When trying to get a list of remote tags to see if we need to fetch
any we were doing a linear search for the matching tag ref for the
tag^{} commit entries. This proves to be incredibly slow for large
numbers of tags. Rewrite the function so that we can do lookup in
string_lists instead.
For a repository with 50000 tags (and just a single commit on a single
branch), a fetch that does nothing goes from ~ 1m50s to ~4.2s.
Signed-off-by: Julian Phillips <julian@xxxxxxxxxxxxxxxxx>
---
Not only does this not require a custom hash table, it is also slightly
faster than the last version (~4.2s vs ~4.5s).
If nothing else, having rewritten it completely, at least I now
understand what the old find_non_local_tags function was actually doing
... ;)
builtin-fetch.c | 85 ++++++++++++++++++++++++++++++++++++++-----------------
1 files changed, 59 insertions(+), 26 deletions(-)
diff --git a/builtin-fetch.c b/builtin-fetch.c
index cb48c57..c9a2563 100644
--- a/builtin-fetch.c
+++ b/builtin-fetch.c
@@ -504,57 +504,90 @@ static int will_fetch(struct ref **head, const unsigned char *sha1)
return 0;
}
+struct tag_data {
+ struct ref **head;
+ struct ref ***tail;
+ struct string_list *refs;
+};
+
+static int add_to_tail(struct string_list_item *item, void *cb_data)
+{
+ struct tag_data *data = (struct tag_data *)cb_data;
+ unsigned char *commit = (unsigned char *)item->util;
+ struct ref *rm = NULL;
+ struct string_list_item *sli;
+
+ /* Tag objects will have the commit sha1 associated with the peeled
+ * ref, if there is not a peeled ref then the ref is probably a
+ * lightweight tag and so refers to a commit directly */
+ sli = string_list_lookup(item->string, data->refs);
+ if (sli)
+ commit = sli->util;
+
+ /* skip over tags that we don't have the commits for. */
+ if (!has_sha1_file(commit) && !will_fetch(data->head, commit))
+ return 0;
+
+ rm = alloc_ref(item->string);
+ rm->peer_ref = alloc_ref(item->string);
+ hashcpy(rm->old_sha1, item->util);
+
+ **data->tail = rm;
+ *data->tail = &rm->next;
+
+ return 0;
+}
+
static void find_non_local_tags(struct transport *transport,
struct ref **head,
struct ref ***tail)
{
struct string_list existing_refs = { NULL, 0, 0, 0 };
- struct string_list new_refs = { NULL, 0, 0, 1 };
+ struct string_list peeled_refs = { NULL, 0, 0, 1 };
+ struct string_list remote_refs = { NULL, 0, 0, 1 };
+ struct tag_data data = {head, tail, &peeled_refs};
+ struct string_list *refs;
char *ref_name;
int ref_name_len;
- const unsigned char *ref_sha1;
- const struct ref *tag_ref;
- struct ref *rm = NULL;
const struct ref *ref;
+ struct string_list_item *item;
for_each_ref(add_existing, &existing_refs);
for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
if (prefixcmp(ref->name, "refs/tags"))
continue;
+ /* skip duplicates */
+ if (string_list_lookup(ref->name, &remote_refs))
+ continue;
+
+ refs = &remote_refs;
ref_name = xstrdup(ref->name);
ref_name_len = strlen(ref_name);
- ref_sha1 = ref->old_sha1;
+ /* we want to store peeled refs by the base ref name in the
+ * peeled_refs string list */
if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
ref_name[ref_name_len - 3] = 0;
- tag_ref = transport_get_remote_refs(transport);
- while (tag_ref) {
- if (!strcmp(tag_ref->name, ref_name)) {
- ref_sha1 = tag_ref->old_sha1;
- break;
- }
- tag_ref = tag_ref->next;
- }
+ refs = &peeled_refs;
}
- if (!string_list_has_string(&existing_refs, ref_name) &&
- !string_list_has_string(&new_refs, ref_name) &&
- (has_sha1_file(ref->old_sha1) ||
- will_fetch(head, ref->old_sha1))) {
- string_list_insert(ref_name, &new_refs);
-
- rm = alloc_ref(ref_name);
- rm->peer_ref = alloc_ref(ref_name);
- hashcpy(rm->old_sha1, ref_sha1);
-
- **tail = rm;
- *tail = &rm->next;
+ /* ignore refs that we already have */
+ if (!string_list_has_string(&existing_refs, ref_name)) {
+ item = string_list_insert(ref_name, refs);
+ item->util = (void *)ref->old_sha1;
}
+
free(ref_name);
}
+
+ /* For all the tags in the remote_refs string list, call add_to_tail to
+ * add them to the list of refs to be fetched */
+ for_each_string_list(add_to_tail, &remote_refs, &data);
+
string_list_clear(&existing_refs, 0);
- string_list_clear(&new_refs, 0);
+ string_list_clear(&peeled_refs, 0);
+ string_list_clear(&remote_refs, 0);
}
static void check_not_current_branch(struct ref *ref_map)
--
1.6.4.2
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