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* [PATCH 1/2] refs_from_alternate: helper to use refs from alternates
@ 2011-03-11 20:51 Junio C Hamano
  2011-03-11 20:51 ` [PATCH 2/2] fetch-pack: objects in our alternates are available to us Junio C Hamano
  2011-03-11 23:08 ` [PATCH 1/2] refs_from_alternate: helper to use refs from alternates Johannes Sixt
  0 siblings, 2 replies; 6+ messages in thread
From: Junio C Hamano @ 2011-03-11 20:51 UTC (permalink / raw)
  To: git; +Cc: Shawn O. Pearce

The receiving end of "git push" advertises the objects that the repository
itself does not use, but are at the tips of refs in other repositories
whose object databases are used as alternates for it. This helps it avoid
having to receive (and the pusher having to send) objects that are already
available to the receiving repository via the alternates mechanism.

Tweak the helper function that implements this feature, and move it to
transport.[ch] for future reuse by other programs.

The additional test demonstrates how this optimization is helping "git push",
and "git fetch" is ignorant about it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/receive-pack.c           |   35 ++------------------
 t/t5501-fetch-push-alternates.sh |   66 ++++++++++++++++++++++++++++++++++++++
 transport.c                      |   34 +++++++++++++++++++
 transport.h                      |    3 ++
 4 files changed, 106 insertions(+), 32 deletions(-)
 create mode 100755 t/t5501-fetch-push-alternates.sh

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 760817d..a5b5fc2 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -731,43 +731,14 @@ static int delete_only(struct command *commands)
 	return 1;
 }
 
-static int add_refs_from_alternate(struct alternate_object_database *e, void *unused)
+static void add_one_alternate_ref(const struct ref *ref, void *unused)
 {
-	char *other;
-	size_t len;
-	struct remote *remote;
-	struct transport *transport;
-	const struct ref *extra;
-
-	e->name[-1] = '\0';
-	other = xstrdup(make_absolute_path(e->base));
-	e->name[-1] = '/';
-	len = strlen(other);
-
-	while (other[len-1] == '/')
-		other[--len] = '\0';
-	if (len < 8 || memcmp(other + len - 8, "/objects", 8))
-		return 0;
-	/* Is this a git repository with refs? */
-	memcpy(other + len - 8, "/refs", 6);
-	if (!is_directory(other))
-		return 0;
-	other[len - 8] = '\0';
-	remote = remote_get(other);
-	transport = transport_get(remote, other);
-	for (extra = transport_get_remote_refs(transport);
-	     extra;
-	     extra = extra->next) {
-		add_extra_ref(".have", extra->old_sha1, 0);
-	}
-	transport_disconnect(transport);
-	free(other);
-	return 0;
+	add_extra_ref(".have", ref->old_sha1, 0);
 }
 
 static void add_alternate_refs(void)
 {
-	foreach_alt_odb(add_refs_from_alternate, NULL);
+	foreach_alt_odb(refs_from_alternate_cb, add_one_alternate_ref);
 }
 
 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
diff --git a/t/t5501-fetch-push-alternates.sh b/t/t5501-fetch-push-alternates.sh
new file mode 100755
index 0000000..564ef7c
--- /dev/null
+++ b/t/t5501-fetch-push-alternates.sh
@@ -0,0 +1,66 @@
+#!/bin/sh
+
+test_description='fetch/push involving alternates'
+. ./test-lib.sh
+
+count_objects () {
+	(
+		echo 0 &&
+		git count-objects -v |
+		sed -n -e 's/^count: \(.*\)/\1 +/p' \
+		    -e 's/^in-pack: \(.*\)/\1 +/p' &&
+		echo p
+	) | dc
+}
+
+
+test_expect_success setup '
+	(
+		git init original &&
+		cd original &&
+		i=0 &&
+		while test $i -le 100
+		do
+			echo "$i" >count &&
+			git add count &&
+			git commit -m "$i" || exit
+			i=$(($i + 1))
+		done
+	) &&
+	(
+		git clone --reference=original "file:///$(pwd)/original" one &&
+		cd one &&
+		echo Z >count &&
+		git add count &&
+		git commit -m Z &&
+		count_objects >../one.count
+	) &&
+	A=$(pwd)/original/.git/objects &&
+	git init receiver &&
+	echo "$A" >receiver/.git/objects/info/alternates &&
+	git init fetcher &&
+	echo "$A" >fetcher/.git/objects/info/alternates
+'
+
+test_expect_success 'pushing into a repository with the same alternate' '
+	(
+		cd one &&
+		git push ../receiver master:refs/heads/it
+	) &&
+	(
+		cd receiver &&
+		count_objects >../receiver.count
+	) &&
+	test_cmp one.count receiver.count
+'
+
+test_expect_failure 'fetching from a repository with the same alternate' '
+	(
+		cd fetcher &&
+		git fetch ../one master:refs/heads/it &&
+		count_objects >../fetcher.count
+	) &&
+	test_cmp one.count fetcher.count
+'
+
+test_done
diff --git a/transport.c b/transport.c
index 0078660..3dfbc6a 100644
--- a/transport.c
+++ b/transport.c
@@ -1189,3 +1189,37 @@ char *transport_anonymize_url(const char *url)
 literal_copy:
 	return xstrdup(url);
 }
+
+int refs_from_alternate_cb(struct alternate_object_database *e, void *cb)
+{
+	char *other;
+	size_t len;
+	struct remote *remote;
+	struct transport *transport;
+	const struct ref *extra;
+	alternate_ref_fn *ref_fn = cb;
+
+	e->name[-1] = '\0';
+	other = xstrdup(make_absolute_path(e->base));
+	e->name[-1] = '/';
+	len = strlen(other);
+
+	while (other[len-1] == '/')
+		other[--len] = '\0';
+	if (len < 8 || memcmp(other + len - 8, "/objects", 8))
+		return 0;
+	/* Is this a git repository with refs? */
+	memcpy(other + len - 8, "/refs", 6);
+	if (!is_directory(other))
+		return 0;
+	other[len - 8] = '\0';
+	remote = remote_get(other);
+	transport = transport_get(remote, other);
+	for (extra = transport_get_remote_refs(transport);
+	     extra;
+	     extra = extra->next)
+		ref_fn(extra, NULL);
+	transport_disconnect(transport);
+	free(other);
+	return 0;
+}
diff --git a/transport.h b/transport.h
index e803c0e..efb1968 100644
--- a/transport.h
+++ b/transport.h
@@ -166,4 +166,7 @@ int transport_refs_pushed(struct ref *ref);
 void transport_print_push_status(const char *dest, struct ref *refs,
 		  int verbose, int porcelain, int *nonfastforward);
 
+typedef void alternate_ref_fn(const struct ref *, void *);
+extern int refs_from_alternate_cb(struct alternate_object_database *e, void *cb);
+
 #endif
-- 
1.7.4.1.404.g62d316

^ permalink raw reply related	[flat|nested] 6+ messages in thread
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Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-03-11 20:51 [PATCH 1/2] refs_from_alternate: helper to use refs from alternates Junio C Hamano
2011-03-11 20:51 ` [PATCH 2/2] fetch-pack: objects in our alternates are available to us Junio C Hamano
2011-03-15  1:57   ` Shawn Pearce
2011-03-11 23:08 ` [PATCH 1/2] refs_from_alternate: helper to use refs from alternates Johannes Sixt
2011-03-11 23:15   ` Junio C Hamano
2011-03-11 23:32     ` Junio C Hamano

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