builtin/name-rev.c

   1 #include "builtin.h"
   2 #include "alloc.h"
   3 #include "environment.h"
   4 #include "gettext.h"
   5 #include "hex.h"
   6 #include "repository.h"
   7 #include "config.h"
   8 #include "commit.h"
   9 #include "tag.h"
  10 #include "refs.h"
  11 #include "object-name.h"
  12 #include "parse-options.h"
  13 #include "prio-queue.h"
  14 #include "hash-lookup.h"
  15 #include "commit-slab.h"
  16 #include "commit-graph.h"
  17
  18 /*
  19  * One day.  See the 'name a rev shortly after epoch' test in t6120 when
  20  * changing this value
  21  */
  22 #define CUTOFF_DATE_SLOP 86400
  23
  24 struct rev_name {
  25         const char *tip_name;
  26         timestamp_t taggerdate;
  27         int generation;
  28         int distance;
  29         int from_tag;
  30 };
  31
  32 define_commit_slab(commit_rev_name, struct rev_name);
  33
  34 static timestamp_t generation_cutoff = GENERATION_NUMBER_INFINITY;
  35 static timestamp_t cutoff = TIME_MAX;
  36 static struct commit_rev_name rev_names;
  37
  38 /* Disable the cutoff checks entirely */
  39 static void disable_cutoff(void)
  40 {
  41         generation_cutoff = 0;
  42         cutoff = 0;
  43 }
  44
  45 /* Cutoff searching any commits older than this one */
  46 static void set_commit_cutoff(struct commit *commit)
  47 {
  48
  49         if (cutoff > commit->date)
  50                 cutoff = commit->date;
  51
  52         if (generation_cutoff) {
  53                 timestamp_t generation = commit_graph_generation(commit);
  54
  55                 if (generation_cutoff > generation)
  56                         generation_cutoff = generation;
  57         }
  58 }
  59
  60 /* adjust the commit date cutoff with a slop to allow for slightly incorrect
  61  * commit timestamps in case of clock skew.
  62  */
  63 static void adjust_cutoff_timestamp_for_slop(void)
  64 {
  65         if (cutoff) {
  66                 /* check for undeflow */
  67                 if (cutoff > TIME_MIN + CUTOFF_DATE_SLOP)
  68                         cutoff = cutoff - CUTOFF_DATE_SLOP;
  69                 else
  70                         cutoff = TIME_MIN;
  71         }
  72 }
  73
  74 /* Check if a commit is before the cutoff. Prioritize generation numbers
  75  * first, but use the commit timestamp if we lack generation data.
  76  */
  77 static int commit_is_before_cutoff(struct commit *commit)
  78 {
  79         if (generation_cutoff < GENERATION_NUMBER_INFINITY)
  80                 return generation_cutoff &&
  81                         commit_graph_generation(commit) < generation_cutoff;
  82
  83         return commit->date < cutoff;
  84 }
  85
  86 /* How many generations are maximally preferred over _one_ merge traversal? */
  87 #define MERGE_TRAVERSAL_WEIGHT 65535
  88
  89 static int is_valid_rev_name(const struct rev_name *name)
  90 {
  91         return name && name->tip_name;
  92 }
  93
  94 static struct rev_name *get_commit_rev_name(const struct commit *commit)
  95 {
  96         struct rev_name *name = commit_rev_name_peek(&rev_names, commit);
  97
  98         return is_valid_rev_name(name) ? name : NULL;
  99 }
 100
 101 static int effective_distance(int distance, int generation)
 102 {
 103         return distance + (generation > 0 ? MERGE_TRAVERSAL_WEIGHT : 0);
 104 }
 105
 106 static int is_better_name(struct rev_name *name,
 107                           timestamp_t taggerdate,
 108                           int generation,
 109                           int distance,
 110                           int from_tag)
 111 {
 112         int name_distance = effective_distance(name->distance, name->generation);
 113         int new_distance = effective_distance(distance, generation);
 114
 115         /* If both are tags, we prefer the nearer one. */
 116         if (from_tag && name->from_tag)
 117                 return name_distance > new_distance;
 118
 119         /* Favor a tag over a non-tag. */
 120         if (name->from_tag != from_tag)
 121                 return from_tag;
 122
 123         /*
 124          * We are now looking at two non-tags.  Tiebreak to favor
 125          * shorter hops.
