diff options
Diffstat (limited to 'db.go')
| -rw-r--r-- | db.go | 1165 |
1 files changed, 1165 insertions, 0 deletions
@@ -8,12 +8,1177 @@ const ( IntegerDupKey ) +// TODO: #define MDB_FATAL_ERROR 0x80000000U /** Failed to update the meta page. Probably an I/O error. */ +// TODO: #define MDB_ENV_ACTIVE 0x20000000U /** Some fields are initialized. */ +// TODO: #define MDB_ENV_TXKEY 0x10000000U /** me_txkey is set */ +// TODO: #define MDB_LIVE_READER 0x08000000U /** Have liveness lock in reader table */ + +// 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. +// TODO: #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT) +// TODO: #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD) + type DB interface { } type db struct { + sync.Mutex + file os.File + flags int + pageSize int + osPageSize int + readers []*reader + buckets []*bucket + xbuckets []*bucketx /**< array of static DB info */ + bucketFlags []int /**< array of flags from MDB_db.md_flags */ + path string + mmap []byte + mmapSize int /**< size of the data memory map */ + size int /**< current file size */ + meta1 []byte + meta2 []byte + pbuf []byte + transaction *transaction /**< current write transaction */ + maxPageNumber int /**< me_mapsize / me_psize */ + pageState pageStage /**< state of old pages from freeDB */ + dpages []*page /**< list of malloc'd blocks for re-use */ + freePageNumbers []int /** IDL of pages that became unused in a write txn */ + dirtyPageNumbers []int /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */ + maxFreeOnePage int /** Max number of freelist items that can fit in a single overflow page */ + maxNodeSize int /** Max size of a node on a page */ + maxKeySize int /**< max size of a key */ } func NewDB() DB { return &db{} } + +func (db *db) Path() string { + return db.path +} + +func (db *db) freePage(p *page) { + /* + mp->mp_next = env->me_dpages; + VGMEMP_FREE(env, mp); + env->me_dpages = mp; + */ +} + +func (db *db) freeDirtyPage(p *page) { + /* + if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) { + mdb_page_free(env, dp); + } else { + // large pages just get freed directly + VGMEMP_FREE(env, dp); + free(dp); + } + */ +} + +func (db *db) freeAllDirtyPages(p *page) { + /* + MDB_env *env = txn->mt_env; + MDB_ID2L dl = txn->mt_u.dirty_list; + unsigned i, n = dl[0].mid; + + for (i = 1; i <= n; i++) { + mdb_dpage_free(env, dl[i].mptr); + } + dl[0].mid = 0; + */ +} + +func (db *db) sync(force bool) error { + /* + int rc = 0; + if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) { + if (env->me_flags & MDB_WRITEMAP) { + int flags = ((env->me_flags & MDB_MAPASYNC) && !force) + ? MS_ASYNC : MS_SYNC; + if (MDB_MSYNC(env->me_map, env->me_mapsize, flags)) + rc = ErrCode(); +#ifdef _WIN32 + else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd)) + rc = ErrCode(); +#endif + } else { + if (MDB_FDATASYNC(env->me_fd)) + rc = ErrCode(); + } + } + return rc; + */ + return nil +} + +func (db *db) Transaction(parent *transaction, flags int) (*transaction, error) { + /* + MDB_txn *txn; + MDB_ntxn *ntxn; + int rc, size, tsize = sizeof(MDB_txn); + + if (env->me_flags & MDB_FATAL_ERROR) { + DPUTS("environment had fatal error, must shutdown!"); + return MDB_PANIC; + } + if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY)) + return EACCES; + if (parent) { + // Nested transactions: Max 1 child, write txns only, no writemap + if (parent->mt_child || + (flags & MDB_RDONLY) || + (parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) || + (env->me_flags & MDB_WRITEMAP)) + { + return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN; + } + tsize = sizeof(MDB_ntxn); + } + size = tsize + 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 *) ((char *)txn + tsize); + 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) { + unsigned int i; + txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE); + if (!txn->mt_u.dirty_list || + !