clone-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4
   5 static const char clone_pack_usage[] =
   6 "git-clone-pack [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
   7 static const char *exec = "git-upload-pack";
   8
   9 static int quiet = 0;
  10
  11 static void clone_handshake(int fd[2], struct ref *ref)
  12 {
  13         unsigned char sha1[20];
  14
  15         while (ref) {
  16                 packet_write(fd[1], "want %s\n", sha1_to_hex(ref->old_sha1));
  17                 ref = ref->next;
  18         }
  19         packet_flush(fd[1]);
  20
  21         /* We don't have nuttin' */
  22         packet_write(fd[1], "done\n");
  23         if (get_ack(fd[0], sha1))
  24                 error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1));
  25 }
  26
  27 static int is_master(struct ref *ref)
  28 {
  29         return !strcmp(ref->name, "refs/heads/master");
  30 }
  31
  32 static void write_one_ref(struct ref *ref)
  33 {
  34         char *path = git_path("%s", ref->name);
  35         int fd;
  36         char *hex;
  37
  38         if (!strncmp(ref->name, "refs/", 5) &&
  39             check_ref_format(ref->name + 5)) {
  40                 error("refusing to create funny ref '%s' locally", ref->name);
  41                 return;
  42         }
  43
  44         if (safe_create_leading_directories(path))
  45                 die("unable to create leading directory for %s", ref->name);
  46         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
  47         if (fd < 0)
  48                 die("unable to create ref %s", ref->name);
  49         hex = sha1_to_hex(ref->old_sha1);
  50         hex[40] = '\n';
  51         if (write(fd, hex, 41) != 41)
  52                 die("unable to write ref %s", ref->name);
  53         close(fd);
  54 }
  55
  56 static void write_refs(struct ref *ref)
  57 {
  58         struct ref *head = NULL, *head_ptr, *master_ref;
  59         char *head_path;
  60
  61         /* Upload-pack must report HEAD first */
  62         if (!strcmp(ref->name, "HEAD")) {
  63                 head = ref;
  64                 ref = ref->next;
  65         }
  66         head_ptr = NULL;
  67         master_ref = NULL;
  68         while (ref) {
  69                 if (is_master(ref))
  70                         master_ref = ref;
  71                 if (head &&
  72                     !memcmp(ref->old_sha1, head->old_sha1, 20) &&
  73                     !strncmp(ref->name, "refs/heads/",11) &&
  74                     (!head_ptr || ref == master_ref))
  75                         head_ptr = ref;
  76
  77                 write_one_ref(ref);
  78                 ref = ref->next;
  79         }
  80         if (!head) {
  81                 fprintf(stderr, "No HEAD in remote.\n");
  82                 return;
  83         }
  84
  85         head_path = strdup(git_path("HEAD"));
  86         if (!head_ptr) {
  87                 /*
  88                  * If we had a master ref, and it wasn't HEAD, we need to undo the
  89                  * symlink, and write a standalone HEAD. Give a warning, because that's
  90                  * really really wrong.
  91                  */
  92                 if (master_ref) {
  93                         error("HEAD doesn't point to any refs! Making standalone HEAD");
  94                         unlink(head_path);
  95                 }
  96                 write_one_ref(head);
  97                 free(head_path);
  98                 return;
  99         }
 100
 101         /* We reset to the master branch if it's available */
 102         if (master_ref)
 103                 return;
 104
 105         fprintf(stderr, "Setting HEAD to %s\n", head_ptr->name);
 106
 107         /*
 108          * Uhhuh. Other end didn't have master. We start HEAD off with
 109          * the first branch with the same value.
 110          */
 111         if (create_symref(head_path, head_ptr->name) < 0)
 112                 die("unable to link HEAD to %s", head_ptr->name);
 113         free(head_path);
 114 }
 115
 116 static int clone_pack(int fd[2], int nr_match, char **match)
 117 {
 118         struct ref *refs;
 119         int status;
 120
 121         get_remote_heads(fd[0], &refs, nr_match, match, 1);
 122         if (!refs) {
 123                 packet_flush(fd[1]);
 124                 die("no matching remote head");
 125         }
 126         clone_handshake(fd, refs);
 127
 128         status = receive_keep_pack(fd, "git-clone-pack", quiet);
 129         if (!quiet)
 130                 fprintf(stderr, "\n");
 131
 132         if (!status) {
 133                 if (nr_match == 0)
 134                         write_refs(refs);
 135                 else
 136                         while (refs) {
 137                                 printf("%s %s\n",
 138                                        sha1_to_hex(refs->old_sha1),
 139                                        refs->name);
 140                                 refs = refs->next;
 141                         }
 142         }
 143         return status;
 144 }
 145
 146 int main(int argc, char **argv)
 147 {
 148         int i, ret, nr_heads;
 149         char *dest = NULL, **heads;
 150         int fd[2];
 151         pid_t pid;
 152
 153         setup_git_directory();
 154
 155         nr_heads = 0;
 156         heads = NULL;
 157         for (i = 1; i < argc; i++) {
 158                 char *arg = argv[i];
 159
 160                 if (*arg == '-') {
 161                         if (!strcmp("-q", arg)) {
 162                                 quiet = 1;
 163                                 continue;
 164                         }
 165                         if (!strncmp("--exec=", arg, 7)) {
 166                                 exec = arg + 7;
 167                                 continue;
 168                         }
 169                         usage(clone_pack_usage);
 170                 }
 171                 dest = arg;
 172                 heads = argv + i + 1;
 173                 nr_heads = argc - i - 1;
 174                 break;
 175         }
 176         if (!dest)
 177                 usage(clone_pack_usage);
 178         pid = git_connect(fd, dest, exec);
 179         if (pid < 0)
 180                 return 1;
 181         ret = clone_pack(fd, nr_heads, heads);
 182         close(fd[0]);
 183         close(fd[1]);
 184         finish_connect(pid);
 185         return ret;
 186 }