 126          */
 127         if (name_distance != new_distance)
 128                 return name_distance > new_distance;
 129
 130         /* ... or tiebreak to favor older date */
 131         if (name->taggerdate != taggerdate)
 132                 return name->taggerdate > taggerdate;
 133
 134         /* keep the current one if we cannot decide */
 135         return 0;
 136 }
 137
 138 static struct rev_name *create_or_update_name(struct commit *commit,
 139                                               timestamp_t taggerdate,
 140                                               int generation, int distance,
 141                                               int from_tag)
 142 {
 143         struct rev_name *name = commit_rev_name_at(&rev_names, commit);
 144
 145         if (is_valid_rev_name(name) &&
 146             !is_better_name(name, taggerdate, generation, distance, from_tag))
 147                 return NULL;
 148
 149         name->taggerdate = taggerdate;
 150         name->generation = generation;
 151         name->distance = distance;
 152         name->from_tag = from_tag;
 153
 154         return name;
 155 }
 156
 157 static char *get_parent_name(const struct rev_name *name, int parent_number)
 158 {
 159         struct strbuf sb = STRBUF_INIT;
 160         size_t len;
 161
 162         strip_suffix(name->tip_name, "^0", &len);
 163         if (name->generation > 0) {
 164                 strbuf_grow(&sb, len +
 165                             1 + decimal_width(name->generation) +
 166                             1 + decimal_width(parent_number));
 167                 strbuf_addf(&sb, "%.*s~%d^%d", (int)len, name->tip_name,
 168                             name->generation, parent_number);
 169         } else {
 170                 strbuf_grow(&sb, len +
 171                             1 + decimal_width(parent_number));
 172                 strbuf_addf(&sb, "%.*s^%d", (int)len, name->tip_name,
 173                             parent_number);
 174         }
 175         return strbuf_detach(&sb, NULL);
 176 }
 177
 178 static void name_rev(struct commit *start_commit,
 179                 const char *tip_name, timestamp_t taggerdate,
 180                 int from_tag, int deref)
 181 {
 182         struct prio_queue queue;
 183         struct commit *commit;
 184         struct commit **parents_to_queue = NULL;
 185         size_t parents_to_queue_nr, parents_to_queue_alloc = 0;
 186         struct rev_name *start_name;
 187
 188         repo_parse_commit(the_repository, start_commit);
 189         if (commit_is_before_cutoff(start_commit))
 190                 return;
 191
 192         start_name = create_or_update_name(start_commit, taggerdate, 0, 0,
 193                                            from_tag);
 194         if (!start_name)
 195                 return;
 196         if (deref)
 197                 start_name->tip_name = xstrfmt("%s^0", tip_name);
 198         else
 199                 start_name->tip_name = xstrdup(tip_name);
 200
 201         memset(&queue, 0, sizeof(queue)); /* Use the prio_queue as LIFO */
 202         prio_queue_put(&queue, start_commit);
 203
 204         while ((commit = prio_queue_get(&queue))) {
 205                 struct rev_name *name = get_commit_rev_name(commit);
 206                 struct commit_list *parents;
 207                 int parent_number = 1;
 208
 209                 parents_to_queue_nr = 0;
 210
 211                 for (parents = commit->parents;
 212                                 parents;
 213                                 parents = parents->next, parent_number++) {
 214                         struct commit *parent = parents->item;
 215                         struct rev_name *parent_name;
 216                         int generation, distance;
 217
 218                         repo_parse_commit(the_repository, parent);
