2 * @brief memory-mapped database library
4 * A Btree-based database management library modeled loosely on the
5 * BerkeleyDB API, but much simplified.
8 * Copyright 2011 Howard Chu, Symas Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted only as authorized by the OpenLDAP
15 * A copy of this license is available in the file LICENSE in the
16 * top-level directory of the distribution or, alternatively, at
17 * <http://www.OpenLDAP.org/license.html>.
19 * This code is derived from btree.c written by Martin Hedenfalk.
21 * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
23 * Permission to use, copy, modify, and distribute this software for any
24 * purpose with or without fee is hereby granted, provided that the above
25 * copyright notice and this permission notice appear in all copies.
27 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
28 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
30 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
32 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
33 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
35 #include <sys/types.h>
37 #include <sys/param.h>
43 #ifdef HAVE_SYS_FILE_H
67 #if (__BYTE_ORDER == __LITTLE_ENDIAN) == (__BYTE_ORDER == __BIG_ENDIAN)
68 # error "Unknown or unsupported endianness (__BYTE_ORDER)"
69 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
70 # error "Two's complement, reasonably sized integer types, please"
73 /** @defgroup internal MDB Internals
76 /** @defgroup compat Windows Compatibility Macros
77 * A bunch of macros to minimize the amount of platform-specific ifdefs
78 * needed throughout the rest of the code. When the features this library
79 * needs are similar enough to POSIX to be hidden in a one-or-two line
80 * replacement, this macro approach is used.
84 #define pthread_t DWORD
85 #define pthread_mutex_t HANDLE
86 #define pthread_key_t DWORD
87 #define pthread_self() GetCurrentThreadId()
88 #define pthread_key_create(x,y) (*(x) = TlsAlloc())
89 #define pthread_key_delete(x) TlsFree(x)
90 #define pthread_getspecific(x) TlsGetValue(x)
91 #define pthread_setspecific(x,y) TlsSetValue(x,y)
92 #define pthread_mutex_unlock(x) ReleaseMutex(x)
93 #define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE)
94 #define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex)
95 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex)
96 #define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex)
97 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex)
98 #define getpid() GetCurrentProcessId()
99 #define fdatasync(fd) (!FlushFileBuffers(fd))
100 #define ErrCode() GetLastError()
101 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
102 #define close(fd) CloseHandle(fd)
103 #define munmap(ptr,len) UnmapViewOfFile(ptr)
105 /** Lock the reader mutex.
107 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
108 /** Unlock the reader mutex.
110 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
112 /** Lock the writer mutex.
113 * Only a single write transaction is allowed at a time. Other writers
114 * will block waiting for this mutex.
116 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
117 /** Unlock the writer mutex.
119 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
121 /** Get the error code for the last failed system function.
123 #define ErrCode() errno
125 /** An abstraction for a file handle.
126 * On POSIX systems file handles are small integers. On Windows
127 * they're opaque pointers.
131 /** A value for an invalid file handle.
132 * Mainly used to initialize file variables and signify that they are
135 #define INVALID_HANDLE_VALUE (-1)
137 /** Get the size of a memory page for the system.
138 * This is the basic size that the platform's memory manager uses, and is
139 * fundamental to the use of memory-mapped files.
141 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
147 /** A flag for opening a file and requesting synchronous data writes.
148 * This is only used when writing a meta page. It's not strictly needed;
149 * we could just do a normal write and then immediately perform a flush.
150 * But if this flag is available it saves us an extra system call.
152 * @note If O_DSYNC is undefined but exists in /usr/include,
153 * preferably set some compiler flag to get the definition.
154 * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
157 # define MDB_DSYNC O_DSYNC
161 /** A page number in the database.
162 * Note that 64 bit page numbers are overkill, since pages themselves
163 * already represent 12-13 bits of addressable memory, and the OS will
164 * always limit applications to a maximum of 63 bits of address space.
166 * @note In the #MDB_node structure, we only store 48 bits of this value,
167 * which thus limits us to only 60 bits of addressable data.
169 typedef ULONG pgno_t;
171 /** A transaction ID.
172 * See struct MDB_txn.mt_txnid for details.
174 typedef ULONG txnid_t;
176 /** @defgroup debug Debug Macros
180 /** Enable debug output.
181 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
182 * read from and written to the database (used for free space management).
187 #if !(__STDC_VERSION__ >= 199901L || defined(__GNUC__))
188 # define DPRINTF (void) /* Vararg macros may be unsupported */
190 /** Print a debug message with printf formatting. */
191 # define DPRINTF(fmt, ...) /**< Requires 2 or more args */ \
192 fprintf(stderr, "%s:%d:(%p) " fmt "\n", __func__, __LINE__, pthread_self(), __VA_ARGS__)
194 # define DPRINTF(fmt, ...) ((void) 0)
196 /** Print a debug string.
197 * The string is printed literally, with no format processing.
199 #define DPUTS(arg) DPRINTF("%s", arg)
202 /** A default memory page size.
203 * The actual size is platform-dependent, but we use this for
204 * boot-strapping. We probably should not be using this any more.
205 * The #GET_PAGESIZE() macro is used to get the actual size.
207 * Note that we don't currently support Huge pages. On Linux,
208 * regular data files cannot use Huge pages, and in general
209 * Huge pages aren't actually pageable. We rely on the OS
210 * demand-pager to read our data and page it out when memory
211 * pressure from other processes is high. So until OSs have
212 * actual paging support for Huge pages, they're not viable.
214 #define PAGESIZE 4096
216 /** The minimum number of keys required in a database page.
217 * Setting this to a larger value will place a smaller bound on the
218 * maximum size of a data item. Data items larger than this size will
219 * be pushed into overflow pages instead of being stored directly in
220 * the B-tree node. This value used to default to 4. With a page size
221 * of 4096 bytes that meant that any item larger than 1024 bytes would
222 * go into an overflow page. That also meant that on average 2-3KB of
223 * each overflow page was wasted space. The value cannot be lower than
224 * 2 because then there would no longer be a tree structure. With this
225 * value, items larger than 2KB will go into overflow pages, and on
226 * average only 1KB will be wasted.
228 #define MDB_MINKEYS 2
230 /** A stamp that identifies a file as an MDB file.
231 * There's nothing special about this value other than that it is easily
232 * recognizable, and it will reflect any byte order mismatches.
234 #define MDB_MAGIC 0xBEEFC0DE
236 /** The version number for a database's file format. */
237 #define MDB_VERSION 1
239 /** The maximum size of a key in the database.
240 * While data items have essentially unbounded size, we require that
241 * keys all fit onto a regular page. This limit could be raised a bit
242 * further if needed; to something just under #PAGESIZE / #MDB_MINKEYS.
244 #define MAXKEYSIZE 511
249 * This is used for printing a hex dump of a key's contents.
251 #define DKBUF char kbuf[(MAXKEYSIZE*2+1)]
252 /** Display a key in hex.
254 * Invoke a function to display a key in hex.
256 #define DKEY(x) mdb_dkey(x, kbuf)
258 #define DKBUF typedef int dummy_kbuf /* so we can put ';' after */
262 /** @defgroup lazylock Lazy Locking
263 * Macros for locks that are't actually needed.
264 * The DB view is always consistent because all writes are wrapped in
265 * the wmutex. Finer-grained locks aren't necessary.
269 /** Use lazy locking. I.e., don't lock these accesses at all. */
273 /** Grab the reader lock */
274 #define LAZY_MUTEX_LOCK(x)
275 /** Release the reader lock */
276 #define LAZY_MUTEX_UNLOCK(x)
277 /** Release the DB table reader/writer lock */
278 #define LAZY_RWLOCK_UNLOCK(x)
279 /** Grab the DB table write lock */
280 #define LAZY_RWLOCK_WRLOCK(x)
281 /** Grab the DB table read lock */
282 #define LAZY_RWLOCK_RDLOCK(x)
283 /** Declare the DB table rwlock. Should not be followed by ';'. */
284 #define LAZY_RWLOCK_DEF(x)
285 /** Initialize the DB table rwlock */
286 #define LAZY_RWLOCK_INIT(x,y)
287 /** Destroy the DB table rwlock */
288 #define LAZY_RWLOCK_DESTROY(x)
290 #define LAZY_MUTEX_LOCK(x) pthread_mutex_lock(x)
291 #define LAZY_MUTEX_UNLOCK(x) pthread_mutex_unlock(x)
292 #define LAZY_RWLOCK_UNLOCK(x) pthread_rwlock_unlock(x)
293 #define LAZY_RWLOCK_WRLOCK(x) pthread_rwlock_wrlock(x)
294 #define LAZY_RWLOCK_RDLOCK(x) pthread_rwlock_rdlock(x)
295 #define LAZY_RWLOCK_DEF(x) pthread_rwlock_t x
296 #define LAZY_RWLOCK_INIT(x,y) pthread_rwlock_init(x,y)
297 #define LAZY_RWLOCK_DESTROY(x) pthread_rwlock_destroy(x)
301 /** An invalid page number.
302 * Mainly used to denote an empty tree.
304 #define P_INVALID (~0UL)
306 /** Test if a flag \b f is set in a flag word \b w. */
307 #define F_ISSET(w, f) (((w) & (f)) == (f))
309 /** Used for offsets within a single page.
310 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
313 typedef uint16_t indx_t;
315 /** Default size of memory map.
316 * This is certainly too small for any actual applications. Apps should always set
317 * the size explicitly using #mdb_env_set_mapsize().
319 #define DEFAULT_MAPSIZE 1048576
321 /** @defgroup readers Reader Lock Table
322 * Readers don't acquire any locks for their data access. Instead, they
323 * simply record their transaction ID in the reader table. The reader
324 * mutex is needed just to find an empty slot in the reader table. The
325 * slot's address is saved in thread-specific data so that subsequent read
326 * transactions started by the same thread need no further locking to proceed.
328 * Since the database uses multi-version concurrency control, readers don't
329 * actually need any locking. This table is used to keep track of which
330 * readers are using data from which old transactions, so that we'll know
331 * when a particular old transaction is no longer in use. Old transactions
332 * that have discarded any data pages can then have those pages reclaimed
333 * for use by a later write transaction.
335 * The lock table is constructed such that reader slots are aligned with the
336 * processor's cache line size. Any slot is only ever used by one thread.
337 * This alignment guarantees that there will be no contention or cache
338 * thrashing as threads update their own slot info, and also eliminates
339 * any need for locking when accessing a slot.
341 * A writer thread will scan every slot in the table to determine the oldest
342 * outstanding reader transaction. Any freed pages older than this will be
343 * reclaimed by the writer. The writer doesn't use any locks when scanning
344 * this table. This means that there's no guarantee that the writer will
345 * see the most up-to-date reader info, but that's not required for correct
346 * operation - all we need is to know the upper bound on the oldest reader,
347 * we don't care at all about the newest reader. So the only consequence of
348 * reading stale information here is that old pages might hang around a
349 * while longer before being reclaimed. That's actually good anyway, because
350 * the longer we delay reclaiming old pages, the more likely it is that a
351 * string of contiguous pages can be found after coalescing old pages from
352 * many old transactions together.
354 * @todo We don't actually do such coalescing yet, we grab pages from one
355 * old transaction at a time.
358 /** Number of slots in the reader table.
359 * This value was chosen somewhat arbitrarily. 126 readers plus a
360 * couple mutexes fit exactly into 8KB on my development machine.
361 * Applications should set the table size using #mdb_env_set_maxreaders().
363 #define DEFAULT_READERS 126
365 /** The size of a CPU cache line in bytes. We want our lock structures
366 * aligned to this size to avoid false cache line sharing in the
368 * This value works for most CPUs. For Itanium this should be 128.
374 /** The information we store in a single slot of the reader table.
375 * In addition to a transaction ID, we also record the process and
376 * thread ID that owns a slot, so that we can detect stale information,
377 * e.g. threads or processes that went away without cleaning up.
378 * @note We currently don't check for stale records. We simply re-init
379 * the table when we know that we're the only process opening the
382 typedef struct MDB_rxbody {
383 /** The current Transaction ID when this transaction began.
384 * Multiple readers that start at the same time will probably have the
385 * same ID here. Again, it's not important to exclude them from
386 * anything; all we need to know is which version of the DB they
387 * started from so we can avoid overwriting any data used in that
388 * particular version.
391 /** The process ID of the process owning this reader txn. */
393 /** The thread ID of the thread owning this txn. */
397 /** The actual reader record, with cacheline padding. */
398 typedef struct MDB_reader {
401 /** shorthand for mrb_txnid */
402 #define mr_txnid mru.mrx.mrb_txnid
403 #define mr_pid mru.mrx.mrb_pid
404 #define mr_tid mru.mrx.mrb_tid
405 /** cache line alignment */
406 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
410 /** The header for the reader table.
411 * The table resides in a memory-mapped file. (This is a different file
412 * than is used for the main database.)
414 * For POSIX the actual mutexes reside in the shared memory of this
415 * mapped file. On Windows, mutexes are named objects allocated by the
416 * kernel; we store the mutex names in this mapped file so that other
417 * processes can grab them. This same approach will also be used on
418 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
419 * process-shared POSIX mutexes.
421 typedef struct MDB_txbody {
422 /** Stamp identifying this as an MDB lock file. It must be set
425 /** Version number of this lock file. Must be set to #MDB_VERSION. */
426 uint32_t mtb_version;
430 /** Mutex protecting access to this table.
431 * This is the reader lock that #LOCK_MUTEX_R acquires.
433 pthread_mutex_t mtb_mutex;
435 /** The ID of the last transaction committed to the database.
436 * This is recorded here only for convenience; the value can always
437 * be determined by reading the main database meta pages.
440 /** The number of slots that have been used in the reader table.
441 * This always records the maximum count, it is not decremented
442 * when readers release their slots.
444 unsigned mtb_numreaders;
445 /** The ID of the most recent meta page in the database.
446 * This is recorded here only for convenience; the value can always
447 * be determined by reading the main database meta pages.
449 uint32_t mtb_me_toggle;
452 /** The actual reader table definition. */
453 typedef struct MDB_txninfo {
456 #define mti_magic mt1.mtb.mtb_magic
457 #define mti_version mt1.mtb.mtb_version
458 #define mti_mutex mt1.mtb.mtb_mutex
459 #define mti_rmname mt1.mtb.mtb_rmname
460 #define mti_txnid mt1.mtb.mtb_txnid
461 #define mti_numreaders mt1.mtb.mtb_numreaders
462 #define mti_me_toggle mt1.mtb.mtb_me_toggle
463 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
468 #define mti_wmname mt2.mt2_wmname
470 pthread_mutex_t mt2_wmutex;
471 #define mti_wmutex mt2.mt2_wmutex
473 char pad[(sizeof(pthread_mutex_t)+CACHELINE-1) & ~(CACHELINE-1)];
475 MDB_reader mti_readers[1];
479 /** Common header for all page types.
480 * Overflow pages occupy a number of contiguous pages with no
481 * headers on any page after the first.
483 typedef struct MDB_page {
484 #define mp_pgno mp_p.p_pgno
485 #define mp_next mp_p.p_next
487 pgno_t p_pgno; /**< page number */
488 void * p_next; /**< for in-memory list of freed structs */
490 #define P_BRANCH 0x01 /**< branch page */
491 #define P_LEAF 0x02 /**< leaf page */
492 #define P_OVERFLOW 0x04 /**< overflow page */
493 #define P_META 0x08 /**< meta page */
494 #define P_DIRTY 0x10 /**< dirty page */
495 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
497 #define mp_lower mp_pb.pb.pb_lower
498 #define mp_upper mp_pb.pb.pb_upper
499 #define mp_pages mp_pb.pb_pages
502 indx_t pb_lower; /**< lower bound of free space */
503 indx_t pb_upper; /**< upper bound of free space */
505 uint32_t pb_pages; /**< number of overflow pages */
507 indx_t mp_ptrs[1]; /**< dynamic size */
510 /** Size of the page header, excluding dynamic data at the end */
511 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
513 /** Address of first usable data byte in a page, after the header */
514 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
516 /** Number of nodes on a page */
517 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
519 /** The amount of space remaining in the page */
520 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
522 /** The percentage of space used in the page, in tenths of a percent. */
523 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
524 ((env)->me_psize - PAGEHDRSZ))
525 /** The minimum page fill factor, in tenths of a percent.
