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
  10 /*
  11  * Basic handler for bundle files to connect repositories via sneakernet.
  12  * Invocation must include action.
  13  * This function can create a bundle or provide information on an existing
  14  * bundle supporting git-fetch, git-pull, and git-ls-remote
  15  */
  16
  17 static const char *bundle_usage="git-bundle (create <bundle> <git-rev-list args> | verify <bundle> | list-heads <bundle> [refname]... | unbundle <bundle> [refname]... )";
  18
  19 static const char bundle_signature[] = "# v2 git bundle\n";
  20
  21 struct ref_list {
  22         unsigned int nr, alloc;
  23         struct ref_list_entry {
  24                 unsigned char sha1[20];
  25                 char *name;
  26         } *list;
  27 };
  28
  29 static void add_to_ref_list(const unsigned char *sha1, const char *name,
  30                 struct ref_list *list)
  31 {
  32         if (list->nr + 1 >= list->alloc) {
  33                 list->alloc = alloc_nr(list->nr + 1);
  34                 list->list = xrealloc(list->list,
  35                                 list->alloc * sizeof(list->list[0]));
  36         }
  37         memcpy(list->list[list->nr].sha1, sha1, 20);
  38         list->list[list->nr].name = xstrdup(name);
  39         list->nr++;
  40 }
  41
  42 struct bundle_header {
  43         struct ref_list prerequisites;
  44         struct ref_list references;
  45 };
  46
  47 /* returns an fd */
  48 static int read_header(const char *path, struct bundle_header *header) {
  49         char buffer[1024];
  50         int fd;
  51         long fpos;
  52         FILE *ffd = fopen(path, "rb");
  53
  54         if (!ffd)
  55                 return error("could not open '%s'", path);
  56         if (!fgets(buffer, sizeof(buffer), ffd) ||
  57                         strcmp(buffer, bundle_signature)) {
  58                 fclose(ffd);
  59                 return error("'%s' does not look like a v2 bundle file", path);
  60         }
  61         while (fgets(buffer, sizeof(buffer), ffd)
  62                         && buffer[0] != '\n') {
  63                 int is_prereq = buffer[0] == '-';
  64                 int offset = is_prereq ? 1 : 0;
  65                 int len = strlen(buffer);
  66                 unsigned char sha1[20];
  67                 struct ref_list *list = is_prereq ? &header->prerequisites
  68                         : &header->references;
  69                 char delim;
  70
  71                 if (buffer[len - 1] == '\n')
  72                         buffer[len - 1] = '\0';
  73                 if (get_sha1_hex(buffer + offset, sha1)) {
  74                         warning("unrecognized header: %s", buffer);
  75                         continue;
  76                 }
  77                 delim = buffer[40 + offset];
  78                 if (!isspace(delim) && (delim != '\0' || !is_prereq))
  79                         die ("invalid header: %s", buffer);
  80                 add_to_ref_list(sha1, isspace(delim) ?
  81                                 buffer + 41 + offset : "", list);
  82         }
  83         fpos = ftell(ffd);
  84         fclose(ffd);
  85         fd = open(path, O_RDONLY);
  86         if (fd < 0)
  87                 return error("could not open '%s'", path);
  88         lseek(fd, fpos, SEEK_SET);
  89         return fd;
  90 }
  91
  92 static int list_refs(struct ref_list *r, int argc, const char **argv)
  93 {
  94         int i;
  95
  96         for (i = 0; i < r->nr; i++) {
  97                 if (argc > 1) {
  98                         int j;
  99                         for (j = 1; j < argc; j++)
 100                                 if (!strcmp(r->list[i].name, argv[j]))
 101                                         break;
 102                         if (j == argc)
 103                                 continue;
 104                 }
 105                 printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 106                                 r->list[i].name);
 107         }
 108         return 0;
 109 }
 110
 111 #define PREREQ_MARK (1u<<16)
 112
 113 static int verify_bundle(struct bundle_header *header, int verbose)
 114 {
 115         /*
 116          * Do fast check, then if any prereqs are missing then go line by line
 117          * to be verbose about the errors
 118          */
 119         struct ref_list *p = &header->prerequisites;
 120         struct rev_info revs;
 121         const char *argv[] = {NULL, "--all"};
 122         struct object_array refs;
 123         struct commit *commit;
 124         int i, ret = 0, req_nr;
 125         const char *message = "Repository lacks these prerequisite commits:";
 126
 127         init_revisions(&revs, NULL);
 128         for (i = 0; i < p->nr; i++) {
 129                 struct ref_list_entry *e = p->list + i;