 219                         if (commit_is_before_cutoff(parent))
 220                                 continue;
 221
 222                         if (parent_number > 1) {
 223                                 generation = 0;
 224                                 distance = name->distance + MERGE_TRAVERSAL_WEIGHT;
 225                         } else {
 226                                 generation = name->generation + 1;
 227                                 distance = name->distance + 1;
 228                         }
 229
 230                         parent_name = create_or_update_name(parent, taggerdate,
 231                                                             generation,
 232                                                             distance, from_tag);
 233                         if (parent_name) {
 234                                 if (parent_number > 1)
 235                                         parent_name->tip_name =
 236                                                 get_parent_name(name,
 237                                                                 parent_number);
 238                                 else
 239                                         parent_name->tip_name = name->tip_name;
 240                                 ALLOC_GROW(parents_to_queue,
 241                                            parents_to_queue_nr + 1,
 242                                            parents_to_queue_alloc);
 243                                 parents_to_queue[parents_to_queue_nr] = parent;
 244                                 parents_to_queue_nr++;
 245                         }
 246                 }
 247
 248                 /* The first parent must come out first from the prio_queue */
 249                 while (parents_to_queue_nr)
 250                         prio_queue_put(&queue,
 251                                        parents_to_queue[--parents_to_queue_nr]);
 252         }
 253
 254         clear_prio_queue(&queue);
 255         free(parents_to_queue);
 256 }
 257
 258 static int subpath_matches(const char *path, const char *filter)
 259 {
 260         const char *subpath = path;
 261
 262         while (subpath) {
 263                 if (!wildmatch(filter, subpath, 0))
 264                         return subpath - path;
 265                 subpath = strchr(subpath, '/');
 266                 if (subpath)
 267                         subpath++;
 268         }
 269         return -1;
 270 }
 271
 272 struct name_ref_data {
 273         int tags_only;
 274         int name_only;
 275         struct string_list ref_filters;
 276         struct string_list exclude_filters;
 277 };
 278
 279 static struct tip_table {
 280         struct tip_table_entry {
 281                 struct object_id oid;
 282                 const char *refname;
 283                 struct commit *commit;
 284                 timestamp_t taggerdate;
 285                 unsigned int from_tag:1;
 286                 unsigned int deref:1;
 287         } *table;
 288         int nr;
 289         int alloc;
 290         int sorted;
 291 } tip_table;
 292
 293 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 294                              int shorten_unambiguous, struct commit *commit,
 295                              timestamp_t taggerdate, int from_tag, int deref)
 296 {
 297         char *short_refname = NULL;
 298
 299         if (shorten_unambiguous)
 300                 short_refname = shorten_unambiguous_ref(refname, 0);
 301         else if (skip_prefix(refname, "refs/heads/", &refname))
 302                 ; /* refname already advanced */
 303         else
 304                 skip_prefix(refname, "refs/", &refname);
 305
 306         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 307         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 308         tip_table.table[tip_table.nr].refname = short_refname ?