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX))) + { + free(txn->mt_u.dirty_list); + free(txn); + return ENOMEM; + } + txn->mt_txnid = parent->mt_txnid; + txn->mt_dirty_room = parent->mt_dirty_room; + txn->mt_u.dirty_list[0].mid = 0; + txn->mt_spill_pgs = NULL; + txn->mt_next_pgno = parent->mt_next_pgno; + parent->mt_child = txn; + txn->mt_parent = parent; + txn->mt_numdbs = parent->mt_numdbs; + txn->mt_flags = parent->mt_flags; + txn->mt_dbxs = parent->mt_dbxs; + memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db)); + // Copy parent's mt_dbflags, but clear DB_NEW + for (i=0; i<txn->mt_numdbs; i++) + txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW; + rc = 0; + ntxn = (MDB_ntxn *)txn; + ntxn->mnt_pgstate = env->me_pgstate; // save parent me_pghead & co + if (env->me_pghead) { + size = MDB_IDL_SIZEOF(env->me_pghead); + env->me_pghead = mdb_midl_alloc(env->me_pghead[0]); + if (env->me_pghead) + memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size); + else + rc = ENOMEM; + } + if (!rc) + rc = mdb_cursor_shadow(parent, txn); + if (rc) + mdb_txn_reset0(txn, "beginchild-fail"); + } else { + rc = mdb_txn_renew0(txn); + } + if (rc) + free(txn); + else { + *ret = txn; + DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u", + txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', + (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root)); + } + + return rc; + */ + return nil +} + +// 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. +func (db *db) readHeader(meta *meta) error { + /* + MDB_metabuf pbuf; + MDB_page *p; + MDB_meta *m; + int i, rc, off; + enum { Size = sizeof(pbuf) }; + + // We don't know the page size yet, so use a minimum value. + // Read both meta pages so we can use the latest one. + + for (i=off=0; i<2; i++, off = meta->mm_psize) { +#ifdef _WIN32 + DWORD len; + OVERLAPPED ov; + memset(&ov, 0, sizeof(ov)); + ov.Offset = off; + rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1; + if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF) + rc = 0; +#else + rc = pread(env->me_fd, &pbuf, Size, off); +#endif + if (rc != Size) { + if (rc == 0 && off == 0) + return ENOENT; + rc = rc < 0 ? (int) ErrCode() : MDB_INVALID; + DPRINTF(("read: %s", mdb_strerror(rc))); + return rc; + } + + p = (MDB_page *)&pbuf; + + if (!F_ISSET(p->mp_flags, P_META)) { + DPRINTF(("page %"Z"u not a meta page", p->mp_pgno)); + return MDB_INVALID; + } + + m = METADATA(p); + if (m->mm_magic != MDB_MAGIC) { + DPUTS("meta has invalid magic"); + return MDB_INVALID; + } + + if (m->mm_version != MDB_DATA_VERSION) { + DPRINTF(("database is version %u, expected version %u", + m->mm_version, MDB_DATA_VERSION)); + return MDB_VERSION_MISMATCH; + } + + if (off == 0 || m->mm_txnid > meta->mm_txnid) + *meta = *m; + } + return 0; + */ + return nil +} + +// 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. +func (db *db) initMeta(meta *meta) error { + /* + MDB_page *p, *q; + int rc; + unsigned int psize; +#ifdef _WIN32 + DWORD len; + OVERLAPPED ov; + memset(&ov, 0, sizeof(ov)); +#define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \ + ov.Offset = pos; \ + rc = WriteFile(fd, ptr, size, &len, &ov); } while(0) +#else + int len; +#define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \ + len = pwrite(fd, ptr, size, pos); \ + rc = (len >= 0); } while(0) +#endif + + DPUTS("writing new meta page"); + + psize = env->me_psize; + + meta->mm_magic = MDB_MAGIC; + meta->mm_version = MDB_DATA_VERSION; + meta->mm_mapsize = env->me_mapsize; + 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; + *(MDB_meta *)METADATA(p) = *meta; + + q = (MDB_page *)((char *)p + psize); + q->mp_pgno = 1; + q->mp_flags = P_META; + *(MDB_meta *)METADATA(q) = *meta; + + DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0); + if (!rc) + rc = ErrCode(); + else if ((unsigned) len == psize * 2) + rc = MDB_SUCCESS; + else + rc = ENOSPC; + free(p); + return rc; + */ + return nil +} + +// Check both meta pages to see which one is newer. +// @param[in] env the environment handle +// @return meta toggle (0 or 1). +func (db *db) pickMeta() int { + /* + return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid); + */ + return 0 +} + +func (db *db) Create() error { + /* + MDB_env *e; + + e = calloc(1, sizeof(MDB_env)); + if (!e) + return ENOMEM; + + e->me_maxreaders = DEFAULT_READERS; + e->me_maxdbs = e->me_numdbs = 2; + e->me_fd = INVALID_HANDLE_VALUE; + e->me_lfd = INVALID_HANDLE_VALUE; + e->me_mfd = INVALID_HANDLE_VALUE; +#ifdef MDB_USE_POSIX_SEM + e->me_rmutex = SEM_FAILED; + e->me_wmutex = SEM_FAILED; +#endif + e->me_pid = getpid(); + GET_PAGESIZE(e->me_os_psize); + VGMEMP_CREATE(e,0,0); + *env = e; + return MDB_SUCCESS; + */ + return nil +} + +// int mdb_env_map(MDB_env *env, void *addr, int newsize) +func (db *db) openMmap(newsize int) { + /* + MDB_page *p; + unsigned int flags = env->me_flags; +#ifdef _WIN32 + int rc; + HANDLE mh; + LONG sizelo, sizehi; + sizelo = env->me_mapsize & 0xffffffff; + sizehi = env->me_mapsize >> 16 >> 16; // only needed on Win64 + + // Windows won't create mappings for zero length files. + // Just allocate the maxsize right now. + if (newsize) { + if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo + || !SetEndOfFile(env->me_fd) + || SetFilePointer(env->me_fd, 0, NULL, 0) != 0) + return ErrCode(); + } + mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ? + PAGE_READWRITE : PAGE_READONLY, + sizehi, sizelo, NULL); + if (!mh) + return ErrCode(); + env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ? + FILE_MAP_WRITE : FILE_MAP_READ, + 0, 0, env->me_mapsize, addr); + rc = env->me_map ? 0 : ErrCode(); + CloseHandle(mh); + if (rc) + return rc; +#else + int prot = PROT_READ; + if (flags & MDB_WRITEMAP) { + prot |= PROT_WRITE; + if (ftruncate(env->me_fd, env->me_mapsize) < 0) + return ErrCode(); + } + env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED, + env->me_fd, 0); + if (env->me_map == MAP_FAILED) { + env->me_map = NULL; + return ErrCode(); + } + + if (flags & MDB_NORDAHEAD) { + // Turn off readahead. It's harmful when the DB is larger than RAM. +#ifdef MADV_RANDOM + madvise(env->me_map, env->me_mapsize, MADV_RANDOM); +#else +#ifdef POSIX_MADV_RANDOM + posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM); +#endif // POSIX_MADV_RANDOM +#endif // MADV_RANDOM + } +#endif // _WIN32 + + // Can happen because the address argument to mmap() is just a + // hint. mmap() can pick another, e.g. if the range is in use. + // The MAP_FIXED flag would prevent that, but then mmap could + // instead unmap existing pages to make room for the new map. + if (addr && env->me_map != addr) + return EBUSY; // TODO: Make a new MDB_* error code? + + p = (MDB_page *)env->me_map; + env->me_metas[0] = METADATA(p); + env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize); + + return MDB_SUCCESS; + */ + return nil +} + +func (db *db) setMapSize(size int) error { + /* + // If env is already open, caller is responsible for making + // sure there are no active txns. + if (env->me_map) { + int rc; + void *old; + if (env->me_txn) + return EINVAL; + if (!size) + size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize; + else if (size < env->me_mapsize) { + // If the configured size is smaller, make sure it's + // still big enough. Silently