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 { SIGNED_TAG_ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = SIGNED_TAG_ABORT;
  35 static enum { TAG_FILTERING_ABORT, DROP, REWRITE } tag_of_filtered_mode = TAG_FILTERING_ABORT;
  36 static enum { REENCODE_ABORT, REENCODE_YES, REENCODE_NO } reencode_mode = REENCODE_ABORT;
  37 static int fake_missing_tagger;
  38 static int use_done_feature;
  39 static int no_data;
  40 static int full_tree;
  41 static int reference_excluded_commits;
  42 static int show_original_ids;
  43 static int mark_tags;
  44 static struct string_list extra_refs = STRING_LIST_INIT_NODUP;
  45 static struct string_list tag_refs = STRING_LIST_INIT_NODUP;
  46 static struct refspec refspecs = REFSPEC_INIT_FETCH;
  47 static int anonymize;
  48 static struct revision_sources revision_sources;
  49
  50 static int parse_opt_signed_tag_mode(const struct option *opt,
  51                                      const char *arg, int unset)
  52 {
  53         if (unset || !strcmp(arg, "abort"))
  54                 signed_tag_mode = SIGNED_TAG_ABORT;
  55         else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
  56                 signed_tag_mode = VERBATIM;
  57         else if (!strcmp(arg, "warn"))
  58                 signed_tag_mode = WARN;
  59         else if (!strcmp(arg, "warn-strip"))
  60                 signed_tag_mode = WARN_STRIP;
  61         else if (!strcmp(arg, "strip"))
  62                 signed_tag_mode = STRIP;
  63         else
  64                 return error("Unknown signed-tags mode: %s", arg);
  65         return 0;
  66 }
  67
  68 static int parse_opt_tag_of_filtered_mode(const struct option *opt,
  69                                           const char *arg, int unset)
  70 {
  71         if (unset || !strcmp(arg, "abort"))
  72                 tag_of_filtered_mode = TAG_FILTERING_ABORT;
  73         else if (!strcmp(arg, "drop"))
  74                 tag_of_filtered_mode = DROP;
  75         else if (!strcmp(arg, "rewrite"))
  76                 tag_of_filtered_mode = REWRITE;
  77         else
  78                 return error("Unknown tag-of-filtered mode: %s", arg);
  79         return 0;
  80 }
  81
  82 static int parse_opt_reencode_mode(const struct option *opt,
  83                                    const char *arg, int unset)
  84 {
  85         if (unset) {
  86                 reencode_mode = REENCODE_ABORT;
  87                 return 0;
  88         }
  89
  90         switch (git_parse_maybe_bool(arg)) {
  91         case 0:
  92                 reencode_mode = REENCODE_NO;
  93                 break;
  94         case 1:
  95                 reencode_mode = REENCODE_YES;
  96                 break;
  97         default:
  98                 if (!strcasecmp(arg, "abort"))
  99                         reencode_mode = REENCODE_ABORT;
 100                 else
 101                         return error("Unknown reencoding mode: %s", arg);
 102         }
 103
 104         return 0;
 105 }
 106
 107 static struct decoration idnums;
 108 static uint32_t last_idnum;
 109
 110 static int has_unshown_parent(struct commit *commit)
 111 {
 112         struct commit_list *parent;
 113
 114         for (parent = commit->parents; parent; parent = parent->next)
 115                 if (!(parent->item->object.flags & SHOWN) &&
 116                     !(parent->item->object.flags & UNINTERESTING))
 117                         return 1;
 118         return 0;
 119 }
 120
 121 struct anonymized_entry {
 122         struct hashmap_entry hash;
 123         const char *orig;
 124         size_t orig_len;
 125         const char *anon;
 126         size_t anon_len;
 127 };
 128
 129 static int anonymized_entry_cmp(const void *unused_cmp_data,
 130                                 const void *va, const void *vb,
 131                                 const void *unused_keydata)
 132 {
 133         const struct anonymized_entry *a = va, *b = vb;
 134         return a->orig_len != b->orig_len ||
 135                 memcmp(a->orig, b->orig, a->orig_len);
 136 }
 137
 138 /*
 139  * Basically keep a cache of X->Y so that we can repeatedly replace
 140  * the same anonymized string with another. The actual generation
 141  * is farmed out to the generate function.
 142  */
 143 static const void *anonymize_mem(struct hashmap *map,
 144                                  void *(*generate)(const void *, size_t *),
 145                                  const void *orig, size_t *len)
 146 {
 147         struct anonymized_entry key, *ret;
 148
 149         if (!map->cmpfn)
 150                 hashmap_init(map, anonymized_entry_cmp, NULL, 0);
 151
 152         hashmap_entry_init(&key, memhash(orig, *len));
 153         key.orig = orig;
 154         key.orig_len = *len;
 155         ret = hashmap_get(map, &key, NULL);
 156
 157         if (!ret) {
 158                 ret = xmalloc(sizeof(*ret));
 159                 hashmap_entry_init(&ret->hash, key.hash.hash);
 160                 ret->orig = xstrdup(orig);
 161                 ret->orig_len = *len;
 162                 ret->anon = generate(orig, len);
 163                 ret->anon_len = *len;
 164                 hashmap_put(map, ret);
 165         }
 166
 167         *len = ret->anon_len;
 168         return ret->anon;
 169 }
 170
 171 /*
 172  * We anonymize each component of a path individually,
 173  * so that paths a/b and a/c will share a common root.
 174  * The paths are cached via anonymize_mem so that repeated
 175  * lookups for "a" will yield the same value.