526 * Pages emptier than this are candidates for merging.
528 #define FILL_THRESHOLD 250
530 /** Test if a page is a leaf page */
531 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
532 /** Test if a page is a LEAF2 page */
533 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
534 /** Test if a page is a branch page */
535 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
536 /** Test if a page is an overflow page */
537 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
539 /** The number of overflow pages needed to store the given size. */
540 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
542 /** Header for a single key/data pair within a page.
543 * We guarantee 2-byte alignment for nodes.
545 typedef struct MDB_node {
546 /** lo and hi are used for data size on leaf nodes and for
547 * child pgno on branch nodes. On 64 bit platforms, flags
548 * is also used for pgno. (Branch nodes have no flags).
549 * They are in in host byte order in case that lets some
550 * accesses be optimized into a 32-bit word access.
552 #define mn_lo mn_offset[__BYTE_ORDER!=__LITTLE_ENDIAN]
553 #define mn_hi mn_offset[__BYTE_ORDER==__LITTLE_ENDIAN] /**< part of dsize or pgno */
554 unsigned short mn_offset[2];
555 unsigned short mn_flags; /**< flags for special node types */
556 #define F_BIGDATA 0x01 /**< data put on overflow page */
557 #define F_SUBDATA 0x02 /**< data is a sub-database */
558 #define F_DUPDATA 0x04 /**< data has duplicates */
559 unsigned short mn_ksize; /**< key size */
560 char mn_data[1]; /**< key and data are appended here */
563 /** Size of the node header, excluding dynamic data at the end */
564 #define NODESIZE offsetof(MDB_node, mn_data)
566 /** Size of a node in a branch page with a given key.
567 * This is just the node header plus the key, there is no data.
569 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
571 /** Size of a node in a leaf page with a given key and data.
572 * This is node header plus key plus data size.
574 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
576 /** Address of node \b i in page \b p */
577 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
579 /** Address of the key for the node */
580 #define NODEKEY(node) (void *)((node)->mn_data)
582 /** Address of the data for a node */
583 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
585 /** Get the page number pointed to by a branch node */
586 #if LONG_MAX == 0x7fffffff
587 #define NODEPGNO(node) ((node)->mn_lo | ((node)->mn_hi << 16))
588 /** Set the page number in a branch node */
589 #define SETPGNO(node,pgno) do { \
590 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16;} while(0)
592 #define NODEPGNO(node) ((node)->mn_lo | ((node)->mn_hi << 16) | ((unsigned long)(node)->mn_flags << 32))
593 /** Set the page number in a branch node */
594 #define SETPGNO(node,pgno) do { \
595 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
596 (node)->mn_flags = (pgno) >> 32; } while(0)
599 /** Get the size of the data in a leaf node */
600 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
601 /** Set the size of the data for a leaf node */
602 #define SETDSZ(node,size) do { \
603 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
604 /** The size of a key in a node */
605 #define NODEKSZ(node) ((node)->mn_ksize)
607 /** The address of a key in a LEAF2 page.
608 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
609 * There are no node headers, keys are stored contiguously.
611 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
613 /** Set the \b node's key into \b key, if requested. */
614 #define MDB_SET_KEY(node, key) { if ((key) != NULL) { \
615 (key)->mv_size = NODEKSZ(node); (key)->mv_data = NODEKEY(node); } }
617 /** Information about a single database in the environment. */
618 typedef struct MDB_db {
619 uint32_t md_pad; /**< also ksize for LEAF2 pages */
620 uint16_t md_flags; /**< @ref mdb_open */
621 uint16_t md_depth; /**< depth of this tree */
622 ULONG md_branch_pages; /**< number of internal pages */
623 ULONG md_leaf_pages; /**< number of leaf pages */
624 ULONG md_overflow_pages; /**< number of overflow pages */
625 ULONG md_entries; /**< number of data items */
626 pgno_t md_root; /**< the root page of this tree */
629 /** Handle for the DB used to track free pages. */
631 /** Handle for the default DB. */
634 /** Meta page content. */
635 typedef struct MDB_meta {
636 /** Stamp identifying this as an MDB data file. It must be set
639 /** Version number of this lock file. Must be set to #MDB_VERSION. */
641 void *mm_address; /**< address for fixed mapping */
642 size_t mm_mapsize; /**< size of mmap region */
643 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
644 /** The size of pages used in this DB */
645 #define mm_psize mm_dbs[0].md_pad
646 /** Any persistent environment flags. @ref mdb_env */
647 #define mm_flags mm_dbs[0].md_flags
648 pgno_t mm_last_pg; /**< last used page in file */
649 txnid_t mm_txnid; /**< txnid that committed this page */
652 /** Auxiliary DB info.
653 * The information here is mostly static/read-only. There is
654 * only a single copy of this record in the environment.
655 * The \b md_dirty flag is not read-only, but only a write
656 * transaction can ever update it, and only write transactions
657 * need to worry about it.
659 typedef struct MDB_dbx {
660 MDB_val md_name; /**< name of the database */
661 MDB_cmp_func *md_cmp; /**< function for comparing keys */
662 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
663 MDB_rel_func *md_rel; /**< user relocate function */
664 MDB_dbi md_parent; /**< parent DB of a sub-DB */
665 unsigned int md_dirty; /**< TRUE if DB was written in this txn */
668 /** A database transaction.
669 * Every operation requires a transaction handle.
672 pgno_t mt_next_pgno; /**< next unallocated page */
673 /** The ID of this transaction. IDs are integers incrementing from 1.
674 * Only committed write transactions increment the ID. If a transaction
675 * aborts, the ID may be re-used by the next writer.
678 MDB_env *mt_env; /**< the DB environment */
679 /** The list of pages that became unused during this transaction.
684 ID2L dirty_list; /**< modified pages */
685 MDB_reader *reader; /**< this thread's slot in the reader table */
687 /** Array of records for each DB known in the environment. */
689 /** Array of MDB_db records for each known DB */
691 /** Number of DB records in use. This number only ever increments;
692 * we don't decrement it when individual DB handles are closed.
694 unsigned int mt_numdbs;
696 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
697 #define MDB_TXN_ERROR 0x02 /**< an error has occurred */
698 unsigned int mt_flags;
699 /** Tracks which of the two meta pages was used at the start
700 * of this transaction.
702 unsigned int mt_toggle;
705 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
706 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
707 * raise this on a 64 bit machine.
709 #define CURSOR_STACK 32
713 /** Cursors are used for all DB operations */
715 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
716 struct MDB_xcursor *mc_xcursor;
717 /** The transaction that owns this cursor */
719 /** The database handle this cursor operates on */
721 unsigned short mc_snum; /**< number of pushed pages */
722 unsigned short mc_top; /**< index of top page, mc_snum-1 */
723 unsigned int mc_flags;
724 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
725 #define C_EOF 0x02 /**< No more data */
726 #define C_XDIRTY 0x04 /**< @deprecated mc_xcursor needs to be flushed */
727 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
728 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
731 /** Context for sorted-dup records.
732 * We could have gone to a fully recursive design, with arbitrarily
733 * deep nesting of sub-databases. But for now we only handle these
734 * levels - main DB, optional sub-DB, sorted-duplicate DB.
736 typedef struct MDB_xcursor {
737 /** A sub-cursor for traversing the Dup DB */
738 MDB_cursor mx_cursor;
739 /** A fake transaction struct for pointing to our own table
743 /** Our private DB information tables. Slots 0 and 1 are always
744 * copies of the corresponding slots in the main transaction. These
745 * hold the FREEDB and MAINDB, respectively. If the main cursor is
746 * on a sub-database, that will be copied to slot 2, and the duplicate
747 * database info will be in slot 3. If the main cursor is on the MAINDB
748 * then the duplicate DB info will be in slot 2 and slot 3 will be unused.
755 /** A set of pages freed by an earlier transaction. */
756 typedef struct MDB_oldpages {
757 /** Usually we only read one record from the FREEDB at a time, but
758 * in case we read more, this will chain them together.
760 struct MDB_oldpages *mo_next;
761 /** The ID of the transaction in which these pages were freed. */
763 /** An #IDL of the pages */
764 pgno_t mo_pages[1]; /* dynamic */
767 /** The database environment. */
769 HANDLE me_fd; /**< The main data file */
770 HANDLE me_lfd; /**< The lock file */
771 HANDLE me_mfd; /**< just for writing the meta pages */
772 /** Failed to update the meta page. Probably an I/O error. */
773 #define MDB_FATAL_ERROR 0x80000000U
775 uint32_t me_extrapad; /**< unused for now */
776 unsigned int me_maxreaders; /**< size of the reader table */
777 unsigned int me_numdbs; /**< number of DBs opened */
778 unsigned int me_maxdbs; /**< size of the DB table */
779 char *me_path; /**< path to the DB files */
780 char *me_map; /**< the memory map of the data file */
781 MDB_txninfo *me_txns; /**< the memory map of the lock file */
782 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
783 MDB_txn *me_txn; /**< current write transaction */
784 size_t me_mapsize; /**< size of the data memory map */
785 off_t me_size; /**< current file size */
786 pgno_t me_maxpg; /**< me_mapsize / me_psize */
787 unsigned int me_psize; /**< size of a page, from #GET_PAGESIZE */
788 unsigned int me_db_toggle; /**< which DB table is current */
789 MDB_dbx *me_dbxs; /**< array of static DB info */
790 MDB_db *me_dbs[2]; /**< two arrays of MDB_db info */
791 MDB_oldpages *me_pghead; /**< list of old page records */
792 pthread_key_t me_txkey; /**< thread-key for readers */
793 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
794 /** IDL of pages that became unused in a write txn */
795 pgno_t me_free_pgs[MDB_IDL_UM_SIZE];
796 /** ID2L of pages that were written during a write txn */
797 ID2 me_dirty_list[MDB_IDL_UM_SIZE];
798 /** rwlock for the DB tables, if #LAZY_LOCKS is false */
799 LAZY_RWLOCK_DEF(me_dblock)
801 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
805 /** max number of pages to commit in one writev() call */
806 #define MDB_COMMIT_PAGES 64
808 static MDB_page *mdb_alloc_page(MDB_cursor *mc, int num);
809 static int mdb_touch(MDB_cursor *mc);
811 static int mdb_search_page_root(MDB_cursor *mc,
812 MDB_val *key, int modify);
813 static int mdb_search_page(MDB_cursor *mc,
814 MDB_val *key, int modify);
816 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
817 static int mdb_env_read_meta(MDB_env *env, int *which);
818 static int mdb_env_write_meta(MDB_txn *txn);
819 static int mdb_get_page(MDB_txn *txn, pgno_t pgno, MDB_page **mp);
821 static MDB_node *mdb_search_node(MDB_cursor *mc, MDB_val *key, int *exactp);
822 static int mdb_add_node(MDB_cursor *mc, indx_t indx,
823 MDB_val *key, MDB_val *data, pgno_t pgno, uint8_t flags);
824 static void mdb_del_node(MDB_page *mp, indx_t indx, int ksize);
825 static int mdb_del0(MDB_cursor *mc, MDB_node *leaf);
826 static int mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
828 static int mdb_rebalance(MDB_cursor *mc);
829 static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key);
830 static int mdb_move_node(MDB_cursor *csrc, MDB_cursor *cdst);
831 static int mdb_merge(MDB_cursor *csrc, MDB_cursor *cdst);
832 static int mdb_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
834 static MDB_page *mdb_new_page(MDB_cursor *mc, uint32_t flags, int num);
836 static void cursor_pop_page(MDB_cursor *mc);
837 static int cursor_push_page(MDB_cursor *mc, MDB_page *mp);
839 static int mdb_sibling(MDB_cursor *mc, int move_right);
840 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
841 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
842 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
844 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
845 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
847 static void mdb_xcursor_init0(MDB_cursor *mc);
848 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
849 static void mdb_xcursor_init2(MDB_cursor *mc);
850 static void mdb_xcursor_fini(MDB_cursor *mc);
852 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
853 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
855 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
858 static MDB_cmp_func memncmp, memnrcmp, intcmp, cintcmp;
862 static SECURITY_DESCRIPTOR mdb_null_sd;
863 static SECURITY_ATTRIBUTES mdb_all_sa;
864 static int mdb_sec_inited;
867 /** Return the library version info. */
869 mdb_version(int *major, int *minor, int *patch)
871 if (major) *major = MDB_VERSION_MAJOR;
872 if (minor) *minor = MDB_VERSION_MINOR;
873 if (patch) *patch = MDB_VERSION_PATCH;
874 return MDB_VERSION_STRING;
877 /** Table of descriptions for MDB @ref errors */
878 static char *const mdb_errstr[] = {
879 "MDB_KEYEXIST: Key/data pair already exists",
880 "MDB_NOTFOUND: No matching key/data pair found",
881 "MDB_PAGE_NOTFOUND: Requested page not found",
882 "MDB_CORRUPTED: Located page was wrong type",
883 "MDB_PANIC: Update of meta page failed",
884 "MDB_VERSION_MISMATCH: Database environment version mismatch"
888 mdb_strerror(int err)
891 return ("Successful return: 0");
893 if (err >= MDB_KEYEXIST && err <= MDB_VERSION_MISMATCH)
894 return mdb_errstr[err - MDB_KEYEXIST];
896 return strerror(err);
900 /** Display a key in hexadecimal and return the address of the result.
901 * @param[in] key the key to display
902 * @param[in] buf the buffer to write into. Should always be #DKBUF.
903 * @return The key in hexadecimal form.
906 mdb_dkey(MDB_val *key, char *buf)
909 unsigned char *c = key->mv_data;
911 if (key->mv_size > MAXKEYSIZE)
913 /* may want to make this a dynamic check: if the key is mostly
914 * printable characters, print it as-is instead of converting to hex.
917 for (i=0; i<key->mv_size; i++)
918 ptr += sprintf(ptr, "%02x", *c++);
920 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
927 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
929 return txn->mt_dbxs[dbi].md_cmp(a, b);
932 /** Compare two data items according to a particular database.
933 * This returns a comparison as if the two items were data items of
934 * a sorted duplicates #MDB_DUPSORT database.
935 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
936 * @param[in] dbi A database handle returned by #mdb_open()
937 * @param[in] a The first item to compare
938 * @param[in] b The second item to compare
939 * @return < 0 if a < b, 0 if a == b, > 0 if a > b
942 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
944 if (txn->mt_dbxs[dbi].md_dcmp)
945 return txn->mt_dbxs[dbi].md_dcmp(a, b);
947 return EINVAL; /* too bad you can't distinguish this from a valid result */
950 /** Allocate pages for writing.
951 * If there are free pages available from older transactions, they
952 * will be re-used first. Otherwise a new page will be allocated.
953 * @param[in] mc cursor A cursor handle identifying the transaction and
954 * database for which we are allocating.
955 * @param[in] num the number of pages to allocate.
956 * @return Address of the allocated page(s). Requests for multiple pages
957 * will always be satisfied by a single contiguous chunk of memory.
