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 "run-command.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                         warning("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 static int list_refs(struct ref_list *r, int argc, const char **argv)
 103 {
 104         int i;
 105
 106         for (i = 0; i < r->nr; i++) {
 107                 if (argc > 1) {
 108                         int j;
 109                         for (j = 1; j < argc; j++)
 110                                 if (!strcmp(r->list[i].name, argv[j]))
 111                                         break;
 112                         if (j == argc)
 113                                 continue;
 114                 }
 115                 printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 116                                 r->list[i].name);
 117         }
 118         return 0;
 119 }
 120
 121 #define PREREQ_MARK (1u<<16)
 122
 123 static int verify_bundle(struct bundle_header *header, int verbose)
 124 {
 125         /*
 126          * Do fast check, then if any prereqs are missing then go line by line
 127          * to be verbose about the errors
 128          */
 129         struct ref_list *p = &header->prerequisites;
 130         struct rev_info revs;
 131         const char *argv[] = {NULL, "--all"};
 132         struct object_array refs;
 133         struct commit *commit;
 134         int i, ret = 0, req_nr;
 135         const char *message = "Repository lacks these prerequisite commits:";
 136
 137         init_revisions(&revs, NULL);
 138         for (i = 0; i < p->nr; i++) {
 139                 struct ref_list_entry *e = p->list + i;
 140                 struct object *o = parse_object(e->sha1);
 141                 if (o) {
 142                         o->flags |= PREREQ_MARK;
 143                         add_pending_object(&revs, o, e->name);
 144                         continue;
 145                 }
 146                 if (++ret == 1)
 147                         error(message);
 148                 error("%s %s", sha1_to_hex(e->sha1), e->name);
 149         }
 150         if (revs.pending.nr != p->nr)
 151                 return ret;
 152         req_nr = revs.pending.nr;
 153         setup_revisions(2, argv, &revs, NULL);
 154
 155         memset(&refs, 0, sizeof(struct object_array));
 156         for (i = 0; i < revs.pending.nr; i++) {
 157                 struct object_array_entry *e = revs.pending.objects + i;
 158                 add_object_array(e->item, e->name, &refs);
 159         }
 160
 161         prepare_revision_walk(&revs);
 162
 163         i = req_nr;
 164         while (i && (commit = get_revision(&revs)))
 165                 if (commit->object.flags & PREREQ_MARK)
 166                         i--;
 167
 168         for (i = 0; i < req_nr; i++)
 169                 if (!(refs.objects[i].item->flags & SHOWN)) {
 170                         if (++ret == 1)
 171                                 error(message);
 172                         error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
 173                                 refs.objects[i].name);
 174                 }
 175
 176         for (i = 0; i < refs.nr; i++)
 177                 clear_commit_marks((struct commit *)refs.objects[i].item, -1);
 178
 179         if (verbose) {
 180                 struct ref_list *r;
 181
 182                 r = &header->references;
 183                 printf("The bundle contains %d ref%s\n",
 184                        r->nr, (1 < r->nr) ? "s" : "");
 185                 list_refs(r, 0, NULL);
 186                 r = &header->prerequisites;
 187                 printf("The bundle requires these %d ref%s\n",
 188                        r->nr, (1 < r->nr) ? "s" : "");
 189                 list_refs(r, 0, NULL);
 190         }
 191         return ret;
 192 }
 193
 194 static int list_heads(struct bundle_header *header, int argc, const char **argv)
 195 {
 196         return list_refs(&header->references, argc, argv);
 197 }
 198
 199 static int create_bundle(struct bundle_header *header, const char *path,
 200                 int argc, const char **argv)
 201 {
 202         int bundle_fd = -1;
 203         const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 204         const char **argv_pack = xmalloc(5 * sizeof(const char *));
 205         int i, ref_count = 0;
 206         char buffer[1024];
 207         struct rev_info revs;
 208         struct child_process rls;
 209
 210         bundle_fd = (!strcmp(path, "-") ? 1 :
 211                         open(path, O_CREAT | O_EXCL | O_WRONLY, 0666));
 212         if (bundle_fd < 0)
 213                 return error("Could not create '%s': %s", path, strerror(errno));
 214
 215         /* write signature */
 216         write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 217
 218         /* init revs to list objects for pack-objects later */
 219         save_commit_buffer = 0;
 220         init_revisions(&revs, NULL);
 221
 222         /* write prerequisites */
 223         memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
 224         argv_boundary[0] = "rev-list";
 225         argv_boundary[1] = "--boundary";
 226         argv_boundary[2] = "--pretty=oneline";
 227         argv_boundary[argc + 2] = NULL;
 228         memset(&rls, 0, sizeof(rls));
 229         rls.argv = argv_boundary;
 230         rls.out = -1;
 231         rls.git_cmd = 1;
 232         if (start_command(&rls))
 233                 return -1;
 234         while ((i = read_string(rls.out, buffer, sizeof(buffer))) > 0) {
 235                 unsigned char sha1[20];
 236                 if (buffer[0] == '-') {
 237                         write_or_die(bundle_fd, buffer, i);
 238                         if (!get_sha1_hex(buffer + 1, sha1)) {
 239                                 struct object *object = parse_object(sha1);
 240                                 object->flags |= UNINTERESTING;
 241                                 add_pending_object(&revs, object, buffer);
 242                         }
 243                 } else if (!get_sha1_hex(buffer, sha1)) {
 244                         struct object *object = parse_object(sha1);
 245                         object->flags |= SHOWN;
 246                 }
 247         }
 248         if (finish_command(&rls))
 249                 return error("rev-list died");
 250
 251         /* write references */
 252         argc = setup_revisions(argc, argv, &revs, NULL);
 253         if (argc > 1)
 254                 return error("unrecognized argument: %s'", argv[1]);
 255
 256         for (i = 0; i < revs.pending.nr; i++) {
 257                 struct object_array_entry *e = revs.pending.objects + i;
 258                 unsigned char sha1[20];
 259                 char *ref;
 260
 261                 if (e->item->flags & UNINTERESTING)
 262                         continue;
 263                 if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 264                         continue;
 265                 /*
 266                  * Make sure the refs we wrote out is correct; --max-count and
 267                  * other limiting options could have prevented all the tips
 268                  * from getting output.