 176  */
 177 static void anonymize_path(struct strbuf *out, const char *path,
 178                            struct hashmap *map,
 179                            void *(*generate)(const void *, size_t *))
 180 {
 181         while (*path) {
 182                 const char *end_of_component = strchrnul(path, '/');
 183                 size_t len = end_of_component - path;
 184                 const char *c = anonymize_mem(map, generate, path, &len);
 185                 strbuf_add(out, c, len);
 186                 path = end_of_component;
 187                 if (*path)
 188                         strbuf_addch(out, *path++);
 189         }
 190 }
 191
 192 static inline void *mark_to_ptr(uint32_t mark)
 193 {
 194         return (void *)(uintptr_t)mark;
 195 }
 196
 197 static inline uint32_t ptr_to_mark(void * mark)
 198 {
 199         return (uint32_t)(uintptr_t)mark;
 200 }
 201
 202 static inline void mark_object(struct object *object, uint32_t mark)
 203 {
 204         add_decoration(&idnums, object, mark_to_ptr(mark));
 205 }
 206
 207 static inline void mark_next_object(struct object *object)
 208 {
 209         mark_object(object, ++last_idnum);
 210 }
 211
 212 static int get_object_mark(struct object *object)
 213 {
 214         void *decoration = lookup_decoration(&idnums, object);
 215         if (!decoration)
 216                 return 0;
 217         return ptr_to_mark(decoration);
 218 }
 219
 220 static struct commit *rewrite_commit(struct commit *p)
 221 {
 222         for (;;) {
 223                 if (p->parents && p->parents->next)
 224                         break;
 225                 if (p->object.flags & UNINTERESTING)
 226                         break;
 227                 if (!(p->object.flags & TREESAME))
 228                         break;
 229                 if (!p->parents)
 230                         return NULL;
 231                 p = p->parents->item;
 232         }
 233         return p;
 234 }
 235
 236 static void show_progress(void)
 237 {
 238         static int counter = 0;
 239         if (!progress)
 240                 return;
 241         if ((++counter % progress) == 0)
 242                 printf("progress %d objects\n", counter);
 243 }
 244
 245 /*
 246  * Ideally we would want some transformation of the blob data here
 247  * that is unreversible, but would still be the same size and have
 248  * the same data relationship to other blobs (so that we get the same
 249  * delta and packing behavior as the original). But the first and last
 250  * requirements there are probably mutually exclusive, so let's take
 251  * the easy way out for now, and just generate arbitrary content.
 252  *
 253  * There's no need to cache this result with anonymize_mem, since
 254  * we already handle blob content caching with marks.
 255  */
 256 static char *anonymize_blob(unsigned long *size)
 257 {
 258         static int counter;
 259         struct strbuf out = STRBUF_INIT;
 260         strbuf_addf(&out, "anonymous blob %d", counter++);
 261         *size = out.len;
 262         return strbuf_detach(&out, NULL);
 263 }
 264
 265 static void export_blob(const struct object_id *oid)
 266 {
 267         unsigned long size;
 268         enum object_type type;
 269         char *buf;
 270         struct object *object;
 271         int eaten;
 272
 273         if (no_data)
 274                 return;
 275
 276         if (is_null_oid(oid))
 277                 return;
 278
 279         object = lookup_object(the_repository, oid);
 280         if (object && object->flags & SHOWN)
 281                 return;
 282
 283         if (anonymize) {
 284                 buf = anonymize_blob(&size);
 285                 object = (struct object *)lookup_blob(the_repository, oid);
 286                 eaten = 0;
 287         } else {
 288                 buf = read_object_file(oid, &type, &size);
 289                 if (!buf)
 290                         die("could not read blob %s", oid_to_hex(oid));
 291                 if (check_object_signature(oid, buf, size, type_name(type)) < 0)
 292                         die("oid mismatch in blob %s", oid_to_hex(oid));
 293                 object = parse_object_buffer(the_repository, oid, type,
 294                                              size, buf, &eaten);
 295         }
 296
 297         if (!object)
 298                 die("Could not read blob %s", oid_to_hex(oid));
 299
 300         mark_next_object(object);
 301
 302         printf("blob\nmark :%"PRIu32"\n", last_idnum);
 303         if (show_original_ids)
 304                 printf("original-oid %s\n", oid_to_hex(oid));
 305         printf("data %"PRIuMAX"\n", (uintmax_t)size);
 306         if (size && fwrite(buf, size, 1, stdout) != 1)
 307                 die_errno("could not write blob '%s'", oid_to_hex(oid));
 308         printf("\n");
 309
 310         show_progress();
 311
 312         object->flags |= SHOWN;
 313         if (!eaten)
 314                 free(buf);
 315 }
 316
 317 static int depth_first(const void *a_, const void *b_)
 318 {
 319         const struct diff_filepair *a = *((const struct diff_filepair **)a_);
 320         const struct diff_filepair *b = *((const struct diff_filepair **)b_);
 321         const char *name_a, *name_b;
 322         int len_a, len_b, len;
 323         int cmp;
 324
 325         name_a = a->one ? a->one->path : a->two->path;
 326         name_b = b->one ? b->one->path : b->two->path;
 327
 328         len_a = strlen(name_a);
 329         len_b = strlen(name_b);
 330         len = (len_a < len_b) ? len_a : len_b;
 331
 332         /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
 333         cmp = memcmp(name_a, name_b, len);
 334         if (cmp)
 335                 return cmp;
 336         cmp = len_b - len_a;
 337         if (cmp)
 338                 return cmp;
 339         /*
 340          * Move 'R'ename entries last so that all references of the file
 341          * appear in the output before it is renamed (e.g., when a file
 342          * was copied and renamed in the same commit).
