upload-pack: Implement no-done capability

If the client requests both multi_ack_detailed and no-done then
upload-pack is free to immediately send a PACK following its first
'ACK %s ready' message.  The upload-pack response actually winds
up being:

  ACK %s common
  ... (maybe more) ...
  ACK %s ready
  NAK
  ACK %s
  PACK.... the pack stream ....

For smart HTTP connections this saves one HTTP RPC, reducing
the overall latency for a trivial fetch.  For git:// and ssh://
a no-done option slightly reduces latency by removing one
server->client->server round-trip at the end of the common
ancestor negotiation.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Shawn O. Pearce 2011-03-14 17:59:40 -07:00 коммит произвёл Junio C Hamano
Родитель 49bee717f7
Коммит 3e63b21ace
1 изменённых файлов: 16 добавлений и 4 удалений

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@ -27,6 +27,7 @@ static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<
static unsigned long oldest_have;
static int multi_ack, nr_our_refs;
static int no_done;
static int use_thin_pack, use_ofs_delta, use_include_tag;
static int no_progress, daemon_mode;
static int shallow_nr;
@ -431,6 +432,7 @@ static int get_common_commits(void)
char last_hex[41];
int got_common = 0;
int got_other = 0;
int sent_ready = 0;
save_commit_buffer = 0;
@ -440,10 +442,17 @@ static int get_common_commits(void)
if (!len) {
if (multi_ack == 2 && got_common
&& !got_other && ok_to_give_up())
&& !got_other && ok_to_give_up()) {
sent_ready = 1;
packet_write(1, "ACK %s ready\n", last_hex);
}
if (have_obj.nr == 0 || multi_ack)
packet_write(1, "NAK\n");
if (no_done && sent_ready) {
packet_write(1, "ACK %s\n", last_hex);
return 0;
}
if (stateless_rpc)
exit(0);
got_common = 0;
@ -457,9 +466,10 @@ static int get_common_commits(void)
got_other = 1;
if (multi_ack && ok_to_give_up()) {
const char *hex = sha1_to_hex(sha1);
if (multi_ack == 2)
if (multi_ack == 2) {
sent_ready = 1;
packet_write(1, "ACK %s ready\n", hex);
else
} else
packet_write(1, "ACK %s continue\n", hex);
}
break;
@ -535,6 +545,8 @@ static void receive_needs(void)
multi_ack = 2;
else if (strstr(line+45, "multi_ack"))
multi_ack = 1;
if (strstr(line+45, "no-done"))
no_done = 1;
if (strstr(line+45, "thin-pack"))
use_thin_pack = 1;
if (strstr(line+45, "ofs-delta"))
@ -628,7 +640,7 @@ static int send_ref(const char *refname, const unsigned char *sha1, int flag, vo
{
static const char *capabilities = "multi_ack thin-pack side-band"
" side-band-64k ofs-delta shallow no-progress"
" include-tag multi_ack_detailed";
" include-tag multi_ack_detailed no-done";
struct object *o = parse_object(sha1);
if (!o)