(NUMKEYS(mp) > 1);
1504 DPRINTF("found index 0 to page %lu", NODEPGNO(NODEPTR(mp, 0)));
1506 if (key == NULL) /* Initialize cursor to first page. */
1508 else if (key->mv_size > MAXKEYSIZE && key->mv_data == NULL) {
1509 /* cursor to last page */
1513 node = mdb_search_node(txn, dbi, mp, key, &exact, &i);
1515 i = NUMKEYS(mp) - 1;
1523 DPRINTF("following index %u for key %.*s",
1524 i, (int)key->mv_size, (char *)key->mv_data);
1525 assert(i < NUMKEYS(mp));
1526 node = NODEPTR(mp, i);
1529 CURSOR_TOP(cursor)->mp_ki = i;
1531 mpp->mp_parent = mp;
1532 if ((mp = mdb_get_page(txn, NODEPGNO(node))) == NULL)
1537 if (cursor && cursor_push_page(cursor, mp) == NULL)
1541 MDB_dhead *dh = ((MDB_dhead *)mp)-1;
1542 if ((rc = mdb_touch(txn, mpp)) != 0)
1544 dh = ((MDB_dhead *)mpp->mp_page)-1;
1545 dh->md_parent = mpp->mp_parent;
1546 dh->md_pi = mpp->mp_pi;
1553 DPRINTF("internal error, index points to a %02X page!?",
1558 DPRINTF("found leaf page %lu for key %.*s", mp->mp_pgno,
1559 key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : NULL);
1564 /* Search for the page a given key should be in.
1565 * Stores a pointer to the found page in *mpp.
1566 * If key is NULL, search for the lowest page (used by mdb_cursor_first).
1567 * If cursor is non-null, pushes parent pages on the cursor stack.
1568 * If modify is true, visited pages are updated with new page numbers.
1571 mdb_search_page(MDB_txn *txn, MDB_dbi dbi, MDB_val *key,
1572 MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
1577 /* Choose which root page to start with. If a transaction is given
1578 * use the root page from the transaction, otherwise read the last
1579 * committed root page.
1581 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
1582 DPRINTF("transaction has failed, must abort");
1585 root = txn->mt_dbs[dbi].md_root;
1587 if (root == P_INVALID) { /* Tree is empty. */
1588 DPRINTF("tree is empty");
1589 return MDB_NOTFOUND;
1592 if ((mpp->mp_page = mdb_get_page(txn, root)) == NULL)
1595 DPRINTF("root page has flags 0x%X", mpp->mp_page->mp_flags);
1598 /* For sub-databases, update main root first */
1599 if (dbi > MAIN_DBI && !txn->mt_dbxs[dbi].md_dirty) {
1601 rc = mdb_search_page(txn, 0, &txn->mt_dbxs[dbi].md_name,
1605 txn->mt_dbxs[dbi].md_dirty = 1;
1607 if (!F_ISSET(mpp->mp_page->mp_flags, P_DIRTY)) {
1608 mpp->mp_parent = NULL;
1610 if ((rc = mdb_touch(txn, mpp)))
1612 txn->mt_dbs[dbi].md_root = mpp->mp_page->mp_pgno;
1616 return mdb_search_page_root(txn, dbi, key, cursor, modify, mpp);
1620 mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
1622 MDB_page *omp; /* overflow mpage */
1625 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
1626 data->mv_size = leaf->mn_dsize;
1627 data->mv_data = NODEDATA(leaf);
1631 /* Read overflow data.
1633 data->mv_size = leaf->mn_dsize;
1634 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
1635 if ((omp = mdb_get_page(txn, pgno)) == NULL) {
1636 DPRINTF("read overflow page %lu failed", pgno);
1639 data->mv_data = omp;
1645 mdb_get(MDB_txn *txn, MDB_dbi dbi,
1646 MDB_val *key, MDB_val *data)
1654 DPRINTF("===> get key [%.*s]", (int)key->mv_size, (char *)key->mv_data);
1656 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
1660 if ((rc = mdb_search_page(txn, dbi, key, NULL, 0, &mpp)) != MDB_SUCCESS)
1663 leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, NULL);
1664 if (leaf && exact) {
1665 /* Return first duplicate data item */
1666 if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
1669 mdb_xcursor_init0(txn, dbi, &mx);
1670 mdb_xcursor_init1(txn, dbi, &mx, NODEDATA(leaf));
1671 rc = mdb_search_page(&mx.mx_txn, mx.mx_txn.mt_numdbs-1, NULL, NULL, 0, &mpp);
1672 if (rc != MDB_SUCCESS)
1674 leaf = NODEPTR(mpp.mp_page, 0);
1676 rc = mdb_read_data(txn, leaf, data);
1685 mdb_sibling(MDB_cursor *cursor, int move_right)
1689 MDB_ppage *parent, *top;
1692 top = CURSOR_TOP(cursor);
1693 if ((parent = SLIST_NEXT(top, mp_entry)) == NULL) {
1694 return MDB_NOTFOUND; /* root has no siblings */
1697 DPRINTF("parent page is page %lu, index %u",
1698 parent->mp_page->mp_pgno, parent->mp_ki);
1700 cursor_pop_page(cursor);
1701 if (move_right ? (parent->mp_ki + 1 >= NUMKEYS(parent->mp_page))
1702 : (parent->mp_ki == 0)) {
1703 DPRINTF("no more keys left, moving to %s sibling",
1704 move_right ? "right" : "left");
1705 if ((rc = mdb_sibling(cursor, move_right)) != MDB_SUCCESS)
1707 parent = CURSOR_TOP(cursor);
1713 DPRINTF("just moving to %s index key %u",
1714 move_right ? "right" : "left", parent->mp_ki);
1716 assert(IS_BRANCH(parent->mp_page));
1718 indx = NODEPTR(parent->mp_page, parent->mp_ki);
1719 if ((mp = mdb_get_page(cursor->mc_txn, indx->mn_pgno)) == NULL)
1722 mp->parent = parent->mp_page;
1723 mp->parent_index = parent->mp_ki;
1726 cursor_push_page(cursor, mp);
1732 mdb_set_key(MDB_node *node, MDB_val *key)
