From 6007eae33919ac508b01bbe448d18814e22d4c44 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Sat, 6 Sep 2003 19:59:12 +0000 Subject: Change some internal interfaces to cause the hash (which is *expensive*) to be calculated less often. No change to external interface. Jeremy. (This used to be commit 155c9ce6663df9963c7563adf78a232d3650b7b5) --- source3/tdb/tdb.c | 49 +++++++++++++++++++++++++++++++------------------ 1 file changed, 31 insertions(+), 18 deletions(-) diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c index 34681ea78f..f5809ef63a 100644 --- a/source3/tdb/tdb.c +++ b/source3/tdb/tdb.c @@ -1015,12 +1015,11 @@ static int tdb_keylocked(TDB_CONTEXT *tdb, u32 hash) } /* As tdb_find, but if you succeed, keep the lock */ -static tdb_off tdb_find_lock(TDB_CONTEXT *tdb, TDB_DATA key, int locktype, +static tdb_off tdb_find_lock_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, int locktype, struct list_struct *rec) { - u32 hash, rec_ptr; + u32 rec_ptr; - hash = tdb_hash(&key); if (!tdb_keylocked(tdb, hash)) return 0; if (tdb_lock(tdb, BUCKET(hash), locktype) == -1) @@ -1061,13 +1060,13 @@ const char *tdb_errorstr(TDB_CONTEXT *tdb) on failure return -1. */ -static int tdb_update(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf) +static int tdb_update_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf) { struct list_struct rec; tdb_off rec_ptr; /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec))) + if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) return -1; /* must be long enough key, data and tailer */ @@ -1101,9 +1100,11 @@ TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) tdb_off rec_ptr; struct list_struct rec; TDB_DATA ret; + u32 hash; /* find which hash bucket it is in */ - if (!(rec_ptr = tdb_find_lock(tdb,key,F_RDLCK,&rec))) + hash = tdb_hash(&key); + if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) return tdb_null; if (rec.data_len) @@ -1122,16 +1123,22 @@ TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key) this doesn't match the conventions in the rest of this module, but is compatible with gdbm */ -int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) +static int tdb_exists_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash) { struct list_struct rec; - if (tdb_find_lock(tdb, key, F_RDLCK, &rec) == 0) + if (tdb_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0) return 0; tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); return 1; } +int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) +{ + u32 hash = tdb_hash(&key); + return tdb_exists_hash(tdb, key, hash); +} + /* record lock stops delete underneath */ static int lock_record(TDB_CONTEXT *tdb, tdb_off off) { @@ -1388,7 +1395,7 @@ TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey) if (!tdb->travlocks.off) { /* No previous element: do normal find, and lock record */ - tdb->travlocks.off = tdb_find_lock(tdb, oldkey, F_WRLCK, &rec); + tdb->travlocks.off = tdb_find_lock_hash(tdb, oldkey, tdb_hash(&oldkey), F_WRLCK, &rec); if (!tdb->travlocks.off) return tdb_null; tdb->travlocks.hash = BUCKET(rec.full_hash); @@ -1416,13 +1423,13 @@ TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA oldkey) } /* delete an entry in the database given a key */ -int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) +static int tdb_delete_hash(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash) { tdb_off rec_ptr; struct list_struct rec; int ret; - if (!(rec_ptr = tdb_find_lock(tdb, key, F_WRLCK, &rec))) + if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK, &rec))) return -1; ret = do_delete(tdb, rec_ptr, &rec); if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0) @@ -1430,6 +1437,12 @@ int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) return ret; } +int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key) +{ + u32 hash = tdb_hash(&key); + return tdb_delete_hash(tdb, key, hash); +} + /* store an element in the database, replacing any existing element with the same key @@ -1452,13 +1465,13 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) /* check for it existing, on insert. */ if (flag == TDB_INSERT) { - if (tdb_exists(tdb, key)) { + if (tdb_exists_hash(tdb, key, hash)) { tdb->ecode = TDB_ERR_EXISTS; goto fail; } } else { /* first try in-place update, on modify or replace. */ - if (tdb_update(tdb, key, dbuf) == 0) + if (tdb_update_hash(tdb, key, hash, dbuf) == 0) goto out; if (flag == TDB_MODIFY && tdb->ecode == TDB_ERR_NOEXIST) goto fail; @@ -1470,7 +1483,7 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) care. Doing this first reduces fragmentation, and avoids coalescing with `allocated' block before it's updated. */ if (flag != TDB_INSERT) - tdb_delete(tdb, key); + tdb_delete_hash(tdb, key, hash); /* Copy key+value *before* allocating free space in case malloc fails and we are left with a dead spot in the tdb. */ @@ -1519,13 +1532,13 @@ fail: is <= the old data size and the key exists. on failure return -1. Record must be locked before calling. */ -static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) +static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, u32 hash, TDB_DATA new_dbuf) { struct list_struct rec; tdb_off rec_ptr; /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, tdb_hash(&key), &rec))) + if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) return -1; /* Append of 0 is always ok. */ @@ -1567,7 +1580,7 @@ int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) return -1; /* first try in-place. */ - if (tdb_append_inplace(tdb, key, new_dbuf) == 0) + if (tdb_append_inplace(tdb, key, hash, new_dbuf) == 0) goto out; /* reset the error code potentially set by the tdb_append_inplace() */ @@ -1610,7 +1623,7 @@ int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) care. Doing this first reduces fragmentation, and avoids coalescing with `allocated' block before it's updated. */ - tdb_delete(tdb, key); + tdb_delete_hash(tdb, key, hash); if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec))) goto fail; -- cgit