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 void show_commit(struct commit *commit)
 261 {
 262         write_or_die(1, sha1_to_hex(commit->object.sha1), 40);
 263         write_or_die(1, "\n", 1);
 264         if (commit->parents) {
 265                 free_commit_list(commit->parents);
 266                 commit->parents = NULL;
 267         }
 268 }
 269
 270 static void show_object(struct object_array_entry *p)
 271 {
 272         /* An object with name "foo\n0000000..." can be used to
 273          * confuse downstream git-pack-objects very badly.
 274          */
 275         const char *ep = strchr(p->name, '\n');
 276         int len = ep ? ep - p->name : strlen(p->name);
 277         write_or_die(1, sha1_to_hex(p->item->sha1), 40);
 278         write_or_die(1, " ", 1);
 279         if (len)
 280                 write_or_die(1, p->name, len);
 281         write_or_die(1, "\n", 1);
 282 }
 283
 284 static void show_edge(struct commit *commit)
 285 {
 286         ; /* nothing to do */
 287 }
 288
 289 static int create_bundle(struct bundle_header *header, const char *path,
 290                 int argc, const char **argv)
 291 {
 292         int bundle_fd = -1;
 293         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 294         const char **argv_pack = xmalloc(4 * sizeof(const char *));
 295         int pid, in, out, i, status;
 296         char buffer[1024];
 297         struct rev_info revs;
 298         struct object_array tips;
 299
 300         bundle_fd = (!strcmp(path, "-") ? 1 :
 301                         open(path, O_CREAT | O_WRONLY, 0666));
 302         if (bundle_fd < 0)
 303                 return error("Could not write to '%s'", path);
 304
 305         /* write signature */
 306         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 307
 308         /* init revs to list objects for pack-objects later */
 309         save_commit_buffer = 0;
 310         init_revisions(&revs, NULL);
 311
 312         /* write prerequisites */
 313         memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
 314         argv_boundary[0] = "rev-list";
 315         argv_boundary[1] = "--boundary";
 316         argv_boundary[2] = "--pretty=oneline";
 317         argv_boundary[argc + 2] = NULL;
 318         out = -1;
 319         pid = fork_with_pipe(argv_boundary, NULL, &out);
 320         if (pid < 0)
 321                 return -1;
 322         while ((i = read_string(out, buffer, sizeof(buffer))) > 0)
 323                 if (buffer[0] == '-') {
 324                         unsigned char sha1[20];
 325                         write_or_die(bundle_fd, buffer, i);
 326                         if (!get_sha1_hex(buffer + 1, sha1)) {
 327                                 struct object *object = parse_object(sha1);
 328                                 object->flags |= UNINTERESTING;
 329                                 add_pending_object(&revs, object, buffer);
 330                         }
 331                 }
 332         while ((i = waitpid(pid, &status, 0)) < 0)
 333                 if (errno != EINTR)
 334                         return error("rev-list died");
 335         if (!WIFEXITED(status) || WEXITSTATUS(status))
 336                 return error("rev-list died %d", WEXITSTATUS(status));
 337
 338         /* write references */
 339         revs.tag_objects = 1;
 340         revs.tree_objects = 1;
 341         revs.blob_objects = 1;
 342         argc = setup_revisions(argc, argv, &revs, NULL);
 343         if (argc > 1)
 344                 return error("unrecognized argument: %s'", argv[1]);
 345
 346         memset(&tips, 0, sizeof(tips));
 347         for (i = 0; i < revs.pending.nr; i++) {
 348                 struct object_array_entry *e = revs.pending.objects + i;
 349                 unsigned char sha1[20];
 350                 char *ref;
 351
 352                 if (e->item->flags & UNINTERESTING)
 353                         continue;
 354                 if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 355                         continue;
 356                 write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 357                 write_or_die(bundle_fd, " ", 1);
 358                 write_or_die(bundle_fd, ref, strlen(ref));
 359                 write_or_die(bundle_fd, "\n", 1);
 360                 add_object_array(e->item, e->name, &tips);
 361                 free(ref);
 362         }
 363
 364         /* end header */
 365         write_or_die(bundle_fd, "\n", 1);
 366
 367         /* write pack */
 368         argv_pack[0] = "pack-objects";
 369         argv_pack[1] = "--all-progress";
 370         argv_pack[2] = "--stdout";
 371         argv_pack[3] = NULL;
 372         in = -1;
 373         out = bundle_fd;
 374         pid = fork_with_pipe(argv_pack, &in, &out);
 375         if (pid < 0)
 376                 return error("Could not spawn pack-objects");
 377         close(1);
 378         dup2(in, 1);
 379         close(in);
 380         prepare_revision_walk(&revs);
 381         mark_edges_uninteresting(revs.commits, &revs, show_edge);
 382         traverse_commit_list(&revs, show_commit, show_object);
 383         close(1);
 384         while (waitpid(pid, &status, 0) < 0)
 385                 if (errno != EINTR)
 386                         return -1;
 387         if (!WIFEXITED(status) || WEXITSTATUS(status))
 388                 return error ("pack-objects died");
 389
 390         /*
 391          * Make sure the refs we wrote out is correct; --max-count and
 392          * other limiting options could have prevented all the tips
 393          * from getting output.