 309                 short_refname : xstrdup(refname);
 310         tip_table.table[tip_table.nr].commit = commit;
 311         tip_table.table[tip_table.nr].taggerdate = taggerdate;
 312         tip_table.table[tip_table.nr].from_tag = from_tag;
 313         tip_table.table[tip_table.nr].deref = deref;
 314         tip_table.nr++;
 315         tip_table.sorted = 0;
 316 }
 317
 318 static int tipcmp(const void *a_, const void *b_)
 319 {
 320         const struct tip_table_entry *a = a_, *b = b_;
 321         return oidcmp(&a->oid, &b->oid);
 322 }
 323
 324 static int cmp_by_tag_and_age(const void *a_, const void *b_)
 325 {
 326         const struct tip_table_entry *a = a_, *b = b_;
 327         int cmp;
 328
 329         /* Prefer tags. */
 330         cmp = b->from_tag - a->from_tag;
 331         if (cmp)
 332                 return cmp;
 333
 334         /* Older is better. */
 335         if (a->taggerdate < b->taggerdate)
 336                 return -1;
 337         return a->taggerdate != b->taggerdate;
 338 }
 339
 340 static int name_ref(const char *path, const struct object_id *oid,
 341                     int flags UNUSED, void *cb_data)
 342 {
 343         struct object *o = parse_object(the_repository, oid);
 344         struct name_ref_data *data = cb_data;
 345         int can_abbreviate_output = data->tags_only && data->name_only;
 346         int deref = 0;
 347         int from_tag = 0;
 348         struct commit *commit = NULL;
 349         timestamp_t taggerdate = TIME_MAX;
 350
 351         if (data->tags_only && !starts_with(path, "refs/tags/"))
 352                 return 0;
 353
 354         if (data->exclude_filters.nr) {
 355                 struct string_list_item *item;
 356
 357                 for_each_string_list_item(item, &data->exclude_filters) {
 358                         if (subpath_matches(path, item->string) >= 0)
 359                                 return 0;
 360                 }
 361         }
 362
 363         if (data->ref_filters.nr) {
 364                 struct string_list_item *item;
 365                 int matched = 0;
 366
 367                 /* See if any of the patterns match. */
 368                 for_each_string_list_item(item, &data->ref_filters) {
 369                         /*
 370                          * Check all patterns even after finding a match, so
 371                          * that we can see if a match with a subpath exists.
 372                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 373                          * both of which match, the user is showing her
 374                          * willingness to accept a shortened output by having
 375                          * the 'v1.*' in the acceptable refnames, so we
 376                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 377                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 378                          */
 379                         switch (subpath_matches(path, item->string)) {
 380                         case -1: /* did not match */
 381                                 break;
 382                         case 0: /* matched fully */
 383                                 matched = 1;
 384                                 break;
 385                         default: /* matched subpath */
 386                                 matched = 1;
 387                                 can_abbreviate_output = 1;
 388                                 break;
 389                         }
 390                 }
 391
 392                 /* If none of the patterns matched, stop now */
 393                 if (!matched)
 394                         return 0;
 395         }
 396
 397         while (o && o->type == OBJ_TAG) {
 398                 struct tag *t = (struct tag *) o;
 399                 if (!t->tagged)
 400                         break; /* broken repository */
 401                 o = parse_object(the_repository, &t->tagged->oid);
 402                 deref = 1;
 403                 taggerdate = t->date;
 404         }
 405         if (o && o->type == OBJ_COMMIT) {
 406                 commit = (struct commit *)o;
 407                 from_tag = starts_with(path, "refs/tags/");
 408                 if (taggerdate == TIME_MAX)
 409                         taggerdate = commit->date;
 410         }
 411
 412         add_to_tip_table(oid, path, can_abbreviate_output, commit, taggerdate,
 413                          from_tag, deref);
 414         return 0;
 415 }
 416
 417 static void name_tips(void)
 418 {
 419         int i;
 420
 421         /*
 422          * Try to set better names first, so that worse ones spread
 423          * less.