 343          */
 344         return (a->status == 'R') - (b->status == 'R');
 345 }
 346
 347 static void print_path_1(const char *path)
 348 {
 349         int need_quote = quote_c_style(path, NULL, NULL, 0);
 350         if (need_quote)
 351                 quote_c_style(path, NULL, stdout, 0);
 352         else if (strchr(path, ' '))
 353                 printf("\"%s\"", path);
 354         else
 355                 printf("%s", path);
 356 }
 357
 358 static void *anonymize_path_component(const void *path, size_t *len)
 359 {
 360         static int counter;
 361         struct strbuf out = STRBUF_INIT;
 362         strbuf_addf(&out, "path%d", counter++);
 363         return strbuf_detach(&out, len);
 364 }
 365
 366 static void print_path(const char *path)
 367 {
 368         if (!anonymize)
 369                 print_path_1(path);
 370         else {
 371                 static struct hashmap paths;
 372                 static struct strbuf anon = STRBUF_INIT;
 373
 374                 anonymize_path(&anon, path, &paths, anonymize_path_component);
 375                 print_path_1(anon.buf);
 376                 strbuf_reset(&anon);
 377         }
 378 }
 379
 380 static void *generate_fake_oid(const void *old, size_t *len)
 381 {
 382         static uint32_t counter = 1; /* avoid null oid */
 383         const unsigned hashsz = the_hash_algo->rawsz;
 384         unsigned char *out = xcalloc(hashsz, 1);
 385         put_be32(out + hashsz - 4, counter++);
 386         return out;
 387 }
 388
 389 static const struct object_id *anonymize_oid(const struct object_id *oid)
 390 {
 391         static struct hashmap objs;
 392         size_t len = the_hash_algo->rawsz;
 393         return anonymize_mem(&objs, generate_fake_oid, oid, &len);
 394 }
 395
 396 static void show_filemodify(struct diff_queue_struct *q,
 397                             struct diff_options *options, void *data)
 398 {
 399         int i;
 400         struct string_list *changed = data;
 401
 402         /*
 403          * Handle files below a directory first, in case they are all deleted
 404          * and the directory changes to a file or symlink.
 405          */
 406         QSORT(q->queue, q->nr, depth_first);
 407
 408         for (i = 0; i < q->nr; i++) {
 409                 struct diff_filespec *ospec = q->queue[i]->one;
 410                 struct diff_filespec *spec = q->queue[i]->two;
 411
 412                 switch (q->queue[i]->status) {
 413                 case DIFF_STATUS_DELETED:
 414                         printf("D ");
 415                         print_path(spec->path);
 416                         string_list_insert(changed, spec->path);
 417                         putchar('\n');
 418                         break;
 419
 420                 case DIFF_STATUS_COPIED:
 421                 case DIFF_STATUS_RENAMED:
 422                         /*
 423                          * If a change in the file corresponding to ospec->path
 424                          * has been observed, we cannot trust its contents
 425                          * because the diff is calculated based on the prior
 426                          * contents, not the current contents.  So, declare a
 427                          * copy or rename only if there was no change observed.
 428                          */
 429                         if (!string_list_has_string(changed, ospec->path)) {
 430                                 printf("%c ", q->queue[i]->status);
 431                                 print_path(ospec->path);
 432                                 putchar(' ');
 433                                 print_path(spec->path);
 434                                 string_list_insert(changed, spec->path);
 435                                 putchar('\n');
 436
 437                                 if (oideq(&ospec->oid, &spec->oid) &&
 438                                     ospec->mode == spec->mode)
 439                                         break;
 440                         }
 441                         /* fallthrough */
 442
 443                 case DIFF_STATUS_TYPE_CHANGED:
 444                 case DIFF_STATUS_MODIFIED:
 445                 case DIFF_STATUS_ADDED:
 446                         /*
 447                          * Links refer to objects in another repositories;
 448                          * output the SHA-1 verbatim.
 449                          */
 450                         if (no_data || S_ISGITLINK(spec->mode))
 451                                 printf("M %06o %s ", spec->mode,
 452                                        oid_to_hex(anonymize ?
 453                                                   anonymize_oid(&spec->oid) :
 454                                                   &spec->oid));
 455                         else {
 456                                 struct object *object = lookup_object(the_repository,
 457                                                                       &spec->oid);
 458                                 printf("M %06o :%d ", spec->mode,
 459                                        get_object_mark(object));
 460                         }
 461                         print_path(spec->path);
 462                         string_list_insert(changed, spec->path);
 463                         putchar('\n');
 464                         break;
 465
 466                 default:
 467                         die("Unexpected comparison status '%c' for %s, %s",
 468                                 q->queue[i]->status,
 469                                 ospec->path ? ospec->path : "none",
 470                                 spec->path ? spec->path : "none");
 471                 }
 472         }
 473 }
 474
 475 static const char *find_encoding(const char *begin, const char *end)
 476 {
 477         const char *needle = "\nencoding ";
 478         char *bol, *eol;
 479
 480         bol = memmem(begin, end ? end - begin : strlen(begin),
 481                      needle, strlen(needle));
 482         if (!bol)
 483                 return NULL;
 484         bol += strlen(needle);
 485         eol = strchrnul(bol, '\n');
 486         *eol = '\0';
 487         return bol;
 488 }
 489
 490 static void *anonymize_ref_component(const void *old, size_t *len)
 491 {
 492         static int counter;
 493         struct strbuf out = STRBUF_INIT;
 494         strbuf_addf(&out, "ref%d", counter++);
 495         return strbuf_detach(&out, len);
 496 }
 497
 498 static const char *anonymize_refname(const char *refname)
 499 {
 500         /*
 501          * If any of these prefixes is found, we will leave it intact
 502          * so that tags remain tags and so forth.
