git.oblomov.eu Git - git/blob - builtin/fast-export.c

   1 /*
   2  * "git fast-export" builtin command
   3  *
   4  * Copyright (C) 2007 Johannes E. Schindelin
   5  */
   6 #include "builtin.h"
   7 #include "cache.h"
   8 #include "config.h"
   9 #include "refs.h"
  10 #include "refspec.h"
  11 #include "object-store.h"
  12 #include "commit.h"
  13 #include "object.h"
  14 #include "tag.h"
  15 #include "diff.h"
  16 #include "diffcore.h"
  17 #include "log-tree.h"
  18 #include "revision.h"
  19 #include "decorate.h"
  20 #include "string-list.h"
  21 #include "utf8.h"
  22 #include "parse-options.h"
  23 #include "quote.h"
  24 #include "remote.h"
  25 #include "blob.h"
  26 #include "commit-slab.h"
  27
  28 static const char *fast_export_usage[] = {
  29         N_("git fast-export [rev-list-opts]"),
  30         NULL
  31 };
  32
  33 static int progress;
  34 static enum { ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = ABORT;
  35 static enum { ERROR, DROP, REWRITE } tag_of_filtered_mode = ERROR;
  36 static int fake_missing_tagger;
  37 static int use_done_feature;
  38 static int no_data;
  39 static int full_tree;
  40 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  41 static struct refspec refspecs = REFSPEC_INIT_FETCH;
  42 static int anonymize;
  43 static struct revision_sources revision_sources;
  44
  45 static int parse_opt_signed_tag_mode(const struct option *opt,
  46                                      const char *arg, int unset)
  47 {
  48         if (unset || !strcmp(arg, "abort"))
  49                 signed_tag_mode = ABORT;
  50         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  51                 signed_tag_mode = VERBATIM;
  52         else if (!strcmp(arg, "warn"))
  53                 signed_tag_mode = WARN;
  54         else if (!strcmp(arg, "warn-strip"))
  55                 signed_tag_mode = WARN_STRIP;
  56         else if (!strcmp(arg, "strip"))
  57                 signed_tag_mode = STRIP;
  58         else
  59                 return error("Unknown signed-tags mode: %s", arg);
  60         return 0;
  61 }
  62
  63 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  64                                           const char *arg, int unset)
  65 {
  66         if (unset || !strcmp(arg, "abort"))
  67                 tag_of_filtered_mode = ERROR;
  68         else if (!strcmp(arg, "drop"))
  69                 tag_of_filtered_mode = DROP;
  70         else if (!strcmp(arg, "rewrite"))
  71                 tag_of_filtered_mode = REWRITE;
  72         else
  73                 return error("Unknown tag-of-filtered mode: %s", arg);
  74         return 0;
  75 }
  76
  77 static struct decoration idnums;
  78 static uint32_t last_idnum;
  79
  80 static int has_unshown_parent(struct commit *commit)
  81 {
  82         struct commit_list *parent;
  83
  84         for (parent = commit->parents; parent; parent = parent->next)
  85                 if (!(parent->item->object.flags & SHOWN) &&
  86                     !(parent->item->object.flags & UNINTERESTING))
  87                         return 1;
  88         return 0;
  89 }
  90
  91 struct anonymized_entry {
  92         struct hashmap_entry hash;
  93         const char *orig;
  94         size_t orig_len;
  95         const char *anon;
  96         size_t anon_len;
  97 };
  98
  99 static int anonymized_entry_cmp(const void *unused_cmp_data,
 100                                 const void *va, const void *vb,
 101                                 const void *unused_keydata)
 102 {
 103         const struct anonymized_entry *a = va, *b = vb;
 104         return a->orig_len != b->orig_len ||
 105                 memcmp(a->orig, b->orig, a->orig_len);
 106 }
 107
 108 /*
 109  * Basically keep a cache of X->Y so that we can repeatedly replace
 110  * the same anonymized string with another. The actual generation
 111  * is farmed out to the generate function.
 112  */
 113 static const void *anonymize_mem(struct hashmap *map,
 114                                  void *(*generate)(const void *, size_t *),
 115                                  const void *orig, size_t *len)
 116 {
 117         struct anonymized_entry key, *ret;
 118
 119         if (!map->cmpfn)
 120                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
 121
 122         hashmap_entry_init(&key, memhash(orig, *len));
 123         key.orig = orig;
 124         key.orig_len = *len;
 125         ret = hashmap_get(map, &key, NULL);
 126
 127         if (!ret) {
 128                 ret = xmalloc(sizeof(*ret));
 129                 hashmap_entry_init(&ret->hash, key.hash.hash);
 130                 ret->orig = xstrdup(orig);
 131                 ret->orig_len = *len;
 132                 ret->anon = generate(orig, len);
 133                 ret->anon_len = *len;
 134                 hashmap_put(map, ret);
 135         }
 136
 137         *len = ret->anon_len;
 138         return ret->anon;
 139 }
 140
 141 /*
 142  * We anonymize each component of a path individually,
 143  * so that paths a/b and a/c will share a common root.
