git-send-pack: start parsing local/remote reference differences

Right now it just shows which refs it picks up, and whether they are
the same or changed on the remote end. Getting there..

diff --git a/send-pack.c b/send-pack.c
index 99cb84b..1c1b921 100644 (file)
--- a/send-pack.c
+++ b/send-pack.c
@@ -5,18 +5,73 @@ static const char send_pack_usage[] = "git-send-pack [--exec=other] destination
 
 static const char *exec = "git-receive-pack";
 
+struct ref {
+       struct ref *next;
+       unsigned char old_sha1[20];
+       unsigned char new_sha1[20];
+       char name[0];
+};
+
+static struct ref *ref_list = NULL;
+
+static int read_ref(const char *ref, unsigned char *sha1)
+{
+       int fd, ret;
+       static char pathname[PATH_MAX];
+       char buffer[60];
+       const char *git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
+
+       snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, ref);
+       fd = open(pathname, O_RDONLY);
+       if (fd < 0)
+               return -1;
+       ret = -1;
+       if (read(fd, buffer, sizeof(buffer)) >= 40)
+               ret = get_sha1_hex(buffer, sha1);
+       close(fd);
+       return ret;
+}
+
 static int send_pack(int in, int out)
 {
        for (;;) {
+               unsigned char old_sha1[20];
+               unsigned char new_sha1[20];
                static char buffer[1000];
+               char *name;
+               struct ref *n;
                int len;
 
                len = packet_read_line(in, buffer, sizeof(buffer));
-               if (len > 0) {
-                       write(2, buffer, len);
+               if (!len)
+                       break;
+               if (buffer[len-1] == '\n')
+                       buffer[--len] = 0;
+
+               if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
+                       die("protocol error: expected sha/ref, got '%s'", buffer);
+               name = buffer + 41;
+               if (read_ref(name, new_sha1) < 0) {
+                       fprintf(stderr, "no such local reference '%s'\n", name);
                        continue;
                }
-               break;
+               if (!has_sha1_file(old_sha1)) {
+                       fprintf(stderr, "remote '%s' points to object I don't have\n", name);
+                       continue;
+               }
+               if (!memcmp(old_sha1, new_sha1, 20)) {
+                       fprintf(stderr, "'%s' unchanged\n", name);
+               } else {
+                       char new_hex[60];
+                       strcpy(new_hex, sha1_to_hex(new_sha1));
+                       fprintf(stderr, "%s: updating from %s to %s\n", name, sha1_to_hex(old_sha1), new_hex);
+               }
+               n = xmalloc(sizeof(*n) + len - 40);
+               memcpy(n->old_sha1, old_sha1, 20);
+               memcpy(n->new_sha1, new_sha1, 20);
+               memcpy(n->name, buffer + 41, len - 40);
+               n->next = ref_list;
+               ref_list = n;
        }
        packet_flush(out);
        close(out);