builtin-bundle.c

   1 #include "cache.h"
   2 #include "object.h"
   3 #include "commit.h"
   4 #include "diff.h"
   5 #include "revision.h"
   6 #include "list-objects.h"
   7 #include "exec_cmd.h"
   8
   9 /*
  10  * Basic handler for bundle files to connect repositories via sneakernet.
  11  * Invocation must include action.
  12  * This function can create a bundle or provide information on an existing
  13  * bundle supporting git-fetch, git-pull, and git-ls-remote
  14  */
  15
  16 static const char *bundle_usage="git-bundle (create <bundle> <git-rev-list args> | verify <bundle> | list-heads <bundle> [refname]... | unbundle <bundle> [refname]... )";
  17
  18 static const char bundle_signature[] = "# v2 git bundle\n";
  19
  20 struct ref_list {
  21         unsigned int nr, alloc;
  22         struct ref_list_entry {
  23                 unsigned char sha1[20];
  24                 char *name;
  25         } *list;
  26 };
  27
  28 static void add_to_ref_list(const unsigned char *sha1, const char *name,
  29                 struct ref_list *list)
  30 {
  31         if (list->nr + 1 >= list->alloc) {
  32                 list->alloc = alloc_nr(list->nr + 1);
  33                 list->list = xrealloc(list->list,
  34                                 list->alloc * sizeof(list->list[0]));
  35         }
  36         memcpy(list->list[list->nr].sha1, sha1, 20);
  37         list->list[list->nr].name = xstrdup(name);
  38         list->nr++;
  39 }
  40
  41 struct bundle_header {
  42         struct ref_list prerequisites;
  43         struct ref_list references;
  44 };
  45
  46 /* this function returns the length of the string */
  47 static int read_string(int fd, char *buffer, int size)
  48 {
  49         int i;
  50         for (i = 0; i < size - 1; i++) {
  51                 int count = xread(fd, buffer + i, 1);
  52                 if (count < 0)
  53                         return error("Read error: %s", strerror(errno));
  54                 if (count == 0) {
  55                         i--;
  56                         break;
  57                 }
  58                 if (buffer[i] == '\n')
  59                         break;
  60         }
  61         buffer[i + 1] = '\0';
  62         return i + 1;
  63 }
  64
  65 /* returns an fd */
  66 static int read_header(const char *path, struct bundle_header *header) {
  67         char buffer[1024];
  68         int fd = open(path, O_RDONLY);
  69
  70         if (fd < 0)
  71                 return error("could not open '%s'", path);
  72         if (read_string(fd, buffer, sizeof(buffer)) < 0 ||
  73                         strcmp(buffer, bundle_signature)) {
  74                 close(fd);
  75                 return error("'%s' does not look like a v2 bundle file", path);
  76         }
  77         while (read_string(fd, buffer, sizeof(buffer)) > 0
  78                         && buffer[0] != '\n') {
  79                 int is_prereq = buffer[0] == '-';
  80                 int offset = is_prereq ? 1 : 0;
  81                 int len = strlen(buffer);
  82                 unsigned char sha1[20];
  83                 struct ref_list *list = is_prereq ? &header->prerequisites
  84                         : &header->references;
  85                 char delim;
  86
  87                 if (buffer[len - 1] == '\n')
  88                         buffer[len - 1] = '\0';
  89                 if (get_sha1_hex(buffer + offset, sha1)) {
  90                         warn("unrecognized header: %s", buffer);
  91                         continue;
  92                 }
  93                 delim = buffer[40 + offset];
  94                 if (!isspace(delim) && (delim != '\0' || !is_prereq))
  95                         die ("invalid header: %s", buffer);
  96                 add_to_ref_list(sha1, isspace(delim) ?