 144  * The paths are cached via anonymize_mem so that repeated
 145  * lookups for "a" will yield the same value.
 146  */
 147 static void anonymize_path(struct strbuf *out, const char *path,
 148                            struct hashmap *map,
 149                            void *(*generate)(const void *, size_t *))
 150 {
 151         while (*path) {
 152                 const char *end_of_component = strchrnul(path, '/');
 153                 size_t len = end_of_component - path;
 154                 const char *c = anonymize_mem(map, generate, path, &len);
 155                 strbuf_add(out, c, len);
 156                 path = end_of_component;
 157                 if (*path)
 158                         strbuf_addch(out, *path++);
 159         }
 160 }
 161
 162 static inline void *mark_to_ptr(uint32_t mark)
 163 {
 164         return (void *)(uintptr_t)mark;
 165 }
 166
 167 static inline uint32_t ptr_to_mark(void * mark)
 168 {
 169         return (uint32_t)(uintptr_t)mark;
 170 }
 171
 172 static inline void mark_object(struct object *object, uint32_t mark)
 173 {
 174         add_decoration(&idnums, object, mark_to_ptr(mark));
 175 }
 176
 177 static inline void mark_next_object(struct object *object)
 178 {
 179         mark_object(object, ++last_idnum);
 180 }
 181
 182 static int get_object_mark(struct object *object)
 183 {
 184         void *decoration = lookup_decoration(&idnums, object);
 185         if (!decoration)
 186                 return 0;
 187         return ptr_to_mark(decoration);
 188 }
 189
 190 static void show_progress(void)
 191 {
 192         static int counter = 0;
 193         if (!progress)
 194                 return;
 195         if ((++counter % progress) == 0)
 196                 printf("progress %d objects\n", counter);
 197 }
 198
 199 /*
 200  * Ideally we would want some transformation of the blob data here
 201  * that is unreversible, but would still be the same size and have
 202  * the same data relationship to other blobs (so that we get the same
 203  * delta and packing behavior as the original). But the first and last
 204  * requirements there are probably mutually exclusive, so let's take
 205  * the easy way out for now, and just generate arbitrary content.
 206  *
 207  * There's no need to cache this result with anonymize_mem, since
 208  * we already handle blob content caching with marks.
 209  */
 210 static char *anonymize_blob(unsigned long *size)
 211 {
 212         static int counter;
 213         struct strbuf out = STRBUF_INIT;
 214         strbuf_addf(&out, "anonymous blob %d", counter++);
 215         *size = out.len;
 216         return strbuf_detach(&out, NULL);
 217 }
 218
 219 static void export_blob(const struct object_id *oid)
 220 {
 221         unsigned long size;
 222         enum object_type type;
 223         char *buf;
 224         struct object *object;
 225         int eaten;
 226
 227         if (no_data)
 228                 return;
 229
 230         if (is_null_oid(oid))
 231                 return;
 232
 233         object = lookup_object(the_repository, oid->hash);
 234         if (object && object->flags & SHOWN)
 235                 return;
 236
 237         if (anonymize) {
 238                 buf = anonymize_blob(&size);
 239                 object = (struct object *)lookup_blob(the_repository, oid);
 240                 eaten = 0;
 241         } else {
 242                 buf = read_object_file(oid, &type, &size);
 243                 if (!buf)
 244                         die ("Could not read blob %s", oid_to_hex(oid));
 245                 if (check_object_signature(oid, buf, size, type_name(type)) < 0)
 246                         die("sha1 mismatch in blob %s", oid_to_hex(oid));
 247                 object = parse_object_buffer(the_repository, oid, type,
 248                                              size, buf, &eaten);
 249         }
 250
 251         if (!object)
 252                 die("Could not read blob %s", oid_to_hex(oid));
 253
 254         mark_next_object(object);
 255
 256         printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
 257         if (size && fwrite(buf, size, 1, stdout) != 1)
 258                 die_errno ("Could not write blob '%s'", oid_to_hex(oid));
 259         printf("\n");
 260
 261         show_progress();
 262
 263         object->flags |= SHOWN;
 264         if (!eaten)
 265                 free(buf);
 266 }
 267
 268 static int depth_first(const void *a_, const void *b_)
 269 {
 270         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 271         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 272         const char *name_a, *name_b;
 273         int len_a, len_b, len;
 274         int cmp;
 275
 276         name_a = a->one ? a->one->path : a->two->path;
 277         name_b = b->one ? b->one->path : b->two->path;
 278
 279         len_a = strlen(name_a);
 280         len_b = strlen(name_b);
 281         len = (len_a < len_b) ? len_a : len_b;
 282
 283         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 284         cmp = memcmp(name_a, name_b, len);
 285         if (cmp)
 286                 return cmp;
 287         cmp = len_b - len_a;
 288         if (cmp)
 289                 return cmp;
 290         /*
 291          * Move 'R'ename entries last so that all references of the file
 292          * appear in the output before it is renamed (e.g., when a file
 293          * was copied and renamed in the same commit).