1737 key->mv_size = node->mn_ksize;
1738 key->mv_data = NODEKEY(node);
1744 mdb_cursor_next(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op op)
1751 if (cursor->mc_eof) {
1752 return MDB_NOTFOUND;
1755 assert(cursor->mc_initialized);
1757 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
1758 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
1759 rc = mdb_cursor_next(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
1760 if (op != MDB_NEXT || rc == MDB_SUCCESS)
1765 top = CURSOR_TOP(cursor);
1768 DPRINTF("cursor_next: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
1770 if (top->mp_ki + 1 >= NUMKEYS(mp)) {
1771 DPRINTF("=====> move to next sibling page");
1772 if (mdb_sibling(cursor, 1) != MDB_SUCCESS) {
1774 return MDB_NOTFOUND;
1776 top = CURSOR_TOP(cursor);
1778 DPRINTF("next page is %lu, key index %u", mp->mp_pgno, top->mp_ki);
1782 DPRINTF("==> cursor points to page %lu with %u keys, key index %u",
1783 mp->mp_pgno, NUMKEYS(mp), top->mp_ki);
1785 assert(IS_LEAF(mp));
1786 leaf = NODEPTR(mp, top->mp_ki);
1789 if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
1792 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
1793 mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, NODEDATA(leaf));
1794 rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
1795 if (rc != MDB_SUCCESS)
1800 return mdb_set_key(leaf, key);
1804 mdb_cursor_prev(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op op)
1811 assert(cursor->mc_initialized);
1813 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
1814 if (op == MDB_PREV || op == MDB_PREV_DUP) {
1815 rc = mdb_cursor_next(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
1816 if (op != MDB_PREV || rc == MDB_SUCCESS)
1821 top = CURSOR_TOP(cursor);
1824 DPRINTF("cursor_prev: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
1826 if (top->mp_ki == 0) {
1827 DPRINTF("=====> move to prev sibling page");
1828 if (mdb_sibling(cursor, 0) != MDB_SUCCESS) {
1829 return MDB_NOTFOUND;
1831 top = CURSOR_TOP(cursor);
1833 top->mp_ki = NUMKEYS(mp) - 1;
1834 DPRINTF("prev page is %lu, key index %u", mp->mp_pgno, top->mp_ki);
1840 DPRINTF("==> cursor points to page %lu with %u keys, key index %u",
1841 mp->mp_pgno, NUMKEYS(mp), top->mp_ki);
1843 assert(IS_LEAF(mp));
1844 leaf = NODEPTR(mp, top->mp_ki);
1847 if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
1850 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
1851 mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, NODEDATA(leaf));
1852 rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
1853 if (rc != MDB_SUCCESS)
1858 return mdb_set_key(leaf, key);
1862 mdb_cursor_set(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
1863 MDB_cursor_op op, int *exactp)
1872 assert(key->mv_size > 0);
1874 while (CURSOR_TOP(cursor) != NULL)
1875 cursor_pop_page(cursor);
1877 rc = mdb_search_page(cursor->mc_txn, cursor->mc_dbi, key, cursor, 0, &mpp);
1878 if (rc != MDB_SUCCESS)
1880 assert(IS_LEAF(mpp.mp_page));
1882 top = CURSOR_TOP(cursor);
1883 leaf = mdb_search_node(cursor->mc_txn, cursor->mc_dbi, mpp.mp_page, key, exactp, &top->mp_ki);
1884 if (exactp != NULL && !*exactp) {
1885 /* MDB_SET specified and not an exact match. */
1886 return MDB_NOTFOUND;
1890 DPRINTF("===> inexact leaf not found, goto sibling");
1891 if ((rc = mdb_sibling(cursor, 1)) != MDB_SUCCESS)
1892 return rc; /* no entries matched */
1893 top = CURSOR_TOP(cursor);
1895 mpp.mp_page = top->mp_page;
1896 assert(IS_LEAF(mpp.mp_page));
1897 leaf = NODEPTR(mpp.mp_page, 0);
1900 cursor->mc_initialized = 1;
1904 if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
1907 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
1908 mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, NODEDATA(leaf));
1909 if (op == MDB_SET || op == MDB_SET_RANGE) {
1910 rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
1914 if (op == MDB_GET_BOTH) {
1919 op2 = MDB_SET_RANGE;
1921 rc = mdb_cursor_set(&cursor->mc_xcursor->mx_cursor, data, NULL, op2, ex2p);
1922 if (rc != MDB_SUCCESS)
1928 rc = mdb_set_key(leaf, key);
1929 if (rc == MDB_SUCCESS) {
1930 DPRINTF("==> cursor placed on key %.*s",
1931 (int)key->mv_size, (char *)key->mv_data);
1939 mdb_cursor_first(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
1945 while (CURSOR_TOP(cursor) != NULL)
1946 cursor_pop_page(cursor);
1948 rc = mdb_search_page(cursor->mc_txn, cursor->mc_dbi, NULL, cursor, 0, &mpp);
1949 if (rc != MDB_SUCCESS)
1951 assert(IS_LEAF(mpp.mp_page));
1953 leaf = NODEPTR(mpp.mp_page, 0);
1954 cursor->mc_initialized = 1;
1958 if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
1961 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
1962 mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, NODEDATA(leaf));
1963 rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
1968 return mdb_set_key(leaf, key);
