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 2011-2013 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.
38 #include <sys/types.h>
42 /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
43 * as int64 which is wrong. MSVC doesn't define it at all, so just
48 # include <sys/param.h>
50 # define LITTLE_ENDIAN 1234
51 # define BIG_ENDIAN 4321
52 # define BYTE_ORDER LITTLE_ENDIAN
54 # define SSIZE_MAX INT_MAX
58 #define MDB_PID_T pid_t
59 #include <sys/param.h>
62 #ifdef HAVE_SYS_FILE_H
79 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
80 #include <netinet/in.h>
81 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
84 #if defined(__APPLE__) || defined (BSD)
85 # define MDB_USE_POSIX_SEM 1
86 # define MDB_FDATASYNC fsync
87 #elif defined(ANDROID)
88 # define MDB_FDATASYNC fsync
93 #ifdef MDB_USE_POSIX_SEM
94 # define MDB_USE_HASH 1
95 #include <semaphore.h>
100 #include <valgrind/memcheck.h>
101 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
102 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
103 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
104 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
105 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
107 #define VGMEMP_CREATE(h,r,z)
108 #define VGMEMP_ALLOC(h,a,s)
109 #define VGMEMP_FREE(h,a)
110 #define VGMEMP_DESTROY(h)
111 #define VGMEMP_DEFINED(a,s)
115 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
116 /* Solaris just defines one or the other */
117 # define LITTLE_ENDIAN 1234
118 # define BIG_ENDIAN 4321
119 # ifdef _LITTLE_ENDIAN
120 # define BYTE_ORDER LITTLE_ENDIAN
122 # define BYTE_ORDER BIG_ENDIAN
125 # define BYTE_ORDER __BYTE_ORDER
129 #ifndef LITTLE_ENDIAN
130 #define LITTLE_ENDIAN __LITTLE_ENDIAN
133 #define BIG_ENDIAN __BIG_ENDIAN
136 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
137 #define MISALIGNED_OK 1
143 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
144 # error "Unknown or unsupported endianness (BYTE_ORDER)"
145 #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
146 # error "Two's complement, reasonably sized integer types, please"
149 /** @defgroup internal MDB Internals
152 /** @defgroup compat Windows Compatibility Macros
153 * A bunch of macros to minimize the amount of platform-specific ifdefs
154 * needed throughout the rest of the code. When the features this library
155 * needs are similar enough to POSIX to be hidden in a one-or-two line
156 * replacement, this macro approach is used.
160 #define MDB_USE_HASH 1
161 #define MDB_PIDLOCK 0
162 #define pthread_t DWORD
163 #define pthread_mutex_t HANDLE
164 #define pthread_key_t DWORD
165 #define pthread_self() GetCurrentThreadId()
166 #define pthread_key_create(x,y) \
167 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
168 #define pthread_key_delete(x) TlsFree(x)
169 #define pthread_getspecific(x) TlsGetValue(x)
170 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
171 #define pthread_mutex_unlock(x) ReleaseMutex(x)
172 #define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE)
173 #define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex)
174 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex)
175 #define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex)
176 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex)
177 #define getpid() GetCurrentProcessId()
178 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
179 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
180 #define ErrCode() GetLastError()
181 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
182 #define close(fd) (CloseHandle(fd) ? 0 : -1)
183 #define munmap(ptr,len) UnmapViewOfFile(ptr)
184 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
185 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
187 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
192 #define Z "z" /**< printf format modifier for size_t */
194 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
195 #define MDB_PIDLOCK 1
197 #ifdef MDB_USE_POSIX_SEM
199 #define LOCK_MUTEX_R(env) mdb_sem_wait((env)->me_rmutex)
200 #define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex)
201 #define LOCK_MUTEX_W(env) mdb_sem_wait((env)->me_wmutex)
202 #define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex)
205 mdb_sem_wait(sem_t *sem)
208 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
213 /** Lock the reader mutex.
215 #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex)
216 /** Unlock the reader mutex.
218 #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
220 /** Lock the writer mutex.
221 * Only a single write transaction is allowed at a time. Other writers
222 * will block waiting for this mutex.
224 #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
225 /** Unlock the writer mutex.
227 #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
228 #endif /* MDB_USE_POSIX_SEM */
230 /** Get the error code for the last failed system function.
232 #define ErrCode() errno
234 /** An abstraction for a file handle.
235 * On POSIX systems file handles are small integers. On Windows
236 * they're opaque pointers.
240 /** A value for an invalid file handle.
241 * Mainly used to initialize file variables and signify that they are
244 #define INVALID_HANDLE_VALUE (-1)
246 /** Get the size of a memory page for the system.
247 * This is the basic size that the platform's memory manager uses, and is
248 * fundamental to the use of memory-mapped files.
250 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
253 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
256 #define MNAME_LEN (sizeof(pthread_mutex_t))
262 /** A flag for opening a file and requesting synchronous data writes.
263 * This is only used when writing a meta page. It's not strictly needed;
264 * we could just do a normal write and then immediately perform a flush.
265 * But if this flag is available it saves us an extra system call.
267 * @note If O_DSYNC is undefined but exists in /usr/include,
268 * preferably set some compiler flag to get the definition.
269 * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
272 # define MDB_DSYNC O_DSYNC
276 /** Function for flushing the data of a file. Define this to fsync
277 * if fdatasync() is not supported.
279 #ifndef MDB_FDATASYNC
280 # define MDB_FDATASYNC fdatasync
284 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
295 /** A page number in the database.
296 * Note that 64 bit page numbers are overkill, since pages themselves
297 * already represent 12-13 bits of addressable memory, and the OS will
298 * always limit applications to a maximum of 63 bits of address space.
300 * @note In the #MDB_node structure, we only store 48 bits of this value,
301 * which thus limits us to only 60 bits of addressable data.
303 typedef MDB_ID pgno_t;
305 /** A transaction ID.
306 * See struct MDB_txn.mt_txnid for details.
308 typedef MDB_ID txnid_t;
310 /** @defgroup debug Debug Macros
314 /** Enable debug output. Needs variable argument macros (a C99 feature).
315 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
316 * read from and written to the database (used for free space management).
322 static int mdb_debug;
323 static txnid_t mdb_debug_start;
325 /** Print a debug message with printf formatting.
326 * Requires double parenthesis around 2 or more args.
328 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
329 # define DPRINTF0(fmt, ...) \
330 fprintf(stderr, "%s:%d " fmt "\n", __func__, __LINE__, __VA_ARGS__)
332 # define DPRINTF(args) ((void) 0)
334 /** Print a debug string.
335 * The string is printed literally, with no format processing.
337 #define DPUTS(arg) DPRINTF(("%s", arg))
338 /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
340 (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
343 /** @brief The maximum size of a database page.
345 * This is 32k, since it must fit in #MDB_page.#mp_upper.
347 * LMDB will use database pages < OS pages if needed.
348 * That causes more I/O in write transactions: The OS must
349 * know (read) the whole page before writing a partial page.
351 * Note that we don't currently support Huge pages. On Linux,
352 * regular data files cannot use Huge pages, and in general
353 * Huge pages aren't actually pageable. We rely on the OS
354 * demand-pager to read our data and page it out when memory
355 * pressure from other processes is high. So until OSs have
356 * actual paging support for Huge pages, they're not viable.
358 #define MAX_PAGESIZE 0x8000
360 /** The minimum number of keys required in a database page.
361 * Setting this to a larger value will place a smaller bound on the
362 * maximum size of a data item. Data items larger than this size will
363 * be pushed into overflow pages instead of being stored directly in
364 * the B-tree node. This value used to default to 4. With a page size
365 * of 4096 bytes that meant that any item larger than 1024 bytes would
366 * go into an overflow page. That also meant that on average 2-3KB of
367 * each overflow page was wasted space. The value cannot be lower than
368 * 2 because then there would no longer be a tree structure. With this
369 * value, items larger than 2KB will go into overflow pages, and on
370 * average only 1KB will be wasted.
372 #define MDB_MINKEYS 2
374 /** A stamp that identifies a file as an MDB file.
375 * There's nothing special about this value other than that it is easily
376 * recognizable, and it will reflect any byte order mismatches.
378 #define MDB_MAGIC 0xBEEFC0DE
380 /** The version number for a database's datafile format. */
381 #define MDB_DATA_VERSION 1
382 /** The version number for a database's lockfile format. */
383 #define MDB_LOCK_VERSION 1
385 /** @brief The maximum size of a key in the database.
387 * The library rejects bigger keys, and cannot deal with records
388 * with bigger keys stored by a library with bigger max keysize.
390 * We require that keys all fit onto a regular page. This limit
391 * could be raised a bit further if needed; to something just
392 * under (page size / #MDB_MINKEYS / 3).
394 * Note that data items in an #MDB_DUPSORT database are actually keys
395 * of a subDB, so they're also limited to this size.
397 #ifndef MDB_MAXKEYSIZE
398 #define MDB_MAXKEYSIZE 511
401 /** @brief The maximum size of a data item.
403 * We only store a 32 bit value for node sizes.
405 #define MAXDATASIZE 0xffffffffUL
410 * This is used for printing a hex dump of a key's contents.
412 #define DKBUF char kbuf[(MDB_MAXKEYSIZE*2+1)]
413 /** Display a key in hex.
415 * Invoke a function to display a key in hex.
417 #define DKEY(x) mdb_dkey(x, kbuf)
423 /** An invalid page number.
424 * Mainly used to denote an empty tree.
426 #define P_INVALID (~(pgno_t)0)
428 /** Test if the flags \b f are set in a flag word \b w. */
429 #define F_ISSET(w, f) (((w) & (f)) == (f))
431 /** Used for offsets within a single page.
432 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
435 typedef uint16_t indx_t;
437 /** Default size of memory map.
438 * This is certainly too small for any actual applications. Apps should always set
439 * the size explicitly using #mdb_env_set_mapsize().
441 #define DEFAULT_MAPSIZE 1048576
443 /** @defgroup readers Reader Lock Table
444 * Readers don't acquire any locks for their data access. Instead, they
445 * simply record their transaction ID in the reader table. The reader
446 * mutex is needed just to find an empty slot in the reader table. The
447 * slot's address is saved in thread-specific data so that subsequent read
448 * transactions started by the same thread need no further locking to proceed.
450 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
452 * No reader table is used if the database is on a read-only filesystem, or
453 * if #MDB_NOLOCK is set.
455 * Since the database uses multi-version concurrency control, readers don't
456 * actually need any locking. This table is used to keep track of which
457 * readers are using data from which old transactions, so that we'll know
458 * when a particular old transaction is no longer in use. Old transactions
459 * that have discarded any data pages can then have those pages reclaimed
460 * for use by a later write transaction.
462 * The lock table is constructed such that reader slots are aligned with the
463 * processor's cache line size. Any slot is only ever used by one thread.
464 * This alignment guarantees that there will be no contention or cache
465 * thrashing as threads update their own slot info, and also eliminates
466 * any need for locking when accessing a slot.
468 * A writer thread will scan every slot in the table to determine the oldest
469 * outstanding reader transaction. Any freed pages older than this will be
470 * reclaimed by the writer. The writer doesn't use any locks when scanning
471 * this table. This means that there's no guarantee that the writer will
472 * see the most up-to-date reader info, but that's not required for correct
473 * operation - all we need is to know the upper bound on the oldest reader,
474 * we don't care at all about the newest reader. So the only consequence of
475 * reading stale information here is that old pages might hang around a
476 * while longer before being reclaimed. That's actually good anyway, because
477 * the longer we delay reclaiming old pages, the more likely it is that a
478 * string of contiguous pages can be found after coalescing old pages from
479 * many old transactions together.
482 /** Number of slots in the reader table.
483 * This value was chosen somewhat arbitrarily. 126 readers plus a
484 * couple mutexes fit exactly into 8KB on my development machine.
485 * Applications should set the table size using #mdb_env_set_maxreaders().
487 #define DEFAULT_READERS 126
489 /** The size of a CPU cache line in bytes. We want our lock structures
490 * aligned to this size to avoid false cache line sharing in the
492 * This value works for most CPUs. For Itanium this should be 128.
498 /** The information we store in a single slot of the reader table.
499 * In addition to a transaction ID, we also record the process and
500 * thread ID that owns a slot, so that we can detect stale information,
501 * e.g. threads or processes that went away without cleaning up.
502 * @note We currently don't check for stale records. We simply re-init
503 * the table when we know that we're the only process opening the
506 typedef struct MDB_rxbody {
507 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
508 * Multiple readers that start at the same time will probably have the
509 * same ID here. Again, it's not important to exclude them from
510 * anything; all we need to know is which version of the DB they
511 * started from so we can avoid overwriting any data used in that
512 * particular version.
515 /** The process ID of the process owning this reader txn. */
517 /** The thread ID of the thread owning this txn. */
521 /** The actual reader record, with cacheline padding. */
522 typedef struct MDB_reader {
525 /** shorthand for mrb_txnid */
526 #define mr_txnid mru.mrx.mrb_txnid
527 #define mr_pid mru.mrx.mrb_pid
528 #define mr_tid mru.mrx.mrb_tid
529 /** cache line alignment */
530 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
534 /** The header for the reader table.
535 * The table resides in a memory-mapped file. (This is a different file
536 * than is used for the main database.)
538 * For POSIX the actual mutexes reside in the shared memory of this
539 * mapped file. On Windows, mutexes are named objects allocated by the
540 * kernel; we store the mutex names in this mapped file so that other
541 * processes can grab them. This same approach is also used on
542 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
543 * process-shared POSIX mutexes. For these cases where a named object
544 * is used, the object name is derived from a 64 bit FNV hash of the
545 * environment pathname. As such, naming collisions are extremely
546 * unlikely. If a collision occurs, the results are unpredictable.
548 typedef struct MDB_txbody {
549 /** Stamp identifying this as an MDB file. It must be set
552 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
554 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
555 char mtb_rmname[MNAME_LEN];
557 /** Mutex protecting access to this table.
558 * This is the reader lock that #LOCK_MUTEX_R acquires.
560 pthread_mutex_t mtb_mutex;
562 /** The ID of the last transaction committed to the database.
563 * This is recorded here only for convenience; the value can always
564 * be determined by reading the main database meta pages.
567 /** The number of slots that have been used in the reader table.
568 * This always records the maximum count, it is not decremented
569 * when readers release their slots.
571 unsigned mtb_numreaders;
574 /** The actual reader table definition. */
575 typedef struct MDB_txninfo {
578 #define mti_magic mt1.mtb.mtb_magic
579 #define mti_format mt1.mtb.mtb_format
580 #define mti_mutex mt1.mtb.mtb_mutex
581 #define mti_rmname mt1.mtb.mtb_rmname
582 #define mti_txnid mt1.mtb.mtb_txnid
583 #define mti_numreaders mt1.mtb.mtb_numreaders
584 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
587 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
588 char mt2_wmname[MNAME_LEN];
589 #define mti_wmname mt2.mt2_wmname
591 pthread_mutex_t mt2_wmutex;
592 #define mti_wmutex mt2.mt2_wmutex
594 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
596 MDB_reader mti_readers[1];
599 /** Lockfile format signature: version, features and field layout */
600 #define MDB_LOCK_FORMAT \
602 ((MDB_LOCK_VERSION) \
603 /* Flags which describe functionality */ \
604 + (((MDB_PIDLOCK) != 0) << 16)))
607 /** Common header for all page types.
608 * Overflow records occupy a number of contiguous pages with no
609 * headers on any page after the first.
611 typedef struct MDB_page {
612 #define mp_pgno mp_p.p_pgno
613 #define mp_next mp_p.p_next
615 pgno_t p_pgno; /**< page number */
616 void * p_next; /**< for in-memory list of freed structs */
619 /** @defgroup mdb_page Page Flags
621 * Flags for the page headers.
624 #define P_BRANCH 0x01 /**< branch page */
625 #define P_LEAF 0x02 /**< leaf page */
626 #define P_OVERFLOW 0x04 /**< overflow page */
627 #define P_META 0x08 /**< meta page */
628 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
629 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
630 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
631 #define P_KEEP 0x8000 /**< leave this page alone during spill */
633 uint16_t mp_flags; /**< @ref mdb_page */
634 #define mp_lower mp_pb.pb.pb_lower
635 #define mp_upper mp_pb.pb.pb_upper
636 #define mp_pages mp_pb.pb_pages
639 indx_t pb_lower; /**< lower bound of free space */
640 indx_t pb_upper; /**< upper bound of free space */
642 uint32_t pb_pages; /**< number of overflow pages */
644 indx_t mp_ptrs[1]; /**< dynamic size */
647 /** Size of the page header, excluding dynamic data at the end */
648 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
650 /** Address of first usable data byte in a page, after the header */
651 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
653 /** Number of nodes on a page */
654 #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
656 /** The amount of space remaining in the page */
657 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
659 /** The percentage of space used in the page, in tenths of a percent. */
660 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
661 ((env)->me_psize - PAGEHDRSZ))
662 /** The minimum page fill factor, in tenths of a percent.
663 * Pages emptier than this are candidates for merging.
665 #define FILL_THRESHOLD 250
667 /** Test if a page is a leaf page */
668 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
669 /** Test if a page is a LEAF2 page */
670 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
671 /** Test if a page is a branch page */
672 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
673 /** Test if a page is an overflow page */
674 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
675 /** Test if a page is a sub page */
676 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
678 /** The number of overflow pages needed to store the given size. */
679 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
681 /** Header for a single key/data pair within a page.
682 * We guarantee 2-byte alignment for nodes.
684 typedef struct MDB_node {
685 /** lo and hi are used for data size on leaf nodes and for
686 * child pgno on branch nodes. On 64 bit platforms, flags
687 * is also used for pgno. (Branch nodes have no flags).
688 * They are in host byte order in case that lets some
689 * accesses be optimized into a 32-bit word access.
691 #define mn_lo mn_offset[BYTE_ORDER!=LITTLE_ENDIAN]
692 #define mn_hi mn_offset[BYTE_ORDER==LITTLE_ENDIAN] /**< part of dsize or pgno */
693 unsigned short mn_offset[2]; /**< storage for #mn_lo and #mn_hi */
694 /** @defgroup mdb_node Node Flags
696 * Flags for node headers.
699 #define F_BIGDATA 0x01 /**< data put on overflow page */
700 #define F_SUBDATA 0x02 /**< data is a sub-database */
701 #define F_DUPDATA 0x04 /**< data has duplicates */
703 /** valid flags for #mdb_node_add() */
704 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
707 unsigned short mn_flags; /**< @ref mdb_node */
708 unsigned short mn_ksize; /**< key size */
709 char mn_data[1]; /**< key and data are appended here */
712 /** Size of the node header, excluding dynamic data at the end */
713 #define NODESIZE offsetof(MDB_node, mn_data)
715 /** Bit position of top word in page number, for shifting mn_flags */
716 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
718 /** Size of a node in a branch page with a given key.
719 * This is just the node header plus the key, there is no data.
721 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
723 /** Size of a node in a leaf page with a given key and data.
724 * This is node header plus key plus data size.
726 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
728 /** Address of node \b i in page \b p */
729 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
731 /** Address of the key for the node */
732 #define NODEKEY(node) (void *)((node)->mn_data)
734 /** Address of the data for a node */
735 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
737 /** Get the page number pointed to by a branch node */
738 #define NODEPGNO(node) \
739 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
740 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
741 /** Set the page number in a branch node */
742 #define SETPGNO(node,pgno) do { \
743 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
744 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
746 /** Get the size of the data in a leaf node */
747 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
748 /** Set the size of the data for a leaf node */
749 #define SETDSZ(node,size) do { \
750 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
751 /** The size of a key in a node */
752 #define NODEKSZ(node) ((node)->mn_ksize)
754 /** Copy a page number from src to dst */
756 #define COPY_PGNO(dst,src) dst = src
758 #if SIZE_MAX > 4294967295UL
759 #define COPY_PGNO(dst,src) do { \
760 unsigned short *s, *d; \
761 s = (unsigned short *)&(src); \
762 d = (unsigned short *)&(dst); \
769 #define COPY_PGNO(dst,src) do { \
770 unsigned short *s, *d; \
771 s = (unsigned short *)&(src); \
772 d = (unsigned short *)&(dst); \
778 /** The address of a key in a LEAF2 page.
779 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
780 * There are no node headers, keys are stored contiguously.
782 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
784 /** Set the \b node's key into \b keyptr, if requested. */
785 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
786 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
788 /** Set the \b node's key into \b key. */
789 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
791 /** Information about a single database in the environment. */
792 typedef struct MDB_db {
793 uint32_t md_pad; /**< also ksize for LEAF2 pages */
794 uint16_t md_flags; /**< @ref mdb_dbi_open */
795 uint16_t md_depth; /**< depth of this tree */
796 pgno_t md_branch_pages; /**< number of internal pages */
797 pgno_t md_leaf_pages; /**< number of leaf pages */
798 pgno_t md_overflow_pages; /**< number of overflow pages */
799 size_t md_entries; /**< number of data items */
800 pgno_t md_root; /**< the root page of this tree */
803 /** mdb_dbi_open flags */
804 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
805 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
806 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
807 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
809 /** Handle for the DB used to track free pages. */
811 /** Handle for the default DB. */
814 /** Meta page content.
815 * A meta page is the start point for accessing a database snapshot.
816 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
818 typedef struct MDB_meta {
819 /** Stamp identifying this as an MDB file. It must be set
822 /** Version number of this lock file. Must be set to #MDB_DATA_VERSION. */
824 void *mm_address; /**< address for fixed mapping */
825 size_t mm_mapsize; /**< size of mmap region */
826 MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */
827 /** The size of pages used in this DB */
828 #define mm_psize mm_dbs[0].md_pad
829 /** Any persistent environment flags. @ref mdb_env */
830 #define mm_flags mm_dbs[0].md_flags
831 pgno_t mm_last_pg; /**< last used page in file */
832 txnid_t mm_txnid; /**< txnid that committed this page */
835 /** Buffer for a stack-allocated meta page.
836 * The members define size and alignment, and silence type
837 * aliasing warnings. They are not used directly; that could
838 * mean incorrectly using several union members in parallel.
840 typedef union MDB_metabuf {
843 char mm_pad[PAGEHDRSZ];
848 /** Auxiliary DB info.
849 * The information here is mostly static/read-only. There is
850 * only a single copy of this record in the environment.
852 typedef struct MDB_dbx {
853 MDB_val md_name; /**< name of the database */
854 MDB_cmp_func *md_cmp; /**< function for comparing keys */
855 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
856 MDB_rel_func *md_rel; /**< user relocate function */
857 void *md_relctx; /**< user-provided context for md_rel */
860 /** A database transaction.
861 * Every operation requires a transaction handle.
864 MDB_txn *mt_parent; /**< parent of a nested txn */
865 MDB_txn *mt_child; /**< nested txn under this txn */
866 pgno_t mt_next_pgno; /**< next unallocated page */
867 /** The ID of this transaction. IDs are integers incrementing from 1.
868 * Only committed write transactions increment the ID. If a transaction
869 * aborts, the ID may be re-used by the next writer.
872 MDB_env *mt_env; /**< the DB environment */
873 /** The list of pages that became unused during this transaction.
876 /** The sorted list of dirty pages we temporarily wrote to disk
877 * because the dirty list was full. page numbers in here are
878 * shifted left by 1, deleted slots have the LSB set.
880 MDB_IDL mt_spill_pgs;
882 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
884 /** For read txns: This thread/txn's reader table slot, or NULL. */
887 /** Array of records for each DB known in the environment. */
889 /** Array of MDB_db records for each known DB */
891 /** @defgroup mt_dbflag Transaction DB Flags
895 #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
896 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
897 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
898 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
900 /** In write txns, array of cursors for each DB */
901 MDB_cursor **mt_cursors;
902 /** Array of flags for each DB */
903 unsigned char *mt_dbflags;
904 /** Number of DB records in use. This number only ever increments;
905 * we don't decrement it when individual DB handles are closed.
909 /** @defgroup mdb_txn Transaction Flags
913 #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */
914 #define MDB_TXN_ERROR 0x02 /**< an error has occurred */
915 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
916 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
918 unsigned int mt_flags; /**< @ref mdb_txn */
919 /** dirty_list room: Array size - #dirty pages visible to this txn.
920 * Includes ancestor txns' dirty pages not hidden by other txns'
921 * dirty/spilled pages. Thus commit(nested txn) has room to merge
922 * dirty_list into mt_parent after freeing hidden mt_parent pages.