 294          */
 295         return (a->status == 'R') - (b->status == 'R');
 296 }
 297
 298 static void print_path_1(const char *path)
 299 {
 300         int need_quote = quote_c_style(path, NULL, NULL, 0);
 301         if (need_quote)
 302                 quote_c_style(path, NULL, stdout, 0);
 303         else if (strchr(path, ' '))
 304                 printf("\"%s\"", path);
 305         else
 306                 printf("%s", path);
 307 }
 308
 309 static void *anonymize_path_component(const void *path, size_t *len)
 310 {
 311         static int counter;
 312         struct strbuf out = STRBUF_INIT;
 313         strbuf_addf(&out, "path%d", counter++);
 314         return strbuf_detach(&out, len);
 315 }
 316
 317 static void print_path(const char *path)
 318 {
 319         if (!anonymize)
 320                 print_path_1(path);
 321         else {
 322                 static struct hashmap paths;
 323                 static struct strbuf anon = STRBUF_INIT;
 324
 325                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 326                 print_path_1(anon.buf);
 327                 strbuf_reset(&anon);
 328         }
 329 }
 330
 331 static void *generate_fake_oid(const void *old, size_t *len)
 332 {
 333         static uint32_t counter = 1; /* avoid null sha1 */
 334         unsigned char *out = xcalloc(GIT_SHA1_RAWSZ, 1);
 335         put_be32(out + GIT_SHA1_RAWSZ - 4, counter++);
 336         return out;
 337 }
 338
 339 static const unsigned char *anonymize_sha1(const struct object_id *oid)
 340 {
 341         static struct hashmap sha1s;
 342         size_t len = GIT_SHA1_RAWSZ;
 343         return anonymize_mem(&sha1s, generate_fake_oid, oid, &len);
 344 }
 345
 346 static void show_filemodify(struct diff_queue_struct *q,
 347                             struct diff_options *options, void *data)
 348 {
 349         int i;
 350         struct string_list *changed = data;
 351
 352         /*
 353          * Handle files below a directory first, in case they are all deleted
 354          * and the directory changes to a file or symlink.
 355          */
 356         QSORT(q->queue, q->nr, depth_first);
 357
 358         for (i = 0; i < q->nr; i++) {
 359                 struct diff_filespec *ospec = q->queue[i]->one;
 360                 struct diff_filespec *spec = q->queue[i]->two;
 361
 362                 switch (q->queue[i]->status) {
 363                 case DIFF_STATUS_DELETED:
 364                         printf("D ");
 365                         print_path(spec->path);
 366                         string_list_insert(changed, spec->path);
 367                         putchar('\n');
 368                         break;
 369
 370                 case DIFF_STATUS_COPIED:
 371                 case DIFF_STATUS_RENAMED:
 372                         /*
 373                          * If a change in the file corresponding to ospec->path
 374                          * has been observed, we cannot trust its contents
 375                          * because the diff is calculated based on the prior
 376                          * contents, not the current contents.  So, declare a
 377                          * copy or rename only if there was no change observed.
 378                          */
 379                         if (!string_list_has_string(changed, ospec->path)) {
 380                                 printf("%c ", q->queue[i]->status);
 381                                 print_path(ospec->path);
 382                                 putchar(' ');
 383                                 print_path(spec->path);
 384                                 string_list_insert(changed, spec->path);
 385                                 putchar('\n');
 386
 387                                 if (!oidcmp(&ospec->oid, &spec->oid) &&
 388                                     ospec->mode == spec->mode)
 389                                         break;
 390                         }
 391                         /* fallthrough */
 392
 393                 case DIFF_STATUS_TYPE_CHANGED:
 394                 case DIFF_STATUS_MODIFIED:
 395                 case DIFF_STATUS_ADDED:
 396                         /*
 397                          * Links refer to objects in another repositories;
 398                          * output the SHA-1 verbatim.
 399                          */
 400                         if (no_data || S_ISGITLINK(spec->mode))
 401                                 printf("M %06o %s ", spec->mode,
 402                                        sha1_to_hex(anonymize ?
