+ /*
+ Trivial Database 2: fetch, store and misc routines.
+ Copyright (C) Rusty Russell 2010
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
#include "private.h"
-#include <ccan/tdb2/tdb2.h>
-#include <ccan/hash/hash.h>
-#include <ccan/likely/likely.h>
-#include <assert.h>
-
-/* The null return. */
-struct tdb_data tdb_null = { .dptr = NULL, .dsize = 0 };
-
-/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
-static struct tdb_context *tdbs = NULL;
-
-PRINTF_ATTRIBUTE(4, 5) static void
-null_log_fn(struct tdb_context *tdb,
- enum tdb_debug_level level, void *priv,
- const char *fmt, ...)
+#include <ccan/asprintf/asprintf.h>
+#include <stdarg.h>
+
+static enum TDB_ERROR update_rec_hdr(struct tdb_context *tdb,
+ tdb_off_t off,
+ tdb_len_t keylen,
+ tdb_len_t datalen,
+ struct tdb_used_record *rec,
+ uint64_t h)
{
+ uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
+ enum TDB_ERROR ecode;
+
+ ecode = set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
+ keylen + dataroom, h);
+ if (ecode == TDB_SUCCESS) {
+ ecode = tdb_write_convert(tdb, off, rec, sizeof(*rec));
+ }
+ return ecode;
}
-/* We do a lot of work assuming our copy of the header volatile area
- * is uptodate, and usually it is. However, once we grab a lock, we have to
- * re-check it. */
-bool update_header(struct tdb_context *tdb)
+static enum TDB_ERROR replace_data(struct tdb_context *tdb,
+ struct hash_info *h,
+ struct tdb_data key, struct tdb_data dbuf,
+ tdb_off_t old_off, tdb_len_t old_room,
+ bool growing)
{
- struct tdb_header_volatile pad, *v;
+ tdb_off_t new_off;
+ enum TDB_ERROR ecode;
- if (tdb->header_uptodate) {
- tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv,
- "warning: header uptodate already\n");
+ /* Allocate a new record. */
+ new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
+ growing);
+ if (TDB_OFF_IS_ERR(new_off)) {
+ return new_off;
}
- /* We could get a partial update if we're not holding any locks. */
- assert(tdb_has_locks(tdb));
+ /* We didn't like the existing one: remove it. */
+ if (old_off) {
+ tdb->stats.frees++;
+ ecode = add_free_record(tdb, old_off,
+ sizeof(struct tdb_used_record)
+ + key.dsize + old_room,
+ TDB_LOCK_WAIT, true);
+ if (ecode == TDB_SUCCESS)
+ ecode = replace_in_hash(tdb, h, new_off);
+ } else {
+ ecode = add_to_hash(tdb, h, new_off);
+ }
+ if (ecode != TDB_SUCCESS) {
+ return ecode;
+ }
- v = tdb_get(tdb, offsetof(struct tdb_header, v), &pad, sizeof(*v));
- if (!v) {
- /* On failure, imply we updated header so they retry. */
- return true;
+ new_off += sizeof(struct tdb_used_record);
+ ecode = tdb->methods->twrite(tdb, new_off, key.dptr, key.dsize);
+ if (ecode != TDB_SUCCESS) {
+ return ecode;
}
- tdb->header_uptodate = true;
- if (likely(memcmp(&tdb->header.v, v, sizeof(*v)) == 0)) {
- return false;
+
+ new_off += key.dsize;
+ ecode = tdb->methods->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize);
+ if (ecode != TDB_SUCCESS) {
+ return ecode;
}
- tdb->header.v = *v;
- return true;
-}
-static uint64_t jenkins_hash(const void *key, size_t length, uint64_t seed,
- void *arg)
-{
- return hash64_any(key, length, seed);
-}
+ if (tdb->flags & TDB_SEQNUM)
+ tdb_inc_seqnum(tdb);
-uint64_t tdb_hash(struct tdb_context *tdb, const void *ptr, size_t len)
-{
- return tdb->khash(ptr, len, tdb->header.hash_seed, tdb->hash_priv);
+ return TDB_SUCCESS;
}
-static bool tdb_already_open(dev_t device, ino_t ino)
+static enum TDB_ERROR update_data(struct tdb_context *tdb,
+ tdb_off_t off,
+ struct tdb_data dbuf,
+ tdb_len_t extra)
{
- struct tdb_context *i;
-
- for (i = tdbs; i; i = i->next) {
- if (i->device == device && i->inode == ino) {
- return true;
- }
+ enum TDB_ERROR ecode;
+
+ ecode = tdb->methods->twrite(tdb, off, dbuf.dptr, dbuf.dsize);
+ if (ecode == TDB_SUCCESS && extra) {
+ /* Put a zero in; future versions may append other data. */
+ ecode = tdb->methods->twrite(tdb, off + dbuf.dsize, "", 1);
}
+ if (tdb->flags & TDB_SEQNUM)
+ tdb_inc_seqnum(tdb);
- return false;
+ return ecode;
}
-static uint64_t random_number(struct tdb_context *tdb)
+enum TDB_ERROR tdb_store(struct tdb_context *tdb,
+ struct tdb_data key, struct tdb_data dbuf, int flag)
{
- int fd;
- uint64_t ret = 0;
- struct timeval now;
-
- fd = open("/dev/urandom", O_RDONLY);
- if (fd >= 0) {
- if (read(fd, &ret, sizeof(ret)) == sizeof(ret)) {
- tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
- "tdb_open: random from /dev/urandom\n");
- close(fd);
- return ret;
- }
- close(fd);
+ struct hash_info h;
+ tdb_off_t off;
+ tdb_len_t old_room = 0;
+ struct tdb_used_record rec;
+ enum TDB_ERROR ecode;
+
+ off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
+ if (TDB_OFF_IS_ERR(off)) {
+ return tdb->last_error = off;
}
- /* FIXME: Untested! Based on Wikipedia protocol description! */
- fd = open("/dev/egd-pool", O_RDWR);
- if (fd >= 0) {
- /* Command is 1, next byte is size we want to read. */
- char cmd[2] = { 1, sizeof(uint64_t) };
- if (write(fd, cmd, sizeof(cmd)) == sizeof(cmd)) {
- char reply[1 + sizeof(uint64_t)];
- int r = read(fd, reply, sizeof(reply));
- if (r > 1) {
- tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
- "tdb_open: %u random bytes from"
- " /dev/egd-pool\n", r-1);
- /* Copy at least some bytes. */
- memcpy(&ret, reply+1, r - 1);
- if (reply[0] == sizeof(uint64_t)
- && r == sizeof(reply)) {
- close(fd);
- return ret;
+
+ /* Now we have lock on this hash bucket. */
+ if (flag == TDB_INSERT) {
+ if (off) {
+ ecode = TDB_ERR_EXISTS;
+ goto out;
+ }
+ } else {
+ if (off) {
+ old_room = rec_data_length(&rec)
+ + rec_extra_padding(&rec);
+ if (old_room >= dbuf.dsize) {
+ /* Can modify in-place. Easy! */
+ ecode = update_rec_hdr(tdb, off,
+ key.dsize, dbuf.dsize,
+ &rec, h.h);
+ if (ecode != TDB_SUCCESS) {
+ goto out;
+ }
+ ecode = update_data(tdb,
+ off + sizeof(rec)
+ + key.dsize, dbuf,
+ old_room - dbuf.dsize);
+ if (ecode != TDB_SUCCESS) {
+ goto out;
}
+ tdb_unlock_hashes(tdb, h.hlock_start,
+ h.hlock_range, F_WRLCK);
+ return tdb->last_error = TDB_SUCCESS;
+ }
+ } else {
+ if (flag == TDB_MODIFY) {
+ /* if the record doesn't exist and we
+ are in TDB_MODIFY mode then we should fail
+ the store */
+ ecode = TDB_ERR_NOEXIST;
+ goto out;
}
}
- close(fd);
- }
-
- /* Fallback: pid and time. */
- gettimeofday(&now, NULL);
- ret = getpid() * 100132289ULL + now.tv_sec * 1000000ULL + now.tv_usec;
- tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
- "tdb_open: random from getpid and time\n");
- return ret;
-}
-
-struct new_database {
- struct tdb_header hdr;
- struct tdb_used_record hrec;
- tdb_off_t hash[1ULL << INITIAL_HASH_BITS];
- struct tdb_used_record frec;
- tdb_off_t free[INITIAL_FREE_BUCKETS + 1]; /* One overflow bucket */
-};
-
-/* initialise a new database */
-static int tdb_new_database(struct tdb_context *tdb)
-{
- /* We make it up in memory, then write it out if not internal */
- struct new_database newdb;
-
- /* Fill in the header */
- newdb.hdr.version = TDB_VERSION;
- newdb.hdr.hash_seed = random_number(tdb);
- newdb.hdr.hash_test = TDB_HASH_MAGIC;
- newdb.hdr.hash_test = tdb->khash(&newdb.hdr.hash_test,
- sizeof(newdb.hdr.hash_test),
- newdb.hdr.hash_seed,
- tdb->hash_priv);
-
- newdb.hdr.v.generation = 0;
-
- /* Free array has 1 zone, 10 buckets. All buckets empty. */
- newdb.hdr.v.num_zones = 1;
- newdb.hdr.v.zone_bits = INITIAL_ZONE_BITS;
- newdb.hdr.v.free_buckets = INITIAL_FREE_BUCKETS;
- newdb.hdr.v.free_off = offsetof(struct new_database, free);
- set_header(tdb, &newdb.frec, 0,
- sizeof(newdb.free), sizeof(newdb.free), 0);
- memset(newdb.free, 0, sizeof(newdb.free));
-
- /* Initial hashes are empty. */
- newdb.hdr.v.hash_bits = INITIAL_HASH_BITS;
- newdb.hdr.v.hash_off = offsetof(struct new_database, hash);
- set_header(tdb, &newdb.hrec, 0,
- sizeof(newdb.hash), sizeof(newdb.hash), 0);
- memset(newdb.hash, 0, sizeof(newdb.hash));
-
- if (tdb->flags & TDB_INTERNAL) {
- tdb->map_size = sizeof(newdb);
- tdb->map_ptr = malloc(tdb->map_size);
- if (!tdb->map_ptr) {
- tdb->ecode = TDB_ERR_OOM;
- return -1;
- }
- memcpy(tdb->map_ptr, &newdb, tdb->map_size);
- tdb->header = newdb.hdr;
- /* Convert the `ondisk' version if asked. */
- tdb_convert(tdb, tdb->map_ptr, sizeof(newdb));
- return 0;
}
- if (lseek(tdb->fd, 0, SEEK_SET) == -1)
- return -1;
-
- if (ftruncate(tdb->fd, 0) == -1)
- return -1;
-
- /* This creates an endian-converted header, as if read from disk */
- tdb->header = newdb.hdr;
- tdb_convert(tdb, &tdb->header, sizeof(tdb->header));
- /* Don't endian-convert the magic food! */
- memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
- strcpy(newdb.hdr.magic_food, TDB_MAGIC_FOOD);
-
