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