1972 mdb_cursor_last(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
1980 while (CURSOR_TOP(cursor) != NULL)
1981 cursor_pop_page(cursor);
1983 lkey.mv_size = MAXKEYSIZE+1;
1984 lkey.mv_data = NULL;
1986 rc = mdb_search_page(cursor->mc_txn, cursor->mc_dbi, &lkey, cursor, 0, &mpp);
1987 if (rc != MDB_SUCCESS)
1989 assert(IS_LEAF(mpp.mp_page));
1991 leaf = NODEPTR(mpp.mp_page, NUMKEYS(mpp.mp_page)-1);
1992 cursor->mc_initialized = 1;
1995 top = CURSOR_TOP(cursor);
1996 top->mp_ki = NUMKEYS(top->mp_page) - 1;
1999 if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
2002 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
2003 mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, NODEDATA(leaf));
2004 rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
2010 return mdb_set_key(leaf, key);
2014 mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
2024 case MDB_GET_BOTH_RANGE:
2032 if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
2034 } else if (op != MDB_SET_RANGE)
2035 rc = mdb_cursor_set(cursor, key, data, op, NULL);
2037 rc = mdb_cursor_set(cursor, key, data, op, &exact);
2041 case MDB_NEXT_NODUP:
2042 if (!cursor->mc_initialized)
2043 rc = mdb_cursor_first(cursor, key, data);
2045 rc = mdb_cursor_next(cursor, key, data, op);
2049 case MDB_PREV_NODUP:
2050 if (!cursor->mc_initialized || cursor->mc_eof)
2051 rc = mdb_cursor_last(cursor, key, data);
2053 rc = mdb_cursor_prev(cursor, key, data, op);
2056 rc = mdb_cursor_first(cursor, key, data);
2059 rc = mdb_cursor_last(cursor, key, data);
2062 DPRINTF("unhandled/unimplemented cursor operation %u", op);
2070 /* Allocate a page and initialize it
2073 mdb_new_page(MDB_txn *txn, MDB_dbi dbi, uint32_t flags, int num)
2077 if ((dp = mdb_alloc_page(txn, NULL, 0, num)) == NULL)
2079 DPRINTF("allocated new mpage %lu, page size %u",
2080 dp->p.mp_pgno, txn->mt_env->me_psize);
2081 dp->p.mp_flags = flags | P_DIRTY;
2082 dp->p.mp_lower = PAGEHDRSZ;
2083 dp->p.mp_upper = txn->mt_env->me_psize;
2085 if (IS_BRANCH(&dp->p))
2086 txn->mt_dbs[dbi].md_branch_pages++;
2087 else if (IS_LEAF(&dp->p))
2088 txn->mt_dbs[dbi].md_leaf_pages++;
2089 else if (IS_OVERFLOW(&dp->p)) {
2090 txn->mt_dbs[dbi].md_overflow_pages += num;
2091 dp->p.mp_pages = num;
2098 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
2102 sz = LEAFSIZE(key, data);
2103 if (data->mv_size >= env->me_psize / MDB_MINKEYS) {
2104 /* put on overflow page */
2105 sz -= data->mv_size - sizeof(pgno_t);
2108 return sz + sizeof(indx_t);
2112 mdb_branch_size(MDB_env *env, MDB_val *key)
2117 if (sz >= env->me_psize / MDB_MINKEYS) {
2118 /* put on overflow page */
2119 /* not implemented */
2120 /* sz -= key->size - sizeof(pgno_t); */
2123 return sz + sizeof(indx_t);
2127 mdb_add_node(MDB_txn *txn, MDB_dbi dbi, MDB_page *mp, indx_t indx,
2128 MDB_val *key, MDB_val *data, pgno_t pgno, uint8_t flags)
2131 size_t node_size = NODESIZE;
2134 MDB_dpage *ofp = NULL; /* overflow page */
2136 assert(mp->mp_upper >= mp->mp_lower);
2138 DPRINTF("add node [%.*s] to %s page %lu at index %i, key size %zu",
2139 key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : NULL,
2140 IS_LEAF(mp) ? "leaf" : "branch",
2141 mp->mp_pgno, indx, key ? key->mv_size : 0);
2144 node_size += key->mv_size;
2148 if (F_ISSET(flags, F_BIGDATA)) {
2149 /* Data already on overflow page. */
2150 node_size += sizeof(pgno_t);
2151 } else if (data->mv_size >= txn->mt_env->me_psize / MDB_MINKEYS) {
2152 int ovpages = OVPAGES(data->mv_size, txn->mt_env->me_psize);
2153 /* Put data on overflow page. */
2154 DPRINTF("data size is %zu, put on overflow page",
2156 node_size += sizeof(pgno_t);
2157 if ((ofp = mdb_new_page(txn, dbi, P_OVERFLOW, ovpages)) == NULL)
2159 DPRINTF("allocated overflow page %lu", ofp->p.mp_pgno);
2162 node_size += data->mv_size;
2166 if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
2167 DPRINTF("not enough room in page %lu, got %u ptrs",
2168 mp->mp_pgno, NUMKEYS(mp));
2169 DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
2170 mp->mp_upper - mp->mp_lower);
2171 DPRINTF("node size = %zu", node_size);
2175 /* Move higher pointers up one slot. */
2176 for (i = NUMKEYS(mp); i > indx; i--)
2177 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
2179 /* Adjust free space offsets. */
2180 ofs = mp->mp_upper - node_size;
2181 assert(ofs >= mp->mp_lower + sizeof(indx_t));
2182 mp->mp_ptrs[indx] = ofs;
2184 mp->mp_lower += sizeof(indx_t);
2186 /* Write the node data. */
2187 node = NODEPTR(mp, indx);
2188 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
2189 node->mn_flags = flags;
2191 node->mn_dsize = data->mv_size;
2193 node->mn_pgno = pgno;
2196 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
2201 if (F_ISSET(flags, F_BIGDATA))
2202 memcpy(node->mn_data + key->mv_size, data->mv_data,
2205 memcpy(node->mn_data + key->mv_size, data->mv_data,