960 mdb_alloc_page(MDB_cursor *mc, int num)
962 MDB_txn *txn = mc->mc_txn;
964 pgno_t pgno = P_INVALID;
967 if (txn->mt_txnid > 2) {
969 if (!txn->mt_env->me_pghead && mc->mc_dbi != FREE_DBI &&
970 txn->mt_dbs[FREE_DBI].md_root != P_INVALID) {
971 /* See if there's anything in the free DB */
974 txnid_t *kptr, oldest;
977 m2.mc_dbi = FREE_DBI;
980 mdb_search_page(&m2, NULL, 0);
981 leaf = NODEPTR(m2.mc_pg[m2.mc_top], 0);
982 kptr = (txnid_t *)NODEKEY(leaf);
986 oldest = txn->mt_txnid - 1;
987 for (i=0; i<txn->mt_env->me_txns->mti_numreaders; i++) {
988 txnid_t mr = txn->mt_env->me_txns->mti_readers[i].mr_txnid;
989 if (mr && mr < oldest)
994 if (oldest > *kptr) {
995 /* It's usable, grab it.
1001 mdb_read_data(txn, leaf, &data);
1002 idl = (ULONG *)data.mv_data;
1003 mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t));
1004 mop->mo_next = txn->mt_env->me_pghead;
1005 mop->mo_txnid = *kptr;
1006 txn->mt_env->me_pghead = mop;
1007 memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl));
1012 DPRINTF("IDL read txn %lu root %lu num %lu",
1013 mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
1014 for (i=0; i<idl[0]; i++) {
1015 DPRINTF("IDL %lu", idl[i+1]);
1019 /* drop this IDL from the DB */
1020 m2.mc_ki[m2.mc_top] = 0;
1021 m2.mc_flags = C_INITIALIZED;
1022 mdb_cursor_del(&m2, 0);
1025 if (txn->mt_env->me_pghead) {
1026 MDB_oldpages *mop = txn->mt_env->me_pghead;
1028 /* FIXME: For now, always use fresh pages. We
1029 * really ought to search the free list for a
1034 /* peel pages off tail, so we only have to truncate the list */
1035 pgno = MDB_IDL_LAST(mop->mo_pages);
1036 if (MDB_IDL_IS_RANGE(mop->mo_pages)) {
1038 if (mop->mo_pages[2] > mop->mo_pages[1])
1039 mop->mo_pages[0] = 0;
1043 if (MDB_IDL_IS_ZERO(mop->mo_pages)) {
1044 txn->mt_env->me_pghead = mop->mo_next;
1051 if (pgno == P_INVALID) {
1052 /* DB size is maxed out */
1053 if (txn->mt_next_pgno + num >= txn->mt_env->me_maxpg)
1056 if (txn->mt_env->me_dpages && num == 1) {
1057 np = txn->mt_env->me_dpages;
1058 txn->mt_env->me_dpages = np->mp_next;
1060 if ((np = malloc(txn->mt_env->me_psize * num )) == NULL)
1063 if (pgno == P_INVALID) {
1064 np->mp_pgno = txn->mt_next_pgno;
1065 txn->mt_next_pgno += num;
1069 mid.mid = np->mp_pgno;
1071 mdb_mid2l_insert(txn->mt_u.dirty_list, &mid);
1076 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
1077 * @param[in] mc cursor pointing to the page to be touched
1078 * @return 0 on success, non-zero on failure.
1081 mdb_touch(MDB_cursor *mc)
1083 MDB_page *mp = mc->mc_pg[mc->mc_top];
1086 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
1088 if ((np = mdb_alloc_page(mc, 1)) == NULL)
1090 DPRINTF("touched db %u page %lu -> %lu", mc->mc_dbi, mp->mp_pgno, np->mp_pgno);
1091 assert(mp->mp_pgno != np->mp_pgno);
1092 mdb_midl_append(mc->mc_txn->mt_free_pgs, mp->mp_pgno);
1094 memcpy(np, mp, mc->mc_txn->mt_env->me_psize);
1097 mp->mp_flags |= P_DIRTY;
1099 mc->mc_pg[mc->mc_top] = mp;
1100 /** If this page has a parent, update the parent to point to
1104 SETPGNO(NODEPTR(mc->mc_pg[mc->mc_top-1], mc->mc_ki[mc->mc_top-1]), mp->mp_pgno);
1110 mdb_env_sync(MDB_env *env, int force)
1113 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
1114 if (fdatasync(env->me_fd))
1121 mdb_txn_reset0(MDB_txn *txn);
1123 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
1124 * @param[in] txn the transaction handle to initialize
1125 * @return 0 on success, non-zero on failure. This can only
1126 * fail for read-only transactions, and then only if the
1127 * reader table is full.
1130 mdb_txn_renew0(MDB_txn *txn)
1132 MDB_env *env = txn->mt_env;
1134 if (txn->mt_flags & MDB_TXN_RDONLY) {
1135 MDB_reader *r = pthread_getspecific(env->me_txkey);
1138 pid_t pid = getpid();
1139 pthread_t tid = pthread_self();
1142 for (i=0; i<env->me_txns->mti_numreaders; i++)
1143 if (env->me_txns->mti_readers[i].mr_pid == 0)
1145 if (i == env->me_maxreaders) {
1146 UNLOCK_MUTEX_R(env);
1149 env->me_txns->mti_readers[i].mr_pid = pid;
1150 env->me_txns->mti_readers[i].mr_tid = tid;
1151 if (i >= env->me_txns->mti_numreaders)
1152 env->me_txns->mti_numreaders = i+1;
1153 UNLOCK_MUTEX_R(env);
1154 r = &env->me_txns->mti_readers[i];
1155 pthread_setspecific(env->me_txkey, r);
1157 txn->mt_txnid = env->me_txns->mti_txnid;
1158 txn->mt_toggle = env->me_txns->mti_me_toggle;
1159 r->mr_txnid = txn->mt_txnid;
1160 txn->mt_u.reader = r;
1164 txn->mt_txnid = env->me_txns->mti_txnid+1;
1165 txn->mt_toggle = env->me_txns->mti_me_toggle;
1166 txn->mt_u.dirty_list = env->me_dirty_list;
1167 txn->mt_u.dirty_list[0].mid = 0;
1168 txn->mt_free_pgs = env->me_free_pgs;
1169 txn->mt_free_pgs[0] = 0;
1170 txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
1174 /* Copy the DB arrays */
1175 LAZY_RWLOCK_RDLOCK(&env->me_dblock);
1176 txn->mt_numdbs = env->me_numdbs;
1177 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
1178 memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db));
1179 if (txn->mt_numdbs > 2)
1180 memcpy(txn->mt_dbs+2, env->me_dbs[env->me_db_toggle]+2,
1181 (txn->mt_numdbs - 2) * sizeof(MDB_db));
1182 LAZY_RWLOCK_UNLOCK(&env->me_dblock);
1188 mdb_txn_renew(MDB_txn *txn)
1195 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
1196 DPUTS("environment had fatal error, must shutdown!");
1200 rc = mdb_txn_renew0(txn);
1201 if (rc == MDB_SUCCESS) {
1202 DPRINTF("renew txn %lu%c %p on mdbenv %p, root page %lu",
1203 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
1204 (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1210 mdb_txn_begin(MDB_env *env, unsigned int flags, MDB_txn **ret)
1215 if (env->me_flags & MDB_FATAL_ERROR) {
1216 DPUTS("environment had fatal error, must shutdown!");
1219 if ((txn = calloc(1, sizeof(MDB_txn) + env->me_maxdbs * sizeof(MDB_db))) == NULL) {
1220 DPRINTF("calloc: %s", strerror(ErrCode()));
1223 txn->mt_dbs = (MDB_db *)(txn+1);
1224 if (flags & MDB_RDONLY) {
1225 txn->mt_flags |= MDB_TXN_RDONLY;
1229 rc = mdb_txn_renew0(txn);
1234 DPRINTF("begin txn %lu%c %p on mdbenv %p, root page %lu",
1235 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
1236 (void *) env, txn->mt_dbs[MAIN_DBI].md_root);
1242 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
1243 * @param[in] txn the transaction handle to reset
1246 mdb_txn_reset0(MDB_txn *txn)
1248 MDB_env *env = txn->mt_env;
1250 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
1251 txn->mt_u.reader->mr_txnid = 0;
1257 /* return all dirty pages to dpage list */
1258 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
1259 dp = txn->mt_u.dirty_list[i].mptr;
1260 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1261 dp->mp_next = txn->mt_env->me_dpages;
1262 txn->mt_env->me_dpages = dp;
1264 /* large pages just get freed directly */
1269 while ((mop = txn->mt_env->me_pghead)) {
1270 txn->mt_env->me_pghead = mop->mo_next;
1275 for (i=2; i<env->me_numdbs; i++)
1276 env->me_dbxs[i].md_dirty = 0;
1277 /* The writer mutex was locked in mdb_txn_begin. */
1278 UNLOCK_MUTEX_W(env);
1283 mdb_txn_reset(MDB_txn *txn)
1288 DPRINTF("reset txn %lu%c %p on mdbenv %p, root page %lu",
1289 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
1290 (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1292 mdb_txn_reset0(txn);
1296 mdb_txn_abort(MDB_txn *txn)
1301 DPRINTF("abort txn %lu%c %p on mdbenv %p, root page %lu",
1302 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', txn,
1303 (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root);
1305 mdb_txn_reset0(txn);
1310 mdb_txn_commit(MDB_txn *txn)
1321 assert(txn != NULL);
1322 assert(txn->mt_env != NULL);
1326 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
1331 if (txn != env->me_txn) {
1332 DPUTS("attempt to commit unknown transaction");
1337 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
1338 DPUTS("error flag is set, can't commit");
1343 if (!txn->mt_u.dirty_list[0].mid)
1346 DPRINTF("committing txn %lu %p on mdbenv %p, root page %lu",
1347 txn->mt_txnid, txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root);
1350 mc.mc_dbi = FREE_DBI;
1353 /* should only be one record now */
1354 if (env->me_pghead) {
1355 /* make sure first page of freeDB is touched and on freelist */
1356 mdb_search_page(&mc, NULL, 1);
1358 /* save to free list */
1359 if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) {
1363 /* make sure last page of freeDB is touched and on freelist */
1364 key.mv_size = MAXKEYSIZE+1;
1366 mdb_search_page(&mc, &key, 1);
1368 mdb_midl_sort(txn->mt_free_pgs);
1372 ULONG *idl = txn->mt_free_pgs;
1373 DPRINTF("IDL write txn %lu root %lu num %lu",
1374 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]);
1375 for (i=0; i<idl[0]; i++) {
1376 DPRINTF("IDL %lu", idl[i+1]);
1380 /* write to last page of freeDB */
1381 key.mv_size = sizeof(pgno_t);
1382 key.mv_data = &txn->mt_txnid;
1383 data.mv_data = txn->mt_free_pgs;
1384 /* The free list can still grow during this call,
1385 * despite the pre-emptive touches above. So check
1386 * and make sure the entire thing got written.
1389 i = txn->mt_free_pgs[0];
1390 data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs);
1391 rc = mdb_cursor_put(&mc, &key, &data, 0);
1396 } while (i != txn->mt_free_pgs[0]);
1398 /* should only be one record now */
1399 if (env->me_pghead) {
1403 mop = env->me_pghead;
1404 key.mv_size = sizeof(pgno_t);
1405 key.mv_data = &mop->mo_txnid;
1406 data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages);
1407 data.mv_data = mop->mo_pages;
1408 mdb_cursor_put(&mc, &key, &data, 0);
1409 free(env->me_pghead);
1410 env->me_pghead = NULL;
1413 /* Update DB root pointers. Their pages have already been
1414 * touched so this is all in-place and cannot fail.
1418 data.mv_size = sizeof(MDB_db);
1420 mc.mc_dbi = MAIN_DBI;
1422 for (i = 2; i < txn->mt_numdbs; i++) {
1423 if (txn->mt_dbxs[i].md_dirty) {
1424 data.mv_data = &txn->mt_dbs[i];
1425 mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
1430 /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
1436 /* Windows actually supports scatter/gather I/O, but only on
1437 * unbuffered file handles. Since we're relying on the OS page
1438 * cache for all our data, that's self-defeating. So we just
1439 * write pages one at a time. We use the ov structure to set
1440 * the write offset, to at least save the overhead of a Seek
1444 memset(&ov, 0, sizeof(ov));
1445 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
1447 dp = txn->mt_u.dirty_list[i].mptr;
1448 DPRINTF("committing page %lu", dp->mp_pgno);
1449 size = dp->mp_pgno * env->me_psize;
1450 ov.Offset = size & 0xffffffff;
1451 ov.OffsetHigh = size >> 16;
1452 ov.OffsetHigh >>= 16;
1453 /* clear dirty flag */
1454 dp->mp_flags &= ~P_DIRTY;
1455 wsize = env->me_psize;
1456 if (IS_OVERFLOW(dp)) wsize *= dp->mp_pages;
1457 rc = WriteFile(env->me_fd, dp, wsize, NULL, &ov);
1460 DPRINTF("WriteFile: %d", n);
1467 struct iovec iov[MDB_COMMIT_PAGES];
1471 for (; i<=txn->mt_u.dirty_list[0].mid; i++) {
1472 dp = txn->mt_u.dirty_list[i].mptr;
1473 if (dp->mp_pgno != next) {
1475 DPRINTF("committing %u dirty pages", n);
1476 rc = writev(env->me_fd, iov, n);
1480 DPUTS("short write, filesystem full?");
1482 DPRINTF("writev: %s", strerror(n));
1489 lseek(env->me_fd, dp->mp_pgno * env->me_psize, SEEK_SET);
1492 DPRINTF("committing page %lu", dp->mp_pgno);
1493 iov[n].iov_len = env->me_psize;
1494 if (IS_OVERFLOW(dp)) iov[n].iov_len *= dp->mp_pages;
1495 iov[n].iov_base = dp;
1496 size += iov[n].iov_len;
1497 next = dp->mp_pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1);
1498 /* clear dirty flag */
1499 dp->mp_flags &= ~P_DIRTY;
1500 if (++n >= MDB_COMMIT_PAGES) {
1510 DPRINTF("committing %u dirty pages", n);
1511 rc = writev(env->me_fd, iov, n);
1515 DPUTS("short write, filesystem full?");
1517 DPRINTF("writev: %s", strerror(n));
1524 /* Drop the dirty pages.
1526 for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
1527 dp = txn->mt_u.dirty_list[i].mptr;
1528 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1529 dp->mp_next = txn->mt_env->me_dpages;
1530 txn->mt_env->me_dpages = dp;
1534 txn->mt_u.dirty_list[i].mid = 0;
1536 txn->mt_u.dirty_list[0].mid = 0;
1538 if ((n = mdb_env_sync(env, 0)) != 0 ||
1539 (n = mdb_env_write_meta(txn)) != MDB_SUCCESS) {
1546 /* update the DB tables */
1548 int toggle = !env->me_db_toggle;
1551 ip = &env->me_dbs[toggle][2];
1552 jp = &txn->mt_dbs[2];
1553 LAZY_RWLOCK_WRLOCK(&env->me_dblock);
1554 for (i = 2; i < txn->mt_numdbs; i++) {
1555 if (ip->md_root != jp->md_root)
1560 for (i = 2; i < txn->mt_numdbs; i++) {
1561 if (txn->mt_dbxs[i].md_dirty)
1562 txn->mt_dbxs[i].md_dirty = 0;
1564 env->me_db_toggle = toggle;
1565 env->me_numdbs = txn->mt_numdbs;
1566 LAZY_RWLOCK_UNLOCK(&env->me_dblock);
1569 UNLOCK_MUTEX_W(env);
1575 /** Read the environment parameters of a DB environment before
1576 * mapping it into memory.
1577 * @param[in] env the environment handle
1578 * @param[out] meta address of where to store the meta information
1579 * @return 0 on success, non-zero on failure.
1582 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
1584 char page[PAGESIZE];
1589 /* We don't know the page size yet, so use a minimum value.
