1 files changed, 234 insertions, 39 deletions

diff --git a/fetch-pack.c b/fetch-pack.c
index 969e72a..3df9911 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -12,41 +12,168 @@ 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)
+#define COMMON		(1U << 1)
+#define COMMON_REF	(1U << 2)
+#define SEEN		(1U << 3)
+#define POPPED		(1U << 4)
+
+static struct commit_list *rev_list = NULL;
+static int non_common_revs = 0, multi_ack = 0;
+
+static void rev_list_push(struct commit *commit, int mark)
+{
+	if (!(commit->object.flags & mark)) {
+		commit->object.flags |= mark;
+
+		if (!(commit->object.parsed))
+			parse_commit(commit);
+
+		insert_by_date(commit, &rev_list);
+
+		if (!(commit->object.flags & COMMON))
+			non_common_revs++;
+	}
+}
+
+static int rev_list_insert_ref(const char *path, const unsigned char *sha1)
+{
+	struct object *o = deref_tag(parse_object(sha1));
+
+	if (o->type == commit_type)
+		rev_list_push((struct commit *)o, SEEN);
+
+	return 0;
+}
+
+/*
+   This function marks a rev and its ancestors as common.
+   In some cases, it is desirable to mark only the ancestors (for example
+   when only the server does not yet know that they are common).
+*/
+
+static void mark_common(struct commit *commit,
+		int ancestors_only, int dont_parse)
+{
+	if (commit != NULL && !(commit->object.flags & COMMON)) {
+		struct object *o = (struct object *)commit;
+
+		if (!ancestors_only)
+			o->flags |= COMMON;
+
+		if (!(o->flags & SEEN))
+			rev_list_push(commit, SEEN);
+		else {
+			struct commit_list *parents;
+
+			if (!ancestors_only && !(o->flags & POPPED))
+				non_common_revs--;
+			if (!o->parsed && !dont_parse)
+				parse_commit(commit);
+
+			for (parents = commit->parents;
+					parents;
+					parents = parents->next)
+				mark_common(parents->item, 0, dont_parse);
+		}
+	}
+}
+
+/*
+  Get the next rev to send, ignoring the common.
+*/
+
+static const unsigned char* get_rev()
+{
+	struct commit *commit = NULL;
+
+	while (commit == NULL) {
+		unsigned int mark;
+		struct commit_list* parents;
+
+		if (rev_list == NULL || non_common_revs == 0)
+			return NULL;
+
+		commit = rev_list->item;
+		if (!(commit->object.parsed))
+			parse_commit(commit);
+		commit->object.flags |= POPPED;
+		if (!(commit->object.flags & COMMON))
+			non_common_revs--;
+	
+		parents = commit->parents;
+
+		if (commit->object.flags & COMMON) {
+			/* do not send "have", and ignore ancestors */
+			commit = NULL;
+			mark = COMMON | SEEN;
+		} else if (commit->object.flags & COMMON_REF)
+			/* send "have", and ignore ancestors */
+			mark = COMMON | SEEN;
+		else
+			/* send "have", also for its ancestors */
+			mark = SEEN;
+
+		while (parents) {
+			if (!(parents->item->object.flags & SEEN))
+				rev_list_push(parents->item, mark);
+			if (mark & COMMON)
+				mark_common(parents->item, 1, 0);
+			parents = parents->next;
+		}
+
+		rev_list = rev_list->next;
+	}
+
+	return commit->object.sha1;
+}
+
 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;
-	FILE *revs;
+	const unsigned char *sha1;
 
-	revs = popen("git-rev-list $(git-rev-parse --all)", "r");
-	if (!revs)
-		die("unable to run 'git-rev-list'");
+	for_each_ref(rev_list_insert_ref);
 
 	fetching = 0;
 	for ( ; refs ; refs = refs->next) {
 		unsigned char *remote = refs->old_sha1;
-		unsigned char *local = refs->new_sha1;
+		struct object *o;
 
-		if (!memcmp(remote, local, 20))
+		/*
+		 * If that object is complete (i.e. it is an ancestor of a
+		 * local ref), we tell them we have it but do not have to
+		 * tell them about its ancestors, which they already know
+		 * about.
+		 *
+		 * We use lookup_object here because we are only
+		 * interested in the case we *know* the object is
+		 * reachable and we have already scanned it.
+		 */
+		if (((o = lookup_object(remote)) != NULL) &&
+				(o->flags & COMPLETE)) {
 			continue;
-		packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
+		}
+
+		packet_write(fd[1], "want %s%s\n", sha1_to_hex(remote),
+			multi_ack ? " multi_ack" : "");
 		fetching++;
 	}
 	packet_flush(fd[1]);
 	if (!fetching)
 		return 1;
-	flushes = 1;
+
+	flushes = 0;
 	retval = -1;
-	while (fgets(line, sizeof(line), revs) != NULL) {
-		unsigned char sha1[20];
-		if (get_sha1_hex(line, sha1))
-			die("git-fetch-pack: expected object name, got crud");
+	while ((sha1 = get_rev())) {
 		packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
 		if (verbose)
 			fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 		if (!(31 & ++count)) {
+			int ack;
+
 			packet_flush(fd[1]);
 			flushes++;
 