2208 memcpy(node->mn_data + key->mv_size, &ofp->p.mp_pgno,
2210 memcpy(METADATA(&ofp->p), data->mv_data, data->mv_size);
2218 mdb_del_node(MDB_page *mp, indx_t indx)
2221 indx_t i, j, numkeys, ptr;
2225 DPRINTF("delete node %u on %s page %lu", indx,
2226 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno);
2227 assert(indx < NUMKEYS(mp));
2229 node = NODEPTR(mp, indx);
2230 sz = NODESIZE + node->mn_ksize;
2232 if (F_ISSET(node->mn_flags, F_BIGDATA))
2233 sz += sizeof(pgno_t);
2235 sz += NODEDSZ(node);
2238 ptr = mp->mp_ptrs[indx];
2239 numkeys = NUMKEYS(mp);
2240 for (i = j = 0; i < numkeys; i++) {
2242 mp->mp_ptrs[j] = mp->mp_ptrs[i];
2243 if (mp->mp_ptrs[i] < ptr)
2244 mp->mp_ptrs[j] += sz;
2249 base = (char *)mp + mp->mp_upper;
2250 memmove(base + sz, base, ptr - mp->mp_upper);
2252 mp->mp_lower -= sizeof(indx_t);
2257 mdb_xcursor_init0(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
2262 mx->mx_txn.mt_dbxs = mx->mx_dbxs;
2263 mx->mx_txn.mt_dbs = mx->mx_dbs;
2264 mx->mx_dbxs[0] = txn->mt_dbxs[0];
2265 mx->mx_dbxs[1] = txn->mt_dbxs[1];
2267 mx->mx_dbxs[2] = txn->mt_dbxs[dbi];
2272 mx->mx_dbxs[dbn+1].md_parent = dbn;
2273 mx->mx_dbxs[dbn+1].md_cmp = mx->mx_dbxs[dbn].md_dcmp;
2274 mx->mx_dbxs[dbn+1].md_rel = mx->mx_dbxs[dbn].md_rel;
2275 mx->mx_dbxs[dbn+1].md_dirty = 0;
2276 mx->mx_txn.mt_numdbs = dbn+2;
2278 SLIST_INIT(&mx->mx_cursor.mc_stack);
2279 mx->mx_cursor.mc_txn = &mx->mx_txn;
2280 mx->mx_cursor.mc_dbi = dbn+1;
2284 mdb_xcursor_init1(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx, MDB_db *db)
2286 mx->mx_dbs[0] = txn->mt_dbs[0];
2287 mx->mx_dbs[1] = txn->mt_dbs[1];
2289 mx->mx_dbs[2] = txn->mt_dbs[dbi];
2290 mx->mx_dbs[3] = *db;
2292 mx->mx_dbs[2] = *db;
2297 mdb_xcursor_fini(MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
2299 txn->mt_dbs[0] = mx->mx_dbs[0];
2300 txn->mt_dbs[1] = mx->mx_dbs[1];
2301 txn->mt_dbxs[0].md_dirty = mx->mx_dbxs[0].md_dirty;
2302 txn->mt_dbxs[1].md_dirty = mx->mx_dbxs[1].md_dirty;
2304 txn->mt_dbs[dbi] = mx->mx_dbs[2];
2305 txn->mt_dbxs[2].md_dirty = mx->mx_dbxs[2].md_dirty;
2310 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
2313 size_t size = sizeof(MDB_cursor);
2315 if (txn == NULL || ret == NULL || !dbi || dbi >= txn->mt_numdbs)
2318 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
2319 size += sizeof(MDB_xcursor);
2321 if ((cursor = calloc(1, size)) != NULL) {
2322 SLIST_INIT(&cursor->mc_stack);
2323 cursor->mc_dbi = dbi;
2324 cursor->mc_txn = txn;
2325 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
2326 MDB_xcursor *mx = (MDB_xcursor *)(cursor + 1);
2327 cursor->mc_xcursor = mx;
2328 mdb_xcursor_init0(txn, dbi, mx);
2340 mdb_cursor_close(MDB_cursor *cursor)
2342 if (cursor != NULL) {
2343 while(!CURSOR_EMPTY(cursor))
2344 cursor_pop_page(cursor);
2345 if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
2346 mdb_xcursor_fini(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor);
2347 while(!CURSOR_EMPTY(&cursor->mc_xcursor->mx_cursor))
2348 cursor_pop_page(&cursor->mc_xcursor->mx_cursor);
2356 mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key)
2358 indx_t ptr, i, numkeys;
2364 node = NODEPTR(mp, indx);
2365 ptr = mp->mp_ptrs[indx];
2366 DPRINTF("update key %u (ofs %u) [%.*s] to [%.*s] on page %lu",
2368 (int)node->mn_ksize, (char *)NODEKEY(node),
2369 (int)key->mv_size, (char *)key->mv_data,
2372 delta = key->mv_size - node->mn_ksize;
2374 if (delta > 0 && SIZELEFT(mp) < delta) {
2375 DPRINTF("OUCH! Not enough room, delta = %d", delta);
2379 numkeys = NUMKEYS(mp);
2380 for (i = 0; i < numkeys; i++) {
2381 if (mp->mp_ptrs[i] <= ptr)
2382 mp->mp_ptrs[i] -= delta;
2385 base = (char *)mp + mp->mp_upper;
2386 len = ptr - mp->mp_upper + NODESIZE;
2387 memmove(base - delta, base, len);
2388 mp->mp_upper -= delta;
2390 node = NODEPTR(mp, indx);
2391 node->mn_ksize = key->mv_size;
2394 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
2399 /* Move a node from src to dst.
2402 mdb_move_node(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *src, indx_t srcindx,
2403 MDB_pageparent *dst, indx_t dstindx)
2409 srcnode = NODEPTR(src->mp_page, srcindx);
2410 DPRINTF("moving %s node %u [%.*s] on page %lu to node %u on page %lu",
2411 IS_LEAF(src->mp_page) ? "leaf" : "branch",
2413 (int)srcnode->mn_ksize, (char *)NODEKEY(srcnode),
2414 src->mp_page->mp_pgno,
2415 dstindx, dst->mp_page->mp_pgno);
2417 /* Mark src and dst as dirty. */
2418 if ((rc = mdb_touch(txn, src)) ||
2419 (rc = mdb_touch(txn, dst)))
2422 /* Add the node to the destination page.
2424 key.mv_size = srcnode->mn_ksize;
2425 key.mv_data = NODEKEY(srcnode);
2426 data.mv_size = NODEDSZ(srcnode);
2427 data.mv_data = NODEDATA(srcnode);
2428 rc = mdb_add_node(txn, dbi, dst->mp_page, dstindx, &key, &data, NODEPGNO(srcnode),
2430 if (rc != MDB_SUCCESS)
2433 /* Delete the node from the source page.
