builtin-bundle.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "object.h"
   4 #include "commit.h"
   5 #include "diff.h"
   6 #include "revision.h"
   7 #include "list-objects.h"
   8 #include "run-command.h"
   9 #include "refs.h"
  10
  11 /*
  12  * Basic handler for bundle files to connect repositories via sneakernet.
  13  * Invocation must include action.
  14  * This function can create a bundle or provide information on an existing
  15  * bundle supporting git-fetch, git-pull, and git-ls-remote
  16  */
  17
  18 static const char *bundle_usage="git-bundle (create <bundle> <git-rev-list args> | verify <bundle> | list-heads <bundle> [refname]... | unbundle <bundle> [refname]... )";
  19
  20 static const char bundle_signature[] = "# v2 git bundle\n";
  21
  22 struct ref_list {
  23         unsigned int nr, alloc;
  24         struct ref_list_entry {
  25                 unsigned char sha1[20];
  26                 char *name;
  27         } *list;
  28 };
  29
  30 static void add_to_ref_list(const unsigned char *sha1, const char *name,
  31                 struct ref_list *list)
  32 {
  33         if (list->nr + 1 >= list->alloc) {
  34                 list->alloc = alloc_nr(list->nr + 1);
  35                 list->list = xrealloc(list->list,
  36                                 list->alloc * sizeof(list->list[0]));
  37         }
  38         memcpy(list->list[list->nr].sha1, sha1, 20);
  39         list->list[list->nr].name = xstrdup(name);
  40         list->nr++;
  41 }
  42
  43 struct bundle_header {
  44         struct ref_list prerequisites;
  45         struct ref_list references;
  46 };
  47
  48 /* returns an fd */
  49 static int read_header(const char *path, struct bundle_header *header) {
  50         char buffer[1024];
  51         int fd;
  52         long fpos;
  53         FILE *ffd = fopen(path, "rb");
  54
  55         if (!ffd)
  56                 return error("could not open '%s'", path);
  57         if (!fgets(buffer, sizeof(buffer), ffd) ||
  58                         strcmp(buffer, bundle_signature)) {
  59                 fclose(ffd);
  60                 return error("'%s' does not look like a v2 bundle file", path);
  61         }
  62         while (fgets(buffer, sizeof(buffer), ffd)
  63                         && buffer[0] != '\n') {
  64                 int is_prereq = buffer[0] == '-';
  65                 int offset = is_prereq ? 1 : 0;
  66                 int len = strlen(buffer);
  67                 unsigned char sha1[20];
  68                 struct ref_list *list = is_prereq ? &header->prerequisites
  69                         : &header->references;
  70                 char delim;
  71
  72                 if (buffer[len - 1] == '\n')
  73                         buffer[len - 1] = '\0';
  74                 if (get_sha1_hex(buffer + offset, sha1)) {
  75                         warning("unrecognized header: %s", buffer);
  76                         continue;
  77                 }
  78                 delim = buffer[40 + offset];
  79                 if (!isspace(delim) && (delim != '\0' || !is_prereq))
  80                         die ("invalid header: %s", buffer);
  81                 add_to_ref_list(sha1, isspace(delim) ?