@@ -56,32 +183,51 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 			 */
 			if (count == 32)
 				continue;
-			if (get_ack(fd[0], result_sha1)) {
-				flushes = 0;
-				retval = 0;
-				if (verbose)
-					fprintf(stderr, "got ack\n");
-				break;
-			}
+
+			do {
+				ack = get_ack(fd[0], result_sha1);
+				if (verbose && ack)
+					fprintf(stderr, "got ack %d %s\n", ack,
+							sha1_to_hex(result_sha1));
+				if (ack == 1) {
+					flushes = 0;
+					multi_ack = 0;
+					retval = 0;
+					goto done;
+				} else if (ack == 2) {
+					struct commit *commit =
+						lookup_commit(result_sha1);
+					mark_common(commit, 0, 1);
+					retval = 0;
+				}
+			} while (ack);
 			flushes--;
 		}
 	}
-	pclose(revs);
+done:
 	packet_write(fd[1], "done\n");
 	if (verbose)
 		fprintf(stderr, "done\n");
-	while (flushes) {
-		flushes--;
-		if (get_ack(fd[0], result_sha1)) {
+	if (retval != 0) {
+		multi_ack = 0;
+		flushes++;
+	}
+	while (flushes || multi_ack) {
+		int ack = get_ack(fd[0], result_sha1);
+		if (ack) {
 			if (verbose)
-				fprintf(stderr, "got ack\n");
-			return 0;
+				fprintf(stderr, "got ack (%d) %s\n", ack,
+					sha1_to_hex(result_sha1));
+			if (ack == 1)
+				return 0;
+			multi_ack = 1;
+			continue;
 		}
+		flushes--;
 	}
 	return retval;
 }
 
-#define COMPLETE	(1U << 0)
 static struct commit_list *complete = NULL;
 
 static int mark_complete(const char *path, const unsigned char *sha1)
@@ -89,10 +235,13 @@ static int mark_complete(const char *path, const unsigned char *sha1)
 	struct object *o = parse_object(sha1);
 
 	while (o && o->type == tag_type) {
+		struct tag *t = (struct tag *) o;
+		if (!t->tagged)
+			break; /* broken repository */
 		o->flags |= COMPLETE;
-		o = parse_object(((struct tag *)o)->tagged->sha1);
+		o = parse_object(t->tagged->sha1);
 	}
-	if (o->type == commit_type) {
+	if (o && o->type == commit_type) {
 		struct commit *commit = (struct commit *)o;
 		commit->object.flags |= COMPLETE;
 		insert_by_date(commit, &complete);
@@ -110,7 +259,29 @@ static void mark_recent_complete_commits(unsigned long cutoff)
 	}
 }
 
-static int everything_local(struct ref *refs)
+static void filter_refs(struct ref **refs, int nr_match, char **match)
+{
+	struct ref *prev, *current, *next;
+
+	if (!nr_match)
+		return;
+
+	for (prev = NULL, current = *refs; current; current = next) {
+		next = current->next;
+		if ((!memcmp(current->name, "refs/", 5) &&
+					check_ref_format(current->name + 5)) ||
+				!path_match(current->name, nr_match, match)) {
+			if (prev == NULL)
+				*refs = next;
+			else
+				prev->next = next;
+			free(current);
+		} else
+			prev = current;
+	}
+}
+
+static int everything_local(struct ref **refs, int nr_match, char **match)
 {
 	struct ref *ref;
 	int retval;
@@ -119,7 +290,7 @@ static int everything_local(struct ref *refs)
 	track_object_refs = 0;
 	save_commit_buffer = 0;
 
-	for (ref = refs; ref; ref = ref->next) {
+	for (ref = *refs; ref; ref = ref->next) {
 		struct object *o;
 
 		o = parse_object(ref->old_sha1);
@@ -141,28 +312,47 @@ static int everything_local(struct ref *refs)
 	if (cutoff)
 		mark_recent_complete_commits(cutoff);
 
-	for (retval = 1; refs ; refs = refs->next) {
-		const unsigned char *remote = refs->old_sha1;
+	/*
+	 * Mark all complete remote refs as common refs.
+	 * Don't mark them common yet; the server has to be told so first.
+	 */
+	for (ref = *refs; ref; ref = ref->next) {
+		struct object *o = deref_tag(lookup_object(ref->old_sha1));
+
+		if (!o || o->type != commit_type || !(o->flags & COMPLETE))
+			continue;
+
+		if (!(o->flags & SEEN)) {
+			rev_list_push((struct commit *)o, COMMON_REF | SEEN);
+
+			mark_common((struct commit *)o, 1, 1);
+		}
+	}
+
+	filter_refs(refs, nr_match, match);
+
+	for (retval = 1, ref = *refs; ref ; ref = ref->next) {
+		const unsigned char *remote = ref->old_sha1;
 		unsigned char local[20];
 		struct object *o;
 
-		o = parse_object(remote);
+		o = lookup_object(remote);
 		if (!o || !(o->flags & COMPLETE)) {
 			retval = 0;
 			if (!verbose)
 				continue;
 			fprintf(stderr,
 				"want %s (%s)\n", sha1_to_hex(remote),
-				refs->name);
+				ref->name);
 			continue;
 		}
 
-		memcpy(refs->new_sha1, local, 20);
+		memcpy(ref->new_sha1, local, 20);
 		if (!verbose)
 			continue;
 		fprintf(stderr,
 			"already have %s (%s)\n", sha1_to_hex(remote),
-			refs->name);
+			ref->name);
 	}
 	return retval;
 }
@@ -174,12 +364,17 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
 	int status;
 	pid_t pid;
 
-	get_remote_heads(fd[0], &ref, nr_match, match, 1);
+	get_remote_heads(fd[0], &ref, 0, NULL, 0);
+	if (server_supports("multi_ack")) {
+		if (verbose)
+			fprintf(stderr, "Server supports multi_ack\n");
+		multi_ack = 1;
+	}
 	if (!ref) {
 		packet_flush(fd[1]);
 		die("no matching remote head");
 	}
-	if (everything_local(ref)) {
+	if (everything_local(&ref, nr_match, match)) {
 		packet_flush(fd[1]);
 		goto all_done;
 	}