/** @file mdb.c * @brief memory-mapped database library * * A Btree-based database management library modeled loosely on the * BerkeleyDB API, but much simplified. */ /* * Copyright 2011-2012 Howard Chu, Symas Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted only as authorized by the OpenLDAP * Public License. * * A copy of this license is available in the file LICENSE in the * top-level directory of the distribution or, alternatively, at * . * * This code is derived from btree.c written by Martin Hedenfalk. * * Copyright (c) 2009, 2010 Martin Hedenfalk * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #ifdef _WIN32 #include #else #include #include #ifdef HAVE_SYS_FILE_H #include #endif #include #endif #include #include #include #include #include #include #include #include #include #include #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER)) #include /* defines BYTE_ORDER on HPUX and Solaris */ #endif #if defined(__APPLE__) || defined (BSD) #define USE_POSIX_SEM #endif #ifndef _WIN32 #include #ifdef USE_POSIX_SEM #include #endif #endif #ifdef USE_VALGRIND #include #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z) #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s) #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a) #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h) #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s) #else #define VGMEMP_CREATE(h,r,z) #define VGMEMP_ALLOC(h,a,s) #define VGMEMP_FREE(h,a) #define VGMEMP_DESTROY(h) #define VGMEMP_DEFINED(a,s) #endif #ifndef BYTE_ORDER # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)) /* Solaris just defines one or the other */ # define LITTLE_ENDIAN 1234 # define BIG_ENDIAN 4321 # ifdef _LITTLE_ENDIAN # define BYTE_ORDER LITTLE_ENDIAN # else # define BYTE_ORDER BIG_ENDIAN # endif # else # define BYTE_ORDER __BYTE_ORDER # endif #endif #ifndef LITTLE_ENDIAN #define LITTLE_ENDIAN __LITTLE_ENDIAN #endif #ifndef BIG_ENDIAN #define BIG_ENDIAN __BIG_ENDIAN #endif #if defined(__i386) || defined(__x86_64) #define MISALIGNED_OK 1 #endif #include "mdb.h" #include "midl.h" #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN) # error "Unknown or unsupported endianness (BYTE_ORDER)" #elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF # error "Two's complement, reasonably sized integer types, please" #endif /** @defgroup internal MDB Internals * @{ */ /** @defgroup compat Windows Compatibility Macros * A bunch of macros to minimize the amount of platform-specific ifdefs * needed throughout the rest of the code. When the features this library * needs are similar enough to POSIX to be hidden in a one-or-two line * replacement, this macro approach is used. * @{ */ #ifdef _WIN32 #define pthread_t DWORD #define pthread_mutex_t HANDLE #define pthread_key_t DWORD #define pthread_self() GetCurrentThreadId() #define pthread_key_create(x,y) (*(x) = TlsAlloc()) #define pthread_key_delete(x) TlsFree(x) #define pthread_getspecific(x) TlsGetValue(x) #define pthread_setspecific(x,y) TlsSetValue(x,y) #define pthread_mutex_unlock(x) ReleaseMutex(x) #define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE) #define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex) #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex) #define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex) #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex) #define getpid() GetCurrentProcessId() #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd)) #define ErrCode() GetLastError() #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;} #define close(fd) CloseHandle(fd) #define munmap(ptr,len) UnmapViewOfFile(ptr) #else #ifdef USE_POSIX_SEM #define LOCK_MUTEX_R(env) sem_wait((env)->me_rmutex) #define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex) #define LOCK_MUTEX_W(env) sem_wait((env)->me_wmutex) #define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex) #define MDB_FDATASYNC(fd) fsync(fd) #else #ifdef ANDROID #define MDB_FDATASYNC(fd) fsync(fd) #endif /** Lock the reader mutex. */ #define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex) /** Unlock the reader mutex. */ #define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex) /** Lock the writer mutex. * Only a single write transaction is allowed at a time. Other writers * will block waiting for this mutex. */ #define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex) /** Unlock the writer mutex. */ #define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex) #endif /* USE_POSIX_SEM */ /** Get the error code for the last failed system function. */ #define ErrCode() errno /** An abstraction for a file handle. * On POSIX systems file handles are small integers. On Windows * they're opaque pointers. */ #define HANDLE int /** A value for an invalid file handle. * Mainly used to initialize file variables and signify that they are * unused. */ #define INVALID_HANDLE_VALUE (-1) /** Get the size of a memory page for the system. * This is the basic size that the platform's memory manager uses, and is * fundamental to the use of memory-mapped files. */ #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE)) #endif #if defined(_WIN32) || defined(USE_POSIX_SEM) #define MNAME_LEN 32 #else #define MNAME_LEN (sizeof(pthread_mutex_t)) #endif /** @} */ #ifndef _WIN32 /** A flag for opening a file and requesting synchronous data writes. * This is only used when writing a meta page. It's not strictly needed; * we could just do a normal write and then immediately perform a flush. * But if this flag is available it saves us an extra system call. * * @note If O_DSYNC is undefined but exists in /usr/include, * preferably set some compiler flag to get the definition. * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC. */ #ifndef MDB_DSYNC # define MDB_DSYNC O_DSYNC #endif #endif /** Function for flushing the data of a file. Define this to fsync * if fdatasync() is not supported. */ #ifndef MDB_FDATASYNC # define MDB_FDATASYNC fdatasync #endif /** A page number in the database. * Note that 64 bit page numbers are overkill, since pages themselves * already represent 12-13 bits of addressable memory, and the OS will * always limit applications to a maximum of 63 bits of address space. * * @note In the #MDB_node structure, we only store 48 bits of this value, * which thus limits us to only 60 bits of addressable data. */ typedef MDB_ID pgno_t; /** A transaction ID. * See struct MDB_txn.mt_txnid for details. */ typedef MDB_ID txnid_t; /** @defgroup debug Debug Macros * @{ */ #ifndef MDB_DEBUG /** Enable debug output. * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs * read from and written to the database (used for free space management). */ #define MDB_DEBUG 0 #endif #if !(__STDC_VERSION__ >= 199901L || defined(__GNUC__)) # define DPRINTF (void) /* Vararg macros may be unsupported */ #elif MDB_DEBUG static int mdb_debug; static txnid_t mdb_debug_start; /** Print a debug message with printf formatting. */ # define DPRINTF(fmt, ...) /**< Requires 2 or more args */ \ ((void) ((mdb_debug) && \ fprintf(stderr, "%s:%d " fmt "\n", __func__, __LINE__, __VA_ARGS__))) #else # define DPRINTF(fmt, ...) ((void) 0) #endif /** Print a debug string. * The string is printed literally, with no format processing. */ #define DPUTS(arg) DPRINTF("%s", arg) /** @} */ /** A default memory page size. * The actual size is platform-dependent, but we use this for * boot-strapping. We probably should not be using this any more. * The #GET_PAGESIZE() macro is used to get the actual size. * * Note that we don't currently support Huge pages. On Linux, * regular data files cannot use Huge pages, and in general * Huge pages aren't actually pageable. We rely on the OS * demand-pager to read our data and page it out when memory * pressure from other processes is high. So until OSs have * actual paging support for Huge pages, they're not viable. */ #define MDB_PAGESIZE 4096 /** The minimum number of keys required in a database page. * Setting this to a larger value will place a smaller bound on the * maximum size of a data item. Data items larger than this size will * be pushed into overflow pages instead of being stored directly in * the B-tree node. This value used to default to 4. With a page size * of 4096 bytes that meant that any item larger than 1024 bytes would * go into an overflow page. That also meant that on average 2-3KB of * each overflow page was wasted space. The value cannot be lower than * 2 because then there would no longer be a tree structure. With this * value, items larger than 2KB will go into overflow pages, and on * average only 1KB will be wasted. */ #define MDB_MINKEYS 2 /** A stamp that identifies a file as an MDB file. * There's nothing special about this value other than that it is easily * recognizable, and it will reflect any byte order mismatches. */ #define MDB_MAGIC 0xBEEFC0DE /** The version number for a database's file format. */ #define MDB_VERSION 1 /** The maximum size of a key in the database. * While data items have essentially unbounded size, we require that * keys all fit onto a regular page. This limit could be raised a bit * further if needed; to something just under #MDB_PAGESIZE / #MDB_MINKEYS. */ #define MAXKEYSIZE 511 #if MDB_DEBUG /** A key buffer. * @ingroup debug * This is used for printing a hex dump of a key's contents. */ #define DKBUF char kbuf[(MAXKEYSIZE*2+1)] /** Display a key in hex. * @ingroup debug * Invoke a function to display a key in hex. */ #define DKEY(x) mdb_dkey(x, kbuf) #else #define DKBUF typedef int dummy_kbuf /* so we can put ';' after */ #define DKEY(x) 0 #endif /** An invalid page number. * Mainly used to denote an empty tree. */ #define P_INVALID (~0UL) /** Test if a flag \b f is set in a flag word \b w. */ #define F_ISSET(w, f) (((w) & (f)) == (f)) /** Used for offsets within a single page. * Since memory pages are typically 4 or 8KB in size, 12-13 bits, * this is plenty. */ typedef uint16_t indx_t; /** Default size of memory map. * This is certainly too small for any actual applications. Apps should always set * the size explicitly using #mdb_env_set_mapsize(). */ #define DEFAULT_MAPSIZE 1048576 /** @defgroup readers Reader Lock Table * Readers don't acquire any locks for their data access. Instead, they * simply record their transaction ID in the reader table. The reader * mutex is needed just to find an empty slot in the reader table. The * slot's address is saved in thread-specific data so that subsequent read * transactions started by the same thread need no further locking to proceed. * * Since the database uses multi-version concurrency control, readers don't * actually need any locking. This table is used to keep track of which * readers are using data from which old transactions, so that we'll know * when a particular old transaction is no longer in use. Old transactions * that have discarded any data pages can then have those pages reclaimed * for use by a later write transaction. * * The lock table is constructed such that reader slots are aligned with the * processor's cache line size. Any slot is only ever used by one thread. * This alignment guarantees that there will be no contention or cache * thrashing as threads update their own slot info, and also eliminates * any need for locking when accessing a slot. * * A writer thread will scan every slot in the table to determine the oldest * outstanding reader transaction. Any freed pages older than this will be * reclaimed by the writer. The writer doesn't use any locks when scanning * this table. This means that there's no guarantee that the writer will * see the most up-to-date reader info, but that's not required for correct * operation - all we need is to know the upper bound on the oldest reader, * we don't care at all about the newest reader. So the only consequence of * reading stale information here is that old pages might hang around a * while longer before being reclaimed. That's actually good anyway, because * the longer we delay reclaiming old pages, the more likely it is that a * string of contiguous pages can be found after coalescing old pages from * many old transactions together. * * @todo We don't actually do such coalescing yet, we grab pages from one * old transaction at a time. * @{ */ /** Number of slots in the reader table. * This value was chosen somewhat arbitrarily. 126 readers plus a * couple mutexes fit exactly into 8KB on my development machine. * Applications should set the table size using #mdb_env_set_maxreaders(). */ #define DEFAULT_READERS 126 /** The size of a CPU cache line in bytes. We want our lock structures * aligned to this size to avoid false cache line sharing in the * lock table. * This value works for most CPUs. For Itanium this should be 128. */ #ifndef CACHELINE #define CACHELINE 64 #endif /** The information we store in a single slot of the reader table. * In addition to a transaction ID, we also record the process and * thread ID that owns a slot, so that we can detect stale information, * e.g. threads or processes that went away without cleaning up. * @note We currently don't check for stale records. We simply re-init * the table when we know that we're the only process opening the * lock file. */ typedef struct MDB_rxbody { /** The current Transaction ID when this transaction began. * Multiple readers that start at the same time will probably have the * same ID here. Again, it's not important to exclude them from * anything; all we need to know is which version of the DB they * started from so we can avoid overwriting any data used in that * particular version. */ txnid_t mrb_txnid; /** The process ID of the process owning this reader txn. */ pid_t mrb_pid; /** The thread ID of the thread owning this txn. */ pthread_t mrb_tid; } MDB_rxbody; /** The actual reader record, with cacheline padding. */ typedef struct MDB_reader { union { MDB_rxbody mrx; /** shorthand for mrb_txnid */ #define mr_txnid mru.mrx.mrb_txnid #define mr_pid mru.mrx.mrb_pid #define mr_tid mru.mrx.mrb_tid /** cache line alignment */ char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)]; } mru; } MDB_reader; /** The header for the reader table. * The table resides in a memory-mapped file. (This is a different file * than is used for the main database.) * * For POSIX the actual mutexes reside in the shared memory of this * mapped file. On Windows, mutexes are named objects allocated by the * kernel; we store the mutex names in this mapped file so that other * processes can grab them. This same approach is also used on * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support * process-shared POSIX mutexes. For these cases where a named object * is used, the object name is derived from a 64 bit FNV hash of the * environment pathname. As such, naming collisions are extremely * unlikely. If a collision occurs, the results are unpredictable. */ typedef struct MDB_txbody { /** Stamp identifying this as an MDB file. It must be set * to #MDB_MAGIC. */ uint32_t mtb_magic; /** Version number of this lock file. Must be set to #MDB_VERSION. */ uint32_t mtb_version; #if defined(_WIN32) || defined(USE_POSIX_SEM) char mtb_rmname[MNAME_LEN]; #else /** Mutex protecting access to this table. * This is the reader lock that #LOCK_MUTEX_R acquires. */ pthread_mutex_t mtb_mutex; #endif /** The ID of the last transaction committed to the database. * This is recorded here only for convenience; the value can always * be determined by reading the main database meta pages. */ txnid_t mtb_txnid; /** The number of slots that have been used in the reader table. * This always records the maximum count, it is not decremented * when readers release their slots. */ unsigned mtb_numreaders; } MDB_txbody; /** The actual reader table definition. */ typedef struct MDB_txninfo { union { MDB_txbody mtb; #define mti_magic mt1.mtb.mtb_magic #define mti_version mt1.mtb.mtb_version #define mti_mutex mt1.mtb.mtb_mutex #define mti_rmname mt1.mtb.mtb_rmname #define mti_txnid mt1.mtb.mtb_txnid #define mti_numreaders mt1.mtb.mtb_numreaders char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)]; } mt1; union { #if defined(_WIN32) || defined(USE_POSIX_SEM) char mt2_wmname[MNAME_LEN]; #define mti_wmname mt2.mt2_wmname #else pthread_mutex_t mt2_wmutex; #define mti_wmutex mt2.mt2_wmutex #endif char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)]; } mt2; MDB_reader mti_readers[1]; } MDB_txninfo; /** @} */ /** Common header for all page types. * Overflow records occupy a number of contiguous pages with no * headers on any page after the first. */ typedef struct MDB_page { #define mp_pgno mp_p.p_pgno #define mp_next mp_p.p_next union { pgno_t p_pgno; /**< page number */ void * p_next; /**< for in-memory list of freed structs */ } mp_p; uint16_t mp_pad; /** @defgroup mdb_page Page Flags * @ingroup internal * Flags for the page headers. * @{ */ #define P_BRANCH 0x01 /**< branch page */ #define P_LEAF 0x02 /**< leaf page */ #define P_OVERFLOW 0x04 /**< overflow page */ #define P_META 0x08 /**< meta page */ #define P_DIRTY 0x10 /**< dirty page */ #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */ #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */ /** @} */ uint16_t mp_flags; /**< @ref mdb_page */ #define mp_lower mp_pb.pb.pb_lower #define mp_upper mp_pb.pb.pb_upper #define mp_pages mp_pb.pb_pages union { struct { indx_t pb_lower; /**< lower bound of free space */ indx_t pb_upper; /**< upper bound of free space */ } pb; uint32_t pb_pages; /**< number of overflow pages */ } mp_pb; indx_t mp_ptrs[1]; /**< dynamic size */ } MDB_page; /** Size of the page header, excluding dynamic data at the end */ #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs)) /** Address of first usable data byte in a page, after the header */ #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ)) /** Number of nodes on a page */ #define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1) /** The amount of space remaining in the page */ #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower) /** The percentage of space used in the page, in tenths of a percent. */ #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \ ((env)->me_psize - PAGEHDRSZ)) /** The minimum page fill factor, in tenths of a percent. * Pages emptier than this are candidates for merging. */ #define FILL_THRESHOLD 250 /** Test if a page is a leaf page */ #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF) /** Test if a page is a LEAF2 page */ #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2) /** Test if a page is a branch page */ #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH) /** Test if a page is an overflow page */ #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW) /** Test if a page is a sub page */ #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP) /** The number of overflow pages needed to store the given size. */ #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1) /** Header for a single key/data pair within a page. * We guarantee 2-byte alignment for nodes. */ typedef struct MDB_node { /** lo and hi are used for data size on leaf nodes and for * child pgno on branch nodes. On 64 bit platforms, flags * is also used for pgno. (Branch nodes have no flags). * They are in host byte order in case that lets some * accesses be optimized into a 32-bit word access. */ #define mn_lo mn_offset[BYTE_ORDER!