1593 if (!ReadFile(env->me_fd, page, PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
1595 if ((rc = read(env->me_fd, page, PAGESIZE)) == 0)
1600 else if (rc != PAGESIZE) {
1604 DPRINTF("read: %s", strerror(err));
1608 p = (MDB_page *)page;
1610 if (!F_ISSET(p->mp_flags, P_META)) {
1611 DPRINTF("page %lu not a meta page", p->mp_pgno);
1616 if (m->mm_magic != MDB_MAGIC) {
1617 DPUTS("meta has invalid magic");
1621 if (m->mm_version != MDB_VERSION) {
1622 DPRINTF("database is version %u, expected version %u",
1623 m->mm_version, MDB_VERSION);
1624 return MDB_VERSION_MISMATCH;
1627 memcpy(meta, m, sizeof(*m));
1631 /** Write the environment parameters of a freshly created DB environment.
1632 * @param[in] env the environment handle
1633 * @param[out] meta address of where to store the meta information
1634 * @return 0 on success, non-zero on failure.
1637 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
1644 DPUTS("writing new meta page");
1646 GET_PAGESIZE(psize);
1648 meta->mm_magic = MDB_MAGIC;
1649 meta->mm_version = MDB_VERSION;
1650 meta->mm_psize = psize;
1651 meta->mm_last_pg = 1;
1652 meta->mm_flags = env->me_flags & 0xffff;
1653 meta->mm_flags |= MDB_INTEGERKEY;
1654 meta->mm_dbs[0].md_root = P_INVALID;
1655 meta->mm_dbs[1].md_root = P_INVALID;
1657 p = calloc(2, psize);
1659 p->mp_flags = P_META;
1662 memcpy(m, meta, sizeof(*meta));
1664 q = (MDB_page *)((char *)p + psize);
1667 q->mp_flags = P_META;
1670 memcpy(m, meta, sizeof(*meta));
1675 rc = WriteFile(env->me_fd, p, psize * 2, &len, NULL);
1676 rc = (len == psize * 2) ? MDB_SUCCESS : ErrCode();
1679 rc = write(env->me_fd, p, psize * 2);
1680 rc = (rc == (int)psize * 2) ? MDB_SUCCESS : ErrCode();
1686 /** Update the environment info to commit a transaction.
1687 * @param[in] txn the transaction that's being committed
1688 * @return 0 on success, non-zero on failure.
1691 mdb_env_write_meta(MDB_txn *txn)
1694 MDB_meta meta, metab;
1696 int rc, len, toggle;
1702 assert(txn != NULL);
1703 assert(txn->mt_env != NULL);
1705 toggle = !txn->mt_toggle;
1706 DPRINTF("writing meta page %d for root page %lu",
1707 toggle, txn->mt_dbs[MAIN_DBI].md_root);
1711 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
1712 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
1714 ptr = (char *)&meta;
1715 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
1716 len = sizeof(MDB_meta) - off;
1719 meta.mm_dbs[0] = txn->mt_dbs[0];
1720 meta.mm_dbs[1] = txn->mt_dbs[1];
1721 meta.mm_last_pg = txn->mt_next_pgno - 1;
1722 meta.mm_txnid = txn->mt_txnid;
1725 off += env->me_psize;
1728 /* Write to the SYNC fd */
1731 memset(&ov, 0, sizeof(ov));
1733 WriteFile(env->me_mfd, ptr, len, (DWORD *)&rc, &ov);
1736 rc = pwrite(env->me_mfd, ptr, len, off);
1741 DPUTS("write failed, disk error?");
1742 /* On a failure, the pagecache still contains the new data.
1743 * Write some old data back, to prevent it from being used.
1744 * Use the non-SYNC fd; we know it will fail anyway.
1746 meta.mm_last_pg = metab.mm_last_pg;
1747 meta.mm_txnid = metab.mm_txnid;
1749 WriteFile(env->me_fd, ptr, len, NULL, &ov);
1751 r2 = pwrite(env->me_fd, ptr, len, off);
1753 env->me_flags |= MDB_FATAL_ERROR;
1756 /* Memory ordering issues are irrelevant; since the entire writer
1757 * is wrapped by wmutex, all of these changes will become visible
1758 * after the wmutex is unlocked. Since the DB is multi-version,
1759 * readers will get consistent data regardless of how fresh or
1760 * how stale their view of these values is.
1762 LAZY_MUTEX_LOCK(&env->me_txns->mti_mutex);
1763 txn->mt_env->me_txns->mti_me_toggle = toggle;
1764 txn->mt_env->me_txns->mti_txnid = txn->mt_txnid;
1765 LAZY_MUTEX_UNLOCK(&env->me_txns->mti_mutex);
1770 /** Check both meta pages to see which one is newer.
1771 * @param[in] env the environment handle
1772 * @param[out] which address of where to store the meta toggle ID
1773 * @return 0 on success, non-zero on failure.
1776 mdb_env_read_meta(MDB_env *env, int *which)
1780 assert(env != NULL);
1782 if (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid)
1785 DPRINTF("Using meta page %d", toggle);
1792 mdb_env_create(MDB_env **env)
1796 e = calloc(1, sizeof(MDB_env));
1797 if (!e) return ENOMEM;
1799 e->me_maxreaders = DEFAULT_READERS;
1801 e->me_fd = INVALID_HANDLE_VALUE;
1802 e->me_lfd = INVALID_HANDLE_VALUE;
1803 e->me_mfd = INVALID_HANDLE_VALUE;
1809 mdb_env_set_mapsize(MDB_env *env, size_t size)
1813 env->me_mapsize = size;
1818 mdb_env_set_maxdbs(MDB_env *env, int dbs)
1822 env->me_maxdbs = dbs;
1827 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
1829 if (env->me_map || readers < 1)
1831 env->me_maxreaders = readers;
1836 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
1838 if (!env || !readers)
1840 *readers = env->me_maxreaders;
1844 /** Further setup required for opening an MDB environment
1847 mdb_env_open2(MDB_env *env, unsigned int flags)
1849 int i, newenv = 0, toggle;
1853 env->me_flags = flags;
1855 memset(&meta, 0, sizeof(meta));
1857 if ((i = mdb_env_read_header(env, &meta)) != 0) {
1860 DPUTS("new mdbenv");
1864 if (!env->me_mapsize) {
1865 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
1871 LONG sizelo, sizehi;
1872 sizelo = env->me_mapsize & 0xffffffff;
1873 sizehi = env->me_mapsize >> 16; /* pointless on WIN32, only needed on W64 */
1875 /* Windows won't create mappings for zero length files.
1876 * Just allocate the maxsize right now.
1879 SetFilePointer(env->me_fd, sizelo, sizehi ? &sizehi : NULL, 0);
1880 if (!SetEndOfFile(env->me_fd))
1882 SetFilePointer(env->me_fd, 0, NULL, 0);
1884 mh = CreateFileMapping(env->me_fd, NULL, PAGE_READONLY,
1885 sizehi, sizelo, NULL);
1888 env->me_map = MapViewOfFileEx(mh, FILE_MAP_READ, 0, 0, env->me_mapsize,
1896 if (meta.mm_address && (flags & MDB_FIXEDMAP))
1898 env->me_map = mmap(meta.mm_address, env->me_mapsize, PROT_READ, i,
1900 if (env->me_map == MAP_FAILED)
1905 meta.mm_mapsize = env->me_mapsize;
1906 if (flags & MDB_FIXEDMAP)
1907 meta.mm_address = env->me_map;
1908 i = mdb_env_init_meta(env, &meta);
1909 if (i != MDB_SUCCESS) {
1910 munmap(env->me_map, env->me_mapsize);
1914 env->me_psize = meta.mm_psize;
1916 env->me_maxpg = env->me_mapsize / env->me_psize;
1918 p = (MDB_page *)env->me_map;
1919 env->me_metas[0] = METADATA(p);
1920 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize);
1922 if ((i = mdb_env_read_meta(env, &toggle)) != 0)
1925 DPRINTF("opened database version %u, pagesize %u",
1926 env->me_metas[toggle]->mm_version, env->me_psize);
1927 DPRINTF("depth: %u", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_depth);
1928 DPRINTF("entries: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_entries);
1929 DPRINTF("branch pages: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_branch_pages);
1930 DPRINTF("leaf pages: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_leaf_pages);
1931 DPRINTF("overflow pages: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_overflow_pages);
1932 DPRINTF("root: %lu", env->me_metas[toggle]->mm_dbs[MAIN_DBI].md_root);
1938 /* Windows doesn't support destructor callbacks for thread-specific storage */
1940 mdb_env_reader_dest(void *ptr)
1942 MDB_reader *reader = ptr;
1944 reader->mr_txnid = 0;
1950 /* downgrade the exclusive lock on the region back to shared */
1952 mdb_env_share_locks(MDB_env *env)
1956 if (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid)
1958 env->me_txns->mti_me_toggle = toggle;
1959 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
1964 /* First acquire a shared lock. The Unlock will
1965 * then release the existing exclusive lock.
1967 memset(&ov, 0, sizeof(ov));
1968 LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov);
1969 UnlockFile(env->me_lfd, 0, 0, 1, 0);
1973 struct flock lock_info;
1974 /* The shared lock replaces the existing lock */
1975 memset((void *)&lock_info, 0, sizeof(lock_info));
1976 lock_info.l_type = F_RDLCK;
1977 lock_info.l_whence = SEEK_SET;
1978 lock_info.l_start = 0;
1979 lock_info.l_len = 1;
1980 fcntl(env->me_lfd, F_SETLK, &lock_info);
1986 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
1994 if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
1995 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
1996 FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) {
2000 /* Try to get exclusive lock. If we succeed, then
2001 * nobody is using the lock region and we should initialize it.
2004 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
2008 memset(&ov, 0, sizeof(ov));
2009 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
2015 size = GetFileSize(env->me_lfd, NULL);
2017 if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
2021 /* Try to get exclusive lock. If we succeed, then
2022 * nobody is using the lock region and we should initialize it.
2025 struct flock lock_info;
2026 memset((void *)&lock_info, 0, sizeof(lock_info));
2027 lock_info.l_type = F_WRLCK;
2028 lock_info.l_whence = SEEK_SET;
2029 lock_info.l_start = 0;
2030 lock_info.l_len = 1;
2031 rc = fcntl(env->me_lfd, F_SETLK, &lock_info);
2035 lock_info.l_type = F_RDLCK;
2036 rc = fcntl(env->me_lfd, F_SETLKW, &lock_info);
2043 size = lseek(env->me_lfd, 0, SEEK_END);
2045 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
2046 if (size < rsize && *excl) {
2048 SetFilePointer(env->me_lfd, rsize, NULL, 0);
2049 if (!SetEndOfFile(env->me_lfd)) {
2054 if (ftruncate(env->me_lfd, rsize) != 0) {
2061 size = rsize - sizeof(MDB_txninfo);
2062 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
2067 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
2073 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
2075 if (!env->me_txns) {
2081 env->me_txns = mmap(0, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
2083 if (env->me_txns == MAP_FAILED) {
2091 if (!mdb_sec_inited) {
2092 InitializeSecurityDescriptor(&mdb_null_sd,
2093 SECURITY_DESCRIPTOR_REVISION);
2094 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
2095 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
2096 mdb_all_sa.bInheritHandle = FALSE;
2097 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
2100 /* FIXME: only using up to 20 characters of the env path here,
2101 * probably not enough to assure uniqueness...
2103 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%.20s", lpath);
2104 ptr = env->me_txns->mti_rmname + sizeof("Global\\MDBr");
2105 while ((ptr = strchr(ptr, '\\')))
2107 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
2108 if (!env->me_rmutex) {
2112 sprintf(env->me_txns->mti_rmname, "Global\\MDBw%.20s", lpath);
2113 ptr = env->me_txns->mti_rmname + sizeof("Global\\MDBw");
2114 while ((ptr = strchr(ptr, '\\')))
2116 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
2117 if (!env->me_wmutex) {
2122 pthread_mutexattr_t mattr;
2124 pthread_mutexattr_init(&mattr);
2125 rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
2129 pthread_mutex_init(&env->me_txns->mti_mutex, &mattr);
2130 pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr);
2132 env->me_txns->mti_version = MDB_VERSION;
2133 env->me_txns->mti_magic = MDB_MAGIC;
2134 env->me_txns->mti_txnid = 0;
2135 env->me_txns->mti_numreaders = 0;
2136 env->me_txns->mti_me_toggle = 0;
2139 if (env->me_txns->mti_magic != MDB_MAGIC) {
2140 DPUTS("lock region has invalid magic");
2144 if (env->me_txns->mti_version != MDB_VERSION) {
2145 DPRINTF("lock region is version %u, expected version %u",
2146 env->me_txns->mti_version, MDB_VERSION);
2147 rc = MDB_VERSION_MISMATCH;
2151 if (rc != EACCES && rc != EAGAIN) {
2155 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
2156 if (!env->me_rmutex) {
2160 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
2161 if (!env->me_wmutex) {
2171 env->me_lfd = INVALID_HANDLE_VALUE;
2176 /** The name of the lock file in the DB environment */
2177 #define LOCKNAME "/lock.mdb"
2178 /** The name of the data file in the DB environment */
2179 #define DATANAME "/data.mdb"
2181 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
2183 int oflags, rc, len, excl;
2184 char *lpath, *dpath;
2187 lpath = malloc(len + sizeof(LOCKNAME) + len + sizeof(DATANAME));
2190 dpath = lpath + len + sizeof(LOCKNAME);
2191 sprintf(lpath, "%s" LOCKNAME, path);
2192 sprintf(dpath, "%s" DATANAME, path);
2194 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
2199 if (F_ISSET(flags, MDB_RDONLY)) {
2200 oflags = GENERIC_READ;
2201 len = OPEN_EXISTING;
2203 oflags = GENERIC_READ|GENERIC_WRITE;
2206 mode = FILE_ATTRIBUTE_NORMAL;
2207 if ((env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
2208 NULL, len, mode, NULL)) == INVALID_HANDLE_VALUE) {
2213 if (F_ISSET(flags, MDB_RDONLY))
2216 oflags = O_RDWR | O_CREAT;
2218 if ((env->me_fd = open(dpath, oflags, mode)) == -1) {
2224 if ((rc = mdb_env_open2(env, flags)) == MDB_SUCCESS) {
2225 /* synchronous fd for meta writes */
2227 if (!(flags & (MDB_RDONLY|MDB_NOSYNC)))
2228 mode |= FILE_FLAG_WRITE_THROUGH;
2229 if ((env->me_mfd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
2230 NULL, len, mode, NULL)) == INVALID_HANDLE_VALUE) {
2235 if (!(flags & (MDB_RDONLY|MDB_NOSYNC)))
2236 oflags |= MDB_DSYNC;
2237 if ((env->me_mfd = open(dpath, oflags, mode)) == -1) {
2242 env->me_path = strdup(path);
2243 DPRINTF("opened dbenv %p", (void *) env);
2244 pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
2245 LAZY_RWLOCK_INIT(&env->me_dblock, NULL);
2247 mdb_env_share_locks(env);
2248 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
2249 env->me_dbs[0] = calloc(env->me_maxdbs, sizeof(MDB_db));
2250 env->me_dbs[1] = calloc(env->me_maxdbs, sizeof(MDB_db));
2256 if (env->me_fd != INVALID_HANDLE_VALUE) {
2258 env->me_fd = INVALID_HANDLE_VALUE;
2260 if (env->me_lfd != INVALID_HANDLE_VALUE) {
2262 env->me_lfd = INVALID_HANDLE_VALUE;
2270 mdb_env_close(MDB_env *env)
2277 while (env->me_dpages) {
2278 dp = env->me_dpages;
2279 env->me_dpages = dp->mp_next;
2283 free(env->me_dbs[1]);
2284 free(env->me_dbs[0]);
2288 LAZY_RWLOCK_DESTROY(&env->me_dblock);
2289 pthread_key_delete(env->me_txkey);
2292 munmap(env->me_map, env->me_mapsize);
2297 pid_t pid = getpid();
2299 for (i=0; i<env->me_txns->mti_numreaders; i++)
2300 if (env->me_txns->mti_readers[i].mr_pid == pid)
2301 env->me_txns->mti_readers[i].mr_pid = 0;
2302 munmap(env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
2308 /* only for aligned ints */
2310 intcmp(const MDB_val *a, const MDB_val *b)
2312 if (a->mv_size == sizeof(long))
2314 unsigned long *la, *lb;
2319 unsigned int *ia, *ib;
2326 /* ints must always be the same size */
2328 cintcmp(const MDB_val *a, const MDB_val *b)
2330 #if __BYTE_ORDER == __LITTLE_ENDIAN
2331 unsigned short *u, *c;
2334 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
2335 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
2338 } while(!x && u > (unsigned short *)a->mv_data);
2341 return memcmp(a->mv_data, b->mv_data, a->mv_size);
2346 memncmp(const MDB_val *a, const MDB_val *b)
2353 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
2359 diff = memcmp(a->mv_data, b->mv_data, len);
2360 return diff ? diff : len_diff<0 ? -1 : len_diff;
2364 memnrcmp(const MDB_val *a, const MDB_val *b)
2366 const unsigned char *p1, *p2, *p1_lim;
2370 p1_lim = (const unsigned char *)a->mv_data;
2371 p1 = (const unsigned char *)a->mv_data + a->mv_size;
2372 p2 = (const unsigned char *)b->mv_data + b->mv_size;
2374 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
2380 while (p1 > p1_lim) {
2381 diff = *--p1 - *--p2;
2385 return len_diff<0 ? -1 : len_diff;
2388 /* Search for key within a leaf page, using binary search.