2435 mdb_del_node(src->mp_page, srcindx);
2437 /* Update the parent separators.
2439 if (srcindx == 0 && src->mp_pi != 0) {
2440 DPRINTF("update separator for source page %lu to [%.*s]",
2441 src->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
2442 if ((rc = mdb_update_key(src->mp_parent, src->mp_pi,
2443 &key)) != MDB_SUCCESS)
2447 if (srcindx == 0 && IS_BRANCH(src->mp_page)) {
2449 nullkey.mv_size = 0;
2450 assert(mdb_update_key(src->mp_page, 0, &nullkey) == MDB_SUCCESS);
2453 if (dstindx == 0 && dst->mp_pi != 0) {
2454 DPRINTF("update separator for destination page %lu to [%.*s]",
2455 dst->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
2456 if ((rc = mdb_update_key(dst->mp_parent, dst->mp_pi,
2457 &key)) != MDB_SUCCESS)
2461 if (dstindx == 0 && IS_BRANCH(dst->mp_page)) {
2463 nullkey.mv_size = 0;
2464 assert(mdb_update_key(dst->mp_page, 0, &nullkey) == MDB_SUCCESS);
2471 mdb_merge(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *src, MDB_pageparent *dst)
2480 DPRINTF("merging page %lu and %lu", src->mp_page->mp_pgno, dst->mp_page->mp_pgno);
2482 assert(txn != NULL);
2483 assert(src->mp_parent); /* can't merge root page */
2484 assert(dst->mp_parent);
2486 /* Mark src and dst as dirty. */
2487 if ((rc = mdb_touch(txn, src)) ||
2488 (rc = mdb_touch(txn, dst)))
2491 /* Move all nodes from src to dst.
2493 for (i = 0; i < NUMKEYS(src->mp_page); i++) {
2494 srcnode = NODEPTR(src->mp_page, i);
2496 key.mv_size = srcnode->mn_ksize;
2497 key.mv_data = NODEKEY(srcnode);
2498 data.mv_size = NODEDSZ(srcnode);
2499 data.mv_data = NODEDATA(srcnode);
2500 rc = mdb_add_node(txn, dbi, dst->mp_page, NUMKEYS(dst->mp_page), &key,
2501 &data, NODEPGNO(srcnode), srcnode->mn_flags);
2502 if (rc != MDB_SUCCESS)
2506 DPRINTF("dst page %lu now has %u keys (%.1f%% filled)",
2507 dst->mp_page->mp_pgno, NUMKEYS(dst->mp_page), (float)PAGEFILL(txn->mt_env, dst->mp_page) / 10);
2509 /* Unlink the src page from parent.
2511 mdb_del_node(src->mp_parent, src->mp_pi);
2512 if (src->mp_pi == 0) {
2514 if ((rc = mdb_update_key(src->mp_parent, 0, &key)) != MDB_SUCCESS)
2518 if (IS_LEAF(src->mp_page))
2519 txn->mt_dbs[dbi].md_leaf_pages--;
2521 txn->mt_dbs[dbi].md_branch_pages--;
2523 mpp.mp_page = src->mp_parent;
2524 dh = (MDB_dhead *)src->mp_parent;
2526 mpp.mp_parent = dh->md_parent;
2527 mpp.mp_pi = dh->md_pi;
2529 return mdb_rebalance(txn, dbi, &mpp);
2532 #define FILL_THRESHOLD 250
2535 mdb_rebalance(MDB_txn *txn, MDB_dbi dbi, MDB_pageparent *mpp)
2540 indx_t si = 0, di = 0;
2542 assert(txn != NULL);
2543 assert(mpp != NULL);
2545 DPRINTF("rebalancing %s page %lu (has %u keys, %.1f%% full)",
2546 IS_LEAF(mpp->mp_page) ? "leaf" : "branch",
2547 mpp->mp_page->mp_pgno, NUMKEYS(mpp->mp_page), (float)PAGEFILL(txn->mt_env, mpp->mp_page) / 10);
2549 if (PAGEFILL(txn->mt_env, mpp->mp_page) >= FILL_THRESHOLD) {
2550 DPRINTF("no need to rebalance page %lu, above fill threshold",
2551 mpp->mp_page->mp_pgno);
2555 if (mpp->mp_parent == NULL) {
2556 if (NUMKEYS(mpp->mp_page) == 0) {
2557 DPRINTF("tree is completely empty");
2558 txn->mt_dbs[dbi].md_root = P_INVALID;
2559 txn->mt_dbs[dbi].md_depth--;
2560 txn->mt_dbs[dbi].md_leaf_pages--;
2561 } else if (IS_BRANCH(mpp->mp_page) && NUMKEYS(mpp->mp_page) == 1) {
2562 DPRINTF("collapsing root page!");
2563 txn->mt_dbs[dbi].md_root = NODEPGNO(NODEPTR(mpp->mp_page, 0));
2564 if ((root = mdb_get_page(txn, txn->mt_dbs[dbi].md_root)) == NULL)
2566 txn->mt_dbs[dbi].md_depth--;
2567 txn->mt_dbs[dbi].md_branch_pages--;
2569 DPRINTF("root page doesn't need rebalancing");
2573 /* The parent (branch page) must have at least 2 pointers,
2574 * otherwise the tree is invalid.
2576 assert(NUMKEYS(mpp->mp_parent) > 1);
2578 /* Leaf page fill factor is below the threshold.
2579 * Try to move keys from left or right neighbor, or
2580 * merge with a neighbor page.
2585 if (mpp->mp_pi == 0) {
2586 /* We're the leftmost leaf in our parent.
2588 DPRINTF("reading right neighbor");
2589 node = NODEPTR(mpp->mp_parent, mpp->mp_pi + 1);
2590 if ((npp.mp_page = mdb_get_page(txn, NODEPGNO(node))) == NULL)
2592 npp.mp_pi = mpp->mp_pi + 1;
2594 di = NUMKEYS(mpp->mp_page);
2596 /* There is at least one neighbor to the left.