  82                                 buffer + 41 + offset : "", list);
  83         }
  84         fpos = ftell(ffd);
  85         fclose(ffd);
  86         fd = open(path, O_RDONLY);
  87         if (fd < 0)
  88                 return error("could not open '%s'", path);
  89         lseek(fd, fpos, SEEK_SET);
  90         return fd;
  91 }
  92
  93 static int list_refs(struct ref_list *r, int argc, const char **argv)
  94 {
  95         int i;
  96
  97         for (i = 0; i < r->nr; i++) {
  98                 if (argc > 1) {
  99                         int j;
 100                         for (j = 1; j < argc; j++)
 101                                 if (!strcmp(r->list[i].name, argv[j]))
 102                                         break;
 103                         if (j == argc)
 104                                 continue;
 105                 }
 106                 printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 107                                 r->list[i].name);
 108         }
 109         return 0;
 110 }
 111
 112 #define PREREQ_MARK (1u<<16)
 113
 114 static int verify_bundle(struct bundle_header *header, int verbose)
 115 {
 116         /*
 117          * Do fast check, then if any prereqs are missing then go line by line
 118          * to be verbose about the errors
 119          */
 120         struct ref_list *p = &header->prerequisites;
 121         struct rev_info revs;
 122         const char *argv[] = {NULL, "--all"};
 123         struct object_array refs;
 124         struct commit *commit;
 125         int i, ret = 0, req_nr;
 126         const char *message = "Repository lacks these prerequisite commits:";
 127
 128         init_revisions(&revs, NULL);
 129         for (i = 0; i < p->nr; i++) {
 130                 struct ref_list_entry *e = p->list + i;
 131                 struct object *o = parse_object(e->sha1);
 132                 if (o) {
 133                         o->flags |= PREREQ_MARK;
 134                         add_pending_object(&revs, o, e->name);
 135                         continue;
 136                 }
 137                 if (++ret == 1)
 138                         error(message);
 139                 error("%s %s", sha1_to_hex(e->sha1), e->name);
 140         }
 141         if (revs.pending.nr != p->nr)
 142                 return ret;
 143         req_nr = revs.pending.nr;
 144         setup_revisions(2, argv, &revs, NULL);
 145
 146         memset(&refs, 0, sizeof(struct object_array));
 147         for (i = 0; i < revs.pending.nr; i++) {
 148                 struct object_array_entry *e = revs.pending.objects + i;
 149                 add_object_array(e->item, e->name, &refs);
 150         }
 151
 152         prepare_revision_walk(&revs);
 153
 154         i = req_nr;
 155         while (i && (commit = get_revision(&revs)))
 156                 if (commit->object.flags & PREREQ_MARK)
 157                         i--;
 158
 159         for (i = 0; i < req_nr; i++)
 160                 if (!(refs.objects[i].item->flags & SHOWN)) {
 161                         if (++ret == 1)
 162                                 error(message);
 163                         error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
 164                                 refs.objects[i].name);
 165                 }
 166
 167         for (i = 0; i < refs.nr; i++)
 168                 clear_commit_marks((struct commit *)refs.objects[i].item, -1);
 169
 170         if (verbose) {
 171                 struct ref_list *r;
 172
 173                 r = &header->references;
 174                 printf("The bundle contains %d ref%s\n",
 175                        r->nr, (1 < r->nr) ? "s" : "");
 176                 list_refs(r, 0, NULL);
 177                 r = &header->prerequisites;
 178                 printf("The bundle requires these %d ref%s\n",
 179                        r->nr, (1 < r->nr) ? "s" : "");
 180                 list_refs(r, 0, NULL);
 181         }
 182         return ret;
 183 }
 184
 185 static int list_heads(struct bundle_header *header, int argc, const char **argv)
 186 {
 187         return list_refs(&header->references, argc, argv);
 188 }
 189
 190 static int create_bundle(struct bundle_header *header, const char *path,
 191                 int argc, const char **argv)
 192 {
 193         static struct lock_file lock;
 194         int bundle_fd = -1;
 195         int bundle_to_stdout;
 196         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 197         const char **argv_pack = xmalloc(5 * sizeof(const char *));
 198         int i, ref_count = 0;
 199         char buffer[1024];
 200         struct rev_info revs;
 201         struct child_process rls;
 202         FILE *rls_fout;
 203
 204         bundle_to_stdout = !strcmp(path, "-");
 205         if (bundle_to_stdout)