round up to minimum if not. + size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize; + if (size < minsize) + size = minsize; + } + munmap(env->me_map, env->me_mapsize); + env->me_mapsize = size; + old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL; + rc = mdb_env_map(env, old, 1); + if (rc) + return rc; + } + env->me_mapsize = size; + if (env->me_psize) + env->me_maxpg = env->me_mapsize / env->me_psize; + return MDB_SUCCESS; + */ + return nil +} + +func (db *db) setMaxBucketCount(count int) error { + /* + if (env->me_map) + return EINVAL; + env->me_maxdbs = dbs + 2; // Named databases + main and free DB + return MDB_SUCCESS; + */ + return nil +} + +func (db *db) setMaxReaderCount(count int) error { + /* + if (env->me_map || readers < 1) + return EINVAL; + env->me_maxreaders = readers; + return MDB_SUCCESS; + */ +} + +func (db *db) getMaxReaderCount(count int) (int, error) { + /* + if (!env || !readers) + return EINVAL; + *readers = env->me_maxreaders; + return MDB_SUCCESS; + */ + return 0, nil +} + +// Further setup required for opening an MDB environment +func (db *db) open() error { + /* + unsigned int flags = env->me_flags; + int i, newenv = 0, rc; + MDB_meta meta; + +#ifdef _WIN32 + // See if we should use QueryLimited + rc = GetVersion(); + if ((rc & 0xff) > 5) + env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION; + else + env->me_pidquery = PROCESS_QUERY_INFORMATION; +#endif // _WIN32 + + memset(&meta, 0, sizeof(meta)); + + if ((i = mdb_env_read_header(env, &meta)) != 0) { + if (i != ENOENT) + return i; + DPUTS("new mdbenv"); + newenv = 1; + env->me_psize = env->me_os_psize; + if (env->me_psize > MAX_PAGESIZE) + env->me_psize = MAX_PAGESIZE; + } else { + env->me_psize = meta.mm_psize; + } + + // Was a mapsize configured? + if (!env->me_mapsize) { + // If this is a new environment, take the default, + // else use the size recorded in the existing env. + env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize; + } else if (env->me_mapsize < meta.mm_mapsize) { + // If the configured size is smaller, make sure it's + // still big enough. Silently round up to minimum if not. + size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize; + if (env->me_mapsize < minsize) + env->me_mapsize = minsize; + } + + rc = mdb_env_map(env, meta.mm_address, newenv); + if (rc) + return rc; + + if (newenv) { + if (flags & MDB_FIXEDMAP) + meta.mm_address = env->me_map; + i = mdb_env_init_meta(env, &meta); + if (i != MDB_SUCCESS) { + return i; + } + } + + env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1; + env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2) + - sizeof(indx_t); +#if !(MDB_MAXKEYSIZE) + env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db)); +#endif + env->me_maxpg = env->me_mapsize / env->me_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: %"Z"u", db->md_entries)); + DPRINTF(("branch pages: %"Z"u", db->md_branch_pages)); + DPRINTF(("leaf pages: %"Z"u", db->md_leaf_pages)); + DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages)); + DPRINTF(("root: %"Z"u", db->md_root)); + } +#endif + + return MDB_SUCCESS; + */ + return nil +} + +func (db *db) Open(path string, flags int, mode uint) error { + /* + int oflags, rc, len, excl = -1; + char *lpath, *dpath; + + if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS))) + return EINVAL; + + 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_SUCCESS; + flags |= env->me_flags; + if (flags & MDB_RDONLY) { + // silently ignore WRITEMAP when we're only getting read access + flags &= ~MDB_WRITEMAP; + } else { + if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) && + (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2))))) + rc = ENOMEM; + } + env->me_flags = flags |= MDB_ENV_ACTIVE; + if (rc) + goto leave; + + env->me_path = strdup(path); + 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_path && env->me_dbflags)) { + rc = ENOMEM; + goto leave; + } + + // For RDONLY, get lockfile after we know datafile exists + if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) { + 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 ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) { + rc = mdb_env_setup_locks(env, lpath, mode, &excl); + if (rc) + goto leave; + } + + if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) { + if (flags & (MDB_RDONLY|MDB_WRITEMAP)) { + env->me_mfd = env->me_fd; + } else { + // Synchronous fd for meta writes. Needed even with + // MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset. +#ifdef _WIN32 + len = OPEN_EXISTING; + env->me_mfd = CreateFile(dpath, oflags, + FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len, + mode | FILE_FLAG_WRITE_THROUGH, NULL); +#else + oflags &= ~O_CREAT; + env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode); +#endif + if (env->me_mfd == INVALID_HANDLE_VALUE) { + rc = ErrCode(); + goto leave; + } + } + DPRINTF(("opened dbenv %p", (void *) env)); + if (excl > 0) { + rc = mdb_env_share_locks(env, &excl); + if (rc) + goto leave; + } + if (!((flags & MDB_RDONLY) || + (env->me_pbuf = calloc(1, env->me_psize)))) + rc = ENOMEM; + } + +leave: + if (rc) { + mdb_env_close0(env, excl); + } + free(lpath); + return rc; + */ + return nil +} + +// Destroy resources from mdb_env_open(), clear our readers & DBIs +func (db *db) close0(excl) { + /* + int i; + + if (!(env->me_flags & MDB_ENV_ACTIVE)) + return; + + // Doing this here since me_dbxs may not exist during mdb_env_close + for (i = env->me_maxdbs; --i > MAIN_DBI; ) + free(env->me_dbxs[i].md_name.mv_data); + + free(env->me_pbuf); + free(env->me_dbflags); + free(env->me_dbxs); + free(env->me_path); + free(env->me_dirty_list); + mdb_midl_free(env->me_free_pgs); + + if (env->me_flags & MDB_ENV_TXKEY) { + pthread_key_delete(env->me_txkey); +#ifdef _WIN32 + // Delete our key from the global list + for (i=0; i<mdb_tls_nkeys; i++) + if (mdb_tls_keys[i] == env->me_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 && env->me_mfd != INVALID_HANDLE_VALUE) + (void) close(env->me_mfd); + if (env->me_fd != INVALID_HANDLE_VALUE) + (void) close(env->me_fd); + if (env->me_txns) { + MDB_PID_T pid = env->me_pid; + // Clearing readers is done in this function because + // me_txkey with its destructor must be disabled first. + for (i = env->me_numreaders; --i >= 0; ) + if (env->me_txns->mti_readers[i].mr_pid == pid) + env->me_txns->mti_readers[i].mr_pid = 0; +#ifdef _WIN32 + if (env->me_rmutex) { + CloseHandle(env->me_rmutex); + if (env->me_wmutex) CloseHandle(env->me_wmutex); + } + // Windows automatically destroys the mutexes when + // the last handle closes. +#elif defined(MDB_USE_POSIX_SEM) + if (env->me_rmutex != SEM_FAILED) { + sem_close(env->me_rmutex); + if (env->me_wmutex != SEM_FAILED) + sem_close(env->me_wmutex); + // If we have the filelock: If we are the + // only remaining user, clean up semaphores. + if (excl == 0) + mdb_env_excl_lock(env, &excl); + if (excl > 0) { + sem_unlink(env->me_txns->mti_rmname); + sem_unlink(env->me_txns->mti_wmname); + } + } +#endif + munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo)); + } + if (env->me_lfd != INVALID_HANDLE_VALUE) { +#ifdef _WIN32 + if (excl >= 0) { + // Unlock the lockfile. Windows would have unlocked it + // after closing anyway, but not necessarily at once. + UnlockFile(env->me_lfd, 0, 0, 1, 0); + } +#endif + (void) close(env->me_lfd); + } + + env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY); + */ +} + +func (db *db) copyfd(handle