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 /* this function returns the length of the string */
  48 static int read_string(int fd, char *buffer, int size)
  49 {
  50         int i;
  51         for (i = 0; i < size - 1; i++) {
  52                 ssize_t count = xread(fd, buffer + i, 1);
  53                 if (count < 0)
  54                         return error("Read error: %s", strerror(errno));
  55                 if (count == 0) {
  56                         i--;
  57                         break;
  58                 }
  59                 if (buffer[i] == '\n')
  60                         break;
  61         }
  62         buffer[i + 1] = '\0';
  63         return i + 1;
  64 }
  65
  66 /* returns an fd */
  67 static int read_header(const char *path, struct bundle_header *header) {
  68         char buffer[1024];
  69         int fd = open(path, O_RDONLY);
  70
  71         if (fd < 0)
  72                 return error("could not open '%s'", path);
  73         if (read_string(fd, buffer, sizeof(buffer)) < 0 ||
  74                         strcmp(buffer, bundle_signature)) {
  75                 close(fd);
  76                 return error("'%s' does not look like a v2 bundle file", path);
  77         }
  78         while (read_string(fd, buffer, sizeof(buffer)) > 0
  79                         && buffer[0] != '\n') {
  80                 int is_prereq = buffer[0] == '-';
  81                 int offset = is_prereq ? 1 : 0;
  82                 int len = strlen(buffer);
  83                 unsigned char sha1[20];
  84                 struct ref_list *list = is_prereq ? &header->prerequisites
  85                         : &header->references;
  86                 char delim;
  87
  88                 if (buffer[len - 1] == '\n')
  89                         buffer[len - 1] = '\0';
  90                 if (get_sha1_hex(buffer + offset, sha1)) {
  91                         warning("unrecognized header: %s", buffer);
  92                         continue;
  93                 }
  94                 delim = buffer[40 + offset];
  95                 if (!isspace(delim) && (delim != '\0' || !is_prereq))
  96                         die ("invalid header: %s", buffer);
  97                 add_to_ref_list(sha1, isspace(delim) ?
  98                                 buffer + 41 + offset : "", list);
  99         }
 100         return fd;
 101 }
 102
 103 static int list_refs(struct ref_list *r, int argc, const char **argv)
 104 {
 105         int i;
 106
 107         for (i = 0; i < r->nr; i++) {
 108                 if (argc > 1) {
 109                         int j;
 110                         for (j = 1; j < argc; j++)
 111                                 if (!strcmp(r->list[i].name, argv[j]))
 112                                         break;
 113                         if (j == argc)
 114                                 continue;
 115                 }
 116                 printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 117                                 r->list[i].name);
 118         }
 119         return 0;
 120 }
 121
 122 #define PREREQ_MARK (1u<<16)
 123
 124 static int verify_bundle(struct bundle_header *header, int verbose)
 125 {
 126         /*
 127          * Do fast check, then if any prereqs are missing then go line by line
 128          * to be verbose about the errors
 129          */
 130         struct ref_list *p = &header->prerequisites;
 131         struct rev_info revs;
 132         const char *argv[] = {NULL, "--all"};
 133         struct object_array refs;
 134         struct commit *commit;
 135         int i, ret = 0, req_nr;
 136         const char *message = "Repository lacks these prerequisite commits:";
 137
 138         init_revisions(&revs, NULL);
 139         for (i = 0; i < p->nr; i++) {
 140                 struct ref_list_entry *e = p->list + i;
 141                 struct object *o = parse_object(e->sha1);
 142                 if (o) {
 143                         o->flags |= PREREQ_MARK;
 144                         add_pending_object(&revs, o, e->name);
 145                         continue;
 146                 }
 147                 if (++ret == 1)
 148                         error(message);
 149                 error("%s %s", sha1_to_hex(e->sha1), e->name);
 150         }
 151         if (revs.pending.nr != p->nr)
 152                 return ret;
 153         req_nr = revs.pending.nr;
 154         setup_revisions(2, argv, &revs, NULL);
 155
 156         memset(&refs, 0, sizeof(struct object_array));
 157         for (i = 0; i < revs.pending.nr; i++) {
 158                 struct object_array_entry *e = revs.pending.objects + i;
 159                 add_object_array(e->item, e->name, &refs);
 160         }
 161
 162         prepare_revision_walk(&revs);
 163
 164         i = req_nr;
 165         while (i && (commit = get_revision(&revs)))
 166                 if (commit->object.flags & PREREQ_MARK)
 167                         i--;
 168
 169         for (i = 0; i < req_nr; i++)
 170                 if (!(refs.objects[i].item->flags & SHOWN)) {
 171                         if (++ret == 1)
 172                                 error(message);
 173                         error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
 174                                 refs.objects[i].name);
 175                 }
 176
