Merge branch 'ps/reftable-iteration-perf'

[thirdparty/git.git] / reftable / merged.c

diff --git a/reftable/merged.c b/reftable/merged.c
index a0f222e07bdf7519ed1c0d8d43ccbb6151663c3a..1aa6cd31b74954da9b1b5140cd350459c37c1378 100644 (file)
--- a/reftable/merged.c
+++ b/reftable/merged.c
@@ -49,8 +49,6 @@ static void merged_iter_close(void *p)
        for (size_t i = 0; i < mi->stack_len; i++)
                reftable_iterator_destroy(&mi->stack[i]);
        reftable_free(mi->stack);
-       strbuf_release(&mi->key);
-       strbuf_release(&mi->entry_key);
 }
 
 static int merged_iter_advance_nonnull_subiter(struct merged_iter *mi,
@@ -105,14 +103,19 @@ static int merged_iter_next_entry(struct merged_iter *mi,
          such a deployment, the loop below must be changed to collect all
          entries for the same key, and return new the newest one.
        */
-       reftable_record_key(&entry.rec, &mi->entry_key);
        while (!merged_iter_pqueue_is_empty(mi->pq)) {
                struct pq_entry top = merged_iter_pqueue_top(mi->pq);
-               int cmp = 0;
-
-               reftable_record_key(&top.rec, &mi->key);
+               int cmp;
+
+               /*
+                * When the next entry comes from the same queue as the current
+                * entry then it must by definition be larger. This avoids a
+                * comparison in the most common case.
+                */
+               if (top.index == entry.index)
+                       break;
 
-               cmp = strbuf_cmp(&mi->key, &mi->entry_key);
+               cmp = reftable_record_cmp(&top.rec, &entry.rec);
                if (cmp > 0)
                        break;
 
@@ -243,8 +246,6 @@ static int merged_table_seek_record(struct reftable_merged_table *mt,
                .typ = reftable_record_type(rec),
                .hash_id = mt->hash_id,
                .suppress_deletions = mt->suppress_deletions,
-               .key = STRBUF_INIT,
-               .entry_key = STRBUF_INIT,
        };
        struct merged_iter *p;
        int err;