=LITTLE_ENDIAN] #define mn_hi mn_offset[BYTE_ORDER==LITTLE_ENDIAN] /**< part of dsize or pgno */ unsigned short mn_offset[2]; /**< storage for #mn_lo and #mn_hi */ /** @defgroup mdb_node Node Flags * @ingroup internal * Flags for node headers. * @{ */ #define F_BIGDATA 0x01 /**< data put on overflow page */ #define F_SUBDATA 0x02 /**< data is a sub-database */ #define F_DUPDATA 0x04 /**< data has duplicates */ /** valid flags for #mdb_node_add() */ #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND) /** @} */ unsigned short mn_flags; /**< @ref mdb_node */ unsigned short mn_ksize; /**< key size */ char mn_data[1]; /**< key and data are appended here */ } MDB_node; /** Size of the node header, excluding dynamic data at the end */ #define NODESIZE offsetof(MDB_node, mn_data) /** Bit position of top word in page number, for shifting mn_flags */ #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0) /** Size of a node in a branch page with a given key. * This is just the node header plus the key, there is no data. */ #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size)) /** Size of a node in a leaf page with a given key and data. * This is node header plus key plus data size. */ #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size) /** Address of node \b i in page \b p */ #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i])) /** Address of the key for the node */ #define NODEKEY(node) (void *)((node)->mn_data) /** Address of the data for a node */ #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize) /** Get the page number pointed to by a branch node */ #define NODEPGNO(node) \ ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \ (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0)) /** Set the page number in a branch node */ #define SETPGNO(node,pgno) do { \ (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \ if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0) /** Get the size of the data in a leaf node */ #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16)) /** Set the size of the data for a leaf node */ #define SETDSZ(node,size) do { \ (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0) /** The size of a key in a node */ #define NODEKSZ(node) ((node)->mn_ksize) /** Copy a page number from src to dst */ #ifdef MISALIGNED_OK #define COPY_PGNO(dst,src) dst = src #else #if SIZE_MAX > 4294967295UL #define COPY_PGNO(dst,src) do { \ unsigned short *s, *d; \ s = (unsigned short *)&(src); \ d = (unsigned short *)&(dst); \ *d++ = *s++; \ *d++ = *s++; \ *d++ = *s++; \ *d = *s; \ } while (0) #else #define COPY_PGNO(dst,src) do { \ unsigned short *s, *d; \ s = (unsigned short *)&(src); \ d = (unsigned short *)&(dst); \ *d++ = *s++; \ *d = *s; \ } while (0) #endif #endif /** The address of a key in a LEAF2 page. * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs. * There are no node headers, keys are stored contiguously. */ #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks))) /** Set the \b node's key into \b key, if requested. */ #define MDB_SET_KEY(node, key) { if ((key) != NULL) { \ (key)->mv_size = NODEKSZ(node); (key)->mv_data = NODEKEY(node); } } /** Information about a single database in the environment. */ typedef struct MDB_db { uint32_t md_pad; /**< also ksize for LEAF2 pages */ uint16_t md_flags; /**< @ref mdb_open */ uint16_t md_depth; /**< depth of this tree */ pgno_t md_branch_pages; /**< number of internal pages */ pgno_t md_leaf_pages; /**< number of leaf pages */ pgno_t md_overflow_pages; /**< number of overflow pages */ size_t md_entries; /**< number of data items */ pgno_t md_root; /**< the root page of this tree */ } MDB_db; /** Handle for the DB used to track free pages. */ #define FREE_DBI 0 /** Handle for the default DB. */ #define MAIN_DBI 1 /** Meta page content. */ typedef struct MDB_meta { /** Stamp identifying this as an MDB file. It must be set * to #MDB_MAGIC. */ uint32_t mm_magic; /** Version number of this lock file. Must be set to #MDB_VERSION. */ uint32_t mm_version; void *mm_address; /**< address for fixed mapping */ size_t mm_mapsize; /**< size of mmap region */ MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */ /** The size of pages used in this DB */ #define mm_psize mm_dbs[0].md_pad /** Any persistent environment flags. @ref mdb_env */ #define mm_flags mm_dbs[0].md_flags pgno_t mm_last_pg; /**< last used page in file */ txnid_t mm_txnid; /**< txnid that committed this page */ } MDB_meta; /** Buffer for a stack-allocated dirty page. * The members define size and alignment, and silence type * aliasing warnings. They are not used directly; that could * mean incorrectly using several union members in parallel. */ typedef union MDB_pagebuf { char mb_raw[MDB_PAGESIZE]; MDB_page mb_page; struct { char mm_pad[PAGEHDRSZ]; MDB_meta mm_meta; } mb_metabuf; } MDB_pagebuf; /** Auxiliary DB info. * The information here is mostly static/read-only. There is * only a single copy of this record in the environment. */ typedef struct MDB_dbx { MDB_val md_name; /**< name of the database */ MDB_cmp_func *md_cmp; /**< function for comparing keys */ MDB_cmp_func *md_dcmp; /**< function for comparing data items */ MDB_rel_func *md_rel; /**< user relocate function */ void *md_relctx; /**< user-provided context for md_rel */ } MDB_dbx; /** A database transaction. * Every operation requires a transaction handle. */ struct MDB_txn { MDB_txn *mt_parent; /**< parent of a nested txn */ MDB_txn *mt_child; /**< nested txn under this txn */ pgno_t mt_next_pgno; /**< next unallocated page */ /** The ID of this transaction. IDs are integers incrementing from 1. * Only committed write transactions increment the ID. If a transaction * aborts, the ID may be re-used by the next writer. */ txnid_t mt_txnid; MDB_env *mt_env; /**< the DB environment */ /** The list of pages that became unused during this transaction. */ MDB_IDL mt_free_pgs; union { MDB_ID2L dirty_list; /**< modified pages */ MDB_reader *reader; /**< this thread's slot in the reader table */ } mt_u; /** Array of records for each DB known in the environment. */ MDB_dbx *mt_dbxs; /** Array of MDB_db records for each known DB */ MDB_db *mt_dbs; /** @defgroup mt_dbflag Transaction DB Flags * @ingroup internal * @{ */ #define DB_DIRTY 0x01 /**< DB was written in this txn */ #define DB_STALE 0x02 /**< DB record is older than txnID */ /** @} */ /** Array of cursors for each DB */ MDB_cursor **mt_cursors; /** Array of flags for each DB */ unsigned char *mt_dbflags; /** Number of DB records in use. This number only ever increments; * we don't decrement it when individual DB handles are closed. */ MDB_dbi mt_numdbs; /** @defgroup mdb_txn Transaction Flags * @ingroup internal * @{ */ #define MDB_TXN_RDONLY 0x01 /**< read-only transaction */ #define MDB_TXN_ERROR 0x02 /**< an error has occurred */ /** @} */ unsigned int mt_flags; /**< @ref mdb_txn */ /** Tracks which of the two meta pages was used at the start * of this transaction. */ unsigned int mt_toggle; }; /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty. * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to * raise this on a 64 bit machine. */ #define CURSOR_STACK 32 struct MDB_xcursor; /** Cursors are used for all DB operations */ struct MDB_cursor { /** Next cursor on this DB in this txn */ MDB_cursor *mc_next; /** Original cursor if this is a shadow */ MDB_cursor *mc_orig; /** Context used for databases with #MDB_DUPSORT, otherwise NULL */ struct MDB_xcursor *mc_xcursor; /** The transaction that owns this cursor */ MDB_txn *mc_txn; /** The database handle this cursor operates on */ MDB_dbi mc_dbi; /** The database record for this cursor */ MDB_db *mc_db; /** The database auxiliary record for this cursor */ MDB_dbx *mc_dbx; /** The @ref mt_dbflag for this database */ unsigned char *mc_dbflag; unsigned short mc_snum; /**< number of pushed pages */ unsigned short mc_top; /**< index of top page, normally mc_snum-1 */ /** @defgroup mdb_cursor Cursor Flags * @ingroup internal * Cursor state flags. * @{ */ #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */ #define C_EOF 0x02 /**< No more data */ #define C_SUB 0x04 /**< Cursor is a sub-cursor */ #define C_SHADOW 0x08 /**< Cursor is a dup from a parent txn */ #define C_ALLOCD 0x10 /**< Cursor was malloc'd */ #define C_SPLITTING 0x20 /**< Cursor is in page_split */ /** @} */ unsigned int mc_flags; /**< @ref mdb_cursor */ MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */ indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */ }; /** Context for sorted-dup records. * We could have gone to a fully recursive design, with arbitrarily * deep nesting of sub-databases. But for now we only handle these * levels - main DB, optional sub-DB, sorted-duplicate DB. */ typedef struct MDB_xcursor { /** A sub-cursor for traversing the Dup DB */ MDB_cursor mx_cursor; /** The database record for this Dup DB */ MDB_db mx_db; /** The auxiliary DB record for this Dup DB */ MDB_dbx mx_dbx; /** The @ref mt_dbflag for this Dup DB */ unsigned char mx_dbflag; } MDB_xcursor; /** A set of pages freed by an earlier transaction. */ typedef struct MDB_oldpages { /** Usually we only read one record from the FREEDB at a time, but * in case we read more, this will chain them together. */ struct MDB_oldpages *mo_next; /** The ID of the transaction in which these pages were freed. */ txnid_t mo_txnid; /** An #MDB_IDL of the pages */ pgno_t mo_pages[1]; /* dynamic */ } MDB_oldpages; /** The database environment. */ struct MDB_env { HANDLE me_fd; /**< The main data file */ HANDLE me_lfd; /**< The lock file */ HANDLE me_mfd; /**< just for writing the meta pages */ /** Failed to update the meta page. Probably an I/O error. */ #define MDB_FATAL_ERROR 0x80000000U uint32_t me_flags; /**< @ref mdb_env */ unsigned int me_psize; /**< size of a page, from #GET_PAGESIZE */ unsigned int me_maxreaders; /**< size of the reader table */ MDB_dbi me_numdbs; /**< number of DBs opened */ MDB_dbi me_maxdbs; /**< size of the DB table */ char *me_path; /**< path to the DB files */ char *me_map; /**< the memory map of the data file */ MDB_txninfo *me_txns; /**< the memory map of the lock file */ MDB_meta *me_metas[2]; /**< pointers to the two meta pages */ MDB_txn *me_txn; /**< current write transaction */ size_t me_mapsize; /**< size of the data memory map */ off_t me_size; /**< current file size */ pgno_t me_maxpg; /**< me_mapsize / me_psize */ txnid_t me_pgfirst; /**< ID of first old page record we used */ txnid_t me_pglast; /**< ID of last old page record we used */ MDB_dbx *me_dbxs; /**< array of static DB info */ uint16_t *me_dbflags; /**< array of DB flags */ MDB_oldpages *me_pghead; /**< list of old page records */ MDB_oldpages *me_pgfree; /**< list of page records to free */ pthread_key_t me_txkey; /**< thread-key for readers */ MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */ /** IDL of pages that became unused in a write txn */ MDB_IDL me_free_pgs; /** ID2L of pages that were written during a write txn */ MDB_ID2 me_dirty_list[MDB_IDL_UM_SIZE]; #ifdef _WIN32 HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */ HANDLE me_wmutex; #endif #ifdef USE_POSIX_SEM sem_t *me_rmutex; /* Apple doesn't support shared mutexes */ sem_t *me_wmutex; #endif }; /** max number of pages to commit in one writev() call */ #define MDB_COMMIT_PAGES 64 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES #undef MDB_COMMIT_PAGES #define MDB_COMMIT_PAGES IOV_MAX #endif static MDB_page *mdb_page_alloc(MDB_cursor *mc, int num); static MDB_page *mdb_page_new(MDB_cursor *mc, uint32_t flags, int num); static int mdb_page_touch(MDB_cursor *mc); static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp); static int mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify); #define MDB_PS_MODIFY 1 #define MDB_PS_ROOTONLY 2 static int mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags); static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst); #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */ static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno, unsigned int nflags); static int mdb_env_read_header(MDB_env *env, MDB_meta *meta); static int mdb_env_pick_meta(const MDB_env *env); static int mdb_env_write_meta(MDB_txn *txn); static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp); static int mdb_node_add(MDB_cursor *mc, indx_t indx, MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags); static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize); static void mdb_node_shrink(MDB_page *mp, indx_t indx); static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst); static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data); static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data); static size_t mdb_branch_size(MDB_env *env, MDB_val *key); static int mdb_rebalance(MDB_cursor *mc); static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key); static void mdb_cursor_pop(MDB_cursor *mc); static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp); static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf); static int mdb_cursor_sibling(MDB_cursor *mc, int move_right); static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp); static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data); static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data); static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx); static void mdb_xcursor_init0(MDB_cursor *mc); static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node); static int mdb_drop0(MDB_cursor *mc, int subs); static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi); /** @cond */ static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long; /** @endcond */ #ifdef _WIN32 static SECURITY_DESCRIPTOR mdb_null_sd; static SECURITY_ATTRIBUTES mdb_all_sa; static int mdb_sec_inited; #endif /** Return the library version info. */ char * mdb_version(int *major, int *minor, int *patch) { if (major) *major = MDB_VERSION_MAJOR; if (minor) *minor = MDB_VERSION_MINOR; if (patch) *patch = MDB_VERSION_PATCH; return MDB_VERSION_STRING; } /** Table of descriptions for MDB @ref errors */ static char *const mdb_errstr[] = { "MDB_KEYEXIST: Key/data pair already exists", "MDB_NOTFOUND: No matching key/data pair found", "MDB_PAGE_NOTFOUND: Requested page not found", "MDB_CORRUPTED: Located page was wrong type", "MDB_PANIC: Update of meta page failed", "MDB_VERSION_MISMATCH: Database environment version mismatch" }; char * mdb_strerror(int err) { if (!err) return ("Successful return: 0"); if (err >= MDB_KEYEXIST && err <= MDB_VERSION_MISMATCH) return mdb_errstr[err - MDB_KEYEXIST]; return strerror(err); } #if MDB_DEBUG /** Display a key in hexadecimal and return the address of the result. * @param[in] key the key to display * @param[in] buf the buffer to write into. Should always be #DKBUF. * @return The key in hexadecimal form. */ char * mdb_dkey(MDB_val *key, char *buf) { char *ptr = buf; unsigned char *c = key->mv_data; unsigned int i; if (key->mv_size > MAXKEYSIZE) return "MAXKEYSIZE"; /* may want to make this a dynamic check: if the key is mostly * printable characters, print it as-is instead of converting to hex. */ #if 1 buf[0] = '\0'; for (i=0; imv_size; i++) ptr += sprintf(ptr, "%02x", *c++); #else sprintf(buf, "%.*s", key->mv_size, key->mv_data); #endif return buf; } /** Display all the keys in the page. */ static void mdb_page_keys(MDB_page *mp) { MDB_node *node; unsigned int i, nkeys; MDB_val key; DKBUF; nkeys = NUMKEYS(mp); fprintf(stderr, "numkeys %d\n", nkeys); for (i=0; imn_ksize; key.mv_data = node->mn_data; fprintf(stderr, "key %d: %s\n", i, DKEY(&key)); } } void mdb_cursor_chk(MDB_cursor *mc) { unsigned int i; MDB_node *node; MDB_page *mp; if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return; for (i=0; imc_top; i++) { mp = mc->mc_pg[i]; node = NODEPTR(mp, mc->mc_ki[i]); if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno) printf("oops!\n"); } if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i])) printf("ack!\n"); } #endif #if MDB_DEBUG > 2 /** Count all the pages in each DB and in the freelist * and make sure it matches the actual number of pages * being used. */ static void mdb_audit(MDB_txn *txn) { MDB_cursor mc; MDB_val key, data; MDB_ID freecount, count; MDB_dbi i; int rc; freecount = 0; mdb_cursor_init(&mc, txn, FREE_DBI, NULL); while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0) freecount += *(MDB_ID *)data.mv_data; freecount += txn->mt_dbs[0].md_branch_pages + txn->mt_dbs[0].md_leaf_pages + txn->mt_dbs[0].md_overflow_pages; count = 0; for (i = 0; imt_numdbs; i++) { count += txn->mt_dbs[i].md_branch_pages + txn->mt_dbs[i].md_leaf_pages + txn->mt_dbs[i].md_overflow_pages; if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) { MDB_xcursor mx; mdb_cursor_init(&mc, txn, i, &mx); mdb_page_search(&mc, NULL, 0); do { unsigned j; MDB_page *mp; mp = mc.mc_pg[mc.mc_top]; for (j=0; jmn_flags & F_SUBDATA) { MDB_db db; memcpy(&db, NODEDATA(leaf), sizeof(db)); count += db.md_branch_pages + db.md_leaf_pages + db.md_overflow_pages; } } } while (mdb_cursor_sibling(&mc, 1) == 0); } } assert(freecount + count + 2 >= txn->mt_next_pgno - 1); } #endif int mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) { return txn->mt_dbxs[dbi].md_cmp(a, b); } int mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) { if (txn->mt_dbxs[dbi].md_dcmp) return txn->mt_dbxs[dbi].md_dcmp(a, b); else return EINVAL; /* too bad you can't distinguish this from a valid result */ } /** Allocate a single page. * Re-use old malloc'd pages first, otherwise just malloc. */ static MDB_page * mdb_page_malloc(MDB_cursor *mc) { MDB_page *ret; size_t sz = mc->mc_txn->mt_env->me_psize; if ((ret = mc->mc_txn->mt_env->me_dpages) != NULL) { VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz); VGMEMP_DEFINED(ret, sizeof(ret->mp_next)); mc->mc_txn->mt_env->me_dpages = ret->mp_next; } else if ((ret = malloc(sz)) != NULL) { VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz); } return ret; } /** Allocate pages for writing. * If there are free pages available from older transactions, they * will be re-used first. Otherwise a new page will be allocated. * @param[in] mc cursor A cursor handle identifying the transaction and * database for which we are allocating. * @param[in] num the number of pages to allocate. * @return Address of the allocated page(s). Requests for multiple pages * will always be satisfied by a single contiguous chunk of memory. */ static MDB_page * mdb_page_alloc(MDB_cursor *mc, int num) { MDB_txn *txn = mc->mc_txn; MDB_page *np; pgno_t pgno = P_INVALID; MDB_ID2 mid; /* The free list won't have any content at all until txn 2 has * committed. The pages freed by txn 2 will be unreferenced * after txn 3 commits, and so will be safe to re-use in txn 4. */ if (txn->mt_txnid > 3) { if (!txn->mt_env->me_pghead && txn->mt_dbs[FREE_DBI].md_root != P_INVALID) { /* See if there's anything in the free DB */ MDB_cursor m2; MDB_node *leaf; MDB_val data; txnid_t *kptr, oldest, last; mdb_cursor_init(&m2, txn, FREE_DBI, NULL); if (!txn->mt_env->me_pgfirst) { mdb_page_search(&m2, NULL, 0); leaf = NODEPTR(m2.mc_pg[m2.mc_top], 0); kptr = (txnid_t *)NODEKEY(leaf); last = *kptr; } else { MDB_val key; int rc, exact; again: exact = 0; last = txn->mt_env->me_pglast + 1; leaf = NULL; key.mv_data = &last; key.mv_size = sizeof(last); rc = mdb_cursor_set(&m2, &key, &data, MDB_SET, &exact); if (rc) goto none; last = *(txnid_t *)key.mv_data; } { unsigned int i; oldest = txn->mt_txnid - 1; for (i=0; imt_env->me_txns->mti_numreaders; i++) { txnid_t mr = txn->mt_env->me_txns->mti_readers[i].mr_txnid; if (mr && mr < oldest) oldest = mr; } } if (oldest > last) { /* It's usable, grab it. */ MDB_oldpages *mop; pgno_t *idl; if (!txn->mt_env->me_pgfirst) { mdb_node_read(txn, leaf, &data); } txn->mt_env->me_pglast = last; if (!txn->mt_env->me_pgfirst) txn->mt_env->me_pgfirst = last; idl = (MDB_ID *) data.mv_data; /* We might have a zero-length IDL due to freelist growth * during a prior commit */ if (!idl[0]) goto again; mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t)); mop->mo_next = txn->mt_env->me_pghead; mop->mo_txnid = last; txn->mt_env->me_pghead = mop; memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl)); #if MDB_DEBUG > 1 { unsigned int i; DPRINTF("IDL read txn %zu root %zu num %zu", mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]); for (i=0; imt_env->me_pghead) { MDB_oldpages *mop = txn->mt_env->me_pghead; if (num > 1) { /* FIXME: For now, always use fresh pages. We * really ought to search the free list for a * contiguous range. */ ; } else { /* peel pages off tail, so we only have to truncate the list */ pgno = MDB_IDL_LAST(mop->mo_pages); if (MDB_IDL_IS_RANGE(mop->mo_pages)) { mop->mo_pages[2]++; if (mop->mo_pages[2] > mop->mo_pages[1]) mop->mo_pages[0] = 0; } else { mop->mo_pages[0]--; } if (MDB_IDL_IS_ZERO(mop->mo_pages)) { txn->mt_env->me_pghead = mop->mo_next; if (mc->mc_dbi == FREE_DBI) { mop->mo_next = txn->mt_env->me_pgfree; txn->mt_env->me_pgfree = mop; } else { free(mop); } } } } } if (pgno == P_INVALID) { /* DB size is maxed out */ if (txn->mt_next_pgno + num >= txn->mt_env->me_maxpg) { DPUTS("DB size maxed out"); return NULL; } } if (txn->mt_env->me_dpages && num == 1) { np = txn->mt_env->me_dpages; VGMEMP_ALLOC(txn->mt_env, np, txn->mt_env->me_psize); VGMEMP_DEFINED(np, sizeof(np->mp_next)); txn->mt_env->me_dpages = np->mp_next; } else { size_t sz = txn->mt_env->me_psize * num; if ((np = malloc(sz)) == NULL) return NULL; VGMEMP_ALLOC(txn->mt_env, np, sz); } if (pgno == P_INVALID) { np->mp_pgno = txn->mt_next_pgno; txn->mt_next_pgno += num; } else { np->mp_pgno = pgno; } mid.mid = np->mp_pgno; mid.mptr = np; mdb_mid2l_insert(txn->mt_u.dirty_list, &mid); return np; } /** Copy a page: avoid copying unused portions of the page. * @param[in] dst page to copy into * @param[in] src page to copy from */ static void mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize) { dst->mp_flags = src->mp_flags | P_DIRTY; dst->mp_pages = src->mp_pages; if (IS_LEAF2(src)) { memcpy(dst->mp_ptrs, src->mp_ptrs, psize - PAGEHDRSZ - SIZELEFT(src)); } else { unsigned int i, nkeys = NUMKEYS(src); for (i=0; imp_ptrs[i] = src->mp_ptrs[i]; memcpy((char *)dst+src->mp_upper, (char *)src+src->mp_upper, psize - src->mp_upper); } } /** Touch a page: make it dirty and re-insert into tree with updated pgno. * @param[in] mc cursor pointing to the page to be touched * @return 0 on success, non-zero on failure. */ static int mdb_page_touch(MDB_cursor *mc) { MDB_page *mp = mc->mc_pg[mc->mc_top]; pgno_t pgno; if (!F_ISSET(mp->mp_flags, P_DIRTY)) { MDB_page *np; if ((np = mdb_page_alloc(mc, 1)) == NULL) return ENOMEM; DPRINTF("touched db %u page %zu -> %zu", mc->mc_dbi, mp->mp_pgno, np->mp_pgno); assert(mp->mp_pgno != np->mp_pgno); mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); if (SIZELEFT(mp)) { /* If page isn't full, just copy the used portion */ mdb_page_copy(np, mp, mc->mc_txn->mt_env->me_psize); } else { pgno = np->mp_pgno; memcpy(np, mp, mc->mc_txn->mt_env->me_psize); np->mp_pgno = pgno; np->mp_flags |= P_DIRTY; } mp = np; finish: /* Adjust other cursors pointing to mp */ if (mc->mc_flags & C_SUB) { MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi-1; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (m2 == mc) continue; m3 = &m2->mc_xcursor->mx_cursor; if (m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) { m3->mc_pg[mc->mc_top] = mp; } } } else { MDB_cursor *m2; for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; if (m2->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) { m2->mc_pg[mc->mc_top] = mp; } } } mc->mc_pg[mc->mc_top] = mp; /** If this page has a parent, update the parent to point to * this new page. */ if (mc->mc_top) SETPGNO(NODEPTR(mc->mc_pg[mc->mc_top-1], mc->mc_ki[mc->mc_top-1]), mp->mp_pgno); else mc->mc_db->md_root = mp->mp_pgno; } else if (mc->mc_txn->mt_parent) { MDB_page *np; MDB_ID2 mid; /* If txn has a parent, make sure the page is in our * dirty list. */ if (mc->mc_txn->mt_u.dirty_list[0].mid) { unsigned x = mdb_mid2l_search(mc->mc_txn->mt_u.dirty_list, mp->mp_pgno); if (x <= mc->mc_txn->mt_u.dirty_list[0].mid && mc->mc_txn->mt_u.dirty_list[x].mid == mp->mp_pgno) { if (mc->mc_txn->mt_u.dirty_list[x].mptr != mp) { mp = mc->mc_txn->mt_u.dirty_list[x].mptr; mc->mc_pg[mc->mc_top] = mp; } return 0; } } /* No - copy it */ np = mdb_page_malloc(mc); memcpy(np, mp, mc->mc_txn->mt_env->me_psize); mid.mid = np->mp_pgno; mid.mptr = np; mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &mid); mp = np; goto finish; } return 0; } int mdb_env_sync(MDB_env *env, int force) { int rc = 0; if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) { if (MDB_FDATASYNC(env->me_fd)) rc = ErrCode(); } return rc; } /** Make shadow copies of all of parent txn's cursors */ static int mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst) { MDB_cursor *mc, *m2; unsigned int i, j, size; for (i=0;imt_numdbs; i++) { if (src->mt_cursors[i]) { size = sizeof(MDB_cursor); if (src->mt_cursors[i]->mc_xcursor) size += sizeof(MDB_xcursor); for (m2 = src->mt_cursors[i]; m2; m2=m2->mc_next) { mc = malloc(size); if (!mc) return ENOMEM; mc->mc_orig = m2; mc->mc_txn = dst; mc->mc_dbi = i; mc->mc_db = &dst->mt_dbs[i]; mc->mc_dbx = m2->mc_dbx; mc->mc_dbflag = &dst->mt_dbflags[i]; mc->mc_snum = m2->mc_snum; mc->mc_top = m2->mc_top; mc->mc_flags = m2->mc_flags | C_SHADOW; for (j=0; jmc_snum; j++) { mc->mc_pg[j] = m2->mc_pg[j]; mc->mc_ki[j] = m2->mc_ki[j]; } if (m2->mc_xcursor) { MDB_xcursor *mx, *mx2; mx = (MDB_xcursor *)(mc+1); mc->mc_xcursor = mx; mx2 = m2->mc_xcursor; mx->mx_db = mx2->mx_db; mx->mx_dbx = mx2->mx_dbx; mx->mx_dbflag = mx2->mx_dbflag; mx->mx_cursor.mc_txn = dst; mx->mx_cursor.mc_dbi = mx2->mx_cursor.mc_dbi; mx->mx_cursor.mc_db = &mx->mx_db; mx->mx_cursor.mc_dbx = &mx->mx_dbx; mx->mx_cursor.mc_dbflag = &mx->mx_dbflag; mx->mx_cursor.mc_snum = mx2->mx_cursor.mc_snum; mx->mx_cursor.mc_top = mx2->mx_cursor.mc_top; mx->mx_cursor.mc_flags = mx2->mx_cursor.mc_flags | C_SHADOW; for (j=0; jmx_cursor.mc_snum; j++) { mx->mx_cursor.mc_pg[j] = mx2->mx_cursor.mc_pg[j]; mx->mx_cursor.mc_ki[j] = mx2->mx_cursor.mc_ki[j]; } } else { mc->mc_xcursor = NULL; } mc->mc_next = dst->mt_cursors[i]; dst->mt_cursors[i] = mc; } } } return MDB_SUCCESS; } /** Merge shadow cursors back into parent's */ static void mdb_cursor_merge(MDB_txn *txn) { MDB_dbi i; for (i=0; imt_numdbs; i++) { if (txn->mt_cursors[i]) { MDB_cursor *mc; while ((mc = txn->mt_cursors[i])) { txn->mt_cursors[i] = mc->mc_next; if (mc->mc_flags & C_SHADOW) { MDB_cursor *m2 = mc->mc_orig; unsigned int j; m2->mc_snum = mc->mc_snum; m2->mc_top = mc->mc_top; for (j=0; jmc_snum; j++) { m2->mc_pg[j] = mc->mc_pg[j]; m2->mc_ki[j] = mc->mc_ki[j]; } } if (mc->mc_flags & C_ALLOCD) free(mc); } } } } static void mdb_txn_reset0(MDB_txn *txn); /** Common code for #mdb_txn_begin() and #mdb_txn_renew(). * @param[in] txn the transaction handle to initialize * @return 0 on success, non-zero on failure. This can only * fail for read-only transactions, and then only if the * reader table is full. */ static int mdb_txn_renew0(MDB_txn *txn) { MDB_env *env = txn->mt_env; unsigned int i; /* Setup db info */ txn->mt_numdbs = env->me_numdbs; txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */ if (txn->mt_flags & MDB_TXN_RDONLY) { MDB_reader *r = pthread_getspecific(env->me_txkey); if (!r) { pid_t pid = getpid(); pthread_t tid = pthread_self(); LOCK_MUTEX_R(env); for (i=0; ime_txns->mti_numreaders; i++) if (env->me_txns->mti_readers[i].mr_pid == 0) break; if (i == env->me_maxreaders) { UNLOCK_MUTEX_R(env); return ENOMEM; } env->me_txns->mti_readers[i].mr_pid = pid; env->me_txns->mti_readers[i].mr_tid = tid; if (i >= env->me_txns->mti_numreaders) env->me_txns->mti_numreaders = i+1; UNLOCK_MUTEX_R(env); r = &env->me_txns->mti_readers[i]; pthread_setspecific(env->me_txkey, r); } txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid; txn->mt_toggle = txn->mt_txnid & 1; txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1; txn->mt_u.reader = r; } else { LOCK_MUTEX_W(env); txn->mt_txnid = env->me_txns->mti_txnid; txn->mt_toggle = txn->mt_txnid & 1; txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1; txn->mt_txnid++; #if MDB_DEBUG if (txn->mt_txnid == mdb_debug_start) mdb_debug = 1; #endif txn->mt_u.dirty_list = env->me_dirty_list; txn->mt_u.dirty_list[0].mid = 0; txn->mt_free_pgs = env->me_free_pgs; txn->mt_free_pgs[0] = 0; env->me_txn = txn; } /* Copy the DB info and flags */ memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db)); for (i=2; imt_numdbs; i++) txn->mt_dbs[i].md_flags = env->me_dbflags[i]; txn->mt_dbflags[0] = txn->mt_dbflags[1] = 0; if (txn->mt_numdbs > 2) memset(txn->mt_dbflags+2, DB_STALE, txn->mt_numdbs-2); return MDB_SUCCESS; } int mdb_txn_renew(MDB_txn *txn) { int rc; if (!txn) return EINVAL; if (txn->mt_env->me_flags & MDB_FATAL_ERROR) { DPUTS("environment had fatal error, must shutdown!"); return MDB_PANIC; } rc = mdb_txn_renew0(txn); if (rc == MDB_SUCCESS) { DPRINTF("renew txn %zu%c %p on mdbenv %p, root page %zu", txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root); } return rc; } int mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret) { MDB_txn *txn; int rc, size; if (env->me_flags & MDB_FATAL_ERROR) { DPUTS("environment had fatal error, must shutdown!"); return MDB_PANIC; } if (parent) { /* parent already has an active child txn */ if (parent->mt_child) { return EINVAL; } } size = sizeof(MDB_txn) + env->me_maxdbs * (sizeof(MDB_db)+1); if (!(flags & MDB_RDONLY)) size += env->me_maxdbs * sizeof(MDB_cursor *); if ((txn = calloc(1, size)) == NULL) { DPRINTF("calloc: %s", strerror(ErrCode())); return ENOMEM; } txn->mt_dbs = (MDB_db *)(txn+1); if (flags & MDB_RDONLY) { txn->mt_flags |= MDB_TXN_RDONLY; txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs); } else { txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs); txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs); } txn->mt_env = env; if (parent) { txn->mt_free_pgs = mdb_midl_alloc(); if (!txn->mt_free_pgs) { free(txn); return ENOMEM; } txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE); if (!txn->mt_u.dirty_list) { free(txn->mt_free_pgs); free(txn); return ENOMEM; } txn->mt_txnid = parent->mt_txnid; txn->mt_toggle = parent->mt_toggle; txn->mt_u.dirty_list[0].mid = 0; txn->mt_free_pgs[0] = 0; txn->mt_next_pgno = parent->mt_next_pgno; parent->mt_child = txn; txn->mt_parent = parent; txn->mt_numdbs = parent->mt_numdbs; txn->mt_dbxs = parent->mt_dbxs; memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db)); memcpy(txn->mt_dbflags, parent->mt_dbflags, txn->mt_numdbs); mdb_cursor_shadow(parent, txn); rc = 0; } else { rc = mdb_txn_renew0(txn); } if (rc) free(txn); else { *ret = txn; DPRINTF("begin txn %zu%c %p on mdbenv %p, root page %zu", txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root); } return rc; } /** Common code for #mdb_txn_reset() and #mdb_txn_abort(). * @param[in] txn the transaction handle to reset */ static void mdb_txn_reset0(MDB_txn *txn) { MDB_env *env = txn->mt_env; if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { txn->mt_u.reader->mr_txnid = 0; } else { MDB_oldpages *mop; MDB_page *dp; unsigned int i; /* close(free) all cursors */ for (i=0; imt_numdbs; i++) { if (txn->mt_cursors[i]) { MDB_cursor *mc; while ((mc = txn->mt_cursors[i])) { txn->mt_cursors[i] = mc->mc_next; if (mc->mc_flags & C_ALLOCD) free(mc); } } } /* return all dirty pages to dpage list */ for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) { dp = txn->mt_u.dirty_list[i].mptr; if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) { dp->mp_next = txn->mt_env->me_dpages; VGMEMP_FREE(txn->mt_env, dp); txn->mt_env->me_dpages = dp; } else { /* large pages just get freed directly */ VGMEMP_FREE(txn->mt_env, dp); free(dp); } } if (txn->mt_parent) { txn->mt_parent->mt_child = NULL; free(txn->mt_free_pgs); free(txn->mt_u.dirty_list); return; } else { if (mdb_midl_shrink(&txn->mt_free_pgs)) env->me_free_pgs = txn->mt_free_pgs; } while ((mop = txn->mt_env->me_pghead)) { txn->mt_env->me_pghead = mop->mo_next; free(mop); } txn->mt_env->me_pgfirst = 0; txn->mt_env->me_pglast = 0; env->me_txn = NULL; /* The writer mutex was locked in mdb_txn_begin. */ UNLOCK_MUTEX_W(env); } } void mdb_txn_reset(MDB_txn *txn) { if (txn == NULL) return; DPRINTF("reset txn %zu%c %p on mdbenv %p, root page %zu", txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *) txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root); mdb_txn_reset0(txn); } void mdb_txn_abort(MDB_txn *txn) { if (txn == NULL) return; DPRINTF("abort txn %zu%c %p on mdbenv %p, root page %zu", txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root); if (txn->mt_child) mdb_txn_abort(txn->mt_child); mdb_txn_reset0(txn); free(txn); } int mdb_txn_commit(MDB_txn *txn) { int n, done; unsigned int i; ssize_t rc; off_t size; MDB_page *dp; MDB_env *env; pgno_t next, freecnt; MDB_cursor mc; assert(txn != NULL); assert(txn->mt_env != NULL); if (txn->mt_child) { mdb_txn_commit(txn->mt_child); txn->mt_child = NULL; } env = txn->mt_env; if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { if (txn->mt_numdbs > env->me_numdbs) { /* update the DB flags */ MDB_dbi i; for (i = env->me_numdbs; imt_numdbs; i++) env->me_dbflags[i] = txn->mt_dbs[i].md_flags; env->me_numdbs = i; } mdb_txn_abort(txn); return MDB_SUCCESS; } if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) { DPUTS("error flag is set, can't commit"); if (txn->mt_parent) txn->mt_parent->mt_flags |= MDB_TXN_ERROR; mdb_txn_abort(txn); return EINVAL; } /* Merge (and close) our cursors with parent's */ mdb_cursor_merge(txn); if (txn->mt_parent) { MDB_db *ip, *jp; MDB_dbi i; unsigned x, y; MDB_ID2L dst, src; /* Update parent's DB table */ ip = &txn->mt_parent->mt_dbs[2]; jp = &txn->mt_dbs[2]; for (i = 2; i < txn->mt_numdbs; i++) { if (ip->md_root != jp->md_root) *ip = *jp; ip++; jp++; } txn->mt_parent->mt_numdbs = txn->mt_numdbs; /* Append our free list to parent's */ mdb_midl_append_list(&txn->mt_parent->mt_free_pgs, txn->mt_free_pgs); mdb_midl_free(txn->mt_free_pgs); /* Merge our dirty list with parent's */ dst = txn->mt_parent->mt_u.dirty_list; src = txn->mt_u.dirty_list; x = mdb_mid2l_search(dst, src[1].mid); for (y=1; y<=src[0].mid; y++) { while (x <= dst[0].mid && dst[x].mid != src[y].mid) x++; if (x > dst[0].mid) break; free(dst[x].mptr); dst[x].mptr = src[y].mptr; } x = dst[0].mid; for (; y<=src[0].mid; y++) { if (++x >= MDB_IDL_UM_MAX) { mdb_txn_abort(txn); return ENOMEM; } dst[x] = src[y]; } dst[0].mid = x; free(txn->mt_u.dirty_list); txn->mt_parent->mt_child = NULL; free(txn); return MDB_SUCCESS; } if (txn != env->me_txn) { DPUTS("attempt to commit unknown transaction"); mdb_txn_abort(txn); return EINVAL; } if (!txn->mt_u.dirty_list[0].mid) goto done; DPRINTF("committing txn %zu %p on mdbenv %p, root page %zu", txn->mt_txnid, (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root); /* Update DB root pointers. Their pages have already been * touched so this is all in-place and cannot fail. */ if (txn->mt_numdbs > 2) { MDB_dbi i; MDB_val data; data.mv_size = sizeof(MDB_db); mdb_cursor_init(&mc, txn, MAIN_DBI, NULL); for (i = 2; i < txn->mt_numdbs; i++) { if (txn->mt_dbflags[i] & DB_DIRTY) { data.mv_data = &txn->mt_dbs[i]; mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0); } } } mdb_cursor_init(&mc, txn, FREE_DBI, NULL); /* should only be one record now */ if (env->me_pghead) { /* make sure first page of freeDB is touched and on freelist */ mdb_page_search(&mc, NULL, MDB_PS_MODIFY); } /* Delete IDLs we used from the free list */ if (env->me_pgfirst) { txnid_t cur; MDB_val key; int exact = 0; key.mv_size = sizeof(cur); for (cur = env->me_pgfirst; cur <= env->me_pglast; cur++) { key.mv_data = &cur; mdb_cursor_set(&mc, &key, NULL, MDB_SET, &exact); rc = mdb_cursor_del(&mc, 0); if (rc) { mdb_txn_abort(txn); return rc; } } env->me_pgfirst = 0; env->me_pglast = 0; } /* save to free list */ free2: freecnt = txn->mt_free_pgs[0]; if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) { MDB_val key, data; /* make sure last page of freeDB is touched and on freelist */ key.mv_size = MAXKEYSIZE+1; key.mv_data = NULL; mdb_page_search(&mc, &key, MDB_PS_MODIFY); mdb_midl_sort(txn->mt_free_pgs); #if MDB_DEBUG > 1 { unsigned int i; MDB_IDL idl = txn->mt_free_pgs; DPRINTF("IDL write txn %zu root %zu num %zu", txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]); for (i=0; imt_txnid; data.mv_data = txn->mt_free_pgs; /* The free list can still grow during this call, * despite the pre-emptive touches above. So check * and make sure the entire thing got written. */ do { freecnt = txn->mt_free_pgs[0]; data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs); rc = mdb_cursor_put(&mc, &key, &data, 0); if (rc) { mdb_txn_abort(txn); return rc; } } while (freecnt != txn->mt_free_pgs[0]); } /* should only be one record now */ again: if (env->me_pghead) { MDB_val key, data; MDB_oldpages *mop; pgno_t orig; txnid_t id; mop = env->me_pghead; id = mop->mo_txnid; key.mv_size = sizeof(id); key.mv_data = &id; data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages); data.mv_data = mop->mo_pages; orig = mop->mo_pages[0]; /* These steps may grow the freelist again * due to freed overflow pages... */ mdb_cursor_put(&mc, &key, &data, 0); if (mop == env->me_pghead && env->me_pghead->mo_txnid == id) { /* could have been used again here */ if (mop->mo_pages[0] != orig) { data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages); data.mv_data = mop->mo_pages; id = mop->mo_txnid; mdb_cursor_put(&mc, &key, &data, 0); } env->me_pghead = NULL; free(mop); } else { /* was completely used up */ mdb_cursor_del(&mc, 0); if (env->me_pghead) goto again; } env->me_pgfirst = 0; env->me_pglast = 0; } while (env->me_pgfree) { MDB_oldpages *mop = env->me_pgfree; env->me_pgfree = mop->mo_next; free(mop);; } /* Check for growth of freelist again */ if (freecnt != txn->mt_free_pgs[0]) goto free2; if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) { if (mdb_midl_shrink(&txn->mt_free_pgs)) env->me_free_pgs = txn->mt_free_pgs; } #if MDB_DEBUG > 2 mdb_audit(txn); #endif /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done. */ next = 0; i = 1; do { #ifdef _WIN32 /* Windows actually supports scatter/gather I/O, but only on * unbuffered file handles. Since we're relying on the OS page * cache for all our data, that's self-defeating. So we just * write pages one at a time. We use the ov structure to set * the write offset, to at least save the overhead of a Seek * system call. */ OVERLAPPED ov; memset(&ov, 0, sizeof(ov)); for (; i<=txn->mt_u.dirty_list[0].mid; i++) { size_t wsize; dp = txn->mt_u.dirty_list[i].mptr; DPRINTF("committing page %zu", dp->mp_pgno); size = dp->mp_pgno * env->me_psize; ov.Offset = size & 0xffffffff; ov.OffsetHigh = size >> 16; ov.OffsetHigh >>= 16; /* clear dirty flag */ dp->mp_flags &= ~P_DIRTY; wsize = env->me_psize; if (IS_OVERFLOW(dp)) wsize *= dp->mp_pages; rc = WriteFile(env->me_fd, dp, wsize, NULL, &ov); if (!rc) { n = ErrCode(); DPRINTF("WriteFile: %d", n); mdb_txn_abort(txn); return n; } } done = 1; #else struct iovec iov[MDB_COMMIT_PAGES]; n = 0; done = 1; size = 0; for (; i<=txn->mt_u.dirty_list[0].mid; i++) { dp = txn->mt_u.dirty_list[i].mptr; if (dp->mp_pgno != next) { if (n) { rc = writev(env->me_fd, iov, n); if (rc != size) { n = ErrCode(); if (rc > 0) DPUTS("short write, filesystem full?"); else DPRINTF("writev: %s", strerror(n)); mdb_txn_abort(txn); return n; } n = 0; size = 0; } lseek(env->me_fd, dp->mp_pgno * env->me_psize, SEEK_SET); next = dp->mp_pgno; } DPRINTF("committing page %zu", dp->mp_pgno); iov[n].iov_len = env->me_psize; if (IS_OVERFLOW(dp)) iov[n].iov_len *= dp->mp_pages; iov[n].iov_base = (char *)dp; size += iov[n].iov_len; next = dp->mp_pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1); /* clear dirty flag */ dp->mp_flags &= ~P_DIRTY; if (++n >= MDB_COMMIT_PAGES) { done = 0; i++; break; } } if (n == 0) break; rc = writev(env->me_fd, iov, n); if (rc != size) { n = ErrCode(); if (rc > 0) DPUTS("short write, filesystem full?"); else DPRINTF("writev: %s", strerror(n)); mdb_txn_abort(txn); return n; } #endif } while (!done); /* Drop the dirty pages. */ for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) { dp = txn->mt_u.dirty_list[i].mptr; if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) { dp->mp_next = txn->mt_env->me_dpages; VGMEMP_FREE(txn->mt_env, dp); txn->mt_env->me_dpages = dp; } else { VGMEMP_FREE(txn->mt_env, dp); free(dp); } txn->mt_u.dirty_list[i].mid = 0; } txn->mt_u.dirty_list[0].mid = 0; if ((n = mdb_env_sync(env, 0)) != 0 || (n = mdb_env_write_meta(txn)) != MDB_SUCCESS) { mdb_txn_abort(txn); return n; } done: env->me_txn = NULL; if (txn->mt_numdbs > env->me_numdbs) { /* update the DB flags */ MDB_dbi i; for (i = env->me_numdbs; imt_numdbs; i++) env->me_dbflags[i] = txn->mt_dbs[i].md_flags; env->me_numdbs = i; } UNLOCK_MUTEX_W(env); free(txn); return MDB_SUCCESS; } /** Read the environment parameters of a DB environment before * mapping it into