 177         for (i = 0; i < refs.nr; i++)
 178                 clear_commit_marks((struct commit *)refs.objects[i].item, -1);
 179
 180         if (verbose) {
 181                 struct ref_list *r;
 182
 183                 r = &header->references;
 184                 printf("The bundle contains %d ref%s\n",
 185                        r->nr, (1 < r->nr) ? "s" : "");
 186                 list_refs(r, 0, NULL);
 187                 r = &header->prerequisites;
 188                 printf("The bundle requires these %d ref%s\n",
 189                        r->nr, (1 < r->nr) ? "s" : "");
 190                 list_refs(r, 0, NULL);
 191         }
 192         return ret;
 193 }
 194
 195 static int list_heads(struct bundle_header *header, int argc, const char **argv)
 196 {
 197         return list_refs(&header->references, argc, argv);
 198 }
 199
 200 static int create_bundle(struct bundle_header *header, const char *path,
 201                 int argc, const char **argv)
 202 {
 203         int bundle_fd = -1;
 204         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 205         const char **argv_pack = xmalloc(5 * sizeof(const char *));
 206         int i, ref_count = 0;
 207         char buffer[1024];
 208         struct rev_info revs;
 209         struct child_process rls;
 210
 211         /*
 212          * NEEDSWORK: this should use something like lock-file
 213          * to create temporary that is cleaned up upon error.
 214          */
 215         bundle_fd = (!strcmp(path, "-") ? 1 :
 216                         open(path, O_CREAT | O_EXCL | O_WRONLY, 0666));
 217         if (bundle_fd < 0)
 218                 return error("Could not create '%s': %s", path, strerror(errno));
 219
 220         /* write signature */
 221         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 222
 223         /* init revs to list objects for pack-objects later */
 224         save_commit_buffer = 0;
 225         init_revisions(&revs, NULL);
 226
 227         /* write prerequisites */
 228         memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
 229         argv_boundary[0] = "rev-list";
 230         argv_boundary[1] = "--boundary";
 231         argv_boundary[2] = "--pretty=oneline";
 232         argv_boundary[argc + 2] = NULL;
 233         memset(&rls, 0, sizeof(rls));
 234         rls.argv = argv_boundary;
 235         rls.out = -1;
 236         rls.git_cmd = 1;
 237         if (start_command(&rls))
 238                 return -1;
 239         while ((i = read_string(rls.out, buffer, sizeof(buffer))) > 0) {
 240                 unsigned char sha1[20];
 241                 if (buffer[0] == '-') {
 242                         write_or_die(bundle_fd, buffer, i);
 243                         if (!get_sha1_hex(buffer + 1, sha1)) {
 244                                 struct object *object = parse_object(sha1);
 245                                 object->flags |= UNINTERESTING;
 246                                 add_pending_object(&revs, object, buffer);
 247                         }
 248                 } else if (!get_sha1_hex(buffer, sha1)) {
 249                         struct object *object = parse_object(sha1);
 250                         object->flags |= SHOWN;
 251                 }
 252         }
 253         if (finish_command(&rls))
 254                 return error("rev-list died");
 255
 256         /* write references */
 257         argc = setup_revisions(argc, argv, &revs, NULL);
 258         if (argc > 1)
 259                 return error("unrecognized argument: %s'", argv[1]);
 260
 261         for (i = 0; i < revs.pending.nr; i++) {
 262                 struct object_array_entry *e = revs.pending.objects + i;
 263                 unsigned char sha1[20];
 264                 char *ref;
 265
 266                 if (e->item->flags & UNINTERESTING)
 267                         continue;
 268                 if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 269                         continue;
 270                 /*
 271                  * Make sure the refs we wrote out is correct; --max-count and
 272                  * other limiting options could have prevented all the tips
 273                  * from getting output.
 274                  *
 275                  * Non commit objects such as tags and blobs do not have
 276                  * this issue as they are not affected by those extra
 277                  * constraints.
 278                  */
 279                 if (!(e->item->flags & SHOWN) && e->item->type == OBJ_COMMIT) {
 280                         warning("ref '%s' is excluded by the rev-list options",
 281                                 e->name);
 282                         free(ref);
 283                         continue;
 284                 }
 285                 /*
 286                  * If you run "git bundle create bndl v1.0..v2.0", the
 287                  * name of the positive ref is "v2.0" but that is the
 288                  * commit that is referenced by the tag, and not the tag
 289                  * itself.
 290                  */
 291                 if (hashcmp(sha1, e->item->sha1)) {
 292                         /*
 293                          * Is this the positive end of a range expressed
 294                          * in terms of a tag (e.g. v2.0 from the range
 295                          * "v1.0..v2.0")?