 403                                                    anonymize_sha1(&spec->oid) :
 404                                                    spec->oid.hash));
 405                         else {
 406                                 struct object *object = lookup_object(the_repository,
 407                                                                       spec->oid.hash);
 408                                 printf("M %06o :%d ", spec->mode,
 409                                        get_object_mark(object));
 410                         }
 411                         print_path(spec->path);
 412                         string_list_insert(changed, spec->path);
 413                         putchar('\n');
 414                         break;
 415
 416                 default:
 417                         die("Unexpected comparison status '%c' for %s, %s",
 418                                 q->queue[i]->status,
 419                                 ospec->path ? ospec->path : "none",
 420                                 spec->path ? spec->path : "none");
 421                 }
 422         }
 423 }
 424
 425 static const char *find_encoding(const char *begin, const char *end)
 426 {
 427         const char *needle = "\nencoding ";
 428         char *bol, *eol;
 429
 430         bol = memmem(begin, end ? end - begin : strlen(begin),
 431                      needle, strlen(needle));
 432         if (!bol)
 433                 return git_commit_encoding;
 434         bol += strlen(needle);
 435         eol = strchrnul(bol, '\n');
 436         *eol = '\0';
 437         return bol;
 438 }
 439
 440 static void *anonymize_ref_component(const void *old, size_t *len)
 441 {
 442         static int counter;
 443         struct strbuf out = STRBUF_INIT;
 444         strbuf_addf(&out, "ref%d", counter++);
 445         return strbuf_detach(&out, len);
 446 }
 447
 448 static const char *anonymize_refname(const char *refname)
 449 {
 450         /*
 451          * If any of these prefixes is found, we will leave it intact
 452          * so that tags remain tags and so forth.
 453          */
 454         static const char *prefixes[] = {
 455                 "refs/heads/",
 456                 "refs/tags/",
 457                 "refs/remotes/",
 458                 "refs/"
 459         };
 460         static struct hashmap refs;
 461         static struct strbuf anon = STRBUF_INIT;
 462         int i;
 463
 464         /*
 465          * We also leave "master" as a special case, since it does not reveal
 466          * anything interesting.
 467          */
 468         if (!strcmp(refname, "refs/heads/master"))
 469                 return refname;
 470
 471         strbuf_reset(&anon);
 472         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 473                 if (skip_prefix(refname, prefixes[i], &refname)) {
 474                         strbuf_addstr(&anon, prefixes[i]);
 475                         break;
 476                 }
 477         }
 478
 479         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 480         return anon.buf;
 481 }
 482
 483 /*
 484  * We do not even bother to cache commit messages, as they are unlikely
 485  * to be repeated verbatim, and it is not that interesting when they are.
 486  */
 487 static char *anonymize_commit_message(const char *old)
 488 {
 489         static int counter;
 490         return xstrfmt("subject %d\n\nbody\n", counter++);
 491 }
 492
 493 static struct hashmap idents;
 494 static void *anonymize_ident(const void *old, size_t *len)
 495 {
 496         static int counter;
 497         struct strbuf out = STRBUF_INIT;
 498         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 499         counter++;
 500         return strbuf_detach(&out, len);
 501 }
 502
 503 /*
 504  * Our strategy here is to anonymize the names and email addresses,
 505  * but keep timestamps intact, as they influence things like traversal
 506  * order (and by themselves should not be too revealing).
 507  */
 508 static void anonymize_ident_line(const char **beg, const char **end)
 509 {
 510         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 511         static unsigned which_buffer;
 512
 513         struct strbuf *out;
 514         struct ident_split split;
 515         const char *end_of_header;
 516
 517         out = &buffers[which_buffer++];
 518         which_buffer %= ARRAY_SIZE(buffers);
 519         strbuf_reset(out);
 520
 521         /* skip "committer", "author", "tagger", etc */
 522         end_of_header = strchr(*beg, ' ');
 523         if (!end_of_header)
 524                 BUG("malformed line fed to anonymize_ident_line: %.*s",
 525                     (int)(*end - *beg), *beg);
 526         end_of_header++;
 527         strbuf_add(out, *beg, end_of_header - *beg);
 528
 529         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 530             split.date_begin) {
 531                 const char *ident;
 532                 size_t len;
 533
 534                 len = split.mail_end - split.name_begin;
 535                 ident = anonymize_mem(&idents, anonymize_ident,
 536                                       split.name_begin, &len);
 537                 strbuf_add(out, ident, len);
 538                 strbuf_addch(out, ' ');
 539                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 540         } else {
 541                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 542         }
 543
 544         *beg = out->buf;
 545         *end = out->buf + out->len;
 546 }
 547
 548 static void handle_commit(struct commit *commit, struct rev_info *rev,