924 unsigned int mt_dirty_room;
927 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
928 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
929 * raise this on a 64 bit machine.
931 #define CURSOR_STACK 32
935 /** Cursors are used for all DB operations.
936 * A cursor holds a path of (page pointer, key index) from the DB
937 * root to a position in the DB, plus other state. #MDB_DUPSORT
938 * cursors include an xcursor to the current data item. Write txns
939 * track their cursors and keep them up to date when data moves.
940 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
941 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
944 /** Next cursor on this DB in this txn */
946 /** Backup of the original cursor if this cursor is a shadow */
947 MDB_cursor *mc_backup;
948 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
949 struct MDB_xcursor *mc_xcursor;
950 /** The transaction that owns this cursor */
952 /** The database handle this cursor operates on */
954 /** The database record for this cursor */
956 /** The database auxiliary record for this cursor */
958 /** The @ref mt_dbflag for this database */
959 unsigned char *mc_dbflag;
960 unsigned short mc_snum; /**< number of pushed pages */
961 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
962 /** @defgroup mdb_cursor Cursor Flags
964 * Cursor state flags.
967 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
968 #define C_EOF 0x02 /**< No more data */
969 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
970 #define C_DEL 0x08 /**< last op was a cursor_del */
971 #define C_SPLITTING 0x20 /**< Cursor is in page_split */
972 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
974 unsigned int mc_flags; /**< @ref mdb_cursor */
975 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
976 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
979 /** Context for sorted-dup records.
980 * We could have gone to a fully recursive design, with arbitrarily
981 * deep nesting of sub-databases. But for now we only handle these
982 * levels - main DB, optional sub-DB, sorted-duplicate DB.
984 typedef struct MDB_xcursor {
985 /** A sub-cursor for traversing the Dup DB */
986 MDB_cursor mx_cursor;
987 /** The database record for this Dup DB */
989 /** The auxiliary DB record for this Dup DB */
991 /** The @ref mt_dbflag for this Dup DB */
992 unsigned char mx_dbflag;
995 /** State of FreeDB old pages, stored in the MDB_env */
996 typedef struct MDB_pgstate {
997 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
998 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
1001 /** The database environment. */
1003 HANDLE me_fd; /**< The main data file */
1004 HANDLE me_lfd; /**< The lock file */
1005 HANDLE me_mfd; /**< just for writing the meta pages */
1006 /** Failed to update the meta page. Probably an I/O error. */
1007 #define MDB_FATAL_ERROR 0x80000000U
1008 /** Some fields are initialized. */
1009 #define MDB_ENV_ACTIVE 0x20000000U
1010 /** me_txkey is set */
1011 #define MDB_ENV_TXKEY 0x10000000U
1012 /** Have liveness lock in reader table */
1013 #define MDB_LIVE_READER 0x08000000U
1014 uint32_t me_flags; /**< @ref mdb_env */
1015 unsigned int me_psize; /**< DB page size, inited from me_os_psize */
1016 unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
1017 unsigned int me_maxreaders; /**< size of the reader table */
1018 unsigned int me_numreaders; /**< max numreaders set by this env */
1019 MDB_dbi me_numdbs; /**< number of DBs opened */
1020 MDB_dbi me_maxdbs; /**< size of the DB table */
1021 MDB_PID_T me_pid; /**< process ID of this env */
1022 char *me_path; /**< path to the DB files */
1023 char *me_map; /**< the memory map of the data file */
1024 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1025 MDB_meta *me_metas[2]; /**< pointers to the two meta pages */
1026 void *me_pbuf; /**< scratch area for DUPSORT put() */
1027 MDB_txn *me_txn; /**< current write transaction */
1028 size_t me_mapsize; /**< size of the data memory map */
1029 off_t me_size; /**< current file size */
1030 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1031 MDB_dbx *me_dbxs; /**< array of static DB info */
1032 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1033 pthread_key_t me_txkey; /**< thread-key for readers */
1034 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1035 # define me_pglast me_pgstate.mf_pglast
1036 # define me_pghead me_pgstate.mf_pghead
1037 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1038 /** IDL of pages that became unused in a write txn */
1039 MDB_IDL me_free_pgs;
1040 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1041 MDB_ID2L me_dirty_list;
1042 /** Max number of freelist items that can fit in a single overflow page */
1044 /** Max size of a node on a page */
1045 unsigned int me_nodemax;
1047 int me_pidquery; /**< Used in OpenProcess */
1048 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */
1050 #elif defined(MDB_USE_POSIX_SEM)
1051 sem_t *me_rmutex; /* Shared mutexes are not supported */
1056 /** Nested transaction */
1057 typedef struct MDB_ntxn {
1058 MDB_txn mnt_txn; /**< the transaction */
1059 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1062 /** max number of pages to commit in one writev() call */
1063 #define MDB_COMMIT_PAGES 64
1064 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1065 #undef MDB_COMMIT_PAGES
1066 #define MDB_COMMIT_PAGES IOV_MAX
1069 /* max bytes to write in one call */
1070 #define MAX_WRITE (0x80000000U >> (sizeof(ssize_t) == 4))
1072 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1073 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1074 static int mdb_page_touch(MDB_cursor *mc);
1076 static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
1077 static int mdb_page_search_root(MDB_cursor *mc,
1078 MDB_val *key, int modify);
1079 #define MDB_PS_MODIFY 1
1080 #define MDB_PS_ROOTONLY 2
1081 #define MDB_PS_FIRST 4
1082 #define MDB_PS_LAST 8
1083 static int mdb_page_search(MDB_cursor *mc,
1084 MDB_val *key, int flags);
1085 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1087 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1088 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1089 pgno_t newpgno, unsigned int nflags);
1091 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1092 static int mdb_env_pick_meta(const MDB_env *env);
1093 static int mdb_env_write_meta(MDB_txn *txn);
1094 #if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
1095 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1097 static void mdb_env_close0(MDB_env *env, int excl);
1099 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1100 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1101 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1102 static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize);
1103 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1104 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
1105 static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
1106 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1107 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1109 static int mdb_rebalance(MDB_cursor *mc);
1110 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1112 static void mdb_cursor_pop(MDB_cursor *mc);
1113 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1115 static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf);
1116 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1117 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1118 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1119 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1121 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1122 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1124 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1125 static void mdb_xcursor_init0(MDB_cursor *mc);
1126 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1128 static int mdb_drop0(MDB_cursor *mc, int subs);
1129 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1132 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1136 static SECURITY_DESCRIPTOR mdb_null_sd;
1137 static SECURITY_ATTRIBUTES mdb_all_sa;
1138 static int mdb_sec_inited;
1141 /** Return the library version info. */
1143 mdb_version(int *major, int *minor, int *patch)
1145 if (major) *major = MDB_VERSION_MAJOR;
1146 if (minor) *minor = MDB_VERSION_MINOR;
1147 if (patch) *patch = MDB_VERSION_PATCH;
1148 return MDB_VERSION_STRING;
1151 /** Table of descriptions for MDB @ref errors */
1152 static char *const mdb_errstr[] = {
1153 "MDB_KEYEXIST: Key/data pair already exists",
1154 "MDB_NOTFOUND: No matching key/data pair found",
1155 "MDB_PAGE_NOTFOUND: Requested page not found",
1156 "MDB_CORRUPTED: Located page was wrong type",
1157 "MDB_PANIC: Update of meta page failed",
1158 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1159 "MDB_INVALID: File is not an MDB file",
1160 "MDB_MAP_FULL: Environment mapsize limit reached",
1161 "MDB_DBS_FULL: Environment maxdbs limit reached",
1162 "MDB_READERS_FULL: Environment maxreaders limit reached",
1163 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1164 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1165 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1166 "MDB_PAGE_FULL: Internal error - page has no more space",
1167 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1168 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1169 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1170 "MDB_BAD_TXN: Transaction cannot recover - it must be aborted",
1171 "MDB_BAD_VALSIZE: Too big key/data, key is empty, or wrong DUPFIXED size",
1175 mdb_strerror(int err)
1179 return ("Successful return: 0");
1181 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1182 i = err - MDB_KEYEXIST;
1183 return mdb_errstr[i];
1186 return strerror(err);
1190 /** Display a key in hexadecimal and return the address of the result.
1191 * @param[in] key the key to display
1192 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1193 * @return The key in hexadecimal form.
1196 mdb_dkey(MDB_val *key, char *buf)
1199 unsigned char *c = key->mv_data;
1205 if (key->mv_size > MDB_MAXKEYSIZE)
1206 return "MDB_MAXKEYSIZE";
1207 /* may want to make this a dynamic check: if the key is mostly
1208 * printable characters, print it as-is instead of converting to hex.
1212 for (i=0; i<key->mv_size; i++)
1213 ptr += sprintf(ptr, "%02x", *c++);
1215 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1220 /** Display all the keys in the page. */
1222 mdb_page_list(MDB_page *mp)
1225 unsigned int i, nkeys, nsize;
1229 nkeys = NUMKEYS(mp);
1230 fprintf(stderr, "Page %"Z"u numkeys %d\n", mp->mp_pgno, nkeys);
1231 for (i=0; i<nkeys; i++) {
1232 node = NODEPTR(mp, i);
1233 key.mv_size = node->mn_ksize;
1234 key.mv_data = node->mn_data;
1235 nsize = NODESIZE + NODEKSZ(node) + sizeof(indx_t);
1236 if (IS_BRANCH(mp)) {
1237 fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
1240 if (F_ISSET(node->mn_flags, F_BIGDATA))
1241 nsize += sizeof(pgno_t);
1243 nsize += NODEDSZ(node);
1244 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1250 mdb_cursor_chk(MDB_cursor *mc)
1256 if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
1257 for (i=0; i<mc->mc_top; i++) {
1259 node = NODEPTR(mp, mc->mc_ki[i]);
1260 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1263 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1269 /** Count all the pages in each DB and in the freelist
1270 * and make sure it matches the actual number of pages
1273 static void mdb_audit(MDB_txn *txn)
1277 MDB_ID freecount, count;
1282 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1283 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1284 freecount += *(MDB_ID *)data.mv_data;
1287 for (i = 0; i<txn->mt_numdbs; i++) {
1289 mdb_cursor_init(&mc, txn, i, &mx);
1290 if (txn->mt_dbs[i].md_root == P_INVALID)
1292 count += txn->mt_dbs[i].md_branch_pages +
1293 txn->mt_dbs[i].md_leaf_pages +
1294 txn->mt_dbs[i].md_overflow_pages;
1295 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1296 mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1300 mp = mc.mc_pg[mc.mc_top];
1301 for (j=0; j<NUMKEYS(mp); j++) {
1302 MDB_node *leaf = NODEPTR(mp, j);
1303 if (leaf->mn_flags & F_SUBDATA) {
1305 memcpy(&db, NODEDATA(leaf), sizeof(db));
1306 count += db.md_branch_pages + db.md_leaf_pages +
1307 db.md_overflow_pages;
1311 while (mdb_cursor_sibling(&mc, 1) == 0);
1314 if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
1315 fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
1316 txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
1322 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1324 return txn->mt_dbxs[dbi].md_cmp(a, b);
1328 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1330 return txn->mt_dbxs[dbi].md_dcmp(a, b);
1333 /** Allocate memory for a page.
1334 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1337 mdb_page_malloc(MDB_txn *txn, unsigned num)
1339 MDB_env *env = txn->mt_env;
1340 MDB_page *ret = env->me_dpages;
1341 size_t psize = env->me_psize, sz = psize, off;
1342 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1343 * For a single page alloc, we init everything after the page header.
1344 * For multi-page, we init the final page; if the caller needed that
1345 * many pages they will be filling in at least up to the last page.
1349 VGMEMP_ALLOC(env, ret, sz);
1350 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1351 env->me_dpages = ret->mp_next;
1354 psize -= off = PAGEHDRSZ;
1359 if ((ret = malloc(sz)) != NULL) {
1360 if (!(env->me_flags & MDB_NOMEMINIT)) {
1361 memset((char *)ret + off, 0, psize);
1364 VGMEMP_ALLOC(env, ret, sz);
1369 /** Free a single page.
1370 * Saves single pages to a list, for future reuse.
1371 * (This is not used for multi-page overflow pages.)
1374 mdb_page_free(MDB_env *env, MDB_page *mp)
1376 mp->mp_next = env->me_dpages;
1377 VGMEMP_FREE(env, mp);
1378 env->me_dpages = mp;
1381 /** Free a dirty page */
1383 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1385 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1386 mdb_page_free(env, dp);
1388 /* large pages just get freed directly */
1389 VGMEMP_FREE(env, dp);
1394 /** Return all dirty pages to dpage list */
1396 mdb_dlist_free(MDB_txn *txn)
1398 MDB_env *env = txn->mt_env;
1399 MDB_ID2L dl = txn->mt_u.dirty_list;
1400 unsigned i, n = dl[0].mid;
1402 for (i = 1; i <= n; i++) {
1403 mdb_dpage_free(env, dl[i].mptr);
1408 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
1409 * @param[in] mc A cursor handle for the current operation.
1410 * @param[in] pflags Flags of the pages to update:
1411 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
1412 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
1413 * @return 0 on success, non-zero on failure.
1416 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
1418 enum { Mask = P_SUBP|P_DIRTY|P_KEEP };
1419 MDB_txn *txn = mc->mc_txn;
1425 int rc = MDB_SUCCESS, level;
1427 /* Mark pages seen by cursors */
1428 if (mc->mc_flags & C_UNTRACK)
1429 mc = NULL; /* will find mc in mt_cursors */
1430 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
1431 for (; mc; mc=mc->mc_next) {
1432 if (!(mc->mc_flags & C_INITIALIZED))
1434 for (m3 = mc;; m3 = &mx->mx_cursor) {
1436 for (j=0; j<m3->mc_snum; j++) {
1438 if ((mp->mp_flags & Mask) == pflags)
1439 mp->mp_flags ^= P_KEEP;
1441 mx = m3->mc_xcursor;
1442 /* Proceed to mx if it is at a sub-database */
1443 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
1445 if (! (mp && (mp->mp_flags & P_LEAF)))
1447 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
1448 if (!(leaf->mn_flags & F_SUBDATA))
1457 /* Mark dirty root pages */
1458 for (i=0; i<txn->mt_numdbs; i++) {
1459 if (txn->mt_dbflags[i] & DB_DIRTY) {
1460 pgno_t pgno = txn->mt_dbs[i].md_root;
1461 if (pgno == P_INVALID)
1463 if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
1465 if ((dp->mp_flags & Mask) == pflags && level <= 1)
1466 dp->mp_flags ^= P_KEEP;
1474 static int mdb_page_flush(MDB_txn *txn, int keep);
1476 /** Spill pages from the dirty list back to disk.
1477 * This is intended to prevent running into #MDB_TXN_FULL situations,
1478 * but note that they may still occur in a few cases:
1479 * 1) our estimate of the txn size could be too small. Currently this
1480 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
1481 * 2) child txns may run out of space if their parents dirtied a
1482 * lot of pages and never spilled them. TODO: we probably should do
1483 * a preemptive spill during #mdb_txn_begin() of a child txn, if
1484 * the parent's dirty_room is below a given threshold.
1486 * Otherwise, if not using nested txns, it is expected that apps will
1487 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
1488 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
1489 * If the txn never references them again, they can be left alone.
1490 * If the txn only reads them, they can be used without any fuss.
1491 * If the txn writes them again, they can be dirtied immediately without
1492 * going thru all of the work of #mdb_page_touch(). Such references are
1493 * handled by #mdb_page_unspill().
1495 * Also note, we never spill DB root pages, nor pages of active cursors,
1496 * because we'll need these back again soon anyway. And in nested txns,
1497 * we can't spill a page in a child txn if it was already spilled in a
1498 * parent txn. That would alter the parent txns' data even though
1499 * the child hasn't committed yet, and we'd have no way to undo it if
1500 * the child aborted.
1502 * @param[in] m0 cursor A cursor handle identifying the transaction and
1503 * database for which we are checking space.
1504 * @param[in] key For a put operation, the key being stored.
1505 * @param[in] data For a put operation, the data being stored.
1506 * @return 0 on success, non-zero on failure.
1509 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
1511 MDB_txn *txn = m0->mc_txn;
1513 MDB_ID2L dl = txn->mt_u.dirty_list;
1514 unsigned int i, j, need;
1517 if (m0->mc_flags & C_SUB)
1520 /* Estimate how much space this op will take */
1521 i = m0->mc_db->md_depth;
1522 /* Named DBs also dirty the main DB */
1523 if (m0->mc_dbi > MAIN_DBI)
1524 i += txn->mt_dbs[MAIN_DBI].md_depth;
1525 /* For puts, roughly factor in the key+data size */
1527 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
1528 i += i; /* double it for good measure */
1531 if (txn->mt_dirty_room > i)
1534 if (!txn->mt_spill_pgs) {
1535 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
1536 if (!txn->mt_spill_pgs)
1539 /* purge deleted slots */
1540 MDB_IDL sl = txn->mt_spill_pgs;
1541 unsigned int num = sl[0];
1543 for (i=1; i<=num; i++) {
1550 /* Preserve pages which may soon be dirtied again */
1551 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
1554 /* Less aggressive spill - we originally spilled the entire dirty list,
1555 * with a few exceptions for cursor pages and DB root pages. But this
1556 * turns out to be a lot of wasted effort because in a large txn many
1557 * of those pages will need to be used again. So now we spill only 1/8th
1558 * of the dirty pages. Testing revealed this to be a good tradeoff,
1559 * better than 1/2, 1/4, or 1/10.
1561 if (need < MDB_IDL_UM_MAX / 8)
1562 need = MDB_IDL_UM_MAX / 8;
1564 /* Save the page IDs of all the pages we're flushing */
1565 /* flush from the tail forward, this saves a lot of shifting later on. */
1566 for (i=dl[0].mid; i && need; i--) {
1567 MDB_ID pn = dl[i].mid << 1;
1569 if (dp->mp_flags & P_KEEP)
1571 /* Can't spill twice, make sure it's not already in a parent's
1574 if (txn->mt_parent) {
1576 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
1577 if (tx2->mt_spill_pgs) {
1578 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
1579 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
1580 dp->mp_flags |= P_KEEP;
1588 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
1592 mdb_midl_sort(txn->mt_spill_pgs);
1594 /* Flush the spilled part of dirty list */
1595 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
1598 /* Reset any dirty pages we kept that page_flush didn't see */
1599 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
1602 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
1606 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
1608 mdb_find_oldest(MDB_txn *txn)
1611 txnid_t mr, oldest = txn->mt_txnid - 1;
1612 if (txn->mt_env->me_txns) {
1613 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
1614 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
1625 /** Add a page to the txn's dirty list */
1627 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
1630 int (*insert)(MDB_ID2L, MDB_ID2 *);
1632 if (txn->mt_env->me_flags & MDB_WRITEMAP) {
1633 insert = mdb_mid2l_append;
1635 insert = mdb_mid2l_insert;
1637 mid.mid = mp->mp_pgno;
1639 insert(txn->mt_u.dirty_list, &mid);
1640 txn->mt_dirty_room--;
1643 /** Allocate page numbers and memory for writing. Maintain me_pglast,
1644 * me_pghead and mt_next_pgno.
1646 * If there are free pages available from older transactions, they
1647 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
1648 * Do not modify the freedB, just merge freeDB records into me_pghead[]
1649 * and move me_pglast to say which records were consumed. Only this
1650 * function can create me_pghead and move me_pglast/mt_next_pgno.
1651 * @param[in] mc cursor A cursor handle identifying the transaction and
1652 * database for which we are allocating.
1653 * @param[in] num the number of pages to allocate.
1654 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
1655 * will always be satisfied by a single contiguous chunk of memory.
1656 * @return 0 on success, non-zero on failure.
1659 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
1661 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
1662 /* Get at most <Max_retries> more freeDB records once me_pghead
1663 * has enough pages. If not enough, use new pages from the map.
1664 * If <Paranoid> and mc is updating the freeDB, only get new
1665 * records if me_pghead is empty. Then the freelist cannot play
1666 * catch-up with itself by growing while trying to save it.
1668 enum { Paranoid = 1, Max_retries = 500 };
1670 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
1672 int rc, n2 = num-1, retry = Max_retries;
1673 MDB_txn *txn = mc->mc_txn;
1674 MDB_env *env = txn->mt_env;
1675 pgno_t pgno, *mop = env->me_pghead;
1676 unsigned i, j, k, mop_len = mop ? mop[0] : 0;
1678 txnid_t oldest = 0, last;
1684 /* If our dirty list is already full, we can't do anything */
1685 if (txn->mt_dirty_room == 0)
1686 return MDB_TXN_FULL;
1688 for (op = MDB_FIRST;; op = MDB_NEXT) {
1691 pgno_t *idl, old_id, new_id;
1693 /* Seek a big enough contiguous page range. Prefer
1694 * pages at the tail, just truncating the list.
1696 if (mop_len >= (unsigned)num) {
1700 if (mop[i-n2] == pgno+n2)
1702 } while (--i >= (unsigned)num);
1703 if (Max_retries < INT_MAX && --retry < 0)
1707 if (op == MDB_FIRST) { /* 1st iteration */
1708 /* Prepare to fetch more and coalesce */
1709 oldest = mdb_find_oldest(txn);
1710 last = env->me_pglast;
1711 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
1714 key.mv_data = &last; /* will look up last+1 */
1715 key.mv_size = sizeof(last);
1717 if (Paranoid && mc->mc_dbi == FREE_DBI)
1720 if (Paranoid && retry < 0 && mop_len)
1724 /* Do not fetch more if the record will be too recent */
1727 rc = mdb_cursor_get(&m2, &key, NULL, op);
1729 if (rc == MDB_NOTFOUND)
1733 last = *(txnid_t*)key.mv_data;
1736 np = m2.mc_pg[m2.mc_top];
1737 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
1738 if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
1741 idl = (MDB_ID *) data.mv_data;
1744 if (!(env->me_pghead = mop = mdb_midl_alloc(i)))
1747 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
1749 mop = env->me_pghead;
1751 env->me_pglast = last;
1753 DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
1754 last, txn->mt_dbs[FREE_DBI].md_root, i));
1756 DPRINTF(("IDL %"Z"u", idl[k]));
1758 /* Merge in descending sorted order */
1761 mop[0] = (pgno_t)-1;
1765 for (; old_id < new_id; old_id = mop[--j])
1772 /* Use new pages from the map when nothing suitable in the freeDB */
1774 pgno = txn->mt_next_pgno;
1775 if (pgno + num >= env->me_maxpg) {
1776 DPUTS("DB size maxed out");
1777 return MDB_MAP_FULL;
1781 if (env->me_flags & MDB_WRITEMAP) {
1782 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
1784 if (!(np = mdb_page_malloc(txn, num)))
1788 mop[0] = mop_len -= num;
1789 /* Move any stragglers down */
1790 for (j = i-num; j < mop_len; )
1791 mop[++j] = mop[++i];
1793 txn->mt_next_pgno = pgno + num;
1796 mdb_page_dirty(txn, np);
1802 /** Copy the used portions of a non-overflow page.
1803 * @param[in] dst page to copy into
1804 * @param[in] src page to copy from
1805 * @param[in] psize size of a page
1808 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
1810 enum { Align = sizeof(pgno_t) };
1811 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
1813 /* If page isn't full, just copy the used portion. Adjust
1814 * alignment so memcpy may copy words instead of bytes.
1816 if ((unused &= -Align) && !IS_LEAF2(src)) {
1818 memcpy(dst, src, (lower + (Align-1)) & -Align);
1819 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
1822 memcpy(dst, src, psize - unused);
1826 /** Pull a page off the txn's spill list, if present.
1827 * If a page being referenced was spilled to disk in this txn, bring
1828 * it back and make it dirty/writable again.
1829 * @param[in] txn the transaction handle.
1830 * @param[in] mp the page being referenced.
1831 * @param[out] ret the writable page, if any. ret is unchanged if
1832 * mp wasn't spilled.
1835 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
1837 MDB_env *env = txn->mt_env;
1840 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
1842 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
1843 if (!tx2->mt_spill_pgs)
1845 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
1846 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
1849 if (txn->mt_dirty_room == 0)
1850 return MDB_TXN_FULL;
1851 if (IS_OVERFLOW(mp))
1855 if (env->me_flags & MDB_WRITEMAP) {
1858 np = mdb_page_malloc(txn, num);
1862 memcpy(np, mp, num * env->me_psize);
1864 mdb_page_copy(np, mp, env->me_psize);
1867 /* If in current txn, this page is no longer spilled.