int) error { + /* + MDB_txn *txn = NULL; + int rc; + size_t wsize; + char *ptr; +#ifdef _WIN32 + DWORD len, w2; +#define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL) +#else + ssize_t len; + size_t w2; +#define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0) +#endif + + // Do the lock/unlock of the reader mutex before starting the + // write txn. Otherwise other read txns could block writers. + rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn); + if (rc) + return rc; + + if (env->me_txns) { + // We must start the actual read txn after blocking writers + mdb_txn_reset0(txn, "reset-stage1"); + + // Temporarily block writers until we snapshot the meta pages + LOCK_MUTEX_W(env); + + rc = mdb_txn_renew0(txn); + if (rc) { + UNLOCK_MUTEX_W(env); + goto leave; + } + } + + wsize = env->me_psize * 2; + ptr = env->me_map; + w2 = wsize; + while (w2 > 0) { + DO_WRITE(rc, fd, ptr, w2, len); + if (!rc) { + rc = ErrCode(); + break; + } else if (len > 0) { + rc = MDB_SUCCESS; + ptr += len; + w2 -= len; + continue; + } else { + // Non-blocking or async handles are not supported + rc = EIO; + break; + } + } + if (env->me_txns) + UNLOCK_MUTEX_W(env); + + if (rc) + goto leave; + + wsize = txn->mt_next_pgno * env->me_psize - wsize; + while (wsize > 0) { + if (wsize > MAX_WRITE) + w2 = MAX_WRITE; + else + w2 = wsize; + DO_WRITE(rc, fd, ptr, w2, len); + if (!rc) { + rc = ErrCode(); + break; + } else if (len > 0) { + rc = MDB_SUCCESS; + ptr += len; + wsize -= len; + continue; + } else { + rc = EIO; + break; + } + } + +leave: + mdb_txn_abort(txn); + return rc; +} + +int +mdb_env_copy(MDB_env *env, const char *path) +{ + int rc, len; + char *lpath; + HANDLE newfd = INVALID_HANDLE_VALUE; + + if (env->me_flags & MDB_NOSUBDIR) { + lpath = (char *)path; + } else { + len = strlen(path); + len += sizeof(DATANAME); + lpath = malloc(len); + if (!lpath) + return ENOMEM; + sprintf(lpath, "%s" DATANAME, path); + } + + // The destination path must exist, but the destination file must not. + // We don't want the OS to cache the writes, since the source data is + // already in the OS cache. +#ifdef _WIN32 + newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW, + FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL); +#else + newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666); +#endif + if (newfd == INVALID_HANDLE_VALUE) { + rc = ErrCode(); + goto leave; + } + +#ifdef O_DIRECT + // Set O_DIRECT if the file system supports it + if ((rc = fcntl(newfd, F_GETFL)) != -1) + (void) fcntl(newfd, F_SETFL, rc | O_DIRECT); +#endif +#ifdef F_NOCACHE // __APPLE__ + rc = fcntl(newfd, F_NOCACHE, 1); + if (rc) { + rc = ErrCode(); + goto leave; + } +#endif + + rc = mdb_env_copyfd(env, newfd); + +leave: + if (!(env->me_flags & MDB_NOSUBDIR)) + free(lpath); + if (newfd != INVALID_HANDLE_VALUE) + if (close(newfd) < 0 && rc == MDB_SUCCESS) + rc = ErrCode(); + + return rc; + */ + return nil +} + +func (db *db) Close() { + /* + MDB_page *dp; + + if (env == NULL) + return; + + VGMEMP_DESTROY(env); + while ((dp = env->me_dpages) != NULL) { + VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next)); + env->me_dpages = dp->mp_next; + free(dp); + } + + mdb_env_close0(env, 0); + free(env); + */ +} + +// 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. +func (db *db) LeafSize(key []byte, data []byte) int { + /* + size_t sz; + + sz = LEAFSIZE(key, data); + if (sz > env->me_nodemax) { + // put on overflow page + sz -= data->mv_size - sizeof(pgno_t); + } + + return EVEN(sz + sizeof(indx_t)); + */ + return 0 +} + +// 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. +func (db *db) BranchSize(key []byte) int { + /* + size_t sz; + + sz = INDXSIZE(key); + if (sz > env->me_nodemax) { + // put on