 549                           struct string_list *paths_of_changed_objects)
 550 {
 551         int saved_output_format = rev->diffopt.output_format;
 552         const char *commit_buffer;
 553         const char *author, *author_end, *committer, *committer_end;
 554         const char *encoding, *message;
 555         char *reencoded = NULL;
 556         struct commit_list *p;
 557         const char *refname;
 558         int i;
 559
 560         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 561
 562         parse_commit_or_die(commit);
 563         commit_buffer = get_commit_buffer(commit, NULL);
 564         author = strstr(commit_buffer, "\nauthor ");
 565         if (!author)
 566                 die ("Could not find author in commit %s",
 567                      oid_to_hex(&commit->object.oid));
 568         author++;
 569         author_end = strchrnul(author, '\n');
 570         committer = strstr(author_end, "\ncommitter ");
 571         if (!committer)
 572                 die ("Could not find committer in commit %s",
 573                      oid_to_hex(&commit->object.oid));
 574         committer++;
 575         committer_end = strchrnul(committer, '\n');
 576         message = strstr(committer_end, "\n\n");
 577         encoding = find_encoding(committer_end, message);
 578         if (message)
 579                 message += 2;
 580
 581         if (commit->parents &&
 582             get_object_mark(&commit->parents->item->object) != 0 &&
 583             !full_tree) {
 584                 parse_commit_or_die(commit->parents->item);
 585                 diff_tree_oid(get_commit_tree_oid(commit->parents->item),
 586                               get_commit_tree_oid(commit), "", &rev->diffopt);
 587         }
 588         else
 589                 diff_root_tree_oid(get_commit_tree_oid(commit),
 590                                    "", &rev->diffopt);
 591
 592         /* Export the referenced blobs, and remember the marks. */
 593         for (i = 0; i < diff_queued_diff.nr; i++)
 594                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 595                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 596
 597         refname = *revision_sources_at(&revision_sources, commit);
 598         if (anonymize) {
 599                 refname = anonymize_refname(refname);
 600                 anonymize_ident_line(&committer, &committer_end);
 601                 anonymize_ident_line(&author, &author_end);
 602         }
 603
 604         mark_next_object(&commit->object);
 605         if (anonymize)
 606                 reencoded = anonymize_commit_message(message);
 607         else if (!is_encoding_utf8(encoding))
 608                 reencoded = reencode_string(message, "UTF-8", encoding);
 609         if (!commit->parents)
 610                 printf("reset %s\n", refname);
 611         printf("commit %s\nmark :%"PRIu32"\n%.*s\n%.*s\ndata %u\n%s",
 612                refname, last_idnum,
 613                (int)(author_end - author), author,
 614                (int)(committer_end - committer), committer,
 615                (unsigned)(reencoded
 616                           ? strlen(reencoded) : message
 617                           ? strlen(message) : 0),
 618                reencoded ? reencoded : message ? message : "");
 619         free(reencoded);
 620         unuse_commit_buffer(commit, commit_buffer);
 621
 622         for (i = 0, p = commit->parents; p; p = p->next) {
 623                 int mark = get_object_mark(&p->item->object);
 624                 if (!mark)
 625                         continue;
 626                 if (i == 0)
 627                         printf("from :%d\n", mark);
 628                 else
 629                         printf("merge :%d\n", mark);
 630                 i++;
 631         }
 632
 633         if (full_tree)
 634                 printf("deleteall\n");
 635         log_tree_diff_flush(rev);
 636         string_list_clear(paths_of_changed_objects, 0);
 637         rev->diffopt.output_format = saved_output_format;
 638
 639         printf("\n");
 640
 641         show_progress();
 642 }
 643
 644 static void *anonymize_tag(const void *old, size_t *len)
 645 {
 646         static int counter;
 647         struct strbuf out = STRBUF_INIT;
 648         strbuf_addf(&out, "tag message %d", counter++);
 649         return strbuf_detach(&out, len);
 650 }
 651
 652 static void handle_tail(struct object_array *commits, struct rev_info *revs,
 653                         struct string_list *paths_of_changed_objects)
 654 {
 655         struct commit *commit;
 656         while (commits->nr) {
 657                 commit = (struct commit *)object_array_pop(commits);
 658                 if (has_unshown_parent(commit)) {
 659                         /* Queue again, to be handled later */
 660                         add_object_array(&commit->object, NULL, commits);
 661                         return;
 662                 }
 663                 handle_commit(commit, revs, paths_of_changed_objects);
 664         }
 665 }
 666
 667 static void handle_tag(const char *name, struct tag *tag)
 668 {
 669         unsigned long size;
 670         enum object_type type;
 671         char *buf;
 672         const char *tagger, *tagger_end, *message;
 673         size_t message_size = 0;
 674         struct object *tagged;
 675         int tagged_mark;
 676         struct commit *p;
 677
 678         /* Trees have no identifier in fast-export output, thus we have no way
 679          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 680          * such tags.