- if (!tdb_pwrite_all(tdb->fd, &newdb, sizeof(newdb), 0)) {
- tdb->ecode = TDB_ERR_IO;
- return -1;
- }
- return 0;
+ /* If we didn't use the old record, this implies we're growing. */
+ ecode = replace_data(tdb, &h, key, dbuf, off, old_room, off);
+out:
+ tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
+ return tdb->last_error = ecode;
}
-struct tdb_context *tdb_open(const char *name, int tdb_flags,
- int open_flags, mode_t mode,
- union tdb_attribute *attr)
+enum TDB_ERROR tdb_append(struct tdb_context *tdb,
+ struct tdb_data key, struct tdb_data dbuf)
{
- struct tdb_context *tdb;
- struct stat st;
- int save_errno;
- uint64_t hash_test;
- unsigned v;
-
- if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
- /* Can't log this */
- errno = ENOMEM;
- goto fail;
- }
- tdb->fd = -1;
- tdb->name = NULL;
- tdb->map_ptr = NULL;
- tdb->flags = tdb_flags;
- tdb->log = null_log_fn;
- tdb->log_priv = NULL;
- tdb->khash = jenkins_hash;
- tdb->hash_priv = NULL;
-
- /* FIXME */
- if (attr) {
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: attributes not yet supported\n");
- errno = EINVAL;
- goto fail;
- }
+ struct hash_info h;
+ tdb_off_t off;
+ struct tdb_used_record rec;
+ tdb_len_t old_room = 0, old_dlen;
+ unsigned char *newdata;
+ struct tdb_data new_dbuf;
+ enum TDB_ERROR ecode;
- if ((open_flags & O_ACCMODE) == O_WRONLY) {
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: can't open tdb %s write-only\n", name);
- errno = EINVAL;
- goto fail;
+ off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
+ if (TDB_OFF_IS_ERR(off)) {
+ return tdb->last_error = off;
}
- if ((open_flags & O_ACCMODE) == O_RDONLY) {
- tdb->read_only = 1;
- /* read only databases don't do locking */
- tdb->flags |= TDB_NOLOCK;
- }
+ if (off) {
+ old_dlen = rec_data_length(&rec);
+ old_room = old_dlen + rec_extra_padding(&rec);
+
+ /* Fast path: can append in place. */
+ if (rec_extra_padding(&rec) >= dbuf.dsize) {
+ ecode = update_rec_hdr(tdb, off, key.dsize,
+ old_dlen + dbuf.dsize, &rec,
+ h.h);
+ if (ecode != TDB_SUCCESS) {
+ goto out;
+ }
- /* internal databases don't mmap or lock */
- if (tdb->flags & TDB_INTERNAL) {
- tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
- if (tdb_new_database(tdb) != 0) {
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: tdb_new_database failed!");
- goto fail;
+ off += sizeof(rec) + key.dsize + old_dlen;
+ ecode = update_data(tdb, off, dbuf,
+ rec_extra_padding(&rec));
+ goto out;
}
- TEST_IT(tdb->flags & TDB_CONVERT);
- goto internal;
- }
-
- if ((tdb->fd = open(name, open_flags, mode)) == -1) {
- tdb->log(tdb, TDB_DEBUG_WARNING, tdb->log_priv,
- "tdb_open: could not open file %s: %s\n",
- name, strerror(errno));
- goto fail; /* errno set by open(2) */
- }
- /* on exec, don't inherit the fd */
- v = fcntl(tdb->fd, F_GETFD, 0);
- fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
-
- /* ensure there is only one process initialising at once */
- if (tdb_lock_open(tdb) == -1) {
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: failed to get open lock on %s: %s\n",
- name, strerror(errno));
- goto fail; /* errno set by tdb_brlock */
- }
-
- errno = 0;
- if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
- || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
- if (!(open_flags & O_CREAT) || tdb_new_database(tdb) == -1) {
- if (errno == 0) {
- errno = EIO; /* ie bad format or something */
- }
- goto fail;
+ /* Slow path. */
+ newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
+ if (!newdata) {
+ ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+ "tdb_append:"
+ " failed to allocate %zu bytes",
+ (size_t)(key.dsize + old_dlen
+ + dbuf.dsize));
+ goto out;
}
- } else if (tdb->header.version != TDB_VERSION) {
- if (tdb->header.version == bswap_64(TDB_VERSION))
- tdb->flags |= TDB_CONVERT;
- else {
- /* wrong version */
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: %s is unknown version 0x%llx\n",
- name, (long long)tdb->header.version);
- errno = EIO;
- goto fail;
+ ecode = tdb->methods->tread(tdb, off + sizeof(rec) + key.dsize,
+ newdata, old_dlen);
+ if (ecode != TDB_SUCCESS) {
+ goto out_free_newdata;
}
+ memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
+ new_dbuf.dptr = newdata;
+ new_dbuf.dsize = old_dlen + dbuf.dsize;
+ } else {
+ newdata = NULL;
+ new_dbuf = dbuf;
}