  97                                 buffer + 41 + offset : "", list);
  98         }
  99         return fd;
 100 }
 101
 102 /* if in && *in >= 0, take that as input file descriptor instead */
 103 static int fork_with_pipe(const char **argv, int *in, int *out)
 104 {
 105         int needs_in, needs_out;
 106         int fdin[2], fdout[2], pid;
 107
 108         needs_in = in && *in < 0;
 109         if (needs_in) {
 110                 if (pipe(fdin) < 0)
 111                         return error("could not setup pipe");
 112                 *in = fdin[1];
 113         }
 114
 115         needs_out = out && *out < 0;
 116         if (needs_out) {
 117                 if (pipe(fdout) < 0)
 118                         return error("could not setup pipe");
 119                 *out = fdout[0];
 120         }
 121
 122         if ((pid = fork()) < 0) {
 123                 if (needs_in) {
 124                         close(fdin[0]);
 125                         close(fdin[1]);
 126                 }
 127                 if (needs_out) {
 128                         close(fdout[0]);
 129                         close(fdout[1]);
 130                 }
 131                 return error("could not fork");
 132         }
 133         if (!pid) {
 134                 if (needs_in) {
 135                         dup2(fdin[0], 0);
 136                         close(fdin[0]);
 137                         close(fdin[1]);
 138                 } else if (in) {
 139                         dup2(*in, 0);
 140                         close(*in);
 141                 }
 142                 if (needs_out) {
 143                         dup2(fdout[1], 1);
 144                         close(fdout[0]);
 145                         close(fdout[1]);
 146                 } else if (out) {
 147                         dup2(*out, 1);
 148                         close(*out);
 149                 }
 150                 exit(execv_git_cmd(argv));
 151         }
 152         if (needs_in)
 153                 close(fdin[0]);
 154         else if (in)
 155                 close(*in);
 156         if (needs_out)
 157                 close(fdout[1]);
 158         else if (out)
 159                 close(*out);
 160         return pid;
 161 }
 162
 163 static int list_refs(struct ref_list *r, int argc, const char **argv)
 164 {
 165         int i;
 166
 167         for (i = 0; i < r->nr; i++) {
 168                 if (argc > 1) {
 169                         int j;
 170                         for (j = 1; j < argc; j++)
 171                                 if (!strcmp(r->list[i].name, argv[j]))
 172                                         break;
 173                         if (j == argc)
 174                                 continue;
 175                 }
 176                 printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 177                                 r->list[i].name);
 178         }
 179         return 0;
 180 }
 181
 182 #define PREREQ_MARK (1u<<16)
 183
 184 static int verify_bundle(struct bundle_header *header, int verbose)
 185 {
 186         /*
 187          * Do fast check, then if any prereqs are missing then go line by line
 188          * to be verbose about the errors
 189          */
 190         struct ref_list *p = &header->prerequisites;
 191         struct rev_info revs;
 192         const char *argv[] = {NULL, "--all"};
 193         struct object_array refs;
 194         struct commit *commit;
 195         int i, ret = 0, req_nr;
 196         const char *message = "Repository lacks these prerequisite commits:";
 197
 198         init_revisions(&revs, NULL);
 199         for (i = 0; i < p->nr; i++) {
 200                 struct ref_list_entry *e = p->list + i;
 201                 struct object *o = parse_object(e->sha1);
 202                 if (o) {
 203                         o->flags |= PREREQ_MARK;
 204                         add_pending_object(&revs, o, e->name);
 205                         continue;
 206                 }
 207                 if (++ret == 1)
 208                         error(message);
 209                 error("%s %s", sha1_to_hex(e->sha1), e->name);
 210         }
 211         if (revs.pending.nr != p->nr)
 212                 return ret;
 213         req_nr = revs.pending.nr;
 214         setup_revisions(2, argv, &revs, NULL);
 215
 216         memset(&refs, 0, sizeof(struct object_array));
 217         for (i = 0; i < revs.pending.nr; i++) {
 218                 struct object_array_entry *e = revs.pending.objects + i;
 219                 add_object_array(e->item, e->name, &refs);
 220         }
 221
 222         prepare_revision_walk(&revs);
 223
 224         i = req_nr;