2389 * Returns the smallest entry larger or equal to the key.
2390 * If exactp is non-null, stores whether the found entry was an exact match
2391 * in *exactp (1 or 0).
2392 * If kip is non-null, stores the index of the found entry in *kip.
2393 * If no entry larger or equal to the key is found, returns NULL.
2396 mdb_search_node(MDB_cursor *mc, MDB_val *key, int *exactp)
2398 unsigned int i = 0, nkeys;
2401 MDB_page *mp = mc->mc_pg[mc->mc_top];
2402 MDB_node *node = NULL;
2407 nkeys = NUMKEYS(mp);
2409 DPRINTF("searching %u keys in %s page %lu",
2410 nkeys, IS_LEAF(mp) ? "leaf" : "branch",
2415 low = IS_LEAF(mp) ? 0 : 1;
2417 cmp = mc->mc_txn->mt_dbxs[mc->mc_dbi].md_cmp;
2419 nodekey.mv_size = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
2420 node = NODEPTR(mp, 0); /* fake */
2422 while (low <= high) {
2423 i = (low + high) >> 1;
2426 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
2428 node = NODEPTR(mp, i);
2430 nodekey.mv_size = node->mn_ksize;
2431 nodekey.mv_data = NODEKEY(node);
2434 rc = cmp(key, &nodekey);
2438 DPRINTF("found leaf index %u [%s], rc = %i",
2439 i, DKEY(&nodekey), rc);
2441 DPRINTF("found branch index %u [%s -> %lu], rc = %i",
2442 i, DKEY(&nodekey), NODEPGNO(node), rc);
2453 if (rc > 0) { /* Found entry is less than the key. */
2454 i++; /* Skip to get the smallest entry larger than key. */
2456 node = NODEPTR(mp, i);
2459 *exactp = (rc == 0);
2460 /* store the key index */
2461 mc->mc_ki[mc->mc_top] = i;
2463 /* There is no entry larger or equal to the key. */
2466 /* nodeptr is fake for LEAF2 */
2471 cursor_pop_page(MDB_cursor *mc)
2476 top = mc->mc_pg[mc->mc_top];
2481 DPRINTF("popped page %lu off db %u cursor %p", top->mp_pgno,
2482 mc->mc_dbi, (void *) mc);
2487 cursor_push_page(MDB_cursor *mc, MDB_page *mp)
2489 DPRINTF("pushing page %lu on db %u cursor %p", mp->mp_pgno,
2490 mc->mc_dbi, (void *) mc);
2492 if (mc->mc_snum >= CURSOR_STACK)
2495 mc->mc_top = mc->mc_snum++;
2496 mc->mc_pg[mc->mc_top] = mp;
2497 mc->mc_ki[mc->mc_top] = 0;
2503 mdb_get_page(MDB_txn *txn, pgno_t pgno, MDB_page **ret)
2507 if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) {
2509 x = mdb_mid2l_search(txn->mt_u.dirty_list, pgno);
2510 if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) {
2511 p = txn->mt_u.dirty_list[x].mptr;
2515 if (pgno <= txn->mt_env->me_metas[txn->mt_toggle]->mm_last_pg)
2516 p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
2520 DPRINTF("page %lu not found", pgno);
2523 return (p != NULL) ? MDB_SUCCESS : MDB_PAGE_NOTFOUND;
2527 mdb_search_page_root(MDB_cursor *mc, MDB_val *key, int modify)
2529 MDB_page *mp = mc->mc_pg[mc->mc_top];
2534 while (IS_BRANCH(mp)) {
2537 DPRINTF("branch page %lu has %u keys", mp->mp_pgno, NUMKEYS(mp));
2538 assert(NUMKEYS(mp) > 1);
2539 DPRINTF("found index 0 to page %lu", NODEPGNO(NODEPTR(mp, 0)));
2541 if (key == NULL) /* Initialize cursor to first page. */
2542 mc->mc_ki[mc->mc_top] = 0;
2543 else if (key->mv_size > MAXKEYSIZE && key->mv_data == NULL) {
2544 /* cursor to last page */
2545 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
2548 node = mdb_search_node(mc, key, &exact);
2550 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
2552 assert(mc->mc_ki[mc->mc_top] > 0);
2553 mc->mc_ki[mc->mc_top]--;
2558 DPRINTF("following index %u for key [%s]",
2559 mc->mc_ki[mc->mc_top], DKEY(key));
2560 assert(mc->mc_ki[mc->mc_top] < NUMKEYS(mp));
2561 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
2563 if ((rc = mdb_get_page(mc->mc_txn, NODEPGNO(node), &mp)))
2566 if ((rc = cursor_push_page(mc, mp)))
2570 if ((rc = mdb_touch(mc)) != 0)
2572 mp = mc->mc_pg[mc->mc_top];
2577 DPRINTF("internal error, index points to a %02X page!?",
2579 return MDB_CORRUPTED;
2582 DPRINTF("found leaf page %lu for key [%s]", mp->mp_pgno,
2583 key ? DKEY(key) : NULL);
2588 /* Search for the page a given key should be in.
2589 * Pushes parent pages on the cursor stack.
2590 * If key is NULL, search for the lowest page (used by mdb_cursor_first).
2591 * If modify is true, visited pages are updated with new page numbers.
2594 mdb_search_page(MDB_cursor *mc, MDB_val *key, int modify)
2599 /* Make sure the txn is still viable, then find the root from
2600 * the txn's db table.
2602 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
2603 DPUTS("transaction has failed, must abort");
2606 root = mc->mc_txn->mt_dbs[mc->mc_dbi].md_root;
2608 if (root == P_INVALID) { /* Tree is empty. */
2609 DPUTS("tree is empty");
2610 return MDB_NOTFOUND;
2613 if ((rc = mdb_get_page(mc->mc_txn, root, &mc->mc_pg[0])))
2619 DPRINTF("db %u root page %lu has flags 0x%X",
2620 mc->mc_dbi, root, mc->mc_pg[0]->mp_flags);
2623 /* For sub-databases, update main root first */
2624 if (mc->mc_dbi > MAIN_DBI && !mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty) {
2626 mc2.mc_txn = mc->mc_txn;
2627 mc2.mc_dbi = MAIN_DBI;
2628 rc = mdb_search_page(&mc2, &mc->mc_txn->mt_dbxs[mc->mc_dbi].md_name, 1);
2631 mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty = 1;
2633 if (!F_ISSET(mc->mc_pg[0]->mp_flags, P_DIRTY)) {
2634 if ((rc = mdb_touch(mc)))
2636 mc->mc_txn->mt_dbs[mc->mc_dbi].md_root = mc->mc_pg[0]->mp_pgno;
2640 return mdb_search_page_root(mc, key, modify);
2644 mdb_read_data(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
2646 MDB_page *omp; /* overflow mpage */
2650 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
2651 data->mv_size = NODEDSZ(leaf);
2652 data->mv_data = NODEDATA(leaf);
2656 /* Read overflow data.
2658 data->mv_size = NODEDSZ(leaf);
2659 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
2660 if ((rc = mdb_get_page(txn, pgno, &omp))) {
2661 DPRINTF("read overflow page %lu failed", pgno);
2664 data->mv_data = METADATA(omp);
2670 mdb_get(MDB_txn *txn, MDB_dbi dbi,
2671 MDB_val *key, MDB_val *data)
2680 DPRINTF("===> get db %u key [%s]", dbi, DKEY(key));
2682 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
2685 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
2692 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
2693 mc.mc_xcursor = &mx;
2694 mdb_xcursor_init0(&mc);
2696 mc.mc_xcursor = NULL;
2698 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
2702 mdb_sibling(MDB_cursor *mc, int move_right)
2709 if (mc->mc_snum < 2) {
2710 return MDB_NOTFOUND; /* root has no siblings */
2712 ptop = mc->mc_top-1;
2714 DPRINTF("parent page is page %lu, index %u",
2715 mc->mc_pg[ptop]->mp_pgno, mc->mc_ki[ptop]);
2717 cursor_pop_page(mc);
2718 if (move_right ? (mc->mc_ki[ptop] + 1u >= NUMKEYS(mc->mc_pg[ptop]))
2719 : (mc->mc_ki[ptop] == 0)) {
2720 DPRINTF("no more keys left, moving to %s sibling",
2721 move_right ? "right" : "left");
2722 if ((rc = mdb_sibling(mc, move_right)) != MDB_SUCCESS)
2729 DPRINTF("just moving to %s index key %u",
2730 move_right ? "right" : "left", mc->mc_ki[ptop]);
2732 assert(IS_BRANCH(mc->mc_pg[ptop]));
2734 indx = NODEPTR(mc->mc_pg[ptop], mc->mc_ki[ptop]);
2735 if ((rc = mdb_get_page(mc->mc_txn, NODEPGNO(indx), &mp)))
2738 cursor_push_page(mc, mp);
2744 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
2750 if (mc->mc_flags & C_EOF) {
2751 return MDB_NOTFOUND;
2754 assert(mc->mc_flags & C_INITIALIZED);
2756 mp = mc->mc_pg[mc->mc_top];
2758 if (mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT) {
2759 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
2760 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2761 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
2762 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
2763 if (op != MDB_NEXT || rc == MDB_SUCCESS)
2767 mc->mc_xcursor->mx_cursor.mc_flags = 0;
2768 if (op == MDB_NEXT_DUP)
2769 return MDB_NOTFOUND;
2773 DPRINTF("cursor_next: top page is %lu in cursor %p", mp->mp_pgno, (void *) mc);
2775 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
2776 DPUTS("=====> move to next sibling page");
2777 if (mdb_sibling(mc, 1) != MDB_SUCCESS) {
2778 mc->mc_flags |= C_EOF;
2779 return MDB_NOTFOUND;
2781 mp = mc->mc_pg[mc->mc_top];
2782 DPRINTF("next page is %lu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
2784 mc->mc_ki[mc->mc_top]++;
2786 DPRINTF("==> cursor points to page %lu with %u keys, key index %u",
2787 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
2790 key->mv_size = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
2791 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
2795 assert(IS_LEAF(mp));
2796 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
2798 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2799 mdb_xcursor_init1(mc, leaf);
2802 if ((rc = mdb_read_data(mc->mc_txn, leaf, data) != MDB_SUCCESS))
2805 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2806 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
2807 if (rc != MDB_SUCCESS)
2812 MDB_SET_KEY(leaf, key);
2817 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
2823 assert(mc->mc_flags & C_INITIALIZED);
2825 mp = mc->mc_pg[mc->mc_top];
2827 if (mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT) {
2828 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
2829 if (op == MDB_PREV || op == MDB_PREV_DUP) {
2830 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2831 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
2832 if (op != MDB_PREV || rc == MDB_SUCCESS)
2835 mc->mc_xcursor->mx_cursor.mc_flags = 0;
2836 if (op == MDB_PREV_DUP)
2837 return MDB_NOTFOUND;
2842 DPRINTF("cursor_prev: top page is %lu in cursor %p", mp->mp_pgno, (void *) mc);
2844 if (mc->mc_ki[mc->mc_top] == 0) {
2845 DPUTS("=====> move to prev sibling page");
2846 if (mdb_sibling(mc, 0) != MDB_SUCCESS) {
2847 mc->mc_flags &= ~C_INITIALIZED;
2848 return MDB_NOTFOUND;
2850 mp = mc->mc_pg[mc->mc_top];
2851 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
2852 DPRINTF("prev page is %lu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]);
2854 mc->mc_ki[mc->mc_top]--;
2856 mc->mc_flags &= ~C_EOF;
2858 DPRINTF("==> cursor points to page %lu with %u keys, key index %u",
2859 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]);
2862 key->mv_size = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
2863 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
2867 assert(IS_LEAF(mp));
2868 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
2870 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2871 mdb_xcursor_init1(mc, leaf);
2874 if ((rc = mdb_read_data(mc->mc_txn, leaf, data) != MDB_SUCCESS))
2877 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2878 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
2879 if (rc != MDB_SUCCESS)
2884 MDB_SET_KEY(leaf, key);
2889 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
2890 MDB_cursor_op op, int *exactp)
2898 assert(key->mv_size > 0);
2900 /* See if we're already on the right page */
2901 if (mc->mc_flags & C_INITIALIZED) {
2904 if (mc->mc_pg[mc->mc_top]->mp_flags & P_LEAF2) {
2905 nodekey.mv_size = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
2906 nodekey.mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, nodekey.mv_size);
2908 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
2909 MDB_SET_KEY(leaf, &nodekey);
2911 rc = mc->mc_txn->mt_dbxs[mc->mc_dbi].md_cmp(key, &nodekey);
2913 /* Probably happens rarely, but first node on the page
2914 * was the one we wanted.
2916 mc->mc_ki[mc->mc_top] = 0;
2920 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
2925 if (NUMKEYS(mc->mc_pg[mc->mc_top]) > 1) {
2926 if (mc->mc_pg[mc->mc_top]->mp_flags & P_LEAF2) {
2927 nodekey.mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top],
2928 NUMKEYS(mc->mc_pg[mc->mc_top])-1, nodekey.mv_size);
2930 leaf = NODEPTR(mc->mc_pg[mc->mc_top], NUMKEYS(mc->mc_pg[mc->mc_top])-1);
2931 MDB_SET_KEY(leaf, &nodekey);
2933 rc = mc->mc_txn->mt_dbxs[mc->mc_dbi].md_cmp(key, &nodekey);
2935 /* last node was the one we wanted */
2936 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top])-1;
2940 /* This is definitely the right page, skip search_page */
2945 /* If any parents have right-sibs, search.
2946 * Otherwise, there's nothing further.
