[PATCH] fetch-pack: binary search when storing wanted-refs
- From
- Jonathan Tan <jonathantanmy@google.com>
- Date
- Mar 27, 2019, 21:11 UTC
- Message-ID
- <20190327211110.46327-1-jonathantanmy@google.com>
In do_fetch_pack_v2(), the "sought" array is sorted by name, and it is not subsequently reordered (within the function). Therefore, receive_wanted_refs() can assume that "sought" is sorted, and can thus use a binary search when storing wanted-refs retrieved from the server.
Replace the existing linear search with a binary search. This improves performance significantly when mirror cloning a repository with more than 1 million refs.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> --- fetch-pack.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/fetch-pack.c b/fetch-pack.c index e69993b2eb..e8266bd45a 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -1298,6 +1298,11 @@ static void receive_shallow_info(struct fetch_pack_args *args, } } +static int cmp_name_ref(const void *name, const void *ref) +{ + return strcmp(name, (*(struct ref **)ref)->name); +} + static void receive_wanted_refs(struct packet_reader *reader, struct ref **sought, int nr_sought) { @@ -1305,20 +1310,16 @@ static void receive_wanted_refs(struct packet_reader *reader, while (packet_reader_read(reader) == PACKET_READ_NORMAL) { struct object_id oid; const char *end; - int i; + struct ref **found; if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ') die(_("expected wanted-ref, got '%s'"), reader->line); - for (i = 0; i < nr_sought; i++) { - if (!strcmp(end, sought[i]->name)) { - oidcpy(&sought[i]->old_oid, &oid); - break; - } - } - - if (i == nr_sought) + found = bsearch(end, sought, nr_sought, sizeof(*sought), + cmp_name_ref); + if (!found) die(_("unexpected wanted-ref: '%s'"), reader->line); + oidcpy(&(*found)->old_oid, &oid); } if (reader->status != PACKET_READ_DELIM)
-- 2.21.0.197.gd478713db0