 225         while (i && (commit = get_revision(&revs)))
 226                 if (commit->object.flags & PREREQ_MARK)
 227                         i--;
 228
 229         for (i = 0; i < req_nr; i++)
 230                 if (!(refs.objects[i].item->flags & SHOWN)) {
 231                         if (++ret == 1)
 232                                 error(message);
 233                         error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
 234                                 refs.objects[i].name);
 235                 }
 236
 237         for (i = 0; i < refs.nr; i++)
 238                 clear_commit_marks((struct commit *)refs.objects[i].item, -1);
 239
 240         if (verbose) {
 241                 struct ref_list *r;
 242
 243                 r = &header->references;
 244                 printf("The bundle contains %d ref%s\n",
 245                        r->nr, (1 < r->nr) ? "s" : "");
 246                 list_refs(r, 0, NULL);
 247                 r = &header->prerequisites;
 248                 printf("The bundle requires these %d ref%s\n",
 249                        r->nr, (1 < r->nr) ? "s" : "");
 250                 list_refs(r, 0, NULL);
 251         }
 252         return ret;
 253 }
 254
 255 static int list_heads(struct bundle_header *header, int argc, const char **argv)
 256 {
 257         return list_refs(&header->references, argc, argv);
 258 }
 259
 260 static int create_bundle(struct bundle_header *header, const char *path,
 261                 int argc, const char **argv)
 262 {
 263         int bundle_fd = -1;
 264         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 265         const char **argv_pack = xmalloc(5 * sizeof(const char *));
 266         int pid, in, out, i, status, ref_count = 0;
 267         char buffer[1024];
 268         struct rev_info revs;
 269
 270         bundle_fd = (!strcmp(path, "-") ? 1 :
 271                         open(path, O_CREAT | O_EXCL | O_WRONLY, 0666));
 272         if (bundle_fd < 0)
 273                 return error("Could not create '%s': %s", path, strerror(errno));
 274
 275         /* write signature */
 276         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 277
 278         /* init revs to list objects for pack-objects later */
 279         save_commit_buffer = 0;
 280         init_revisions(&revs, NULL);
 281
 282         /* write prerequisites */
 283         memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
 284         argv_boundary[0] = "rev-list";
 285         argv_boundary[1] = "--boundary";
 286         argv_boundary[2] = "--pretty=oneline";
 287         argv_boundary[argc + 2] = NULL;
 288         out = -1;
 289         pid = fork_with_pipe(argv_boundary, NULL, &out);
 290         if (pid < 0)
 291                 return -1;
 292         while ((i = read_string(out, buffer, sizeof(buffer))) > 0) {
 293                 unsigned char sha1[20];
 294                 if (buffer[0] == '-') {
 295                         write_or_die(bundle_fd, buffer, i);
 296                         if (!get_sha1_hex(buffer + 1, sha1)) {
 297                                 struct object *object = parse_object(sha1);
 298                                 object->flags |= UNINTERESTING;
 299                                 add_pending_object(&revs, object, buffer);
 300                         }
 301                 } else if (!get_sha1_hex(buffer, sha1)) {
 302                         struct object *object = parse_object(sha1);
 303                         object->flags |= SHOWN;
 304                 }
 305         }
 306         while ((i = waitpid(pid, &status, 0)) < 0)
 307                 if (errno != EINTR)
 308                         return error("rev-list died");
 309         if (!WIFEXITED(status) || WEXITSTATUS(status))
 310                 return error("rev-list died %d", WEXITSTATUS(status));
 311
 312         /* write references */
 313         argc = setup_revisions(argc, argv, &revs, NULL);
 314         if (argc > 1)
 315                 return error("unrecognized argument: %s'", argv[1]);
 316
 317         for (i = 0; i < revs.pending.nr; i++) {
 318                 struct object_array_entry *e = revs.pending.objects + i;
 319                 unsigned char sha1[20];
 320                 char *ref;
 321
 322                 if (e->item->flags & UNINTERESTING)
 323                         continue;
 324                 if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 325                         continue;
 326                 /*
 327                  * Make sure the refs we wrote out is correct; --max-count and
 328                  * other limiting options could have prevented all the tips
 329                  * from getting output.