 681          */
 682         tagged = tag->tagged;
 683         while (tagged->type == OBJ_TAG) {
 684                 tagged = ((struct tag *)tagged)->tagged;
 685         }
 686         if (tagged->type == OBJ_TREE) {
 687                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 688                         oid_to_hex(&tag->object.oid));
 689                 return;
 690         }
 691
 692         buf = read_object_file(&tag->object.oid, &type, &size);
 693         if (!buf)
 694                 die ("Could not read tag %s", oid_to_hex(&tag->object.oid));
 695         message = memmem(buf, size, "\n\n", 2);
 696         if (message) {
 697                 message += 2;
 698                 message_size = strlen(message);
 699         }
 700         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 701         if (!tagger) {
 702                 if (fake_missing_tagger)
 703                         tagger = "tagger Unspecified Tagger "
 704                                 "<unspecified-tagger> 0 +0000";
 705                 else
 706                         tagger = "";
 707                 tagger_end = tagger + strlen(tagger);
 708         } else {
 709                 tagger++;
 710                 tagger_end = strchrnul(tagger, '\n');
 711                 if (anonymize)
 712                         anonymize_ident_line(&tagger, &tagger_end);
 713         }
 714
 715         if (anonymize) {
 716                 name = anonymize_refname(name);
 717                 if (message) {
 718                         static struct hashmap tags;
 719                         message = anonymize_mem(&tags, anonymize_tag,
 720                                                 message, &message_size);
 721                 }
 722         }
 723
 724         /* handle signed tags */
 725         if (message) {
 726                 const char *signature = strstr(message,
 727                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 728                 if (signature)
 729                         switch(signed_tag_mode) {
 730                         case ABORT:
 731                                 die ("Encountered signed tag %s; use "
 732                                      "--signed-tags=<mode> to handle it.",
 733                                      oid_to_hex(&tag->object.oid));
 734                         case WARN:
 735                                 warning ("Exporting signed tag %s",
 736                                          oid_to_hex(&tag->object.oid));
 737                                 /* fallthru */
 738                         case VERBATIM:
 739                                 break;
 740                         case WARN_STRIP:
 741                                 warning ("Stripping signature from tag %s",
 742                                          oid_to_hex(&tag->object.oid));
 743                                 /* fallthru */
 744                         case STRIP:
 745                                 message_size = signature + 1 - message;
 746                                 break;
 747                         }
 748         }
 749
 750         /* handle tag->tagged having been filtered out due to paths specified */
 751         tagged = tag->tagged;
 752         tagged_mark = get_object_mark(tagged);
 753         if (!tagged_mark) {
 754                 switch(tag_of_filtered_mode) {
 755                 case ABORT:
 756                         die ("Tag %s tags unexported object; use "
 757                              "--tag-of-filtered-object=<mode> to handle it.",
 758                              oid_to_hex(&tag->object.oid));
 759                 case DROP:
 760                         /* Ignore this tag altogether */
 761                         free(buf);
 762                         return;
 763                 case REWRITE:
 764                         if (tagged->type != OBJ_COMMIT) {
 765                                 die ("Tag %s tags unexported %s!",
 766                                      oid_to_hex(&tag->object.oid),
 767                                      type_name(tagged->type));
 768                         }
 769                         p = (struct commit *)tagged;
 770                         for (;;) {
 771                                 if (p->parents && p->parents->next)
 772                                         break;
 773                                 if (p->object.flags & UNINTERESTING)
 774                                         break;
 775                                 if (!(p->object.flags & TREESAME))
 776                                         break;
 777                                 if (!p->parents)
 778                                         die ("Can't find replacement commit for tag %s\n",
 779                                              oid_to_hex(&tag->object.oid));
 780                                 p = p->parents->item;
 781                         }
 782                         tagged_mark = get_object_mark(&p->object);
 783                 }
 784         }
 785
 786         if (starts_with(name, "refs/tags/"))
 787                 name += 10;
 788         printf("tag %s\nfrom :%d\n%.*s%sdata %d\n%.*s\n",
 789                name, tagged_mark,
 790                (int)(tagger_end - tagger), tagger,
 791                tagger == tagger_end ? "" : "\n",
 792                (int)message_size, (int)message_size, message ? message : "");
 793         free(buf);
 794 }
 795
 796 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 797 {
 798         switch (e->item->type) {
 799         case OBJ_COMMIT:
 800                 return (struct commit *)e->item;
 801         case OBJ_TAG: {
 802                 struct tag *tag = (struct tag *)e->item;
 803
 804                 /* handle nested tags */
 805                 while (tag && tag->object.type == OBJ_TAG) {
 806                         parse_object(the_repository, &tag->object.oid);
