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 verify_bundle(struct bundle_header *header)
 164 {
 165         /*
 166          * Do fast check, then if any prereqs are missing then go line by line
 167          * to be verbose about the errors
 168          */
 169         struct ref_list *p = &header->prerequisites;
 170         struct rev_info revs;
 171         const char *argv[] = {NULL, "--all"};
 172         struct object_array refs;
 173         struct commit *commit;
 174         int i, ret = 0, req_nr;
 175         const char *message = "Repository lacks these prerequisite commits:";
 176
 177         init_revisions(&revs, NULL);
 178         for (i = 0; i < p->nr; i++) {
 179                 struct ref_list_entry *e = p->list + i;
 180                 struct object *o = parse_object(e->sha1);
 181                 if (o) {
 182                         o->flags |= BOUNDARY_SHOW;
 183                         add_pending_object(&revs, o, e->name);
 184                         continue;
 185                 }
 186                 if (++ret == 1)
 187                         error(message);
 188                 error("%s %s", sha1_to_hex(e->sha1), e->name);
 189         }
 190         if (revs.pending.nr == 0)
 191                 return ret;
 192         req_nr = revs.pending.nr;
 193         setup_revisions(2, argv, &revs, NULL);
 194
 195         memset(&refs, 0, sizeof(struct object_array));
 196         for (i = 0; i < revs.pending.nr; i++) {
 197                 struct object_array_entry *e = revs.pending.objects + i;
 198                 add_object_array(e->item, e->name, &refs);
 199         }
 200
 201         prepare_revision_walk(&revs);
 202
 203         i = req_nr;
 204         while (i && (commit = get_revision(&revs)))
 205                 if (commit->object.flags & BOUNDARY_SHOW)
 206                         i--;
 207
 208         for (i = 0; i < req_nr; i++)
 209                 if (!(refs.objects[i].item->flags & SHOWN)) {
 210                         if (++ret == 1)
 211                                 error(message);
 212                         error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
 213                                 refs.objects[i].name);
 214                 }
 215
 216         for (i = 0; i < refs.nr; i++)
 217                 clear_commit_marks((struct commit *)refs.objects[i].item, -1);
 218
 219         return ret;
 220 }
 221
 222 static int list_heads(struct bundle_header *header, int argc, const char **argv)
 223 {
 224         int i;
 225         struct ref_list *r = &header->references;
 226
 227         for (i = 0; i < r->nr; i++) {
 228                 if (argc > 1) {
 229                         int j;
 230                         for (j = 1; j < argc; j++)
 231                                 if (!strcmp(r->list[i].name, argv[j]))
 232                                         break;
 233                         if (j == argc)
 234                                 continue;
 235                 }
 236                 printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 237                                 r->list[i].name);
 238         }
 239         return 0;
 240 }
 241
 242 static void show_commit(struct commit *commit)
 243 {
 244         write_or_die(1, sha1_to_hex(commit->object.sha1), 40);
 245         write_or_die(1, "\n", 1);
 246         if (commit->parents) {
 247                 free_commit_list(commit->parents);
 248                 commit->parents = NULL;
 249         }
 250 }
 251
 252 static void show_object(struct object_array_entry *p)
 253 {
 254         /* An object with name "foo\n0000000..." can be used to
 255          * confuse downstream git-pack-objects very badly.
 256          */
 257         const char *ep = strchr(p->name, '\n');
 258         int len = ep ? ep - p->name : strlen(p->name);
 259         write_or_die(1, sha1_to_hex(p->item->sha1), 40);
 260         write_or_die(1, " ", 1);
 261         if (len)
 262                 write_or_die(1, p->name, len);
 263         write_or_die(1, "\n", 1);
 264 }
 265
 266 static void show_edge(struct commit *commit)
 267 {
 268         ; /* nothing to do */
 269 }
 270
 271 static int create_bundle(struct bundle_header *header, const char *path,
 272                 int argc, const char **argv)
 273 {
 274         int bundle_fd = -1;
 275         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 276         const char **argv_pack = xmalloc(4 * sizeof(const char *));
 277         int pid, in, out, i, status;
 278         char buffer[1024];
 279         struct rev_info revs;
 280
 281         bundle_fd = (!strcmp(path, "-") ? 1 :
 282                         open(path, O_CREAT | O_WRONLY, 0666));
 283         if (bundle_fd < 0)
 284                 return error("Could not write to '%s'", path);
 285
 286         /* write signature */
 287         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 288
 289         /* write prerequisites */
 290         memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
 291         argv_boundary[0] = "rev-list";
 292         argv_boundary[1] = "--boundary";
 293         argv_boundary[2] = "--pretty=oneline";
 294         argv_boundary[argc + 2] = NULL;
 295         out = -1;
 296         pid = fork_with_pipe(argv_boundary, NULL, &out);
 297         if (pid < 0)
 298                 return -1;
 299         while ((i = read_string(out, buffer, sizeof(buffer))) > 0)