memory. * @param[in] env the environment handle * @param[out] meta address of where to store the meta information * @return 0 on success, non-zero on failure. */ static int mdb_env_read_header(MDB_env *env, MDB_meta *meta) { MDB_pagebuf pbuf; MDB_page *p; MDB_meta *m; int rc, err; /* We don't know the page size yet, so use a minimum value. */ #ifdef _WIN32 if (!ReadFile(env->me_fd, &pbuf, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0) #else if ((rc = read(env->me_fd, &pbuf, MDB_PAGESIZE)) == 0) #endif { return ENOENT; } else if (rc != MDB_PAGESIZE) { err = ErrCode(); if (rc > 0) err = EINVAL; DPRINTF("read: %s", strerror(err)); return err; } p = (MDB_page *)&pbuf; if (!F_ISSET(p->mp_flags, P_META)) { DPRINTF("page %zu not a meta page", p->mp_pgno); return EINVAL; } m = METADATA(p); if (m->mm_magic != MDB_MAGIC) { DPUTS("meta has invalid magic"); return EINVAL; } if (m->mm_version != MDB_VERSION) { DPRINTF("database is version %u, expected version %u", m->mm_version, MDB_VERSION); return MDB_VERSION_MISMATCH; } memcpy(meta, m, sizeof(*m)); return 0; } /** Write the environment parameters of a freshly created DB environment. * @param[in] env the environment handle * @param[out] meta address of where to store the meta information * @return 0 on success, non-zero on failure. */ static int mdb_env_init_meta(MDB_env *env, MDB_meta *meta) { MDB_page *p, *q; MDB_meta *m; int rc; unsigned int psize; DPUTS("writing new meta page"); GET_PAGESIZE(psize); meta->mm_magic = MDB_MAGIC; meta->mm_version = MDB_VERSION; meta->mm_psize = psize; meta->mm_last_pg = 1; meta->mm_flags = env->me_flags & 0xffff; meta->mm_flags |= MDB_INTEGERKEY; meta->mm_dbs[0].md_root = P_INVALID; meta->mm_dbs[1].md_root = P_INVALID; p = calloc(2, psize); p->mp_pgno = 0; p->mp_flags = P_META; m = METADATA(p); memcpy(m, meta, sizeof(*meta)); q = (MDB_page *)((char *)p + psize); q->mp_pgno = 1; q->mp_flags = P_META; m = METADATA(q); memcpy(m, meta, sizeof(*meta)); #ifdef _WIN32 { DWORD len; rc = WriteFile(env->me_fd, p, psize * 2, &len, NULL); rc = (len == psize * 2) ? MDB_SUCCESS : ErrCode(); } #else rc = write(env->me_fd, p, psize * 2); rc = (rc == (int)psize * 2) ? MDB_SUCCESS : ErrCode(); #endif free(p); return rc; } /** Update the environment info to commit a transaction. * @param[in] txn the transaction that's being committed * @return 0 on success, non-zero on failure. */ static int mdb_env_write_meta(MDB_txn *txn) { MDB_env *env; MDB_meta meta, metab; off_t off; int rc, len, toggle; char *ptr; #ifdef _WIN32 OVERLAPPED ov; #endif assert(txn != NULL); assert(txn->mt_env != NULL); toggle = !txn->mt_toggle; DPRINTF("writing meta page %d for root page %zu", toggle, txn->mt_dbs[MAIN_DBI].md_root); env = txn->mt_env; metab.mm_txnid = env->me_metas[toggle]->mm_txnid; metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg; ptr = (char *)&meta; off = offsetof(MDB_meta, mm_dbs[0].md_depth); len = sizeof(MDB_meta) - off; ptr += off; meta.mm_dbs[0] = txn->mt_dbs[0]; meta.mm_dbs[1] = txn->mt_dbs[1]; meta.mm_last_pg = txn->mt_next_pgno - 1; meta.mm_txnid = txn->mt_txnid; if (toggle) off += env->me_psize; off += PAGEHDRSZ; /* Write to the SYNC fd */ #ifdef _WIN32 { memset(&ov, 0, sizeof(ov)); ov.Offset = off; WriteFile(env->me_mfd, ptr, len, (DWORD *)&rc, &ov); } #else rc = pwrite(env->me_mfd, ptr, len, off); #endif if (rc != len) { int r2; rc = ErrCode(); DPUTS("write failed, disk error?"); /* On a failure, the pagecache still contains the new data. * Write some old data back, to prevent it from being used. * Use the non-SYNC fd; we know it will fail anyway. */ meta.mm_last_pg = metab.mm_last_pg; meta.mm_txnid = metab.mm_txnid; #ifdef _WIN32 WriteFile(env->me_fd, ptr, len, NULL, &ov); #else r2 = pwrite(env->me_fd, ptr, len, off); #endif env->me_flags |= MDB_FATAL_ERROR; return rc; } /* Memory ordering issues are irrelevant; since the entire writer * is wrapped by wmutex, all of these changes will become visible * after the wmutex is unlocked. Since the DB is multi-version, * readers will get consistent data regardless of how fresh or * how stale their view of these values is. */ txn->mt_env->me_txns->mti_txnid = txn->mt_txnid; return MDB_SUCCESS; } /** Check both meta pages to see which one is newer. * @param[in] env the environment handle * @return meta toggle (0 or 1). */ static int mdb_env_pick_meta(const MDB_env *env) { return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid); } int mdb_env_create(MDB_env **env) { MDB_env *e; e = calloc(1, sizeof(MDB_env)); if (!e) return ENOMEM; e->me_free_pgs = mdb_midl_alloc(); if (!e->me_free_pgs) { free(e); return ENOMEM; } e->me_maxreaders = DEFAULT_READERS; e->me_maxdbs = 2; e->me_fd = INVALID_HANDLE_VALUE; e->me_lfd = INVALID_HANDLE_VALUE; e->me_mfd = INVALID_HANDLE_VALUE; VGMEMP_CREATE(e,0,0); *env = e; return MDB_SUCCESS; } int mdb_env_set_mapsize(MDB_env *env, size_t size) { if (env->me_map) return EINVAL; env->me_mapsize = size; if (env->me_psize) env->me_maxpg = env->me_mapsize / env->me_psize; return MDB_SUCCESS; } int mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs) { if (env->me_map) return EINVAL; env->me_maxdbs = dbs; return MDB_SUCCESS; } int mdb_env_set_maxreaders(MDB_env *env, unsigned int readers) { if (env->me_map || readers < 1) return EINVAL; env->me_maxreaders = readers; return MDB_SUCCESS; } int mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers) { if (!env || !readers) return EINVAL; *readers = env->me_maxreaders; return MDB_SUCCESS; } /** Further setup required for opening an MDB environment */ static int mdb_env_open2(MDB_env *env, unsigned int flags) { int i, newenv = 0; MDB_meta meta; MDB_page *p; env->me_flags = flags; memset(&meta, 0, sizeof(meta)); if ((i = mdb_env_read_header(env, &meta)) != 0) { if (i != ENOENT) return i; DPUTS("new mdbenv"); newenv = 1; } if (!env->me_mapsize) { env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize; } #ifdef _WIN32 { HANDLE mh; LONG sizelo, sizehi; sizelo = env->me_mapsize & 0xffffffff; sizehi = env->me_mapsize >> 16; /* pointless on WIN32, only needed on W64 */ sizehi >>= 16; /* Windows won't create mappings for zero length files. * Just allocate the maxsize right now. */ if (newenv) { SetFilePointer(env->me_fd, sizelo, sizehi ? &sizehi : NULL, 0); if (!SetEndOfFile(env->me_fd)) return ErrCode(); SetFilePointer(env->me_fd, 0, NULL, 0); } mh = CreateFileMapping(env->me_fd, NULL, PAGE_READONLY, sizehi, sizelo, NULL); if (!mh) return ErrCode(); env->me_map = MapViewOfFileEx(mh, FILE_MAP_READ, 0, 0, env->me_mapsize, meta.mm_address); CloseHandle(mh); if (!env->me_map) return ErrCode(); } #else i = MAP_SHARED; if (meta.mm_address && (flags & MDB_FIXEDMAP)) i |= MAP_FIXED; env->me_map = mmap(meta.mm_address, env->me_mapsize, PROT_READ, i, env->me_fd, 0); if (env->me_map == MAP_FAILED) { env->me_map = NULL; return ErrCode(); } #endif if (newenv) { meta.mm_mapsize = env->me_mapsize; if (flags & MDB_FIXEDMAP) meta.mm_address = env->me_map; i = mdb_env_init_meta(env, &meta); if (i != MDB_SUCCESS) { munmap(env->me_map, env->me_mapsize); return i; } } env->me_psize = meta.mm_psize; env->me_maxpg = env->me_mapsize / env->me_psize; p = (MDB_page *)env->me_map; env->me_metas[0] = METADATA(p); env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize); #if MDB_DEBUG { int toggle = mdb_env_pick_meta(env); MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI]; DPRINTF("opened database version %u, pagesize %u", env->me_metas[0]->mm_version, env->me_psize); DPRINTF("using meta page %d", toggle); DPRINTF("depth: %u", db->md_depth); DPRINTF("entries: %zu", db->md_entries); DPRINTF("branch pages: %zu", db->md_branch_pages); DPRINTF("leaf pages: %zu", db->md_leaf_pages); DPRINTF("overflow pages: %zu", db->md_overflow_pages); DPRINTF("root: %zu", db->md_root); } #endif return MDB_SUCCESS; } /** Release a reader thread's slot in the reader lock table. * This function is called automatically when a thread exits. * @param[in] ptr This points to the slot in the reader lock table. */ static void mdb_env_reader_dest(void *ptr) { MDB_reader *reader = ptr; reader->mr_txnid = 0; reader->mr_pid = 0; reader->mr_tid = 0; } #ifdef _WIN32 /** Junk for arranging thread-specific callbacks on Windows. This is * necessarily platform and compiler-specific. Windows supports up * to 1088 keys. Let's assume nobody opens more than 64 environments * in a single process, for now. They can override this if needed. */ #ifndef MAX_TLS_KEYS #define MAX_TLS_KEYS 64 #endif static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS]; static int mdb_tls_nkeys; static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr) { int i; switch(reason) { case DLL_PROCESS_ATTACH: break; case DLL_THREAD_ATTACH: break; case DLL_THREAD_DETACH: for (i=0; ime_txns->mti_txnid = env->me_metas[toggle]->mm_txnid; #ifdef _WIN32 { OVERLAPPED ov; /* First acquire a shared lock. The Unlock will * then release the existing exclusive lock. */ memset(&ov, 0, sizeof(ov)); LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov); UnlockFile(env->me_lfd, 0, 0, 1, 0); } #else { struct flock lock_info; /* The shared lock replaces the existing lock */ memset((void *)&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_RDLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = 0; lock_info.l_len = 1; fcntl(env->me_lfd, F_SETLK, &lock_info); } #endif } #if defined(_WIN32) || defined(USE_POSIX_SEM) /* * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code * * @(#) $Revision: 5.1 $ * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $ * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $ * * http://www.isthe.com/chongo/tech/comp/fnv/index.html * *** * * Please do not copyright this code. This code is in the public domain. * * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. * * By: * chongo /\oo/\ * http://www.isthe.com/chongo/ * * Share and Enjoy! :-) */ typedef unsigned long long mdb_hash_t; #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL) /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer * @param[in] str string to hash * @param[in] hval initial value for hash * @return 64 bit hash * * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the * hval arg on the first call. */ static mdb_hash_t mdb_hash_val(MDB_val *val, mdb_hash_t hval) { unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */ unsigned char *end = s + val->mv_size; /* * FNV-1a hash each octet of the string */ while (s < end) { /* xor the bottom with the current octet */ hval ^= (mdb_hash_t)*s++; /* multiply by the 64 bit FNV magic prime mod 2^64 */ hval += (hval << 1) + (hval << 4) + (hval << 5) + (hval << 7) + (hval << 8) + (hval << 40); } /* return our new hash value */ return hval; } /** Hash the string and output the hash in hex. * @param[in] str string to hash * @param[out] hexbuf an array of 17 chars to hold the hash */ static void mdb_hash_hex(MDB_val *val, char *hexbuf) { int i; mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT); for (i=0; i<8; i++) { hexbuf += sprintf(hexbuf, "%02x", (unsigned int)h & 0xff); h >>= 8; } } #endif /** Open and/or initialize the lock region for the environment. * @param[in] env The MDB environment. * @param[in] lpath The pathname of the file used for the lock region. * @param[in] mode The Unix permissions for the file, if we create it. * @param[out] excl Set to true if we got an exclusive lock on the region. * @return 0 on success, non-zero on failure. */ static int mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl) { int rc; off_t size, rsize; *excl = 0; #ifdef _WIN32 if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) { rc = ErrCode(); return rc; } /* Try to get exclusive lock. If we succeed, then * nobody is using the lock region and we should initialize it. */ { if (LockFile(env->me_lfd, 0, 0, 1, 0)) { *excl = 1; } else { OVERLAPPED ov; memset(&ov, 0, sizeof(ov)); if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) { rc = ErrCode(); goto fail; } } } size = GetFileSize(env->me_lfd, NULL); #else #if !(O_CLOEXEC) { int fdflags; if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) return ErrCode(); /* Lose record locks when exec*() */ if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0) fcntl(env->me_lfd, F_SETFD, fdflags); } #else /* O_CLOEXEC on Linux: Open file and set FD_CLOEXEC atomically */ if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1) return ErrCode(); #endif /* Try to get exclusive lock. If we succeed, then * nobody is using the lock region and we should initialize it. */ { struct flock lock_info; memset((void *)&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_WRLCK; lock_info.l_whence = SEEK_SET; lock_info.l_start = 0; lock_info.l_len = 1; rc = fcntl(env->me_lfd, F_SETLK, &lock_info); if (rc == 0) { *excl = 1; } else { lock_info.l_type = F_RDLCK; rc = fcntl(env->me_lfd, F_SETLKW, &lock_info); if (rc) { rc = ErrCode(); goto fail; } } } size = lseek(env->me_lfd, 0, SEEK_END); #endif rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo); if (size < rsize && *excl) { #ifdef _WIN32 SetFilePointer(env->me_lfd, rsize, NULL, 0); if (!SetEndOfFile(env->me_lfd)) { rc = ErrCode(); goto fail; } #else if (ftruncate(env->me_lfd, rsize) != 0) { rc = ErrCode(); goto fail; } #endif } else { rsize = size; size = rsize - sizeof(MDB_txninfo); env->me_maxreaders = size/sizeof(MDB_reader) + 1; } { #ifdef _WIN32 HANDLE mh; mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE, 0, 0, NULL); if (!mh) { rc = ErrCode(); goto fail; } env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL); CloseHandle(mh); if (!env->me_txns) { rc = ErrCode(); goto fail; } #else void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED, env->me_lfd, 0); if (m == MAP_FAILED) { env->me_txns = NULL; rc = ErrCode(); goto fail; } env->me_txns = m; #endif } if (*excl) { #ifdef _WIN32 BY_HANDLE_FILE_INFORMATION stbuf; struct { DWORD volume; DWORD nhigh; DWORD nlow; } idbuf; MDB_val val; char hexbuf[17]; if (!mdb_sec_inited) { InitializeSecurityDescriptor(&mdb_null_sd, SECURITY_DESCRIPTOR_REVISION); SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE); mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES); mdb_all_sa.bInheritHandle = FALSE; mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd; mdb_sec_inited = 1; } GetFileInformationByHandle(env->me_lfd, &stbuf); idbuf.volume = stbuf.dwVolumeSerialNumber; idbuf.nhigh = stbuf.nFileIndexHigh; idbuf.nlow = stbuf.nFileIndexLow; val.mv_data = &idbuf; val.mv_size = sizeof(idbuf); mdb_hash_hex(&val, hexbuf); sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", hexbuf); env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname); if (!env->me_rmutex) { rc = ErrCode(); goto fail; } sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", hexbuf); env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname); if (!env->me_wmutex) { rc = ErrCode(); goto fail; } #else /* _WIN32 */ #ifdef USE_POSIX_SEM struct stat stbuf; struct { dev_t dev; ino_t ino; } idbuf; MDB_val val; char hexbuf[17]; fstat(env->me_lfd, &stbuf); idbuf.dev = stbuf.st_dev; idbuf.ino = stbuf.st_ino; val.mv_data = &idbuf; val.mv_size = sizeof(idbuf); mdb_hash_hex(&val, hexbuf); sprintf(env->me_txns->mti_rmname, "/MDBr%s", hexbuf); if (sem_unlink(env->me_txns->mti_rmname)) { rc = ErrCode(); if (rc != ENOENT && rc != EINVAL) goto fail; } env->me_rmutex = sem_open(env->me_txns->mti_rmname, O_CREAT, mode, 1); if (!env->me_rmutex) { rc = ErrCode(); goto fail; } sprintf(env->me_txns->mti_wmname, "/MDBw%s", hexbuf); if (sem_unlink(env->me_txns->mti_wmname)) { rc = ErrCode(); if (rc != ENOENT && rc != EINVAL) goto fail; } env->me_wmutex = sem_open(env->me_txns->mti_wmname, O_CREAT, mode, 1); if (!env->me_wmutex) { rc = ErrCode(); goto fail; } #else /* USE_POSIX_SEM */ pthread_mutexattr_t mattr; pthread_mutexattr_init(&mattr); rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED); if (rc) { goto fail; } pthread_mutex_init(&env->me_txns->mti_mutex, &mattr); pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr); #endif /* USE_POSIX_SEM */ #endif /* _WIN32 */ env->me_txns->mti_version = MDB_VERSION; env->me_txns->mti_magic = MDB_MAGIC; env->me_txns->mti_txnid = 0; env->me_txns->mti_numreaders = 0; } else { if (env->me_txns->mti_magic != MDB_MAGIC) { DPUTS("lock region has invalid magic"); rc = EINVAL; goto fail; } if (env->me_txns->mti_version != MDB_VERSION) { DPRINTF("lock region is version %u, expected version %u", env->me_txns->mti_version, MDB_VERSION); rc = MDB_VERSION_MISMATCH; goto fail; } rc = ErrCode(); if (rc != EACCES && rc != EAGAIN) { goto fail; } #ifdef _WIN32 env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname); if (!env->me_rmutex) { rc = ErrCode(); goto fail; } env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname); if (!env->me_wmutex) { rc = ErrCode(); goto fail; } #endif #ifdef USE_POSIX_SEM env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0); if (!env->me_rmutex) { rc = ErrCode(); goto fail; } env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0); if (!env->me_wmutex) { rc = ErrCode(); goto fail; } #endif } return MDB_SUCCESS; fail: close(env->me_lfd); env->me_lfd = INVALID_HANDLE_VALUE; return rc; } /** The name of the lock file in the DB environment */ #define LOCKNAME "/lock.mdb" /** The name of the data file in the DB environment */ #define DATANAME "/data.mdb" /** The suffix of the lock file when no subdir is used */ #define LOCKSUFF "-lock" int mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode) { int oflags, rc, len, excl; char *lpath, *dpath; len = strlen(path); if (flags & MDB_NOSUBDIR) { rc = len + sizeof(LOCKSUFF) + len + 1; } else { rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME); } lpath = malloc(rc); if (!lpath) return ENOMEM; if (flags & MDB_NOSUBDIR) { dpath = lpath + len + sizeof(LOCKSUFF); sprintf(lpath, "%s" LOCKSUFF, path); strcpy(dpath, path); } else { dpath = lpath + len + sizeof(LOCKNAME); sprintf(lpath, "%s" LOCKNAME, path); sprintf(dpath, "%s" DATANAME, path); } rc = mdb_env_setup_locks(env, lpath, mode, &excl); if (rc) goto leave; #ifdef _WIN32 if (F_ISSET(flags, MDB_RDONLY)) { oflags = GENERIC_READ; len = OPEN_EXISTING; } else { oflags = GENERIC_READ|GENERIC_WRITE; len = OPEN_ALWAYS; } mode = FILE_ATTRIBUTE_NORMAL; env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len, mode, NULL); #else if (F_ISSET(flags, MDB_RDONLY)) oflags = O_RDONLY; else oflags = O_RDWR | O_CREAT; env->me_fd = open(dpath, oflags, mode); #endif if (env->me_fd == INVALID_HANDLE_VALUE) { rc = ErrCode(); goto leave; } if ((rc = mdb_env_open2(env, flags)) == MDB_SUCCESS) { if (flags & (MDB_RDONLY|MDB_NOSYNC|MDB_NOMETASYNC)) { env->me_mfd = env->me_fd; } else { /* synchronous fd for meta writes */ #ifdef _WIN32 env->me_mfd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len, mode | FILE_FLAG_WRITE_THROUGH, NULL); #else env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode); #endif if (env->me_mfd == INVALID_HANDLE_VALUE) { rc = ErrCode(); goto leave; } } env->me_path = strdup(path); DPRINTF("opened dbenv %p", (void *) env); pthread_key_create(&env->me_txkey, mdb_env_reader_dest); #ifdef _WIN32 /* Windows TLS callbacks need help finding their TLS info. */ if (mdb_tls_nkeys < MAX_TLS_KEYS) mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey; else { rc = ENOMEM; goto leave; } #endif if (excl) mdb_env_share_locks(env); env->me_numdbs = 2; env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx)); env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t)); if (!env->me_dbxs || !env->me_dbflags) rc = ENOMEM; } leave: if (rc) { if (env->me_fd != INVALID_HANDLE_VALUE) { close(env->me_fd); env->me_fd = INVALID_HANDLE_VALUE; } if (env->me_lfd != INVALID_HANDLE_VALUE) { close(env->me_lfd); env->me_lfd = INVALID_HANDLE_VALUE; } } free(lpath); return rc; } void mdb_env_close(MDB_env *env) { MDB_page *dp; if (env == NULL) return; VGMEMP_DESTROY(env); while (env->me_dpages) { dp = env->me_dpages; VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next)); env->me_dpages = dp->mp_next; free(dp); } free(env->me_dbflags); free(env->me_dbxs); free(env->me_path); pthread_key_delete(env->me_txkey); #ifdef _WIN32 /* Delete our key from the global list */ { int i; for (i=0; ime_txkey) { mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1]; mdb_tls_nkeys--; break; } } #endif if (env->me_map) { munmap(env->me_map, env->me_mapsize); } if (env->me_mfd != env->me_fd) close(env->me_mfd); close(env->me_fd); if (env->me_txns) { pid_t pid = getpid(); unsigned int i; for (i=0; ime_txns->mti_numreaders; i++) if (env->me_txns->mti_readers[i].mr_pid == pid) env->me_txns->mti_readers[i].mr_pid = 0; munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo)); } close(env->me_lfd); mdb_midl_free(env->me_free_pgs); free(env); } /** Compare two items pointing at aligned size_t's */ static int mdb_cmp_long(const MDB_val *a, const MDB_val *b) { return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 : *(size_t *)a->mv_data > *(size_t *)b->mv_data; } /** Compare two items pointing at aligned int's */ static int mdb_cmp_int(const MDB_val *a, const MDB_val *b) { return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 : *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data; } /** Compare two items pointing at ints of unknown alignment. * Nodes and keys are guaranteed to be 2-byte aligned. */ static int mdb_cmp_cint(const MDB_val *a, const MDB_val *b) { #if BYTE_ORDER == LITTLE_ENDIAN unsigned short *u, *c; int x; u = (unsigned short *) ((char *) a->mv_data + a->mv_size); c = (unsigned short *) ((char *) b->mv_data + a->mv_size); do { x = *--u - *--c; } while(!x && u > (unsigned short *)a->mv_data); return x; #else return memcmp(a->mv_data, b->mv_data, a->mv_size); #endif } /** Compare two items lexically */ static int mdb_cmp_memn(const MDB_val *a, const MDB_val *b) { int diff; ssize_t len_diff; unsigned int len; len = a->mv_size; len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size; if (len_diff > 0) { len = b->mv_size; len_diff = 1; } diff = memcmp(a->mv_data, b->mv_data, len); return diff ? diff : len_diff<0 ? -1 : len_diff; } /** Compare two items in reverse byte order */ static int mdb_cmp_memnr(const MDB_val *a, const MDB_val *b) { const unsigned char *p1, *p2, *p1_lim; ssize_t len_diff; int diff; p1_lim = (const unsigned char *)a->mv_data; p1 = (const unsigned char *)a->mv_data + a->mv_size; p2 = (const unsigned char *)b->mv_data + b->mv_size; len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size; if (len_diff > 0) { p1_lim += len_diff; len_diff = 1; } while (p1 > p1_lim) { diff = *--p1 - *--p2; if (diff) return diff; } return len_diff<0 ? -1 : len_diff; } /** Search for key within a page, using binary search. * Returns the smallest entry larger or equal to the key. * If exactp is non-null, stores whether the found entry was an exact match * in *exactp (1 or 0). * Updates the cursor index with the index of the found entry. * If no entry larger or equal to the key is found, returns NULL. */ static MDB_node * mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp) { unsigned int i = 0, nkeys; int low, high; int rc = 0; MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_node *node = NULL; MDB_val nodekey; MDB_cmp_func *cmp; DKBUF; nkeys = NUMKEYS(mp); #if MDB_DEBUG { pgno_t pgno; COPY_PGNO(pgno, mp->mp_pgno); DPRINTF("searching %u keys in %s %spage %zu", nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "", pgno); } #endif assert(nkeys > 0); low = IS_LEAF(mp) ? 0 : 1; high = nkeys - 1; cmp = mc->mc_dbx->md_cmp; /* Branch pages have no data, so if using integer keys, * alignment is guaranteed. Use faster mdb_cmp_int. */ if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) { if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t)) cmp = mdb_cmp_long; else cmp = mdb_cmp_int; } if (IS_LEAF2(mp)) { nodekey.mv_size = mc->mc_db->md_pad; node = NODEPTR(mp, 0); /* fake */ while (low <= high) { i = (low + high) >> 1; nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size); rc = cmp(key, &nodekey); DPRINTF("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc); if (rc == 0) break; if (rc > 0) low = i + 1; else high = i - 1; } } else { while (low <= high) { i = (low + high) >> 1; node = NODEPTR(mp, i); nodekey.mv_size = NODEKSZ(node); nodekey.mv_data = NODEKEY(node); rc = cmp(key, &nodekey); #if MDB_DEBUG if (IS_LEAF(mp)) DPRINTF("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc); else DPRINTF("found branch index %u [%s -> %zu], rc = %i", i, DKEY(&nodekey), NODEPGNO(node), rc); #endif if (rc == 0) break; if (rc > 0) low = i + 1; else high = i - 1; } } if (rc > 0) { /* Found entry is less than the key. */ i++; /* Skip to get the smallest entry larger than key. */ if (!IS_LEAF2(mp)) node = NODEPTR(mp, i); } if (exactp) *exactp = (rc == 0); /* store the key index */ mc->mc_ki[mc->mc_top] = i; if (i >= nkeys) /* There is no entry larger or equal to the key. */ return NULL; /* nodeptr is fake for LEAF2 */ return node; } #if 0 static void mdb_cursor_adjust(MDB_cursor *mc, func) { MDB_cursor *m2; for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) { func(mc, m2); } } } #endif /** Pop a page off the top of the cursor's stack. */ static void mdb_cursor_pop(MDB_cursor *mc) { if (mc->mc_snum) { #if MDB_DEBUG MDB_page *top = mc->mc_pg[mc->mc_top]; #endif mc->mc_snum--; if (mc->mc_snum) mc->mc_top--; DPRINTF("popped page %zu off db %u cursor %p", top->mp_pgno, mc->mc_dbi, (void *) mc); } } /** Push a page onto the top of the cursor's stack. */ static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp) { DPRINTF("pushing page %zu on db %u cursor %p", mp->mp_pgno, mc->mc_dbi, (void *) mc); if (mc->mc_snum >= CURSOR_STACK) { assert(mc->mc_snum < CURSOR_STACK); return ENOMEM; } mc->mc_top = mc->mc_snum++; mc->mc_pg[mc->mc_top] = mp; mc->mc_ki[mc->mc_top] = 0; return MDB_SUCCESS; } /** Find the address of the page corresponding to a given page number. * @param[in] txn the transaction for this access. * @param[in] pgno the page number for the page to retrieve. * @param[out] ret address of a pointer where the page's address will be stored. * @return 0 on success, non-zero on failure. */ static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret) { MDB_page *p = NULL; if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) { unsigned x; x = mdb_mid2l_search(txn->mt_u.dirty_list, pgno); if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) { p = txn->mt_u.dirty_list[x].mptr; } } if (!p) { if (pgno < txn->mt_next_pgno) p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno); } *ret = p; if (!p) { DPRINTF("page %zu not found", pgno); assert(p != NULL); } return (p != NULL) ? MDB_SUCCESS : MDB_PAGE_NOTFOUND; } /** Search for the page a given key should be in. * Pushes parent pages on the cursor stack. This function continues a * search on a cursor that has already been initialized. (Usually by * #mdb_page_search() but also by #mdb_node_move().) * @param[in,out] mc the cursor for this operation. * @param[in] key the key to search for. If NULL, search for the lowest * page. (This is used by #mdb_cursor_first().) * @param[in] flags If MDB_PS_MODIFY set, visited pages are updated with new page numbers. * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups. * @return 0 on success, non-zero on failure. */ static int mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify) { MDB_page *mp = mc->mc_pg[mc->mc_top]; DKBUF; int rc; while (IS_BRANCH(mp)) { MDB_node *node; indx_t i; DPRINTF("branch page %zu has %u keys", mp->mp_pgno, NUMKEYS(mp)); assert(NUMKEYS(mp) > 1); DPRINTF("found index 0 to page %zu", NODEPGNO(NODEPTR(mp, 0))); if (key == NULL) /* Initialize cursor to first page. */ i = 0; else if (key->mv_size > MAXKEYSIZE && key->mv_data == NULL) { /* cursor to last page */ i = NUMKEYS(mp)-1; } else { int exact; node = mdb_node_search(mc, key, &exact); if (node == NULL) i = NUMKEYS(mp) - 1; else { i = mc->mc_ki[mc->mc_top]; if (!exact) { assert(i > 0); i--; } } } if (key) DPRINTF("following index %u for key [%s]", i, DKEY(key)); assert(i < NUMKEYS(mp)); node = NODEPTR(mp, i); if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp))) return rc; mc->mc_ki[mc->mc_top] = i; if ((rc = mdb_cursor_push(mc, mp))) return rc; if (modify) { if ((rc = mdb_page_touch(mc)) != 0) return rc; mp = mc->mc_pg[mc->mc_top]; } } if (!IS_LEAF(mp)) { DPRINTF("internal error, index points to a %02X page!?", mp->mp_flags); return MDB_CORRUPTED; } DPRINTF("found leaf page %zu for key [%s]", mp->mp_pgno, key ? DKEY(key) : NULL); return MDB_SUCCESS; } /** Search for the page a given key should be in. * Pushes parent pages on the cursor stack. This function just sets up * the search; it finds the root page for \b mc's database and sets this * as the root of the cursor's stack. Then #mdb_page_search_root() is * called to complete the search. * @param[in,out] mc the cursor for this operation. * @param[in] key the key to search for. If NULL, search for the lowest * page. (This is used by #mdb_cursor_first().) * @param[in] modify If true, visited pages are updated with new page numbers. * @return 0 on success, non-zero on failure. */ static int mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags) { int rc; pgno_t root; /* Make sure the txn is still viable, then find the root from * the txn's db table. */ if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) { DPUTS("transaction has failed, must abort"); return EINVAL; } else { /* Make sure we're using an up-to-date root */ if (mc->mc_dbi > MAIN_DBI) { if ((*mc->mc_dbflag & DB_STALE) || ((flags & MDB_PS_MODIFY) && !(*mc->mc_dbflag & DB_DIRTY))) { MDB_cursor mc2; unsigned char dbflag = 0; mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL); rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, flags & MDB_PS_MODIFY); if (rc) return rc; if (*mc->mc_dbflag & DB_STALE) { MDB_val data; int exact = 0; MDB_node *leaf = mdb_node_search(&mc2, &mc->mc_dbx->md_name, &exact); if (!exact) return MDB_NOTFOUND; mdb_node_read(mc->mc_txn, leaf, &data); memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db)); } if (flags & MDB_PS_MODIFY) dbflag = DB_DIRTY; *mc->mc_dbflag = dbflag; } } root = mc->mc_db->md_root; if (root == P_INVALID) { /* Tree is empty. */ DPUTS("tree is empty"); return MDB_NOTFOUND; } } assert(root > 1); if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0]))) return rc; mc->mc_snum = 1; mc->mc_top = 0; DPRINTF("db %u root page %zu has flags 0x%X", mc->mc_dbi, root, mc->mc_pg[0]->mp_flags); if (flags & MDB_PS_MODIFY) { if ((rc = mdb_page_touch(mc))) return rc; } if (flags & MDB_PS_ROOTONLY) return MDB_SUCCESS; return mdb_page_search_root(mc, key, flags); } /** Return the data associated with a given node. * @param[in] txn The transaction for this operation. * @param[in] leaf The node being read. * @param[out] data Updated to point to the node's data. * @return 0 on success, non-zero on failure. */ static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data) { MDB_page *omp; /* overflow page */ pgno_t pgno; int rc; if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) { data->mv_size = NODEDSZ(leaf); data->mv_data = NODEDATA(leaf); return MDB_SUCCESS; } /* Read overflow data. */ data->mv_size = NODEDSZ(leaf); memcpy(&pgno, NODEDATA(leaf), sizeof(pgno)); if ((rc = mdb_page_get(txn, pgno, &omp))) { DPRINTF("read overflow page %zu failed", pgno); return rc; } data->mv_data = METADATA(omp); return MDB_SUCCESS; } int mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) { MDB_cursor mc; MDB_xcursor mx; int exact = 0; DKBUF; assert(key); assert(data); DPRINTF("===> get db %u key [%s]", dbi, DKEY(key)); if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) return EINVAL; if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { return EINVAL; } mdb_cursor_init(&mc, txn, dbi, &mx); return mdb_cursor_set(&mc, key, data, MDB_SET, &exact); } /** Find a sibling for a page. * Replaces the page at the top of the cursor's stack with the * specified sibling, if one exists. * @param[in] mc The cursor for this operation. * @param[in] move_right Non-zero if the right sibling is requested, * otherwise the left sibling. * @return 0 on success, non-zero on failure. */ static int mdb_cursor_sibling(MDB_cursor *mc, int move_right) { int rc; MDB_node *indx; MDB_page *mp; if (mc->mc_snum < 2) { return MDB_NOTFOUND; /* root has no siblings */ } mdb_cursor_pop(mc); DPRINTF("parent page is page %zu, index %u", mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]); if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top])) : (mc->mc_ki[mc->mc_top] == 0)) { DPRINTF("no more keys left, moving to %s sibling", move_right ? "right" : "left"); if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) return rc; } else { if (move_right) mc->mc_ki[mc->mc_top]++; else mc->mc_ki[mc->mc_top]--; DPRINTF("just moving to %s index key %u", move_right ? "right" : "left", mc->mc_ki[mc->mc_top]); } assert(IS_BRANCH(mc->mc_pg[mc->mc_top])); indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp))) return rc;; mdb_cursor_push(mc, mp); return MDB_SUCCESS; } /** Move the cursor to the next data item. */ static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { MDB_page *mp; MDB_node *leaf; int rc; if (mc->mc_flags & C_EOF) { return MDB_NOTFOUND; } assert(mc->mc_flags & C_INITIALIZED); mp = mc->mc_pg[mc->mc_top]; if (mc->mc_db->md_flags & MDB_DUPSORT) { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_NEXT || op == MDB_NEXT_DUP) { rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT); if (op != MDB_NEXT || rc == MDB_SUCCESS) return rc; } } else { mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; if (op == MDB_NEXT_DUP) return MDB_NOTFOUND; } } DPRINTF("cursor_next: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc); if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) { DPUTS("=====> move to next sibling page"); if (mdb_cursor_sibling(mc, 1) != MDB_SUCCESS) { mc->mc_flags |= C_EOF; mc->mc_flags &= ~C_INITIALIZED; return MDB_NOTFOUND; } mp = mc->mc_pg[mc->mc_top]; DPRINTF("next page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]); } else mc->mc_ki[mc->mc_top]++; DPRINTF("==> cursor points to page %zu with %u keys, key index %u", mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]); if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } assert(IS_LEAF(mp)); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); } if (data) { if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS)) return rc; if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc != MDB_SUCCESS) return rc; } } MDB_SET_KEY(leaf, key); return MDB_SUCCESS; } /** Move the cursor to the previous data item. */ static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { MDB_page *mp; MDB_node *leaf; int rc; assert(mc->mc_flags & C_INITIALIZED); mp = mc->mc_pg[mc->mc_top]; if (mc->mc_db->md_flags & MDB_DUPSORT) { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (op == MDB_PREV || op == MDB_PREV_DUP) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV); if (op != MDB_PREV || rc == MDB_SUCCESS) return rc; } else { mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; if (op == MDB_PREV_DUP) return MDB_NOTFOUND; } } } DPRINTF("cursor_prev: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc); if (mc->mc_ki[mc->mc_top] == 0) { DPUTS("=====> move to prev sibling page"); if (mdb_cursor_sibling(mc, 0) != MDB_SUCCESS) { mc->mc_flags &= ~C_INITIALIZED; return MDB_NOTFOUND; } mp = mc->mc_pg[mc->mc_top]; mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1; DPRINTF("prev page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]); } else mc->mc_ki[mc->mc_top]--; mc->mc_flags &= ~C_EOF; DPRINTF("==> cursor points to page %zu with %u keys, key index %u", mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]); if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } assert(IS_LEAF(mp)); leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); } if (data) { if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS)) return rc; if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc != MDB_SUCCESS) return rc; } } MDB_SET_KEY(leaf, key); return MDB_SUCCESS; } /** Set the cursor on a specific data item. */ static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op, int *exactp) { int rc; MDB_page *mp; MDB_node *leaf = NULL; DKBUF; assert(mc); assert(key); assert(key->mv_size > 0); /* See if we're already on the right page */ if (mc->mc_flags & C_INITIALIZED) { MDB_val nodekey; mp = mc->mc_pg[mc->mc_top]; if (!NUMKEYS(mp)) { mc->mc_ki[mc->mc_top] = 0; return MDB_NOTFOUND; } if (mp->mp_flags & P_LEAF2) { nodekey.mv_size = mc->mc_db->md_pad; nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size); } else { leaf = NODEPTR(mp, 0); MDB_SET_KEY(leaf, &nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* Probably happens rarely, but first node on the page * was the one we wanted. */ mc->mc_ki[mc->mc_top] = 0; if (exactp) *exactp = 1; goto set1; } if (rc > 0) { unsigned int i; unsigned int nkeys = NUMKEYS(mp); if (nkeys > 1) { if (mp->mp_flags & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, nkeys-1, nodekey.mv_size); } else { leaf = NODEPTR(mp, nkeys-1); MDB_SET_KEY(leaf, &nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* last node was the one we wanted */ mc->mc_ki[mc->mc_top] = nkeys-1; if (exactp) *exactp = 1; goto set1; } if (rc < 0) { if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) { /* This is definitely the right page, skip search_page */ if (mp->mp_flags & P_LEAF2) { nodekey.mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], nodekey.mv_size); } else { leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); MDB_SET_KEY(leaf, &nodekey); } rc = mc->mc_dbx->md_cmp(key, &nodekey); if (rc == 0) { /* current node was the one we wanted */ if (exactp) *exactp = 1; goto set1; } } rc = 0; goto set2; } } /* If any parents have right-sibs, search. * Otherwise, there's nothing further. */ for (i=0; imc_top; i++) if (mc->mc_ki[i] < NUMKEYS(mc->mc_pg[i])-1) break; if (i == mc->mc_top) { /* There are no other pages */ mc->mc_ki[mc->mc_top] = nkeys; return MDB_NOTFOUND; } } if (!mc->mc_top) { /* There are no other pages */ mc->mc_ki[mc->mc_top] = 0; return MDB_NOTFOUND; } } rc = mdb_page_search(mc, key, 0); if (rc != MDB_SUCCESS) return rc; mp = mc->mc_pg[mc->mc_top]; assert(IS_LEAF(mp)); set2: leaf = mdb_node_search(mc, key, exactp); if (exactp != NULL && !*exactp) { /* MDB_SET specified and not an exact match. */ return MDB_NOTFOUND; } if (leaf == NULL) { DPUTS("===> inexact leaf not found, goto sibling"); if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) return rc; /* no entries matched */ mp = mc->mc_pg[mc->mc_top]; assert(IS_LEAF(mp)); leaf = NODEPTR(mp, 0); } set1: mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; if (IS_LEAF2(mp)) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); } if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (op == MDB_SET || op == MDB_SET_RANGE) { rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); } else { int ex2, *ex2p; if (op == MDB_GET_BOTH) { ex2p = &ex2; ex2 = 0; } else { ex2p = NULL; } rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p); if (rc != MDB_SUCCESS) return rc; } } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) { MDB_val d2; if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS) return rc; rc = mc->mc_dbx->md_dcmp(data, &d2); if (rc) { if (op == MDB_GET_BOTH || rc > 0) return MDB_NOTFOUND; } } else { if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; } } /* The key already matches in all other cases */ if (op == MDB_SET_RANGE) MDB_SET_KEY(leaf, key); DPRINTF("==> cursor placed on key [%s]", DKEY(key)); return rc; } /** Move the cursor to the first item in the database. */ static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data) { int rc; MDB_node *leaf; if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { rc = mdb_page_search(mc, NULL, 0); if (rc != MDB_SUCCESS) return rc; } assert(IS_LEAF(mc->mc_pg[mc->mc_top])); leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0); mc->mc_flags |= C_INITIALIZED; mc->mc_flags &= ~C_EOF; mc->mc_ki[mc->mc_top] = 0; if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size); return MDB_SUCCESS; } if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc) return rc; } else { if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; } } MDB_SET_KEY(leaf, key); return MDB_SUCCESS; } /** Move the cursor to the last item in the database. */ static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data) { int rc; MDB_node *leaf; if (!