- tdb_convert(tdb, &tdb->header, sizeof(tdb->header));
- hash_test = TDB_HASH_MAGIC;
- hash_test = tdb->khash(&hash_test, sizeof(hash_test),
- tdb->header.hash_seed, tdb->hash_priv);
- if (tdb->header.hash_test != hash_test) {
- /* wrong hash variant */
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: %s uses a different hash function\n",
- name);
- errno = EIO;
- goto fail;
- }
-
- if (fstat(tdb->fd, &st) == -1)
- goto fail;
-
- /* Is it already in the open list? If so, fail. */
- if (tdb_already_open(st.st_dev, st.st_ino)) {
- /* FIXME */
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: %s (%d,%d) is already open in this process\n",
- name, (int)st.st_dev, (int)st.st_ino);
- errno = EBUSY;
- goto fail;
- }
-
- tdb->name = strdup(name);
- if (!tdb->name) {
- errno = ENOMEM;
- goto fail;
- }
-
- tdb->map_size = st.st_size;
- tdb->device = st.st_dev;
- tdb->inode = st.st_ino;
- tdb_io_init(tdb);
- tdb_mmap(tdb);
-
- internal:
- /* Internal (memory-only) databases skip all the code above to
- * do with disk files, and resume here by releasing their
- * open lock and hooking into the active list. */
- tdb_unlock_open(tdb);
- tdb->last_zone = random_free_zone(tdb);
- tdb->next = tdbs;
- tdbs = tdb;
- return tdb;
-
- fail:
- save_errno = errno;
-
- if (!tdb)
- return NULL;
-
-#ifdef TDB_TRACE
- close(tdb->tracefd);
-#endif
- if (tdb->map_ptr) {
- if (tdb->flags & TDB_INTERNAL) {
- free(tdb->map_ptr);
- } else
- tdb_munmap(tdb);
- }
- free((char *)tdb->name);
- if (tdb->fd != -1)
- if (close(tdb->fd) != 0)
- tdb->log(tdb, TDB_DEBUG_ERROR, tdb->log_priv,
- "tdb_open: failed to close tdb->fd"
- " on error!\n");
- free(tdb);
- errno = save_errno;
- return NULL;
-}
-
-static int tdb_key_compare(TDB_DATA key, TDB_DATA data, void *private_data)
-{
- return memcmp(data.dptr, key.dptr, data.dsize) == 0;
-}
+ /* If they're using tdb_append(), it implies they're growing record. */
+ ecode = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
-static void unlock_lists(struct tdb_context *tdb,
- uint64_t start, uint64_t end, int ltype)
-{
- do {
- tdb_unlock_list(tdb, start, ltype);
- start = (start + ((1ULL << tdb->header.v.hash_bits) - 1))
- & ((1ULL << tdb->header.v.hash_bits) - 1);
- } while (start != end);
+out_free_newdata:
+ free(newdata);
+out:
+ tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
+ return tdb->last_error = ecode;
}
-/* FIXME: Return header copy? */
-/* Returns -1 or offset of entry (0 if not found).
- * Locks hash entried from *start to *end (where the entry was found). */
-static tdb_off_t find_bucket_and_lock(struct tdb_context *tdb,
- const struct tdb_data *key,
- uint64_t hash,
- uint64_t *start,
- uint64_t *end,
- uint64_t *room,
- int ltype)
+enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
+ struct tdb_data *data)
{
- uint64_t hextra;
tdb_off_t off;
+ struct tdb_used_record rec;
+ struct hash_info h;
+ enum TDB_ERROR ecode;
- /* hash_bits might be out of date... */
-again:
- *start = *end = hash & ((1ULL << tdb->header.v.hash_bits) - 1);
- hextra = hash >> tdb->header.v.hash_bits;
-
- /* FIXME: can we avoid locks for some fast paths? */
- if (tdb_lock_list(tdb, *end, ltype, TDB_LOCK_WAIT) == -1)
- return TDB_OFF_ERR;
-
- /* We only need to check this for first lock. */
- if (unlikely(update_header(tdb))) {
- tdb_unlock_list(tdb, *end, ltype);
- goto again;
+ off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
+ if (TDB_OFF_IS_ERR(off)) {
+ return tdb->last_error = off;
}
- while ((off = tdb_read_off(tdb, tdb->header.v.hash_off
- + *end * sizeof(tdb_off_t)))
- != TDB_OFF_ERR) {
- struct tdb_used_record pad, *r;
- uint64_t keylen, next;
-
- /* Didn't find it? */
- if (!off)
- return 0;
-
-#if 0 /* FIXME: Check other bits. */
- unsigned int bits, bitmask, hoffextra;
- /* Bottom three bits show how many extra hash bits. */
- bits = (off & ((1 << TDB_EXTRA_HASHBITS_NUM) - 1)) + 1;
- bitmask = (1 << bits)-1;
- hoffextra = ((off >> TDB_EXTRA_HASHBITS_NUM) & bitmask);
- if ((hextra & bitmask) != hoffextra)
- goto lock_next;
-#endif
-
- r = tdb_get(tdb, off, &pad, sizeof(*r));
- if (!r)
- goto unlock_err;
-
- if (rec_magic(r) != TDB_MAGIC) {
- tdb->ecode = TDB_ERR_CORRUPT;
- tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
- "find_bucket_and_lock: bad magic 0x%llx"
- " at offset %llu!\n",
- (long long)rec_magic(r), (long long)off);