1868 * If it happens to be the last page, truncate the spill list.
1869 * Otherwise mark it as deleted by setting the LSB.
1871 if (x == txn->mt_spill_pgs[0])
1872 txn->mt_spill_pgs[0]--;
1874 txn->mt_spill_pgs[x] |= 1;
1875 } /* otherwise, if belonging to a parent txn, the
1876 * page remains spilled until child commits
1879 mdb_page_dirty(txn, np);
1880 np->mp_flags |= P_DIRTY;
1888 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
1889 * @param[in] mc cursor pointing to the page to be touched
1890 * @return 0 on success, non-zero on failure.
1893 mdb_page_touch(MDB_cursor *mc)
1895 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
1896 MDB_txn *txn = mc->mc_txn;
1897 MDB_cursor *m2, *m3;
1901 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
1902 if (txn->mt_flags & MDB_TXN_SPILLS) {
1904 rc = mdb_page_unspill(txn, mp, &np);
1910 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
1911 (rc = mdb_page_alloc(mc, 1, &np)))
1914 DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
1915 mp->mp_pgno, pgno));
1916 assert(mp->mp_pgno != pgno);
1917 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
1918 /* Update the parent page, if any, to point to the new page */
1920 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
1921 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
1922 SETPGNO(node, pgno);
1924 mc->mc_db->md_root = pgno;
1926 } else if (txn->mt_parent && !IS_SUBP(mp)) {
1927 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
1929 /* If txn has a parent, make sure the page is in our
1933 unsigned x = mdb_mid2l_search(dl, pgno);
1934 if (x <= dl[0].mid && dl[x].mid == pgno) {
1935 if (mp != dl[x].mptr) { /* bad cursor? */
1936 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
1937 return MDB_CORRUPTED;
1942 assert(dl[0].mid < MDB_IDL_UM_MAX);
1944 np = mdb_page_malloc(txn, 1);
1949 mdb_mid2l_insert(dl, &mid);
1954 mdb_page_copy(np, mp, txn->mt_env->me_psize);
1956 np->mp_flags |= P_DIRTY;
1959 /* Adjust cursors pointing to mp */
1960 mc->mc_pg[mc->mc_top] = np;
1961 m2 = txn->mt_cursors[mc->mc_dbi];
1962 if (mc->mc_flags & C_SUB) {
1963 for (; m2; m2=m2->mc_next) {
1964 m3 = &m2->mc_xcursor->mx_cursor;
1965 if (m3->mc_snum < mc->mc_snum) continue;
1966 if (m3->mc_pg[mc->mc_top] == mp)
1967 m3->mc_pg[mc->mc_top] = np;
1970 for (; m2; m2=m2->mc_next) {
1971 if (m2->mc_snum < mc->mc_snum) continue;
1972 if (m2->mc_pg[mc->mc_top] == mp) {
1973 m2->mc_pg[mc->mc_top] = np;
1974 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
1975 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
1977 MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
1978 if (!(leaf->mn_flags & F_SUBDATA))
1979 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
1988 mdb_env_sync(MDB_env *env, int force)
1991 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
1992 if (env->me_flags & MDB_WRITEMAP) {
1993 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
1994 ? MS_ASYNC : MS_SYNC;
1995 if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
1998 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2002 if (MDB_FDATASYNC(env->me_fd))
2009 /** Back up parent txn's cursors, then grab the originals for tracking */
2011 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2013 MDB_cursor *mc, *bk;
2018 for (i = src->mt_numdbs; --i >= 0; ) {
2019 if ((mc = src->mt_cursors[i]) != NULL) {
2020 size = sizeof(MDB_cursor);
2022 size += sizeof(MDB_xcursor);
2023 for (; mc; mc = bk->mc_next) {
2029 mc->mc_db = &dst->mt_dbs[i];
2030 /* Kill pointers into src - and dst to reduce abuse: The
2031 * user may not use mc until dst ends. Otherwise we'd...
2033 mc->mc_txn = NULL; /* ...set this to dst */
2034 mc->mc_dbflag = NULL; /* ...and &dst->mt_dbflags[i] */
2035 if ((mx = mc->mc_xcursor) != NULL) {
2036 *(MDB_xcursor *)(bk+1) = *mx;
2037 mx->mx_cursor.mc_txn = NULL; /* ...and dst. */
2039 mc->mc_next = dst->mt_cursors[i];
2040 dst->mt_cursors[i] = mc;
2047 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2048 * @param[in] txn the transaction handle.
2049 * @param[in] merge true to keep changes to parent cursors, false to revert.
2050 * @return 0 on success, non-zero on failure.
2053 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2055 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2059 for (i = txn->mt_numdbs; --i >= 0; ) {
2060 for (mc = cursors[i]; mc; mc = next) {
2062 if ((bk = mc->mc_backup) != NULL) {
2064 /* Commit changes to parent txn */
2065 mc->mc_next = bk->mc_next;
2066 mc->mc_backup = bk->mc_backup;
2067 mc->mc_txn = bk->mc_txn;
2068 mc->mc_db = bk->mc_db;
2069 mc->mc_dbflag = bk->mc_dbflag;
2070 if ((mx = mc->mc_xcursor) != NULL)
2071 mx->mx_cursor.mc_txn = bk->mc_txn;
2073 /* Abort nested txn */
2075 if ((mx = mc->mc_xcursor) != NULL)
2076 *mx = *(MDB_xcursor *)(bk+1);
2080 /* Only malloced cursors are permanently tracked. */
2088 #define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn)
2091 mdb_txn_reset0(MDB_txn *txn, const char *act);
2093 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2099 Pidset = F_SETLK, Pidcheck = F_GETLK
2103 /** Set or check a pid lock. Set returns 0 on success.
2104 * Check returns 0 if the process is certainly dead, nonzero if it may
2105 * be alive (the lock exists or an error happened so we do not know).
2107 * On Windows Pidset is a no-op, we merely check for the existence
2108 * of the process with the given pid. On POSIX we use a single byte
2109 * lock on the lockfile, set at an offset equal to the pid.
2112 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2114 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2117 if (op == Pidcheck) {
2118 h = OpenProcess(env->me_pidquery, FALSE, pid);
2119 /* No documented "no such process" code, but other program use this: */
2121 return ErrCode() != ERROR_INVALID_PARAMETER;
2122 /* A process exists until all handles to it close. Has it exited? */
2123 ret = WaitForSingleObject(h, 0) != 0;
2130 struct flock lock_info;
2131 memset(&lock_info, 0, sizeof(lock_info));
2132 lock_info.l_type = F_WRLCK;
2133 lock_info.l_whence = SEEK_SET;
2134 lock_info.l_start = pid;
2135 lock_info.l_len = 1;
2136 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2137 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2139 } else if ((rc = ErrCode()) == EINTR) {
2147 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2148 * @param[in] txn the transaction handle to initialize
2149 * @return 0 on success, non-zero on failure.
2152 mdb_txn_renew0(MDB_txn *txn)
2154 MDB_env *env = txn->mt_env;
2155 MDB_txninfo *ti = env->me_txns;
2159 int rc, new_notls = 0;
2162 txn->mt_numdbs = env->me_numdbs;
2163 txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
2165 if (txn->mt_flags & MDB_TXN_RDONLY) {
2167 meta = env->me_metas[ mdb_env_pick_meta(env) ];
2168 txn->mt_txnid = meta->mm_txnid;
2169 txn->mt_u.reader = NULL;
2171 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2172 pthread_getspecific(env->me_txkey);
2174 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2175 return MDB_BAD_RSLOT;
2177 MDB_PID_T pid = env->me_pid;
2178 pthread_t tid = pthread_self();
2180 if (!(env->me_flags & MDB_LIVE_READER)) {
2181 rc = mdb_reader_pid(env, Pidset, pid);
2183 UNLOCK_MUTEX_R(env);
2186 env->me_flags |= MDB_LIVE_READER;
2190 nr = ti->mti_numreaders;
2191 for (i=0; i<nr; i++)
2192 if (ti->mti_readers[i].mr_pid == 0)
2194 if (i == env->me_maxreaders) {
2195 UNLOCK_MUTEX_R(env);
2196 return MDB_READERS_FULL;
2198 ti->mti_readers[i].mr_pid = pid;
2199 ti->mti_readers[i].mr_tid = tid;
2201 ti->mti_numreaders = ++nr;
2202 /* Save numreaders for un-mutexed mdb_env_close() */
2203 env->me_numreaders = nr;
2204 UNLOCK_MUTEX_R(env);
2206 r = &ti->mti_readers[i];
2207 new_notls = (env->me_flags & MDB_NOTLS);
2208 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2213 txn->mt_txnid = r->mr_txnid = ti->mti_txnid;
2214 txn->mt_u.reader = r;
2215 meta = env->me_metas[txn->mt_txnid & 1];
2221 txn->mt_txnid = ti->mti_txnid;
2222 meta = env->me_metas[txn->mt_txnid & 1];
2224 meta = env->me_metas[ mdb_env_pick_meta(env) ];
2225 txn->mt_txnid = meta->mm_txnid;
2229 if (txn->mt_txnid == mdb_debug_start)
2232 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2233 txn->mt_u.dirty_list = env->me_dirty_list;
2234 txn->mt_u.dirty_list[0].mid = 0;
2235 txn->mt_free_pgs = env->me_free_pgs;
2236 txn->mt_free_pgs[0] = 0;
2237 txn->mt_spill_pgs = NULL;
2241 /* Copy the DB info and flags */
2242 memcpy(txn->mt_dbs, meta->mm_dbs, 2 * sizeof(MDB_db));
2244 /* Moved to here to avoid a data race in read TXNs */
2245 txn->mt_next_pgno = meta->mm_last_pg+1;
2247 for (i=2; i<txn->mt_numdbs; i++) {
2248 x = env->me_dbflags[i];
2249 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2250 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0;
2252 txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID;
2254 if (env->me_maxpg < txn->mt_next_pgno) {
2255 mdb_txn_reset0(txn, "renew0-mapfail");
2257 txn->mt_u.reader->mr_pid = 0;
2258 txn->mt_u.reader = NULL;
2260 return MDB_MAP_RESIZED;
2267 mdb_txn_renew(MDB_txn *txn)
2271 if (!txn || txn->mt_dbxs) /* A reset txn has mt_dbxs==NULL */
2274 if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
2275 DPUTS("environment had fatal error, must shutdown!");
2279 rc = mdb_txn_renew0(txn);
2280 if (rc == MDB_SUCCESS) {
2281 DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2282 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2283 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
2289 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
2293 int rc, size, tsize = sizeof(MDB_txn);
2295 if (env->me_flags & MDB_FATAL_ERROR) {
2296 DPUTS("environment had fatal error, must shutdown!");
2299 if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
2302 /* Nested transactions: Max 1 child, write txns only, no writemap */
2303 if (parent->mt_child ||
2304 (flags & MDB_RDONLY) ||
2305 (parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) ||
2306 (env->me_flags & MDB_WRITEMAP))
2308 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
2310 tsize = sizeof(MDB_ntxn);
2312 size = tsize + env->me_maxdbs * (sizeof(MDB_db)+1);
2313 if (!(flags & MDB_RDONLY))
2314 size += env->me_maxdbs * sizeof(MDB_cursor *);
2316 if ((txn = calloc(1, size)) == NULL) {
2317 DPRINTF(("calloc: %s", strerror(ErrCode())));
2320 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
2321 if (flags & MDB_RDONLY) {
2322 txn->mt_flags |= MDB_TXN_RDONLY;
2323 txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
2325 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
2326 txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
2332 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
2333 if (!txn->mt_u.dirty_list ||
2334 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
2336 free(txn->mt_u.dirty_list);
2340 txn->mt_txnid = parent->mt_txnid;
2341 txn->mt_dirty_room = parent->mt_dirty_room;
2342 txn->mt_u.dirty_list[0].mid = 0;
2343 txn->mt_spill_pgs = NULL;
2344 txn->mt_next_pgno = parent->mt_next_pgno;
2345 parent->mt_child = txn;
2346 txn->mt_parent = parent;
2347 txn->mt_numdbs = parent->mt_numdbs;
2348 txn->mt_flags = parent->mt_flags;
2349 txn->mt_dbxs = parent->mt_dbxs;
2350 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2351 /* Copy parent's mt_dbflags, but clear DB_NEW */
2352 for (i=0; i<txn->mt_numdbs; i++)
2353 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
2355 ntxn = (MDB_ntxn *)txn;
2356 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
2357 if (env->me_pghead) {
2358 size = MDB_IDL_SIZEOF(env->me_pghead);
2359 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
2361 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
2366 rc = mdb_cursor_shadow(parent, txn);
2368 mdb_txn_reset0(txn, "beginchild-fail");
2370 rc = mdb_txn_renew0(txn);
2376 DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2377 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2378 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
2385 mdb_txn_env(MDB_txn *txn)
2387 if(!txn) return NULL;
2391 /** Export or close DBI handles opened in this txn. */
2393 mdb_dbis_update(MDB_txn *txn, int keep)
2396 MDB_dbi n = txn->mt_numdbs;
2397 MDB_env *env = txn->mt_env;
2398 unsigned char *tdbflags = txn->mt_dbflags;
2400 for (i = n; --i >= 2;) {
2401 if (tdbflags[i] & DB_NEW) {
2403 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
2405 char *ptr = env->me_dbxs[i].md_name.mv_data;
2406 env->me_dbxs[i].md_name.mv_data = NULL;
2407 env->me_dbxs[i].md_name.mv_size = 0;
2408 env->me_dbflags[i] = 0;
2413 if (keep && env->me_numdbs < n)
2417 /** Common code for #mdb_txn_reset() and #mdb_txn_abort().
2418 * May be called twice for readonly txns: First reset it, then abort.
2419 * @param[in] txn the transaction handle to reset
2420 * @param[in] act why the transaction is being reset
2423 mdb_txn_reset0(MDB_txn *txn, const char *act)
2425 MDB_env *env = txn->mt_env;
2427 /* Close any DBI handles opened in this txn */
2428 mdb_dbis_update(txn, 0);
2430 DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
2431 act, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2432 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
2434 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2435 if (txn->mt_u.reader) {
2436 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
2437 if (!(env->me_flags & MDB_NOTLS))
2438 txn->mt_u.reader = NULL; /* txn does not own reader */
2440 txn->mt_numdbs = 0; /* close nothing if called again */
2441 txn->mt_dbxs = NULL; /* mark txn as reset */
2443 mdb_cursors_close(txn, 0);
2445 if (!(env->me_flags & MDB_WRITEMAP)) {
2446 mdb_dlist_free(txn);
2448 mdb_midl_free(env->me_pghead);
2450 if (txn->mt_parent) {
2451 txn->mt_parent->mt_child = NULL;
2452 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
2453 mdb_midl_free(txn->mt_free_pgs);
2454 mdb_midl_free(txn->mt_spill_pgs);
2455 free(txn->mt_u.dirty_list);
2459 if (mdb_midl_shrink(&txn->mt_free_pgs))
2460 env->me_free_pgs = txn->mt_free_pgs;
2461 env->me_pghead = NULL;
2465 /* The writer mutex was locked in mdb_txn_begin. */
2467 UNLOCK_MUTEX_W(env);
2472 mdb_txn_reset(MDB_txn *txn)
2477 /* This call is only valid for read-only txns */
2478 if (!(txn->mt_flags & MDB_TXN_RDONLY))
2481 mdb_txn_reset0(txn, "reset");
2485 mdb_txn_abort(MDB_txn *txn)
2491 mdb_txn_abort(txn->mt_child);
2493 mdb_txn_reset0(txn, "abort");
2494 /* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
2495 if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader)
2496 txn->mt_u.reader->mr_pid = 0;
2501 /** Save the freelist as of this transaction to the freeDB.
2502 * This changes the freelist. Keep trying until it stabilizes.
2505 mdb_freelist_save(MDB_txn *txn)
2507 /* env->me_pghead[] can grow and shrink during this call.
2508 * env->me_pglast and txn->mt_free_pgs[] can only grow.
2509 * Page numbers cannot disappear from txn->mt_free_pgs[].
2512 MDB_env *env = txn->mt_env;
2513 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
2514 txnid_t pglast = 0, head_id = 0;
2515 pgno_t freecnt = 0, *free_pgs, *mop;
2516 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
2518 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
2520 if (env->me_pghead) {
2521 /* Make sure first page of freeDB is touched and on freelist */
2522 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
2523 if (rc && rc != MDB_NOTFOUND)
2527 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
2528 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
2529 ? SSIZE_MAX : maxfree_1pg;
2532 /* Come back here after each Put() in case freelist changed */
2537 /* If using records from freeDB which we have not yet
2538 * deleted, delete them and any we reserved for me_pghead.
2540 while (pglast < env->me_pglast) {
2541 rc = mdb_cursor_first(&mc, &key, NULL);
2544 pglast = head_id = *(txnid_t *)key.mv_data;
2545 total_room = head_room = 0;
2546 assert(pglast <= env->me_pglast);
2547 rc = mdb_cursor_del(&mc, 0);
2552 /* Save the IDL of pages freed by this txn, to a single record */
2553 if (freecnt < txn->mt_free_pgs[0]) {
2555 /* Make sure last page of freeDB is touched and on freelist */
2556 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
2557 if (rc && rc != MDB_NOTFOUND)
2560 free_pgs = txn->mt_free_pgs;
2561 /* Write to last page of freeDB */
2562 key.mv_size = sizeof(txn->mt_txnid);
2563 key.mv_data = &txn->mt_txnid;
2565 freecnt = free_pgs[0];
2566 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
2567 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2570 /* Retry if mt_free_pgs[] grew during the Put() */
2571 free_pgs = txn->mt_free_pgs;
2572 } while (freecnt < free_pgs[0]);
2573 mdb_midl_sort(free_pgs);
2574 memcpy(data.mv_data, free_pgs, data.mv_size);
2577 unsigned int i = free_pgs[0];
2578 DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
2579 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
2581 DPRINTF(("IDL %"Z"u", free_pgs[i]));
2587 mop = env->me_pghead;
2588 mop_len = mop ? mop[0] : 0;
2590 /* Reserve records for me_pghead[]. Split it if multi-page,
2591 * to avoid searching freeDB for a page range. Use keys in
2592 * range [1,me_pglast]: Smaller than txnid of oldest reader.
2594 if (total_room >= mop_len) {
2595 if (total_room == mop_len || --more < 0)
2597 } else if (head_room >= maxfree_1pg && head_id > 1) {
2598 /* Keep current record (overflow page), add a new one */
2602 /* (Re)write {key = head_id, IDL length = head_room} */
2603 total_room -= head_room;
2604 head_room = mop_len - total_room;
2605 if (head_room > maxfree_1pg && head_id > 1) {
2606 /* Overflow multi-page for part of me_pghead */
2607 head_room /= head_id; /* amortize page sizes */
2608 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
2609 } else if (head_room < 0) {
2610 /* Rare case, not bothering to delete this record */
2613 key.mv_size = sizeof(head_id);
2614 key.mv_data = &head_id;
2615 data.mv_size = (head_room + 1) * sizeof(pgno_t);
2616 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
2619 /* IDL is initially empty, zero out at least the length */
2620 pgs = (pgno_t *)data.mv_data;
2621 j = head_room > clean_limit ? head_room : 0;
2625 total_room += head_room;
2628 /* Fill in the reserved me_pghead records */
2634 rc = mdb_cursor_first(&mc, &key, &data);
2635 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
2636 unsigned flags = MDB_CURRENT;
2637 txnid_t id = *(txnid_t *)key.mv_data;
2638 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
2641 assert(len >= 0 && id <= env->me_pglast);
2643 if (len > mop_len) {
2645 data.mv_size = (len + 1) * sizeof(MDB_ID);
2648 data.mv_data = mop -= len;
2651 rc = mdb_cursor_put(&mc, &key, &data, flags);
2653 if (rc || !(mop_len -= len))
2660 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
2661 * @param[in] txn the transaction that's being committed
2662 * @param[in] keep number of initial pages in dirty_list to keep dirty.
2663 * @return 0 on success, non-zero on failure.
2666 mdb_page_flush(MDB_txn *txn, int keep)
2668 MDB_env *env = txn->mt_env;
2669 MDB_ID2L dl = txn->mt_u.dirty_list;
2670 unsigned psize = env->me_psize, j;
2671 int i, pagecount = dl[0].mid, rc;
2672 size_t size = 0, pos = 0;
2674 MDB_page *dp = NULL;
2678 struct iovec iov[MDB_COMMIT_PAGES];
2679 ssize_t wpos = 0, wsize = 0, wres;
2680 size_t next_pos = 1; /* impossible pos, so pos != next_pos */
2686 if (env->me_flags & MDB_WRITEMAP) {
2687 /* Clear dirty flags */
2688 while (++i <= pagecount) {
2690 /* Don't flush this page yet */
2691 if (dp->mp_flags & P_KEEP) {
2692 dp->mp_flags ^= P_KEEP;
2696 dp->mp_flags &= ~P_DIRTY;
2701 /* Write the pages */
2703 if (++i <= pagecount) {
2705 /* Don't flush this page yet */
2706 if (dp->mp_flags & P_KEEP) {
2707 dp->mp_flags ^= P_KEEP;
2712 /* clear dirty flag */
2713 dp->mp_flags &= ~P_DIRTY;
2716 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
2721 /* Windows actually supports scatter/gather I/O, but only on
2722 * unbuffered file handles. Since we're relying on the OS page
2723 * cache for all our data, that's self-defeating. So we just
2724 * write pages one at a time. We use the ov structure to set
2725 * the write offset, to at least save the overhead of a Seek
2728 DPRINTF(("committing page %"Z"u", pgno));
2729 memset(&ov, 0, sizeof(ov));
2730 ov.Offset = pos & 0xffffffff;
2731 ov.OffsetHigh = pos >> 16 >> 16;
2732 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
2734 DPRINTF(("WriteFile: %d", rc));
2738 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
2739 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
2741 /* Write previous page(s) */
2742 #ifdef MDB_USE_PWRITEV
2743 wres = pwritev(env->me_fd, iov, n, wpos);
2746 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
2748 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
2750 DPRINTF(("lseek: %s", strerror(rc)));
2753 wres = writev(env->me_fd, iov, n);
2756 if (wres != wsize) {
2759 DPRINTF(("Write error: %s", strerror(rc)));
2761 rc = EIO; /* TODO: Use which error code? */
2762 DPUTS("short write, filesystem full?");
2773 DPRINTF(("committing page %"Z"u", pgno));
2774 next_pos = pos + size;
2775 iov[n].iov_len = size;
2776 iov[n].iov_base = (char *)dp;
2782 for (i = keep; ++i <= pagecount; ) {
2784 /* This is a page we skipped above */
2787 dl[j].mid = dp->mp_pgno;
2790 mdb_dpage_free(env, dp);
2795 txn->mt_dirty_room += i - j;
2801 mdb_txn_commit(MDB_txn *txn)
2807 assert(txn != NULL);
2808 assert(txn->mt_env != NULL);
2810 if (txn->mt_child) {
2811 rc = mdb_txn_commit(txn->mt_child);
2812 txn->mt_child = NULL;
2819 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
2820 mdb_dbis_update(txn, 1);
2821 txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
2826 if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
2827 DPUTS("error flag is set, can't commit");
2829 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
2834 if (txn->mt_parent) {
2835 MDB_txn *parent = txn->mt_parent;
2838 unsigned x, y, len, ps_len;
2840 /* Append our free list to parent's */
2841 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
2844 mdb_midl_free(txn->mt_free_pgs);
2845 /* Failures after this must either undo the changes
2846 * to the parent or set MDB_TXN_ERROR in the parent.