(mc->mc_flags & C_EOF)) { if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { MDB_val lkey; lkey.mv_size = MAXKEYSIZE+1; lkey.mv_data = NULL; rc = mdb_page_search(mc, &lkey, 0); if (rc != MDB_SUCCESS) return rc; } assert(IS_LEAF(mc->mc_pg[mc->mc_top])); mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1; mc->mc_flags |= C_INITIALIZED|C_EOF; } leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { key->mv_size = mc->mc_db->md_pad; key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size); return MDB_SUCCESS; } if (data) { if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { mdb_xcursor_init1(mc, leaf); rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); if (rc) return rc; } else { if (mc->mc_xcursor) mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) return rc; } } MDB_SET_KEY(leaf, key); return MDB_SUCCESS; } int mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) { int rc; int exact = 0; assert(mc); switch (op) { case MDB_GET_BOTH: case MDB_GET_BOTH_RANGE: if (data == NULL || mc->mc_xcursor == NULL) { rc = EINVAL; break; } /* FALLTHRU */ case MDB_SET: case MDB_SET_RANGE: if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { rc = EINVAL; } else if (op == MDB_SET_RANGE) rc = mdb_cursor_set(mc, key, data, op, NULL); else rc = mdb_cursor_set(mc, key, data, op, &exact); break; case MDB_GET_MULTIPLE: if (data == NULL || !(mc->mc_db->md_flags & MDB_DUPFIXED) || !(mc->mc_flags & C_INITIALIZED)) { rc = EINVAL; break; } rc = MDB_SUCCESS; if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) || (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF)) break; goto fetchm; case MDB_NEXT_MULTIPLE: if (data == NULL || !(mc->mc_db->md_flags & MDB_DUPFIXED)) { rc = EINVAL; break; } if (!(mc->mc_flags & C_INITIALIZED)) rc = mdb_cursor_first(mc, key, data); else rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP); if (rc == MDB_SUCCESS) { if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) { MDB_cursor *mx; fetchm: mx = &mc->mc_xcursor->mx_cursor; data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) * mx->mc_db->md_pad; data->mv_data = METADATA(mx->mc_pg[mx->mc_top]); mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1; } else { rc = MDB_NOTFOUND; } } break; case MDB_NEXT: case MDB_NEXT_DUP: case MDB_NEXT_NODUP: if (!(mc->mc_flags & C_INITIALIZED)) rc = mdb_cursor_first(mc, key, data); else rc = mdb_cursor_next(mc, key, data, op); break; case MDB_PREV: case MDB_PREV_DUP: case MDB_PREV_NODUP: if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF)) { rc = mdb_cursor_last(mc, key, data); mc->mc_flags &= ~C_EOF; } else rc = mdb_cursor_prev(mc, key, data, op); break; case MDB_FIRST: rc = mdb_cursor_first(mc, key, data); break; case MDB_FIRST_DUP: if (data == NULL || !(mc->mc_db->md_flags & MDB_DUPSORT) || !(mc->mc_flags & C_INITIALIZED) || !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) { rc = EINVAL; break; } rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); break; case MDB_LAST: rc = mdb_cursor_last(mc, key, data); break; case MDB_LAST_DUP: if (data == NULL || !(mc->mc_db->md_flags & MDB_DUPSORT) || !(mc->mc_flags & C_INITIALIZED) || !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) { rc = EINVAL; break; } rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); break; default: DPRINTF("unhandled/unimplemented cursor operation %u", op); rc = EINVAL; break; } return rc; } /** Touch all the pages in the cursor stack. * Makes sure all the pages are writable, before attempting a write operation. * @param[in] mc The cursor to operate on. */ static int mdb_cursor_touch(MDB_cursor *mc) { int rc; if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) { MDB_cursor mc2; mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL); rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY); if (rc) return rc; *mc->mc_dbflag = DB_DIRTY; } for (mc->mc_top = 0; mc->mc_top < mc->mc_snum; mc->mc_top++) { rc = mdb_page_touch(mc); if (rc) return rc; } mc->mc_top = mc->mc_snum-1; return MDB_SUCCESS; } int mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data, unsigned int flags) { MDB_node *leaf = NULL; MDB_val xdata, *rdata, dkey; MDB_page *fp; MDB_db dummy; int do_sub = 0, insert = 0; unsigned int mcount = 0; size_t nsize; int rc, rc2; MDB_pagebuf pbuf; char dbuf[MAXKEYSIZE+1]; unsigned int nflags; DKBUF; if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY)) return EACCES; DPRINTF("==> put db %u key [%s], size %zu, data size %zu", mc->mc_dbi, DKEY(key), key ? key->mv_size:0, data->mv_size); dkey.mv_size = 0; if (flags == MDB_CURRENT) { if (!(mc->mc_flags & C_INITIALIZED)) return EINVAL; rc = MDB_SUCCESS; } else if (mc->mc_db->md_root == P_INVALID) { MDB_page *np; /* new database, write a root leaf page */ DPUTS("allocating new root leaf page"); if ((np = mdb_page_new(mc, P_LEAF, 1)) == NULL) { return ENOMEM; } mc->mc_snum = 0; mdb_cursor_push(mc, np); mc->mc_db->md_root = np->mp_pgno; mc->mc_db->md_depth++; *mc->mc_dbflag = DB_DIRTY; if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED)) == MDB_DUPFIXED) np->mp_flags |= P_LEAF2; mc->mc_flags |= C_INITIALIZED; rc = MDB_NOTFOUND; goto top; } else { int exact = 0; MDB_val d2; if (flags & MDB_APPEND) { MDB_val k2; rc = mdb_cursor_last(mc, &k2, &d2); if (rc == 0) { rc = mc->mc_dbx->md_cmp(key, &k2); if (rc > 0) { rc = MDB_NOTFOUND; mc->mc_ki[mc->mc_top]++; } else { rc = 0; } } } else { rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact); } if ((flags & MDB_NOOVERWRITE) && rc == 0) { DPRINTF("duplicate key [%s]", DKEY(key)); *data = d2; return MDB_KEYEXIST; } if (rc && rc != MDB_NOTFOUND) return rc; } /* Cursor is positioned, now make sure all pages are writable */ rc2 = mdb_cursor_touch(mc); if (rc2) return rc2; top: /* The key already exists */ if (rc == MDB_SUCCESS) { /* there's only a key anyway, so this is a no-op */ if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { unsigned int ksize = mc->mc_db->md_pad; if (key->mv_size != ksize) return EINVAL; if (flags == MDB_CURRENT) { char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize); memcpy(ptr, key->mv_data, ksize); } return MDB_SUCCESS; } leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); /* DB has dups? */ if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) { /* Was a single item before, must convert now */ more: if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { /* Just overwrite the current item */ if (flags == MDB_CURRENT) goto current; dkey.mv_size = NODEDSZ(leaf); dkey.mv_data = NODEDATA(leaf); #if UINT_MAX < SIZE_MAX if (mc->mc_dbx->md_dcmp == mdb_cmp_int && dkey.mv_size == sizeof(size_t)) #ifdef MISALIGNED_OK mc->mc_dbx->md_dcmp = mdb_cmp_long; #else mc->mc_dbx->md_dcmp = mdb_cmp_cint; #endif #endif /* if data matches, ignore it */ if (!mc->mc_dbx->md_dcmp(data, &dkey)) return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS; /* create a fake page for the dup items */ memcpy(dbuf, dkey.mv_data, dkey.mv_size); dkey.mv_data = dbuf; fp = (MDB_page *)&pbuf; fp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno; fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP; fp->mp_lower = PAGEHDRSZ; fp->mp_upper = PAGEHDRSZ + dkey.mv_size + data->mv_size; if (mc->mc_db->md_flags & MDB_DUPFIXED) { fp->mp_flags |= P_LEAF2; fp->mp_pad = data->mv_size; fp->mp_upper += 2 * data->mv_size; /* leave space for 2 more */ } else { fp->mp_upper += 2 * sizeof(indx_t) + 2 * NODESIZE + (dkey.mv_size & 1) + (data->mv_size & 1); } mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0); do_sub = 1; rdata = &xdata; xdata.mv_size = fp->mp_upper; xdata.mv_data = fp; flags |= F_DUPDATA; goto new_sub; } if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) { /* See if we need to convert from fake page to subDB */ MDB_page *mp; unsigned int offset; unsigned int i; fp = NODEDATA(leaf); if (flags == MDB_CURRENT) { reuse: fp->mp_flags |= P_DIRTY; COPY_PGNO(fp->mp_pgno, mc->mc_pg[mc->mc_top]->mp_pgno); mc->mc_xcursor->mx_cursor.mc_pg[0] = fp; flags |= F_DUPDATA; goto put_sub; } if (mc->mc_db->md_flags & MDB_DUPFIXED) { offset = fp->mp_pad; if (SIZELEFT(fp) >= offset) goto reuse; offset *= 4; /* space for 4 more */ } else { offset = NODESIZE + sizeof(indx_t) + data->mv_size; } offset += offset & 1; if (NODESIZE + sizeof(indx_t) + NODEKSZ(leaf) + NODEDSZ(leaf) + offset >= (mc->mc_txn->mt_env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) { /* yes, convert it */ dummy.md_flags = 0; if (mc->mc_db->md_flags & MDB_DUPFIXED) { dummy.md_pad = fp->mp_pad; dummy.md_flags = MDB_DUPFIXED; if (mc->mc_db->md_flags & MDB_INTEGERDUP) dummy.md_flags |= MDB_INTEGERKEY; } dummy.md_depth = 1; dummy.md_branch_pages = 0; dummy.md_leaf_pages = 1; dummy.md_overflow_pages = 0; dummy.md_entries = NUMKEYS(fp); rdata = &xdata; xdata.mv_size = sizeof(MDB_db); xdata.mv_data = &dummy; mp = mdb_page_alloc(mc, 1); if (!mp) return ENOMEM; offset = mc->mc_txn->mt_env->me_psize - NODEDSZ(leaf); flags |= F_DUPDATA|F_SUBDATA; dummy.md_root = mp->mp_pgno; } else { /* no, just grow it */ rdata = &xdata; xdata.mv_size = NODEDSZ(leaf) + offset; xdata.mv_data = &pbuf; mp = (MDB_page *)&pbuf; mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno; flags |= F_DUPDATA; } mp->mp_flags = fp->mp_flags | P_DIRTY; mp->mp_pad = fp->mp_pad; mp->mp_lower = fp->mp_lower; mp->mp_upper = fp->mp_upper + offset; if (IS_LEAF2(fp)) { memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad); } else { nsize = NODEDSZ(leaf) - fp->mp_upper; memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper, nsize); for (i=0; imp_ptrs[i] = fp->mp_ptrs[i] + offset; } mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0); do_sub = 1; goto new_sub; } /* data is on sub-DB, just store it */ flags |= F_DUPDATA|F_SUBDATA; goto put_sub; } current: /* overflow page overwrites need special handling */ if (F_ISSET(leaf->mn_flags, F_BIGDATA)) { MDB_page *omp; pgno_t pg; int ovpages, dpages; ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize); dpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize); memcpy(&pg, NODEDATA(leaf), sizeof(pg)); mdb_page_get(mc->mc_txn, pg, &omp); /* Is the ov page writable and large enough? */ if ((omp->mp_flags & P_DIRTY) && ovpages >= dpages) { /* yes, overwrite it. Note in this case we don't * bother to try shrinking the node if the new data * is smaller than the overflow threshold. */ if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = METADATA(omp); else memcpy(METADATA(omp), data->mv_data, data->mv_size); goto done; } else { /* no, free ovpages */ int i; mc->mc_db->md_overflow_pages -= ovpages; for (i=0; imc_txn->mt_free_pgs, pg); pg++; } } } else if (NODEDSZ(leaf) == data->mv_size) { /* same size, just replace it. Note that we could * also reuse this node if the new data is smaller, * but instead we opt to shrink the node in that case. */ if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = NODEDATA(leaf); else memcpy(NODEDATA(leaf), data->mv_data, data->mv_size); goto done; } mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0); mc->mc_db->md_entries--; } else { DPRINTF("inserting key at index %i", mc->mc_ki[mc->mc_top]); insert = 1; } rdata = data; new_sub: nflags = flags & NODE_ADD_FLAGS; nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(mc->mc_txn->mt_env, key, rdata); if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) { if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA ) nflags &= ~MDB_APPEND; if (!insert) nflags |= MDB_SPLIT_REPLACE; rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags); } else { /* There is room already in this leaf page. */ rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags); if (rc == 0 && !do_sub && insert) { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; unsigned i = mc->mc_top; MDB_page *mp = mc->mc_pg[i]; if (mc->mc_flags & C_SUB) dbi--; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == mc || m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) { m3->mc_ki[i]++; } } } } if (rc != MDB_SUCCESS) mc->mc_txn->mt_flags |= MDB_TXN_ERROR; else { /* Now store the actual data in the child DB. Note that we're * storing the user data in the keys field, so there are strict * size limits on dupdata. The actual data fields of the child * DB are all zero size. */ if (do_sub) { int xflags; put_sub: xdata.mv_size = 0; xdata.mv_data = ""; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (flags & MDB_CURRENT) { xflags = MDB_CURRENT; } else { mdb_xcursor_init1(mc, leaf); xflags = (flags & MDB_NODUPDATA) ? MDB_NOOVERWRITE : 0; } /* converted, write the original data first */ if (dkey.mv_size) { rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags); if (rc) return rc; { /* Adjust other cursors pointing to mp */ MDB_cursor *m2; unsigned i = mc->mc_top; MDB_page *mp = mc->mc_pg[i]; for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) { mdb_xcursor_init1(m2, leaf); } } } } if (flags & MDB_APPENDDUP) xflags |= MDB_APPEND; rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags); if (flags & F_SUBDATA) { void *db = NODEDATA(leaf); memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); } } /* sub-writes might have failed so check rc again. * Don't increment count if we just replaced an existing item. */ if (!rc && !(flags & MDB_CURRENT)) mc->mc_db->md_entries++; if (flags & MDB_MULTIPLE) { mcount++; if (mcount < data[1].mv_size) { data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); goto more; } } } done: return rc; } int mdb_cursor_del(MDB_cursor *mc, unsigned int flags) { MDB_node *leaf; int rc; if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY)) return EACCES; if (!mc->mc_flags & C_INITIALIZED) return EINVAL; rc = mdb_cursor_touch(mc); if (rc) return rc; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_DUPDATA)) { if (flags != MDB_NODUPDATA) { if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) { mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); } rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, 0); /* If sub-DB still has entries, we're done */ if (mc->mc_xcursor->mx_db.md_entries) { if (leaf->mn_flags & F_SUBDATA) { /* update subDB info */ void *db = NODEDATA(leaf); memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); } else { /* shrink fake page */ mdb_node_shrink(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); } mc->mc_db->md_entries--; return rc; } /* otherwise fall thru and delete the sub-DB */ } if (leaf->mn_flags & F_SUBDATA) { /* add all the child DB's pages to the free list */ rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0); if (rc == MDB_SUCCESS) { mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries; } } } return mdb_cursor_del0(mc, leaf); } /** Allocate and initialize new pages for a database. * @param[in] mc a cursor on the database being added to. * @param[in] flags flags defining what type of page is being allocated. * @param[in] num the number of pages to allocate. This is usually 1, * unless allocating overflow pages for a large record. * @return Address of a page, or NULL on failure. */ static MDB_page * mdb_page_new(MDB_cursor *mc, uint32_t flags, int num) { MDB_page *np; if ((np = mdb_page_alloc(mc, num)) == NULL) return NULL; DPRINTF("allocated new mpage %zu, page size %u", np->mp_pgno, mc->mc_txn->mt_env->me_psize); np->mp_flags = flags | P_DIRTY; np->mp_lower = PAGEHDRSZ; np->mp_upper = mc->mc_txn->mt_env->me_psize; if (IS_BRANCH(np)) mc->mc_db->md_branch_pages++; else if (IS_LEAF(np)) mc->mc_db->md_leaf_pages++; else if (IS_OVERFLOW(np)) { mc->mc_db->md_overflow_pages += num; np->mp_pages = num; } return np; } /** Calculate the size of a leaf node. * The size depends on the environment's page size; if a data item * is too large it will be put onto an overflow page and the node * size will only include the key and not the data. Sizes are always * rounded up to an even number of bytes, to guarantee 2-byte alignment * of the #MDB_node headers. * @param[in] env The environment handle. * @param[in] key The key for the node. * @param[in] data The data for the node. * @return The number of bytes needed to store the node. */ static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data) { size_t sz; sz = LEAFSIZE(key, data); if (sz >= env->me_psize / MDB_MINKEYS) { /* put on overflow page */ sz -= data->mv_size - sizeof(pgno_t); } sz += sz & 1; return sz + sizeof(indx_t); } /** Calculate the size of a branch node. * The size should depend on the environment's page size but since * we currently don't support spilling large keys onto overflow * pages, it's simply the size of the #MDB_node header plus the * size of the key. Sizes are always rounded up to an even number * of bytes, to guarantee 2-byte alignment of the #MDB_node headers. * @param[in] env The environment handle. * @param[in] key The key for the node. * @return The number of bytes needed to store the node. */ static size_t mdb_branch_size(MDB_env *env, MDB_val *key) { size_t sz; sz = INDXSIZE(key); if (sz >= env->me_psize / MDB_MINKEYS) { /* put on overflow page */ /* not implemented */ /* sz -= key->size - sizeof(pgno_t); */ } return sz + sizeof(indx_t); } /** Add a node to the page pointed to by the cursor. * @param[in] mc The cursor for this operation. * @param[in] indx The index on the page where the new node should be added. * @param[in] key The key for the new node. * @param[in] data The data for the new node, if any. * @param[in] pgno The page number, if adding a branch node. * @param[in] flags Flags for the node. * @return 0 on success, non-zero on failure. Possible errors are: *
    *
  • ENOMEM - failed to allocate overflow pages for the node. *
  • ENOSPC - there is insufficient room in the page. This error * should never happen since all callers already calculate the * page's free space before calling this function. *