2948 for (i=0; i<mc->mc_top; i++)
2950 NUMKEYS(mc->mc_pg[i])-1)
2952 if (i == mc->mc_top) {
2953 /* There are no other pages */
2954 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
2955 return MDB_NOTFOUND;
2960 rc = mdb_search_page(mc, key, 0);
2961 if (rc != MDB_SUCCESS)
2964 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
2967 leaf = mdb_search_node(mc, key, exactp);
2968 if (exactp != NULL && !*exactp) {
2969 /* MDB_SET specified and not an exact match. */
2970 return MDB_NOTFOUND;
2974 DPUTS("===> inexact leaf not found, goto sibling");
2975 if ((rc = mdb_sibling(mc, 1)) != MDB_SUCCESS)
2976 return rc; /* no entries matched */
2977 mc->mc_ki[mc->mc_top] = 0;
2978 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
2979 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
2983 mc->mc_flags |= C_INITIALIZED;
2984 mc->mc_flags &= ~C_EOF;
2986 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
2987 key->mv_size = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
2988 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
2992 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2993 mdb_xcursor_init1(mc, leaf);
2996 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
2997 if (op == MDB_SET || op == MDB_SET_RANGE) {
2998 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
3001 if (op == MDB_GET_BOTH) {
3007 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
3008 if (rc != MDB_SUCCESS)
3011 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
3013 if ((rc = mdb_read_data(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
3015 rc = mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dcmp(data, &d2);
3017 if (op == MDB_GET_BOTH || rc > 0)
3018 return MDB_NOTFOUND;
3022 if ((rc = mdb_read_data(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
3027 /* The key already matches in all other cases */
3028 if (op == MDB_SET_RANGE)
3029 MDB_SET_KEY(leaf, key);
3030 DPRINTF("==> cursor placed on key [%s]", DKEY(key));
3036 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
3041 rc = mdb_search_page(mc, NULL, 0);
3042 if (rc != MDB_SUCCESS)
3044 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
3046 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
3047 mc->mc_flags |= C_INITIALIZED;
3048 mc->mc_flags &= ~C_EOF;
3050 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
3051 key->mv_size = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
3052 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
3057 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3058 mdb_xcursor_init1(mc, leaf);
3059 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
3064 mc->mc_xcursor->mx_cursor.mc_flags = 0;
3065 if ((rc = mdb_read_data(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
3069 MDB_SET_KEY(leaf, key);
3074 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
3080 lkey.mv_size = MAXKEYSIZE+1;
3081 lkey.mv_data = NULL;
3083 rc = mdb_search_page(mc, &lkey, 0);
3084 if (rc != MDB_SUCCESS)
3086 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
3088 leaf = NODEPTR(mc->mc_pg[mc->mc_top], NUMKEYS(mc->mc_pg[mc->mc_top])-1);
3089 mc->mc_flags |= C_INITIALIZED;
3090 mc->mc_flags &= ~C_EOF;
3092 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
3094 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
3095 key->mv_size = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
3096 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
3101 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3102 mdb_xcursor_init1(mc, leaf);
3103 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
3107 if ((rc = mdb_read_data(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
3112 MDB_SET_KEY(leaf, key);
3117 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
3127 case MDB_GET_BOTH_RANGE:
3128 if (data == NULL || mc->mc_xcursor == NULL) {
3135 if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
3137 } else if (op == MDB_SET_RANGE)
3138 rc = mdb_cursor_set(mc, key, data, op, NULL);
3140 rc = mdb_cursor_set(mc, key, data, op, &exact);
3142 case MDB_GET_MULTIPLE:
3144 !(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPFIXED) ||
3145 !(mc->mc_flags & C_INITIALIZED)) {
3150 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
3151 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
3154 case MDB_NEXT_MULTIPLE:
3156 !(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPFIXED)) {
3160 if (!(mc->mc_flags & C_INITIALIZED))
3161 rc = mdb_cursor_first(mc, key, data);
3163 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
3164 if (rc == MDB_SUCCESS) {
3165 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
3168 mx = &mc->mc_xcursor->mx_cursor;
3169 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
3170 mx->mc_txn->mt_dbs[mx->mc_dbi].md_pad;
3171 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
3172 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
3180 case MDB_NEXT_NODUP:
3181 if (!(mc->mc_flags & C_INITIALIZED))
3182 rc = mdb_cursor_first(mc, key, data);
3184 rc = mdb_cursor_next(mc, key, data, op);
3188 case MDB_PREV_NODUP:
3189 if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF))
3190 rc = mdb_cursor_last(mc, key, data);
3192 rc = mdb_cursor_prev(mc, key, data, op);
3195 rc = mdb_cursor_first(mc, key, data);
3199 !(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT) ||
3200 !(mc->mc_flags & C_INITIALIZED) ||
3201 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
3205 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
3208 rc = mdb_cursor_last(mc, key, data);
3212 !(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT) ||
3213 !(mc->mc_flags & C_INITIALIZED) ||
3214 !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
3218 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
3221 DPRINTF("unhandled/unimplemented cursor operation %u", op);
3230 mdb_cursor_touch(MDB_cursor *mc)
3234 if (mc->mc_dbi > MAIN_DBI && !mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty) {
3236 mc2.mc_txn = mc->mc_txn;
3237 mc2.mc_dbi = MAIN_DBI;
3238 rc = mdb_search_page(&mc2, &mc->mc_txn->mt_dbxs[mc->mc_dbi].md_name, 1);
3240 mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty = 1;
3242 for (mc->mc_top = 0; mc->mc_top < mc->mc_snum; mc->mc_top++) {
3243 if (!F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY)) {
3247 mc->mc_txn->mt_dbs[mc->mc_dbi].md_root =
3248 mc->mc_pg[mc->mc_top]->mp_pgno;
3252 mc->mc_top = mc->mc_snum-1;
3257 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
3261 MDB_val xdata, *rdata, dkey;
3263 char dbuf[PAGESIZE];
3269 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
3272 DPRINTF("==> put db %u key [%s], size %zu, data size %zu",
3273 mc->mc_dbi, DKEY(key), key->mv_size, data->mv_size);
3277 if (flags == MDB_CURRENT) {
3278 if (!(mc->mc_flags & C_INITIALIZED))
3281 } else if (mc->mc_txn->mt_dbs[mc->mc_dbi].md_root == P_INVALID) {
3283 /* new database, write a root leaf page */
3284 DPUTS("allocating new root leaf page");
3285 if ((np = mdb_new_page(mc, P_LEAF, 1)) == NULL) {
3289 cursor_push_page(mc, np);
3290 mc->mc_txn->mt_dbs[mc->mc_dbi].md_root = np->mp_pgno;
3291 mc->mc_txn->mt_dbs[mc->mc_dbi].md_depth++;
3292 mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty = 1;
3293 if ((mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
3295 np->mp_flags |= P_LEAF2;
3296 mc->mc_flags |= C_INITIALIZED;
3302 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
3303 if (flags == MDB_NOOVERWRITE && rc == 0) {
3304 DPRINTF("duplicate key [%s]", DKEY(key));
3306 return MDB_KEYEXIST;
3308 if (rc && rc != MDB_NOTFOUND)
3312 /* Cursor is positioned, now make sure all pages are writable */
3313 rc2 = mdb_cursor_touch(mc);
3314 if (rc2) return rc2;
3317 /* The key already exists */
3318 if (rc == MDB_SUCCESS) {
3319 /* there's only a key anyway, so this is a no-op */
3320 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
3321 unsigned int ksize = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
3322 if (key->mv_size != ksize)
3324 if (flags == MDB_CURRENT) {
3325 char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
3326 memcpy(ptr, key->mv_data, ksize);
3331 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
3334 if (F_ISSET(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags, MDB_DUPSORT)) {
3335 /* Was a single item before, must convert now */
3336 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3337 dkey.mv_size = NODEDSZ(leaf);
3338 dkey.mv_data = dbuf;
3339 memcpy(dbuf, NODEDATA(leaf), dkey.mv_size);
3340 /* data matches, ignore it */
3341 if (!mdb_dcmp(mc->mc_txn, mc->mc_dbi, data, &dkey))
3342 return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS;
3343 memset(&dummy, 0, sizeof(dummy));
3344 if (mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPFIXED) {
3345 dummy.md_pad = data->mv_size;
3346 dummy.md_flags = MDB_DUPFIXED;
3347 if (mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_INTEGERDUP)
3348 dummy.md_flags |= MDB_INTEGERKEY;
3350 dummy.md_root = P_INVALID;
3351 if (dkey.mv_size == sizeof(MDB_db)) {
3352 memcpy(NODEDATA(leaf), &dummy, sizeof(dummy));
3355 mdb_del_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
3358 xdata.mv_size = sizeof(MDB_db);
3359 xdata.mv_data = &dummy;
3360 /* new sub-DB, must fully init xcursor */
3361 if (flags == MDB_CURRENT)
3367 /* same size, just replace it */
3368 if (!F_ISSET(leaf->mn_flags, F_BIGDATA) &&
3369 NODEDSZ(leaf) == data->mv_size) {
3370 memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
3373 mdb_del_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
3375 DPRINTF("inserting key at index %i", mc->mc_ki[mc->mc_top]);
3381 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(mc->mc_txn->mt_env, key, rdata);
3382 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
3383 rc = mdb_split(mc, key, rdata, P_INVALID);
3385 /* There is room already in this leaf page. */
3386 rc = mdb_add_node(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, 0);
3389 if (rc != MDB_SUCCESS)
3390 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
3392 /* Remember if we just added a subdatabase */
3393 if (flags & F_SUBDATA) {
3394 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
3395 leaf->mn_flags |= F_SUBDATA;
3398 /* Now store the actual data in the child DB. Note that we're
3399 * storing the user data in the keys field, so there are strict
3400 * size limits on dupdata. The actual data fields of the child
3401 * DB are all zero size.
3404 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
3406 if (flags == MDB_CURRENT)
3407 mdb_xcursor_init2(mc);
3409 mdb_xcursor_init1(mc, leaf);
3412 if (flags == MDB_NODUPDATA)
3413 flags = MDB_NOOVERWRITE;
3414 /* converted, write the original data first */
3416 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, flags);
3418 leaf->mn_flags |= F_DUPDATA;
3420 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, flags);
3421 mdb_xcursor_fini(mc);
3422 memcpy(NODEDATA(leaf),
3423 &mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi],
3426 mc->mc_txn->mt_dbs[mc->mc_dbi].md_entries++;
3433 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
3438 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY))
3441 if (!mc->mc_flags & C_INITIALIZED)
3444 rc = mdb_cursor_touch(mc);
3447 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
3449 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3450 if (flags != MDB_NODUPDATA) {
3451 mdb_xcursor_init2(mc);
3452 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, 0);
3453 mdb_xcursor_fini(mc);
3454 /* If sub-DB still has entries, we're done */
3455 if (mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi].md_root
3457 memcpy(NODEDATA(leaf),
3458 &mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi],
3460 mc->mc_txn->mt_dbs[mc->mc_dbi].md_entries--;
3463 /* otherwise fall thru and delete the sub-DB */
3466 /* add all the child DB's pages to the free list */
3467 rc = mdb_search_page(&mc->mc_xcursor->mx_cursor, NULL, 0);
3468 if (rc == MDB_SUCCESS) {
3473 mx = &mc->mc_xcursor->mx_cursor;
3474 mc->mc_txn->mt_dbs[mc->mc_dbi].md_entries -=
3475 mx->mc_txn->mt_dbs[mx->mc_dbi].md_entries;
3477 cursor_pop_page(mx);
3479 while (mx->mc_snum > 1) {
3480 for (i=0; i<NUMKEYS(mx->mc_pg[mx->mc_top]); i++) {
3482 ni = NODEPTR(mx->mc_pg[mx->mc_top], i);
3485 mdb_midl_append(mc->mc_txn->mt_free_pgs, pg);
3487 rc = mdb_sibling(mx, 1);
3492 mdb_midl_append(mc->mc_txn->mt_free_pgs,
3493 mx->mc_txn->mt_dbs[mx->mc_dbi].md_root);
3497 return mdb_del0(mc, leaf);
3500 /* Allocate a page and initialize it
3503 mdb_new_page(MDB_cursor *mc, uint32_t flags, int num)
3507 if ((np = mdb_alloc_page(mc, num)) == NULL)
3509 DPRINTF("allocated new mpage %lu, page size %u",
3510 np->mp_pgno, mc->mc_txn->mt_env->me_psize);
3511 np->mp_flags = flags | P_DIRTY;
3512 np->mp_lower = PAGEHDRSZ;
3513 np->mp_upper = mc->mc_txn->mt_env->me_psize;
3516 mc->mc_txn->mt_dbs[mc->mc_dbi].md_branch_pages++;
3517 else if (IS_LEAF(np))
3518 mc->mc_txn->mt_dbs[mc->mc_dbi].md_leaf_pages++;
3519 else if (IS_OVERFLOW(np)) {
3520 mc->mc_txn->mt_dbs[mc->mc_dbi].md_overflow_pages += num;
3528 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
3532 sz = LEAFSIZE(key, data);
3533 if (data->mv_size >= env->me_psize / MDB_MINKEYS) {
3534 /* put on overflow page */
3535 sz -= data->mv_size - sizeof(pgno_t);
3539 return sz + sizeof(indx_t);
3543 mdb_branch_size(MDB_env *env, MDB_val *key)
3548 if (sz >= env->me_psize / MDB_MINKEYS) {
3549 /* put on overflow page */
3550 /* not implemented */
3551 /* sz -= key->size - sizeof(pgno_t); */
3554 return sz + sizeof(indx_t);
3558 mdb_add_node(MDB_cursor *mc, indx_t indx,
3559 MDB_val *key, MDB_val *data, pgno_t pgno, uint8_t flags)
3562 size_t node_size = NODESIZE;
3565 MDB_page *mp = mc->mc_pg[mc->mc_top];
3566 MDB_page *ofp = NULL; /* overflow page */
3569 assert(mp->mp_upper >= mp->mp_lower);
3571 DPRINTF("add to %s page %lu index %i, data size %zu key size %zu [%s]",
3572 IS_LEAF(mp) ? "leaf" : "branch",
3573 mp->mp_pgno, indx, data ? data->mv_size : 0,
3574 key ? key->mv_size : 0, key ? DKEY(key) : NULL);
3577 /* Move higher keys up one slot. */
3578 int ksize = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad, dif;
3579 char *ptr = LEAF2KEY(mp, indx, ksize);
3580 dif = NUMKEYS(mp) - indx;
3582 memmove(ptr+ksize, ptr, dif*ksize);
3583 /* insert new key */
3584 memcpy(ptr, key->mv_data, ksize);
3586 /* Just using these for counting */
3587 mp->mp_lower += sizeof(indx_t);
