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