 807                         string_list_append(&extra_refs, full_name)->util = tag;
 808                         tag = (struct tag *)tag->tagged;
 809                 }
 810                 if (!tag)
 811                         die("Tag %s points nowhere?", e->name);
 812                 return (struct commit *)tag;
 813                 break;
 814         }
 815         default:
 816                 return NULL;
 817         }
 818 }
 819
 820 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 821 {
 822         int i;
 823
 824         for (i = 0; i < info->nr; i++) {
 825                 struct rev_cmdline_entry *e = info->rev + i;
 826                 struct object_id oid;
 827                 struct commit *commit;
 828                 char *full_name;
 829
 830                 if (e->flags & UNINTERESTING)
 831                         continue;
 832
 833                 if (dwim_ref(e->name, strlen(e->name), &oid, &full_name) != 1)
 834                         continue;
 835
 836                 if (refspecs.nr) {
 837                         char *private;
 838                         private = apply_refspecs(&refspecs, full_name);
 839                         if (private) {
 840                                 free(full_name);
 841                                 full_name = private;
 842                         }
 843                 }
 844
 845                 commit = get_commit(e, full_name);
 846                 if (!commit) {
 847                         warning("%s: Unexpected object of type %s, skipping.",
 848                                 e->name,
 849                                 type_name(e->item->type));
 850                         continue;
 851                 }
 852
 853                 switch(commit->object.type) {
 854                 case OBJ_COMMIT:
 855                         break;
 856                 case OBJ_BLOB:
 857                         export_blob(&commit->object.oid);
 858                         continue;
 859                 default: /* OBJ_TAG (nested tags) is already handled */
 860                         warning("Tag points to object of unexpected type %s, skipping.",
 861                                 type_name(commit->object.type));
 862                         continue;
 863                 }
 864
 865                 /*
 866                  * This ref will not be updated through a commit, lets make
 867                  * sure it gets properly updated eventually.
 868                  */
 869                 if (*revision_sources_at(&revision_sources, commit) ||
 870                     commit->object.flags & SHOWN)
 871                         string_list_append(&extra_refs, full_name)->util = commit;
 872                 if (!*revision_sources_at(&revision_sources, commit))
 873                         *revision_sources_at(&revision_sources, commit) = full_name;
 874         }
 875 }
 876
 877 static void handle_tags_and_duplicates(void)
 878 {
 879         struct commit *commit;
 880         int i;
 881
 882         for (i = extra_refs.nr - 1; i >= 0; i--) {
 883                 const char *name = extra_refs.items[i].string;
 884                 struct object *object = extra_refs.items[i].util;
 885                 switch (object->type) {
 886                 case OBJ_TAG:
 887                         handle_tag(name, (struct tag *)object);
 888                         break;
 889                 case OBJ_COMMIT:
 890                         if (anonymize)
 891                                 name = anonymize_refname(name);
 892                         /* create refs pointing to already seen commits */
 893                         commit = (struct commit *)object;
 894                         printf("reset %s\nfrom :%d\n\n", name,
 895                                get_object_mark(&commit->object));
 896                         show_progress();
 897                         break;
 898                 }
 899         }
 900 }
 901
 902 static void export_marks(char *file)
 903 {
 904         unsigned int i;
 905         uint32_t mark;
 906         struct decoration_entry *deco = idnums.entries;
 907         FILE *f;
 908         int e = 0;
 909
 910         f = fopen_for_writing(file);
 911         if (!f)
 912                 die_errno("Unable to open marks file %s for writing.", file);
 913
 914         for (i = 0; i < idnums.size; i++) {
 915                 if (deco->base && deco->base->type == 1) {
 916                         mark = ptr_to_mark(deco->decoration);
 917                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
 918                                 oid_to_hex(&deco->base->oid)) < 0) {
 919                             e = 1;
 920                             break;
 921                         }
 922                 }
 923                 deco++;
 924         }
 925
 926         e |= ferror(f);
 927         e |= fclose(f);
 928         if (e)
 929                 error("Unable to write marks file %s.", file);
 930 }
 931
 932 static void import_marks(char *input_file)
 933 {
 934         char line[512];
 935         FILE *f = xfopen(input_file, "r");
 936
 937         while (fgets(line, sizeof(line), f)) {
 938                 uint32_t mark;
 939                 char *line_end, *mark_end;
 940                 struct object_id oid;
 941                 struct object *object;
 942                 struct commit *commit;
 943                 enum object_type type;
 944
 945                 line_end = strchr(line, '\n');
 946                 if (line[0] != ':' || !line_end)
 947                         die("corrupt mark line: %s", line);
 948                 *line_end = '\0';
 949
 950                 mark = strtoumax(line + 1, &mark_end, 10);
 951                 if (!mark || mark_end == line + 1
 952                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
 953                         die("corrupt mark line: %s", line);
 954