*/ static int mdb_node_add(MDB_cursor *mc, indx_t indx, MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags) { unsigned int i; size_t node_size = NODESIZE; indx_t ofs; MDB_node *node; MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_page *ofp = NULL; /* overflow page */ DKBUF; assert(mp->mp_upper >= mp->mp_lower); DPRINTF("add to %s %spage %zu index %i, data size %zu key size %zu [%s]", IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "", mp->mp_pgno, indx, data ? data->mv_size : 0, key ? key->mv_size : 0, key ? DKEY(key) : NULL); if (IS_LEAF2(mp)) { /* Move higher keys up one slot. */ int ksize = mc->mc_db->md_pad, dif; char *ptr = LEAF2KEY(mp, indx, ksize); dif = NUMKEYS(mp) - indx; if (dif > 0) memmove(ptr+ksize, ptr, dif*ksize); /* insert new key */ memcpy(ptr, key->mv_data, ksize); /* Just using these for counting */ mp->mp_lower += sizeof(indx_t); mp->mp_upper -= ksize - sizeof(indx_t); return MDB_SUCCESS; } if (key != NULL) node_size += key->mv_size; if (IS_LEAF(mp)) { assert(data); if (F_ISSET(flags, F_BIGDATA)) { /* Data already on overflow page. */ node_size += sizeof(pgno_t); } else if (node_size + data->mv_size >= mc->mc_txn->mt_env->me_psize / MDB_MINKEYS) { int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize); /* Put data on overflow page. */ DPRINTF("data size is %zu, node would be %zu, put data on overflow page", data->mv_size, node_size+data->mv_size); node_size += sizeof(pgno_t); if ((ofp = mdb_page_new(mc, P_OVERFLOW, ovpages)) == NULL) return ENOMEM; DPRINTF("allocated overflow page %zu", ofp->mp_pgno); flags |= F_BIGDATA; } else { node_size += data->mv_size; } } node_size += node_size & 1; if (node_size + sizeof(indx_t) > SIZELEFT(mp)) { DPRINTF("not enough room in page %zu, got %u ptrs", mp->mp_pgno, NUMKEYS(mp)); DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower, mp->mp_upper - mp->mp_lower); DPRINTF("node size = %zu", node_size); return ENOSPC; } /* Move higher pointers up one slot. */ for (i = NUMKEYS(mp); i > indx; i--) mp->mp_ptrs[i] = mp->mp_ptrs[i - 1]; /* Adjust free space offsets. */ ofs = mp->mp_upper - node_size; assert(ofs >= mp->mp_lower + sizeof(indx_t)); mp->mp_ptrs[indx] = ofs; mp->mp_upper = ofs; mp->mp_lower += sizeof(indx_t); /* Write the node data. */ node = NODEPTR(mp, indx); node->mn_ksize = (key == NULL) ? 0 : key->mv_size; node->mn_flags = flags; if (IS_LEAF(mp)) SETDSZ(node,data->mv_size); else SETPGNO(node,pgno); if (key) memcpy(NODEKEY(node), key->mv_data, key->mv_size); if (IS_LEAF(mp)) { assert(key); if (ofp == NULL) { if (F_ISSET(flags, F_BIGDATA)) memcpy(node->mn_data + key->mv_size, data->mv_data, sizeof(pgno_t)); else if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = node->mn_data + key->mv_size; else memcpy(node->mn_data + key->mv_size, data->mv_data, data->mv_size); } else { memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno, sizeof(pgno_t)); if (F_ISSET(flags, MDB_RESERVE)) data->mv_data = METADATA(ofp); else memcpy(METADATA(ofp), data->mv_data, data->mv_size); } } return MDB_SUCCESS; } /** Delete the specified node from a page. * @param[in] mp The page to operate on. * @param[in] indx The index of the node to delete. * @param[in] ksize The size of a node. Only used if the page is * part of a #MDB_DUPFIXED database. */ static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize) { unsigned int sz; indx_t i, j, numkeys, ptr; MDB_node *node; char *base; #if MDB_DEBUG { pgno_t pgno; COPY_PGNO(pgno, mp->mp_pgno); DPRINTF("delete node %u on %s page %zu", indx, IS_LEAF(mp) ? "leaf" : "branch", pgno); } #endif assert(indx < NUMKEYS(mp)); if (IS_LEAF2(mp)) { int x = NUMKEYS(mp) - 1 - indx; base = LEAF2KEY(mp, indx, ksize); if (x) memmove(base, base + ksize, x * ksize); mp->mp_lower -= sizeof(indx_t); mp->mp_upper += ksize - sizeof(indx_t); return; } node = NODEPTR(mp, indx); sz = NODESIZE + node->mn_ksize; if (IS_LEAF(mp)) { if (F_ISSET(node->mn_flags, F_BIGDATA)) sz += sizeof(pgno_t); else sz += NODEDSZ(node); } sz += sz & 1; ptr = mp->mp_ptrs[indx]; numkeys = NUMKEYS(mp); for (i = j = 0; i < numkeys; i++) { if (i != indx) { mp->mp_ptrs[j] = mp->mp_ptrs[i]; if (mp->mp_ptrs[i] < ptr) mp->mp_ptrs[j] += sz; j++; } } base = (char *)mp + mp->mp_upper; memmove(base + sz, base, ptr - mp->mp_upper); mp->mp_lower -= sizeof(indx_t); mp->mp_upper += sz; } /** Compact the main page after deleting a node on a subpage. * @param[in] mp The main page to operate on. * @param[in] indx The index of the subpage on the main page. */ static void mdb_node_shrink(MDB_page *mp, indx_t indx) { MDB_node *node; MDB_page *sp, *xp; char *base; int osize, nsize; int delta; indx_t i, numkeys, ptr; node = NODEPTR(mp, indx); sp = (MDB_page *)NODEDATA(node); osize = NODEDSZ(node); delta = sp->mp_upper - sp->mp_lower; SETDSZ(node, osize - delta); xp = (MDB_page *)((char *)sp + delta); /* shift subpage upward */ if (IS_LEAF2(sp)) { nsize = NUMKEYS(sp) * sp->mp_pad; memmove(METADATA(xp), METADATA(sp), nsize); } else { int i; nsize = osize - sp->mp_upper; numkeys = NUMKEYS(sp); for (i=numkeys-1; i>=0; i--) xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta; } xp->mp_upper = sp->mp_lower; xp->mp_lower = sp->mp_lower; xp->mp_flags = sp->mp_flags; xp->mp_pad = sp->mp_pad; COPY_PGNO(xp->mp_pgno, mp->mp_pgno); /* shift lower nodes upward */ ptr = mp->mp_ptrs[indx]; numkeys = NUMKEYS(mp); for (i = 0; i < numkeys; i++) { if (mp->mp_ptrs[i] <= ptr) mp->mp_ptrs[i] += delta; } base = (char *)mp + mp->mp_upper; memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node)); mp->mp_upper += delta; } /** Initial setup of a sorted-dups cursor. * Sorted duplicates are implemented as a sub-database for the given key. * The duplicate data items are actually keys of the sub-database. * Operations on the duplicate data items are performed using a sub-cursor * initialized when the sub-database is first accessed. This function does * the preliminary setup of the sub-cursor, filling in the fields that * depend only on the parent DB. * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. */ static void mdb_xcursor_init0(MDB_cursor *mc) { MDB_xcursor *mx = mc->mc_xcursor; mx->mx_cursor.mc_xcursor = NULL; mx->mx_cursor.mc_txn = mc->mc_txn; mx->mx_cursor.mc_db = &mx->mx_db; mx->mx_cursor.mc_dbx = &mx->mx_dbx; mx->mx_cursor.mc_dbi = mc->mc_dbi+1; mx->mx_cursor.mc_dbflag = &mx->mx_dbflag; mx->mx_cursor.mc_snum = 0; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_flags = C_SUB; mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp; mx->mx_dbx.md_dcmp = NULL; mx->mx_dbx.md_rel = mc->mc_dbx->md_rel; } /** Final setup of a sorted-dups cursor. * Sets up the fields that depend on the data from the main cursor. * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. * @param[in] node The data containing the #MDB_db record for the * sorted-dup database. */ static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node) { MDB_xcursor *mx = mc->mc_xcursor; if (node->mn_flags & F_SUBDATA) { memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db)); mx->mx_cursor.mc_pg[0] = 0; mx->mx_cursor.mc_snum = 0; mx->mx_cursor.mc_flags = C_SUB; } else { MDB_page *fp = NODEDATA(node); mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad; mx->mx_db.md_flags = 0; mx->mx_db.md_depth = 1; mx->mx_db.md_branch_pages = 0; mx->mx_db.md_leaf_pages = 1; mx->mx_db.md_overflow_pages = 0; mx->mx_db.md_entries = NUMKEYS(fp); COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno); mx->mx_cursor.mc_snum = 1; mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB; mx->mx_cursor.mc_top = 0; mx->mx_cursor.mc_pg[0] = fp; mx->mx_cursor.mc_ki[0] = 0; if (mc->mc_db->md_flags & MDB_DUPFIXED) { mx->mx_db.md_flags = MDB_DUPFIXED; mx->mx_db.md_pad = fp->mp_pad; if (mc->mc_db->md_flags & MDB_INTEGERDUP) mx->mx_db.md_flags |= MDB_INTEGERKEY; } } DPRINTF("Sub-db %u for db %u root page %zu", mx->mx_cursor.mc_dbi, mc->mc_dbi, mx->mx_db.md_root); mx->mx_dbflag = (F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY)) ? DB_DIRTY : 0; mx->mx_dbx.md_name.mv_data = NODEKEY(node); mx->mx_dbx.md_name.mv_size = node->mn_ksize; #if UINT_MAX < SIZE_MAX if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t)) #ifdef MISALIGNED_OK mx->mx_dbx.md_cmp = mdb_cmp_long; #else mx->mx_dbx.md_cmp = mdb_cmp_cint; #endif #endif } /** Initialize a cursor for a given transaction and database. */ static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx) { mc->mc_orig = NULL; mc->mc_dbi = dbi; mc->mc_txn = txn; mc->mc_db = &txn->mt_dbs[dbi]; mc->mc_dbx = &txn->mt_dbxs[dbi]; mc->mc_dbflag = &txn->mt_dbflags[dbi]; mc->mc_snum = 0; mc->mc_top = 0; mc->mc_pg[0] = 0; mc->mc_flags = 0; if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { assert(mx != NULL); mc->mc_xcursor = mx; mdb_xcursor_init0(mc); } else { mc->mc_xcursor = NULL; } if (*mc->mc_dbflag & DB_STALE) { mdb_page_search(mc, NULL, MDB_PS_ROOTONLY); } } int mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret) { MDB_cursor *mc; MDB_xcursor *mx = NULL; size_t size = sizeof(MDB_cursor); if (txn == NULL || ret == NULL || dbi >= txn->mt_numdbs) return EINVAL; /* Allow read access to the freelist */ if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) return EINVAL; if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) size += sizeof(MDB_xcursor); if ((mc = malloc(size)) != NULL) { if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { mx = (MDB_xcursor *)(mc + 1); } mdb_cursor_init(mc, txn, dbi, mx); if (txn->mt_cursors) { mc->mc_next = txn->mt_cursors[dbi]; txn->mt_cursors[dbi] = mc; } mc->mc_flags |= C_ALLOCD; } else { return ENOMEM; } *ret = mc; return MDB_SUCCESS; } /* Return the count of duplicate data items for the current key */ int mdb_cursor_count(MDB_cursor *mc, size_t *countp) { MDB_node *leaf; if (mc == NULL || countp == NULL) return EINVAL; if (!(mc->mc_db->md_flags & MDB_DUPSORT)) return EINVAL; leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { *countp = 1; } else { if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) return EINVAL; *countp = mc->mc_xcursor->mx_db.md_entries; } return MDB_SUCCESS; } void mdb_cursor_close(MDB_cursor *mc) { if (mc != NULL) { /* remove from txn, if tracked */ if (mc->mc_txn->mt_cursors) { MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi]; while (*prev && *prev != mc) prev = &(*prev)->mc_next; if (*prev == mc) *prev = mc->mc_next; } if (mc->mc_flags & C_ALLOCD) free(mc); } } MDB_txn * mdb_cursor_txn(MDB_cursor *mc) { if (!mc) return NULL; return mc->mc_txn; } MDB_dbi mdb_cursor_dbi(MDB_cursor *mc) { if (!mc) return 0; return mc->mc_dbi; } /** Replace the key for a node with a new key. * @param[in] mp The page containing the node to operate on. * @param[in] indx The index of the node to operate on. * @param[in] key The new key to use. * @return 0 on success, non-zero on failure. */ static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key) { MDB_node *node; char *base; size_t len; int delta, delta0; indx_t ptr, i, numkeys; DKBUF; node = NODEPTR(mp, indx); ptr = mp->mp_ptrs[indx]; #if MDB_DEBUG { MDB_val k2; char kbuf2[(MAXKEYSIZE*2+1)]; k2.mv_data = NODEKEY(node); k2.mv_size = node->mn_ksize; DPRINTF("update key %u (ofs %u) [%s] to [%s] on page %zu", indx, ptr, mdb_dkey(&k2, kbuf2), DKEY(key), mp->mp_pgno); } #endif delta0 = delta = key->mv_size - node->mn_ksize; /* Must be 2-byte aligned. If new key is * shorter by 1, the shift will be skipped. */ delta += (delta & 1); if (delta) { if (delta > 0 && SIZELEFT(mp) < delta) { DPRINTF("OUCH! Not enough room, delta = %d", delta); return ENOSPC; } numkeys = NUMKEYS(mp); for (i = 0; i < numkeys; i++) { if (mp->mp_ptrs[i] <= ptr) mp->mp_ptrs[i] -= delta; } base = (char *)mp + mp->mp_upper; len = ptr - mp->mp_upper + NODESIZE; memmove(base - delta, base, len); mp->mp_upper -= delta; node = NODEPTR(mp, indx); } /* But even if no shift was needed, update ksize */ if (delta0) node->mn_ksize = key->mv_size; if (key->mv_size) memcpy(NODEKEY(node), key->mv_data, key->mv_size); return MDB_SUCCESS; } /** Move a node from csrc to cdst. */ static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst) { int rc; MDB_node *srcnode; MDB_val key, data; pgno_t srcpg; unsigned short flags; DKBUF; /* Mark src and dst as dirty. */ if ((rc = mdb_page_touch(csrc)) || (rc = mdb_page_touch(cdst))) return rc; if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */ key.mv_size = csrc->mc_db->md_pad; key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size); data.mv_size = 0; data.mv_data = NULL; srcpg = 0; flags = 0; } else { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]); assert(!((long)srcnode&1)); srcpg = NODEPGNO(srcnode); flags = srcnode->mn_flags; if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { unsigned int snum = csrc->mc_snum; MDB_node *s2; /* must find the lowest key below src */ mdb_page_search_root(csrc, NULL, 0); if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_size = csrc->mc_db->md_pad; key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); } else { s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); key.mv_size = NODEKSZ(s2); key.mv_data = NODEKEY(s2); } csrc->mc_snum = snum--; csrc->mc_top = snum; } else { key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } data.mv_size = NODEDSZ(srcnode); data.mv_data = NODEDATA(srcnode); } if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) { unsigned int snum = cdst->mc_snum; MDB_node *s2; MDB_val bkey; /* must find the lowest key below dst */ mdb_page_search_root(cdst, NULL, 0); if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) { bkey.mv_size = cdst->mc_db->md_pad; bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size); } else { s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0); bkey.mv_size = NODEKSZ(s2); bkey.mv_data = NODEKEY(s2); } cdst->mc_snum = snum--; cdst->mc_top = snum; rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &bkey); } DPRINTF("moving %s node %u [%s] on page %zu to node %u on page %zu", IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch", csrc->mc_ki[csrc->mc_top], DKEY(&key), csrc->mc_pg[csrc->mc_top]->mp_pgno, cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno); /* Add the node to the destination page. */ rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags); if (rc != MDB_SUCCESS) return rc; /* Delete the node from the source page. */ mdb_node_del(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size); { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = csrc->mc_dbi; MDB_page *mp = csrc->mc_pg[csrc->mc_top]; if (csrc->mc_flags & C_SUB) dbi--; for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (m2 == csrc) continue; if (csrc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) { m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top]; m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top]; } } } /* Update the parent separators. */ if (csrc->mc_ki[csrc->mc_top] == 0) { if (csrc->mc_ki[csrc->mc_top-1] != 0) { if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); } else { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } DPRINTF("update separator for source page %zu to [%s]", csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)); if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], &key)) != MDB_SUCCESS) return rc; } if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { MDB_val nullkey; nullkey.mv_size = 0; rc = mdb_update_key(csrc->mc_pg[csrc->mc_top], 0, &nullkey); assert(rc == MDB_SUCCESS); } } if (cdst->mc_ki[cdst->mc_top] == 0) { if (cdst->mc_ki[cdst->mc_top-1] != 0) { if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size); } else { srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0); key.mv_size = NODEKSZ(srcnode); key.mv_data = NODEKEY(srcnode); } DPRINTF("update separator for destination page %zu to [%s]", cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)); if ((rc = mdb_update_key(cdst->mc_pg[cdst->mc_top-1], cdst->mc_ki[cdst->mc_top-1], &key)) != MDB_SUCCESS) return rc; } if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) { MDB_val nullkey; nullkey.mv_size = 0; rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &nullkey); assert(rc == MDB_SUCCESS); } } return MDB_SUCCESS; } /** Merge one page into another. * The nodes from the page pointed to by \b csrc will * be copied to the page pointed to by \b cdst and then * the \b csrc page will be freed. * @param[in] csrc Cursor pointing to the source page. * @param[in] cdst Cursor pointing to the destination page. */ static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst) { int rc; indx_t i, j; MDB_node *srcnode; MDB_val key, data; unsigned nkeys; DPRINTF("merging page %zu into %zu", csrc->mc_pg[csrc->mc_top]->mp_pgno, cdst->mc_pg[cdst->mc_top]->mp_pgno); assert(csrc->mc_snum > 1); /* can't merge root page */ assert(cdst->mc_snum > 1); /* Mark dst as dirty. */ if ((rc = mdb_page_touch(cdst))) return rc; /* Move all nodes from src to dst. */ j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]); if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_size = csrc->mc_db->md_pad; key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]); for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) { rc = mdb_node_add(cdst, j, &key, NULL, 0, 0); if (rc != MDB_SUCCESS) return rc; key.mv_data = (char *)key.mv_data + key.mv_size; } } else { for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) { srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i); if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { unsigned int snum = csrc->mc_snum; MDB_node *s2; /* must find the lowest key below src */ mdb_page_search_root(csrc, NULL, 0); if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { key.mv_size = csrc->mc_db->md_pad; key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); } else { s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); key.mv_size = NODEKSZ(s2); key.mv_data = NODEKEY(s2); } csrc->mc_snum = snum--; csrc->mc_top = snum; } else { key.mv_size = srcnode->mn_ksize; key.mv_data = NODEKEY(srcnode); } data.mv_size = NODEDSZ(srcnode); data.mv_data = NODEDATA(srcnode); rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags); if (rc != MDB_SUCCESS) return rc; } } DPRINTF("dst page %zu now has %u keys (%.1f%% filled)", cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]), (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10); /* Unlink the src page from parent and add to free list. */ mdb_node_del(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0); if (csrc->mc_ki[csrc->mc_top-1] == 0) { key.mv_size = 0; if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], 0, &key)) != MDB_SUCCESS) return rc; } mdb_midl_append(&csrc->mc_txn->mt_free_pgs, csrc->mc_pg[csrc->mc_top]->mp_pgno); if (IS_LEAF(csrc->mc_pg[csrc->mc_top])) csrc->mc_db->md_leaf_pages--; else csrc->mc_db->md_branch_pages--; { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = csrc->mc_dbi; MDB_page *mp = cdst->mc_pg[cdst->mc_top]; if (csrc->mc_flags & C_SUB) dbi--; for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (csrc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3 == csrc) continue; if (m3->mc_snum < csrc->mc_snum) continue; if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) { m3->mc_pg[csrc->mc_top] = mp; m3->mc_ki[csrc->mc_top] += nkeys; } } } mdb_cursor_pop(csrc); return mdb_rebalance(csrc); } /** Copy the contents of a cursor. * @param[in] csrc The cursor to copy from. * @param[out] cdst The cursor to copy to. */ static void mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst) { unsigned int i; cdst->mc_txn = csrc->mc_txn; cdst->mc_dbi = csrc->mc_dbi; cdst->mc_db = csrc->mc_db; cdst->mc_dbx = csrc->mc_dbx; cdst->mc_snum = csrc->mc_snum; cdst->mc_top = csrc->mc_top; cdst->mc_flags = csrc->mc_flags; for (i=0; imc_snum; i++) { cdst->mc_pg[i] = csrc->mc_pg[i]; cdst->mc_ki[i] = csrc->mc_ki[i]; } } /** Rebalance the tree after a delete operation. * @param[in] mc Cursor pointing to the page where rebalancing * should begin. * @return 0 on success, non-zero on failure. */ static int mdb_rebalance(MDB_cursor *mc) { MDB_node *node; int rc; unsigned int ptop; MDB_cursor mn; #if MDB_DEBUG { pgno_t pgno; COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno); DPRINTF("rebalancing %s page %zu (has %u keys, %.1f%% full)", IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch", pgno, NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10); } #endif if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD) { #if MDB_DEBUG pgno_t pgno; COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno); DPRINTF("no need to rebalance page %zu, above fill threshold", pgno); #endif return MDB_SUCCESS; } if (mc->mc_snum < 2) { MDB_page *mp = mc->mc_pg[0]; if (NUMKEYS(mp) == 0) { DPUTS("tree is completely empty"); mc->mc_db->md_root = P_INVALID; mc->mc_db->md_depth = 0; mc->mc_db->md_leaf_pages = 0; mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); mc->mc_snum = 0; mc->mc_top = 0; { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; if (mc->mc_flags & C_SUB) dbi--; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (m2 == mc) continue; if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[0] == mp) { m3->mc_snum = 0; m3->mc_top = 0; } } } } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) { DPUTS("collapsing root page!"); mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0)); if ((rc = mdb_page_get(mc->mc_txn, mc->mc_db->md_root, &mc->mc_pg[0]))) return rc; mc->mc_db->md_depth--; mc->mc_db->md_branch_pages--; { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; if (mc->mc_flags & C_SUB) dbi--; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (m2 == mc) continue; if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (m3->mc_snum < mc->mc_snum) continue; if (m3->mc_pg[0] == mp) { m3->mc_pg[0] = mc->mc_pg[0]; } } } } else DPUTS("root page doesn't need rebalancing"); return MDB_SUCCESS; } /* The parent (branch page) must have at least 2 pointers, * otherwise the tree is invalid. */ ptop = mc->mc_top-1; assert(NUMKEYS(mc->mc_pg[ptop]) > 1); /* Leaf page fill factor is below the threshold. * Try to move keys from left or right neighbor, or * merge with a neighbor page. */ /* Find neighbors. */ mdb_cursor_copy(mc, &mn); mn.mc_xcursor = NULL; if (mc->mc_ki[ptop] == 0) { /* We're the leftmost leaf in our parent. */ DPUTS("reading right neighbor"); mn.mc_ki[ptop]++; node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top]))) return rc; mn.mc_ki[mn.mc_top] = 0; mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]); } else { /* There is at least one neighbor to the left. */ DPUTS("reading left neighbor"); mn.mc_ki[ptop]--; node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top]))) return rc; mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1; mc->mc_ki[mc->mc_top] = 0; } DPRINTF("found neighbor page %zu (%u keys, %.1f%% full)", mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10); /* If the neighbor page is above threshold and has at least two * keys, move one key from it. * * Otherwise we should try to merge them. */ if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) >= 2) return mdb_node_move(&mn, mc); else { /* FIXME: if (has_enough_room()) */ mc->mc_flags &= ~C_INITIALIZED; if (mc->mc_ki[ptop] == 0) return mdb_page_merge(&mn, mc); else return mdb_page_merge(mc, &mn); } } /** Complete a delete operation started by #mdb_cursor_del(). */ static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf) { int rc; /* add overflow pages to free list */ if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_BIGDATA)) { int i, ovpages; pgno_t pg; memcpy(&pg, NODEDATA(leaf), sizeof(pg)); ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize); mc->mc_db->md_overflow_pages -= ovpages; for (i=0; imc_txn->mt_free_pgs, pg); pg++; } } mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], mc->mc_db->md_pad); mc->mc_db->md_entries--; rc = mdb_rebalance(mc); if (rc != MDB_SUCCESS) mc->mc_txn->mt_flags |= MDB_TXN_ERROR; return rc; } int mdb_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) { MDB_cursor mc; MDB_xcursor mx; MDB_cursor_op op; MDB_val rdata, *xdata; int rc, exact; DKBUF; assert(key != NULL); DPRINTF("====> delete db %u key [%s]", dbi, DKEY(key)); if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) return EINVAL; if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { return EACCES; } if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { return EINVAL; } mdb_cursor_init(&mc, txn, dbi, &mx); exact = 0; if (data) { op = MDB_GET_BOTH; rdata = *data; xdata = &rdata; } else { op = MDB_SET; xdata = NULL; } rc = mdb_cursor_set(&mc, key, xdata, op, &exact); if (rc == 0) rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA); return rc; } /** Split a page and insert a new node. * @param[in,out] mc Cursor pointing to the page and desired insertion index. * The cursor will be updated to point to the actual page and index where * the node got inserted after the split. * @param[in] newkey The key for the newly inserted node. * @param[in] newdata The data for the newly inserted node. * @param[in] newpgno The page number, if the new node is a branch node. * @param[in] nflags The #NODE_ADD_FLAGS for the new node. * @return 0 on success, non-zero on failure. */ static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno, unsigned int nflags) { unsigned int flags; int rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1, did_split = 0; indx_t newindx; pgno_t pgno = 0; unsigned int i, j, split_indx, nkeys, pmax; MDB_node *node; MDB_val sepkey, rkey, xdata, *rdata = &xdata; MDB_page *copy; MDB_page *mp, *rp, *pp; unsigned int ptop; MDB_cursor mn; DKBUF; mp = mc->mc_pg[mc->mc_top]; newindx = mc->mc_ki[mc->mc_top]; DPRINTF("-----> splitting %s page %zu and adding [%s] at index %i", IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno, DKEY(newkey), mc->mc_ki[mc->mc_top]); /* Create a right sibling. */ if ((rp = mdb_page_new(mc, mp->mp_flags, 1)) == NULL) return ENOMEM; DPRINTF("new right sibling: page %zu", rp->mp_pgno); if (mc->mc_snum < 2) { if ((pp = mdb_page_new(mc, P_BRANCH, 1)) == NULL) return ENOMEM; /* shift current top to make room for new parent */ mc->mc_pg[1] = mc->mc_pg[0]; mc->mc_ki[1] = mc->mc_ki[0]; mc->mc_pg[0] = pp; mc->mc_ki[0] = 0; mc->mc_db->md_root = pp->mp_pgno; DPRINTF("root split! new root = %zu", pp->mp_pgno); mc->mc_db->md_depth++; new_root = 1; /* Add left (implicit) pointer. */ if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) { /* undo the pre-push */ mc->mc_pg[0] = mc->mc_pg[1]; mc->mc_ki[0] = mc->mc_ki[1]; mc->mc_db->md_root = mp->mp_pgno; mc->mc_db->md_depth--; return rc; } mc->mc_snum = 2; mc->mc_top = 1; ptop = 0; } else { ptop = mc->mc_top-1; DPRINTF("parent branch page is %zu", mc->mc_pg[ptop]->mp_pgno); } mc->mc_flags |= C_SPLITTING; mdb_cursor_copy(mc, &mn); mn.mc_pg[mn.mc_top] = rp; mn.mc_ki[ptop] = mc->mc_ki[ptop]+1; if (nflags & MDB_APPEND) { mn.mc_ki[mn.mc_top] = 0; sepkey = *newkey; split_indx = newindx; nkeys = 0; goto newsep; } nkeys = NUMKEYS(mp); split_indx = (nkeys + 1) / 2; if (newindx < split_indx) newpos = 0; if (IS_LEAF2(rp)) { char *split, *ins; int x; unsigned int lsize, rsize, ksize; /* Move half of the keys to the right sibling */ copy = NULL; x = mc->mc_ki[mc->mc_top] - split_indx; ksize = mc->mc_db->md_pad; split = LEAF2KEY(mp, split_indx, ksize); rsize = (nkeys - split_indx) * ksize; lsize = (nkeys - split_indx) * sizeof(indx_t); mp->mp_lower -= lsize; rp->mp_lower += lsize; mp->mp_upper += rsize - lsize; rp->mp_upper -= rsize - lsize; sepkey.mv_size = ksize; if (newindx == split_indx) { sepkey.mv_data = newkey->mv_data; } else { sepkey.mv_data = split; } if (x<0) { ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize); memcpy(rp->mp_ptrs, split, rsize); sepkey.mv_data = rp->mp_ptrs; memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize); memcpy(ins, newkey->mv_data, ksize); mp->mp_lower += sizeof(indx_t); mp->mp_upper -= ksize - sizeof(indx_t); } else { if (x) memcpy(rp->mp_ptrs, split, x * ksize); ins = LEAF2KEY(rp, x, ksize); memcpy(ins, newkey->mv_data, ksize); memcpy(ins+ksize, split + x * ksize, rsize - x * ksize); rp->mp_lower += sizeof(indx_t); rp->mp_upper -= ksize - sizeof(indx_t); mc->mc_ki[mc->mc_top] = x; mc->mc_pg[mc->mc_top] = rp; } goto newsep; } /* For leaf pages, check the split point based on what * fits where, since otherwise mdb_node_add can fail. * * This check is only needed when the data items are * relatively large, such that being off by one will * make the difference between success or failure. * When the size of the data items is much smaller than * one-half of a page, this check is irrelevant. */ if (IS_LEAF(mp)) { unsigned int psize, nsize; /* Maximum free space in an empty page */ pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ; nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata); if ((nkeys < 20) || (nsize > pmax/4)) { if (newindx <= split_indx) { psize = nsize; newpos = 0; for (i=0; imn_flags, F_BIGDATA)) psize += sizeof(pgno_t); else psize += NODEDSZ(node); psize += psize & 1; if (psize > pmax) { if (i == split_indx - 1 && newindx == split_indx) newpos = 1; else split_indx = i; break; } } } else { psize = nsize; for (i=nkeys-1; i>=split_indx; i--) { node = NODEPTR(mp, i); psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t); if (F_ISSET(node->mn_flags, F_BIGDATA)) psize += sizeof(pgno_t); else psize += NODEDSZ(node); psize += psize & 1; if (psize > pmax) { split_indx = i+1; break; } } } } } /* First find the separating key between the split pages. * The case where newindx == split_indx is ambiguous; the * new item could go to the new page or stay on the original * page. If newpos == 1 it goes to the new page. */ if (newindx == split_indx && newpos) { sepkey.mv_size = newkey->mv_size; sepkey.mv_data = newkey->mv_data; } else { node = NODEPTR(mp, split_indx); sepkey.mv_size = node->mn_ksize; sepkey.mv_data = NODEKEY(node); } newsep: DPRINTF("separator is [%s]", DKEY(&sepkey)); /* Copy separator key to the parent. */ if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) { mn.mc_snum--; mn.mc_top--; did_split = 1; rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0); /* root split? */ if (mn.mc_snum == mc->mc_snum) { mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top]; mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top]; mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop]; mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop]; mc->mc_snum++; mc->mc_top++; ptop++; } /* Right page might now have changed parent. * Check if left page also changed parent. */ if (mn.mc_pg[ptop] != mc->mc_pg[ptop] && mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) { for (i=0; imc_pg[i] = mn.mc_pg[i]; mc->mc_ki[i] = mn.mc_ki[i]; } mc->mc_pg[ptop] = mn.mc_pg[ptop]; mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1; } } else { mn.mc_top--; rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0); mn.mc_top++; } mc->mc_flags ^= C_SPLITTING; if (rc != MDB_SUCCESS) { return rc; } if (nflags & MDB_APPEND) { mc->mc_pg[mc->mc_top] = rp; mc->mc_ki[mc->mc_top] = 0; rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags); if (rc) return rc; for (i=0; imc_top; i++) mc->mc_ki[i] = mn.mc_ki[i]; goto done; } if (IS_LEAF2(rp)) { goto done; } /* Move half of the keys to the right sibling. */ /* grab a page to hold a temporary copy */ copy = mdb_page_malloc(mc); if (copy == NULL) return ENOMEM; copy->mp_pgno = mp->mp_pgno; copy->mp_flags = mp->mp_flags; copy->mp_lower = PAGEHDRSZ; copy->mp_upper = mc->mc_txn->mt_env->me_psize; mc->mc_pg[mc->mc_top] = copy; for (i = j = 0; i <= nkeys; j++) { if (i == split_indx) { /* Insert in right sibling. */ /* Reset insert index for right sibling. */ if (i != newindx || (newpos ^ ins_new)) { j = 0; mc->mc_pg[mc->mc_top] = rp; } } if (i == newindx && !ins_new) { /* Insert the original entry that caused the split. */ rkey.mv_data = newkey->mv_data; rkey.mv_size = newkey->mv_size; if (IS_LEAF(mp)) { rdata = newdata; } else pgno = newpgno; flags = nflags; ins_new = 1; /* Update index for the new key. */ mc->mc_ki[mc->mc_top] = j; } else if (i == nkeys) { break; } else { node = NODEPTR(mp, i); rkey.mv_data = NODEKEY(node); rkey.mv_size = node->mn_ksize; if (IS_LEAF(mp)) { xdata.mv_data = NODEDATA(node); xdata.mv_size = NODEDSZ(node); rdata = &xdata; } else pgno = NODEPGNO(node); flags = node->mn_flags; i++; } if (!IS_LEAF(mp) && j == 0) { /* First branch index doesn't need key data. */ rkey.mv_size = 0; } rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags); if (rc) break; } nkeys = NUMKEYS(copy); for (i=0; imp_ptrs[i] = copy->mp_ptrs[i]; mp->mp_lower = copy->mp_lower; mp->mp_upper = copy->mp_upper; memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1), mc->mc_txn->mt_env->me_psize - copy->mp_upper); /* reset back to original page */ if (newindx < split_indx || (!newpos && newindx == split_indx)) { mc->mc_pg[mc->mc_top] = mp; if (nflags & MDB_RESERVE) { node = NODEPTR(mp, mc->mc_ki[mc->mc_top]); if (!(node->mn_flags & F_BIGDATA)) newdata->mv_data = NODEDATA(node); } } else { mc->mc_ki[ptop]++; } /* return tmp page to freelist */ copy->mp_next = mc->mc_txn->mt_env->me_dpages; VGMEMP_FREE(mc->mc_txn->mt_env, copy); mc->mc_txn->mt_env->me_dpages = copy; done: { /* Adjust other cursors pointing to mp */ MDB_cursor *m2, *m3; MDB_dbi dbi = mc->mc_dbi; int fixup = NUMKEYS(mp); if (mc->mc_flags & C_SUB) dbi--; for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { if (m2 == mc) continue; if (mc->mc_flags & C_SUB) m3 = &m2->mc_xcursor->mx_cursor; else m3 = m2; if (!(m3->mc_flags & C_INITIALIZED)) continue; if (m3->mc_flags & C_SPLITTING) continue; if (new_root) { int k; /* root split */ for (k=m3->mc_top; k>=0; k--) { m3->mc_ki[k+1] = m3->mc_ki[k]; m3->mc_pg[k+1] = m3->mc_pg[k]; } if (m3->mc_ki[0] >= split_indx) { m3->mc_ki[0] = 1; } else { m3->mc_ki[0] = 0; } m3->mc_pg[0] = mc->mc_pg[0]; m3->mc_snum++; m3->mc_top++; } if (m3->mc_pg[mc->mc_top] == mp) { if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE)) m3->mc_ki[mc->mc_top]++; if (m3->mc_ki[mc->mc_top] >= fixup) { m3->mc_pg[mc->mc_top] = rp; m3->mc_ki[mc->mc_top] -= fixup; m3->mc_ki[ptop] = mn.mc_ki[ptop]; } } else if (!did_split && m3->mc_pg[ptop] == mc->mc_pg[ptop] && m3->mc_ki[ptop] >= mc->mc_ki[ptop]) { m3->mc_ki[ptop]++; } } } return rc; } int mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned int flags) { MDB_cursor mc; MDB_xcursor mx; assert(key != NULL); assert(data != NULL); if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) return EINVAL; if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { return EACCES; } if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { return EINVAL; } if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND)) != flags) return EINVAL; mdb_cursor_init(&mc, txn, dbi, &mx); return mdb_cursor_put(&mc, key, data, flags); } /** Only a subset of the @ref mdb_env flags can be changed * at runtime. Changing other flags requires closing the environment * and re-opening it with the new flags. */ #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC) int mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff) { if ((flag & CHANGEABLE) != flag) return EINVAL; if (onoff) env->me_flags |= flag; else env->me_flags &= ~flag; return MDB_SUCCESS; } int mdb_env_get_flags(MDB_env *env, unsigned int *arg) { if (!env || !arg) return EINVAL; *arg = env->me_flags; return MDB_SUCCESS; } int mdb_env_get_path(MDB_env *env, const char **arg) { if (!env || !arg) return EINVAL; *arg = env->me_path; return MDB_SUCCESS; } /** Common code for #mdb_stat() and #mdb_env_stat(). * @param[in] env the environment to operate in. * @param[in] db the #MDB_db record containing the stats to return. * @param[out] arg the address of an #MDB_stat structure to receive the stats. * @return 0, this function always succeeds. */ static int mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg) { arg->ms_psize = env->me_psize; arg->ms_depth = db->md_depth; arg->ms_branch_pages = db->md_branch_pages; arg->ms_leaf_pages = db->md_leaf_pages; arg->ms_overflow_pages = db->md_overflow_pages; arg->ms_entries = db->md_entries; return MDB_SUCCESS; } int mdb_env_stat(MDB_env *env, MDB_stat *arg) { int toggle; if (env == NULL || arg == NULL) return EINVAL; toggle = mdb_env_pick_meta(env); return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg); } /** Set the default comparison functions for a database. * Called immediately after a database is opened to set the defaults. * The user can then override them with #mdb_set_compare() or * #mdb_set_dupsort(). * @param[in] txn A transaction handle returned by #mdb_txn_begin() * @param[in] dbi A database handle returned by #mdb_open() */ static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi) { uint16_t f = txn->mt_dbs[dbi].md_flags; txn->mt_dbxs[dbi].md_cmp = (f & MDB_REVERSEKEY) ? mdb_cmp_memnr : (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn; txn->mt_dbxs[dbi].md_dcmp = !(f & MDB_DUPSORT) ? 0 : ((f & MDB_INTEGERDUP) ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint) : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn)); } int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi) { MDB_val key, data; MDB_dbi i; MDB_cursor mc; int rc, dbflag, exact; unsigned int unused = 0; size_t len; if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) { mdb_default_cmp(txn, FREE_DBI); } /* main DB? */ if (!name) { *dbi = MAIN_DBI; if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY)) txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY)); mdb_default_cmp(txn, MAIN_DBI); return MDB_SUCCESS; } if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) { mdb_default_cmp(txn, MAIN_DBI); } /* Is the DB already open? */ len = strlen(name); for (i=2; imt_numdbs; i++) { if (!txn->mt_dbxs[i].md_name.mv_size) { /* Remember this free slot */ if (!unused) unused = i; continue; } if (len == txn->mt_dbxs[i].md_name.mv_size && !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) { *dbi = i; return MDB_SUCCESS; } } /* If no free slot and max hit, fail */ if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs - 1) return ENFILE; /* Find the DB info */ dbflag = 0; exact = 0; key.mv_size = len; key.mv_data = (void *)name; mdb_cursor_init(&mc, txn, MAIN_DBI, NULL); rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact); if (rc == MDB_SUCCESS) { /* make sure this is actually a DB */ MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]); if (!(node->mn_flags & F_SUBDATA)) return EINVAL; } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) { /* Create if requested */ MDB_db dummy; data.mv_size = sizeof(MDB_db); data.mv_data = &dummy; memset(&dummy, 0, sizeof(dummy)); dummy.md_root = P_INVALID; dummy.md_flags = flags & 0xffff; rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA); dbflag = DB_DIRTY; } /* OK, got info, add to table */ if (rc == MDB_SUCCESS) { unsigned int slot = unused ? unused : txn->mt_numdbs; txn->mt_dbxs[slot].md_name.mv_data = strdup(name); txn->mt_dbxs[slot].md_name.mv_size = len; txn->mt_dbxs[slot].md_rel = NULL; txn->mt_dbflags[slot] = dbflag; memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db)); *dbi = slot; txn->mt_env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags; mdb_default_cmp(txn, slot); if (!unused) { txn->mt_numdbs++; txn->mt_env->me_numdbs++; } } return rc; } int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg) { if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs) return EINVAL; return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg); } void mdb_close(MDB_env *env, MDB_dbi dbi) { char *ptr; if (dbi <= MAIN_DBI || dbi >= env->me_numdbs) return; ptr = env->me_dbxs[dbi].md_name.mv_data; env->me_dbxs[dbi].md_name.mv_data = NULL; env->me_dbxs[dbi].md_name.mv_size = 0; free(ptr); } /** Add all the DB's pages to the free list. * @param[in] mc Cursor on the DB to free. * @param[in] subs non-Zero to check for sub-DBs in this DB. * @return 0 on success, non-zero on failure. */ static int mdb_drop0(MDB_cursor *mc, int subs) { int rc; rc = mdb_page_search(mc, NULL, 0); if (rc == MDB_SUCCESS) { MDB_node *ni; MDB_cursor mx; unsigned int i; /* LEAF2 pages have no nodes, cannot have sub-DBs */ if (!subs || IS_LEAF2(mc->mc_pg[mc->mc_top])) mdb_cursor_pop(mc); mdb_cursor_copy(mc, &mx); while (mc->mc_snum > 0) { if (IS_LEAF(mc->mc_pg[mc->mc_top])) { for (i=0; imc_pg[mc->mc_top]); i++) { ni = NODEPTR(mc->mc_pg[mc->mc_top], i); if (ni->mn_flags & F_SUBDATA) { mdb_xcursor_init1(mc, ni); rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0); if (rc) return rc; } } } else { for (i=0; imc_pg[mc->mc_top]); i++) { pgno_t pg; ni = NODEPTR(mc->mc_pg[mc->mc_top], i); pg = NODEPGNO(ni); /* free it */ mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg); } } if (!mc->mc_top) break; rc = mdb_cursor_sibling(mc, 1); if (rc) { /* no more siblings, go back to beginning * of previous level. (stack was already popped * by mdb_cursor_sibling) */ for (i=1; imc_top; i++) mc->mc_pg[i] = mx.mc_pg[i]; } } /* free it */ mdb_midl_append(&mc->mc_txn->mt_free_pgs, mc->mc_db->md_root); } return 0; } int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del) { MDB_cursor *mc; int rc; if (!txn || !dbi || dbi >= txn->mt_numdbs) return EINVAL; if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) return EACCES; rc = mdb_cursor_open(txn, dbi, &mc); if (rc) return rc; rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT); if (rc) goto leave; /* Can't delete the main DB */ if (del && dbi > MAIN_DBI) { rc = mdb_del(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL); if (!rc) mdb_close(txn->mt_env, dbi); } else { txn->mt_dbflags[dbi] |= DB_DIRTY; txn->mt_dbs[dbi].md_depth = 0; txn->mt_dbs[dbi].md_branch_pages = 0; txn->mt_dbs[dbi].md_leaf_pages = 0; txn->mt_dbs[dbi].md_overflow_pages = 0; txn->mt_dbs[dbi].md_entries = 0; txn->mt_dbs[dbi].md_root = P_INVALID; } leave: mdb_cursor_close(mc); return rc; } int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) { if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) return EINVAL; txn->mt_dbxs[dbi].md_cmp = cmp; return MDB_SUCCESS; } int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) { if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) return EINVAL; txn->mt_dbxs[dbi].md_dcmp = cmp; return MDB_SUCCESS; } int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel) { if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) return EINVAL; txn->mt_dbxs[dbi].md_rel = rel; return MDB_SUCCESS; } int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx) { if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) return EINVAL; txn->mt_dbxs[dbi].md_relctx = ctx; return MDB_SUCCESS; } /** @} */