2849 parent->mt_next_pgno = txn->mt_next_pgno;
2850 parent->mt_flags = txn->mt_flags;
2852 /* Merge our cursors into parent's and close them */
2853 mdb_cursors_close(txn, 1);
2855 /* Update parent's DB table. */
2856 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
2857 parent->mt_numdbs = txn->mt_numdbs;
2858 parent->mt_dbflags[0] = txn->mt_dbflags[0];
2859 parent->mt_dbflags[1] = txn->mt_dbflags[1];
2860 for (i=2; i<txn->mt_numdbs; i++) {
2861 /* preserve parent's DB_NEW status */
2862 x = parent->mt_dbflags[i] & DB_NEW;
2863 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
2866 dst = parent->mt_u.dirty_list;
2867 src = txn->mt_u.dirty_list;
2868 /* Remove anything in our dirty list from parent's spill list */
2869 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
2871 pspill[0] = (pgno_t)-1;
2872 /* Mark our dirty pages as deleted in parent spill list */
2873 for (i=0, len=src[0].mid; ++i <= len; ) {
2874 MDB_ID pn = src[i].mid << 1;
2875 while (pn > pspill[x])
2877 if (pn == pspill[x]) {
2882 /* Squash deleted pagenums if we deleted any */
2883 for (x=y; ++x <= ps_len; )
2884 if (!(pspill[x] & 1))
2885 pspill[++y] = pspill[x];
2889 /* Find len = length of merging our dirty list with parent's */
2891 dst[0].mid = 0; /* simplify loops */
2892 if (parent->mt_parent) {
2893 len = x + src[0].mid;
2894 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
2895 for (i = x; y && i; y--) {
2896 pgno_t yp = src[y].mid;
2897 while (yp < dst[i].mid)
2899 if (yp == dst[i].mid) {
2904 } else { /* Simplify the above for single-ancestor case */
2905 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
2907 /* Merge our dirty list with parent's */
2909 for (i = len; y; dst[i--] = src[y--]) {
2910 pgno_t yp = src[y].mid;
2911 while (yp < dst[x].mid)
2912 dst[i--] = dst[x--];
2913 if (yp == dst[x].mid)
2914 free(dst[x--].mptr);
2918 free(txn->mt_u.dirty_list);
2919 parent->mt_dirty_room = txn->mt_dirty_room;
2920 if (txn->mt_spill_pgs) {
2921 if (parent->mt_spill_pgs) {
2922 /* TODO: Prevent failure here, so parent does not fail */
2923 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
2925 parent->mt_flags |= MDB_TXN_ERROR;
2926 mdb_midl_free(txn->mt_spill_pgs);
2927 mdb_midl_sort(parent->mt_spill_pgs);
2929 parent->mt_spill_pgs = txn->mt_spill_pgs;
2933 parent->mt_child = NULL;
2934 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
2939 if (txn != env->me_txn) {
2940 DPUTS("attempt to commit unknown transaction");
2945 mdb_cursors_close(txn, 0);
2947 if (!txn->mt_u.dirty_list[0].mid &&
2948 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
2951 DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
2952 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
2954 /* Update DB root pointers */
2955 if (txn->mt_numdbs > 2) {
2959 data.mv_size = sizeof(MDB_db);
2961 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
2962 for (i = 2; i < txn->mt_numdbs; i++) {
2963 if (txn->mt_dbflags[i] & DB_DIRTY) {
2964 data.mv_data = &txn->mt_dbs[i];
2965 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
2972 rc = mdb_freelist_save(txn);
2976 mdb_midl_free(env->me_pghead);
2977 env->me_pghead = NULL;
2978 if (mdb_midl_shrink(&txn->mt_free_pgs))
2979 env->me_free_pgs = txn->mt_free_pgs;
2985 if ((rc = mdb_page_flush(txn, 0)) ||
2986 (rc = mdb_env_sync(env, 0)) ||
2987 (rc = mdb_env_write_meta(txn)))
2993 mdb_dbis_update(txn, 1);
2996 UNLOCK_MUTEX_W(env);
3006 /** Read the environment parameters of a DB environment before
3007 * mapping it into memory.
3008 * @param[in] env the environment handle
3009 * @param[out] meta address of where to store the meta information
3010 * @return 0 on success, non-zero on failure.
3013 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3019 enum { Size = sizeof(pbuf) };
3021 /* We don't know the page size yet, so use a minimum value.
3022 * Read both meta pages so we can use the latest one.
3025 for (i=off=0; i<2; i++, off = meta->mm_psize) {
3029 memset(&ov, 0, sizeof(ov));
3031 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3032 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3035 rc = pread(env->me_fd, &pbuf, Size, off);
3038 if (rc == 0 && off == 0)
3040 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3041 DPRINTF(("read: %s", mdb_strerror(rc)));
3045 p = (MDB_page *)&pbuf;
3047 if (!F_ISSET(p->mp_flags, P_META)) {
3048 DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
3053 if (m->mm_magic != MDB_MAGIC) {
3054 DPUTS("meta has invalid magic");
3058 if (m->mm_version != MDB_DATA_VERSION) {
3059 DPRINTF(("database is version %u, expected version %u",
3060 m->mm_version, MDB_DATA_VERSION));
3061 return MDB_VERSION_MISMATCH;
3064 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3070 /** Write the environment parameters of a freshly created DB environment.
3071 * @param[in] env the environment handle
3072 * @param[out] meta address of where to store the meta information
3073 * @return 0 on success, non-zero on failure.
3076 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3084 memset(&ov, 0, sizeof(ov));
3085 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3087 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3090 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3091 len = pwrite(fd, ptr, size, pos); \
3092 rc = (len >= 0); } while(0)
3095 DPUTS("writing new meta page");
3097 psize = env->me_psize;
3099 meta->mm_magic = MDB_MAGIC;
3100 meta->mm_version = MDB_DATA_VERSION;
3101 meta->mm_mapsize = env->me_mapsize;
3102 meta->mm_psize = psize;
3103 meta->mm_last_pg = 1;
3104 meta->mm_flags = env->me_flags & 0xffff;
3105 meta->mm_flags |= MDB_INTEGERKEY;
3106 meta->mm_dbs[0].md_root = P_INVALID;
3107 meta->mm_dbs[1].md_root = P_INVALID;
3109 p = calloc(2, psize);
3111 p->mp_flags = P_META;
3112 *(MDB_meta *)METADATA(p) = *meta;
3114 q = (MDB_page *)((char *)p + psize);
3116 q->mp_flags = P_META;
3117 *(MDB_meta *)METADATA(q) = *meta;
3119 DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0);
3122 else if ((unsigned) len == psize * 2)
3130 /** Update the environment info to commit a transaction.
3131 * @param[in] txn the transaction that's being committed
3132 * @return 0 on success, non-zero on failure.
3135 mdb_env_write_meta(MDB_txn *txn)
3138 MDB_meta meta, metab, *mp;
3140 int rc, len, toggle;
3149 assert(txn != NULL);
3150 assert(txn->mt_env != NULL);
3152 toggle = txn->mt_txnid & 1;
3153 DPRINTF(("writing meta page %d for root page %"Z"u",
3154 toggle, txn->mt_dbs[MAIN_DBI].md_root));
3157 mp = env->me_metas[toggle];
3159 if (env->me_flags & MDB_WRITEMAP) {
3160 /* Persist any increases of mapsize config */
3161 if (env->me_mapsize > mp->mm_mapsize)
3162 mp->mm_mapsize = env->me_mapsize;
3163 mp->mm_dbs[0] = txn->mt_dbs[0];
3164 mp->mm_dbs[1] = txn->mt_dbs[1];
3165 mp->mm_last_pg = txn->mt_next_pgno - 1;
3166 mp->mm_txnid = txn->mt_txnid;
3167 if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
3168 unsigned meta_size = env->me_psize;
3169 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
3172 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
3173 if (meta_size < env->me_os_psize)
3174 meta_size += meta_size;
3179 if (MDB_MSYNC(ptr, meta_size, rc)) {
3186 metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
3187 metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
3189 ptr = (char *)&meta;
3190 if (env->me_mapsize > mp->mm_mapsize) {
3191 /* Persist any increases of mapsize config */
3192 meta.mm_mapsize = env->me_mapsize;
3193 off = offsetof(MDB_meta, mm_mapsize);
3195 off = offsetof(MDB_meta, mm_dbs[0].md_depth);
3197 len = sizeof(MDB_meta) - off;
3200 meta.mm_dbs[0] = txn->mt_dbs[0];
3201 meta.mm_dbs[1] = txn->mt_dbs[1];
3202 meta.mm_last_pg = txn->mt_next_pgno - 1;
3203 meta.mm_txnid = txn->mt_txnid;
3206 off += env->me_psize;
3209 /* Write to the SYNC fd */
3210 mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
3211 env->me_fd : env->me_mfd;
3214 memset(&ov, 0, sizeof(ov));
3216 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
3220 rc = pwrite(mfd, ptr, len, off);
3223 rc = rc < 0 ? ErrCode() : EIO;
3224 DPUTS("write failed, disk error?");
3225 /* On a failure, the pagecache still contains the new data.
3226 * Write some old data back, to prevent it from being used.
3227 * Use the non-SYNC fd; we know it will fail anyway.
3229 meta.mm_last_pg = metab.mm_last_pg;
3230 meta.mm_txnid = metab.mm_txnid;
3232 memset(&ov, 0, sizeof(ov));
3234 WriteFile(env->me_fd, ptr, len, NULL, &ov);
3236 r2 = pwrite(env->me_fd, ptr, len, off);
3237 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
3240 env->me_flags |= MDB_FATAL_ERROR;
3244 /* Memory ordering issues are irrelevant; since the entire writer
3245 * is wrapped by wmutex, all of these changes will become visible
3246 * after the wmutex is unlocked. Since the DB is multi-version,
3247 * readers will get consistent data regardless of how fresh or
3248 * how stale their view of these values is.
3251 env->me_txns->mti_txnid = txn->mt_txnid;
3256 /** Check both meta pages to see which one is newer.
3257 * @param[in] env the environment handle
3258 * @return meta toggle (0 or 1).
3261 mdb_env_pick_meta(const MDB_env *env)
3263 return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
3267 mdb_env_create(MDB_env **env)
3271 e = calloc(1, sizeof(MDB_env));
3275 e->me_maxreaders = DEFAULT_READERS;
3276 e->me_maxdbs = e->me_numdbs = 2;
3277 e->me_fd = INVALID_HANDLE_VALUE;
3278 e->me_lfd = INVALID_HANDLE_VALUE;
3279 e->me_mfd = INVALID_HANDLE_VALUE;
3280 #ifdef MDB_USE_POSIX_SEM
3281 e->me_rmutex = SEM_FAILED;
3282 e->me_wmutex = SEM_FAILED;
3284 e->me_pid = getpid();
3285 GET_PAGESIZE(e->me_os_psize);
3286 VGMEMP_CREATE(e,0,0);
3292 mdb_env_map(MDB_env *env, void *addr, int newsize)
3295 unsigned int flags = env->me_flags;
3299 LONG sizelo, sizehi;
3300 sizelo = env->me_mapsize & 0xffffffff;
3301 sizehi = env->me_mapsize >> 16 >> 16; /* only needed on Win64 */
3303 /* Windows won't create mappings for zero length files.
3304 * Just allocate the maxsize right now.
3307 if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
3308 || !SetEndOfFile(env->me_fd)
3309 || SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
3312 mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
3313 PAGE_READWRITE : PAGE_READONLY,
3314 sizehi, sizelo, NULL);
3317 env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
3318 FILE_MAP_WRITE : FILE_MAP_READ,
3319 0, 0, env->me_mapsize, addr);
3320 rc = env->me_map ? 0 : ErrCode();
3325 int prot = PROT_READ;
3326 if (flags & MDB_WRITEMAP) {
3328 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
3331 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
3333 if (env->me_map == MAP_FAILED) {
3338 if (flags & MDB_NORDAHEAD) {
3339 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
3341 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
3343 #ifdef POSIX_MADV_RANDOM
3344 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
3345 #endif /* POSIX_MADV_RANDOM */
3346 #endif /* MADV_RANDOM */
3350 /* Can happen because the address argument to mmap() is just a
3351 * hint. mmap() can pick another, e.g. if the range is in use.
3352 * The MAP_FIXED flag would prevent that, but then mmap could
3353 * instead unmap existing pages to make room for the new map.
3355 if (addr && env->me_map != addr)
3356 return EBUSY; /* TODO: Make a new MDB_* error code? */
3358 p = (MDB_page *)env->me_map;
3359 env->me_metas[0] = METADATA(p);
3360 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
3366 mdb_env_set_mapsize(MDB_env *env, size_t size)
3368 /* If env is already open, caller is responsible for making
3369 * sure there are no active txns.
3377 size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
3378 else if (size < env->me_mapsize) {
3379 /* If the configured size is smaller, make sure it's
3380 * still big enough. Silently round up to minimum if not.
3382 size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize;
3386 munmap(env->me_map, env->me_mapsize);
3387 env->me_mapsize = size;
3388 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
3389 rc = mdb_env_map(env, old, 1);
3393 env->me_mapsize = size;
3395 env->me_maxpg = env->me_mapsize / env->me_psize;
3400 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
3404 env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
3409 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
3411 if (env->me_map || readers < 1)
3413 env->me_maxreaders = readers;
3418 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
3420 if (!env || !readers)
3422 *readers = env->me_maxreaders;
3426 /** Further setup required for opening an MDB environment
3429 mdb_env_open2(MDB_env *env)
3431 unsigned int flags = env->me_flags;
3432 int i, newenv = 0, rc;
3436 /* See if we should use QueryLimited */
3438 if ((rc & 0xff) > 5)
3439 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
3441 env->me_pidquery = PROCESS_QUERY_INFORMATION;
3444 memset(&meta, 0, sizeof(meta));
3446 if ((i = mdb_env_read_header(env, &meta)) != 0) {
3449 DPUTS("new mdbenv");
3451 env->me_psize = env->me_os_psize;
3452 if (env->me_psize > MAX_PAGESIZE)
3453 env->me_psize = MAX_PAGESIZE;
3455 env->me_psize = meta.mm_psize;
3458 /* Was a mapsize configured? */
3459 if (!env->me_mapsize) {
3460 /* If this is a new environment, take the default,
3461 * else use the size recorded in the existing env.
3463 env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
3464 } else if (env->me_mapsize < meta.mm_mapsize) {
3465 /* If the configured size is smaller, make sure it's
3466 * still big enough. Silently round up to minimum if not.
3468 size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
3469 if (env->me_mapsize < minsize)
3470 env->me_mapsize = minsize;
3473 rc = mdb_env_map(env, meta.mm_address, newenv);
3478 if (flags & MDB_FIXEDMAP)
3479 meta.mm_address = env->me_map;
3480 i = mdb_env_init_meta(env, &meta);
3481 if (i != MDB_SUCCESS) {
3485 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
3486 env->me_nodemax = (env->me_psize - PAGEHDRSZ) / MDB_MINKEYS;
3488 env->me_maxpg = env->me_mapsize / env->me_psize;
3491 int toggle = mdb_env_pick_meta(env);
3492 MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
3494 DPRINTF(("opened database version %u, pagesize %u",
3495 env->me_metas[0]->mm_version, env->me_psize));
3496 DPRINTF(("using meta page %d", toggle));
3497 DPRINTF(("depth: %u", db->md_depth));
3498 DPRINTF(("entries: %"Z"u", db->md_entries));
3499 DPRINTF(("branch pages: %"Z"u", db->md_branch_pages));
3500 DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages));
3501 DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
3502 DPRINTF(("root: %"Z"u", db->md_root));
3510 /** Release a reader thread's slot in the reader lock table.
3511 * This function is called automatically when a thread exits.
3512 * @param[in] ptr This points to the slot in the reader lock table.
3515 mdb_env_reader_dest(void *ptr)
3517 MDB_reader *reader = ptr;
3523 /** Junk for arranging thread-specific callbacks on Windows. This is
3524 * necessarily platform and compiler-specific. Windows supports up
3525 * to 1088 keys. Let's assume nobody opens more than 64 environments
3526 * in a single process, for now. They can override this if needed.
3528 #ifndef MAX_TLS_KEYS
3529 #define MAX_TLS_KEYS 64
3531 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
3532 static int mdb_tls_nkeys;
3534 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
3538 case DLL_PROCESS_ATTACH: break;
3539 case DLL_THREAD_ATTACH: break;
3540 case DLL_THREAD_DETACH:
3541 for (i=0; i<mdb_tls_nkeys; i++) {
3542 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
3543 mdb_env_reader_dest(r);
3546 case DLL_PROCESS_DETACH: break;
3551 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3553 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
3557 /* Force some symbol references.
3558 * _tls_used forces the linker to create the TLS directory if not already done
3559 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
3561 #pragma comment(linker, "/INCLUDE:_tls_used")
3562 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
3563 #pragma const_seg(".CRT$XLB")
3564 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
3565 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3568 #pragma comment(linker, "/INCLUDE:__tls_used")
3569 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
3570 #pragma data_seg(".CRT$XLB")
3571 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
3573 #endif /* WIN 32/64 */
3574 #endif /* !__GNUC__ */
3577 /** Downgrade the exclusive lock on the region back to shared */
3579 mdb_env_share_locks(MDB_env *env, int *excl)
3581 int rc = 0, toggle = mdb_env_pick_meta(env);
3583 env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
3588 /* First acquire a shared lock. The Unlock will
3589 * then release the existing exclusive lock.
3591 memset(&ov, 0, sizeof(ov));
3592 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3595 UnlockFile(env->me_lfd, 0, 0, 1, 0);
3601 struct flock lock_info;
3602 /* The shared lock replaces the existing lock */
3603 memset((void *)&lock_info, 0, sizeof(lock_info));
3604 lock_info.l_type = F_RDLCK;
3605 lock_info.l_whence = SEEK_SET;
3606 lock_info.l_start = 0;
3607 lock_info.l_len = 1;
3608 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3609 (rc = ErrCode()) == EINTR) ;
3610 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
3617 /** Try to get exlusive lock, otherwise shared.
3618 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
3621 mdb_env_excl_lock(MDB_env *env, int *excl)
3625 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
3629 memset(&ov, 0, sizeof(ov));
3630 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
3637 struct flock lock_info;
3638 memset((void *)&lock_info, 0, sizeof(lock_info));
3639 lock_info.l_type = F_WRLCK;
3640 lock_info.l_whence = SEEK_SET;
3641 lock_info.l_start = 0;
3642 lock_info.l_len = 1;
3643 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
3644 (rc = ErrCode()) == EINTR) ;
3648 # ifdef MDB_USE_POSIX_SEM
3649 if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
3652 lock_info.l_type = F_RDLCK;
3653 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
3654 (rc = ErrCode()) == EINTR) ;
3664 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
3666 * @(#) $Revision: 5.1 $
3667 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
3668 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
3670 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
3674 * Please do not copyright this code. This code is in the public domain.
3676 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
3677 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
3678 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
3679 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
3680 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
3681 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
3682 * PERFORMANCE OF THIS SOFTWARE.
3685 * chongo <Landon Curt Noll> /\oo/\
3686 * http://www.isthe.com/chongo/
3688 * Share and Enjoy! :-)
3691 typedef unsigned long long mdb_hash_t;
3692 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
3694 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
3695 * @param[in] val value to hash
3696 * @param[in] hval initial value for hash
3697 * @return 64 bit hash
3699 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
3700 * hval arg on the first call.
3703 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
3705 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
3706 unsigned char *end = s + val->mv_size;
3708 * FNV-1a hash each octet of the string
3711 /* xor the bottom with the current octet */
3712 hval ^= (mdb_hash_t)*s++;
3714 /* multiply by the 64 bit FNV magic prime mod 2^64 */
3715 hval += (hval << 1) + (hval << 4) + (hval << 5) +
3716 (hval << 7) + (hval << 8) + (hval << 40);
3718 /* return our new hash value */
3722 /** Hash the string and output the encoded hash.
3723 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
3724 * very short name limits. We don't care about the encoding being reversible,
3725 * we just want to preserve as many bits of the input as possible in a
3726 * small printable string.
3727 * @param[in] str string to hash
3728 * @param[out] encbuf an array of 11 chars to hold the hash
3730 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
3733 mdb_pack85(unsigned long l, char *out)
3737 for (i=0; i<5; i++) {
3738 *out++ = mdb_a85[l % 85];
3744 mdb_hash_enc(MDB_val *val, char *encbuf)
3746 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
3748 mdb_pack85(h, encbuf);
3749 mdb_pack85(h>>32, encbuf+5);
3754 /** Open and/or initialize the lock region for the environment.
3755 * @param[in] env The MDB environment.
3756 * @param[in] lpath The pathname of the file used for the lock region.
3757 * @param[in] mode The Unix permissions for the file, if we create it.
3758 * @param[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive
3759 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
3760 * @return 0 on success, non-zero on failure.
3763 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
3766 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
3768 # define MDB_ERRCODE_ROFS EROFS
3769 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
3770 # define MDB_CLOEXEC O_CLOEXEC
3773 # define MDB_CLOEXEC 0
3780 env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
3781 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
3782 FILE_ATTRIBUTE_NORMAL, NULL);
3784 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
3786 if (env->me_lfd == INVALID_HANDLE_VALUE) {
3788 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
3793 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
3794 /* Lose record locks when exec*() */
3795 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
3796 fcntl(env->me_lfd, F_SETFD, fdflags);
3799 if (!(env->me_flags & MDB_NOTLS)) {
3800 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
3803 env->me_flags |= MDB_ENV_TXKEY;
3805 /* Windows TLS callbacks need help finding their TLS info. */
3806 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
3810 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
3814 /* Try to get exclusive lock. If we succeed, then
3815 * nobody is using the lock region and we should initialize it.
3817 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
3820 size = GetFileSize(env->me_lfd, NULL);
3822 size = lseek(env->me_lfd, 0, SEEK_END);
3823 if (size == -1) goto fail_errno;
3825 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
3826 if (size < rsize && *excl > 0) {
3828 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
3829 || !SetEndOfFile(env->me_lfd))
3832 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
3836 size = rsize - sizeof(MDB_txninfo);
3837 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
3842 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
3844 if (!mh) goto fail_errno;
3845 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
3847 if (!env->me_txns) goto fail_errno;
3849 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
3851 if (m == MAP_FAILED) goto fail_errno;
3857 BY_HANDLE_FILE_INFORMATION stbuf;
3866 if (!mdb_sec_inited) {
3867 InitializeSecurityDescriptor(&mdb_null_sd,
3868 SECURITY_DESCRIPTOR_REVISION);
3869 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
3870 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
3871 mdb_all_sa.bInheritHandle = FALSE;
3872 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
3875 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
3876 idbuf.volume = stbuf.dwVolumeSerialNumber;
3877 idbuf.nhigh = stbuf.nFileIndexHigh;
3878 idbuf.nlow = stbuf.nFileIndexLow;
3879 val.mv_data = &idbuf;
3880 val.mv_size = sizeof(idbuf);
3881 mdb_hash_enc(&val, encbuf);
3882 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
3883 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
3884 env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
3885 if (!env->me_rmutex) goto fail_errno;
3886 env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
3887 if (!env->me_wmutex) goto fail_errno;
3888 #elif defined(MDB_USE_POSIX_SEM)
3897 #if defined(__NetBSD__)
3898 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
3900 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
3901 idbuf.dev = stbuf.st_dev;
3902 idbuf.ino = stbuf.st_ino;
3903 val.mv_data = &idbuf;
3904 val.mv_size = sizeof(idbuf);
3905 mdb_hash_enc(&val, encbuf);
3906 #ifdef MDB_SHORT_SEMNAMES
3907 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
3909 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
3910 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
3911 /* Clean up after a previous run, if needed: Try to
3912 * remove both semaphores before doing anything else.
3914 sem_unlink(env->me_txns->mti_rmname);
3915 sem_unlink(env->me_txns->mti_wmname);
3916 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
3917 O_CREAT|O_EXCL, mode, 1);
3918 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3919 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
3920 O_CREAT|O_EXCL, mode, 1);
3921 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3922 #else /* MDB_USE_POSIX_SEM */
3923 pthread_mutexattr_t mattr;
3925 if ((rc = pthread_mutexattr_init(&mattr))
3926 || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
3927 || (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
3928 || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
3930 pthread_mutexattr_destroy(&mattr);
3931 #endif /* _WIN32 || MDB_USE_POSIX_SEM */
3933 env->me_txns->mti_magic = MDB_MAGIC;
3934 env->me_txns->mti_format = MDB_LOCK_FORMAT;
3935 env->me_txns->mti_txnid = 0;
3936 env->me_txns->mti_numreaders = 0;
3939 if (env->me_txns->mti_magic != MDB_MAGIC) {
3940 DPUTS("lock region has invalid magic");
3944 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
3945 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
3946 env->me_txns->mti_format, MDB_LOCK_FORMAT));
3947 rc = MDB_VERSION_MISMATCH;
3951 if (rc && rc != EACCES && rc != EAGAIN) {
3955 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
3956 if (!env->me_rmutex) goto fail_errno;
3957 env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
3958 if (!env->me_wmutex) goto fail_errno;
3959 #elif defined(MDB_USE_POSIX_SEM)
3960 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
3961 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
3962 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
3963 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
3974 /** The name of the lock file in the DB environment */
3975 #define LOCKNAME "/lock.mdb"
3976 /** The name of the data file in the DB environment */
3977 #define DATANAME "/data.mdb"
3978 /** The suffix of the lock file when no subdir is used */
3979 #define LOCKSUFF "-lock"
3980 /** Only a subset of the @ref mdb_env flags can be changed
3981 * at runtime. Changing other flags requires closing the
3982 * environment and re-opening it with the new flags.
