There are a few operations in rev-list that are optimized for bitmaps.
Rather than having the code inline in cmd_rev_list(), let's move them
into helpers. This not only makes the flow of the main function simpler,
but it lets us replace the complex "can we do the optimization?"
conditionals with a series of early returns from the functions. That
also makes it easy to add comments explaining those conditions.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
builtin/rev-list.c | 88 +++++++++++++++++++++++++++++++++++-----------
1 file changed, 67 insertions(+), 21 deletions(-)
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 4cb5a52dee..38c5ca5603 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -364,6 +364,69 @@ static inline int parse_missing_action_value(const char *value)
return 0;
}
+static int try_bitmap_count(struct rev_info *revs)
+{
+ uint32_t commit_count;
+ int max_count;
+ struct bitmap_index *bitmap_git;
+
+ /* This function only handles counting, not general traversal. */
+ if (!revs->count)
+ return -1;
+
+ /*
+ * A bitmap result can't know left/right, etc, because we don't
+ * actually traverse.
+ */
+ if (revs->left_right || revs->cherry_mark)
+ return -1;
+
+ /*
+ * This must be saved before doing any walking, since the revision
+ * machinery will count it down to zero while traversing.
+ */
+ max_count = revs->max_count;
+
+ bitmap_git = prepare_bitmap_walk(revs);
+ if (!bitmap_git)
+ return -1;
+
+ count_bitmap_commit_list(bitmap_git, &commit_count, NULL, NULL, NULL);
+ if (max_count >= 0 && max_count < commit_count)
+ commit_count = max_count;
+
+ printf("%d\n", commit_count);
+ free_bitmap_index(bitmap_git);
+ return 0;
+}
+
+static int try_bitmap_traversal(struct rev_info *revs)
+{
+ struct bitmap_index *bitmap_git;
+
+ /*
+ * We can't use a bitmap result with a traversal limit, since the set
+ * of commits we'd get would be essentially random.
+ */
+ if (revs->max_count >= 0)
+ return -1;
+
+ /*
+ * Our bitmap result will return all objects, and we're not
+ * yet prepared to show only particular types.
+ */
+ if (!revs->tag_objects || !revs->tree_objects || !revs->blob_objects)
+ return -1;
+
+ bitmap_git = prepare_bitmap_walk(revs);
+ if (!bitmap_git)
+ return -1;
+
+ traverse_bitmap_commit_list(bitmap_git, &show_object_fast);
+ free_bitmap_index(bitmap_git);
+ return 0;
+}
+
int cmd_rev_list(int argc, const char **argv, const char *prefix)
{
struct rev_info revs;
@@ -534,27 +597,10 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
progress = start_delayed_progress(show_progress, 0);
if (use_bitmap_index) {
- if (revs.count && !revs.left_right && !revs.cherry_mark) {
- uint32_t commit_count;
- int max_count = revs.max_count;
- struct bitmap_index *bitmap_git;
- if ((bitmap_git = prepare_bitmap_walk(&revs))) {
- count_bitmap_commit_list(bitmap_git, &commit_count, NULL, NULL, NULL);
- if (max_count >= 0 && max_count < commit_count)
- commit_count = max_count;
- printf("%d\n", commit_count);
- free_bitmap_index(bitmap_git);
- return 0;
- }
- } else if (revs.max_count < 0 &&
- revs.tag_objects && revs.tree_objects && revs.blob_objects) {
- struct bitmap_index *bitmap_git;
- if ((bitmap_git = prepare_bitmap_walk(&revs))) {
- traverse_bitmap_commit_list(bitmap_git, &show_object_fast);
- free_bitmap_index(bitmap_git);
- return 0;
- }
- }
+ if (!try_bitmap_count(&revs))
+ return 0;
+ if (!try_bitmap_traversal(&revs))
+ return 0;
}
if (prepare_revision_walk(&revs))
--
2.25.0.796.gcc29325708