- goto unlock_err;
- }
-
- /* FIXME: check extra bits in header! */
- keylen = rec_key_length(r);
- if (keylen != key->dsize)
- goto lock_next;
-
- switch (tdb_parse_data(tdb, *key, off + sizeof(*r), key->dsize,
- tdb_key_compare, NULL)) {
- case 1:
- /* Match! */
- *room = rec_data_length(r) + rec_extra_padding(r);
- return off >> TDB_EXTRA_HASHBITS_NUM;
- case 0:
- break;
- default:
- goto unlock_err;
- }
-
- lock_next:
- /* Lock next bucket. */
- /* FIXME: We can deadlock if this wraps! */
- next = (*end + 1) & ((1ULL << tdb->header.v.hash_bits) - 1);
- if (next == *start) {
- tdb->ecode = TDB_ERR_CORRUPT;
- tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
- "find_bucket_and_lock: full hash table!\n");
- goto unlock_err;
- }
- if (tdb_lock_list(tdb, next, ltype, TDB_LOCK_WAIT) == -1)
- goto unlock_err;
- *end = next;
+ if (!off) {
+ ecode = TDB_ERR_NOEXIST;
+ } else {
+ data->dsize = rec_data_length(&rec);
+ data->dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
+ data->dsize);
+ if (TDB_PTR_IS_ERR(data->dptr)) {
+ ecode = TDB_PTR_ERR(data->dptr);
+ } else
+ ecode = TDB_SUCCESS;
}
-unlock_err:
- TEST_IT(*end < *start);
- unlock_lists(tdb, *start, *end, ltype);
- return TDB_OFF_ERR;
+ tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
+ return tdb->last_error = ecode;
}
-static int update_rec_hdr(struct tdb_context *tdb,
- tdb_off_t off,
- tdb_len_t keylen,
- tdb_len_t datalen,
- tdb_len_t room,
- uint64_t h)
+bool tdb_exists(struct tdb_context *tdb, TDB_DATA key)
{
+ tdb_off_t off;
struct tdb_used_record rec;
+ struct hash_info h;
- if (set_header(tdb, &rec, keylen, datalen, room - datalen, h))
- return -1;
+ off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
+ if (TDB_OFF_IS_ERR(off)) {
+ tdb->last_error = off;
+ return false;
+ }
+ tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
- return tdb_write_convert(tdb, off, &rec, sizeof(rec));
+ tdb->last_error = TDB_SUCCESS;
+ return off ? true : false;
}
-/* If we fail, others will try after us. */
-static void enlarge_hash(struct tdb_context *tdb)
+enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
{
- tdb_off_t newoff, i;
- uint64_t h, num = 1ULL << tdb->header.v.hash_bits;
- struct tdb_used_record pad, *r;
-
- /* FIXME: We should do this without holding locks throughout. */
- if (tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false) == -1)
- return;
+ tdb_off_t off;
+ struct tdb_used_record rec;
+ struct hash_info h;
+ enum TDB_ERROR ecode;
- if (unlikely(update_header(tdb))) {
- /* Someone else enlarged for us? Nothing to do. */
- if ((1ULL << tdb->header.v.hash_bits) != num)
- goto unlock;
+ off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
+ if (TDB_OFF_IS_ERR(off)) {
+ return tdb->last_error = off;
}
- newoff = alloc(tdb, 0, num * 2, 0, false);
- if (unlikely(newoff == TDB_OFF_ERR))
+ if (!off) {
+ ecode = TDB_ERR_NOEXIST;
goto unlock;
- if (unlikely(newoff == 0)) {
- if (tdb_expand(tdb, 0, num * 2, false) == -1)
- goto unlock;
- newoff = alloc(tdb, 0, num * 2, 0, false);
- if (newoff == TDB_OFF_ERR || newoff == 0)
- goto unlock;
}
- /* FIXME: If the space before is empty, we know this is in its ideal
- * location. We can steal a bit from the pointer to avoid rehash. */
- for (i = tdb_find_nonzero_off(tdb, tdb->header.v.hash_off, num);
- i < num;
- i += tdb_find_nonzero_off(tdb, tdb->header.v.hash_off
- + i*sizeof(tdb_off_t), num - i)) {
- tdb_off_t off;
- off = tdb_read_off(tdb, tdb->header.v.hash_off
- + i*sizeof(tdb_off_t));
- if (unlikely(off == TDB_OFF_ERR))
- goto unlock;
- if (unlikely(!off)) {
- tdb->ecode = TDB_ERR_CORRUPT;
- tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
- "find_bucket_and_lock: zero hash bucket!\n");
- goto unlock;
- }
- h = hash_record(tdb, off);
- /* FIXME: Encode extra hash bits! */
- if (tdb_write_off(tdb, newoff
- + (h & ((num * 2) - 1)) * sizeof(uint64_t),
- off) == -1)
- goto unlock;
+ ecode = delete_from_hash(tdb, &h);
+ if (ecode != TDB_SUCCESS) {
+ goto unlock;
}
- /* Free up old hash. */
- r = tdb_get(tdb, tdb->header.v.hash_off, &pad, sizeof(*r));
- if (!r)
- goto unlock;
- add_free_record(tdb, tdb->header.v.hash_off,
- rec_data_length(r) + rec_extra_padding(r));
-
- /* Now we write the modified header. */
- tdb->header.v.generation++;
- tdb->header.v.hash_bits++;