2598 DPRINTF("reading left neighbor");
2599 node = NODEPTR(mpp->mp_parent, mpp->mp_pi - 1);
2600 if ((npp.mp_page = mdb_get_page(txn, NODEPGNO(node))) == NULL)
2602 npp.mp_pi = mpp->mp_pi - 1;
2603 si = NUMKEYS(npp.mp_page) - 1;
2606 npp.mp_parent = mpp->mp_parent;
2608 DPRINTF("found neighbor page %lu (%u keys, %.1f%% full)",
2609 npp.mp_page->mp_pgno, NUMKEYS(npp.mp_page), (float)PAGEFILL(txn->mt_env, npp.mp_page) / 10);
2611 /* If the neighbor page is above threshold and has at least two
2612 * keys, move one key from it.
2614 * Otherwise we should try to merge them.
2616 if (PAGEFILL(txn->mt_env, npp.mp_page) >= FILL_THRESHOLD && NUMKEYS(npp.mp_page) >= 2)
2617 return mdb_move_node(txn, dbi, &npp, si, mpp, di);
2618 else { /* FIXME: if (has_enough_room()) */
2619 if (mpp->mp_pi == 0)
2620 return mdb_merge(txn, dbi, &npp, mpp);
2622 return mdb_merge(txn, dbi, mpp, &npp);
2627 mdb_del0(MDB_txn *txn, MDB_dbi dbi, unsigned int ki, MDB_pageparent *mpp, MDB_node *leaf)
2631 /* add overflow pages to free list */
2632 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
2636 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
2637 ovpages = OVPAGES(NODEDSZ(leaf), txn->mt_env->me_psize);
2638 for (i=0; i<ovpages; i++) {
2639 DPRINTF("freed ov page %lu", pg);
2640 mdb_idl_insert(txn->mt_free_pgs, pg);
2644 mdb_del_node(mpp->mp_page, ki);
2645 txn->mt_dbs[dbi].md_entries--;
2646 rc = mdb_rebalance(txn, dbi, mpp);
2647 if (rc != MDB_SUCCESS)
2648 txn->mt_flags |= MDB_TXN_ERROR;
2654 mdb_del(MDB_txn *txn, MDB_dbi dbi,
2655 MDB_val *key, MDB_val *data,
2663 DPRINTF("========> delete key %.*s", (int)key->mv_size, (char *)key->mv_data);
2665 assert(key != NULL);
2667 if (txn == NULL || dbi >= txn->mt_numdbs)
2670 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2674 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
2678 mpp.mp_parent = NULL;
2680 if ((rc = mdb_search_page(txn, dbi, key, NULL, 1, &mpp)) != MDB_SUCCESS)
2683 leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, &ki);
2684 if (leaf == NULL || !exact) {
2685 return MDB_NOTFOUND;
2688 if (data && (rc = mdb_read_data(txn, leaf, data)) != MDB_SUCCESS)
2691 if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
2695 mdb_xcursor_init0(txn, dbi, &mx);
2696 mdb_xcursor_init1(txn, dbi, &mx, NODEDATA(leaf));
2697 if (flags == MDB_DEL_DUP) {
2698 rc = mdb_del(&mx.mx_txn, mx.mx_cursor.mc_dbi, data, NULL, 0);
2699 if (rc != MDB_SUCCESS)
2701 mdb_xcursor_fini(txn, dbi, &mx);
2702 /* If sub-DB still has entries, we're done */
2703 if (mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi].md_root != P_INVALID)
2705 /* otherwise fall thru and delete the sub-db */
2707 /* add all the child DB's pages to the free list */
2708 rc = mdb_search_page(&mx.mx_txn, mx.mx_cursor.mc_dbi,
2709 NULL, &mx.mx_cursor, 0, &mp2);
2710 if (rc == MDB_SUCCESS) {
2711 MDB_ppage *top, *parent;
2715 cursor_pop_page(&mx.mx_cursor);
2716 top = CURSOR_TOP(&mx.mx_cursor);
2718 parent = SLIST_NEXT(top, mp_entry);
2719 while (parent != NULL) {
2720 for (i=0; i<NUMKEYS(top->mp_page); i++) {
2721 ni = NODEPTR(top->mp_page, i);
2722 mdb_idl_insert(txn->mt_free_pgs, ni->mn_pgno);
2726 if (parent->mp_ki >= NUMKEYS(parent->mp_page)) {
2727 cursor_pop_page(&mx.mx_cursor);
2728 top = CURSOR_TOP(&mx.mx_cursor);
2729 parent = SLIST_NEXT(top, mp_entry);
2731 ni = NODEPTR(parent->mp_page, parent->mp_ki);
2732 top->mp_page = mdb_get_page(&mx.mx_txn, ni->mn_pgno);
2737 mdb_idl_insert(txn->mt_free_pgs, mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi].md_root);
2742 return mdb_del0(txn, dbi, ki, &mpp, leaf);
2745 /* Split page <*mpp>, and insert <key,(data|newpgno)> in either left or
2746 * right sibling, at index <*newindxp> (as if unsplit). Updates *mpp and
2747 * *newindxp with the actual values after split, ie if *mpp and *newindxp
2748 * refer to a node in the new right sibling page.
