From: Julian Phillips Date: Wed, 16 Sep 2009 07:53:03 GMT Subject: [RFC/PATCH 2/2] fetch: Speed up fetch by using ref dictionary Message-ID: <20090916075304.58044.83034.julian@quantumfyre.co.uk> In-Reply-To: <20090916074737.58044.42776.julian@quantumfyre.co.uk> 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. For a repository with 50000 tags (and just a single commit on a single branch), a fetch that does nothing goes from ~ 1m50s to ~4.5s. Signed-off-by: Julian Phillips --- builtin-fetch.c | 19 +++++++++---------- 1 files changed, 9 insertions(+), 10 deletions(-) diff --git a/builtin-fetch.c b/builtin-fetch.c index cb48c57..16cfee6 100644 --- a/builtin-fetch.c +++ b/builtin-fetch.c @@ -11,6 +11,7 @@ #include "run-command.h" #include "parse-options.h" #include "sigchain.h" +#include "ref-dict.h" static const char * const builtin_fetch_usage[] = { "git fetch [options] [ ...]", @@ -513,12 +514,16 @@ static void find_non_local_tags(struct transport *transport, char *ref_name; int ref_name_len; const unsigned char *ref_sha1; - const struct ref *tag_ref; + unsigned char tag_sha1[40]; struct ref *rm = NULL; const struct ref *ref; + struct hash_table dict; + const struct ref *remote_refs = transport_get_remote_refs(transport); + + ref_dict_create(&dict, remote_refs); for_each_ref(add_existing, &existing_refs); - for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) { + for (ref = remote_refs; ref; ref = ref->next) { if (prefixcmp(ref->name, "refs/tags")) continue; @@ -528,14 +533,8 @@ static void find_non_local_tags(struct transport *transport, 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; - } + if (ref_dict_get(&dict, ref_name, tag_sha1)) + ref_sha1 = tag_sha1; } if (!string_list_has_string(&existing_refs, ref_name) && -- 1.6.4.2