3984 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
3985 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| \
3986 MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
3989 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
3991 int oflags, rc, len, excl = -1;
3992 char *lpath, *dpath;
3994 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
3998 if (flags & MDB_NOSUBDIR) {
3999 rc = len + sizeof(LOCKSUFF) + len + 1;
4001 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
4006 if (flags & MDB_NOSUBDIR) {
4007 dpath = lpath + len + sizeof(LOCKSUFF);
4008 sprintf(lpath, "%s" LOCKSUFF, path);
4009 strcpy(dpath, path);
4011 dpath = lpath + len + sizeof(LOCKNAME);
4012 sprintf(lpath, "%s" LOCKNAME, path);
4013 sprintf(dpath, "%s" DATANAME, path);
4017 flags |= env->me_flags;
4018 if (flags & MDB_RDONLY) {
4019 /* silently ignore WRITEMAP when we're only getting read access */
4020 flags &= ~MDB_WRITEMAP;
4022 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
4023 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
4026 env->me_flags = flags |= MDB_ENV_ACTIVE;
4030 env->me_path = strdup(path);
4031 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
4032 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
4033 if (!(env->me_dbxs && env->me_path && env->me_dbflags)) {
4038 /* For RDONLY, get lockfile after we know datafile exists */
4039 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
4040 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4046 if (F_ISSET(flags, MDB_RDONLY)) {
4047 oflags = GENERIC_READ;
4048 len = OPEN_EXISTING;
4050 oflags = GENERIC_READ|GENERIC_WRITE;
4053 mode = FILE_ATTRIBUTE_NORMAL;
4054 env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
4055 NULL, len, mode, NULL);
4057 if (F_ISSET(flags, MDB_RDONLY))
4060 oflags = O_RDWR | O_CREAT;
4062 env->me_fd = open(dpath, oflags, mode);
4064 if (env->me_fd == INVALID_HANDLE_VALUE) {
4069 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
4070 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
4075 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
4076 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
4077 env->me_mfd = env->me_fd;
4079 /* Synchronous fd for meta writes. Needed even with
4080 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
4083 len = OPEN_EXISTING;
4084 env->me_mfd = CreateFile(dpath, oflags,
4085 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
4086 mode | FILE_FLAG_WRITE_THROUGH, NULL);
4089 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
4091 if (env->me_mfd == INVALID_HANDLE_VALUE) {
4096 DPRINTF(("opened dbenv %p", (void *) env));
4098 rc = mdb_env_share_locks(env, &excl);
4102 if (!((flags & MDB_RDONLY) ||
4103 (env->me_pbuf = calloc(1, env->me_psize))))
4109 mdb_env_close0(env, excl);
4115 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
4117 mdb_env_close0(MDB_env *env, int excl)
4121 if (!(env->me_flags & MDB_ENV_ACTIVE))
4124 /* Doing this here since me_dbxs may not exist during mdb_env_close */
4125 for (i = env->me_maxdbs; --i > MAIN_DBI; )
4126 free(env->me_dbxs[i].md_name.mv_data);
4129 free(env->me_dbflags);
4132 free(env->me_dirty_list);
4133 mdb_midl_free(env->me_free_pgs);
4135 if (env->me_flags & MDB_ENV_TXKEY) {
4136 pthread_key_delete(env->me_txkey);
4138 /* Delete our key from the global list */
4139 for (i=0; i<mdb_tls_nkeys; i++)
4140 if (mdb_tls_keys[i] == env->me_txkey) {
4141 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
4149 munmap(env->me_map, env->me_mapsize);
4151 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
4152 (void) close(env->me_mfd);
4153 if (env->me_fd != INVALID_HANDLE_VALUE)
4154 (void) close(env->me_fd);
4156 MDB_PID_T pid = env->me_pid;
4157 /* Clearing readers is done in this function because
4158 * me_txkey with its destructor must be disabled first.
4160 for (i = env->me_numreaders; --i >= 0; )
4161 if (env->me_txns->mti_readers[i].mr_pid == pid)
4162 env->me_txns->mti_readers[i].mr_pid = 0;
4164 if (env->me_rmutex) {
4165 CloseHandle(env->me_rmutex);
4166 if (env->me_wmutex) CloseHandle(env->me_wmutex);
4168 /* Windows automatically destroys the mutexes when
4169 * the last handle closes.
4171 #elif defined(MDB_USE_POSIX_SEM)
4172 if (env->me_rmutex != SEM_FAILED) {
4173 sem_close(env->me_rmutex);
4174 if (env->me_wmutex != SEM_FAILED)
4175 sem_close(env->me_wmutex);
4176 /* If we have the filelock: If we are the
4177 * only remaining user, clean up semaphores.
4180 mdb_env_excl_lock(env, &excl);
4182 sem_unlink(env->me_txns->mti_rmname);
4183 sem_unlink(env->me_txns->mti_wmname);
4187 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
4189 if (env->me_lfd != INVALID_HANDLE_VALUE) {
4192 /* Unlock the lockfile. Windows would have unlocked it
4193 * after closing anyway, but not necessarily at once.
4195 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4198 (void) close(env->me_lfd);
4201 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
4205 mdb_env_copyfd(MDB_env *env, HANDLE fd)
4207 MDB_txn *txn = NULL;
4213 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
4217 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
4220 /* Do the lock/unlock of the reader mutex before starting the
4221 * write txn. Otherwise other read txns could block writers.
4223 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
4228 /* We must start the actual read txn after blocking writers */
4229 mdb_txn_reset0(txn, "reset-stage1");
4231 /* Temporarily block writers until we snapshot the meta pages */
4234 rc = mdb_txn_renew0(txn);
4236 UNLOCK_MUTEX_W(env);
4241 wsize = env->me_psize * 2;
4245 DO_WRITE(rc, fd, ptr, w2, len);
4249 } else if (len > 0) {
4255 /* Non-blocking or async handles are not supported */
4261 UNLOCK_MUTEX_W(env);
4266 wsize = txn->mt_next_pgno * env->me_psize - wsize;
4268 if (wsize > MAX_WRITE)
4272 DO_WRITE(rc, fd, ptr, w2, len);
4276 } else if (len > 0) {
4293 mdb_env_copy(MDB_env *env, const char *path)
4297 HANDLE newfd = INVALID_HANDLE_VALUE;
4299 if (env->me_flags & MDB_NOSUBDIR) {
4300 lpath = (char *)path;
4303 len += sizeof(DATANAME);
4304 lpath = malloc(len);
4307 sprintf(lpath, "%s" DATANAME, path);
4310 /* The destination path must exist, but the destination file must not.
4311 * We don't want the OS to cache the writes, since the source data is
4312 * already in the OS cache.
4315 newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
4316 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
4318 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
4320 if (newfd == INVALID_HANDLE_VALUE) {
4326 /* Set O_DIRECT if the file system supports it */
4327 if ((rc = fcntl(newfd, F_GETFL)) != -1)
4328 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
4330 #ifdef F_NOCACHE /* __APPLE__ */
4331 rc = fcntl(newfd, F_NOCACHE, 1);
4338 rc = mdb_env_copyfd(env, newfd);
4341 if (!(env->me_flags & MDB_NOSUBDIR))
4343 if (newfd != INVALID_HANDLE_VALUE)
4344 if (close(newfd) < 0 && rc == MDB_SUCCESS)
4351 mdb_env_close(MDB_env *env)
4358 VGMEMP_DESTROY(env);
4359 while ((dp = env->me_dpages) != NULL) {
4360 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
4361 env->me_dpages = dp->mp_next;
4365 mdb_env_close0(env, 0);
4369 /** Compare two items pointing at aligned size_t's */
4371 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
4373 return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
4374 *(size_t *)a->mv_data > *(size_t *)b->mv_data;
4377 /** Compare two items pointing at aligned unsigned int's */
4379 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
4381 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
4382 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
4385 /** Compare two items pointing at unsigned ints of unknown alignment.
4386 * Nodes and keys are guaranteed to be 2-byte aligned.
4389 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
4391 #if BYTE_ORDER == LITTLE_ENDIAN
4392 unsigned short *u, *c;
4395 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
4396 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
4399 } while(!x && u > (unsigned short *)a->mv_data);
4402 return memcmp(a->mv_data, b->mv_data, a->mv_size);
4406 /** Compare two items lexically */
4408 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
4415 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4421 diff = memcmp(a->mv_data, b->mv_data, len);
4422 return diff ? diff : len_diff<0 ? -1 : len_diff;
4425 /** Compare two items in reverse byte order */
4427 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
4429 const unsigned char *p1, *p2, *p1_lim;
4433 p1_lim = (const unsigned char *)a->mv_data;
4434 p1 = (const unsigned char *)a->mv_data + a->mv_size;
4435 p2 = (const unsigned char *)b->mv_data + b->mv_size;
4437 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
4443 while (p1 > p1_lim) {
4444 diff = *--p1 - *--p2;
4448 return len_diff<0 ? -1 : len_diff;
4451 /** Search for key within a page, using binary search.
4452 * Returns the smallest entry larger or equal to the key.
4453 * If exactp is non-null, stores whether the found entry was an exact match
4454 * in *exactp (1 or 0).
4455 * Updates the cursor index with the index of the found entry.
4456 * If no entry larger or equal to the key is found, returns NULL.
4459 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
4461 unsigned int i = 0, nkeys;
4464 MDB_page *mp = mc->mc_pg[mc->mc_top];
4465 MDB_node *node = NULL;
4470 nkeys = NUMKEYS(mp);
4475 COPY_PGNO(pgno, mp->mp_pgno);
4476 DPRINTF(("searching %u keys in %s %spage %"Z"u",
4477 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
4484 low = IS_LEAF(mp) ? 0 : 1;
4486 cmp = mc->mc_dbx->md_cmp;
4488 /* Branch pages have no data, so if using integer keys,
4489 * alignment is guaranteed. Use faster mdb_cmp_int.
4491 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
4492 if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
4499 nodekey.mv_size = mc->mc_db->md_pad;
4500 node = NODEPTR(mp, 0); /* fake */
4501 while (low <= high) {
4502 i = (low + high) >> 1;
4503 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
4504 rc = cmp(key, &nodekey);
4505 DPRINTF(("found leaf index %u [%s], rc = %i",
4506 i, DKEY(&nodekey), rc));
4515 while (low <= high) {
4516 i = (low + high) >> 1;
4518 node = NODEPTR(mp, i);
4519 nodekey.mv_size = NODEKSZ(node);
4520 nodekey.mv_data = NODEKEY(node);
4522 rc = cmp(key, &nodekey);
4525 DPRINTF(("found leaf index %u [%s], rc = %i",
4526 i, DKEY(&nodekey), rc));
4528 DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
4529 i, DKEY(&nodekey), NODEPGNO(node), rc));
4540 if (rc > 0) { /* Found entry is less than the key. */
4541 i++; /* Skip to get the smallest entry larger than key. */
4543 node = NODEPTR(mp, i);
4546 *exactp = (rc == 0);
4547 /* store the key index */
4548 mc->mc_ki[mc->mc_top] = i;
4550 /* There is no entry larger or equal to the key. */
4553 /* nodeptr is fake for LEAF2 */
4559 mdb_cursor_adjust(MDB_cursor *mc, func)
4563 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
4564 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
4571 /** Pop a page off the top of the cursor's stack. */
4573 mdb_cursor_pop(MDB_cursor *mc)
4577 MDB_page *top = mc->mc_pg[mc->mc_top];
4583 DPRINTF(("popped page %"Z"u off db %d cursor %p", top->mp_pgno,
4584 DDBI(mc), (void *) mc));
4588 /** Push a page onto the top of the cursor's stack. */
4590 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
4592 DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
4593 DDBI(mc), (void *) mc));
4595 if (mc->mc_snum >= CURSOR_STACK) {
4596 assert(mc->mc_snum < CURSOR_STACK);
4597 return MDB_CURSOR_FULL;
4600 mc->mc_top = mc->mc_snum++;
4601 mc->mc_pg[mc->mc_top] = mp;
4602 mc->mc_ki[mc->mc_top] = 0;
4607 /** Find the address of the page corresponding to a given page number.
4608 * @param[in] txn the transaction for this access.
4609 * @param[in] pgno the page number for the page to retrieve.
4610 * @param[out] ret address of a pointer where the page's address will be stored.
4611 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
4612 * @return 0 on success, non-zero on failure.
4615 mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
4617 MDB_env *env = txn->mt_env;
4621 if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_WRITEMAP))) {
4625 MDB_ID2L dl = tx2->mt_u.dirty_list;
4627 /* Spilled pages were dirtied in this txn and flushed
4628 * because the dirty list got full. Bring this page
4629 * back in from the map (but don't unspill it here,
4630 * leave that unless page_touch happens again).
4632 if (tx2->mt_spill_pgs) {
4633 MDB_ID pn = pgno << 1;
4634 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
4635 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
4636 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4641 unsigned x = mdb_mid2l_search(dl, pgno);
4642 if (x <= dl[0].mid && dl[x].mid == pgno) {
4648 } while ((tx2 = tx2->mt_parent) != NULL);
4651 if (pgno < txn->mt_next_pgno) {
4653 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
4655 DPRINTF(("page %"Z"u not found", pgno));
4657 return MDB_PAGE_NOTFOUND;
4667 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
4668 * The cursor is at the root page, set up the rest of it.
4671 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
4673 MDB_page *mp = mc->mc_pg[mc->mc_top];
4677 while (IS_BRANCH(mp)) {
4681 DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
4682 assert(NUMKEYS(mp) > 1);
4683 DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
4685 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
4687 if (flags & MDB_PS_LAST)
4688 i = NUMKEYS(mp) - 1;
4691 node = mdb_node_search(mc, key, &exact);
4693 i = NUMKEYS(mp) - 1;
4695 i = mc->mc_ki[mc->mc_top];
4701 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
4704 assert(i < NUMKEYS(mp));
4705 node = NODEPTR(mp, i);
4707 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4710 mc->mc_ki[mc->mc_top] = i;
4711 if ((rc = mdb_cursor_push(mc, mp)))
4714 if (flags & MDB_PS_MODIFY) {
4715 if ((rc = mdb_page_touch(mc)) != 0)
4717 mp = mc->mc_pg[mc->mc_top];
4722 DPRINTF(("internal error, index points to a %02X page!?",
4724 return MDB_CORRUPTED;
4727 DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
4728 key ? DKEY(key) : "null"));
4729 mc->mc_flags |= C_INITIALIZED;
4730 mc->mc_flags &= ~C_EOF;
4735 /** Search for the lowest key under the current branch page.
4736 * This just bypasses a NUMKEYS check in the current page
4737 * before calling mdb_page_search_root(), because the callers
4738 * are all in situations where the current page is known to
4742 mdb_page_search_lowest(MDB_cursor *mc)
4744 MDB_page *mp = mc->mc_pg[mc->mc_top];
4745 MDB_node *node = NODEPTR(mp, 0);
4748 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
4751 mc->mc_ki[mc->mc_top] = 0;
4752 if ((rc = mdb_cursor_push(mc, mp)))
4754 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
4757 /** Search for the page a given key should be in.
4758 * Push it and its parent pages on the cursor stack.
4759 * @param[in,out] mc the cursor for this operation.
4760 * @param[in] key the key to search for, or NULL for first/last page.
4761 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
4762 * are touched (updated with new page numbers).
4763 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
4764 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
4765 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
4766 * @return 0 on success, non-zero on failure.
4769 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
4774 /* Make sure the txn is still viable, then find the root from
4775 * the txn's db table and set it as the root of the cursor's stack.
4777 if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
4778 DPUTS("transaction has failed, must abort");
4781 /* Make sure we're using an up-to-date root */
4782 if (*mc->mc_dbflag & DB_STALE) {
4784 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
4785 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
4792 MDB_node *leaf = mdb_node_search(&mc2,
4793 &mc->mc_dbx->md_name, &exact);
4795 return MDB_NOTFOUND;
4796 rc = mdb_node_read(mc->mc_txn, leaf, &data);
4799 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
4801 /* The txn may not know this DBI, or another process may
4802 * have dropped and recreated the DB with other flags.
4804 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
4805 return MDB_INCOMPATIBLE;
4806 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
4808 *mc->mc_dbflag &= ~DB_STALE;
4810 root = mc->mc_db->md_root;
4812 if (root == P_INVALID) { /* Tree is empty. */
4813 DPUTS("tree is empty");
4814 return MDB_NOTFOUND;
4819 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
4820 if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
4826 DPRINTF(("db %d root page %"Z"u has flags 0x%X",
4827 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
4829 if (flags & MDB_PS_MODIFY) {
4830 if ((rc = mdb_page_touch(mc)))
4834 if (flags & MDB_PS_ROOTONLY)
4837 return mdb_page_search_root(mc, key, flags);
4841 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
4843 MDB_txn *txn = mc->mc_txn;
4844 pgno_t pg = mp->mp_pgno;
4845 unsigned x = 0, ovpages = mp->mp_pages;
4846 MDB_env *env = txn->mt_env;
4847 MDB_IDL sl = txn->mt_spill_pgs;
4848 MDB_ID pn = pg << 1;
4851 DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
4852 /* If the page is dirty or on the spill list we just acquired it,
4853 * so we should give it back to our current free list, if any.
4854 * Otherwise put it onto the list of pages we freed in this txn.
4856 * Won't create me_pghead: me_pglast must be inited along with it.
4857 * Unsupported in nested txns: They would need to hide the page
4858 * range in ancestor txns' dirty and spilled lists.
4860 if (env->me_pghead &&
4862 ((mp->mp_flags & P_DIRTY) ||
4863 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
4867 MDB_ID2 *dl, ix, iy;
4868 rc = mdb_midl_need(&env->me_pghead, ovpages);
4871 if (!(mp->mp_flags & P_DIRTY)) {
4872 /* This page is no longer spilled */
4879 /* Remove from dirty list */
4880 dl = txn->mt_u.dirty_list;
4882 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
4890 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
4891 txn->mt_flags |= MDB_TXN_ERROR;
4892 return MDB_CORRUPTED;
4895 if (!(env->me_flags & MDB_WRITEMAP))
4896 mdb_dpage_free(env, mp);
4898 /* Insert in me_pghead */
4899 mop = env->me_pghead;
4900 j = mop[0] + ovpages;
4901 for (i = mop[0]; i && mop[i] < pg; i--)
4907 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
4911 mc->mc_db->md_overflow_pages -= ovpages;
4915 /** Return the data associated with a given node.
4916 * @param[in] txn The transaction for this operation.
4917 * @param[in] leaf The node being read.
4918 * @param[out] data Updated to point to the node's data.
4919 * @return 0 on success, non-zero on failure.
4922 mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
4924 MDB_page *omp; /* overflow page */
4928 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
4929 data->mv_size = NODEDSZ(leaf);
4930 data->mv_data = NODEDATA(leaf);
4934 /* Read overflow data.
4936 data->mv_size = NODEDSZ(leaf);
4937 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
4938 if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
4939 DPRINTF(("read overflow page %"Z"u failed", pgno));
4942 data->mv_data = METADATA(omp);
4948 mdb_get(MDB_txn *txn, MDB_dbi dbi,
4949 MDB_val *key, MDB_val *data)
4958 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
4960 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
4963 if (txn->mt_flags & MDB_TXN_ERROR)
4966 if (key->mv_size > MDB_MAXKEYSIZE) {
4967 return MDB_BAD_VALSIZE;
4970 mdb_cursor_init(&mc, txn, dbi, &mx);
4971 return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
4974 /** Find a sibling for a page.
4975 * Replaces the page at the top of the cursor's stack with the
4976 * specified sibling, if one exists.
4977 * @param[in] mc The cursor for this operation.
4978 * @param[in] move_right Non-zero if the right sibling is requested,
4979 * otherwise the left sibling.
4980 * @return 0 on success, non-zero on failure.
4983 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
4989 if (mc->mc_snum < 2) {
4990 return MDB_NOTFOUND; /* root has no siblings */
4994 DPRINTF(("parent page is page %"Z"u, index %u",
4995 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
4997 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
4998 : (mc->mc_ki[mc->mc_top] == 0)) {
4999 DPRINTF(("no more keys left, moving to %s sibling",
5000 move_right ? "right" : "left"));
5001 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
5002 /* undo cursor_pop before returning */
5009 mc->mc_ki[mc->mc_top]++;
5011 mc->mc_ki[mc->mc_top]--;
5012 DPRINTF(("just moving to %s index key %u",
5013 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
5015 assert(IS_BRANCH(mc->mc_pg[mc->mc_top]));
5017 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5018 if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
5019 /* mc will be inconsistent if caller does mc_snum++ as above */
5020 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
5024 mdb_cursor_push(mc, mp);
5026 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
5031 /** Move the cursor to the next data item. */
5033 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5039 if (mc->mc_flags & C_EOF) {
5040 return MDB_NOTFOUND;
5043 assert(mc->mc_flags & C_INITIALIZED);
5045 mp = mc->mc_pg[mc->mc_top];
5047 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5048 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5049 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5050 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
5051 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
5052 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
5053 if (rc == MDB_SUCCESS)
5054 MDB_GET_KEY(leaf, key);
5059 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5060 if (op == MDB_NEXT_DUP)
5061 return MDB_NOTFOUND;
5065 DPRINTF(("cursor_next: top page is %"Z"u in cursor %p", mp->mp_pgno, (void *) mc));
5066 if (mc->mc_flags & C_DEL)
5069 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
5070 DPUTS("=====> move to next sibling page");
5071 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
5072 mc->mc_flags |= C_EOF;
5075 mp = mc->mc_pg[mc->mc_top];
5076 DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5078 mc->mc_ki[mc->mc_top]++;
5081 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5082 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5085 key->mv_size = mc->mc_db->md_pad;
5086 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5090 assert(IS_LEAF(mp));
5091 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5093 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5094 mdb_xcursor_init1(mc, leaf);
5097 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5100 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5101 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5102 if (rc != MDB_SUCCESS)
5107 MDB_GET_KEY(leaf, key);
5111 /** Move the cursor to the previous data item. */
5113 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
5119 assert(mc->mc_flags & C_INITIALIZED);
5121 mp = mc->mc_pg[mc->mc_top];
5123 if (mc->mc_db->md_flags & MDB_DUPSORT) {
5124 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5125 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5126 if (op == MDB_PREV || op == MDB_PREV_DUP) {
5127 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
5128 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
5129 if (rc == MDB_SUCCESS)
5130 MDB_GET_KEY(leaf, key);
5134 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5135 if (op == MDB_PREV_DUP)
5136 return MDB_NOTFOUND;
5141 DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p", mp->mp_pgno, (void *) mc));
5143 if (mc->mc_ki[mc->mc_top] == 0) {
5144 DPUTS("=====> move to prev sibling page");
5145 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
5148 mp = mc->mc_pg[mc->mc_top];
5149 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
5150 DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
5152 mc->mc_ki[mc->mc_top]--;
5154 mc->mc_flags &= ~C_EOF;
5156 DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
5157 mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
5160 key->mv_size = mc->mc_db->md_pad;
5161 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5165 assert(IS_LEAF(mp));
5166 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5168 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5169 mdb_xcursor_init1(mc, leaf);
5172 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5175 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5176 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5177 if (rc != MDB_SUCCESS)
5182 MDB_GET_KEY(leaf, key);
5186 /** Set the cursor on a specific data item. */
5188 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5189 MDB_cursor_op op, int *exactp)
5193 MDB_node *leaf = NULL;
5198 if (key->mv_size == 0)
5199 return MDB_BAD_VALSIZE;
5202 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5204 /* See if we're already on the right page */
5205 if (mc->mc_flags & C_INITIALIZED) {
5208 mp = mc->mc_pg[mc->mc_top];
5210 mc->mc_ki[mc->mc_top] = 0;
5211 return MDB_NOTFOUND;
5213 if (mp->mp_flags & P_LEAF2) {
5214 nodekey.mv_size = mc->mc_db->md_pad;
5215 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
5217 leaf = NODEPTR(mp, 0);
5218 MDB_GET_KEY2(leaf, nodekey);
5220 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5222 /* Probably happens rarely, but first node on the page
5223 * was the one we wanted.