 206                 bundle_fd = 1;
 207         else
 208                 bundle_fd = hold_lock_file_for_update(&lock, path, 1);
 209
 210         /* write signature */
 211         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 212
 213         /* init revs to list objects for pack-objects later */
 214         save_commit_buffer = 0;
 215         init_revisions(&revs, NULL);
 216
 217         /* write prerequisites */
 218         memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
 219         argv_boundary[0] = "rev-list";
 220         argv_boundary[1] = "--boundary";
 221         argv_boundary[2] = "--pretty=oneline";
 222         argv_boundary[argc + 2] = NULL;
 223         memset(&rls, 0, sizeof(rls));
 224         rls.argv = argv_boundary;
 225         rls.out = -1;
 226         rls.git_cmd = 1;
 227         if (start_command(&rls))
 228                 return -1;
 229         rls_fout = fdopen(rls.out, "r");
 230         while (fgets(buffer, sizeof(buffer), rls_fout)) {
 231                 unsigned char sha1[20];
 232                 if (buffer[0] == '-') {
 233                         write_or_die(bundle_fd, buffer, strlen(buffer));
 234                         if (!get_sha1_hex(buffer + 1, sha1)) {
 235                                 struct object *object = parse_object(sha1);
 236                                 object->flags |= UNINTERESTING;
 237                                 add_pending_object(&revs, object, buffer);
 238                         }
 239                 } else if (!get_sha1_hex(buffer, sha1)) {
 240                         struct object *object = parse_object(sha1);
 241                         object->flags |= SHOWN;
 242                 }
 243         }
 244         fclose(rls_fout);
 245         if (finish_command(&rls))
 246                 return error("rev-list died");
 247
 248         /* write references */
 249         argc = setup_revisions(argc, argv, &revs, NULL);
 250         if (argc > 1)
 251                 return error("unrecognized argument: %s'", argv[1]);
 252
 253         for (i = 0; i < revs.pending.nr; i++) {
 254                 struct object_array_entry *e = revs.pending.objects + i;
 255                 unsigned char sha1[20];
 256                 char *ref;
 257                 const char *display_ref;
 258                 int flag;
 259
 260                 if (e->item->flags & UNINTERESTING)
 261                         continue;
 262                 if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 263                         continue;
 264                 if (!resolve_ref(e->name, sha1, 1, &flag))
 265                         flag = 0;
 266                 display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
 267
 268                 /*
 269                  * Make sure the refs we wrote out is correct; --max-count and
 270                  * other limiting options could have prevented all the tips
 271                  * from getting output.
 272                  *
 273                  * Non commit objects such as tags and blobs do not have
 274                  * this issue as they are not affected by those extra
 275                  * constraints.
 276                  */
 277                 if (!(e->item->flags & SHOWN) && e->item->type == OBJ_COMMIT) {
 278                         warning("ref '%s' is excluded by the rev-list options",
 279                                 e->name);
 280                         free(ref);
 281                         continue;
 282                 }
 283                 /*
 284                  * If you run "git bundle create bndl v1.0..v2.0", the
 285                  * name of the positive ref is "v2.0" but that is the
 286                  * commit that is referenced by the tag, and not the tag
 287                  * itself.
 288                  */
 289                 if (hashcmp(sha1, e->item->sha1)) {
 290                         /*
 291                          * Is this the positive end of a range expressed
 292                          * in terms of a tag (e.g. v2.0 from the range
 293                          * "v1.0..v2.0")?
 294                          */
 295                         struct commit *one = lookup_commit_reference(sha1);
 296                         struct object *obj;
 297
 298                         if (e->item == &(one->object)) {
 299                                 /*
 300                                  * Need to include e->name as an
 301                                  * independent ref to the pack-objects
 302                                  * input, so that the tag is included
 303                                  * in the output; otherwise we would
 304                                  * end up triggering "empty bundle"
 305                                  * error.
