[PATCH] Do not send "want" lines for complete objects

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Oct 19, 2005, 22:07 UTC
Message-ID: <Pine.LNX.4.63.0510200004290.7689@wbgn013.biozentrum.uni-wuerzburg.de>

It was all good and well to check if all remote refs are complete (local refs or descendants thereof), but we can just as easily use the same information to avoid sending "want" lines just for the complete objects in the case that not all remote refs are complete (or their names differ).

Also, git-fetch-pack does not have to ask for descendants of remote refs which are complete (for now, git-rev-list is told to ignore only the first parent). That change also eliminates a code path where a popen()ed handle was not pclose()ed.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>

---

	With this patch, in a particular setup, git-fetch got 805 objects 
	instead of 8404, i.e. 10 times less! This setup involves 691 
	tags...

	NOTE: I'd rather have git-rev-list circumvented, so that 
	descendants of ack'ed objects are not sent via "have" lines.

	2nd NOTE: If this patch reminds you of my "has_ref()" patch: Yes,
	it is the next generation of that idea.

 fetch-pack.c |   33 +++++++++++++++++++++++++--------
 1 files changed, 25 insertions(+), 8 deletions(-)

applies-to: f76de7f266b0b7feb38c73c7ccb635d6da18a582 f22af070becd6546eeff44895769b8299a6ddb5e

diff --git a/fetch-pack.c b/fetch-pack.c
index 969e72a..9dfd072 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -12,31 +12,49 @@ static const char fetch_pack_usage[] =
 "git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
 static const char *exec = "git-upload-pack";
 
+#define COMPLETE	(1U << 0)
+
 static int find_common(int fd[2], unsigned char *result_sha1,
 		       struct ref *refs)
 {
 	int fetching;
 	static char line[1000];
-	int count = 0, flushes = 0, retval;
+	static char rev_command[1024];
+	int count = 0, flushes = 0, retval, rev_command_len;
 	FILE *revs;
 
-	revs = popen("git-rev-list $(git-rev-parse --all)", "r");
-	if (!revs)
-		die("unable to run 'git-rev-list'");
-
+	strcpy(rev_command, "git-rev-list $(git-rev-parse --all)");
+	rev_command_len = strlen(rev_command);
 	fetching = 0;
 	for ( ; refs ; refs = refs->next) {
 		unsigned char *remote = refs->old_sha1;
-		unsigned char *local = refs->new_sha1;
 
-		if (!memcmp(remote, local, 20))
+		/*
+		   If that object is complete (i.e. it is a descendant of a
+		   local ref), we don't want it, nor its descendants.
+		*/
+		if (has_sha1_file(remote)
+				&& parse_object(remote)->flags & COMPLETE) {
+			if (rev_command_len + 44 < sizeof(rev_command)) {
+				snprintf(rev_command + rev_command_len, 44,
+					" ^%s^", sha1_to_hex(remote));
+				rev_command_len += 43;
+			}
+
 			continue;
+		}
+
 		packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
 		fetching++;
 	}
 	packet_flush(fd[1]);
 	if (!fetching)
 		return 1;
+
+	revs = popen(rev_command, "r");
+	if (!revs)
+		die("unable to run 'git-rev-list'");
+
 	flushes = 1;
 	retval = -1;
 	while (fgets(line, sizeof(line), revs) != NULL) {
@@ -81,7 +99,6 @@ static int find_common(int fd[2], unsign
 	return retval;
 }
 
-#define COMPLETE	(1U << 0)
 static struct commit_list *complete = NULL;
 
 static int mark_complete(const char *path, const unsigned char *sha1)
---
0.99.8.GIT