tdb: Don't malloc for every record in traverse

This gains a few percent in tdbbackup

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Michael Adam <obnox@samba.org>
Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri Jul 15 00:52:00 CEST 2016 on sn-devel-144

diff --git a/lib/tdb/common/traverse.c b/lib/tdb/common/traverse.c
index e18e3c34fd30263562009e7d115111d11096bbba..f33ef34ab8d344ad633396580457a63ebc543420 100644 (file)
--- a/lib/tdb/common/traverse.c
+++ b/lib/tdb/common/traverse.c
@@ -148,6 +148,13 @@ static int tdb_traverse_internal(struct tdb_context *tdb,
        struct tdb_record rec;
        int ret = 0, count = 0;
        tdb_off_t off;
+       size_t recbuf_len;
+
+       recbuf_len = 4096;
+       key.dptr = malloc(recbuf_len);
+       if (key.dptr == NULL) {
+               return -1;
+       }
 
        /* This was in the initialization, above, but the IRIX compiler
         * did not like it.  crh
@@ -159,15 +166,44 @@ static int tdb_traverse_internal(struct tdb_context *tdb,
 
        /* tdb_next_lock places locks on the record returned, and its chain */
        while ((off = tdb_next_lock(tdb, tl, &rec)) != 0) {
+               tdb_len_t full_len = rec.key_len + rec.data_len;
+               int nread;
+
+               if (full_len > recbuf_len) {
+                       recbuf_len = full_len;
+
+                       /*
+                        * No realloc, we don't need the old data and thus can
+                        * do without the memcpy
+                        */
+                       free(key.dptr);
+                       key.dptr = malloc(recbuf_len);
+
+                       if (key.dptr == NULL) {
+                               ret = -1;
+                               if (tdb_unlock(tdb, tl->hash, tl->lock_rw)
+                                   != 0) {
+                                       goto out;
+                               }
+                               if (tdb_unlock_record(tdb, tl->off) != 0) {
+                                       TDB_LOG((tdb, TDB_DEBUG_FATAL,
+                                                "tdb_traverse: malloc "
+                                                "failed and unlock_record "
+                                                "failed!\n"));
+                               }
+                               goto out;
+                       }
+               }
+
                if (off == TDB_NEXT_LOCK_ERR) {
                        ret = -1;
                        goto out;
                }
                count++;
                /* now read the full record */
-               key.dptr = tdb_alloc_read(tdb, tl->off + sizeof(rec),
-                                         rec.key_len + rec.data_len);
-               if (!key.dptr) {
+               nread = tdb->methods->tdb_read(tdb, tl->off + sizeof(rec),
+                                              key.dptr, full_len, 0);
+               if (nread == -1) {
                        ret = -1;
                        if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0)
                                goto out;
@@ -184,7 +220,6 @@ static int tdb_traverse_internal(struct tdb_context *tdb,
                /* Drop chain lock, call out */
                if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) {
                        ret = -1;
-                       SAFE_FREE(key.dptr);
                        goto out;
                }
                if (fn && fn(tdb, key, dbuf, private_data)) {
@@ -194,13 +229,12 @@ static int tdb_traverse_internal(struct tdb_context *tdb,
                                TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: unlock_record failed!\n"));;
                                ret = -1;
                        }
-                       SAFE_FREE(key.dptr);
                        goto out;
                }
-               SAFE_FREE(key.dptr);
        }
        tdb_trace(tdb, "tdb_traverse_end");
 out:
+       SAFE_FREE(key.dptr);
        tdb->travlocks.next = tl->next;
        if (ret < 0)
                return -1;