From 49bee717f7080f99d3405682cc43ad525dde0973 Mon Sep 17 00:00:00 2001
From: "Shawn O. Pearce" <spearce@spearce.org>
Date: Mon, 14 Mar 2011 16:48:39 -0700
Subject: [PATCH 1/2] upload-pack: More aggressively send 'ACK %s ready'
If a client is merely following the remote (and has not made any
new commits itself), all "have %s" lines sent by the client will be
common to the server. As all lines are common upload-pack never
calls ok_to_give_up() and does not compute if it has a good cut
point in the commit graph.
Without this computation the following client is going to send all
tagged commits, as these were determined to be COMMON_REF during the
initial advertisement, but the client does not parse their history
to transitively pass the COMMON flag and empty its queue of commits.
For git.git with 339 commit tags, it takes clients 11 rounds of
negotation to fully send all tagged commits and exhaust its queue
of things to send as common. This is pretty slow for a client that
has not done any local development activity.
Force computing ok_to_give_up() and send "ACK %s ready" at the end
of the current round if this round only contained common objects
and ok_to_give_up() was therefore not called. This may allow the
client to break early, avoiding transmission of the COMMON_REFs.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
upload-pack.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/upload-pack.c b/upload-pack.c
index b40a43f27d0..11c3849a79c 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -429,6 +429,8 @@ static int get_common_commits(void)
static char line[1000];
unsigned char sha1[20];
char last_hex[41];
+ int got_common = 0;
+ int got_other = 0;
save_commit_buffer = 0;
@@ -437,16 +439,22 @@ static int get_common_commits(void)
reset_timeout();
if (!len) {
+ if (multi_ack == 2 && got_common
+ && !got_other && ok_to_give_up())
+ packet_write(1, "ACK %s ready\n", last_hex);
if (have_obj.nr == 0 || multi_ack)
packet_write(1, "NAK\n");
if (stateless_rpc)
exit(0);
+ got_common = 0;
+ got_other = 0;
continue;
}
strip(line, len);
if (!prefixcmp(line, "have ")) {
switch (got_sha1(line+5, sha1)) {
case -1: /* they have what we do not */
+ got_other = 1;
if (multi_ack && ok_to_give_up()) {
const char *hex = sha1_to_hex(sha1);
if (multi_ack == 2)
@@ -456,6 +464,7 @@ static int get_common_commits(void)
}
break;
default:
+ got_common = 1;
memcpy(last_hex, sha1_to_hex(sha1), 41);
if (multi_ack == 2)
packet_write(1, "ACK %s common\n", last_hex);
From 3e63b21aced116badd30a279c479535449a63560 Mon Sep 17 00:00:00 2001
From: "Shawn O. Pearce" <spearce@spearce.org>
Date: Mon, 14 Mar 2011 17:59:40 -0700
Subject: [PATCH 2/2] 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>
---
upload-pack.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/upload-pack.c b/upload-pack.c
index 11c3849a79c..5924f6f988a 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -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)