support fetching into a shallow repository
A shallow commit is a commit which has parents, which in turn are
"grafted away", i.e. the commit appears as if it were a root.
Since these shallow commits should not be edited by the user, but
only by core git, they are recorded in the file $GIT_DIR/shallow.
A repository containing shallow commits is called shallow.
The advantage of a shallow repository is that even if the upstream
contains lots of history, your local (shallow) repository needs not
occupy much disk space.
The disadvantage is that you might miss a merge base when pulling
some remote branch.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/upload-pack.c b/upload-pack.c
index 7f7df2a..8dd6121 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -486,6 +486,7 @@
static void receive_needs(void)
{
+ struct object_array shallows = {0, 0, NULL};
static char line[1000];
int len;
@@ -495,8 +496,19 @@
len = packet_read_line(0, line, sizeof(line));
reset_timeout();
if (!len)
- return;
+ break;
+ if (!strncmp("shallow ", line, 8)) {
+ unsigned char sha1[20];
+ struct object *object;
+ if (get_sha1(line + 8, sha1))
+ die("invalid shallow line: %s", line);
+ object = parse_object(sha1);
+ if (!object)
+ die("did not find object for %s", line);
+ add_object_array(object, NULL, &shallows);
+ continue;
+ }
if (strncmp("want ", line, 5) ||
get_sha1_hex(line+5, sha1_buf))
die("git-upload-pack: protocol error, "
@@ -528,11 +540,17 @@
add_object_array(o, NULL, &want_obj);
}
}
+ if (shallows.nr > 0) {
+ int i;
+ for (i = 0; i < shallows.nr; i++)
+ register_shallow(shallows.objects[i].item->sha1);
+ }
}
static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
{
- static const char *capabilities = "multi_ack thin-pack side-band side-band-64k ofs-delta";
+ static const char *capabilities = "multi_ack thin-pack side-band"
+ " side-band-64k ofs-delta shallow";
struct object *o = parse_object(sha1);
if (!o)