2751 mdb_split(MDB_txn *txn, MDB_dbi dbi, MDB_page **mpp, unsigned int *newindxp,
2752 MDB_val *newkey, MDB_val *newdata, pgno_t newpgno)
2755 int rc = MDB_SUCCESS, ins_new = 0;
2758 unsigned int i, j, split_indx;
2760 MDB_val sepkey, rkey, rdata;
2762 MDB_dpage *mdp, *rdp, *pdp;
2765 assert(txn != NULL);
2767 dh = ((MDB_dhead *)*mpp) - 1;
2768 mdp = (MDB_dpage *)dh;
2769 newindx = *newindxp;
2771 DPRINTF("-----> splitting %s page %lu and adding [%.*s] at index %i",
2772 IS_LEAF(&mdp->p) ? "leaf" : "branch", mdp->p.mp_pgno,
2773 (int)newkey->mv_size, (char *)newkey->mv_data, *newindxp);
2775 if (mdp->h.md_parent == NULL) {
2776 if ((pdp = mdb_new_page(txn, dbi, P_BRANCH, 1)) == NULL)
2779 mdp->h.md_parent = &pdp->p;
2780 txn->mt_dbs[dbi].md_root = pdp->p.mp_pgno;
2781 DPRINTF("root split! new root = %lu", pdp->p.mp_pgno);
2782 txn->mt_dbs[dbi].md_depth++;
2784 /* Add left (implicit) pointer. */
2785 if (mdb_add_node(txn, dbi, &pdp->p, 0, NULL, NULL,
2786 mdp->p.mp_pgno, 0) != MDB_SUCCESS)
2789 DPRINTF("parent branch page is %lu", mdp->h.md_parent->mp_pgno);
2792 /* Create a right sibling. */
2793 if ((rdp = mdb_new_page(txn, dbi, mdp->p.mp_flags, 1)) == NULL)
2795 rdp->h.md_parent = mdp->h.md_parent;
2796 rdp->h.md_pi = mdp->h.md_pi + 1;
2797 DPRINTF("new right sibling: page %lu", rdp->p.mp_pgno);
2799 /* Move half of the keys to the right sibling. */
2800 if ((copy = malloc(txn->mt_env->me_psize)) == NULL)
2802 memcpy(copy, &mdp->p, txn->mt_env->me_psize);
2803 memset(&mdp->p.mp_ptrs, 0, txn->mt_env->me_psize - PAGEHDRSZ);
2804 mdp->p.mp_lower = PAGEHDRSZ;
2805 mdp->p.mp_upper = txn->mt_env->me_psize;
2807 split_indx = NUMKEYS(copy) / 2 + 1;
2809 /* First find the separating key between the split pages.
2811 memset(&sepkey, 0, sizeof(sepkey));
2812 if (newindx == split_indx) {
2813 sepkey.mv_size = newkey->mv_size;
2814 sepkey.mv_data = newkey->mv_data;
2816 node = NODEPTR(copy, split_indx);
2817 sepkey.mv_size = node->mn_ksize;
2818 sepkey.mv_data = NODEKEY(node);
2821 DPRINTF("separator is [%.*s]", (int)sepkey.mv_size, (char *)sepkey.mv_data);
2823 /* Copy separator key to the parent.
2825 if (SIZELEFT(rdp->h.md_parent) < mdb_branch_size(txn->mt_env, &sepkey)) {
2826 rc = mdb_split(txn, dbi, &rdp->h.md_parent, &rdp->h.md_pi,
2827 &sepkey, NULL, rdp->p.mp_pgno);
2829 /* Right page might now have changed parent.
2830 * Check if left page also changed parent.
2832 if (rdp->h.md_parent != mdp->h.md_parent &&
2833 mdp->h.md_pi >= NUMKEYS(mdp->h.md_parent)) {
2834 mdp->h.md_parent = rdp->h.md_parent;
2835 mdp->h.md_pi = rdp->h.md_pi - 1;
2838 rc = mdb_add_node(txn, dbi, rdp->h.md_parent, rdp->h.md_pi,
2839 &sepkey, NULL, rdp->p.mp_pgno, 0);
2841 if (rc != MDB_SUCCESS) {
2846 for (i = j = 0; i <= NUMKEYS(copy); j++) {
2847 if (i < split_indx) {
2848 /* Re-insert in left sibling. */
2851 /* Insert in right sibling. */
2852 if (i == split_indx)
2853 /* Reset insert index for right sibling. */
2854 j = (i == newindx && ins_new);
2858 if (i == newindx && !ins_new) {
2859 /* Insert the original entry that caused the split. */
2860 rkey.mv_data = newkey->mv_data;
2861 rkey.mv_size = newkey->mv_size;
2862 if (IS_LEAF(&mdp->p)) {
2863 rdata.mv_data = newdata->mv_data;
2864 rdata.mv_size = newdata->mv_size;
2871 /* Update page and index for the new key. */
2874 } else if (i == NUMKEYS(copy)) {
2877 node = NODEPTR(copy, i);
2878 rkey.mv_data = NODEKEY(node);
2879 rkey.mv_size = node->mn_ksize;
2880 if (IS_LEAF(&mdp->p)) {
2881 rdata.mv_data = NODEDATA(node);
2882 rdata.mv_size = node->mn_dsize;
2884 pgno = node->mn_pgno;
2885 flags = node->mn_flags;
2890 if (!IS_LEAF(&mdp->p) && j == 0) {
2891 /* First branch index doesn't need key data. */
2895 rc = mdb_add_node(txn, dbi, &pdp->p, j, &rkey, &rdata, pgno,flags);
2903 mdb_put(MDB_txn *txn, MDB_dbi dbi,
2904 MDB_val *key, MDB_val *data, unsigned int flags)
2906 int rc = MDB_SUCCESS, exact;
2910 MDB_val xdata, *rdata;
2913 assert(key != NULL);
2914 assert(data != NULL);
2919 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2923 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
2927 DPRINTF("==> put key %.*s, size %zu, data size %zu",
2928 (int)key->mv_size, (char *)key->mv_data, key->mv_size, data->mv_size);
2930 mpp.mp_parent = NULL;
2932 rc = mdb_search_page(txn, dbi, key, NULL, 1, &mpp);
2933 if (rc == MDB_SUCCESS) {
2934 leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, &ki);
2935 if (leaf && exact) {
2936 if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
2939 if (flags == MDB_NOOVERWRITE) {
2940 DPRINTF("duplicate key %.*s",
2941 (int)key->mv_size, (char *)key->mv_data);