 503          */
 504         static const char *prefixes[] = {
 505                 "refs/heads/",
 506                 "refs/tags/",
 507                 "refs/remotes/",
 508                 "refs/"
 509         };
 510         static struct hashmap refs;
 511         static struct strbuf anon = STRBUF_INIT;
 512         int i;
 513
 514         /*
 515          * We also leave "master" as a special case, since it does not reveal
 516          * anything interesting.
 517          */
 518         if (!strcmp(refname, "refs/heads/master"))
 519                 return refname;
 520
 521         strbuf_reset(&anon);
 522         for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
 523                 if (skip_prefix(refname, prefixes[i], &refname)) {
 524                         strbuf_addstr(&anon, prefixes[i]);
 525                         break;
 526                 }
 527         }
 528
 529         anonymize_path(&anon, refname, &refs, anonymize_ref_component);
 530         return anon.buf;
 531 }
 532
 533 /*
 534  * We do not even bother to cache commit messages, as they are unlikely
 535  * to be repeated verbatim, and it is not that interesting when they are.
 536  */
 537 static char *anonymize_commit_message(const char *old)
 538 {
 539         static int counter;
 540         return xstrfmt("subject %d\n\nbody\n", counter++);
 541 }
 542
 543 static struct hashmap idents;
 544 static void *anonymize_ident(const void *old, size_t *len)
 545 {
 546         static int counter;
 547         struct strbuf out = STRBUF_INIT;
 548         strbuf_addf(&out, "User %d <user%d@example.com>", counter, counter);
 549         counter++;
 550         return strbuf_detach(&out, len);
 551 }
 552
 553 /*
 554  * Our strategy here is to anonymize the names and email addresses,
 555  * but keep timestamps intact, as they influence things like traversal
 556  * order (and by themselves should not be too revealing).
 557  */
 558 static void anonymize_ident_line(const char **beg, const char **end)
 559 {
 560         static struct strbuf buffers[] = { STRBUF_INIT, STRBUF_INIT };
 561         static unsigned which_buffer;
 562
 563         struct strbuf *out;
 564         struct ident_split split;
 565         const char *end_of_header;
 566
 567         out = &buffers[which_buffer++];
 568         which_buffer %= ARRAY_SIZE(buffers);
 569         strbuf_reset(out);
 570
 571         /* skip "committer", "author", "tagger", etc */
 572         end_of_header = strchr(*beg, ' ');
 573         if (!end_of_header)
 574                 BUG("malformed line fed to anonymize_ident_line: %.*s",
 575                     (int)(*end - *beg), *beg);
 576         end_of_header++;
 577         strbuf_add(out, *beg, end_of_header - *beg);
 578
 579         if (!split_ident_line(&split, end_of_header, *end - end_of_header) &&
 580             split.date_begin) {
 581                 const char *ident;
 582                 size_t len;
 583
 584                 len = split.mail_end - split.name_begin;
 585                 ident = anonymize_mem(&idents, anonymize_ident,
 586                                       split.name_begin, &len);
 587                 strbuf_add(out, ident, len);
 588                 strbuf_addch(out, ' ');
 589                 strbuf_add(out, split.date_begin, split.tz_end - split.date_begin);
 590         } else {
 591                 strbuf_addstr(out, "Malformed Ident <malformed@example.com> 0 -0000");
 592         }
 593
 594         *beg = out->buf;
 595         *end = out->buf + out->len;
 596 }
 597
 598 static void handle_commit(struct commit *commit, struct rev_info *rev,
 599                           struct string_list *paths_of_changed_objects)
 600 {
 601         int saved_output_format = rev->diffopt.output_format;
 602         const char *commit_buffer;
 603         const char *author, *author_end, *committer, *committer_end;
 604         const char *encoding, *message;
 605         char *reencoded = NULL;
 606         struct commit_list *p;
 607         const char *refname;
 608         int i;
 609
 610         rev->diffopt.output_format = DIFF_FORMAT_CALLBACK;
 611
 612         parse_commit_or_die(commit);
 613         commit_buffer = get_commit_buffer(commit, NULL);
 614         author = strstr(commit_buffer, "\nauthor ");
 615         if (!author)
 616                 die("could not find author in commit %s",
 617                     oid_to_hex(&commit->object.oid));
 618         author++;
 619         author_end = strchrnul(author, '\n');
 620         committer = strstr(author_end, "\ncommitter ");
 621         if (!committer)
 622                 die("could not find committer in commit %s",
 623                     oid_to_hex(&commit->object.oid));
 624         committer++;
 625         committer_end = strchrnul(committer, '\n');
 626         message = strstr(committer_end, "\n\n");
 627         encoding = find_encoding(committer_end, message);
 628         if (message)
 629                 message += 2;
 630
 631         if (commit->parents &&
 632             (get_object_mark(&commit->parents->item->object) != 0 ||
 633              reference_excluded_commits) &&
 634             !full_tree) {
 635                 parse_commit_or_die(commit->parents->item);
 636                 diff_tree_oid(get_commit_tree_oid(commit->parents->item),
 637                               get_commit_tree_oid(commit), "", &rev->diffopt);
 638         }
 639         else
 640                 diff_root_tree_oid(get_commit_tree_oid(commit),
 641                                    "", &rev->diffopt);
 642
 643         /* Export the referenced blobs, and remember the marks. */
 644         for (i = 0; i < diff_queued_diff.nr; i++)
 645                 if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
 646                         export_blob(&diff_queued_diff.queue[i]->two->oid);
 647
 648         refname = *revision_sources_at(&revision_sources, commit);
 649         /*
 650          * FIXME: string_list_remove() below for each ref is overall
 651          * O(N^2).  Compared to a history walk and diffing trees, this is
 652          * just lost in the noise in practice.  However, theoretically a
 653          * repo may have enough refs for this to become slow.