- tdb->header.v.hash_off = newoff;
- tdb_write_convert(tdb, offsetof(struct tdb_header, v),
- &tdb->header.v, sizeof(tdb->header.v));
+ /* Free the deleted entry. */
+ tdb->stats.frees++;
+ ecode = add_free_record(tdb, off,
+ sizeof(struct tdb_used_record)
+ + rec_key_length(&rec)
+ + rec_data_length(&rec)
+ + rec_extra_padding(&rec),
+ TDB_LOCK_WAIT, true);
+
+ if (tdb->flags & TDB_SEQNUM)
+ tdb_inc_seqnum(tdb);
+
unlock:
- tdb_allrecord_unlock(tdb, F_WRLCK);
+ tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
+ return tdb->last_error = ecode;
}
-int tdb_store(struct tdb_context *tdb,
- struct tdb_data key, struct tdb_data dbuf, int flag)
+unsigned int tdb_get_flags(struct tdb_context *tdb)
{
- tdb_off_t new_off, off, start, end, room;
- uint64_t h;
- bool growing = false;
-
- h = tdb_hash(tdb, key.dptr, key.dsize);
- off = find_bucket_and_lock(tdb, &key, h, &start, &end, &room, F_WRLCK);
- if (off == TDB_OFF_ERR)
- return -1;
-
- /* Now we have lock on this hash bucket. */
- if (flag == TDB_INSERT) {
- if (off) {
- tdb->ecode = TDB_ERR_EXISTS;
- goto fail;
- }
- } else {
- if (off) {
- if (room >= key.dsize + dbuf.dsize) {
- new_off = off;
- if (update_rec_hdr(tdb, off,
- key.dsize, dbuf.dsize,
- room, h))
- goto fail;
- goto write;
- }
- /* FIXME: See if right record is free? */
- /* Hint to allocator that we've realloced. */
- growing = true;
- } else {
- if (flag == TDB_MODIFY) {
- /* if the record doesn't exist and we
- are in TDB_MODIFY mode then we should fail
- the store */
- tdb->ecode = TDB_ERR_NOEXIST;
- goto fail;
- }
- }
- }
+ return tdb->flags;
+}
- /* Allocate a new record. */
- new_off = alloc(tdb, key.dsize, dbuf.dsize, h, growing);
- if (new_off == 0) {
- unlock_lists(tdb, start, end, F_WRLCK);
- /* Expand, then try again... */
- if (tdb_expand(tdb, key.dsize, dbuf.dsize, growing) == -1)
- return -1;
- return tdb_store(tdb, key, dbuf, flag);
+void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
+{
+ if (tdb->flags & TDB_INTERNAL) {
+ tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+ TDB_LOG_USE_ERROR,
+ "tdb_add_flag: internal db");
+ return;
}
-
- /* We didn't like the existing one: remove it. */
- if (off) {
- add_free_record(tdb, off, sizeof(struct tdb_used_record)
- + key.dsize + room);
+ switch (flag) {
+ case TDB_NOLOCK:
+ tdb->flags |= TDB_NOLOCK;
+ break;
+ case TDB_NOMMAP:
+ tdb->flags |= TDB_NOMMAP;
+ tdb_munmap(tdb->file);
+ break;
+ case TDB_NOSYNC:
+ tdb->flags |= TDB_NOSYNC;
+ break;
+ case TDB_SEQNUM:
+ tdb->flags |= TDB_SEQNUM;
+ break;
+ case TDB_ALLOW_NESTING:
+ tdb->flags |= TDB_ALLOW_NESTING;
+ break;
+ default:
+ tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+ TDB_LOG_USE_ERROR,
+ "tdb_add_flag: Unknown flag %u",
+ flag);
}
-
-write:
- off = tdb->header.v.hash_off + end * sizeof(tdb_off_t);
- /* FIXME: Encode extra hash bits! */
- if (tdb_write_off(tdb, off, new_off) == -1)
- goto fail;
-
- off = new_off + sizeof(struct tdb_used_record);
- if (tdb->methods->write(tdb, off, key.dptr, key.dsize) == -1)
- goto fail;
- off += key.dsize;
- if (tdb->methods->write(tdb, off, dbuf.dptr, dbuf.dsize) == -1)
- goto fail;
-
- /* FIXME: tdb_increment_seqnum(tdb); */
- unlock_lists(tdb, start, end, F_WRLCK);
-
- /* By simple trial and error, this roughly approximates a 60%
- * full measure. */
- if (unlikely(end - start > 4 * tdb->header.v.hash_bits - 32))
- enlarge_hash(tdb);
-
- return 0;
-
-fail:
- unlock_lists(tdb, start, end, F_WRLCK);
- return -1;
}
-struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key)
+void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
{
- tdb_off_t off, start, end, room;
- uint64_t h;
- struct tdb_used_record pad, *r;
- struct tdb_data ret;
-
- h = tdb_hash(tdb, key.dptr, key.dsize);
- off = find_bucket_and_lock(tdb, &key, h, &start, &end, &room, F_RDLCK);
- if (off == TDB_OFF_ERR)
- return tdb_null;
-
- if (!off) {
- unlock_lists(tdb, start, end, F_RDLCK);
- tdb->ecode = TDB_SUCCESS;
- return tdb_null;
+ if (tdb->flags & TDB_INTERNAL) {
+ tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+ TDB_LOG_USE_ERROR,
+ "tdb_remove_flag: internal db");
+ return;
}
-
- r = tdb_get(tdb, off, &pad, sizeof(*r));
- if (!r) {
- unlock_lists(tdb, start, end, F_RDLCK);
- return tdb_null;
+ switch (flag) {
+ case TDB_NOLOCK:
+ tdb->flags &= ~TDB_NOLOCK;
+ break;
+ case TDB_NOMMAP:
+ tdb->flags &= ~TDB_NOMMAP;
+ tdb_mmap(tdb);
+ break;
+ case TDB_NOSYNC:
+ tdb->flags &= ~TDB_NOSYNC;
+ break;
+ case TDB_SEQNUM:
+ tdb->flags &= ~TDB_SEQNUM;
+ break;
+ case TDB_ALLOW_NESTING:
+ tdb->flags &= ~TDB_ALLOW_NESTING;
+ break;
+ default:
+ tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
+ TDB_LOG_USE_ERROR,
+ "tdb_remove_flag: Unknown flag %u",
+ flag);
}
-
- ret.dsize = rec_data_length(r);
- ret.dptr = tdb_alloc_read(tdb, off + sizeof(*r) + key.dsize,
- ret.dsize);
- unlock_lists(tdb, start, end, F_RDLCK);
- return ret;
}
-static int hash_add(struct tdb_context *tdb, uint64_t h, tdb_off_t off)
+const char *tdb_errorstr(enum TDB_ERROR ecode)
{
- tdb_off_t i, hoff, len, num;
-
- i = (h & ((1ULL << tdb->header.v.hash_bits) - 1));
- hoff = tdb->header.v.hash_off + i * sizeof(tdb_off_t);
- len = (1ULL << tdb->header.v.hash_bits) - i;
-
- /* Look for next space. */
- num = tdb_find_zero_off(tdb, hoff, len);
- if (unlikely(num == len)) {
- hoff = tdb->header.v.hash_off;
- len = (1ULL << tdb->header.v.hash_bits);
- num = tdb_find_zero_off(tdb, hoff, len);
- if (i == len)
- return -1;
- }
- /* FIXME: Encode extra hash bits! */
- return tdb_write_off(tdb, hoff + num * sizeof(tdb_off_t), off);
+ /* Gcc warns if you miss a case in the switch, so use that. */
+ switch (ecode) {
+ case TDB_SUCCESS: return "Success";
+ case TDB_ERR_CORRUPT: return "Corrupt database";
+ case TDB_ERR_IO: return "IO Error";
+ case TDB_ERR_LOCK: return "Locking error";
+ case TDB_ERR_OOM: return "Out of memory";
+ case TDB_ERR_EXISTS: return "Record exists";
+ case TDB_ERR_EINVAL: return "Invalid parameter";
+ case TDB_ERR_NOEXIST: return "Record does not exist";
+ case TDB_ERR_RDONLY: return "write not permitted";
+ }
+ return "Invalid error code";
}
-static int unlink_used_record(struct tdb_context *tdb, tdb_off_t chain,
- uint64_t *extra_locks)
+enum TDB_ERROR tdb_error(struct tdb_context *tdb)
{
- tdb_off_t num, len, i, hoff;
-
- /* FIXME: Maybe lock more in search? Maybe don't lock if scan
- * finds none? */
-again:
- len = (1ULL << tdb->header.v.hash_bits) - (chain + 1);
- hoff = tdb->header.v.hash_off + (chain + 1) * sizeof(tdb_off_t);
- num = tdb_find_zero_off(tdb, hoff, len);
-
- /* We want to lock the zero entry, too. In the wrap case,
- * this locks one extra. That's harmless. */
- num++;
-
- for (i = chain + 1; i < chain + 1 + num; i++) {
- if (tdb_lock_list(tdb, i, F_WRLCK, TDB_LOCK_WAIT) == -1) {
- if (i != chain + 1)
- unlock_lists(tdb, chain + 1, i-1, F_WRLCK);
- return -1;
- }
- }
-
- /* The wrap case: we need those locks out of order! */
- if (unlikely(num == len + 1)) {
- *extra_locks = tdb_find_zero_off(tdb, tdb->header.v.hash_off,
- 1ULL << tdb->header.v.hash_bits);
- (*extra_locks)++;
- for (i = 0; i < *extra_locks; i++) {
- if (tdb_lock_list(tdb, i, F_WRLCK, TDB_LOCK_NOWAIT)) {
- /* Failed. Caller must lock in order. */
- if (i)
- unlock_lists(tdb, 0, i-1, F_WRLCK);
- unlock_lists(tdb, chain + 1, chain + num,
- F_WRLCK);
- return 1;
- }
- }
- num += *extra_locks;
- }
-
- /* Now we have the locks, be certain that offset is still 0! */
- hoff = tdb->header.v.hash_off
- + (((chain + num) * sizeof(tdb_off_t))
- & ((1ULL << tdb->header.v.hash_bits) - 1));
-
- if (unlikely(tdb_read_off(tdb, hoff) != 0)) {
- unlock_lists(tdb, chain + 1, chain + num, F_WRLCK);
- goto again;
- }
+ return tdb->last_error;
+}
- /* OK, all locked. Unlink first one. */
- hoff = tdb->header.v.hash_off + chain * sizeof(tdb_off_t);
- if (tdb_write_off(tdb, hoff, 0) == -1)
- goto unlock_err;
-
- /* Rehash the rest. */
- for (i = 1; i < num; i++) {
- tdb_off_t off;
- uint64_t h;
-
- hoff = tdb->header.v.hash_off
- + (((chain + i) * sizeof(tdb_off_t))
- & ((1ULL << tdb->header.v.hash_bits) - 1));
- off = tdb_read_off(tdb, hoff);
- if (unlikely(off == TDB_OFF_ERR))
- goto unlock_err;
-
- /* Maybe use a bit to indicate it is in ideal place? */
- h = hash_record(tdb, off);
- /* Is it happy where it is? */
- if ((h & ((1ULL << tdb->header.v.hash_bits)-1)) == (chain + i))
- continue;
-
- /* Remove it. */
- if (tdb_write_off(tdb, hoff, 0) == -1)
- goto unlock_err;
-
- /* Rehash it. */
- if (hash_add(tdb, h, off) == -1)
- goto unlock_err;
+enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
+ enum TDB_ERROR ecode,
+ enum tdb_log_level level,
+ const char *fmt, ...)