5225 mc->mc_ki[mc->mc_top] = 0;
5232 unsigned int nkeys = NUMKEYS(mp);
5234 if (mp->mp_flags & P_LEAF2) {
5235 nodekey.mv_data = LEAF2KEY(mp,
5236 nkeys-1, nodekey.mv_size);
5238 leaf = NODEPTR(mp, nkeys-1);
5239 MDB_GET_KEY2(leaf, nodekey);
5241 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5243 /* last node was the one we wanted */
5244 mc->mc_ki[mc->mc_top] = nkeys-1;
5250 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
5251 /* This is definitely the right page, skip search_page */
5252 if (mp->mp_flags & P_LEAF2) {
5253 nodekey.mv_data = LEAF2KEY(mp,
5254 mc->mc_ki[mc->mc_top], nodekey.mv_size);
5256 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5257 MDB_GET_KEY2(leaf, nodekey);
5259 rc = mc->mc_dbx->md_cmp(key, &nodekey);
5261 /* current node was the one we wanted */
5271 /* If any parents have right-sibs, search.
5272 * Otherwise, there's nothing further.
5274 for (i=0; i<mc->mc_top; i++)
5276 NUMKEYS(mc->mc_pg[i])-1)
5278 if (i == mc->mc_top) {
5279 /* There are no other pages */
5280 mc->mc_ki[mc->mc_top] = nkeys;
5281 return MDB_NOTFOUND;
5285 /* There are no other pages */
5286 mc->mc_ki[mc->mc_top] = 0;
5287 if (op == MDB_SET_RANGE) {
5291 return MDB_NOTFOUND;
5295 rc = mdb_page_search(mc, key, 0);
5296 if (rc != MDB_SUCCESS)
5299 mp = mc->mc_pg[mc->mc_top];
5300 assert(IS_LEAF(mp));
5303 leaf = mdb_node_search(mc, key, exactp);
5304 if (exactp != NULL && !*exactp) {
5305 /* MDB_SET specified and not an exact match. */
5306 return MDB_NOTFOUND;
5310 DPUTS("===> inexact leaf not found, goto sibling");
5311 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
5312 return rc; /* no entries matched */
5313 mp = mc->mc_pg[mc->mc_top];
5314 assert(IS_LEAF(mp));
5315 leaf = NODEPTR(mp, 0);
5319 mc->mc_flags |= C_INITIALIZED;
5320 mc->mc_flags &= ~C_EOF;
5323 key->mv_size = mc->mc_db->md_pad;
5324 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5328 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5329 mdb_xcursor_init1(mc, leaf);
5332 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5333 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
5334 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5337 if (op == MDB_GET_BOTH) {
5343 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
5344 if (rc != MDB_SUCCESS)
5347 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
5349 if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
5351 rc = mc->mc_dbx->md_dcmp(data, &d2);
5353 if (op == MDB_GET_BOTH || rc > 0)
5354 return MDB_NOTFOUND;
5360 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5361 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5366 /* The key already matches in all other cases */
5367 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
5368 MDB_GET_KEY(leaf, key);
5369 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
5374 /** Move the cursor to the first item in the database. */
5376 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5382 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5384 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5385 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
5386 if (rc != MDB_SUCCESS)
5389 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
5391 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
5392 mc->mc_flags |= C_INITIALIZED;
5393 mc->mc_flags &= ~C_EOF;
5395 mc->mc_ki[mc->mc_top] = 0;
5397 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5398 key->mv_size = mc->mc_db->md_pad;
5399 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
5404 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5405 mdb_xcursor_init1(mc, leaf);
5406 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
5410 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5414 MDB_GET_KEY(leaf, key);
5418 /** Move the cursor to the last item in the database. */
5420 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
5426 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
5428 if (!(mc->mc_flags & C_EOF)) {
5430 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
5431 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
5432 if (rc != MDB_SUCCESS)
5435 assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
5438 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
5439 mc->mc_flags |= C_INITIALIZED|C_EOF;
5440 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5442 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5443 key->mv_size = mc->mc_db->md_pad;
5444 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
5449 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5450 mdb_xcursor_init1(mc, leaf);
5451 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
5455 if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
5460 MDB_GET_KEY(leaf, key);
5465 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5470 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
5474 if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
5478 case MDB_GET_CURRENT:
5479 if (!(mc->mc_flags & C_INITIALIZED)) {
5482 MDB_page *mp = mc->mc_pg[mc->mc_top];
5483 int nkeys = NUMKEYS(mp);
5484 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
5485 mc->mc_ki[mc->mc_top] = nkeys;
5491 key->mv_size = mc->mc_db->md_pad;
5492 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
5494 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
5495 MDB_GET_KEY(leaf, key);
5497 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5498 if (mc->mc_flags & C_DEL)
5499 mdb_xcursor_init1(mc, leaf);
5500 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
5502 rc = mdb_node_read(mc->mc_txn, leaf, data);
5509 case MDB_GET_BOTH_RANGE:
5514 if (mc->mc_xcursor == NULL) {
5515 rc = MDB_INCOMPATIBLE;
5524 } else if (key->mv_size > MDB_MAXKEYSIZE) {
5525 rc = MDB_BAD_VALSIZE;
5526 } else if (op == MDB_SET_RANGE)
5527 rc = mdb_cursor_set(mc, key, data, op, NULL);
5529 rc = mdb_cursor_set(mc, key, data, op, &exact);
5531 case MDB_GET_MULTIPLE:
5532 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5536 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5537 rc = MDB_INCOMPATIBLE;
5541 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
5542 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
5545 case MDB_NEXT_MULTIPLE:
5550 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5551 rc = MDB_INCOMPATIBLE;
5554 if (!(mc->mc_flags & C_INITIALIZED))
5555 rc = mdb_cursor_first(mc, key, data);
5557 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
5558 if (rc == MDB_SUCCESS) {
5559 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
5562 mx = &mc->mc_xcursor->mx_cursor;
5563 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
5565 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
5566 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
5574 case MDB_NEXT_NODUP:
5575 if (!(mc->mc_flags & C_INITIALIZED))
5576 rc = mdb_cursor_first(mc, key, data);
5578 rc = mdb_cursor_next(mc, key, data, op);
5582 case MDB_PREV_NODUP:
5583 if (!(mc->mc_flags & C_INITIALIZED)) {
5584 rc = mdb_cursor_last(mc, key, data);
5587 mc->mc_flags |= C_INITIALIZED;
5588 mc->mc_ki[mc->mc_top]++;
5590 rc = mdb_cursor_prev(mc, key, data, op);
5593 rc = mdb_cursor_first(mc, key, data);
5596 mfunc = mdb_cursor_first;
5598 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
5602 if (mc->mc_xcursor == NULL) {
5603 rc = MDB_INCOMPATIBLE;
5606 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
5610 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
5613 rc = mdb_cursor_last(mc, key, data);
5616 mfunc = mdb_cursor_last;
5619 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
5624 if (mc->mc_flags & C_DEL)
5625 mc->mc_flags ^= C_DEL;
5630 /** Touch all the pages in the cursor stack. Set mc_top.
5631 * Makes sure all the pages are writable, before attempting a write operation.
5632 * @param[in] mc The cursor to operate on.
5635 mdb_cursor_touch(MDB_cursor *mc)
5637 int rc = MDB_SUCCESS;
5639 if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
5642 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
5643 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
5646 *mc->mc_dbflag |= DB_DIRTY;
5651 rc = mdb_page_touch(mc);
5652 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
5653 mc->mc_top = mc->mc_snum-1;
5658 /** Do not spill pages to disk if txn is getting full, may fail instead */
5659 #define MDB_NOSPILL 0x8000
5662 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
5665 enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
5666 MDB_env *env = mc->mc_txn->mt_env;
5667 MDB_node *leaf = NULL;
5668 MDB_val xdata, *rdata, dkey;
5670 int do_sub = 0, insert = 0;
5671 unsigned int mcount = 0, dcount = 0, nospill;
5674 char dbuf[MDB_MAXKEYSIZE+1];
5675 unsigned int nflags;
5678 /* Check this first so counter will always be zero on any
5681 if (flags & MDB_MULTIPLE) {
5682 dcount = data[1].mv_size;
5683 data[1].mv_size = 0;
5684 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
5685 return MDB_INCOMPATIBLE;
5688 nospill = flags & MDB_NOSPILL;
5689 flags &= ~MDB_NOSPILL;
5691 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
5692 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
5694 if (flags != MDB_CURRENT && (key->mv_size == 0 || key->mv_size > MDB_MAXKEYSIZE))
5695 return MDB_BAD_VALSIZE;
5697 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT) && data->mv_size > MDB_MAXKEYSIZE)
5698 return MDB_BAD_VALSIZE;
5700 #if SIZE_MAX > MAXDATASIZE
5701 if (data->mv_size > MAXDATASIZE)
5702 return MDB_BAD_VALSIZE;
5705 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
5706 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
5710 if (flags == MDB_CURRENT) {
5711 if (!(mc->mc_flags & C_INITIALIZED))
5714 } else if (mc->mc_db->md_root == P_INVALID) {
5715 /* new database, cursor has nothing to point to */
5718 mc->mc_flags &= ~C_INITIALIZED;
5723 if (flags & MDB_APPEND) {
5725 rc = mdb_cursor_last(mc, &k2, &d2);
5727 rc = mc->mc_dbx->md_cmp(key, &k2);
5730 mc->mc_ki[mc->mc_top]++;
5732 /* new key is <= last key */
5737 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
5739 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
5740 DPRINTF(("duplicate key [%s]", DKEY(key)));
5742 return MDB_KEYEXIST;
5744 if (rc && rc != MDB_NOTFOUND)
5748 if (mc->mc_flags & C_DEL)
5749 mc->mc_flags ^= C_DEL;
5751 /* Cursor is positioned, check for room in the dirty list */
5753 if (flags & MDB_MULTIPLE) {
5755 xdata.mv_size = data->mv_size * dcount;
5759 if ((rc2 = mdb_page_spill(mc, key, rdata)))
5763 if (rc == MDB_NO_ROOT) {
5765 /* new database, write a root leaf page */
5766 DPUTS("allocating new root leaf page");
5767 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
5770 mdb_cursor_push(mc, np);
5771 mc->mc_db->md_root = np->mp_pgno;
5772 mc->mc_db->md_depth++;
5773 *mc->mc_dbflag |= DB_DIRTY;
5774 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
5776 np->mp_flags |= P_LEAF2;
5777 mc->mc_flags |= C_INITIALIZED;
5779 /* make sure all cursor pages are writable */
5780 rc2 = mdb_cursor_touch(mc);
5785 /* The key already exists */
5786 if (rc == MDB_SUCCESS) {
5790 /* there's only a key anyway, so this is a no-op */
5791 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
5792 unsigned int ksize = mc->mc_db->md_pad;
5793 if (key->mv_size != ksize)
5794 return MDB_BAD_VALSIZE;
5795 if (flags == MDB_CURRENT) {
5796 char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
5797 memcpy(ptr, key->mv_data, ksize);
5803 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
5804 olddata.mv_size = NODEDSZ(leaf);
5805 olddata.mv_data = NODEDATA(leaf);
5808 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
5809 mp = fp = xdata.mv_data = env->me_pbuf;
5810 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
5812 /* Was a single item before, must convert now */
5813 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
5814 /* Just overwrite the current item */
5815 if (flags == MDB_CURRENT)
5819 #if UINT_MAX < SIZE_MAX
5820 if (mc->mc_dbx->md_dcmp == mdb_cmp_int && dkey.mv_size == sizeof(size_t))
5821 #ifdef MISALIGNED_OK
5822 mc->mc_dbx->md_dcmp = mdb_cmp_long;
5824 mc->mc_dbx->md_dcmp = mdb_cmp_cint;
5827 /* if data matches, skip it */
5828 if (!mc->mc_dbx->md_dcmp(data, &dkey)) {
5829 if (flags & MDB_NODUPDATA)
5831 else if (flags & MDB_MULTIPLE)
5838 /* create a fake page for the dup items */
5839 memcpy(dbuf, dkey.mv_data, dkey.mv_size);
5840 dkey.mv_data = dbuf;
5841 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
5842 fp->mp_lower = PAGEHDRSZ;
5843 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
5844 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5845 fp->mp_flags |= P_LEAF2;
5846 fp->mp_pad = data->mv_size;
5847 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
5849 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
5850 (dkey.mv_size & 1) + (data->mv_size & 1);
5852 fp->mp_upper = xdata.mv_size;
5853 } else if (leaf->mn_flags & F_SUBDATA) {
5854 /* Data is on sub-DB, just store it */
5855 flags |= F_DUPDATA|F_SUBDATA;
5858 /* See if we need to convert from fake page to subDB */
5859 unsigned int offset;
5863 fp = olddata.mv_data;
5866 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
5867 offset = NODESIZE + sizeof(indx_t) + data->mv_size;
5868 offset += offset & 1;
5871 offset = fp->mp_pad;
5872 if (SIZELEFT(fp) < offset) {
5873 offset *= 4; /* space for 4 more */
5876 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
5878 fp->mp_flags |= P_DIRTY;
5879 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
5880 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
5884 fp_flags = fp->mp_flags;
5885 xdata.mv_size = olddata.mv_size + offset;
5886 if (NODESIZE + sizeof(indx_t) + NODEKSZ(leaf) + xdata.mv_size
5887 >= env->me_nodemax) {
5888 /* yes, convert it */
5889 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
5890 dummy.md_pad = fp->mp_pad;
5891 dummy.md_flags = MDB_DUPFIXED;
5892 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
5893 dummy.md_flags |= MDB_INTEGERKEY;
5899 dummy.md_branch_pages = 0;
5900 dummy.md_leaf_pages = 1;
5901 dummy.md_overflow_pages = 0;
5902 dummy.md_entries = NUMKEYS(fp);
5903 xdata.mv_size = sizeof(MDB_db);
5904 xdata.mv_data = &dummy;
5905 if ((rc = mdb_page_alloc(mc, 1, &mp)))
5907 offset = env->me_psize - olddata.mv_size;
5908 flags |= F_DUPDATA|F_SUBDATA;
5909 dummy.md_root = mp->mp_pgno;
5910 fp_flags &= ~P_SUBP;
5912 mp->mp_flags = fp_flags | P_DIRTY;
5913 mp->mp_pad = fp->mp_pad;
5914 mp->mp_lower = fp->mp_lower;
5915 mp->mp_upper = fp->mp_upper + offset;
5917 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
5919 memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper,
5920 olddata.mv_size - fp->mp_upper);
5921 for (i=0; i<NUMKEYS(fp); i++)
5922 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
5929 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
5933 /* overflow page overwrites need special handling */
5934 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
5937 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
5939 memcpy(&pg, olddata.mv_data, sizeof(pg));
5940 if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
5942 ovpages = omp->mp_pages;
5944 /* Is the ov page large enough? */
5945 if (ovpages >= dpages) {
5946 if (!(omp->mp_flags & P_DIRTY) &&
5947 (level || (env->me_flags & MDB_WRITEMAP)))
5949 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
5952 level = 0; /* dirty in this txn or clean */
5955 if (omp->mp_flags & P_DIRTY) {
5956 /* yes, overwrite it. Note in this case we don't
5957 * bother to try shrinking the page if the new data
5958 * is smaller than the overflow threshold.
5961 /* It is writable only in a parent txn */
5962 size_t sz = (size_t) env->me_psize * ovpages, off;
5963 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
5969 mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
5970 if (!(flags & MDB_RESERVE)) {
5971 /* Copy end of page, adjusting alignment so
5972 * compiler may copy words instead of bytes.
5974 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
5975 memcpy((size_t *)((char *)np + off),
5976 (size_t *)((char *)omp + off), sz - off);
5979 memcpy(np, omp, sz); /* Copy beginning of page */
5982 SETDSZ(leaf, data->mv_size);
5983 if (F_ISSET(flags, MDB_RESERVE))
5984 data->mv_data = METADATA(omp);
5986 memcpy(METADATA(omp), data->mv_data, data->mv_size);
5990 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
5992 } else if (data->mv_size == olddata.mv_size) {
5993 /* same size, just replace it. Note that we could
5994 * also reuse this node if the new data is smaller,
5995 * but instead we opt to shrink the node in that case.
5997 if (F_ISSET(flags, MDB_RESERVE))
5998 data->mv_data = olddata.mv_data;
5999 else if (data->mv_size)
6000 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
6002 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
6005 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
6006 mc->mc_db->md_entries--;
6008 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
6015 nflags = flags & NODE_ADD_FLAGS;
6016 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
6017 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
6018 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
6019 nflags &= ~MDB_APPEND;
6021 nflags |= MDB_SPLIT_REPLACE;
6022 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
6024 /* There is room already in this leaf page. */
6025 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
6026 if (rc == 0 && !do_sub && insert) {
6027 /* Adjust other cursors pointing to mp */
6028 MDB_cursor *m2, *m3;
6029 MDB_dbi dbi = mc->mc_dbi;
6030 unsigned i = mc->mc_top;
6031 MDB_page *mp = mc->mc_pg[i];
6033 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6034 if (mc->mc_flags & C_SUB)
6035 m3 = &m2->mc_xcursor->mx_cursor;
6038 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
6039 if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
6046 if (rc != MDB_SUCCESS)
6047 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6049 /* Now store the actual data in the child DB. Note that we're
6050 * storing the user data in the keys field, so there are strict
6051 * size limits on dupdata. The actual data fields of the child
6052 * DB are all zero size.
6059 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6060 if (flags & MDB_CURRENT) {
6061 xflags = MDB_CURRENT|MDB_NOSPILL;
6063 mdb_xcursor_init1(mc, leaf);
6064 xflags = (flags & MDB_NODUPDATA) ?
6065 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
6067 /* converted, write the original data first */
6069 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
6073 /* Adjust other cursors pointing to mp */
6075 unsigned i = mc->mc_top;
6076 MDB_page *mp = mc->mc_pg[i];
6078 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6079 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6080 if (!(m2->mc_flags & C_INITIALIZED)) continue;
6081 if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
6082 mdb_xcursor_init1(m2, leaf);
6086 /* we've done our job */
6089 if (flags & MDB_APPENDDUP)
6090 xflags |= MDB_APPEND;
6091 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
6092 if (flags & F_SUBDATA) {
6093 void *db = NODEDATA(leaf);
6094 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6097 /* sub-writes might have failed so check rc again.
6098 * Don't increment count if we just replaced an existing item.
6100 if (!rc && !(flags & MDB_CURRENT))
6101 mc->mc_db->md_entries++;
6102 if (flags & MDB_MULTIPLE) {
6106 /* let caller know how many succeeded, if any */
6107 data[1].mv_size = mcount;
6108 if (mcount < dcount) {
6109 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
6116 /* If we succeeded and the key didn't exist before, make sure
6117 * the cursor is marked valid.
6120 mc->mc_flags |= C_INITIALIZED;
6125 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
6131 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
6132 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
6134 if (!(mc->mc_flags & C_INITIALIZED))
6137 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6138 return MDB_NOTFOUND;
6140 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
6143 rc = mdb_cursor_touch(mc);
6147 mp = mc->mc_pg[mc->mc_top];
6148 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6150 if (!IS_LEAF2(mp) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6151 if (!(flags & MDB_NODUPDATA)) {
6152 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
6153 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6155 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
6156 /* If sub-DB still has entries, we're done */
6157 if (mc->mc_xcursor->mx_db.md_entries) {
6158 if (leaf->mn_flags & F_SUBDATA) {
6159 /* update subDB info */
6160 void *db = NODEDATA(leaf);
6161 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
6164 /* shrink fake page */
6165 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
6166 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6167 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6168 /* fix other sub-DB cursors pointed at this fake page */
6169 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
6170 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
6171 if (m2->mc_pg[mc->mc_top] == mp &&
6172 m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
6173 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
6176 mc->mc_db->md_entries--;
6177 mc->mc_flags |= C_DEL;
6180 /* otherwise fall thru and delete the sub-DB */
6183 if (leaf->mn_flags & F_SUBDATA) {
6184 /* add all the child DB's pages to the free list */
6185 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
6186 if (rc == MDB_SUCCESS) {
6187 mc->mc_db->md_entries -=
6188 mc->mc_xcursor->mx_db.md_entries;
6193 return mdb_cursor_del0(mc, leaf);
6196 /** Allocate and initialize new pages for a database.
6197 * @param[in] mc a cursor on the database being added to.
6198 * @param[in] flags flags defining what type of page is being allocated.
6199 * @param[in] num the number of pages to allocate. This is usually 1,
6200 * unless allocating overflow pages for a large record.
6201 * @param[out] mp Address of a page, or NULL on failure.
6202 * @return 0 on success, non-zero on failure.
6205 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
6210 if ((rc = mdb_page_alloc(mc, num, &np)))
6212 DPRINTF(("allocated new mpage %"Z"u, page size %u",
6213 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
6214 np->mp_flags = flags | P_DIRTY;
6215 np->mp_lower = PAGEHDRSZ;
6216 np->mp_upper = mc->mc_txn->mt_env->me_psize;
6219 mc->mc_db->md_branch_pages++;
6220 else if (IS_LEAF(np))
6221 mc->mc_db->md_leaf_pages++;
6222 else if (IS_OVERFLOW(np)) {
6223 mc->mc_db->md_overflow_pages += num;
6231 /** Calculate the size of a leaf node.
6232 * The size depends on the environment's page size; if a data item
6233 * is too large it will be put onto an overflow page and the node
6234 * size will only include the key and not the data. Sizes are always
6235 * rounded up to an even number of bytes, to guarantee 2-byte alignment
6236 * of the #MDB_node headers.
6237 * @param[in] env The environment handle.
6238 * @param[in] key The key for the node.
6239 * @param[in] data The data for the node.
6240 * @return The number of bytes needed to store the node.
6243 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
6247 sz = LEAFSIZE(key, data);
6248 if (sz >= env->me_nodemax) {
6249 /* put on overflow page */
6250 sz -= data->mv_size - sizeof(pgno_t);
6254 return sz + sizeof(indx_t);
6257 /** Calculate the size of a branch node.
6258 * The size should depend on the environment's page size but since
6259 * we currently don't support spilling large keys onto overflow
6260 * pages, it's simply the size of the #MDB_node header plus the
6261 * size of the key. Sizes are always rounded up to an even number
6262 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
6263 * @param[in] env The environment handle.
6264 * @param[in] key The key for the node.
6265 * @return The number of bytes needed to store the node.
6268 mdb_branch_size(MDB_env *env, MDB_val *key)
6273 if (sz >= env->me_nodemax) {
6274 /* put on overflow page */
6275 /* not implemented */
6276 /* sz -= key->size - sizeof(pgno_t); */
6279 return sz + sizeof(indx_t);
6282 /** Add a node to the page pointed to by the cursor.
6283 * @param[in] mc The cursor for this operation.
6284 * @param[in] indx The index on the page where the new node should be added.
6285 * @param[in] key The key for the new node.
6286 * @param[in] data The data for the new node, if any.
6287 * @param[in] pgno The page number, if adding a branch node.
6288 * @param[in] flags Flags for the node.
6289 * @return 0 on success, non-zero on failure. Possible errors are:
6291 * <li>ENOMEM - failed to allocate overflow pages for the node.
6292 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
6293 * should never happen since all callers already calculate the
6294 * page's free space before calling this function.