 654          */
 655         string_list_remove(&extra_refs, refname, 0);
 656         if (anonymize) {
 657                 refname = anonymize_refname(refname);
 658                 anonymize_ident_line(&committer, &committer_end);
 659                 anonymize_ident_line(&author, &author_end);
 660         }
 661
 662         mark_next_object(&commit->object);
 663         if (anonymize) {
 664                 reencoded = anonymize_commit_message(message);
 665         } else if (encoding) {
 666                 switch(reencode_mode) {
 667                 case REENCODE_YES:
 668                         reencoded = reencode_string(message, "UTF-8", encoding);
 669                         break;
 670                 case REENCODE_NO:
 671                         break;
 672                 case REENCODE_ABORT:
 673                         die("Encountered commit-specific encoding %s in commit "
 674                             "%s; use --reencode=[yes|no] to handle it",
 675                             encoding, oid_to_hex(&commit->object.oid));
 676                 }
 677         }
 678         if (!commit->parents)
 679                 printf("reset %s\n", refname);
 680         printf("commit %s\nmark :%"PRIu32"\n", refname, last_idnum);
 681         if (show_original_ids)
 682                 printf("original-oid %s\n", oid_to_hex(&commit->object.oid));
 683         printf("%.*s\n%.*s\n",
 684                (int)(author_end - author), author,
 685                (int)(committer_end - committer), committer);
 686         if (!reencoded && encoding)
 687                 printf("encoding %s\n", encoding);
 688         printf("data %u\n%s",
 689                (unsigned)(reencoded
 690                           ? strlen(reencoded) : message
 691                           ? strlen(message) : 0),
 692                reencoded ? reencoded : message ? message : "");
 693         free(reencoded);
 694         unuse_commit_buffer(commit, commit_buffer);
 695
 696         for (i = 0, p = commit->parents; p; p = p->next) {
 697                 struct object *obj = &p->item->object;
 698                 int mark = get_object_mark(obj);
 699
 700                 if (!mark && !reference_excluded_commits)
 701                         continue;
 702                 if (i == 0)
 703                         printf("from ");
 704                 else
 705                         printf("merge ");
 706                 if (mark)
 707                         printf(":%d\n", mark);
 708                 else
 709                         printf("%s\n", oid_to_hex(anonymize ?
 710                                                   anonymize_oid(&obj->oid) :
 711                                                   &obj->oid));
 712                 i++;
 713         }
 714
 715         if (full_tree)
 716                 printf("deleteall\n");
 717         log_tree_diff_flush(rev);
 718         string_list_clear(paths_of_changed_objects, 0);
 719         rev->diffopt.output_format = saved_output_format;
 720
 721         printf("\n");
 722
 723         show_progress();
 724 }
 725
 726 static void *anonymize_tag(const void *old, size_t *len)
 727 {
 728         static int counter;
 729         struct strbuf out = STRBUF_INIT;
 730         strbuf_addf(&out, "tag message %d", counter++);
 731         return strbuf_detach(&out, len);
 732 }
 733
 734 static void handle_tail(struct object_array *commits, struct rev_info *revs,
 735                         struct string_list *paths_of_changed_objects)
 736 {
 737         struct commit *commit;
 738         while (commits->nr) {
 739                 commit = (struct commit *)object_array_pop(commits);
 740                 if (has_unshown_parent(commit)) {
 741                         /* Queue again, to be handled later */
 742                         add_object_array(&commit->object, NULL, commits);
 743                         return;
 744                 }
 745                 handle_commit(commit, revs, paths_of_changed_objects);
 746         }
 747 }
 748
 749 static void handle_tag(const char *name, struct tag *tag)
 750 {
 751         unsigned long size;
 752         enum object_type type;
 753         char *buf;
 754         const char *tagger, *tagger_end, *message;
 755         size_t message_size = 0;
 756         struct object *tagged;
 757         int tagged_mark;
 758         struct commit *p;
 759
 760         /* Trees have no identifier in fast-export output, thus we have no way
 761          * to output tags of trees, tags of tags of trees, etc.  Simply omit
 762          * such tags.