 296                          */
 297                         struct commit *one = lookup_commit_reference(sha1);
 298                         struct object *obj;
 299
 300                         if (e->item == &(one->object)) {
 301                                 /*
 302                                  * Need to include e->name as an
 303                                  * independent ref to the pack-objects
 304                                  * input, so that the tag is included
 305                                  * in the output; otherwise we would
 306                                  * end up triggering "empty bundle"
 307                                  * error.
 308                                  */
 309                                 obj = parse_object(sha1);
 310                                 obj->flags |= SHOWN;
 311                                 add_pending_object(&revs, obj, e->name);
 312                         }
 313                         free(ref);
 314                         continue;
 315                 }
 316
 317                 ref_count++;
 318                 write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 319                 write_or_die(bundle_fd, " ", 1);
 320                 write_or_die(bundle_fd, ref, strlen(ref));
 321                 write_or_die(bundle_fd, "\n", 1);
 322                 free(ref);
 323         }
 324         if (!ref_count)
 325                 die ("Refusing to create empty bundle.");
 326
 327         /* end header */
 328         write_or_die(bundle_fd, "\n", 1);
 329
 330         /* write pack */
 331         argv_pack[0] = "pack-objects";
 332         argv_pack[1] = "--all-progress";
 333         argv_pack[2] = "--stdout";
 334         argv_pack[3] = "--thin";
 335         argv_pack[4] = NULL;
 336         memset(&rls, 0, sizeof(rls));
 337         rls.argv = argv_pack;
 338         rls.in = -1;
 339         rls.out = bundle_fd;
 340         rls.git_cmd = 1;
 341         if (start_command(&rls))
 342                 return error("Could not spawn pack-objects");
 343         for (i = 0; i < revs.pending.nr; i++) {
 344                 struct object *object = revs.pending.objects[i].item;
 345                 if (object->flags & UNINTERESTING)
 346                         write(rls.in, "^", 1);
 347                 write(rls.in, sha1_to_hex(object->sha1), 40);
 348                 write(rls.in, "\n", 1);
 349         }
 350         if (finish_command(&rls))
 351                 return error ("pack-objects died");
 352         return 0;
 353 }
 354
 355 static int unbundle(struct bundle_header *header, int bundle_fd,
 356                 int argc, const char **argv)
 357 {
 358         const char *argv_index_pack[] = {"index-pack",
 359                 "--fix-thin", "--stdin", NULL};
 360         struct child_process ip;
 361
 362         if (verify_bundle(header, 0))
 363                 return -1;
 364         memset(&ip, 0, sizeof(ip));
 365         ip.argv = argv_index_pack;
 366         ip.in = bundle_fd;
 367         ip.no_stdout = 1;
 368         ip.git_cmd = 1;
 369         if (run_command(&ip))
 370                 return error("index-pack died");
 371         return list_heads(header, argc, argv);
 372 }
 373
 374 int cmd_bundle(int argc, const char **argv, const char *prefix)
 375 {
 376         struct bundle_header header;
 377         int nongit = 0;
 378         const char *cmd, *bundle_file;
 379         int bundle_fd = -1;
 380         char buffer[PATH_MAX];
 381
 382         if (argc < 3)
 383                 usage(bundle_usage);
 384
 385         cmd = argv[1];
 386         bundle_file = argv[2];
 387         argc -= 2;
 388         argv += 2;
 389
 390         prefix = setup_git_directory_gently(&nongit);
 391         if (prefix && bundle_file[0] != '/') {
 392                 snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 393                 bundle_file = buffer;
 394         }
 395
 396         memset(&header, 0, sizeof(header));
 397         if (strcmp(cmd, "create") &&
 398                         (bundle_fd = read_header(bundle_file, &header)) < 0)
 399                 return 1;
 400
 401         if (!strcmp(cmd, "verify")) {
 402                 close(bundle_fd);
 403                 if (verify_bundle(&header, 1))
 404                         return 1;
 405                 fprintf(stderr, "%s is okay\n", bundle_file);
 406                 return 0;
 407         }
 408         if (!strcmp(cmd, "list-heads")) {
 409                 close(bundle_fd);
 410                 return !!list_heads(&header, argc, argv);
 411         }
 412         if (!strcmp(cmd, "create")) {
 413                 if (nongit)
 414                         die("Need a repository to create a bundle.");
 415                 return !!create_bundle(&header, bundle_file, argc, argv);
 416         } else if (!strcmp(cmd, "unbundle")) {
 417                 if (nongit)
 418                         die("Need a repository to unbundle.");
 419                 return !!unbundle(&header, bundle_fd, argc, argv);
 420         } else
 421                 usage(bundle_usage);
 422 }