3588 mp->mp_upper -= ksize - sizeof(indx_t);
3593 node_size += key->mv_size;
3597 if (F_ISSET(flags, F_BIGDATA)) {
3598 /* Data already on overflow page. */
3599 node_size += sizeof(pgno_t);
3600 } else if (data->mv_size >= mc->mc_txn->mt_env->me_psize / MDB_MINKEYS) {
3601 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
3602 /* Put data on overflow page. */
3603 DPRINTF("data size is %zu, put on overflow page",
3605 node_size += sizeof(pgno_t);
3606 if ((ofp = mdb_new_page(mc, P_OVERFLOW, ovpages)) == NULL)
3608 DPRINTF("allocated overflow page %lu", ofp->mp_pgno);
3611 node_size += data->mv_size;
3614 node_size += node_size & 1;
3616 if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
3617 DPRINTF("not enough room in page %lu, got %u ptrs",
3618 mp->mp_pgno, NUMKEYS(mp));
3619 DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
3620 mp->mp_upper - mp->mp_lower);
3621 DPRINTF("node size = %zu", node_size);
3625 /* Move higher pointers up one slot. */
3626 for (i = NUMKEYS(mp); i > indx; i--)
3627 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
3629 /* Adjust free space offsets. */
3630 ofs = mp->mp_upper - node_size;
3631 assert(ofs >= mp->mp_lower + sizeof(indx_t));
3632 mp->mp_ptrs[indx] = ofs;
3634 mp->mp_lower += sizeof(indx_t);
3636 /* Write the node data. */
3637 node = NODEPTR(mp, indx);
3638 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
3639 node->mn_flags = flags;
3641 SETDSZ(node,data->mv_size);
3646 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
3651 if (F_ISSET(flags, F_BIGDATA))
3652 memcpy(node->mn_data + key->mv_size, data->mv_data,
3655 memcpy(node->mn_data + key->mv_size, data->mv_data,
3658 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
3660 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
3668 mdb_del_node(MDB_page *mp, indx_t indx, int ksize)
3671 indx_t i, j, numkeys, ptr;
3675 DPRINTF("delete node %u on %s page %lu", indx,
3676 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno);
3677 assert(indx < NUMKEYS(mp));
3680 int x = NUMKEYS(mp) - 1 - indx;
3681 base = LEAF2KEY(mp, indx, ksize);
3683 memmove(base, base + ksize, x * ksize);
3684 mp->mp_lower -= sizeof(indx_t);
3685 mp->mp_upper += ksize - sizeof(indx_t);
3689 node = NODEPTR(mp, indx);
3690 sz = NODESIZE + node->mn_ksize;
3692 if (F_ISSET(node->mn_flags, F_BIGDATA))
3693 sz += sizeof(pgno_t);
3695 sz += NODEDSZ(node);
3699 ptr = mp->mp_ptrs[indx];
3700 numkeys = NUMKEYS(mp);
3701 for (i = j = 0; i < numkeys; i++) {
3703 mp->mp_ptrs[j] = mp->mp_ptrs[i];
3704 if (mp->mp_ptrs[i] < ptr)
3705 mp->mp_ptrs[j] += sz;
3710 base = (char *)mp + mp->mp_upper;
3711 memmove(base + sz, base, ptr - mp->mp_upper);
3713 mp->mp_lower -= sizeof(indx_t);
3718 mdb_xcursor_init0(MDB_cursor *mc)
3720 MDB_xcursor *mx = mc->mc_xcursor;
3723 mx->mx_txn = *mc->mc_txn;
3724 mx->mx_txn.mt_dbxs = mx->mx_dbxs;
3725 mx->mx_txn.mt_dbs = mx->mx_dbs;
3726 mx->mx_dbxs[0] = mc->mc_txn->mt_dbxs[0];
3727 mx->mx_dbxs[1] = mc->mc_txn->mt_dbxs[1];
3728 if (mc->mc_dbi > 1) {
3729 mx->mx_dbxs[2] = mc->mc_txn->mt_dbxs[mc->mc_dbi];
3734 mx->mx_dbxs[dbn+1].md_parent = dbn;
3735 mx->mx_dbxs[dbn+1].md_cmp = mx->mx_dbxs[dbn].md_dcmp;
3736 mx->mx_dbxs[dbn+1].md_rel = mx->mx_dbxs[dbn].md_rel;
3737 mx->mx_dbxs[dbn+1].md_dirty = 0;
3738 mx->mx_txn.mt_numdbs = dbn+2;
3739 mx->mx_txn.mt_u = mc->mc_txn->mt_u;
3741 mx->mx_cursor.mc_xcursor = NULL;
3742 mx->mx_cursor.mc_txn = &mx->mx_txn;
3743 mx->mx_cursor.mc_dbi = dbn+1;
3747 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
3749 MDB_db *db = NODEDATA(node);
3750 MDB_xcursor *mx = mc->mc_xcursor;
3752 mx->mx_dbs[0] = mc->mc_txn->mt_dbs[0];
3753 mx->mx_dbs[1] = mc->mc_txn->mt_dbs[1];
3754 if (mc->mc_dbi > 1) {
3755 mx->mx_dbs[2] = mc->mc_txn->mt_dbs[mc->mc_dbi];
3756 mx->mx_dbxs[2].md_dirty = mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty;
3761 DPRINTF("Sub-db %u for db %u root page %lu", dbn, mc->mc_dbi, db->md_root);
3762 mx->mx_dbs[dbn] = *db;
3763 if (F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY))
3764 mx->mx_dbxs[dbn].md_dirty = 1;
3765 mx->mx_dbxs[dbn].md_name.mv_data = NODEKEY(node);
3766 mx->mx_dbxs[dbn].md_name.mv_size = node->mn_ksize;
3767 mx->mx_txn.mt_next_pgno = mc->mc_txn->mt_next_pgno;
3768 mx->mx_cursor.mc_snum = 0;
3769 mx->mx_cursor.mc_flags = 0;
3773 mdb_xcursor_init2(MDB_cursor *mc)
3775 MDB_xcursor *mx = mc->mc_xcursor;
3777 mx->mx_dbs[0] = mc->mc_txn->mt_dbs[0];
3778 mx->mx_dbs[1] = mc->mc_txn->mt_dbs[1];
3779 if (mc->mc_dbi > 1) {
3780 mx->mx_dbs[2] = mc->mc_txn->mt_dbs[mc->mc_dbi];
3781 mx->mx_dbxs[2].md_dirty = mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty;
3786 DPRINTF("Sub-db %u for db %u root page %lu", dbn, mc->mc_dbi,
3787 mx->mx_dbs[dbn].md_root);
3788 mx->mx_txn.mt_next_pgno = mc->mc_txn->mt_next_pgno;
3792 mdb_xcursor_fini(MDB_cursor *mc)
3794 MDB_xcursor *mx = mc->mc_xcursor;
3795 mc->mc_txn->mt_next_pgno = mx->mx_txn.mt_next_pgno;
3796 mc->mc_txn->mt_dbs[0] = mx->mx_dbs[0];
3797 mc->mc_txn->mt_dbs[1] = mx->mx_dbs[1];
3798 if (mc->mc_dbi > 1) {
3799 mc->mc_txn->mt_dbs[mc->mc_dbi] = mx->mx_dbs[2];
3800 mc->mc_txn->mt_dbxs[mc->mc_dbi].md_dirty = mx->mx_dbxs[2].md_dirty;
3805 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
3808 size_t size = sizeof(MDB_cursor);
3810 if (txn == NULL || ret == NULL || !dbi || dbi >= txn->mt_numdbs)
3813 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
3814 size += sizeof(MDB_xcursor);
3816 if ((mc = calloc(1, size)) != NULL) {
3819 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
3820 MDB_xcursor *mx = (MDB_xcursor *)(mc + 1);
3821 mc->mc_xcursor = mx;
3822 mdb_xcursor_init0(mc);
3833 /* Return the count of duplicate data items for the current key */
3835 mdb_cursor_count(MDB_cursor *mc, unsigned long *countp)
3839 if (mc == NULL || countp == NULL)
3842 if (!(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT))
3845 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
3846 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
3849 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
3852 *countp = mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi].md_entries;
3858 mdb_cursor_close(MDB_cursor *mc)
3866 mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key)
3868 indx_t ptr, i, numkeys;
3875 node = NODEPTR(mp, indx);
3876 ptr = mp->mp_ptrs[indx];
3877 DPRINTF("update key %u (ofs %u) [%.*s] to [%s] on page %lu",
3879 (int)node->mn_ksize, (char *)NODEKEY(node),
3883 delta = key->mv_size - node->mn_ksize;
3885 if (delta > 0 && SIZELEFT(mp) < delta) {
3886 DPRINTF("OUCH! Not enough room, delta = %d", delta);
3890 numkeys = NUMKEYS(mp);
3891 for (i = 0; i < numkeys; i++) {
3892 if (mp->mp_ptrs[i] <= ptr)
3893 mp->mp_ptrs[i] -= delta;
3896 base = (char *)mp + mp->mp_upper;
3897 len = ptr - mp->mp_upper + NODESIZE;
3898 memmove(base - delta, base, len);
3899 mp->mp_upper -= delta;
3901 node = NODEPTR(mp, indx);
3902 node->mn_ksize = key->mv_size;
3905 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
3910 /* Move a node from csrc to cdst.
3913 mdb_move_node(MDB_cursor *csrc, MDB_cursor *cdst)
3920 /* Mark src and dst as dirty. */
3921 if ((rc = mdb_touch(csrc)) ||
3922 (rc = mdb_touch(cdst)))
3925 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
3926 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */
3927 key.mv_size = csrc->mc_txn->mt_dbs[csrc->mc_dbi].md_pad;
3928 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
3930 data.mv_data = NULL;
3932 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
3933 unsigned int snum = csrc->mc_snum;
3934 /* must find the lowest key below src */
3935 mdb_search_page_root(csrc, NULL, 0);
3936 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
3937 csrc->mc_snum = snum--;
3938 csrc->mc_top = snum;
3940 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
3942 key.mv_size = NODEKSZ(srcnode);
3943 key.mv_data = NODEKEY(srcnode);
3944 data.mv_size = NODEDSZ(srcnode);
3945 data.mv_data = NODEDATA(srcnode);
3947 DPRINTF("moving %s node %u [%s] on page %lu to node %u on page %lu",
3948 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
3949 csrc->mc_ki[csrc->mc_top],
3951 csrc->mc_pg[csrc->mc_top]->mp_pgno,
3952 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno);
3954 /* Add the node to the destination page.
3956 rc = mdb_add_node(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, NODEPGNO(srcnode),
3958 if (rc != MDB_SUCCESS)
3961 /* Delete the node from the source page.
3963 mdb_del_node(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
3965 /* Update the parent separators.
3967 if (csrc->mc_ki[csrc->mc_top] == 0) {
3968 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
3969 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
3970 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
3972 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
3973 key.mv_size = NODEKSZ(srcnode);
3974 key.mv_data = NODEKEY(srcnode);
3976 DPRINTF("update separator for source page %lu to [%s]",
3977 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key));
3978 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1],
3979 &key)) != MDB_SUCCESS)
3982 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
3984 nullkey.mv_size = 0;
3985 assert(mdb_update_key(csrc->mc_pg[csrc->mc_top], 0, &nullkey) == MDB_SUCCESS);
3989 if (cdst->mc_ki[cdst->mc_top] == 0) {
3990 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
3991 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
3992 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
3994 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
3995 key.mv_size = NODEKSZ(srcnode);
3996 key.mv_data = NODEKEY(srcnode);
3998 DPRINTF("update separator for destination page %lu to [%s]",
3999 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key));
4000 if ((rc = mdb_update_key(cdst->mc_pg[cdst->mc_top-1], cdst->mc_ki[cdst->mc_top-1],
4001 &key)) != MDB_SUCCESS)
4004 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
4006 nullkey.mv_size = 0;
4007 assert(mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &nullkey) == MDB_SUCCESS);
4015 mdb_merge(MDB_cursor *csrc, MDB_cursor *cdst)
4022 DPRINTF("merging page %lu into %lu", csrc->mc_pg[csrc->mc_top]->mp_pgno, cdst->mc_pg[cdst->mc_top]->mp_pgno);
4024 assert(csrc->mc_snum > 1); /* can't merge root page */
4025 assert(cdst->mc_snum > 1);
4027 /* Mark dst as dirty. */
4028 if ((rc = mdb_touch(cdst)))
4031 /* Move all nodes from src to dst.
4033 j = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
4034 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
4035 key.mv_size = csrc->mc_txn->mt_dbs[csrc->mc_dbi].md_pad;
4036 key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
4037 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
4038 rc = mdb_add_node(cdst, j, &key, NULL, 0, 0);
4039 if (rc != MDB_SUCCESS)
4041 key.mv_data = (char *)key.mv_data + key.mv_size;
4044 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
4045 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
4047 key.mv_size = srcnode->mn_ksize;
4048 key.mv_data = NODEKEY(srcnode);
4049 data.mv_size = NODEDSZ(srcnode);
4050 data.mv_data = NODEDATA(srcnode);
4051 rc = mdb_add_node(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
4052 if (rc != MDB_SUCCESS)
4057 DPRINTF("dst page %lu now has %u keys (%.1f%% filled)",
4058 cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]), (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10);
4060 /* Unlink the src page from parent and add to free list.
4062 mdb_del_node(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0);
4063 if (csrc->mc_ki[csrc->mc_top-1] == 0) {
4065 if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], 0, &key)) != MDB_SUCCESS)
4069 mdb_midl_append(csrc->mc_txn->mt_free_pgs, csrc->mc_pg[csrc->mc_top]->mp_pgno);
4070 if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
4071 csrc->mc_txn->mt_dbs[csrc->mc_dbi].md_leaf_pages--;
4073 csrc->mc_txn->mt_dbs[csrc->mc_dbi].md_branch_pages--;
4074 cursor_pop_page(csrc);
4076 return mdb_rebalance(csrc);
4080 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
4084 cdst->mc_txn = csrc->mc_txn;
4085 cdst->mc_dbi = csrc->mc_dbi;
4086 cdst->mc_snum = csrc->mc_snum;
4087 cdst->mc_top = csrc->mc_top;
4088 cdst->mc_flags = csrc->mc_flags;
4090 for (i=0; i<csrc->mc_snum; i++) {
4091 cdst->mc_pg[i] = csrc->mc_pg[i];
4092 cdst->mc_ki[i] = csrc->mc_ki[i];
4097 mdb_rebalance(MDB_cursor *mc)
4105 DPRINTF("rebalancing %s page %lu (has %u keys, %.1f%% full)",
4106 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
4107 mc->mc_pg[mc->mc_top]->mp_pgno, NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10);
4109 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD) {
4110 DPRINTF("no need to rebalance page %lu, above fill threshold",
4111 mc->mc_pg[mc->mc_top]->mp_pgno);
4115 if (mc->mc_snum < 2) {
4116 if (NUMKEYS(mc->mc_pg[mc->mc_top]) == 0) {
4117 DPUTS("tree is completely empty");
4118 mc->mc_txn->mt_dbs[mc->mc_dbi].md_root = P_INVALID;
4119 mc->mc_txn->mt_dbs[mc->mc_dbi].md_depth = 0;
4120 mc->mc_txn->mt_dbs[mc->mc_dbi].md_leaf_pages = 0;
4121 mdb_midl_append(mc->mc_txn->mt_free_pgs, mc->mc_pg[mc->mc_top]->mp_pgno);
4122 } else if (IS_BRANCH(mc->mc_pg[mc->mc_top]) && NUMKEYS(mc->mc_pg[mc->mc_top]) == 1) {
4123 DPUTS("collapsing root page!");
4124 mdb_midl_append(mc->mc_txn->mt_free_pgs, mc->mc_pg[mc->mc_top]->mp_pgno);
4125 mc->mc_txn->mt_dbs[mc->mc_dbi].md_root = NODEPGNO(NODEPTR(mc->mc_pg[mc->mc_top], 0));
4126 if ((rc = mdb_get_page(mc->mc_txn, mc->mc_txn->mt_dbs[mc->mc_dbi].md_root, &root)))
4128 mc->mc_txn->mt_dbs[mc->mc_dbi].md_depth--;
4129 mc->mc_txn->mt_dbs[mc->mc_dbi].md_branch_pages--;
4131 DPUTS("root page doesn't need rebalancing");
4135 /* The parent (branch page) must have at least 2 pointers,
4136 * otherwise the tree is invalid.
4138 ptop = mc->mc_top-1;
4139 assert(NUMKEYS(mc->mc_pg[ptop]) > 1);
4141 /* Leaf page fill factor is below the threshold.
4142 * Try to move keys from left or right neighbor, or
4143 * merge with a neighbor page.
4148 mdb_cursor_copy(mc, &mn);
4149 mn.mc_xcursor = NULL;
4151 if (mc->mc_ki[ptop] == 0) {
4152 /* We're the leftmost leaf in our parent.
4154 DPUTS("reading right neighbor");
4156 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
4157 if ((rc = mdb_get_page(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
4159 mn.mc_ki[mn.mc_top] = 0;
4160 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
4162 /* There is at least one neighbor to the left.