 955                 if (last_idnum < mark)
 956                         last_idnum = mark;
 957
 958                 type = oid_object_info(the_repository, &oid, NULL);
 959                 if (type < 0)
 960                         die("object not found: %s", oid_to_hex(&oid));
 961
 962                 if (type != OBJ_COMMIT)
 963                         /* only commits */
 964                         continue;
 965
 966                 commit = lookup_commit(the_repository, &oid);
 967                 if (!commit)
 968                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
 969
 970                 object = &commit->object;
 971
 972                 if (object->flags & SHOWN)
 973                         error("Object %s already has a mark", oid_to_hex(&oid));
 974
 975                 mark_object(object, mark);
 976
 977                 object->flags |= SHOWN;
 978         }
 979         fclose(f);
 980 }
 981
 982 static void handle_deletes(void)
 983 {
 984         int i;
 985         for (i = 0; i < refspecs.nr; i++) {
 986                 struct refspec_item *refspec = &refspecs.items[i];
 987                 if (*refspec->src)
 988                         continue;
 989
 990                 printf("reset %s\nfrom %s\n\n",
 991                                 refspec->dst, sha1_to_hex(null_sha1));
 992         }
 993 }
 994
 995 int cmd_fast_export(int argc, const char **argv, const char *prefix)
 996 {
 997         struct rev_info revs;
 998         struct object_array commits = OBJECT_ARRAY_INIT;
 999         struct commit *commit;
1000         char *export_filename = NULL, *import_filename = NULL;
1001         uint32_t lastimportid;
1002         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
1003         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
1004         struct option options[] = {
1005                 OPT_INTEGER(0, "progress", &progress,
1006                             N_("show progress after <n> objects")),
1007                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1008                              N_("select handling of signed tags"),
1009                              parse_opt_signed_tag_mode),
1010                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1011                              N_("select handling of tags that tag filtered objects"),
1012                              parse_opt_tag_of_filtered_mode),
1013                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1014                              N_("Dump marks to this file")),
1015                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1016                              N_("Import marks from this file")),
1017                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1018                          N_("Fake a tagger when tags lack one")),
1019                 OPT_BOOL(0, "full-tree", &full_tree,
1020                          N_("Output full tree for each commit")),
1021                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1022                              N_("Use the done feature to terminate the stream")),
1023                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1024                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1025                              N_("Apply refspec to exported refs")),
1026                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1027                 OPT_END()
1028         };
1029
1030         if (argc == 1)
1031                 usage_with_options (fast_export_usage, options);
1032
1033         /* we handle encodings */
1034         git_config(git_default_config, NULL);
1035
1036         init_revisions(&revs, prefix);
1037         init_revision_sources(&revision_sources);
1038         revs.topo_order = 1;
1039         revs.sources = &revision_sources;
1040         revs.rewrite_parents = 1;
1041         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1042                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1043         argc = setup_revisions(argc, argv, &revs, NULL);
1044         if (argc > 1)
1045                 usage_with_options (fast_export_usage, options);
1046
1047         if (refspecs_list.nr) {
1048                 int i;
1049
1050                 for (i = 0; i < refspecs_list.nr; i++)
1051                         refspec_append(&refspecs, refspecs_list.items[i].string);
1052
1053                 string_list_clear(&refspecs_list, 1);
1054         }
1055
1056         if (use_done_feature)
1057                 printf("feature done\n");
1058
1059         if (import_filename)
1060                 import_marks(import_filename);
1061         lastimportid = last_idnum;
1062
1063         if (import_filename && revs.prune_data.nr)
1064                 full_tree = 1;
1065
1066         get_tags_and_duplicates(&revs.cmdline);
1067
1068         if (prepare_revision_walk(&revs))
1069                 die("revision walk setup failed");
1070         revs.diffopt.format_callback = show_filemodify;
1071         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1072         revs.diffopt.flags.recursive = 1;
1073         while ((commit = get_revision(&revs))) {
1074                 if (has_unshown_parent(commit)) {
1075                         add_object_array(&commit->object, NULL, &commits);
1076                 }
1077                 else {
1078                         handle_commit(commit, &revs, &paths_of_changed_objects);
1079                         handle_tail(&commits, &revs, &paths_of_changed_objects);
1080                 }
1081         }
1082
1083         handle_tags_and_duplicates();
1084         handle_deletes();
1085
1086         if (export_filename && lastimportid != last_idnum)
1087                 export_marks(export_filename);
1088
1089         if (use_done_feature)
1090                 printf("done\n");
1091
1092         refspec_clear(&refspecs);
1093
1094         return 0;
1095 }