 300                 if (buffer[0] == '-')
 301                         write_or_die(bundle_fd, buffer, i);
 302         while ((i = waitpid(pid, &status, 0)) < 0)
 303                 if (errno != EINTR)
 304                         return error("rev-list died");
 305         if (!WIFEXITED(status) || WEXITSTATUS(status))
 306                 return error("rev-list died %d", WEXITSTATUS(status));
 307
 308         /* write references */
 309         save_commit_buffer = 0;
 310         init_revisions(&revs, NULL);
 311         revs.tag_objects = 1;
 312         revs.tree_objects = 1;
 313         revs.blob_objects = 1;
 314         argc = setup_revisions(argc, argv, &revs, NULL);
 315         if (argc > 1)
 316                 return error("unrecognized argument: %s'", argv[1]);
 317         for (i = 0; i < revs.pending.nr; i++) {
 318                 struct object_array_entry *e = revs.pending.objects + i;
 319                 if (!(e->item->flags & UNINTERESTING)) {
 320                         unsigned char sha1[20];
 321                         char *ref;
 322                         if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 323                                 continue;
 324                         write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 325                         write_or_die(bundle_fd, " ", 1);
 326                         write_or_die(bundle_fd, ref, strlen(ref));
 327                         write_or_die(bundle_fd, "\n", 1);
 328                         free(ref);
 329                 }
 330         }
 331
 332         /* end header */
 333         write_or_die(bundle_fd, "\n", 1);
 334
 335         /* write pack */
 336         argv_pack[0] = "pack-objects";
 337         argv_pack[1] = "--all-progress";
 338         argv_pack[2] = "--stdout";
 339         argv_pack[3] = NULL;
 340         in = -1;
 341         out = bundle_fd;
 342         pid = fork_with_pipe(argv_pack, &in, &out);
 343         if (pid < 0)
 344                 return error("Could not spawn pack-objects");
 345         close(1);
 346         dup2(in, 1);
 347         close(in);
 348         prepare_revision_walk(&revs);
 349         mark_edges_uninteresting(revs.commits, &revs, show_edge);
 350         traverse_commit_list(&revs, show_commit, show_object);
 351         close(1);
 352         while (waitpid(pid, &status, 0) < 0)
 353                 if (errno != EINTR)
 354                         return -1;
 355         if (!WIFEXITED(status) || WEXITSTATUS(status))
 356                 return error ("pack-objects died");
 357         return 0;
 358 }
 359
 360 static int unbundle(struct bundle_header *header, int bundle_fd,
 361                 int argc, const char **argv)
 362 {
 363         const char *argv_index_pack[] = {"index-pack", "--stdin", NULL};
 364         int pid, status, dev_null;
 365
 366         if (verify_bundle(header))
 367                 return -1;
 368         dev_null = open("/dev/null", O_WRONLY);
 369         pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null);
 370         if (pid < 0)
 371                 return error("Could not spawn index-pack");
 372         while (waitpid(pid, &status, 0) < 0)
 373                 if (errno != EINTR)
 374                         return error("index-pack died");
 375         if (!WIFEXITED(status) || WEXITSTATUS(status))
 376                 return error("index-pack exited with status %d",
 377                                 WEXITSTATUS(status));
 378         return list_heads(header, argc, argv);
 379 }
 380
 381 int cmd_bundle(int argc, const char **argv, const char *prefix)
 382 {
 383         struct bundle_header header;
 384         int nongit = 0;
 385         const char *cmd, *bundle_file;
 386         int bundle_fd = -1;
 387         char buffer[PATH_MAX];
 388
 389         if (argc < 3)
 390                 usage(bundle_usage);
 391
 392         cmd = argv[1];
 393         bundle_file = argv[2];
 394         argc -= 2;
 395         argv += 2;
 396
 397         prefix = setup_git_directory_gently(&nongit);
 398         if (prefix && bundle_file[0] != '/') {
 399                 snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 400                 bundle_file = buffer;
 401         }
 402
 403         memset(&header, 0, sizeof(header));
 404         if (strcmp(cmd, "create") &&
 405                         !(bundle_fd = read_header(bundle_file, &header)))
 406                 return 1;
 407
 408         if (!strcmp(cmd, "verify")) {
 409                 close(bundle_fd);
 410                 if (verify_bundle(&header))
 411                         return 1;
 412                 fprintf(stderr, "%s is okay\n", bundle_file);
 413                 return 0;
 414         }
 415         if (!strcmp(cmd, "list-heads")) {
 416                 close(bundle_fd);
 417                 return !!list_heads(&header, argc, argv);
 418         }
 419         if (!strcmp(cmd, "create")) {
 420                 if (nongit)
 421                         die("Need a repository to create a bundle.");
 422                 return !!create_bundle(&header, bundle_file, argc, argv);
 423         } else if (!strcmp(cmd, "unbundle")) {
 424                 if (nongit)
 425                         die("Need a repository to unbundle.");
 426                 return !!unbundle(&header, bundle_fd, argc, argv);
 427         } else
 428                 usage(bundle_usage);
 429 }
 430