Fetch from a packed repository on dumb servers.

Implement fetching from a packed repository over http/https
using the dumb server support files.

I consider some parts of the logic should be in a separate C
program, but it appears to work with my simple tests.  I have
backburnered it for a bit too long for my liking, so let's throw
it out in the open and see what happens.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 63 insertions, 0 deletions

diff --git a/missing-revs.c b/missing-revs.c
new file mode 100644
index 0000000000..afe41e33d4
--- /dev/null
+++ b/missing-revs.c
@@ -0,0 +1,63 @@
+#include "cache.h"
+#include "rev-cache.h"
+
+static const char missing_revs_usage[] =
+"git-missing-revs <rev-cache-file> <want-sha1>...";
+
+#define REV_WANT 01
+#define REV_HAVE 02
+
+static void process(struct rev_cache *head_list)
+{
+	while (head_list) {
+		struct rev_cache *rc = head_list;
+		struct rev_list_elem *e;
+		head_list = rc->head_list;
+		rc->head_list = NULL;
+		if (has_sha1_file(rc->sha1)) {
+			rc->work |= REV_HAVE;
+			continue;
+		}
+		if (rc->work & (REV_WANT|REV_HAVE))
+			continue;
+		rc->work |= REV_WANT;
+		printf("%s\n", sha1_to_hex(rc->sha1));
+		for (e = rc->parents; e; e = e->next) {
+			if (e->ri->work & REV_HAVE)
+				continue;
+			e->ri->head_list = head_list;
+			head_list = e->ri;
+		}
+	}
+}
+
+int main(int ac, char **av)
+{
+	const char *rev_cache_file;
+	struct rev_cache *head_list = NULL;
+	int i;
+
+	if (ac < 3)
+		usage(missing_revs_usage);
+	rev_cache_file = av[1];
+	read_rev_cache(rev_cache_file, NULL, 0);
+	for (i = 2; i < ac; i++) {
+		unsigned char sha1[20];
+		int pos;
+		struct rev_cache *rc;
+		if (get_sha1_hex(av[i], sha1))
+			die("%s: not an SHA1", av[i]);
+		if ((pos = find_rev_cache(sha1)) < 0) {
+			/* We could be asked for tags, which would not
+			 * appear in the rev-cache.
+			 */
+			puts(av[i]);
+			continue;
+		}
+		rc = rev_cache[pos];
+		rc->head_list = head_list;
+		head_list = rc;
+	}
+	process(head_list);
+	return 0;
+}