 130                 struct object *o = parse_object(e->sha1);
 131                 if (o) {
 132                         o->flags |= PREREQ_MARK;
 133                         add_pending_object(&revs, o, e->name);
 134                         continue;
 135                 }
 136                 if (++ret == 1)
 137                         error(message);
 138                 error("%s %s", sha1_to_hex(e->sha1), e->name);
 139         }
 140         if (revs.pending.nr != p->nr)
 141                 return ret;
 142         req_nr = revs.pending.nr;
 143         setup_revisions(2, argv, &revs, NULL);
 144
 145         memset(&refs, 0, sizeof(struct object_array));
 146         for (i = 0; i < revs.pending.nr; i++) {
 147                 struct object_array_entry *e = revs.pending.objects + i;
 148                 add_object_array(e->item, e->name, &refs);
 149         }
 150
 151         prepare_revision_walk(&revs);
 152
 153         i = req_nr;
 154         while (i && (commit = get_revision(&revs)))
 155                 if (commit->object.flags & PREREQ_MARK)
 156                         i--;
 157
 158         for (i = 0; i < req_nr; i++)
 159                 if (!(refs.objects[i].item->flags & SHOWN)) {
 160                         if (++ret == 1)
 161                                 error(message);
 162                         error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
 163                                 refs.objects[i].name);
 164                 }
 165
 166         for (i = 0; i < refs.nr; i++)
 167                 clear_commit_marks((struct commit *)refs.objects[i].item, -1);
 168
 169         if (verbose) {
 170                 struct ref_list *r;
 171
 172                 r = &header->references;
 173                 printf("The bundle contains %d ref%s\n",
 174                        r->nr, (1 < r->nr) ? "s" : "");
 175                 list_refs(r, 0, NULL);
 176                 r = &header->prerequisites;
 177                 printf("The bundle requires these %d ref%s\n",
 178                        r->nr, (1 < r->nr) ? "s" : "");
 179                 list_refs(r, 0, NULL);
 180         }
 181         return ret;
 182 }
 183
 184 static int list_heads(struct bundle_header *header, int argc, const char **argv)
 185 {
 186         return list_refs(&header->references, argc, argv);
 187 }
 188
 189 static int create_bundle(struct bundle_header *header, const char *path,
 190                 int argc, const char **argv)
 191 {
 192         int bundle_fd = -1;
 193         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 194         const char **argv_pack = xmalloc(5 * sizeof(const char *));
 195         int i, ref_count = 0;
 196         char buffer[1024];
 197         struct rev_info revs;
 198         struct child_process rls;
 199         FILE *rls_fout;
 200
 201         /*
 202          * NEEDSWORK: this should use something like lock-file
 203          * to create temporary that is cleaned up upon error.
 204          */
 205         bundle_fd = (!strcmp(path, "-") ? 1 :
 206                         open(path, O_CREAT | O_EXCL | O_WRONLY, 0666));
 207         if (bundle_fd < 0)
 208                 return error("Could not create '%s': %s", path, strerror(errno));
 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
 258                 if (e->item->flags & UNINTERESTING)
 259                         continue;
 260                 if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 261                         continue;
 262                 /*
 263                  * Make sure the refs we wrote out is correct; --max-count and
 264                  * other limiting options could have prevented all the tips
 265                  * from getting output.
 266                  *
 267                  * Non commit objects such as tags and blobs do not have
 268                  * this issue as they are not affected by those extra
 269                  * constraints.
 270                  */
 271                 if (!(e->item->flags & SHOWN) && e->item->type == OBJ_COMMIT) {
 272                         warning("ref '%s' is excluded by the rev-list options",
 273                                 e->name);
 274                         free(ref);
 275                         continue;
 276                 }
 277                 /*
 278                  * If you run "git bundle create bndl v1.0..v2.0", the
 279                  * name of the positive ref is "v2.0" but that is the
 280                  * commit that is referenced by the tag, and not the tag
 281                  * itself.
 282                  */
 283                 if (hashcmp(sha1, e->item->sha1)) {
 284                         /*
 285                          * Is this the positive end of a range expressed
 286                          * in terms of a tag (e.g. v2.0 from the range
 287                          * "v1.0..v2.0")?