 269                  */
 270                 if (!(e->item->flags & SHOWN)) {
 271                         warning("ref '%s' is excluded by the rev-list options",
 272                                 e->name);
 273                         continue;
 274                 }
 275                 ref_count++;
 276                 write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 277                 write_or_die(bundle_fd, " ", 1);
 278                 write_or_die(bundle_fd, ref, strlen(ref));
 279                 write_or_die(bundle_fd, "\n", 1);
 280                 free(ref);
 281         }
 282         if (!ref_count)
 283                 die ("Refusing to create empty bundle.");
 284
 285         /* end header */
 286         write_or_die(bundle_fd, "\n", 1);
 287
 288         /* write pack */
 289         argv_pack[0] = "pack-objects";
 290         argv_pack[1] = "--all-progress";
 291         argv_pack[2] = "--stdout";
 292         argv_pack[3] = "--thin";
 293         argv_pack[4] = NULL;
 294         memset(&rls, 0, sizeof(rls));
 295         rls.argv = argv_pack;
 296         rls.in = -1;
 297         rls.out = bundle_fd;
 298         rls.git_cmd = 1;
 299         if (start_command(&rls))
 300                 return error("Could not spawn pack-objects");
 301         for (i = 0; i < revs.pending.nr; i++) {
 302                 struct object *object = revs.pending.objects[i].item;
 303                 if (object->flags & UNINTERESTING)
 304                         write(rls.in, "^", 1);
 305                 write(rls.in, sha1_to_hex(object->sha1), 40);
 306                 write(rls.in, "\n", 1);
 307         }
 308         if (finish_command(&rls))
 309                 return error ("pack-objects died");
 310         return 0;
 311 }
 312
 313 static int unbundle(struct bundle_header *header, int bundle_fd,
 314                 int argc, const char **argv)
 315 {
 316         const char *argv_index_pack[] = {"index-pack",
 317                 "--fix-thin", "--stdin", NULL};
 318         struct child_process ip;
 319
 320         if (verify_bundle(header, 0))
 321                 return -1;
 322         memset(&ip, 0, sizeof(ip));
 323         ip.argv = argv_index_pack;
 324         ip.in = bundle_fd;
 325         ip.no_stdout = 1;
 326         ip.git_cmd = 1;
 327         if (run_command(&ip))
 328                 return error("index-pack died");
 329         return list_heads(header, argc, argv);
 330 }
 331
 332 int cmd_bundle(int argc, const char **argv, const char *prefix)
 333 {
 334         struct bundle_header header;
 335         int nongit = 0;
 336         const char *cmd, *bundle_file;
 337         int bundle_fd = -1;
 338         char buffer[PATH_MAX];
 339
 340         if (argc < 3)
 341                 usage(bundle_usage);
 342
 343         cmd = argv[1];
 344         bundle_file = argv[2];
 345         argc -= 2;
 346         argv += 2;
 347
 348         prefix = setup_git_directory_gently(&nongit);
 349         if (prefix && bundle_file[0] != '/') {
 350                 snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 351                 bundle_file = buffer;
 352         }
 353
 354         memset(&header, 0, sizeof(header));
 355         if (strcmp(cmd, "create") &&
 356                         (bundle_fd = read_header(bundle_file, &header)) < 0)
 357                 return 1;
 358
 359         if (!strcmp(cmd, "verify")) {
 360                 close(bundle_fd);
 361                 if (verify_bundle(&header, 1))
 362                         return 1;
 363                 fprintf(stderr, "%s is okay\n", bundle_file);
 364                 return 0;
 365         }
 366         if (!strcmp(cmd, "list-heads")) {
 367                 close(bundle_fd);
 368                 return !!list_heads(&header, argc, argv);
 369         }
 370         if (!strcmp(cmd, "create")) {
 371                 if (nongit)
 372                         die("Need a repository to create a bundle.");
 373                 return !!create_bundle(&header, bundle_file, argc, argv);
 374         } else if (!strcmp(cmd, "unbundle")) {
 375                 if (nongit)
 376                         die("Need a repository to unbundle.");
 377                 return !!unbundle(&header, bundle_fd, argc, argv);
 378         } else
 379                 usage(bundle_usage);
 380 }