Andrew's git - gitweb.git/blob

   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
  16static const char *bundle_usage="git-bundle (create <bundle> <git-rev-list args> | verify <bundle> | list-heads <bundle> [refname]... | unbundle <bundle> [refname]... )";
  17
  18static const char bundle_signature[] = "# v2 git bundle\n";
  19
  20struct ref_list {
  21        unsigned int nr, alloc;
  22        struct ref_list_entry {
  23                unsigned char sha1[20];
  24                char *name;
  25        } *list;
  26};
  27
  28static 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
  41struct bundle_header {
  42        struct ref_list prerequisites;
  43        struct ref_list references;
  44};
  45
  46/* this function returns the length of the string */
  47static 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 */
  66static 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 */
 103static 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
 163static int list_refs(struct ref_list *r, int argc, const char **argv)
 164{
 165        int i;
 166
 167        for (i = 0; i < r->nr; i++) {
 168                if (argc > 1) {
 169                        int j;
 170                        for (j = 1; j < argc; j++)
 171                                if (!strcmp(r->list[i].name, argv[j]))
 172                                        break;
 173                        if (j == argc)
 174                                continue;
 175                }
 176                printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 177                                r->list[i].name);
 178        }
 179        return 0;
 180}
 181
 182#define PREREQ_MARK (1u<<16)
 183
 184static int verify_bundle(struct bundle_header *header, int verbose)
 185{
 186        /*
 187         * Do fast check, then if any prereqs are missing then go line by line
 188         * to be verbose about the errors
 189         */
 190        struct ref_list *p = &header->prerequisites;
 191        struct rev_info revs;
 192        const char *argv[] = {NULL, "--all"};
 193        struct object_array refs;
 194        struct commit *commit;
 195        int i, ret = 0, req_nr;
 196        const char *message = "Repository lacks these prerequisite commits:";
 197
 198        init_revisions(&revs, NULL);
 199        for (i = 0; i < p->nr; i++) {
 200                struct ref_list_entry *e = p->list + i;
 201                struct object *o = parse_object(e->sha1);
 202                if (o) {
 203                        o->flags |= PREREQ_MARK;
 204                        add_pending_object(&revs, o, e->name);
 205                        continue;
 206                }
 207                if (++ret == 1)
 208                        error(message);
 209                error("%s %s", sha1_to_hex(e->sha1), e->name);
 210        }
 211        if (revs.pending.nr != p->nr)
 212                return ret;
 213        req_nr = revs.pending.nr;
 214        setup_revisions(2, argv, &revs, NULL);
 215
 216        memset(&refs, 0, sizeof(struct object_array));
 217        for (i = 0; i < revs.pending.nr; i++) {
 218                struct object_array_entry *e = revs.pending.objects + i;
 219                add_object_array(e->item, e->name, &refs);
 220        }
 221
 222        prepare_revision_walk(&revs);
 223
 224        i = req_nr;
 225        while (i && (commit = get_revision(&revs)))
 226                if (commit->object.flags & PREREQ_MARK)
 227                        i--;
 228
 229        for (i = 0; i < req_nr; i++)
 230                if (!(refs.objects[i].item->flags & SHOWN)) {
 231                        if (++ret == 1)
 232                                error(message);
 233                        error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
 234                                refs.objects[i].name);
 235                }
 236
 237        for (i = 0; i < refs.nr; i++)
 238                clear_commit_marks((struct commit *)refs.objects[i].item, -1);
 239
 240        if (verbose) {
 241                struct ref_list *r;
 242
 243                r = &header->references;
 244                printf("The bundle contains %d ref%s\n",
 245                       r->nr, (1 < r->nr) ? "s" : "");
 246                list_refs(r, 0, NULL);
 247                r = &header->prerequisites;
 248                printf("The bundle requires these %d ref%s\n",
 249                       r->nr, (1 < r->nr) ? "s" : "");
 250                list_refs(r, 0, NULL);
 251        }
 252        return ret;
 253}
 254
 255static int list_heads(struct bundle_header *header, int argc, const char **argv)
 256{
 257        return list_refs(&header->references, argc, argv);
 258}
 259
 260static int create_bundle(struct bundle_header *header, const char *path,
 261                int argc, const char **argv)
 262{
 263        int bundle_fd = -1;
 264        const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
 265        const char **argv_pack = xmalloc(5 * sizeof(const char *));
 266        int pid, in, out, i, status, ref_count = 0;
 267        char buffer[1024];
 268        struct rev_info revs;
 269
 270        bundle_fd = (!strcmp(path, "-") ? 1 :
 271                        open(path, O_CREAT | O_EXCL | O_WRONLY, 0666));
 272        if (bundle_fd < 0)
 273                return error("Could not create '%s': %s", path, strerror(errno));
 274
 275        /* write signature */
 276        write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 277
 278        /* init revs to list objects for pack-objects later */
 279        save_commit_buffer = 0;
 280        init_revisions(&revs, NULL);
 281
 282        /* write prerequisites */
 283        memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
 284        argv_boundary[0] = "rev-list";
 285        argv_boundary[1] = "--boundary";
 286        argv_boundary[2] = "--pretty=oneline";
 287        argv_boundary[argc + 2] = NULL;
 288        out = -1;
 289        pid = fork_with_pipe(argv_boundary, NULL, &out);
 290        if (pid < 0)
 291                return -1;
 292        while ((i = read_string(out, buffer, sizeof(buffer))) > 0) {
 293                unsigned char sha1[20];
 294                if (buffer[0] == '-') {
 295                        write_or_die(bundle_fd, buffer, i);
 296                        if (!get_sha1_hex(buffer + 1, sha1)) {
 297                                struct object *object = parse_object(sha1);
 298                                object->flags |= UNINTERESTING;
 299                                add_pending_object(&revs, object, buffer);
 300                        }
 301                } else if (!get_sha1_hex(buffer, sha1)) {
 302                        struct object *object = parse_object(sha1);
 303                        object->flags |= SHOWN;
 304                }
 305        }
 306        while ((i = waitpid(pid, &status, 0)) < 0)
 307                if (errno != EINTR)
 308                        return error("rev-list died");
 309        if (!WIFEXITED(status) || WEXITSTATUS(status))
 310                return error("rev-list died %d", WEXITSTATUS(status));
 311
 312        /* write references */
 313        argc = setup_revisions(argc, argv, &revs, NULL);
 314        if (argc > 1)
 315                return error("unrecognized argument: %s'", argv[1]);
 316
 317        for (i = 0; i < revs.pending.nr; i++) {
 318                struct object_array_entry *e = revs.pending.objects + i;
 319                unsigned char sha1[20];
 320                char *ref;
 321
 322                if (e->item->flags & UNINTERESTING)
 323                        continue;
 324                if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 325                        continue;
 326                /*
 327                 * Make sure the refs we wrote out is correct; --max-count and
 328                 * other limiting options could have prevented all the tips
 329                 * from getting output.