6298 mdb_node_add(MDB_cursor *mc, indx_t indx,
6299 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
6302 size_t node_size = NODESIZE;
6306 MDB_page *mp = mc->mc_pg[mc->mc_top];
6307 MDB_page *ofp = NULL; /* overflow page */
6310 assert(mp->mp_upper >= mp->mp_lower);
6312 DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
6313 IS_LEAF(mp) ? "leaf" : "branch",
6314 IS_SUBP(mp) ? "sub-" : "",
6315 mp->mp_pgno, indx, data ? data->mv_size : 0,
6316 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
6319 /* Move higher keys up one slot. */
6320 int ksize = mc->mc_db->md_pad, dif;
6321 char *ptr = LEAF2KEY(mp, indx, ksize);
6322 dif = NUMKEYS(mp) - indx;
6324 memmove(ptr+ksize, ptr, dif*ksize);
6325 /* insert new key */
6326 memcpy(ptr, key->mv_data, ksize);
6328 /* Just using these for counting */
6329 mp->mp_lower += sizeof(indx_t);
6330 mp->mp_upper -= ksize - sizeof(indx_t);
6334 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
6336 node_size += key->mv_size;
6339 if (F_ISSET(flags, F_BIGDATA)) {
6340 /* Data already on overflow page. */
6341 node_size += sizeof(pgno_t);
6342 } else if (node_size + data->mv_size >= mc->mc_txn->mt_env->me_nodemax) {
6343 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
6345 /* Put data on overflow page. */
6346 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
6347 data->mv_size, node_size+data->mv_size));
6348 node_size += sizeof(pgno_t) + (node_size & 1);
6349 if ((ssize_t)node_size > room)
6351 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
6353 DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
6357 node_size += data->mv_size;
6360 node_size += node_size & 1;
6361 if ((ssize_t)node_size > room)
6365 /* Move higher pointers up one slot. */
6366 for (i = NUMKEYS(mp); i > indx; i--)
6367 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
6369 /* Adjust free space offsets. */
6370 ofs = mp->mp_upper - node_size;
6371 assert(ofs >= mp->mp_lower + sizeof(indx_t));
6372 mp->mp_ptrs[indx] = ofs;
6374 mp->mp_lower += sizeof(indx_t);
6376 /* Write the node data. */
6377 node = NODEPTR(mp, indx);
6378 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
6379 node->mn_flags = flags;
6381 SETDSZ(node,data->mv_size);
6386 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
6391 if (F_ISSET(flags, F_BIGDATA))
6392 memcpy(node->mn_data + key->mv_size, data->mv_data,
6394 else if (F_ISSET(flags, MDB_RESERVE))
6395 data->mv_data = node->mn_data + key->mv_size;
6397 memcpy(node->mn_data + key->mv_size, data->mv_data,
6400 memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
6402 if (F_ISSET(flags, MDB_RESERVE))
6403 data->mv_data = METADATA(ofp);
6405 memcpy(METADATA(ofp), data->mv_data, data->mv_size);
6412 DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
6413 mp->mp_pgno, NUMKEYS(mp)));
6414 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
6415 DPRINTF(("node size = %"Z"u", node_size));
6416 return MDB_PAGE_FULL;
6419 /** Delete the specified node from a page.
6420 * @param[in] mp The page to operate on.
6421 * @param[in] indx The index of the node to delete.
6422 * @param[in] ksize The size of a node. Only used if the page is
6423 * part of a #MDB_DUPFIXED database.
6426 mdb_node_del(MDB_page *mp, indx_t indx, int ksize)
6429 indx_t i, j, numkeys, ptr;
6436 COPY_PGNO(pgno, mp->mp_pgno);
6437 DPRINTF(("delete node %u on %s page %"Z"u", indx,
6438 IS_LEAF(mp) ? "leaf" : "branch", pgno));
6441 assert(indx < NUMKEYS(mp));
6444 int x = NUMKEYS(mp) - 1 - indx;
6445 base = LEAF2KEY(mp, indx, ksize);
6447 memmove(base, base + ksize, x * ksize);
6448 mp->mp_lower -= sizeof(indx_t);
6449 mp->mp_upper += ksize - sizeof(indx_t);
6453 node = NODEPTR(mp, indx);
6454 sz = NODESIZE + node->mn_ksize;
6456 if (F_ISSET(node->mn_flags, F_BIGDATA))
6457 sz += sizeof(pgno_t);
6459 sz += NODEDSZ(node);
6463 ptr = mp->mp_ptrs[indx];
6464 numkeys = NUMKEYS(mp);
6465 for (i = j = 0; i < numkeys; i++) {
6467 mp->mp_ptrs[j] = mp->mp_ptrs[i];
6468 if (mp->mp_ptrs[i] < ptr)
6469 mp->mp_ptrs[j] += sz;
6474 base = (char *)mp + mp->mp_upper;
6475 memmove(base + sz, base, ptr - mp->mp_upper);
6477 mp->mp_lower -= sizeof(indx_t);
6481 /** Compact the main page after deleting a node on a subpage.
6482 * @param[in] mp The main page to operate on.
6483 * @param[in] indx The index of the subpage on the main page.
6486 mdb_node_shrink(MDB_page *mp, indx_t indx)
6493 indx_t i, numkeys, ptr;
6495 node = NODEPTR(mp, indx);
6496 sp = (MDB_page *)NODEDATA(node);
6497 osize = NODEDSZ(node);
6499 delta = sp->mp_upper - sp->mp_lower;
6500 SETDSZ(node, osize - delta);
6501 xp = (MDB_page *)((char *)sp + delta);
6503 /* shift subpage upward */
6505 nsize = NUMKEYS(sp) * sp->mp_pad;
6506 memmove(METADATA(xp), METADATA(sp), nsize);
6509 nsize = osize - sp->mp_upper;
6510 numkeys = NUMKEYS(sp);
6511 for (i=numkeys-1; i>=0; i--)
6512 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
6514 xp->mp_upper = sp->mp_lower;
6515 xp->mp_lower = sp->mp_lower;
6516 xp->mp_flags = sp->mp_flags;
6517 xp->mp_pad = sp->mp_pad;
6518 COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
6520 /* shift lower nodes upward */
6521 ptr = mp->mp_ptrs[indx];
6522 numkeys = NUMKEYS(mp);
6523 for (i = 0; i < numkeys; i++) {
6524 if (mp->mp_ptrs[i] <= ptr)
6525 mp->mp_ptrs[i] += delta;
6528 base = (char *)mp + mp->mp_upper;
6529 memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
6530 mp->mp_upper += delta;
6533 /** Initial setup of a sorted-dups cursor.
6534 * Sorted duplicates are implemented as a sub-database for the given key.
6535 * The duplicate data items are actually keys of the sub-database.
6536 * Operations on the duplicate data items are performed using a sub-cursor
6537 * initialized when the sub-database is first accessed. This function does
6538 * the preliminary setup of the sub-cursor, filling in the fields that
6539 * depend only on the parent DB.
6540 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6543 mdb_xcursor_init0(MDB_cursor *mc)
6545 MDB_xcursor *mx = mc->mc_xcursor;
6547 mx->mx_cursor.mc_xcursor = NULL;
6548 mx->mx_cursor.mc_txn = mc->mc_txn;
6549 mx->mx_cursor.mc_db = &mx->mx_db;
6550 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
6551 mx->mx_cursor.mc_dbi = mc->mc_dbi;
6552 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
6553 mx->mx_cursor.mc_snum = 0;
6554 mx->mx_cursor.mc_top = 0;
6555 mx->mx_cursor.mc_flags = C_SUB;
6556 mx->mx_dbx.md_name.mv_size = 0;
6557 mx->mx_dbx.md_name.mv_data = NULL;
6558 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
6559 mx->mx_dbx.md_dcmp = NULL;
6560 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
6563 /** Final setup of a sorted-dups cursor.
6564 * Sets up the fields that depend on the data from the main cursor.
6565 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
6566 * @param[in] node The data containing the #MDB_db record for the
6567 * sorted-dup database.
6570 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
6572 MDB_xcursor *mx = mc->mc_xcursor;
6574 if (node->mn_flags & F_SUBDATA) {
6575 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
6576 mx->mx_cursor.mc_pg[0] = 0;
6577 mx->mx_cursor.mc_snum = 0;
6578 mx->mx_cursor.mc_top = 0;
6579 mx->mx_cursor.mc_flags = C_SUB;
6581 MDB_page *fp = NODEDATA(node);
6582 mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
6583 mx->mx_db.md_flags = 0;
6584 mx->mx_db.md_depth = 1;
6585 mx->mx_db.md_branch_pages = 0;
6586 mx->mx_db.md_leaf_pages = 1;
6587 mx->mx_db.md_overflow_pages = 0;
6588 mx->mx_db.md_entries = NUMKEYS(fp);
6589 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
6590 mx->mx_cursor.mc_snum = 1;
6591 mx->mx_cursor.mc_top = 0;
6592 mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
6593 mx->mx_cursor.mc_pg[0] = fp;
6594 mx->mx_cursor.mc_ki[0] = 0;
6595 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
6596 mx->mx_db.md_flags = MDB_DUPFIXED;
6597 mx->mx_db.md_pad = fp->mp_pad;
6598 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
6599 mx->mx_db.md_flags |= MDB_INTEGERKEY;
6602 DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
6603 mx->mx_db.md_root));
6604 mx->mx_dbflag = DB_VALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
6605 #if UINT_MAX < SIZE_MAX
6606 if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
6607 #ifdef MISALIGNED_OK
6608 mx->mx_dbx.md_cmp = mdb_cmp_long;
6610 mx->mx_dbx.md_cmp = mdb_cmp_cint;
6615 /** Initialize a cursor for a given transaction and database. */
6617 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
6620 mc->mc_backup = NULL;
6623 mc->mc_db = &txn->mt_dbs[dbi];
6624 mc->mc_dbx = &txn->mt_dbxs[dbi];
6625 mc->mc_dbflag = &txn->mt_dbflags[dbi];
6630 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
6632 mc->mc_xcursor = mx;
6633 mdb_xcursor_init0(mc);
6635 mc->mc_xcursor = NULL;
6637 if (*mc->mc_dbflag & DB_STALE) {
6638 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
6643 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
6646 size_t size = sizeof(MDB_cursor);
6648 if (txn == NULL || ret == NULL || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
6651 if (txn->mt_flags & MDB_TXN_ERROR)
6654 /* Allow read access to the freelist */
6655 if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
6658 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
6659 size += sizeof(MDB_xcursor);
6661 if ((mc = malloc(size)) != NULL) {
6662 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
6663 if (txn->mt_cursors) {
6664 mc->mc_next = txn->mt_cursors[dbi];
6665 txn->mt_cursors[dbi] = mc;
6666 mc->mc_flags |= C_UNTRACK;
6678 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
6680 if (txn == NULL || mc == NULL || mc->mc_dbi >= txn->mt_numdbs)
6683 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
6686 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
6690 /* Return the count of duplicate data items for the current key */
6692 mdb_cursor_count(MDB_cursor *mc, size_t *countp)
6696 if (mc == NULL || countp == NULL)
6699 if (mc->mc_xcursor == NULL)
6700 return MDB_INCOMPATIBLE;
6702 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6703 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6706 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
6709 *countp = mc->mc_xcursor->mx_db.md_entries;
6715 mdb_cursor_close(MDB_cursor *mc)
6717 if (mc && !mc->mc_backup) {
6718 /* remove from txn, if tracked */
6719 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
6720 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
6721 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
6723 *prev = mc->mc_next;
6730 mdb_cursor_txn(MDB_cursor *mc)
6732 if (!mc) return NULL;
6737 mdb_cursor_dbi(MDB_cursor *mc)
6743 /** Replace the key for a node with a new key.
6744 * @param[in] mc Cursor pointing to the node to operate on.
6745 * @param[in] key The new key to use.
6746 * @return 0 on success, non-zero on failure.
6749 mdb_update_key(MDB_cursor *mc, MDB_val *key)
6756 indx_t ptr, i, numkeys, indx;
6759 indx = mc->mc_ki[mc->mc_top];
6760 mp = mc->mc_pg[mc->mc_top];
6761 node = NODEPTR(mp, indx);
6762 ptr = mp->mp_ptrs[indx];
6766 char kbuf2[(MDB_MAXKEYSIZE*2+1)];
6767 k2.mv_data = NODEKEY(node);
6768 k2.mv_size = node->mn_ksize;
6769 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
6771 mdb_dkey(&k2, kbuf2),
6777 delta0 = delta = key->mv_size - node->mn_ksize;
6779 /* Must be 2-byte aligned. If new key is
6780 * shorter by 1, the shift will be skipped.
6782 delta += (delta & 1);
6784 if (delta > 0 && SIZELEFT(mp) < delta) {
6786 /* not enough space left, do a delete and split */
6787 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
6788 pgno = NODEPGNO(node);
6789 mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0);
6790 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
6793 numkeys = NUMKEYS(mp);
6794 for (i = 0; i < numkeys; i++) {
6795 if (mp->mp_ptrs[i] <= ptr)
6796 mp->mp_ptrs[i] -= delta;
6799 base = (char *)mp + mp->mp_upper;
6800 len = ptr - mp->mp_upper + NODESIZE;
6801 memmove(base - delta, base, len);
6802 mp->mp_upper -= delta;
6804 node = NODEPTR(mp, indx);
6807 /* But even if no shift was needed, update ksize */
6809 node->mn_ksize = key->mv_size;
6812 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
6818 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
6820 /** Move a node from csrc to cdst.
6823 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
6830 unsigned short flags;
6834 /* Mark src and dst as dirty. */
6835 if ((rc = mdb_page_touch(csrc)) ||
6836 (rc = mdb_page_touch(cdst)))
6839 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6840 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */
6841 key.mv_size = csrc->mc_db->md_pad;
6842 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
6844 data.mv_data = NULL;
6848 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
6849 assert(!((size_t)srcnode&1));
6850 srcpg = NODEPGNO(srcnode);
6851 flags = srcnode->mn_flags;
6852 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
6853 unsigned int snum = csrc->mc_snum;
6855 /* must find the lowest key below src */
6856 mdb_page_search_lowest(csrc);
6857 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6858 key.mv_size = csrc->mc_db->md_pad;
6859 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
6861 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
6862 key.mv_size = NODEKSZ(s2);
6863 key.mv_data = NODEKEY(s2);
6865 csrc->mc_snum = snum--;
6866 csrc->mc_top = snum;
6868 key.mv_size = NODEKSZ(srcnode);
6869 key.mv_data = NODEKEY(srcnode);
6871 data.mv_size = NODEDSZ(srcnode);
6872 data.mv_data = NODEDATA(srcnode);
6874 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
6875 unsigned int snum = cdst->mc_snum;
6878 /* must find the lowest key below dst */
6879 mdb_page_search_lowest(cdst);
6880 if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
6881 bkey.mv_size = cdst->mc_db->md_pad;
6882 bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
6884 s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
6885 bkey.mv_size = NODEKSZ(s2);
6886 bkey.mv_data = NODEKEY(s2);
6888 cdst->mc_snum = snum--;
6889 cdst->mc_top = snum;
6890 mdb_cursor_copy(cdst, &mn);
6892 rc = mdb_update_key(&mn, &bkey);
6897 DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
6898 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
6899 csrc->mc_ki[csrc->mc_top],
6901 csrc->mc_pg[csrc->mc_top]->mp_pgno,
6902 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
6904 /* Add the node to the destination page.
6906 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
6907 if (rc != MDB_SUCCESS)
6910 /* Delete the node from the source page.
6912 mdb_node_del(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
6915 /* Adjust other cursors pointing to mp */
6916 MDB_cursor *m2, *m3;
6917 MDB_dbi dbi = csrc->mc_dbi;
6918 MDB_page *mp = csrc->mc_pg[csrc->mc_top];
6920 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
6921 if (csrc->mc_flags & C_SUB)
6922 m3 = &m2->mc_xcursor->mx_cursor;
6925 if (m3 == csrc) continue;
6926 if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
6927 csrc->mc_ki[csrc->mc_top]) {
6928 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
6929 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
6934 /* Update the parent separators.
6936 if (csrc->mc_ki[csrc->mc_top] == 0) {
6937 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
6938 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6939 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
6941 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
6942 key.mv_size = NODEKSZ(srcnode);
6943 key.mv_data = NODEKEY(srcnode);
6945 DPRINTF(("update separator for source page %"Z"u to [%s]",
6946 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
6947 mdb_cursor_copy(csrc, &mn);
6950 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
6953 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
6955 indx_t ix = csrc->mc_ki[csrc->mc_top];
6956 nullkey.mv_size = 0;
6957 csrc->mc_ki[csrc->mc_top] = 0;
6958 rc = mdb_update_key(csrc, &nullkey);
6959 csrc->mc_ki[csrc->mc_top] = ix;
6960 assert(rc == MDB_SUCCESS);
6964 if (cdst->mc_ki[cdst->mc_top] == 0) {
6965 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
6966 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
6967 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
6969 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
6970 key.mv_size = NODEKSZ(srcnode);
6971 key.mv_data = NODEKEY(srcnode);
6973 DPRINTF(("update separator for destination page %"Z"u to [%s]",
6974 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
6975 mdb_cursor_copy(cdst, &mn);
6978 if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
6981 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
6983 indx_t ix = cdst->mc_ki[cdst->mc_top];
6984 nullkey.mv_size = 0;
6985 cdst->mc_ki[cdst->mc_top] = 0;
6986 rc = mdb_update_key(cdst, &nullkey);
6987 cdst->mc_ki[cdst->mc_top] = ix;
6988 assert(rc == MDB_SUCCESS);
6995 /** Merge one page into another.
6996 * The nodes from the page pointed to by \b csrc will
6997 * be copied to the page pointed to by \b cdst and then
6998 * the \b csrc page will be freed.
6999 * @param[in] csrc Cursor pointing to the source page.
7000 * @param[in] cdst Cursor pointing to the destination page.
7003 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
7011 DPRINTF(("merging page %"Z"u into %"Z"u", csrc->mc_pg[csrc->mc_top]->mp_pgno,
7012 cdst->mc_pg[cdst->mc_top]->mp_pgno));
7014 assert(csrc->mc_snum > 1); /* can't merge root page */
7015 assert(cdst->mc_snum > 1);
7017 /* Mark dst as dirty. */
7018 if ((rc = mdb_page_touch(cdst)))
7021 /* Move all nodes from src to dst.
7023 j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
7024 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7025 key.mv_size = csrc->mc_db->md_pad;
7026 key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
7027 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
7028 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
7029 if (rc != MDB_SUCCESS)
7031 key.mv_data = (char *)key.mv_data + key.mv_size;
7034 for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
7035 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
7036 if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
7037 unsigned int snum = csrc->mc_snum;
7039 /* must find the lowest key below src */
7040 mdb_page_search_lowest(csrc);
7041 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
7042 key.mv_size = csrc->mc_db->md_pad;
7043 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
7045 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
7046 key.mv_size = NODEKSZ(s2);
7047 key.mv_data = NODEKEY(s2);
7049 csrc->mc_snum = snum--;
7050 csrc->mc_top = snum;
7052 key.mv_size = srcnode->mn_ksize;
7053 key.mv_data = NODEKEY(srcnode);
7056 data.mv_size = NODEDSZ(srcnode);
7057 data.mv_data = NODEDATA(srcnode);
7058 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
7059 if (rc != MDB_SUCCESS)
7064 DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
7065 cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]),
7066 (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10));
7068 /* Unlink the src page from parent and add to free list.
7070 mdb_node_del(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0);
7071 if (csrc->mc_ki[csrc->mc_top-1] == 0) {
7074 rc = mdb_update_key(csrc, &key);
7080 rc = mdb_midl_append(&csrc->mc_txn->mt_free_pgs,
7081 csrc->mc_pg[csrc->mc_top]->mp_pgno);
7084 if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
7085 csrc->mc_db->md_leaf_pages--;
7087 csrc->mc_db->md_branch_pages--;
7089 /* Adjust other cursors pointing to mp */
7090 MDB_cursor *m2, *m3;
7091 MDB_dbi dbi = csrc->mc_dbi;
7092 MDB_page *mp = cdst->mc_pg[cdst->mc_top];
7094 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7095 if (csrc->mc_flags & C_SUB)
7096 m3 = &m2->mc_xcursor->mx_cursor;
7099 if (m3 == csrc) continue;
7100 if (m3->mc_snum < csrc->mc_snum) continue;
7101 if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) {
7102 m3->mc_pg[csrc->mc_top] = mp;
7103 m3->mc_ki[csrc->mc_top] += nkeys;
7107 mdb_cursor_pop(csrc);
7109 return mdb_rebalance(csrc);
7112 /** Copy the contents of a cursor.
7113 * @param[in] csrc The cursor to copy from.
7114 * @param[out] cdst The cursor to copy to.
7117 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
7121 cdst->mc_txn = csrc->mc_txn;
7122 cdst->mc_dbi = csrc->mc_dbi;
7123 cdst->mc_db = csrc->mc_db;
7124 cdst->mc_dbx = csrc->mc_dbx;
7125 cdst->mc_snum = csrc->mc_snum;
7126 cdst->mc_top = csrc->mc_top;
7127 cdst->mc_flags = csrc->mc_flags;
7129 for (i=0; i<csrc->mc_snum; i++) {
7130 cdst->mc_pg[i] = csrc->mc_pg[i];
7131 cdst->mc_ki[i] = csrc->mc_ki[i];
7135 /** Rebalance the tree after a delete operation.
7136 * @param[in] mc Cursor pointing to the page where rebalancing
7138 * @return 0 on success, non-zero on failure.
7141 mdb_rebalance(MDB_cursor *mc)
7145 unsigned int ptop, minkeys;
7148 minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
7152 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
7153 DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
7154 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
7155 pgno, NUMKEYS(mc->mc_pg[mc->mc_top]),
7156 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
7160 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD &&
7161 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
7164 COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno);
7165 DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
7171 if (mc->mc_snum < 2) {
7172 MDB_page *mp = mc->mc_pg[0];
7174 DPUTS("Can't rebalance a subpage, ignoring");
7177 if (NUMKEYS(mp) == 0) {
7178 DPUTS("tree is completely empty");
7179 mc->mc_db->md_root = P_INVALID;
7180 mc->mc_db->md_depth = 0;
7181 mc->mc_db->md_leaf_pages = 0;
7182 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7185 /* Adjust cursors pointing to mp */
7188 mc->mc_flags &= ~C_INITIALIZED;
7190 MDB_cursor *m2, *m3;
7191 MDB_dbi dbi = mc->mc_dbi;
7193 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7194 if (mc->mc_flags & C_SUB)
7195 m3 = &m2->mc_xcursor->mx_cursor;
7198 if (m3->mc_snum < mc->mc_snum) continue;
7199 if (m3->mc_pg[0] == mp) {
7202 m3->mc_flags &= ~C_INITIALIZED;
7206 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
7207 DPUTS("collapsing root page!");
7208 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
7211 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
7212 rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
7215 mc->mc_db->md_depth--;
7216 mc->mc_db->md_branch_pages--;
7217 mc->mc_ki[0] = mc->mc_ki[1];
7219 /* Adjust other cursors pointing to mp */
7220 MDB_cursor *m2, *m3;
7221 MDB_dbi dbi = mc->mc_dbi;
7223 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7224 if (mc->mc_flags & C_SUB)
7225 m3 = &m2->mc_xcursor->mx_cursor;
7228 if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
7229 if (m3->mc_pg[0] == mp) {
7233 for (i=0; i<m3->mc_snum; i++) {
7234 m3->mc_pg[i] = m3->mc_pg[i+1];
7235 m3->mc_ki[i] = m3->mc_ki[i+1];
7241 DPUTS("root page doesn't need rebalancing");
7245 /* The parent (branch page) must have at least 2 pointers,
7246 * otherwise the tree is invalid.
7248 ptop = mc->mc_top-1;
7249 assert(NUMKEYS(mc->mc_pg[ptop]) > 1);
7251 /* Leaf page fill factor is below the threshold.
7252 * Try to move keys from left or right neighbor, or
7253 * merge with a neighbor page.
7258 mdb_cursor_copy(mc, &mn);
7259 mn.mc_xcursor = NULL;
7261 if (mc->mc_ki[ptop] == 0) {
7262 /* We're the leftmost leaf in our parent.
7264 DPUTS("reading right neighbor");
7266 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7267 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7270 mn.mc_ki[mn.mc_top] = 0;
7271 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
7273 /* There is at least one neighbor to the left.
7275 DPUTS("reading left neighbor");
7277 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
7278 rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
7281 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
7282 mc->mc_ki[mc->mc_top] = 0;
7285 DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
7286 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
7287 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
7289 /* If the neighbor page is above threshold and has enough keys,
7290 * move one key from it. Otherwise we should try to merge them.
7291 * (A branch page must never have less than 2 keys.)
