Subject: [PATCH] git-fetch-pack: Do not use git-rev-list

The code used to call git-rev-list to enumerate the local revisions.
A disadvantage of that method was that git-rev-list, lacking a
control apart from the command line, would happily enumerate
ancestors of acknowledged common commits, which was just taking
unnecessary bandwidth.

Therefore, do not use git-rev-list on the fetching side, but rather
construct the list on the go. Send the revisions starting from the
local heads, ignoring the revisions known to be common.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Johannes Schindelin 2005-10-28 04:46:27 +02:00 committed by Junio C Hamano
parent 7d8b7c21c9
commit 23d61f8343

View file

@ -13,18 +13,130 @@ static const char fetch_pack_usage[] =
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;
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];
static char rev_command[1024];
int count = 0, flushes = 0, retval, rev_command_len;
FILE *revs;
int count = 0, flushes = 0, retval;
const unsigned char *sha1;
for_each_ref(rev_list_insert_ref);
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;
@ -42,25 +154,18 @@ static int find_common(int fd[2], unsigned char *result_sha1,
*/
if (((o = lookup_object(remote)) != NULL) &&
(o->flags & COMPLETE)) {
struct commit_list *p;
struct commit *commit =
(struct commit *) (o = deref_tag(o));
if (!o)
goto repair;
if (o->type != commit_type)
continue;
p = commit->parents;
while (p &&
rev_command_len + 44 < sizeof(rev_command)) {
snprintf(rev_command + rev_command_len, 44,
" ^%s",
sha1_to_hex(p->item->object.sha1));
rev_command_len += 43;
p = p->next;
o = deref_tag(o);
if (o->type == commit_type) {
struct commit *commit = (struct commit *)o;
rev_list_push(commit, COMMON_REF | SEEN);
mark_common(commit, 1, 1);
}
continue;
}
repair:
packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
fetching++;
}
@ -68,16 +173,9 @@ static int find_common(int fd[2], unsigned char *result_sha1,
if (!fetching)
return 1;
revs = popen(rev_command, "r");
if (!revs)
die("unable to run 'git-rev-list'");
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));
@ -101,10 +199,12 @@ static int find_common(int fd[2], unsigned char *result_sha1,
flushes--;
}
}
pclose(revs);
packet_write(fd[1], "done\n");
if (verbose)
fprintf(stderr, "done\n");
if (retval != 0)
flushes++;
while (flushes) {
flushes--;
if (get_ack(fd[0], result_sha1)) {