 424          */
 425         QSORT(tip_table.table, tip_table.nr, cmp_by_tag_and_age);
 426         for (i = 0; i < tip_table.nr; i++) {
 427                 struct tip_table_entry *e = &tip_table.table[i];
 428                 if (e->commit) {
 429                         name_rev(e->commit, e->refname, e->taggerdate,
 430                                  e->from_tag, e->deref);
 431                 }
 432         }
 433 }
 434
 435 static const struct object_id *nth_tip_table_ent(size_t ix, const void *table_)
 436 {
 437         const struct tip_table_entry *table = table_;
 438         return &table[ix].oid;
 439 }
 440
 441 static const char *get_exact_ref_match(const struct object *o)
 442 {
 443         int found;
 444
 445         if (!tip_table.table || !tip_table.nr)
 446                 return NULL;
 447
 448         if (!tip_table.sorted) {
 449                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 450                 tip_table.sorted = 1;
 451         }
 452
 453         found = oid_pos(&o->oid, tip_table.table, tip_table.nr,
 454                         nth_tip_table_ent);
 455         if (0 <= found)
 456                 return tip_table.table[found].refname;
 457         return NULL;
 458 }
 459
 460 /* may return a constant string or use "buf" as scratch space */
 461 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 462 {
 463         struct rev_name *n;
 464         const struct commit *c;
 465
 466         if (o->type != OBJ_COMMIT)
 467                 return get_exact_ref_match(o);
 468         c = (const struct commit *) o;
 469         n = get_commit_rev_name(c);
 470         if (!n)
 471                 return NULL;
 472
 473         if (!n->generation)
 474                 return n->tip_name;
 475         else {
 476                 strbuf_reset(buf);
 477                 strbuf_addstr(buf, n->tip_name);
 478                 strbuf_strip_suffix(buf, "^0");
 479                 strbuf_addf(buf, "~%d", n->generation);
 480                 return buf->buf;
 481         }
 482 }
 483
 484 static void show_name(const struct object *obj,
 485                       const char *caller_name,
 486                       int always, int allow_undefined, int name_only)
 487 {
 488         const char *name;
 489         const struct object_id *oid = &obj->oid;
 490         struct strbuf buf = STRBUF_INIT;
 491
 492         if (!name_only)
 493                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 494         name = get_rev_name(obj, &buf);
 495         if (name)
 496                 printf("%s\n", name);
 497         else if (allow_undefined)
 498                 printf("undefined\n");
 499         else if (always)
 500                 printf("%s\n",
 501                        repo_find_unique_abbrev(the_repository, oid, DEFAULT_ABBREV));
 502         else
 503                 die("cannot describe '%s'", oid_to_hex(oid));
 504         strbuf_release(&buf);
 505 }
 506
 507 static char const * const name_rev_usage[] = {
 508         N_("git name-rev [<options>] <commit>..."),
 509         N_("git name-rev [<options>] --all"),
 510         N_("git name-rev [<options>] --annotate-stdin"),
 511         NULL
 512 };
 513
 514 static void name_rev_line(char *p, struct name_ref_data *data)
 515 {
 516         struct strbuf buf = STRBUF_INIT;
 517         int counter = 0;
 518         char *p_start;
 519         const unsigned hexsz = the_hash_algo->hexsz;
 520
 521         for (p_start = p; *p; p++) {
 522 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 523                 if (!ishex(*p))
 524                         counter = 0;
 525                 else if (++counter == hexsz &&
 526                          !ishex(*(p+1))) {
 527                         struct object_id oid;
 528                         const char *name = NULL;
 529                         char c = *(p+1);
 530                         int p_len = p - p_start + 1;
 531
 532                         counter = 0;
 533
 534                         *(p+1) = 0;
 535                         if (!repo_get_oid(the_repository, p - (hexsz - 1), &oid)) {
 536                                 struct object *o =
 537                                         lookup_object(the_repository, &oid);
 538                                 if (o)
 539                                         name = get_rev_name(o, &buf);
 540                         }
 541                         *(p+1) = c;
 542
 543                         if (!name)
 544                                 continue;
 545
 546                         if (data->name_only)
 547                                 printf("%.*s%s", p_len - hexsz, p_start, name);
 548                         else
 549                                 printf("%.*s (%s)", p_len, p_start, name);
 550                         p_start = p + 1;
 551                 }
 552         }
 553
 554         /* flush */
 555         if (p_start != p)
 556                 fwrite(p_start, p - p_start, 1, stdout);
 557
 558         strbuf_release(&buf);
 559 }
 560
 561 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 562 {
 563         struct object_array revs = OBJECT_ARRAY_INIT;
 564         int all = 0, annotate_stdin = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 565         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 566         struct option opts[] = {
