git-fetch-pack: avoid unnecessary zero packing

diff --git a/fetch-pack.c b/fetch-pack.c
index 65e007639ac744c3f354f71c157a85c5d6477d49..459736909cb3b16348b5dab893461e41b98f89aa 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -4,11 +4,15 @@
 #include <sys/wait.h>
 
 static int quiet;
-static const char fetch_pack_usage[] = "git-fetch-pack [-q] [--exec=upload-pack] [host:]directory [heads]* < mycommitlist";
+static int verbose;
+static const char fetch_pack_usage[] =
+"git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
 static const char *exec = "git-upload-pack";
 
-static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote)
+static int find_common(int fd[2], unsigned char *result_sha1,
+                      struct ref *refs)
 {
+       int fetching;
        static char line[1000];
        int count = 0, flushes = 0, retval;
        FILE *revs;
@@ -16,8 +20,20 @@ static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *rem
        revs = popen("git-rev-list $(git-rev-parse --all)", "r");
        if (!revs)
                die("unable to run 'git-rev-list'");
-       packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
+
+       fetching = 0;
+       for ( ; refs ; refs = refs->next) {
+               unsigned char *remote = refs->old_sha1;
+               unsigned char *local = refs->new_sha1;
+
+               if (!memcmp(remote, local, 20))
+                       continue;
+               packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
+               fetching++;
+       }
        packet_flush(fd[1]);
+       if (!fetching)
+               return 1;
        flushes = 1;
        retval = -1;
        while (fgets(line, sizeof(line), revs) != NULL) {
@@ -25,6 +41,8 @@ static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *rem
                if (get_sha1_hex(line, sha1))
                        die("git-fetch-pack: expected object name, got crud");
                packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
+               if (verbose)
+                       fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
                if (!(31 & ++count)) {
                        packet_flush(fd[1]);
                        flushes++;
@@ -38,6 +56,8 @@ static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *rem
                        if (get_ack(fd[0], result_sha1)) {
                                flushes = 0;
                                retval = 0;
+                               if (verbose)
+                                       fprintf(stderr, "got ack\n");
                                break;
                        }
                        flushes--;
@@ -45,19 +65,48 @@ static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *rem
        }
        pclose(revs);
        packet_write(fd[1], "done\n");
+       if (verbose)
+               fprintf(stderr, "done\n");
        while (flushes) {
                flushes--;
-               if (get_ack(fd[0], result_sha1))
+               if (get_ack(fd[0], result_sha1)) {
+                       if (verbose)
+                               fprintf(stderr, "got ack\n");
                        return 0;
+               }
+       }
+       return retval;
+}
+
+static int everything_local(struct ref *refs)
+{
+       int retval;
+
+       for (retval = 1; refs ; refs = refs->next) {
+               const unsigned char *remote = refs->old_sha1;
+               unsigned char local[20];
+
+               if (read_ref(git_path("%s", refs->name), local) < 0 ||
+                   memcmp(remote, local, 20)) {
+                       retval = 0;
+                       if (!verbose)
+                               continue;
+                       fprintf(stderr,
+                               "want %s (%s)\n", sha1_to_hex(remote),
+                               refs->name);
+                       continue;
+               }
+
+               memcpy(refs->new_sha1, local, 20);
+               if (!verbose)
+                       continue;
+               fprintf(stderr,
+                       "already have %s (%s)\n", sha1_to_hex(remote),
+                       refs->name);
        }
        return retval;
 }
 
-/*
- * Eventually we'll want to be able to fetch multiple heads.
- *
- * Right now we'll just require a single match.
- */
 static int fetch_pack(int fd[2], int nr_match, char **match)
 {
        struct ref *ref;
@@ -65,17 +114,17 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
        int status;
        pid_t pid;
 
-       get_remote_heads(fd[0], &ref, nr_match, match);
+       get_remote_heads(fd[0], &ref, nr_match, match, 1);
        if (!ref) {
                packet_flush(fd[1]);
                die("no matching remote head");
        }
-       if (ref->next) {
+       if (everything_local(ref)) {
                packet_flush(fd[1]);
-               die("multiple remote heads");
+               goto all_done;
        }
-       if (find_common(fd, sha1, ref->old_sha1) < 0)
-               die("git-fetch-pack: no common commits");
+       if (find_common(fd, sha1, ref) < 0)
+               fprintf(stderr, "warning: no common commits\n");
        pid = fork();
        if (pid < 0)
                die("git-fetch-pack: unable to fork off git-unpack-objects");
@@ -97,7 +146,12 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
                int code = WEXITSTATUS(status);
                if (code)
                        die("git-unpack-objects died with error code %d", code);
-               puts(sha1_to_hex(ref->old_sha1));
+all_done:
+               while (ref) {
+                       printf("%s %s\n",
+                              sha1_to_hex(ref->old_sha1), ref->name);
+                       ref = ref->next;
+               }
                return 0;
        }
        if (WIFSIGNALED(status)) {
@@ -124,6 +178,14 @@ int main(int argc, char **argv)
                                exec = arg + 7;
                                continue;
                        }
+                       if (!strcmp("-q", arg)) {
+                               quiet = 1;
+                               continue;
+                       }
+                       if (!strcmp("-v", arg)) {
+                               verbose = 1;
+                               continue;
+                       }
                        usage(fetch_pack_usage);
                }
                dest = arg;