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