clone-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include <sys/wait.h>
   5
   6 static int quiet;
   7 static int keep_pack;
   8 static const char clone_pack_usage[] =
   9 "git-clone-pack [-q] [--keep] [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
  10 static const char *exec = "git-upload-pack";
  11
  12 static void clone_handshake(int fd[2], struct ref *ref)
  13 {
  14         unsigned char sha1[20];
  15
  16         while (ref) {
  17                 packet_write(fd[1], "want %s\n", sha1_to_hex(ref->old_sha1));
  18                 ref = ref->next;
  19         }
  20         packet_flush(fd[1]);
  21
  22         /* We don't have nuttin' */
  23         packet_write(fd[1], "done\n");
  24         if (get_ack(fd[0], sha1))
  25                 error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1));
  26 }
  27
  28 static int is_master(struct ref *ref)
  29 {
  30         return !strcmp(ref->name, "refs/heads/master");
  31 }
  32
  33 static void write_one_ref(struct ref *ref)
  34 {
  35         char *path = git_path("%s", ref->name);
  36         int fd;
  37         char *hex;
  38
  39         if (safe_create_leading_directories(path))
  40                 die("unable to create leading directory for %s", ref->name);
  41         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
  42         if (fd < 0)
  43                 die("unable to create ref %s", ref->name);
  44         hex = sha1_to_hex(ref->old_sha1);
  45         hex[40] = '\n';
  46         if (write(fd, hex, 41) != 41)
  47                 die("unable to write ref %s", ref->name);
  48         close(fd);
  49 }
  50
  51 static void write_refs(struct ref *ref)
  52 {
  53         struct ref *head = NULL, *head_ptr, *master_ref;
  54         char *head_path;
  55
  56         /* Upload-pack must report HEAD first */
  57         if (!strcmp(ref->name, "HEAD")) {
  58                 head = ref;
  59                 ref = ref->next;
  60         }
  61         head_ptr = NULL;
  62         master_ref = NULL;
  63         while (ref) {
  64                 if (is_master(ref))
  65                         master_ref = ref;
  66                 if (head &&
  67                     !memcmp(ref->old_sha1, head->old_sha1, 20) &&
  68                     !strncmp(ref->name, "refs/heads/",11) &&
  69                     (!head_ptr || ref == master_ref))
  70                         head_ptr = ref;
  71
  72                 write_one_ref(ref);
  73                 ref = ref->next;
  74         }
  75         if (!head) {
  76                 fprintf(stderr, "No HEAD in remote.\n");
  77                 return;
  78         }
  79
  80         head_path = strdup(git_path("HEAD"));
  81         if (!head_ptr) {
  82                 /*
  83                  * If we had a master ref, and it wasn't HEAD, we need to undo the
  84                  * symlink, and write a standalone HEAD. Give a warning, because that's
  85                  * really really wrong.
  86                  */
  87                 if (master_ref) {
  88                         error("HEAD doesn't point to any refs! Making standalone HEAD");
  89                         unlink(head_path);
  90                 }
  91                 write_one_ref(head);
  92                 free(head_path);
  93                 return;
  94         }
  95
  96         /* We reset to the master branch if it's available */
  97         if (master_ref)
  98                 return;
  99
 100         fprintf(stderr, "Setting HEAD to %s\n", head_ptr->name);
 101
 102         /*
 103          * Uhhuh. Other end didn't have master. We start HEAD off with
 104          * the first branch with the same value.
