rev-list: factor out bitmap-optimized routines

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@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2020-02-14 13:22:18 -05:00 коммит произвёл Junio C Hamano
Родитель d90fe06ea7
Коммит 792f811998
1 изменённых файлов: 67 добавлений и 21 удалений

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@ -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))