4164 DPUTS("reading left neighbor");
4166 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
4167 if ((rc = mdb_get_page(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top])))
4169 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
4170 mc->mc_ki[mc->mc_top] = 0;
4173 DPRINTF("found neighbor page %lu (%u keys, %.1f%% full)",
4174 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10);
4176 /* If the neighbor page is above threshold and has at least two
4177 * keys, move one key from it.
4179 * Otherwise we should try to merge them.
4181 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) >= 2)
4182 return mdb_move_node(&mn, mc);
4183 else { /* FIXME: if (has_enough_room()) */
4184 if (mc->mc_ki[ptop] == 0)
4185 return mdb_merge(&mn, mc);
4187 return mdb_merge(mc, &mn);
4192 mdb_del0(MDB_cursor *mc, MDB_node *leaf)
4196 /* add overflow pages to free list */
4197 if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_BIGDATA)) {
4201 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
4202 ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize);
4203 for (i=0; i<ovpages; i++) {
4204 DPRINTF("freed ov page %lu", pg);
4205 mdb_midl_append(mc->mc_txn->mt_free_pgs, pg);
4209 mdb_del_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad);
4210 mc->mc_txn->mt_dbs[mc->mc_dbi].md_entries--;
4211 rc = mdb_rebalance(mc);
4212 if (rc != MDB_SUCCESS)
4213 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
4219 mdb_del(MDB_txn *txn, MDB_dbi dbi,
4220 MDB_val *key, MDB_val *data)
4225 MDB_val rdata, *xdata;
4229 assert(key != NULL);
4231 DPRINTF("====> delete db %u key [%s]", dbi, DKEY(key));
4233 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
4236 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
4240 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
4247 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
4248 mc.mc_xcursor = &mx;
4249 mdb_xcursor_init0(&mc);
4251 mc.mc_xcursor = NULL;
4263 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
4265 rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA);
4269 /* Split page <mc->top>, and insert <key,(data|newpgno)> in either left or
4270 * right sibling, at index <mc->ki> (as if unsplit). Updates mc->top and
4271 * mc->ki with the actual values after split, ie if mc->top and mc->ki
4272 * refer to a node in the new right sibling page.
4275 mdb_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno)
4278 int rc = MDB_SUCCESS, ins_new = 0;
4281 unsigned int i, j, split_indx, nkeys, pmax;
4283 MDB_val sepkey, rkey, rdata;
4285 MDB_page *mp, *rp, *pp;
4290 mp = mc->mc_pg[mc->mc_top];
4291 newindx = mc->mc_ki[mc->mc_top];
4293 DPRINTF("-----> splitting %s page %lu and adding [%s] at index %i",
4294 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
4295 DKEY(newkey), mc->mc_ki[mc->mc_top]);
4297 if (mc->mc_snum < 2) {
4298 if ((pp = mdb_new_page(mc, P_BRANCH, 1)) == NULL)
4300 /* shift current top to make room for new parent */
4301 mc->mc_pg[1] = mc->mc_pg[0];
4302 mc->mc_ki[1] = mc->mc_ki[0];
4305 mc->mc_txn->mt_dbs[mc->mc_dbi].md_root = pp->mp_pgno;
4306 DPRINTF("root split! new root = %lu", pp->mp_pgno);
4307 mc->mc_txn->mt_dbs[mc->mc_dbi].md_depth++;
4309 /* Add left (implicit) pointer. */
4310 if ((rc = mdb_add_node(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
4311 /* undo the pre-push */
4312 mc->mc_pg[0] = mc->mc_pg[1];
4313 mc->mc_ki[0] = mc->mc_ki[1];
4314 mc->mc_txn->mt_dbs[mc->mc_dbi].md_root = mp->mp_pgno;
4315 mc->mc_txn->mt_dbs[mc->mc_dbi].md_depth--;
4322 ptop = mc->mc_top-1;
4323 DPRINTF("parent branch page is %lu", mc->mc_pg[ptop]->mp_pgno);
4326 /* Create a right sibling. */
4327 if ((rp = mdb_new_page(mc, mp->mp_flags, 1)) == NULL)
4329 mdb_cursor_copy(mc, &mn);
4330 mn.mc_pg[mn.mc_top] = rp;
4331 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
4332 DPRINTF("new right sibling: page %lu", rp->mp_pgno);
4334 nkeys = NUMKEYS(mp);
4335 split_indx = nkeys / 2 + 1;
4340 unsigned int lsize, rsize, ksize;
4341 /* Move half of the keys to the right sibling */
4343 x = mc->mc_ki[mc->mc_top] - split_indx;
4344 ksize = mc->mc_txn->mt_dbs[mc->mc_dbi].md_pad;
4345 split = LEAF2KEY(mp, split_indx, ksize);
4346 rsize = (nkeys - split_indx) * ksize;
4347 lsize = (nkeys - split_indx) * sizeof(indx_t);
4348 mp->mp_lower -= lsize;
4349 rp->mp_lower += lsize;
4350 mp->mp_upper += rsize - lsize;
4351 rp->mp_upper -= rsize - lsize;
4352 sepkey.mv_size = ksize;
4353 if (newindx == split_indx) {
4354 sepkey.mv_data = newkey->mv_data;
4356 sepkey.mv_data = split;
4359 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
4360 memcpy(rp->mp_ptrs, split, rsize);
4361 sepkey.mv_data = rp->mp_ptrs;
4362 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
4363 memcpy(ins, newkey->mv_data, ksize);
4364 mp->mp_lower += sizeof(indx_t);
4365 mp->mp_upper -= ksize - sizeof(indx_t);
4368 memcpy(rp->mp_ptrs, split, x * ksize);
4369 ins = LEAF2KEY(rp, x, ksize);
4370 memcpy(ins, newkey->mv_data, ksize);
4371 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
4372 rp->mp_lower += sizeof(indx_t);
4373 rp->mp_upper -= ksize - sizeof(indx_t);
4374 mc->mc_ki[mc->mc_top] = x;
4375 mc->mc_pg[mc->mc_top] = rp;
4380 /* For leaf pages, check the split point based on what
4381 * fits where, since otherwise add_node can fail.
4384 unsigned int psize, nsize;
4385 /* Maximum free space in an empty page */
4386 pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ;
4387 nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata);
4388 if (newindx < split_indx) {
4390 for (i=0; i<split_indx; i++) {
4391 node = NODEPTR(mp, i);
4392 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
4393 if (F_ISSET(node->mn_flags, F_BIGDATA))
4394 psize += sizeof(pgno_t);
4396 psize += NODEDSZ(node);
4405 for (i=nkeys-1; i>=split_indx; i--) {
4406 node = NODEPTR(mp, i);
4407 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
4408 if (F_ISSET(node->mn_flags, F_BIGDATA))
4409 psize += sizeof(pgno_t);
4411 psize += NODEDSZ(node);
4421 /* First find the separating key between the split pages.
4423 if (newindx == split_indx) {
4424 sepkey.mv_size = newkey->mv_size;
4425 sepkey.mv_data = newkey->mv_data;
4427 node = NODEPTR(mp, split_indx);
4428 sepkey.mv_size = node->mn_ksize;
4429 sepkey.mv_data = NODEKEY(node);
4433 DPRINTF("separator is [%s]", DKEY(&sepkey));
4435 /* Copy separator key to the parent.
4437 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) {
4440 rc = mdb_split(&mn, &sepkey, NULL, rp->mp_pgno);
4442 /* Right page might now have changed parent.
4443 * Check if left page also changed parent.
4445 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
4446 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
4447 mc->mc_pg[ptop] = mn.mc_pg[ptop];
4448 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
4452 rc = mdb_add_node(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
4458 if (rc != MDB_SUCCESS) {
4462 /* Move half of the keys to the right sibling. */
4464 /* grab a page to hold a temporary copy */
4465 if (mc->mc_txn->mt_env->me_dpages) {
4466 copy = mc->mc_txn->mt_env->me_dpages;
4467 mc->mc_txn->mt_env->me_dpages = copy->mp_next;
4469 if ((copy = malloc(mc->mc_txn->mt_env->me_psize)) == NULL)
4473 copy->mp_pgno = mp->mp_pgno;
4474 copy->mp_flags = mp->mp_flags;
4475 copy->mp_lower = PAGEHDRSZ;
4476 copy->mp_upper = mc->mc_txn->mt_env->me_psize;
4477 mc->mc_pg[mc->mc_top] = copy;
4478 for (i = j = 0; i <= nkeys; j++) {
4479 if (i == split_indx) {
4480 /* Insert in right sibling. */
4481 /* Reset insert index for right sibling. */
4482 j = (i == newindx && ins_new);
4483 mc->mc_pg[mc->mc_top] = rp;
4486 if (i == newindx && !ins_new) {
4487 /* Insert the original entry that caused the split. */
4488 rkey.mv_data = newkey->mv_data;
4489 rkey.mv_size = newkey->mv_size;
4491 rdata.mv_data = newdata->mv_data;
4492 rdata.mv_size = newdata->mv_size;
4499 /* Update page and index for the new key. */
4500 mc->mc_ki[mc->mc_top] = j;
4501 } else if (i == nkeys) {
4504 node = NODEPTR(mp, i);
4505 rkey.mv_data = NODEKEY(node);
4506 rkey.mv_size = node->mn_ksize;
4508 rdata.mv_data = NODEDATA(node);
4509 rdata.mv_size = NODEDSZ(node);
4511 pgno = NODEPGNO(node);
4512 flags = node->mn_flags;
4517 if (!IS_LEAF(mp) && j == 0) {
4518 /* First branch index doesn't need key data. */
4522 rc = mdb_add_node(mc, j, &rkey, &rdata, pgno, flags);
4525 /* reset back to original page */
4526 if (newindx < split_indx)
4527 mc->mc_pg[mc->mc_top] = mp;
4529 nkeys = NUMKEYS(copy);
4530 for (i=0; i<nkeys; i++)
4531 mp->mp_ptrs[i] = copy->mp_ptrs[i];
4532 mp->mp_lower = copy->mp_lower;
4533 mp->mp_upper = copy->mp_upper;
4534 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
4535 mc->mc_txn->mt_env->me_psize - copy->mp_upper);
4537 /* return tmp page to freelist */
4538 copy->mp_next = mc->mc_txn->mt_env->me_dpages;
4539 mc->mc_txn->mt_env->me_dpages = copy;
4544 mdb_put(MDB_txn *txn, MDB_dbi dbi,
4545 MDB_val *key, MDB_val *data, unsigned int flags)
4550 assert(key != NULL);
4551 assert(data != NULL);
4553 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
4556 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
4560 if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
4564 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA)) != flags)
4571 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
4572 mc.mc_xcursor = &mx;
4573 mdb_xcursor_init0(&mc);
4575 mc.mc_xcursor = NULL;
4577 return mdb_cursor_put(&mc, key, data, flags);
4581 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
4583 /** Only a subset of the @ref mdb_env flags can be changed
4584 * at runtime. Changing other flags requires closing the environment
4585 * and re-opening it with the new flags.
4587 #define CHANGEABLE (MDB_NOSYNC)
4588 if ((flag & CHANGEABLE) != flag)
4591 env->me_flags |= flag;
4593 env->me_flags &= ~flag;
4598 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
4603 *arg = env->me_flags;
4608 mdb_env_get_path(MDB_env *env, const char **arg)
4613 *arg = env->me_path;
4618 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
4620 arg->ms_psize = env->me_psize;
4621 arg->ms_depth = db->md_depth;
4622 arg->ms_branch_pages = db->md_branch_pages;
4623 arg->ms_leaf_pages = db->md_leaf_pages;
4624 arg->ms_overflow_pages = db->md_overflow_pages;
4625 arg->ms_entries = db->md_entries;
4630 mdb_env_stat(MDB_env *env, MDB_stat *arg)
4634 if (env == NULL || arg == NULL)
4637 mdb_env_read_meta(env, &toggle);
4639 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
4643 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
4645 if (txn->mt_dbs[dbi].md_flags & MDB_REVERSEKEY)
4646 txn->mt_dbxs[dbi].md_cmp = memnrcmp;
4647 else if (txn->mt_dbs[dbi].md_flags & MDB_INTEGERKEY)
4648 txn->mt_dbxs[dbi].md_cmp = cintcmp;
4650 txn->mt_dbxs[dbi].md_cmp = memncmp;
4652 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
4653 if (txn->mt_dbs[dbi].md_flags & MDB_INTEGERDUP) {
4654 if (txn->mt_dbs[dbi].md_flags & MDB_DUPFIXED)
4655 txn->mt_dbxs[dbi].md_dcmp = intcmp;
4657 txn->mt_dbxs[dbi].md_dcmp = cintcmp;
4658 } else if (txn->mt_dbs[dbi].md_flags & MDB_REVERSEDUP) {
4659 txn->mt_dbxs[dbi].md_dcmp = memnrcmp;
4661 txn->mt_dbxs[dbi].md_dcmp = memncmp;
4664 txn->mt_dbxs[dbi].md_dcmp = NULL;
4668 int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
4675 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
4676 mdb_default_cmp(txn, FREE_DBI);
4682 if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY))
4683 txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY));
4684 mdb_default_cmp(txn, MAIN_DBI);
4688 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
4689 mdb_default_cmp(txn, MAIN_DBI);
4692 /* Is the DB already open? */
4694 for (i=2; i<txn->mt_numdbs; i++) {
4695 if (len == txn->mt_dbxs[i].md_name.mv_size &&
4696 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
4702 if (txn->mt_numdbs >= txn->mt_env->me_maxdbs - 1)
4705 /* Find the DB info */
4707 key.mv_data = (void *)name;
4708 rc = mdb_get(txn, MAIN_DBI, &key, &data);
4710 /* Create if requested */
4711 if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
4714 data.mv_size = sizeof(MDB_db);
4715 data.mv_data = &dummy;
4716 memset(&dummy, 0, sizeof(dummy));
4717 dummy.md_root = P_INVALID;
4718 dummy.md_flags = flags & 0xffff;
4720 mc.mc_dbi = MAIN_DBI;
4722 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
4726 /* OK, got info, add to table */
4727 if (rc == MDB_SUCCESS) {
4728 txn->mt_dbxs[txn->mt_numdbs].md_name.mv_data = strdup(name);
4729 txn->mt_dbxs[txn->mt_numdbs].md_name.mv_size = len;
4730 txn->mt_dbxs[txn->mt_numdbs].md_rel = NULL;
4731 txn->mt_dbxs[txn->mt_numdbs].md_parent = MAIN_DBI;
4732 txn->mt_dbxs[txn->mt_numdbs].md_dirty = dirty;
4733 memcpy(&txn->mt_dbs[txn->mt_numdbs], data.mv_data, sizeof(MDB_db));
4734 *dbi = txn->mt_numdbs;
4735 txn->mt_env->me_dbs[0][txn->mt_numdbs] = txn->mt_dbs[txn->mt_numdbs];
4736 txn->mt_env->me_dbs[1][txn->mt_numdbs] = txn->mt_dbs[txn->mt_numdbs];
4737 mdb_default_cmp(txn, txn->mt_numdbs);
4744 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
4746 if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
4749 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
4752 void mdb_close(MDB_txn *txn, MDB_dbi dbi)
4755 if (dbi <= MAIN_DBI || dbi >= txn->mt_numdbs)
4757 ptr = txn->mt_dbxs[dbi].md_name.mv_data;
4758 txn->mt_dbxs[dbi].md_name.mv_data = NULL;
4759 txn->mt_dbxs[dbi].md_name.mv_size = 0;
4763 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
4765 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
4768 txn->mt_dbxs[dbi].md_cmp = cmp;
4772 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
4774 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
4777 txn->mt_dbxs[dbi].md_dcmp = cmp;
4781 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
4783 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs)
4786 txn->mt_dbxs[dbi].md_rel = rel;