 567                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only ref-based names (no object names)")),
 568                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 569                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 570                                    N_("only use refs matching <pattern>")),
 571                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 572                                    N_("ignore refs matching <pattern>")),
 573                 OPT_GROUP(""),
 574                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 575                 OPT_BOOL(0, "stdin", &transform_stdin, N_("deprecated: use --annotate-stdin instead")),
 576                 OPT_BOOL(0, "annotate-stdin", &annotate_stdin, N_("annotate text from stdin")),
 577                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 578                 OPT_BOOL(0, "always",     &always,
 579                            N_("show abbreviated commit object as fallback")),
 580                 {
 581                         /* A Hidden OPT_BOOL */
 582                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 583                         N_("dereference tags in the input (internal use)"),
 584                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 585                 },
 586                 OPT_END(),
 587         };
 588
 589         init_commit_rev_name(&rev_names);
 590         git_config(git_default_config, NULL);
 591         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 592
 593         if (transform_stdin) {
 594                 warning("--stdin is deprecated. Please use --annotate-stdin instead, "
 595                                         "which is functionally equivalent.\n"
 596                                         "This option will be removed in a future release.");
 597                 annotate_stdin = 1;
 598         }
 599
 600         if (all + annotate_stdin + !!argc > 1) {
 601                 error("Specify either a list, or --all, not both!");
 602                 usage_with_options(name_rev_usage, opts);
 603         }
 604         if (all || annotate_stdin)
 605                 disable_cutoff();
 606
 607         for (; argc; argc--, argv++) {
 608                 struct object_id oid;
 609                 struct object *object;
 610                 struct commit *commit;
 611
 612                 if (repo_get_oid(the_repository, *argv, &oid)) {
 613                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 614                                         *argv);
 615                         continue;
 616                 }
 617
 618                 commit = NULL;
 619                 object = parse_object(the_repository, &oid);
 620                 if (object) {
 621                         struct object *peeled = deref_tag(the_repository,
 622                                                           object, *argv, 0);
 623                         if (peeled && peeled->type == OBJ_COMMIT)
 624                                 commit = (struct commit *)peeled;
 625                 }
 626
 627                 if (!object) {
 628                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 629                                         *argv);
 630                         continue;
 631                 }
 632
 633                 if (commit)
 634                         set_commit_cutoff(commit);
 635
 636                 if (peel_tag) {
 637                         if (!commit) {
 638                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 639                                         *argv);
 640                                 continue;
 641                         }
 642                         object = (struct object *)commit;
 643                 }
 644                 add_object_array(object, *argv, &revs);
 645         }
 646
 647         adjust_cutoff_timestamp_for_slop();
 648
 649         for_each_ref(name_ref, &data);
 650         name_tips();
 651
 652         if (annotate_stdin) {
 653                 struct strbuf sb = STRBUF_INIT;
 654
 655                 while (strbuf_getline(&sb, stdin) != EOF) {
 656                         strbuf_addch(&sb, '\n');
 657                         name_rev_line(sb.buf, &data);
 658                 }
 659                 strbuf_release(&sb);
 660         } else if (all) {
 661                 int i, max;
 662
 663                 max = get_max_object_index();
 664                 for (i = 0; i < max; i++) {
 665                         struct object *obj = get_indexed_object(i);
 666                         if (!obj || obj->type != OBJ_COMMIT)
 667                                 continue;
 668                         show_name(obj, NULL,
 669                                   always, allow_undefined, data.name_only);
 670                 }
 671         } else {
 672                 int i;
 673                 for (i = 0; i < revs.nr; i++)
 674                         show_name(revs.objects[i].item, revs.objects[i].name,
 675                                   always, allow_undefined, data.name_only);
 676         }
 677
 678         UNLEAK(revs);
 679         return 0;
 680 }