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)

diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c
index 34681ea78f28fea90617ad1699fae9e37abd7eef..f5809ef63ad3d3ad9de4037ee69aca4a3d41bb2d 100644 (file)
--- 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;