Author: vlendec Date: 2007-02-19 11:19:53 +0000 (Mon, 19 Feb 2007) New Revision: 21444
WebSVN: http://websvn.samba.org/cgi-bin/viewcvs.cgi?view=rev&root=samba&rev=21444 Log: Check in tdb_parse_record. Not merging to the other branches yet, we need to agree on the behaviour of non-existing records. Tridge, can you comment? Should we change tdb_fetch, or should we have different concepts in tdb_fetch() and tdb_parse_record() ? Volker Modified: branches/SAMBA_3_0/source/tdb/common/io.c branches/SAMBA_3_0/source/tdb/common/tdb.c branches/SAMBA_3_0/source/tdb/common/tdb_private.h branches/SAMBA_3_0/source/tdb/include/tdb.h Changeset: Modified: branches/SAMBA_3_0/source/tdb/common/io.c =================================================================== --- branches/SAMBA_3_0/source/tdb/common/io.c 2007-02-19 01:51:46 UTC (rev 21443) +++ branches/SAMBA_3_0/source/tdb/common/io.c 2007-02-19 11:19:53 UTC (rev 21444) @@ -355,6 +355,40 @@ return buf; } +/* Give a piece of tdb data to a parser */ + +int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key, + tdb_off_t offset, tdb_len_t len, + int (*parser)(TDB_DATA key, TDB_DATA data, + void *private_data), + void *private_data) +{ + TDB_DATA data; + int result; + + data.dsize = len; + + if ((tdb->transaction == NULL) && (tdb->map_ptr != NULL)) { + /* + * Optimize by avoiding the malloc/memcpy/free, point the + * parser directly at the mmap area. + */ + if (tdb->methods->tdb_oob(tdb, offset+len, 0) != 0) { + return -1; + } + data.dptr = offset + (char *)tdb->map_ptr; + return parser(key, data, private_data); + } + + if (!(data.dptr = tdb_alloc_read(tdb, offset, len))) { + return -1; + } + + result = parser(key, data, private_data); + free(data.dptr); + return result; +} + /* read/write a record */ int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec) { Modified: branches/SAMBA_3_0/source/tdb/common/tdb.c =================================================================== --- branches/SAMBA_3_0/source/tdb/common/tdb.c 2007-02-19 01:51:46 UTC (rev 21443) +++ branches/SAMBA_3_0/source/tdb/common/tdb.c 2007-02-19 11:19:53 UTC (rev 21444) @@ -56,6 +56,10 @@ tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1, 1); } +static int tdb_key_compare(TDB_DATA key, TDB_DATA data, void *private_data) +{ + return memcmp(data.dptr, key.dptr, data.dsize); +} /* Returns 0 on fail. On success, return offset of record, and fills in rec */ @@ -73,19 +77,12 @@ if (tdb_rec_read(tdb, rec_ptr, r) == -1) return 0; - if (!TDB_DEAD(r) && hash==r->full_hash && key.dsize==r->key_len) { - char *k; - /* a very likely hit - read the key */ - k = tdb_alloc_read(tdb, rec_ptr + sizeof(*r), - r->key_len); - if (!k) - return 0; - - if (memcmp(key.dptr, k, key.dsize) == 0) { - SAFE_FREE(k); - return rec_ptr; - } - SAFE_FREE(k); + if (!TDB_DEAD(r) && hash==r->full_hash + && key.dsize==r->key_len + && tdb_parse_data(tdb, key, rec_ptr + sizeof(*r), + r->key_len, tdb_key_compare, + NULL) == 0) { + return rec_ptr; } rec_ptr = r->next; } @@ -163,6 +160,54 @@ return ret; } +/* + * Find an entry in the database and hand the record's data to a parsing + * function. The parsing function is executed under the chain read lock, so it + * should be fast and should not block on other syscalls. + * + * DONT CALL OTHER TDB CALLS FROM THE PARSER, THIS MIGHT LEAD TO SEGFAULTS. + * + * For mmapped tdb's that do not have a transaction open it points the parsing + * function directly at the mmap area, it avoids the malloc/memcpy in this + * case. If a transaction is open or no mmap is available, it has to do + * malloc/read/parse/free. + * + * This is interesting for all readers of potentially large data structures in + * the tdb records, ldb indexes being one example. + */ + +int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key, + int (*parser)(TDB_DATA key, TDB_DATA data, + void *private_data), + void *private_data) +{ + tdb_off_t rec_ptr; + struct list_struct rec; + TDB_DATA data; + int ret; + u32 hash; + + /* find which hash bucket it is in */ + hash = tdb->hash_fn(&key); + + rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec); + + if (rec_ptr == 0) { + data.dptr = NULL; + data.dsize = 0; + return parser(key, data, private_data); + } + + ret = tdb_parse_data(tdb, key, rec_ptr + sizeof(rec) + rec.key_len, + rec.data_len, parser, private_data); + + tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); + + return ret; + +} + + /* check if an entry in the database exists note that 1 is returned if the key is found and 0 is returned if not found Modified: branches/SAMBA_3_0/source/tdb/common/tdb_private.h =================================================================== --- branches/SAMBA_3_0/source/tdb/common/tdb_private.h 2007-02-19 01:51:46 UTC (rev 21443) +++ branches/SAMBA_3_0/source/tdb/common/tdb_private.h 2007-02-19 11:19:53 UTC (rev 21444) @@ -196,6 +196,11 @@ int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec); char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len); +int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key, + tdb_off_t offset, tdb_len_t len, + int (*parser)(TDB_DATA key, TDB_DATA data, + void *private_data), + void *private_data); tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, int locktype, struct list_struct *rec); void tdb_io_init(struct tdb_context *tdb); Modified: branches/SAMBA_3_0/source/tdb/include/tdb.h =================================================================== --- branches/SAMBA_3_0/source/tdb/include/tdb.h 2007-02-19 01:51:46 UTC (rev 21443) +++ branches/SAMBA_3_0/source/tdb/include/tdb.h 2007-02-19 11:19:53 UTC (rev 21444) @@ -101,6 +101,10 @@ enum TDB_ERROR tdb_error(struct tdb_context *tdb); const char *tdb_errorstr(struct tdb_context *tdb); TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key); +int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key, + int (*parser)(TDB_DATA key, TDB_DATA data, + void *private_data), + void *private_data); int tdb_delete(struct tdb_context *tdb, TDB_DATA key); int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag); int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf);