 288                          */
 289                         struct commit *one = lookup_commit_reference(sha1);
 290                         struct object *obj;
 291
 292                         if (e->item == &(one->object)) {
 293                                 /*
 294                                  * Need to include e->name as an
 295                                  * independent ref to the pack-objects
 296                                  * input, so that the tag is included
 297                                  * in the output; otherwise we would
 298                                  * end up triggering "empty bundle"
 299                                  * error.
 300                                  */
 301                                 obj = parse_object(sha1);
 302                                 obj->flags |= SHOWN;
 303                                 add_pending_object(&revs, obj, e->name);
 304                         }
 305                         free(ref);
 306                         continue;
 307                 }
 308
 309                 ref_count++;
 310                 write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 311                 write_or_die(bundle_fd, " ", 1);
 312                 write_or_die(bundle_fd, ref, strlen(ref));
 313                 write_or_die(bundle_fd, "\n", 1);
 314                 free(ref);
 315         }
 316         if (!ref_count)
 317                 die ("Refusing to create empty bundle.");
 318
 319         /* end header */
 320         write_or_die(bundle_fd, "\n", 1);
 321
 322         /* write pack */
 323         argv_pack[0] = "pack-objects";
 324         argv_pack[1] = "--all-progress";
 325         argv_pack[2] = "--stdout";
 326         argv_pack[3] = "--thin";
 327         argv_pack[4] = NULL;
 328         memset(&rls, 0, sizeof(rls));
 329         rls.argv = argv_pack;
 330         rls.in = -1;
 331         rls.out = bundle_fd;
 332         rls.git_cmd = 1;
 333         if (start_command(&rls))
 334                 return error("Could not spawn pack-objects");
 335         for (i = 0; i < revs.pending.nr; i++) {
 336                 struct object *object = revs.pending.objects[i].item;
 337                 if (object->flags & UNINTERESTING)
 338                         write(rls.in, "^", 1);
 339                 write(rls.in, sha1_to_hex(object->sha1), 40);
 340                 write(rls.in, "\n", 1);
 341         }
 342         if (finish_command(&rls))
 343                 return error ("pack-objects died");
 344         return 0;
 345 }
 346
 347 static int unbundle(struct bundle_header *header, int bundle_fd,
 348                 int argc, const char **argv)
 349 {
 350         const char *argv_index_pack[] = {"index-pack",
 351                 "--fix-thin", "--stdin", NULL};
 352         struct child_process ip;
 353
 354         if (verify_bundle(header, 0))
 355                 return -1;
 356         memset(&ip, 0, sizeof(ip));
 357         ip.argv = argv_index_pack;
 358         ip.in = bundle_fd;
 359         ip.no_stdout = 1;
 360         ip.git_cmd = 1;
 361         if (run_command(&ip))
 362                 return error("index-pack died");
 363         return list_heads(header, argc, argv);
 364 }
 365
 366 int cmd_bundle(int argc, const char **argv, const char *prefix)
 367 {
 368         struct bundle_header header;
 369         int nongit = 0;
 370         const char *cmd, *bundle_file;
 371         int bundle_fd = -1;
 372         char buffer[PATH_MAX];
 373
 374         if (argc < 3)
 375                 usage(bundle_usage);
 376
 377         cmd = argv[1];
 378         bundle_file = argv[2];
 379         argc -= 2;
 380         argv += 2;
 381
 382         prefix = setup_git_directory_gently(&nongit);
 383         if (prefix && bundle_file[0] != '/') {
 384                 snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 385                 bundle_file = buffer;
 386         }
 387
 388         memset(&header, 0, sizeof(header));
 389         if (strcmp(cmd, "create") &&
 390                         (bundle_fd = read_header(bundle_file, &header)) < 0)
 391                 return 1;
 392
 393         if (!strcmp(cmd, "verify")) {
 394                 close(bundle_fd);
 395                 if (verify_bundle(&header, 1))
 396                         return 1;
 397                 fprintf(stderr, "%s is okay\n", bundle_file);
 398                 return 0;
 399         }
 400         if (!strcmp(cmd, "list-heads")) {
 401                 close(bundle_fd);
 402                 return !!list_heads(&header, argc, argv);
 403         }
 404         if (!strcmp(cmd, "create")) {
 405                 if (nongit)
 406                         die("Need a repository to create a bundle.");
 407                 return !!create_bundle(&header, bundle_file, argc, argv);
 408         } else if (!strcmp(cmd, "unbundle")) {
 409                 if (nongit)
 410                         die("Need a repository to unbundle.");
 411                 return !!unbundle(&header, bundle_fd, argc, argv);
 412         } else
 413                 usage(bundle_usage);
 414 }