 763          */
 764         tagged = tag->tagged;
 765         while (tagged->type == OBJ_TAG) {
 766                 tagged = ((struct tag *)tagged)->tagged;
 767         }
 768         if (tagged->type == OBJ_TREE) {
 769                 warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
 770                         oid_to_hex(&tag->object.oid));
 771                 return;
 772         }
 773
 774         buf = read_object_file(&tag->object.oid, &type, &size);
 775         if (!buf)
 776                 die("could not read tag %s", oid_to_hex(&tag->object.oid));
 777         message = memmem(buf, size, "\n\n", 2);
 778         if (message) {
 779                 message += 2;
 780                 message_size = strlen(message);
 781         }
 782         tagger = memmem(buf, message ? message - buf : size, "\ntagger ", 8);
 783         if (!tagger) {
 784                 if (fake_missing_tagger)
 785                         tagger = "tagger Unspecified Tagger "
 786                                 "<unspecified-tagger> 0 +0000";
 787                 else
 788                         tagger = "";
 789                 tagger_end = tagger + strlen(tagger);
 790         } else {
 791                 tagger++;
 792                 tagger_end = strchrnul(tagger, '\n');
 793                 if (anonymize)
 794                         anonymize_ident_line(&tagger, &tagger_end);
 795         }
 796
 797         if (anonymize) {
 798                 name = anonymize_refname(name);
 799                 if (message) {
 800                         static struct hashmap tags;
 801                         message = anonymize_mem(&tags, anonymize_tag,
 802                                                 message, &message_size);
 803                 }
 804         }
 805
 806         /* handle signed tags */
 807         if (message) {
 808                 const char *signature = strstr(message,
 809                                                "\n-----BEGIN PGP SIGNATURE-----\n");
 810                 if (signature)
 811                         switch(signed_tag_mode) {
 812                         case SIGNED_TAG_ABORT:
 813                                 die("encountered signed tag %s; use "
 814                                     "--signed-tags=<mode> to handle it",
 815                                     oid_to_hex(&tag->object.oid));
 816                         case WARN:
 817                                 warning("exporting signed tag %s",
 818                                         oid_to_hex(&tag->object.oid));
 819                                 /* fallthru */
 820                         case VERBATIM:
 821                                 break;
 822                         case WARN_STRIP:
 823                                 warning("stripping signature from tag %s",
 824                                         oid_to_hex(&tag->object.oid));
 825                                 /* fallthru */
 826                         case STRIP:
 827                                 message_size = signature + 1 - message;
 828                                 break;
 829                         }
 830         }
 831
 832         /* handle tag->tagged having been filtered out due to paths specified */
 833         tagged = tag->tagged;
 834         tagged_mark = get_object_mark(tagged);
 835         if (!tagged_mark) {
 836                 switch(tag_of_filtered_mode) {
 837                 case TAG_FILTERING_ABORT:
 838                         die("tag %s tags unexported object; use "
 839                             "--tag-of-filtered-object=<mode> to handle it",
 840                             oid_to_hex(&tag->object.oid));
 841                 case DROP:
 842                         /* Ignore this tag altogether */
 843                         free(buf);
 844                         return;
 845                 case REWRITE:
 846                         if (tagged->type != OBJ_COMMIT) {
 847                                 die("tag %s tags unexported %s!",
 848                                     oid_to_hex(&tag->object.oid),
 849                                     type_name(tagged->type));
 850                         }
 851                         p = rewrite_commit((struct commit *)tagged);
 852                         if (!p) {
 853                                 printf("reset %s\nfrom %s\n\n",
 854                                        name, oid_to_hex(&null_oid));
 855                                 free(buf);
 856                                 return;
 857                         }
 858                         tagged_mark = get_object_mark(&p->object);
 859                 }
 860         }
 861
 862         if (starts_with(name, "refs/tags/"))
 863                 name += 10;
 864         printf("tag %s\n", name);
 865         if (mark_tags) {
 866                 mark_next_object(&tag->object);
 867                 printf("mark :%"PRIu32"\n", last_idnum);
 868         }
 869         if (tagged_mark)
 870                 printf("from :%d\n", tagged_mark);
 871         else
 872                 printf("from %s\n", oid_to_hex(&tagged->oid));
 873
 874         if (show_original_ids)
 875                 printf("original-oid %s\n", oid_to_hex(&tag->object.oid));
 876         printf("%.*s%sdata %d\n%.*s\n",
 877                (int)(tagger_end - tagger), tagger,
 878                tagger == tagger_end ? "" : "\n",
 879                (int)message_size, (int)message_size, message ? message : "");
 880         free(buf);
 881 }
 882
 883 static struct commit *get_commit(struct rev_cmdline_entry *e, char *full_name)
 884 {
 885         switch (e->item->type) {
 886         case OBJ_COMMIT:
 887                 return (struct commit *)e->item;
 888         case OBJ_TAG: {
 889                 struct tag *tag = (struct tag *)e->item;
 890
 891                 /* handle nested tags */
 892                 while (tag && tag->object.type == OBJ_TAG) {
 893                         parse_object(the_repository, &tag->object.oid);
 894                         string_list_append(&tag_refs, full_name)->util = tag;
 895                         tag = (struct tag *)tag->tagged;
 896                 }
 897                 if (!tag)
 898                         die("Tag %s points nowhere?", e->name);
 899                 return (struct commit *)tag;
 900                 break;
 901         }
 902         default:
 903                 return NULL;
 904         }
 905 }
 906
 907 static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 908 {
 909         int i;
 910
 911         for (i = 0; i < info->nr; i++) {
 912                 struct rev_cmdline_entry *e = info->rev + i;
 913                 struct object_id oid;
 914                 struct commit *commit;
 915                 char *full_name;
 916
 917                 if (e->flags & UNINTERESTING)
 918                         continue;
 919
 920                 if (dwim_ref(e->name, strlen(e->name), &oid, &full_name) != 1)
 921                         continue;
 922
 923                 if (refspecs.nr) {
 924                         char *private;
 925                         private = apply_refspecs(&refspecs, full_name);
 926                         if (private) {
 927                                 free(full_name);
 928                                 full_name = private;
 929                         }
 930                 }
 931
 932                 commit = get_commit(e, full_name);
 933                 if (!commit) {
 934                         warning("%s: Unexpected object of type %s, skipping.",
 935                                 e->name,
 936                                 type_name(e->item->type));
 937                         continue;
 938                 }
 939
 940                 switch(commit->object.type) {
 941                 case OBJ_COMMIT:
 942                         break;
 943                 case OBJ_BLOB:
 944                         export_blob(&commit->object.oid);
 945                         continue;
 946                 default: /* OBJ_TAG (nested tags) is already handled */
 947                         warning("Tag points to object of unexpected type %s, skipping.",
 948                                 type_name(commit->object.type));
 949                         continue;
 950                 }
 951
 952                 /*
 953                  * Make sure this ref gets properly updated eventually, whether
 954                  * through a commit or manually at the end.