+{
+ char *message;
+ va_list ap;
+ size_t len;
+ /* tdb_open paths care about errno, so save it. */
+ int saved_errno = errno;
+
+ if (!tdb->log_fn)
+ return ecode;
+
+ va_start(ap, fmt);
+ len = vasprintf(&message, fmt, ap);
+ va_end(ap);
+
+ if (len < 0) {
+ tdb->log_fn(tdb, TDB_LOG_ERROR,
+ "out of memory formatting message:", tdb->log_data);
+ tdb->log_fn(tdb, level, fmt, tdb->log_data);
+ } else {
+ tdb->log_fn(tdb, level, message, tdb->log_data);
+ free(message);
}
- unlock_lists(tdb, chain + 1, chain + num, F_WRLCK);
- return 0;
-
-unlock_err:
- unlock_lists(tdb, chain + 1, chain + num, F_WRLCK);
- return -1;
+ errno = saved_errno;
+ return ecode;
}
-int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
+enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
+ TDB_DATA key,
+ enum TDB_ERROR (*parse)(TDB_DATA k,
+ TDB_DATA d,
+ void *data),
+ void *data)
{
- tdb_off_t off, start, end, room, extra_locks = 0;
- uint64_t h;
- int ret;
-
- h = tdb_hash(tdb, key.dptr, key.dsize);
- off = find_bucket_and_lock(tdb, &key, h, &start, &end, &room, F_WRLCK);
- if (off == TDB_OFF_ERR)
- return -1;
-
- if (off == 0) {
- unlock_lists(tdb, start, end, F_WRLCK);
- tdb->ecode = TDB_ERR_NOEXIST;
- return -1;
- }
+ tdb_off_t off;
+ struct tdb_used_record rec;
+ struct hash_info h;
+ enum TDB_ERROR ecode;
- ret = unlink_used_record(tdb, end, &extra_locks);
- if (unlikely(ret == 1)) {
- unsigned int i;
+ off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
+ if (TDB_OFF_IS_ERR(off)) {
+ return tdb->last_error = off;
+ }
- unlock_lists(tdb, start, end, F_WRLCK);
+ if (!off) {
+ ecode = TDB_ERR_NOEXIST;
+ } else {
+ const void *dptr;
+ dptr = tdb_access_read(tdb, off + sizeof(rec) + key.dsize,
+ rec_data_length(&rec), false);
+ if (TDB_PTR_IS_ERR(dptr)) {
+ ecode = TDB_PTR_ERR(dptr);
+ } else {
+ TDB_DATA d = tdb_mkdata(dptr, rec_data_length(&rec));
- /* We need extra locks at the start. */
- for (i = 0; i < extra_locks; i++) {
- if (tdb_lock_list(tdb, i, F_WRLCK, TDB_LOCK_WAIT)) {
- if (i)
- unlock_lists(tdb, 0, i-1, F_WRLCK);
- return -1;
- }
+ ecode = parse(key, d, data);
+ tdb_access_release(tdb, dptr);
}
- /* Try again now we're holding more locks. */
- ret = tdb_delete(tdb, key);
- unlock_lists(tdb, 0, i, F_WRLCK);
- return ret;
}
- unlock_lists(tdb, start, end, F_WRLCK);
- return ret;
+
+ tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
+ return tdb->last_error = ecode;
}
-int tdb_close(struct tdb_context *tdb)
+const char *tdb_name(const struct tdb_context *tdb)
{
- struct tdb_context **i;
- int ret = 0;
-
- /* FIXME:
- if (tdb->transaction) {
- tdb_transaction_cancel(tdb);
- }
- */
- tdb_trace(tdb, "tdb_close");
-
- if (tdb->map_ptr) {
- if (tdb->flags & TDB_INTERNAL)
- free(tdb->map_ptr);
- else
- tdb_munmap(tdb);
- }
- free((char *)tdb->name);
- if (tdb->fd != -1) {
- ret = close(tdb->fd);
- tdb->fd = -1;
- }
- free(tdb->lockrecs);
-
- /* Remove from contexts list */
- for (i = &tdbs; *i; i = &(*i)->next) {
- if (*i == tdb) {
- *i = tdb->next;
- break;
- }
- }
+ return tdb->name;
+}
-#ifdef TDB_TRACE
- close(tdb->tracefd);
-#endif
- free(tdb);
+int64_t tdb_get_seqnum(struct tdb_context *tdb)
+{
+ tdb_off_t off = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
+ if (TDB_OFF_IS_ERR(off))
+ tdb->last_error = off;
+ else
+ tdb->last_error = TDB_SUCCESS;
+ return off;
+}
+
- return ret;
+int tdb_fd(const struct tdb_context *tdb)
+{
+ return tdb->file->fd;
}