 330                  */
 331                 if (!(e->item->flags & SHOWN)) {
 332                         warn("ref '%s' is excluded by the rev-list options",
 333                                 e->name);
 334                         continue;
 335                 }
 336                 ref_count++;
 337                 write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 338                 write_or_die(bundle_fd, " ", 1);
 339                 write_or_die(bundle_fd, ref, strlen(ref));
 340                 write_or_die(bundle_fd, "\n", 1);
 341                 free(ref);
 342         }
 343         if (!ref_count)
 344                 die ("Refusing to create empty bundle.");
 345
 346         /* end header */
 347         write_or_die(bundle_fd, "\n", 1);
 348
 349         /* write pack */
 350         argv_pack[0] = "pack-objects";
 351         argv_pack[1] = "--all-progress";
 352         argv_pack[2] = "--stdout";
 353         argv_pack[3] = "--thin";
 354         argv_pack[4] = NULL;
 355         in = -1;
 356         out = bundle_fd;
 357         pid = fork_with_pipe(argv_pack, &in, &out);
 358         if (pid < 0)
 359                 return error("Could not spawn pack-objects");
 360         for (i = 0; i < revs.pending.nr; i++) {
 361                 struct object *object = revs.pending.objects[i].item;
 362                 if (object->flags & UNINTERESTING)
 363                         write(in, "^", 1);
 364                 write(in, sha1_to_hex(object->sha1), 40);
 365                 write(in, "\n", 1);
 366         }
 367         close(in);
 368         while (waitpid(pid, &status, 0) < 0)
 369                 if (errno != EINTR)
 370                         return -1;
 371         if (!WIFEXITED(status) || WEXITSTATUS(status))
 372                 return error ("pack-objects died");
 373
 374         return status;
 375 }
 376
 377 static int unbundle(struct bundle_header *header, int bundle_fd,
 378                 int argc, const char **argv)
 379 {
 380         const char *argv_index_pack[] = {"index-pack",
 381                 "--fix-thin", "--stdin", NULL};
 382         int pid, status, dev_null;
 383
 384         if (verify_bundle(header, 0))
 385                 return -1;
 386         dev_null = open("/dev/null", O_WRONLY);
 387         if (dev_null < 0)
 388                 return error("Could not open /dev/null");
 389         pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null);
 390         if (pid < 0)
 391                 return error("Could not spawn index-pack");
 392         while (waitpid(pid, &status, 0) < 0)
 393                 if (errno != EINTR)
 394                         return error("index-pack died");
 395         if (!WIFEXITED(status) || WEXITSTATUS(status))
 396                 return error("index-pack exited with status %d",
 397                                 WEXITSTATUS(status));
 398         return list_heads(header, argc, argv);
 399 }
 400
 401 int cmd_bundle(int argc, const char **argv, const char *prefix)
 402 {
 403         struct bundle_header header;
 404         int nongit = 0;
 405         const char *cmd, *bundle_file;
 406         int bundle_fd = -1;
 407         char buffer[PATH_MAX];
 408
 409         if (argc < 3)
 410                 usage(bundle_usage);
 411
 412         cmd = argv[1];
 413         bundle_file = argv[2];
 414         argc -= 2;
 415         argv += 2;
 416
 417         prefix = setup_git_directory_gently(&nongit);
 418         if (prefix && bundle_file[0] != '/') {
 419                 snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 420                 bundle_file = buffer;
 421         }
 422
 423         memset(&header, 0, sizeof(header));
 424         if (strcmp(cmd, "create") &&
 425                         (bundle_fd = read_header(bundle_file, &header)) < 0)
 426                 return 1;
 427
 428         if (!strcmp(cmd, "verify")) {
 429                 close(bundle_fd);
 430                 if (verify_bundle(&header, 1))
 431                         return 1;
 432                 fprintf(stderr, "%s is okay\n", bundle_file);
 433                 return 0;
 434         }
 435         if (!strcmp(cmd, "list-heads")) {
 436                 close(bundle_fd);
 437                 return !!list_heads(&header, argc, argv);
 438         }
 439         if (!strcmp(cmd, "create")) {
 440                 if (nongit)
 441                         die("Need a repository to create a bundle.");
 442                 return !!create_bundle(&header, bundle_file, argc, argv);
 443         } else if (!strcmp(cmd, "unbundle")) {
 444                 if (nongit)
 445                         die("Need a repository to unbundle.");
 446                 return !!unbundle(&header, bundle_fd, argc, argv);
 447         } else
 448                 usage(bundle_usage);
 449 }