 306                                  */
 307                                 obj = parse_object(sha1);
 308                                 obj->flags |= SHOWN;
 309                                 add_pending_object(&revs, obj, e->name);
 310                         }
 311                         free(ref);
 312                         continue;
 313                 }
 314
 315                 ref_count++;
 316                 write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 317                 write_or_die(bundle_fd, " ", 1);
 318                 write_or_die(bundle_fd, display_ref, strlen(display_ref));
 319                 write_or_die(bundle_fd, "\n", 1);
 320                 free(ref);
 321         }
 322         if (!ref_count)
 323                 die ("Refusing to create empty bundle.");
 324
 325         /* end header */
 326         write_or_die(bundle_fd, "\n", 1);
 327
 328         /* write pack */
 329         argv_pack[0] = "pack-objects";
 330         argv_pack[1] = "--all-progress";
 331         argv_pack[2] = "--stdout";
 332         argv_pack[3] = "--thin";
 333         argv_pack[4] = NULL;
 334         memset(&rls, 0, sizeof(rls));
 335         rls.argv = argv_pack;
 336         rls.in = -1;
 337         rls.out = bundle_fd;
 338         rls.git_cmd = 1;
 339         if (start_command(&rls))
 340                 return error("Could not spawn pack-objects");
 341         for (i = 0; i < revs.pending.nr; i++) {
 342                 struct object *object = revs.pending.objects[i].item;
 343                 if (object->flags & UNINTERESTING)
 344                         write(rls.in, "^", 1);
 345                 write(rls.in, sha1_to_hex(object->sha1), 40);
 346                 write(rls.in, "\n", 1);
 347         }
 348         if (finish_command(&rls))
 349                 return error ("pack-objects died");
 350         close(bundle_fd);
 351         if (!bundle_to_stdout)
 352                 commit_lock_file(&lock);
 353         return 0;
 354 }
 355
 356 static int unbundle(struct bundle_header *header, int bundle_fd,
 357                 int argc, const char **argv)
 358 {
 359         const char *argv_index_pack[] = {"index-pack",
 360                 "--fix-thin", "--stdin", NULL};
 361         struct child_process ip;
 362
 363         if (verify_bundle(header, 0))
 364                 return -1;
 365         memset(&ip, 0, sizeof(ip));
 366         ip.argv = argv_index_pack;
 367         ip.in = bundle_fd;
 368         ip.no_stdout = 1;
 369         ip.git_cmd = 1;
 370         if (run_command(&ip))
 371                 return error("index-pack died");
 372         return list_heads(header, argc, argv);
 373 }
 374
 375 int cmd_bundle(int argc, const char **argv, const char *prefix)
 376 {
 377         struct bundle_header header;
 378         int nongit = 0;
 379         const char *cmd, *bundle_file;
 380         int bundle_fd = -1;
 381         char buffer[PATH_MAX];
 382
 383         if (argc < 3)
 384                 usage(bundle_usage);
 385
 386         cmd = argv[1];
 387         bundle_file = argv[2];
 388         argc -= 2;
 389         argv += 2;
 390
 391         prefix = setup_git_directory_gently(&nongit);
 392         if (prefix && bundle_file[0] != '/') {
 393                 snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 394                 bundle_file = buffer;
 395         }
 396
 397         memset(&header, 0, sizeof(header));
 398         if (strcmp(cmd, "create") &&
 399                         (bundle_fd = read_header(bundle_file, &header)) < 0)
 400                 return 1;
 401
 402         if (!strcmp(cmd, "verify")) {
 403                 close(bundle_fd);
 404                 if (verify_bundle(&header, 1))
 405                         return 1;
 406                 fprintf(stderr, "%s is okay\n", bundle_file);
 407                 return 0;
 408         }
 409         if (!strcmp(cmd, "list-heads")) {
 410                 close(bundle_fd);
 411                 return !!list_heads(&header, argc, argv);
 412         }
 413         if (!strcmp(cmd, "create")) {
 414                 if (nongit)
 415                         die("Need a repository to create a bundle.");
 416                 return !!create_bundle(&header, bundle_file, argc, argv);
 417         } else if (!strcmp(cmd, "unbundle")) {
 418                 if (nongit)
 419                         die("Need a repository to unbundle.");
 420                 return !!unbundle(&header, bundle_fd, argc, argv);
 421         } else
 422                 usage(bundle_usage);
 423 }