 105          */
 106         if (create_symref(head_path, head_ptr->name) < 0)
 107                 die("unable to link HEAD to %s", head_ptr->name);
 108         free(head_path);
 109 }
 110
 111 static int clone_by_unpack(int fd[2])
 112 {
 113         int status;
 114         pid_t pid;
 115
 116         pid = fork();
 117         if (pid < 0)
 118                 die("git-clone-pack: unable to fork off git-unpack-objects");
 119         if (!pid) {
 120                 dup2(fd[0], 0);
 121                 close(fd[0]);
 122                 close(fd[1]);
 123                 execlp("git-unpack-objects", "git-unpack-objects",
 124                         quiet ? "-q" : NULL, NULL);
 125                 die("git-unpack-objects exec failed");
 126         }
 127         close(fd[0]);
 128         close(fd[1]);
 129         while (waitpid(pid, &status, 0) < 0) {
 130                 if (errno != EINTR)
 131                         die("waiting for git-unpack-objects: %s", strerror(errno));
 132         }
 133         if (WIFEXITED(status)) {
 134                 int code = WEXITSTATUS(status);
 135                 if (code)
 136                         die("git-unpack-objects died with error code %d", code);
 137                 return 0;
 138         }
 139         if (WIFSIGNALED(status)) {
 140                 int sig = WTERMSIG(status);
 141                 die("git-unpack-objects died of signal %d", sig);
 142         }
 143         die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 144 }
 145
 146 static int finish_pack(const char *pack_tmp_name)
 147 {
 148         int pipe_fd[2];
 149         pid_t pid;
 150         char idx[PATH_MAX];
 151         char final[PATH_MAX];
 152         char hash[41];
 153         unsigned char sha1[20];
 154         char *cp;
 155         int err = 0;
 156
 157         if (pipe(pipe_fd) < 0)
 158                 die("git-clone-pack: unable to set up pipe");
 159
 160         strcpy(idx, pack_tmp_name); /* ".git/objects/pack-XXXXXX" */
 161         cp = strrchr(idx, '/');
 162         memcpy(cp, "/pidx", 5);
 163
 164         pid = fork();
 165         if (pid < 0)
 166                 die("git-clone-pack: unable to fork off git-index-pack");
 167         if (!pid) {
 168                 close(0);
 169                 dup2(pipe_fd[1], 1);
 170                 close(pipe_fd[0]);
 171                 close(pipe_fd[1]);
 172                 execlp("git-index-pack","git-index-pack",
 173                        "-o", idx, pack_tmp_name, NULL);
 174                 error("cannot exec git-index-pack <%s> <%s>",
 175                       idx, pack_tmp_name);
 176                 exit(1);
 177         }
 178         close(pipe_fd[1]);
 179         if (read(pipe_fd[0], hash, 40) != 40) {
 180                 error("git-clone-pack: unable to read from git-index-pack");
 181                 err = 1;
 182         }
 183         close(pipe_fd[0]);
 184
 185         for (;;) {
 186                 int status, code;
 187                 int retval = waitpid(pid, &status, 0);
 188
 189                 if (retval < 0) {
 190                         if (errno == EINTR)
 191                                 continue;
 192                         error("waitpid failed (%s)", strerror(retval));
 193                         goto error_die;
 194                 }
 195                 if (WIFSIGNALED(status)) {
 196                         int sig = WTERMSIG(status);
 197                         error("git-index-pack died of signal %d", sig);
 198                         goto error_die;
 199                 }
 200                 if (!WIFEXITED(status)) {
 201                         error("git-index-pack died of unnatural causes %d",
 202                               status);
 203                         goto error_die;
 204                 }
 205                 code = WEXITSTATUS(status);
 206                 if (code) {
 207                         error("git-index-pack died with error code %d", code);
 208                         goto error_die;
 209                 }
 210                 if (err)
 211                         goto error_die;
 212                 break;
 213         }
 214         hash[40] = 0;
 215         if (get_sha1_hex(hash, sha1)) {
 216                 error("git-index-pack reported nonsense '%s'", hash);
 217                 goto error_die;
 218         }
 219         /* Now we have pack in pack_tmp_name[], and
 220          * idx in idx[]; rename them to their final names.
