Optimize index creation on large object sets in fast-import.

diff --git a/fast-import.c b/fast-import.c
index 207acb3230f1c3a8b7843e82da282729ad4be37a..cfadda043296474ebb5f11a917eb8aa745ba786a 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -678,10 +678,15 @@ static void write_index(const char *idx_name)
        idx = xmalloc(object_count * sizeof(struct object_entry*));
        c = idx;
        for (o = blocks; o; o = o->next_pool)
-               for (e = o->entries; e != o->next_free; e++)
-                       if (pack_id == e->pack_id)
-                               *c++ = e;
+               for (e = o->next_free; e-- != o->entries;) {
+                       if (pack_id != e->pack_id)
+                               goto sort_index;
+                       *c++ = e;
+               }
+sort_index:
        last = idx + object_count;
+       if (c != last)
+               die("internal consistency error creating the index");
        qsort(idx, object_count, sizeof(struct object_entry*), oecmp);
 
        /* Generate the fan-out array. */