7293 minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
7294 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys)
7295 return mdb_node_move(&mn, mc);
7297 if (mc->mc_ki[ptop] == 0)
7298 rc = mdb_page_merge(&mn, mc);
7300 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
7301 rc = mdb_page_merge(mc, &mn);
7302 mdb_cursor_copy(&mn, mc);
7304 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
7309 /** Complete a delete operation started by #mdb_cursor_del(). */
7311 mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf)
7318 mp = mc->mc_pg[mc->mc_top];
7319 ki = mc->mc_ki[mc->mc_top];
7321 /* add overflow pages to free list */
7322 if (!IS_LEAF2(mp) && F_ISSET(leaf->mn_flags, F_BIGDATA)) {
7326 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
7327 if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
7328 (rc = mdb_ovpage_free(mc, omp)))
7331 mdb_node_del(mp, ki, mc->mc_db->md_pad);
7332 mc->mc_db->md_entries--;
7333 rc = mdb_rebalance(mc);
7334 if (rc != MDB_SUCCESS)
7335 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7338 MDB_dbi dbi = mc->mc_dbi;
7340 mp = mc->mc_pg[mc->mc_top];
7341 nkeys = NUMKEYS(mp);
7343 /* if mc points past last node in page, find next sibling */
7344 if (mc->mc_ki[mc->mc_top] >= nkeys)
7345 mdb_cursor_sibling(mc, 1);
7347 /* Adjust other cursors pointing to mp */
7348 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7349 if (m2 == mc || m2->mc_snum < mc->mc_snum)
7351 if (!(m2->mc_flags & C_INITIALIZED))
7353 if (m2->mc_pg[mc->mc_top] == mp) {
7354 if (m2->mc_ki[mc->mc_top] >= ki) {
7355 m2->mc_flags |= C_DEL;
7356 if (m2->mc_ki[mc->mc_top] > ki)
7357 m2->mc_ki[mc->mc_top]--;
7359 if (m2->mc_ki[mc->mc_top] >= nkeys)
7360 mdb_cursor_sibling(m2, 1);
7363 mc->mc_flags |= C_DEL;
7370 mdb_del(MDB_txn *txn, MDB_dbi dbi,
7371 MDB_val *key, MDB_val *data)
7376 MDB_val rdata, *xdata;
7380 assert(key != NULL);
7382 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
7384 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
7387 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
7388 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
7390 if (key->mv_size > MDB_MAXKEYSIZE) {
7391 return MDB_BAD_VALSIZE;
7394 mdb_cursor_init(&mc, txn, dbi, &mx);
7397 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
7398 /* must ignore any data */
7409 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
7411 /* let mdb_page_split know about this cursor if needed:
7412 * delete will trigger a rebalance; if it needs to move
7413 * a node from one page to another, it will have to
7414 * update the parent's separator key(s). If the new sepkey
7415 * is larger than the current one, the parent page may
7416 * run out of space, triggering a split. We need this
7417 * cursor to be consistent until the end of the rebalance.
7419 mc.mc_flags |= C_UNTRACK;
7420 mc.mc_next = txn->mt_cursors[dbi];
7421 txn->mt_cursors[dbi] = &mc;
7422 rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA);
7423 txn->mt_cursors[dbi] = mc.mc_next;
7428 /** Split a page and insert a new node.
7429 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
7430 * The cursor will be updated to point to the actual page and index where
7431 * the node got inserted after the split.
7432 * @param[in] newkey The key for the newly inserted node.
7433 * @param[in] newdata The data for the newly inserted node.
7434 * @param[in] newpgno The page number, if the new node is a branch node.
7435 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
7436 * @return 0 on success, non-zero on failure.
7439 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
7440 unsigned int nflags)
7443 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
7446 int i, j, split_indx, nkeys, pmax;
7447 MDB_env *env = mc->mc_txn->mt_env;
7449 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
7450 MDB_page *copy = NULL;
7451 MDB_page *mp, *rp, *pp;
7456 mp = mc->mc_pg[mc->mc_top];
7457 newindx = mc->mc_ki[mc->mc_top];
7458 nkeys = NUMKEYS(mp);
7460 DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
7461 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
7462 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
7464 /* Create a right sibling. */
7465 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
7467 DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
7469 if (mc->mc_snum < 2) {
7470 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
7472 /* shift current top to make room for new parent */
7473 mc->mc_pg[1] = mc->mc_pg[0];
7474 mc->mc_ki[1] = mc->mc_ki[0];
7477 mc->mc_db->md_root = pp->mp_pgno;
7478 DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
7479 mc->mc_db->md_depth++;
7482 /* Add left (implicit) pointer. */
7483 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
7484 /* undo the pre-push */
7485 mc->mc_pg[0] = mc->mc_pg[1];
7486 mc->mc_ki[0] = mc->mc_ki[1];
7487 mc->mc_db->md_root = mp->mp_pgno;
7488 mc->mc_db->md_depth--;
7495 ptop = mc->mc_top-1;
7496 DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
7499 mc->mc_flags |= C_SPLITTING;
7500 mdb_cursor_copy(mc, &mn);
7501 mn.mc_pg[mn.mc_top] = rp;
7502 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
7504 if (nflags & MDB_APPEND) {
7505 mn.mc_ki[mn.mc_top] = 0;
7507 split_indx = newindx;
7511 split_indx = (nkeys+1) / 2;
7516 unsigned int lsize, rsize, ksize;
7517 /* Move half of the keys to the right sibling */
7519 x = mc->mc_ki[mc->mc_top] - split_indx;
7520 ksize = mc->mc_db->md_pad;
7521 split = LEAF2KEY(mp, split_indx, ksize);
7522 rsize = (nkeys - split_indx) * ksize;
7523 lsize = (nkeys - split_indx) * sizeof(indx_t);
7524 mp->mp_lower -= lsize;
7525 rp->mp_lower += lsize;
7526 mp->mp_upper += rsize - lsize;
7527 rp->mp_upper -= rsize - lsize;
7528 sepkey.mv_size = ksize;
7529 if (newindx == split_indx) {
7530 sepkey.mv_data = newkey->mv_data;
7532 sepkey.mv_data = split;
7535 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
7536 memcpy(rp->mp_ptrs, split, rsize);
7537 sepkey.mv_data = rp->mp_ptrs;
7538 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
7539 memcpy(ins, newkey->mv_data, ksize);
7540 mp->mp_lower += sizeof(indx_t);
7541 mp->mp_upper -= ksize - sizeof(indx_t);
7544 memcpy(rp->mp_ptrs, split, x * ksize);
7545 ins = LEAF2KEY(rp, x, ksize);
7546 memcpy(ins, newkey->mv_data, ksize);
7547 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
7548 rp->mp_lower += sizeof(indx_t);
7549 rp->mp_upper -= ksize - sizeof(indx_t);
7550 mc->mc_ki[mc->mc_top] = x;
7551 mc->mc_pg[mc->mc_top] = rp;
7554 int psize, nsize, k;
7555 /* Maximum free space in an empty page */
7556 pmax = env->me_psize - PAGEHDRSZ;
7558 nsize = mdb_leaf_size(env, newkey, newdata);
7560 nsize = mdb_branch_size(env, newkey);
7563 /* grab a page to hold a temporary copy */
7564 copy = mdb_page_malloc(mc->mc_txn, 1);
7567 copy->mp_pgno = mp->mp_pgno;
7568 copy->mp_flags = mp->mp_flags;
7569 copy->mp_lower = PAGEHDRSZ;
7570 copy->mp_upper = env->me_psize;
7572 /* prepare to insert */
7573 for (i=0, j=0; i<nkeys; i++) {
7575 copy->mp_ptrs[j++] = 0;
7577 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
7580 /* When items are relatively large the split point needs
7581 * to be checked, because being off-by-one will make the
7582 * difference between success or failure in mdb_node_add.
7584 * It's also relevant if a page happens to be laid out
7585 * such that one half of its nodes are all "small" and
7586 * the other half of its nodes are "large." If the new
7587 * item is also "large" and falls on the half with
7588 * "large" nodes, it also may not fit.
7590 * As a final tweak, if the new item goes on the last
7591 * spot on the page (and thus, onto the new page), bias
7592 * the split so the new page is emptier than the old page.
7593 * This yields better packing during sequential inserts.
7595 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
7596 /* Find split point */
7598 if (newindx <= split_indx || newindx >= nkeys) {
7600 k = newindx >= nkeys ? nkeys : split_indx+2;
7605 for (; i!=k; i+=j) {
7610 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i]);
7611 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
7613 if (F_ISSET(node->mn_flags, F_BIGDATA))
7614 psize += sizeof(pgno_t);
7616 psize += NODEDSZ(node);
7620 if (psize > pmax || i == k-j) {
7621 split_indx = i + (j<0);
7626 if (split_indx == newindx) {
7627 sepkey.mv_size = newkey->mv_size;
7628 sepkey.mv_data = newkey->mv_data;
7630 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx]);
7631 sepkey.mv_size = node->mn_ksize;
7632 sepkey.mv_data = NODEKEY(node);
7637 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
7639 /* Copy separator key to the parent.
7641 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
7645 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
7648 if (mn.mc_snum == mc->mc_snum) {
7649 mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
7650 mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
7651 mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
7652 mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
7657 /* Right page might now have changed parent.
7658 * Check if left page also changed parent.
7660 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
7661 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
7662 for (i=0; i<ptop; i++) {
7663 mc->mc_pg[i] = mn.mc_pg[i];
7664 mc->mc_ki[i] = mn.mc_ki[i];
7666 mc->mc_pg[ptop] = mn.mc_pg[ptop];
7667 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
7671 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
7674 mc->mc_flags ^= C_SPLITTING;
7675 if (rc != MDB_SUCCESS) {
7678 if (nflags & MDB_APPEND) {
7679 mc->mc_pg[mc->mc_top] = rp;
7680 mc->mc_ki[mc->mc_top] = 0;
7681 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
7684 for (i=0; i<mc->mc_top; i++)
7685 mc->mc_ki[i] = mn.mc_ki[i];
7686 } else if (!IS_LEAF2(mp)) {
7688 mc->mc_pg[mc->mc_top] = rp;
7693 rkey.mv_data = newkey->mv_data;
7694 rkey.mv_size = newkey->mv_size;
7700 /* Update index for the new key. */
7701 mc->mc_ki[mc->mc_top] = j;
7703 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i]);
7704 rkey.mv_data = NODEKEY(node);
7705 rkey.mv_size = node->mn_ksize;
7707 xdata.mv_data = NODEDATA(node);
7708 xdata.mv_size = NODEDSZ(node);
7711 pgno = NODEPGNO(node);
7712 flags = node->mn_flags;
7715 if (!IS_LEAF(mp) && j == 0) {
7716 /* First branch index doesn't need key data. */
7720 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
7722 /* return tmp page to freelist */
7723 mdb_page_free(env, copy);
7729 mc->mc_pg[mc->mc_top] = copy;
7734 } while (i != split_indx);
7736 nkeys = NUMKEYS(copy);
7737 for (i=0; i<nkeys; i++)
7738 mp->mp_ptrs[i] = copy->mp_ptrs[i];
7739 mp->mp_lower = copy->mp_lower;
7740 mp->mp_upper = copy->mp_upper;
7741 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
7742 env->me_psize - copy->mp_upper);
7744 /* reset back to original page */
7745 if (newindx < split_indx) {
7746 mc->mc_pg[mc->mc_top] = mp;
7747 if (nflags & MDB_RESERVE) {
7748 node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
7749 if (!(node->mn_flags & F_BIGDATA))
7750 newdata->mv_data = NODEDATA(node);
7753 mc->mc_pg[mc->mc_top] = rp;
7755 /* Make sure mc_ki is still valid.
7757 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
7758 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
7759 for (i=0; i<ptop; i++) {
7760 mc->mc_pg[i] = mn.mc_pg[i];
7761 mc->mc_ki[i] = mn.mc_ki[i];
7763 mc->mc_pg[ptop] = mn.mc_pg[ptop];
7764 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
7767 /* return tmp page to freelist */
7768 mdb_page_free(env, copy);
7772 /* Adjust other cursors pointing to mp */
7773 MDB_cursor *m2, *m3;
7774 MDB_dbi dbi = mc->mc_dbi;
7775 int fixup = NUMKEYS(mp);
7777 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7778 if (mc->mc_flags & C_SUB)
7779 m3 = &m2->mc_xcursor->mx_cursor;
7784 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
7786 if (m3->mc_flags & C_SPLITTING)
7791 for (k=m3->mc_top; k>=0; k--) {
7792 m3->mc_ki[k+1] = m3->mc_ki[k];
7793 m3->mc_pg[k+1] = m3->mc_pg[k];
7795 if (m3->mc_ki[0] >= split_indx) {
7800 m3->mc_pg[0] = mc->mc_pg[0];
7804 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
7805 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
7806 m3->mc_ki[mc->mc_top]++;
7807 if (m3->mc_ki[mc->mc_top] >= fixup) {
7808 m3->mc_pg[mc->mc_top] = rp;
7809 m3->mc_ki[mc->mc_top] -= fixup;
7810 m3->mc_ki[ptop] = mn.mc_ki[ptop];
7812 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
7813 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
7818 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
7823 mdb_put(MDB_txn *txn, MDB_dbi dbi,
7824 MDB_val *key, MDB_val *data, unsigned int flags)
7829 assert(key != NULL);
7830 assert(data != NULL);
7832 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
7835 if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags)
7838 mdb_cursor_init(&mc, txn, dbi, &mx);
7839 return mdb_cursor_put(&mc, key, data, flags);
7843 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
7845 if ((flag & CHANGEABLE) != flag)
7848 env->me_flags |= flag;
7850 env->me_flags &= ~flag;
7855 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
7860 *arg = env->me_flags;
7865 mdb_env_get_path(MDB_env *env, const char **arg)
7870 *arg = env->me_path;
7875 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
7884 /** Common code for #mdb_stat() and #mdb_env_stat().
7885 * @param[in] env the environment to operate in.
7886 * @param[in] db the #MDB_db record containing the stats to return.
7887 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
7888 * @return 0, this function always succeeds.
7891 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
7893 arg->ms_psize = env->me_psize;
7894 arg->ms_depth = db->md_depth;
7895 arg->ms_branch_pages = db->md_branch_pages;
7896 arg->ms_leaf_pages = db->md_leaf_pages;
7897 arg->ms_overflow_pages = db->md_overflow_pages;
7898 arg->ms_entries = db->md_entries;
7903 mdb_env_stat(MDB_env *env, MDB_stat *arg)
7907 if (env == NULL || arg == NULL)
7910 toggle = mdb_env_pick_meta(env);
7912 return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
7916 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
7920 if (env == NULL || arg == NULL)
7923 toggle = mdb_env_pick_meta(env);
7924 arg->me_mapaddr = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : 0;
7925 arg->me_mapsize = env->me_mapsize;
7926 arg->me_maxreaders = env->me_maxreaders;
7928 /* me_numreaders may be zero if this process never used any readers. Use
7929 * the shared numreader count if it exists.
7931 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
7933 arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
7934 arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
7938 /** Set the default comparison functions for a database.
7939 * Called immediately after a database is opened to set the defaults.
7940 * The user can then override them with #mdb_set_compare() or
7941 * #mdb_set_dupsort().
7942 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
7943 * @param[in] dbi A database handle returned by #mdb_dbi_open()
7946 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
7948 uint16_t f = txn->mt_dbs[dbi].md_flags;
7950 txn->mt_dbxs[dbi].md_cmp =
7951 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
7952 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
7954 txn->mt_dbxs[dbi].md_dcmp =
7955 !(f & MDB_DUPSORT) ? 0 :
7956 ((f & MDB_INTEGERDUP)
7957 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
7958 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
7961 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
7966 int rc, dbflag, exact;
7967 unsigned int unused = 0;
7970 if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
7971 mdb_default_cmp(txn, FREE_DBI);
7974 if ((flags & VALID_FLAGS) != flags)
7976 if (txn->mt_flags & MDB_TXN_ERROR)
7982 if (flags & PERSISTENT_FLAGS) {
7983 uint16_t f2 = flags & PERSISTENT_FLAGS;
7984 /* make sure flag changes get committed */
7985 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
7986 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
7987 txn->mt_flags |= MDB_TXN_DIRTY;
7990 mdb_default_cmp(txn, MAIN_DBI);
7994 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
7995 mdb_default_cmp(txn, MAIN_DBI);
7998 /* Is the DB already open? */
8000 for (i=2; i<txn->mt_numdbs; i++) {
8001 if (!txn->mt_dbxs[i].md_name.mv_size) {
8002 /* Remember this free slot */
8003 if (!unused) unused = i;
8006 if (len == txn->mt_dbxs[i].md_name.mv_size &&
8007 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
8013 /* If no free slot and max hit, fail */
8014 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
8015 return MDB_DBS_FULL;
8017 /* Cannot mix named databases with some mainDB flags */
8018 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
8019 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
8021 /* Find the DB info */
8022 dbflag = DB_NEW|DB_VALID;
8025 key.mv_data = (void *)name;
8026 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
8027 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
8028 if (rc == MDB_SUCCESS) {
8029 /* make sure this is actually a DB */
8030 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
8031 if (!(node->mn_flags & F_SUBDATA))
8032 return MDB_INCOMPATIBLE;
8033 } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
8034 /* Create if requested */
8036 data.mv_size = sizeof(MDB_db);
8037 data.mv_data = &dummy;
8038 memset(&dummy, 0, sizeof(dummy));
8039 dummy.md_root = P_INVALID;
8040 dummy.md_flags = flags & PERSISTENT_FLAGS;
8041 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
8045 /* OK, got info, add to table */
8046 if (rc == MDB_SUCCESS) {
8047 unsigned int slot = unused ? unused : txn->mt_numdbs;
8048 txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
8049 txn->mt_dbxs[slot].md_name.mv_size = len;
8050 txn->mt_dbxs[slot].md_rel = NULL;
8051 txn->mt_dbflags[slot] = dbflag;
8052 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
8054 mdb_default_cmp(txn, slot);
8063 int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
8065 if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs)
8068 if (txn->mt_dbflags[dbi] & DB_STALE) {
8071 /* Stale, must read the DB's root. cursor_init does it for us. */
8072 mdb_cursor_init(&mc, txn, dbi, &mx);
8074 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
8077 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
8080 if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs)
8082 ptr = env->me_dbxs[dbi].md_name.mv_data;
8083 env->me_dbxs[dbi].md_name.mv_data = NULL;
8084 env->me_dbxs[dbi].md_name.mv_size = 0;
8085 env->me_dbflags[dbi] = 0;
8089 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
8091 /* We could return the flags for the FREE_DBI too but what's the point? */
8092 if (txn == NULL || dbi < MAIN_DBI || dbi >= txn->mt_numdbs)
8094 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
8098 /** Add all the DB's pages to the free list.
8099 * @param[in] mc Cursor on the DB to free.
8100 * @param[in] subs non-Zero to check for sub-DBs in this DB.
8101 * @return 0 on success, non-zero on failure.
8104 mdb_drop0(MDB_cursor *mc, int subs)
8108 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
8109 if (rc == MDB_SUCCESS) {
8110 MDB_txn *txn = mc->mc_txn;
8115 /* LEAF2 pages have no nodes, cannot have sub-DBs */
8116 if (IS_LEAF2(mc->mc_pg[mc->mc_top]))
8119 mdb_cursor_copy(mc, &mx);
8120 while (mc->mc_snum > 0) {
8121 MDB_page *mp = mc->mc_pg[mc->mc_top];
8122 unsigned n = NUMKEYS(mp);
8124 for (i=0; i<n; i++) {
8125 ni = NODEPTR(mp, i);
8126 if (ni->mn_flags & F_BIGDATA) {
8129 memcpy(&pg, NODEDATA(ni), sizeof(pg));
8130 rc = mdb_page_get(txn, pg, &omp, NULL);
8133 assert(IS_OVERFLOW(omp));
8134 rc = mdb_midl_append_range(&txn->mt_free_pgs,
8138 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
8139 mdb_xcursor_init1(mc, ni);
8140 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
8146 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
8148 for (i=0; i<n; i++) {
8150 ni = NODEPTR(mp, i);
8153 mdb_midl_xappend(txn->mt_free_pgs, pg);
8158 mc->mc_ki[mc->mc_top] = i;
8159 rc = mdb_cursor_sibling(mc, 1);
8161 /* no more siblings, go back to beginning
8162 * of previous level.
8166 for (i=1; i<mc->mc_snum; i++) {
8168 mc->mc_pg[i] = mx.mc_pg[i];
8173 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
8174 } else if (rc == MDB_NOTFOUND) {
8180 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
8182 MDB_cursor *mc, *m2;
8185 if (!txn || !dbi || dbi >= txn->mt_numdbs || (unsigned)del > 1 || !(txn->mt_dbflags[dbi] & DB_VALID))
8188 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
8191 rc = mdb_cursor_open(txn, dbi, &mc);
8195 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
8196 /* Invalidate the dropped DB's cursors */
8197 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
8198 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
8202 /* Can't delete the main DB */
8203 if (del && dbi > MAIN_DBI) {
8204 rc = mdb_del(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL);
8206 txn->mt_dbflags[dbi] = DB_STALE;
8207 mdb_dbi_close(txn->mt_env, dbi);
8210 /* reset the DB record, mark it dirty */
8211 txn->mt_dbflags[dbi] |= DB_DIRTY;
8212 txn->mt_dbs[dbi].md_depth = 0;
8213 txn->mt_dbs[dbi].md_branch_pages = 0;
8214 txn->mt_dbs[dbi].md_leaf_pages = 0;
8215 txn->mt_dbs[dbi].md_overflow_pages = 0;
8216 txn->mt_dbs[dbi].md_entries = 0;
8217 txn->mt_dbs[dbi].md_root = P_INVALID;
8219 txn->mt_flags |= MDB_TXN_DIRTY;
8222 mdb_cursor_close(mc);
8226 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
8228 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8231 txn->mt_dbxs[dbi].md_cmp = cmp;
8235 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
8237 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8240 txn->mt_dbxs[dbi].md_dcmp = cmp;
8244 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
8246 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8249 txn->mt_dbxs[dbi].md_rel = rel;
8253 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
8255 if (txn == NULL || !dbi || dbi >= txn->mt_numdbs || !(txn->mt_dbflags[dbi] & DB_VALID))
8258 txn->mt_dbxs[dbi].md_relctx = ctx;
8262 int mdb_env_get_maxkeysize(MDB_env *env)
8264 return MDB_MAXKEYSIZE;
8267 int mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
8269 unsigned int i, rdrs;
8276 if (!env->me_txns) {
8277 return func("(no reader locks)\n", ctx);
8279 rdrs = env->me_txns->mti_numreaders;
8280 mr = env->me_txns->mti_readers;
8281 for (i=0; i<rdrs; i++) {
8286 if (mr[i].mr_txnid == (txnid_t)-1) {
8287 sprintf(buf, "%10d %"Z"x -\n", mr[i].mr_pid, tid);
8289 sprintf(buf, "%10d %"Z"x %"Z"u\n", mr[i].mr_pid, tid, mr[i].mr_txnid);
8293 func(" pid thread txnid\n", ctx);
8295 rc = func(buf, ctx);
8301 func("(no active readers)\n", ctx);
8306 /** Insert pid into list if not already present.
8307 * return -1 if already present.
8309 static int mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
8311 /* binary search of pid in list */
8313 unsigned cursor = 1;
8315 unsigned n = ids[0];
8318 unsigned pivot = n >> 1;
8319 cursor = base + pivot + 1;
8320 val = pid - ids[cursor];
8325 } else if ( val > 0 ) {
8330 /* found, so it's a duplicate */
8339 for (n = ids[0]; n > cursor; n--)
8345 int mdb_reader_check(MDB_env *env, int *dead)
8347 unsigned int i, j, rdrs;
8349 MDB_PID_T *pids, pid;
8358 rdrs = env->me_txns->mti_numreaders;
8359 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
8363 mr = env->me_txns->mti_readers;
8365 for (i=0; i<rdrs; i++) {
8366 if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
8368 if (mdb_pid_insert(pids, pid) == 0) {
8369 if (!mdb_reader_pid(env, Pidcheck, pid)) {
8371 /* Recheck, a new process may have reused pid */
8372 if (!mdb_reader_pid(env, Pidcheck, pid)) {
8373 for (j=i; j<rdrs; j++)
8374 if (mr[j].mr_pid == pid) {
8375 DPRINTF(("clear stale reader pid %u txn %"Z"d",
8376 (unsigned) pid, mr[j].mr_txnid));
8381 UNLOCK_MUTEX_R(env);
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