 394          */
 395         status = 0;
 396         for (i = 0; i < tips.nr; i++) {
 397                 if (!(tips.objects[i].item->flags & SHOWN)) {
 398                         status = 1;
 399                         error("%s: not included in the resulting pack",
 400                               tips.objects[i].name);
 401                 }
 402         }
 403
 404         return status;
 405 }
 406
 407 static int unbundle(struct bundle_header *header, int bundle_fd,
 408                 int argc, const char **argv)
 409 {
 410         const char *argv_index_pack[] = {"index-pack", "--stdin", NULL};
 411         int pid, status, dev_null;
 412
 413         if (verify_bundle(header, 0))
 414                 return -1;
 415         dev_null = open("/dev/null", O_WRONLY);
 416         if (dev_null < 0)
 417                 return error("Could not open /dev/null");
 418         pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null);
 419         if (pid < 0)
 420                 return error("Could not spawn index-pack");
 421         while (waitpid(pid, &status, 0) < 0)
 422                 if (errno != EINTR)
 423                         return error("index-pack died");
 424         if (!WIFEXITED(status) || WEXITSTATUS(status))
 425                 return error("index-pack exited with status %d",
 426                                 WEXITSTATUS(status));
 427         return list_heads(header, argc, argv);
 428 }
 429
 430 int cmd_bundle(int argc, const char **argv, const char *prefix)
 431 {
 432         struct bundle_header header;
 433         int nongit = 0;
 434         const char *cmd, *bundle_file;
 435         int bundle_fd = -1;
 436         char buffer[PATH_MAX];
 437
 438         if (argc < 3)
 439                 usage(bundle_usage);
 440
 441         cmd = argv[1];
 442         bundle_file = argv[2];
 443         argc -= 2;
 444         argv += 2;
 445
 446         prefix = setup_git_directory_gently(&nongit);
 447         if (prefix && bundle_file[0] != '/') {
 448                 snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 449                 bundle_file = buffer;
 450         }
 451
 452         memset(&header, 0, sizeof(header));
 453         if (strcmp(cmd, "create") &&
 454                         (bundle_fd = read_header(bundle_file, &header)) < 0)
 455                 return 1;
 456
 457         if (!strcmp(cmd, "verify")) {
 458                 close(bundle_fd);
 459                 if (verify_bundle(&header, 1))
 460                         return 1;
 461                 fprintf(stderr, "%s is okay\n", bundle_file);
 462                 return 0;
 463         }
 464         if (!strcmp(cmd, "list-heads")) {
 465                 close(bundle_fd);
 466                 return !!list_heads(&header, argc, argv);
 467         }
 468         if (!strcmp(cmd, "create")) {
 469                 if (nongit)
 470                         die("Need a repository to create a bundle.");
 471                 return !!create_bundle(&header, bundle_file, argc, argv);
 472         } else if (!strcmp(cmd, "unbundle")) {
 473                 if (nongit)
 474                         die("Need a repository to unbundle.");
 475                 return !!unbundle(&header, bundle_fd, argc, argv);
 476         } else
 477                 usage(bundle_usage);
 478 }