 330                 */
 331                if (!(e->item->flags & SHOWN)) {
 332                        warn("ref '%s' is excluded by the rev-list options",
 333                                e->name);
 334                        continue;
 335                }
 336                ref_count++;
 337                write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 338                write_or_die(bundle_fd, " ", 1);
 339                write_or_die(bundle_fd, ref, strlen(ref));
 340                write_or_die(bundle_fd, "\n", 1);
 341                free(ref);
 342        }
 343        if (!ref_count)
 344                die ("Refusing to create empty bundle.");
 345
 346        /* end header */
 347        write_or_die(bundle_fd, "\n", 1);
 348
 349        /* write pack */
 350        argv_pack[0] = "pack-objects";
 351        argv_pack[1] = "--all-progress";
 352        argv_pack[2] = "--stdout";
 353        argv_pack[3] = "--thin";
 354        argv_pack[4] = NULL;
 355        in = -1;
 356        out = bundle_fd;
 357        pid = fork_with_pipe(argv_pack, &in, &out);
 358        if (pid < 0)
 359                return error("Could not spawn pack-objects");
 360        for (i = 0; i < revs.pending.nr; i++) {
 361                struct object *object = revs.pending.objects[i].item;
 362                if (object->flags & UNINTERESTING)
 363                        write(in, "^", 1);
 364                write(in, sha1_to_hex(object->sha1), 40);
 365                write(in, "\n", 1);
 366        }
 367        close(in);
 368        while (waitpid(pid, &status, 0) < 0)
 369                if (errno != EINTR)
 370                        return -1;
 371        if (!WIFEXITED(status) || WEXITSTATUS(status))
 372                return error ("pack-objects died");
 373
 374        return status;
 375}
 376
 377static int unbundle(struct bundle_header *header, int bundle_fd,
 378                int argc, const char **argv)
 379{
 380        const char *argv_index_pack[] = {"index-pack",
 381                "--fix-thin", "--stdin", NULL};
 382        int pid, status, dev_null;
 383
 384        if (verify_bundle(header, 0))
 385                return -1;
 386        dev_null = open("/dev/null", O_WRONLY);
 387        if (dev_null < 0)
 388                return error("Could not open /dev/null");
 389        pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null);
 390        if (pid < 0)
 391                return error("Could not spawn index-pack");
 392        while (waitpid(pid, &status, 0) < 0)
 393                if (errno != EINTR)
 394                        return error("index-pack died");
 395        if (!WIFEXITED(status) || WEXITSTATUS(status))
 396                return error("index-pack exited with status %d",
 397                                WEXITSTATUS(status));
 398        return list_heads(header, argc, argv);
 399}
 400
 401int cmd_bundle(int argc, const char **argv, const char *prefix)
 402{
 403        struct bundle_header header;
 404        int nongit = 0;
 405        const char *cmd, *bundle_file;
 406        int bundle_fd = -1;
 407        char buffer[PATH_MAX];
 408
 409        if (argc < 3)
 410                usage(bundle_usage);
 411
 412        cmd = argv[1];
 413        bundle_file = argv[2];
 414        argc -= 2;
 415        argv += 2;
 416
 417        prefix = setup_git_directory_gently(&nongit);
 418        if (prefix && bundle_file[0] != '/') {
 419                snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 420                bundle_file = buffer;
 421        }
 422
 423        memset(&header, 0, sizeof(header));
 424        if (strcmp(cmd, "create") &&
 425                        (bundle_fd = read_header(bundle_file, &header)) < 0)
 426                return 1;
 427
 428        if (!strcmp(cmd, "verify")) {
 429                close(bundle_fd);
 430                if (verify_bundle(&header, 1))
 431                        return 1;
 432                fprintf(stderr, "%s is okay\n", bundle_file);
 433                return 0;
 434        }
 435        if (!strcmp(cmd, "list-heads")) {
 436                close(bundle_fd);
 437                return !!list_heads(&header, argc, argv);
 438        }
 439        if (!strcmp(cmd, "create")) {
 440                if (nongit)
 441                        die("Need a repository to create a bundle.");
 442                return !!create_bundle(&header, bundle_file, argc, argv);
 443        } else if (!strcmp(cmd, "unbundle")) {
 444                if (nongit)
 445                        die("Need a repository to unbundle.");
 446                return !!unbundle(&header, bundle_fd, argc, argv);
 447        } else
 448                usage(bundle_usage);
 449}