 955                  */
 956                 if (e->item->type != OBJ_TAG)
 957                         string_list_append(&extra_refs, full_name)->util = commit;
 958
 959                 if (!*revision_sources_at(&revision_sources, commit))
 960                         *revision_sources_at(&revision_sources, commit) = full_name;
 961         }
 962
 963         string_list_sort(&extra_refs);
 964         string_list_remove_duplicates(&extra_refs, 0);
 965 }
 966
 967 static void handle_tags_and_duplicates(struct string_list *extras)
 968 {
 969         struct commit *commit;
 970         int i;
 971
 972         for (i = extras->nr - 1; i >= 0; i--) {
 973                 const char *name = extras->items[i].string;
 974                 struct object *object = extras->items[i].util;
 975                 int mark;
 976
 977                 switch (object->type) {
 978                 case OBJ_TAG:
 979                         handle_tag(name, (struct tag *)object);
 980                         break;
 981                 case OBJ_COMMIT:
 982                         if (anonymize)
 983                                 name = anonymize_refname(name);
 984                         /* create refs pointing to already seen commits */
 985                         commit = rewrite_commit((struct commit *)object);
 986                         if (!commit) {
 987                                 /*
 988                                  * Neither this object nor any of its
 989                                  * ancestors touch any relevant paths, so
 990                                  * it has been filtered to nothing.  Delete
 991                                  * it.
 992                                  */
 993                                 printf("reset %s\nfrom %s\n\n",
 994                                        name, oid_to_hex(&null_oid));
 995                                 continue;
 996                         }
 997
 998                         mark = get_object_mark(&commit->object);
 999                         if (!mark) {
1000                                 /*
1001                                  * Getting here means we have a commit which
1002                                  * was excluded by a negative refspec (e.g.
1003                                  * fast-export ^master master).  If we are
1004                                  * referencing excluded commits, set the ref
1005                                  * to the exact commit.  Otherwise, the user
1006                                  * wants the branch exported but every commit
1007                                  * in its history to be deleted, which basically
1008                                  * just means deletion of the ref.
1009                                  */
1010                                 if (!reference_excluded_commits) {
1011                                         /* delete the ref */
1012                                         printf("reset %s\nfrom %s\n\n",
1013                                                name, oid_to_hex(&null_oid));
1014                                         continue;
1015                                 }
1016                                 /* set ref to commit using oid, not mark */
1017                                 printf("reset %s\nfrom %s\n\n", name,
1018                                        oid_to_hex(&commit->object.oid));
1019                                 continue;
1020                         }
1021
1022                         printf("reset %s\nfrom :%d\n\n", name, mark
1023                                );
1024                         show_progress();
1025                         break;
1026                 }
1027         }
1028 }
1029
1030 static void export_marks(char *file)
1031 {
1032         unsigned int i;
1033         uint32_t mark;
1034         struct decoration_entry *deco = idnums.entries;
1035         FILE *f;
1036         int e = 0;
1037
1038         f = fopen_for_writing(file);
1039         if (!f)
1040                 die_errno("Unable to open marks file %s for writing.", file);
1041
1042         for (i = 0; i < idnums.size; i++) {
1043                 if (deco->base && deco->base->type == 1) {
1044                         mark = ptr_to_mark(deco->decoration);
1045                         if (fprintf(f, ":%"PRIu32" %s\n", mark,
1046                                 oid_to_hex(&deco->base->oid)) < 0) {
1047                             e = 1;
1048                             break;
1049                         }
1050                 }
1051                 deco++;
1052         }
1053
1054         e |= ferror(f);
1055         e |= fclose(f);
1056         if (e)
1057                 error("Unable to write marks file %s.", file);
1058 }
1059
1060 static void import_marks(char *input_file, int check_exists)
1061 {
1062         char line[512];
1063         FILE *f;
1064         struct stat sb;
1065
1066         if (check_exists && stat(input_file, &sb))
1067                 return;
1068
1069         f = xfopen(input_file, "r");
1070         while (fgets(line, sizeof(line), f)) {
1071                 uint32_t mark;
1072                 char *line_end, *mark_end;
1073                 struct object_id oid;
1074                 struct object *object;
1075                 struct commit *commit;
1076                 enum object_type type;
1077
1078                 line_end = strchr(line, '\n');
1079                 if (line[0] != ':' || !line_end)
1080                         die("corrupt mark line: %s", line);
1081                 *line_end = '\0';
1082
1083                 mark = strtoumax(line + 1, &mark_end, 10);
1084                 if (!mark || mark_end == line + 1
1085                         || *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
1086                         die("corrupt mark line: %s", line);
1087
1088                 if (last_idnum < mark)
1089                         last_idnum = mark;
1090
1091                 type = oid_object_info(the_repository, &oid, NULL);
1092                 if (type < 0)
1093                         die("object not found: %s", oid_to_hex(&oid));
1094
1095                 if (type != OBJ_COMMIT)
1096                         /* only commits */
1097                         continue;
1098
1099                 commit = lookup_commit(the_repository, &oid);
1100                 if (!commit)
1101                         die("not a commit? can't happen: %s", oid_to_hex(&oid));
1102
1103                 object = &commit->object;
1104
1105                 if (object->flags & SHOWN)
1106                         error("Object %s already has a mark", oid_to_hex(&oid));
1107
