Re: [PATCH 3/4] Make git-fetch follow tags we already have objects for sooner

["Shawn O. Pearce" <spearce@spearce.org>]

Daniel Barkalow <barkalow@iabervon.org> wrote:
> On Fri, 29 Feb 2008, Shawn O. Pearce wrote:
> 
> > Junio C Hamano <gitster@pobox.com> wrote:
> > > This is cute.  Obviously some tests need to be adjusted for this
> > > change, though.
> > 
> > I'll take a look at the current tests this weekend and see what
> > needs to be adjusted, if anything.  I'd also like to get a few
> > tests written for this, so we are certain the optimizations are
> > kicking in when they are supposed to be.
> 
> I'd be really grateful if you came up with a good general strategy for 
> testing that we're not doing too much work in fetching, because clone has 
> optimizations that I need to test in a similar way, and I haven't been 
> able to think of anything not horribly intrusive.

Is this "horribly intrusive" ?

We can test it with something like this:

  $ GIT_DEBUG_SEND_PACK=1 git fetch 3>UPLOAD_LOG
  $ cat UPLOAD_LOG
  #S
  want 8e10cf4e007ad7e003463c30c34b1050b039db78 multi_ack side-band-64k thin-pack ofs-delta
  want ddfa4a33562179aca1ace2bcc662244a17d0b503
  #E
  #S
  want 3253df4d1cf6fb138b52b1938473bcfec1483223 multi_ack side-band-64k thin-pack ofs-delta
  #E

Notice we made two connections, wanting 2 things and then later
only wanting 1 thing.  Tag auto-following.  :-)

diff --git a/upload-pack.c b/upload-pack.c
index b26d053..4e14020 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -444,7 +444,10 @@ static void receive_needs(void)
 	struct object_array shallows = {0, 0, NULL};
 	static char line[1000];
 	int len, depth = 0;
+	int debug_needs = !!getenv("GIT_DEBUG_SEND_PACK");
 
+	if (debug_needs)
+		write_in_full(3, "#S\n", 3);
 	for (;;) {
 		struct object *o;
 		unsigned char sha1_buf[20];
@@ -452,6 +455,8 @@ static void receive_needs(void)
 		reset_timeout();
 		if (!len)
 			break;
+		if (debug_needs)
+			write_in_full(3, line, len);
 
 		if (!prefixcmp(line, "shallow ")) {
 			unsigned char sha1[20];
@@ -507,6 +512,8 @@ static void receive_needs(void)
 			add_object_array(o, NULL, &want_obj);
 		}
 	}
+	if (debug_needs)
+		write_in_full(3, "#E\n", 3);
 	if (depth == 0 && shallows.nr == 0)
 		return;
 	if (depth > 0) {

-- 
Shawn.