 221          */
 222         snprintf(final, sizeof(final),
 223                  "%s/pack/pack-%s.pack", get_object_directory(), hash);
 224         move_temp_to_file(pack_tmp_name, final);
 225         chmod(final, 0444);
 226         snprintf(final, sizeof(final),
 227                  "%s/pack/pack-%s.idx", get_object_directory(), hash);
 228         move_temp_to_file(idx, final);
 229         chmod(final, 0444);
 230         return 0;
 231
 232  error_die:
 233         unlink(idx);
 234         unlink(pack_tmp_name);
 235         exit(1);
 236 }
 237
 238 static int clone_without_unpack(int fd[2])
 239 {
 240         char tmpfile[PATH_MAX];
 241         int ofd, ifd;
 242
 243         ifd = fd[0];
 244         snprintf(tmpfile, sizeof(tmpfile),
 245                  "%s/pack-XXXXXX", get_object_directory());
 246         ofd = mkstemp(tmpfile);
 247         if (ofd < 0)
 248                 return error("unable to create temporary file %s", tmpfile);
 249
 250         while (1) {
 251                 char buf[8192];
 252                 ssize_t sz, wsz, pos;
 253                 sz = read(ifd, buf, sizeof(buf));
 254                 if (sz == 0)
 255                         break;
 256                 if (sz < 0) {
 257                         error("error reading pack (%s)", strerror(errno));
 258                         close(ofd);
 259                         unlink(tmpfile);
 260                         return -1;
 261                 }
 262                 pos = 0;
 263                 while (pos < sz) {
 264                         wsz = write(ofd, buf + pos, sz - pos);
 265                         if (wsz < 0) {
 266                                 error("error writing pack (%s)",
 267                                       strerror(errno));
 268                                 close(ofd);
 269                                 unlink(tmpfile);
 270                                 return -1;
 271                         }
 272                         pos += wsz;
 273                 }
 274         }
 275         close(ofd);
 276         return finish_pack(tmpfile);
 277 }
 278
 279 static int clone_pack(int fd[2], int nr_match, char **match)
 280 {
 281         struct ref *refs;
 282         int status;
 283
 284         get_remote_heads(fd[0], &refs, nr_match, match);
 285         if (!refs) {
 286                 packet_flush(fd[1]);
 287                 die("no matching remote head");
 288         }
 289         clone_handshake(fd, refs);
 290
 291         if (keep_pack)
 292                 status = clone_without_unpack(fd);
 293         else
 294                 status = clone_by_unpack(fd);
 295
 296         if (!status)
 297                 write_refs(refs);
 298         return status;
 299 }
 300
 301 static int clone_options(const char *var, const char *value)
 302 {
 303         if (!strcmp("clone.keeppack", var)) {
 304                 keep_pack = git_config_bool(var, value);
 305                 return 0;
 306         }
 307         if (!strcmp("clone.quiet", var)) {
 308                 quiet = git_config_bool(var, value);
 309                 return 0;
 310         }
 311         /*
 312          * Put other local option parsing for this program
 313          * here ...
 314          */
 315
 316         /* Fall back on the default ones */
 317         return git_default_config(var, value);
 318 }
 319
 320 int main(int argc, char **argv)
 321 {
 322         int i, ret, nr_heads;
 323         char *dest = NULL, **heads;
 324         int fd[2];
 325         pid_t pid;
 326
 327         git_config(clone_options);
 328         nr_heads = 0;
 329         heads = NULL;
 330         for (i = 1; i < argc; i++) {
 331                 char *arg = argv[i];
 332
 333                 if (*arg == '-') {
 334                         if (!strcmp("-q", arg)) {
 335                                 quiet = 1;
 336                                 continue;
 337                         }
 338                         if (!strncmp("--exec=", arg, 7)) {
 339                                 exec = arg + 7;
 340                                 continue;
 341                         }
 342                         if (!strcmp("--keep", arg)) {
 343                                 keep_pack = 1;
 344                                 continue;
 345                         }
 346                         usage(clone_pack_usage);
 347                 }
 348                 dest = arg;
 349                 heads = argv + i + 1;
 350                 nr_heads = argc - i - 1;
 351                 break;
 352         }
 353         if (!dest)
 354                 usage(clone_pack_usage);
 355         pid = git_connect(fd, dest, exec);
 356         if (pid < 0)
 357                 return 1;
 358         ret = clone_pack(fd, nr_heads, heads);
 359         close(fd[0]);
 360         close(fd[1]);
 361         finish_connect(pid);
 362         return ret;
 363 }