overflow page + // not implemented + // sz -= key->size - sizeof(pgno_t); + } + + return sz + sizeof(indx_t); + */ + return 0 +} + +func (db *db) SetFlags(flag int, onoff bool) error { + /* + if ((flag & CHANGEABLE) != flag) + return EINVAL; + if (onoff) + env->me_flags |= flag; + else + env->me_flags &= ~flag; + return MDB_SUCCESS; + */ + return nil +} + +func (db *db) Flags() int { + return db.flags +} + + +func (db *db) Stat() *Stat + /* + int toggle; + + if (env == NULL || arg == NULL) + return EINVAL; + + toggle = mdb_env_pick_meta(env); + stat := &Stat{} + stat->ms_psize = env->me_psize; + stat->ms_depth = db->md_depth; + stat->ms_branch_pages = db->md_branch_pages; + stat->ms_leaf_pages = db->md_leaf_pages; + stat->ms_overflow_pages = db->md_overflow_pages; + stat->ms_entries = db->md_entries; + + //return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], stat); + return stat + */ +} + +func (db *db) Info() *Info { + /* + int toggle; + + if (env == NULL || arg == NULL) + return EINVAL; + + toggle = mdb_env_pick_meta(env); + arg->me_mapaddr = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : 0; + arg->me_mapsize = env->me_mapsize; + arg->me_maxreaders = env->me_maxreaders; + + // me_numreaders may be zero if this process never used any readers. Use + // the shared numreader count if it exists. + arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders; + + arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg; + arg->me_last_txnid = env->me_metas[toggle]->mm_txnid; + return MDB_SUCCESS; + */ + return nil +} + +// TODO: Move to bucket.go +func (db *db) CloseBucket(b Bucket) { + /* + char *ptr; + if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs) + 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; + env->me_dbflags[dbi] = 0; + free(ptr); + */ +} + +//int mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx) +func (db *db) getReaderList() error { + /* + unsigned int i, rdrs; + MDB_reader *mr; + char buf[64]; + int rc = 0, first = 1; + + if (!env || !func) + return -1; + if (!env->me_txns) { + return func("(no reader locks)\n", ctx); + } + rdrs = env->me_txns->mti_numreaders; + mr = env->me_txns->mti_readers; + for (i=0; i<rdrs; i++) { + if (mr[i].mr_pid) { + txnid_t txnid = mr[i].mr_txnid; + sprintf(buf, txnid == (txnid_t)-1 ? + "%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n", + (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid); + if (first) { + first = 0; + rc = func(" pid thread txnid\n", ctx); + if (rc < 0) + break; + } + rc = func(buf, ctx); + if (rc < 0) + break; + } + } + if (first) { + rc = func("(no active readers)\n", ctx); + } + return rc; + */ + return nil +} + +// (bool return is whether reader is dead) +func (db *db) checkReaders() (bool, error) { + /* + unsigned int i, j, rdrs; + MDB_reader *mr; + MDB_PID_T *pids, pid; + int count = 0; + + if (!env) + return EINVAL; + if (dead) + *dead = 0; + if (!env->me_txns) + return MDB_SUCCESS; + rdrs = env->me_txns->mti_numreaders; + pids = malloc((rdrs+1) * sizeof(MDB_PID_T)); + if (!pids) + return ENOMEM; + pids[0] = 0; + mr = env->me_txns->mti_readers; + for (i=0; i<rdrs; i++) { + if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) { + pid = mr[i].mr_pid; + if (mdb_pid_insert(pids, pid) == 0) { + if (!mdb_reader_pid(env, Pidcheck, pid)) { + LOCK_MUTEX_R(env); + // Recheck, a new process may have reused pid + if (!mdb_reader_pid(env, Pidcheck, pid)) { + for (j=i; j<rdrs; j++) + if (mr[j].mr_pid == pid) { + DPRINTF(("clear stale reader pid %u txn %"Z"d", + (unsigned) pid, mr[j].mr_txnid)); + mr[j].mr_pid = 0; + count++; + } + } + UNLOCK_MUTEX_R(env); + } + } + } + } + free(pids); + if (dead) + *dead = count; + return MDB_SUCCESS; + */ + return false, nil +} |