2942 return MDB_KEYEXIST;
2944 /* same size, just replace it */
2945 if (NODEDSZ(leaf) == data->mv_size) {
2946 memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
2949 mdb_del_node(mpp.mp_page, ki);
2951 if (leaf == NULL) { /* append if not found */
2952 ki = NUMKEYS(mpp.mp_page);
2953 DPRINTF("appending key at index %i", ki);
2955 } else if (rc == MDB_NOTFOUND) {
2957 /* new file, just write a root leaf page */
2958 DPRINTF("allocating new root leaf page");
2959 if ((dp = mdb_new_page(txn, dbi, P_LEAF, 1)) == NULL) {
2962 mpp.mp_page = &dp->p;
2963 txn->mt_dbs[dbi].md_root = mpp.mp_page->mp_pgno;
2964 txn->mt_dbs[dbi].md_depth++;
2970 assert(IS_LEAF(mpp.mp_page));
2971 DPRINTF("there are %u keys, should insert new key at index %i",
2972 NUMKEYS(mpp.mp_page), ki);
2974 /* For sorted dups, the data item at this level is a DB record
2975 * for a child DB; the actual data elements are stored as keys
2978 if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
2980 xdata.mv_size = sizeof(MDB_db);
2981 xdata.mv_data = &dummy;
2982 memset(&dummy, 0, sizeof(dummy));
2983 dummy.md_root = P_INVALID;
2988 if (SIZELEFT(mpp.mp_page) < mdb_leaf_size(txn->mt_env, key, data)) {
2989 rc = mdb_split(txn, dbi, &mpp.mp_page, &ki, key, data, P_INVALID);
2991 /* There is room already in this leaf page. */
2992 rc = mdb_add_node(txn, dbi, mpp.mp_page, ki, key, data, 0, 0);
2995 if (rc != MDB_SUCCESS)
2996 txn->mt_flags |= MDB_TXN_ERROR;
2998 txn->mt_dbs[dbi].md_entries++;
2999 /* Now store the actual data in the child DB. Note that we're
3000 * storing the user data in the keys field, so there are strict
3001 * size limits on dupdata. The actual data fields of the child
3002 * DB are all zero size.
3004 if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
3007 leaf = NODEPTR(mpp.mp_page, ki);
3009 mdb_xcursor_init0(txn, dbi, &mx);
3010 mdb_xcursor_init1(txn, dbi, &mx, NODEDATA(leaf));
3013 if (flags == MDB_NODUPDATA)
3014 flags = MDB_NOOVERWRITE;
3015 rc = mdb_put(&mx.mx_txn, mx.mx_txn.mt_numdbs-1, data, &xdata, flags);
3016 mdb_xcursor_fini(txn, dbi, &mx);
3025 mdbenv_get_flags(MDB_env *env, unsigned int *arg)
3030 *arg = env->me_flags;
3035 mdbenv_get_path(MDB_env *env, const char **arg)
3040 *arg = env->me_path;
3045 mdbenv_stat(MDB_env *env, MDB_stat *arg)
3047 if (env == NULL || arg == NULL)
3050 arg->ms_psize = env->me_psize;
3051 arg->ms_depth = env->me_meta->mm_dbs[MAIN_DBI].md_depth;
3052 arg->ms_branch_pages = env->me_meta->mm_dbs[MAIN_DBI].md_branch_pages;
3053 arg->ms_leaf_pages = env->me_meta->mm_dbs[MAIN_DBI].md_leaf_pages;
3054 arg->ms_overflow_pages = env->me_meta->mm_dbs[MAIN_DBI].md_overflow_pages;
3055 arg->ms_entries = env->me_meta->mm_dbs[MAIN_DBI].md_entries;
3060 int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
3073 /* Is the DB already open? */
3075 for (i=2; i<txn->mt_numdbs; i++) {
3076 if (len == txn->mt_dbxs[i].md_name.mv_size &&
3077 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
3083 if (txn->mt_numdbs >= txn->mt_env->me_maxdbs - 1)
3086 /* Find the DB info */
3088 key.mv_data = (void *)name;
3089 rc = mdb_get(txn, MAIN_DBI, &key, &data);
3091 /* Create if requested */
3092 if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
3094 data.mv_size = sizeof(MDB_db);
3095 data.mv_data = &dummy;
3096 memset(&dummy, 0, sizeof(dummy));
3097 dummy.md_root = P_INVALID;
3098 dummy.md_flags = flags & 0xffff;
3099 rc = mdb_put(txn, 0, &key, &data, 0);
3102 /* OK, got info, add to table */
3103 if (rc == MDB_SUCCESS) {
3104 txn->mt_dbxs[txn->mt_numdbs].md_name.mv_data = strdup(name);
3105 txn->mt_dbxs[txn->mt_numdbs].md_name.mv_size = len;
3106 txn->mt_dbxs[txn->mt_numdbs].md_cmp = NULL;
3107 txn->mt_dbxs[txn->mt_numdbs].md_dcmp = NULL;
3108 txn->mt_dbxs[txn->mt_numdbs].md_rel = NULL;
3109 txn->mt_dbxs[txn->mt_numdbs].md_parent = MAIN_DBI;
3110 txn->mt_dbxs[txn->mt_numdbs].md_dirty = 0;
3111 memcpy(&txn->mt_dbs[txn->mt_numdbs], data.mv_data, sizeof(MDB_db));
3112 *dbi = txn->mt_numdbs;
3119 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
3121 if (txn == NULL || arg == NULL)
3124 arg->ms_psize = txn->mt_env->me_psize;
3125 arg->ms_depth = txn->mt_dbs[dbi].md_depth;
3126 arg->ms_branch_pages = txn->mt_dbs[dbi].md_branch_pages;
3127 arg->ms_leaf_pages = txn->mt_dbs[dbi].md_leaf_pages;
3128 arg->ms_overflow_pages = txn->mt_dbs[dbi].md_overflow_pages;
3129 arg->ms_entries = txn->mt_dbs[dbi].md_entries;
3134 void mdb_close(MDB_txn *txn, MDB_dbi dbi)
3137 if (dbi <= MAIN_DBI || dbi >= txn->mt_numdbs)
3139 ptr = txn->mt_dbxs[dbi].md_name.mv_data;
3140 txn->mt_dbxs[dbi].md_name.mv_data = NULL;
3141 txn->mt_dbxs[dbi].md_name.mv_size = 0;