1108                 mark_object(object, mark);
1109
1110                 object->flags |= SHOWN;
1111         }
1112         fclose(f);
1113 }
1114
1115 static void handle_deletes(void)
1116 {
1117         int i;
1118         for (i = 0; i < refspecs.nr; i++) {
1119                 struct refspec_item *refspec = &refspecs.items[i];
1120                 if (*refspec->src)
1121                         continue;
1122
1123                 printf("reset %s\nfrom %s\n\n",
1124                                 refspec->dst, oid_to_hex(&null_oid));
1125         }
1126 }
1127
1128 int cmd_fast_export(int argc, const char **argv, const char *prefix)
1129 {
1130         struct rev_info revs;
1131         struct object_array commits = OBJECT_ARRAY_INIT;
1132         struct commit *commit;
1133         char *export_filename = NULL,
1134              *import_filename = NULL,
1135              *import_filename_if_exists = NULL;
1136         uint32_t lastimportid;
1137         struct string_list refspecs_list = STRING_LIST_INIT_NODUP;
1138         struct string_list paths_of_changed_objects = STRING_LIST_INIT_DUP;
1139         struct option options[] = {
1140                 OPT_INTEGER(0, "progress", &progress,
1141                             N_("show progress after <n> objects")),
1142                 OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
1143                              N_("select handling of signed tags"),
1144                              parse_opt_signed_tag_mode),
1145                 OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
1146                              N_("select handling of tags that tag filtered objects"),
1147                              parse_opt_tag_of_filtered_mode),
1148                 OPT_CALLBACK(0, "reencode", &reencode_mode, N_("mode"),
1149                              N_("select handling of commit messages in an alternate encoding"),
1150                              parse_opt_reencode_mode),
1151                 OPT_STRING(0, "export-marks", &export_filename, N_("file"),
1152                              N_("Dump marks to this file")),
1153                 OPT_STRING(0, "import-marks", &import_filename, N_("file"),
1154                              N_("Import marks from this file")),
1155                 OPT_STRING(0, "import-marks-if-exists",
1156                              &import_filename_if_exists,
1157                              N_("file"),
1158                              N_("Import marks from this file if it exists")),
1159                 OPT_BOOL(0, "fake-missing-tagger", &fake_missing_tagger,
1160                          N_("Fake a tagger when tags lack one")),
1161                 OPT_BOOL(0, "full-tree", &full_tree,
1162                          N_("Output full tree for each commit")),
1163                 OPT_BOOL(0, "use-done-feature", &use_done_feature,
1164                              N_("Use the done feature to terminate the stream")),
1165                 OPT_BOOL(0, "no-data", &no_data, N_("Skip output of blob data")),
1166                 OPT_STRING_LIST(0, "refspec", &refspecs_list, N_("refspec"),
1167                              N_("Apply refspec to exported refs")),
1168                 OPT_BOOL(0, "anonymize", &anonymize, N_("anonymize output")),
1169                 OPT_BOOL(0, "reference-excluded-parents",
1170                          &reference_excluded_commits, N_("Reference parents which are not in fast-export stream by object id")),
1171                 OPT_BOOL(0, "show-original-ids", &show_original_ids,
1172                             N_("Show original object ids of blobs/commits")),
1173                 OPT_BOOL(0, "mark-tags", &mark_tags,
1174                             N_("Label tags with mark ids")),
1175
1176                 OPT_END()
1177         };
1178
1179         if (argc == 1)
1180                 usage_with_options (fast_export_usage, options);
1181
1182         /* we handle encodings */
1183         git_config(git_default_config, NULL);
1184
1185         repo_init_revisions(the_repository, &revs, prefix);
1186         init_revision_sources(&revision_sources);
1187         revs.topo_order = 1;
1188         revs.sources = &revision_sources;
1189         revs.rewrite_parents = 1;
1190         argc = parse_options(argc, argv, prefix, options, fast_export_usage,
1191                         PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN);
1192         argc = setup_revisions(argc, argv, &revs, NULL);
1193         if (argc > 1)
1194                 usage_with_options (fast_export_usage, options);
1195
1196         if (refspecs_list.nr) {
1197                 int i;
1198
1199                 for (i = 0; i < refspecs_list.nr; i++)
1200                         refspec_append(&refspecs, refspecs_list.items[i].string);
1201
1202                 string_list_clear(&refspecs_list, 1);
1203         }
1204
1205         if (use_done_feature)
1206                 printf("feature done\n");
1207
1208         if (import_filename && import_filename_if_exists)
1209                 die(_("Cannot pass both --import-marks and --import-marks-if-exists"));
1210         if (import_filename)
1211                 import_marks(import_filename, 0);
1212         else if (import_filename_if_exists)
1213                 import_marks(import_filename_if_exists, 1);
1214         lastimportid = last_idnum;
1215
1216         if (import_filename && revs.prune_data.nr)
1217                 full_tree = 1;
1218
1219         get_tags_and_duplicates(&revs.cmdline);
1220
1221         if (prepare_revision_walk(&revs))
1222                 die("revision walk setup failed");
1223         revs.diffopt.format_callback = show_filemodify;
1224         revs.diffopt.format_callback_data = &paths_of_changed_objects;
1225         revs.diffopt.flags.recursive = 1;
1226         while ((commit = get_revision(&revs))) {
1227                 if (has_unshown_parent(commit)) {
1228                         add_object_array(&commit->object, NULL, &commits);
1229                 }
1230                 else {
1231                         handle_commit(commit, &revs, &paths_of_changed_objects);
1232                         handle_tail(&commits, &revs, &paths_of_changed_objects);
1233                 }
1234         }
1235
1236         handle_tags_and_duplicates(&extra_refs);
1237         handle_tags_and_duplicates(&tag_refs);
1238         handle_deletes();
1239
1240         if (export_filename && lastimportid != last_idnum)
1241                 export_marks(export_filename);
1242
1243         if (use_done_feature)
1244                 printf("done\n");
1245
1246         refspec_clear(&refspecs);
1247
1248         return 0;
1249 }