builtin/name-rev.c

   1 #include "builtin.h"
   2 #include "environment.h"
   3 #include "gettext.h"
   4 #include "hex.h"
   5 #include "repository.h"
   6 #include "config.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "refs.h"
  10 #include "object-name.h"
  11 #include "pager.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 #include "wildmatch.h"
  18
  19 /*
  20  * One day.  See the 'name a rev shortly after epoch' test in t6120 when
  21  * changing this value
  22  */
  23 #define CUTOFF_DATE_SLOP 86400
  24
  25 struct rev_name {
  26         const char *tip_name;
  27         timestamp_t taggerdate;
  28         int generation;
  29         int distance;
  30         int from_tag;
  31 };
  32
  33 define_commit_slab(commit_rev_name, struct rev_name);
  34
  35 static timestamp_t generation_cutoff = GENERATION_NUMBER_INFINITY;
  36 static timestamp_t cutoff = TIME_MAX;
  37 static struct commit_rev_name rev_names;
  38
  39 /* Disable the cutoff checks entirely */
  40 static void disable_cutoff(void)
  41 {
  42         generation_cutoff = 0;
  43         cutoff = 0;
  44 }
  45
  46 /* Cutoff searching any commits older than this one */
  47 static void set_commit_cutoff(struct commit *commit)
  48 {
  49
  50         if (cutoff > commit->date)
  51                 cutoff = commit->date;
  52
  53         if (generation_cutoff) {
  54                 timestamp_t generation = commit_graph_generation(commit);
  55
  56                 if (generation_cutoff > generation)
  57                         generation_cutoff = generation;
  58         }
  59 }
  60
  61 /* adjust the commit date cutoff with a slop to allow for slightly incorrect
  62  * commit timestamps in case of clock skew.
  63  */
  64 static void adjust_cutoff_timestamp_for_slop(void)
  65 {
  66         if (cutoff) {
  67                 /* check for undeflow */
  68                 if (cutoff > TIME_MIN + CUTOFF_DATE_SLOP)
  69                         cutoff = cutoff - CUTOFF_DATE_SLOP;
  70                 else
  71                         cutoff = TIME_MIN;
  72         }
  73 }
  74
  75 /* Check if a commit is before the cutoff. Prioritize generation numbers
  76  * first, but use the commit timestamp if we lack generation data.
  77  */
  78 static int commit_is_before_cutoff(struct commit *commit)
  79 {
  80         if (generation_cutoff < GENERATION_NUMBER_INFINITY)
  81                 return generation_cutoff &&
  82                         commit_graph_generation(commit) < generation_cutoff;
  83
  84         return commit->date < cutoff;
  85 }
  86
  87 /* How many generations are maximally preferred over _one_ merge traversal? */
  88 #define MERGE_TRAVERSAL_WEIGHT 65535
  89
  90 static int is_valid_rev_name(const struct rev_name *name)
  91 {
  92         return name && name->tip_name;
  93 }
  94
  95 static struct rev_name *get_commit_rev_name(const struct commit *commit)
  96 {
  97         struct rev_name *name = commit_rev_name_peek(&rev_names, commit);
  98
  99         return is_valid_rev_name(name) ? name : NULL;
 100 }
 101
 102 static int effective_distance(int distance, int generation)
 103 {
 104         return distance + (generation > 0 ? MERGE_TRAVERSAL_WEIGHT : 0);
 105 }
 106
 107 static int is_better_name(struct rev_name *name,
 108                           timestamp_t taggerdate,
 109                           int generation,
 110                           int distance,
 111                           int from_tag)
 112 {
 113         int name_distance = effective_distance(name->distance, name->generation);
 114         int new_distance = effective_distance(distance, generation);
 115
 116         /* If both are tags, we prefer the nearer one. */
 117         if (from_tag && name->from_tag)
 118                 return name_distance > new_distance;
 119
 120         /* Favor a tag over a non-tag. */
 121         if (name->from_tag != from_tag)
 122                 return from_tag;
 123
 124         /*
 125          * We are now looking at two non-tags.  Tiebreak to favor
 126          * shorter hops.
 127          */
 128         if (name_distance != new_distance)
 129                 return name_distance > new_distance;
 130
 131         /* ... or tiebreak to favor older date */
 132         if (name->taggerdate != taggerdate)
 133                 return name->taggerdate > taggerdate;
 134
 135         /* keep the current one if we cannot decide */
 136         return 0;
 137 }
 138
 139 static struct rev_name *create_or_update_name(struct commit *commit,
 140                                               timestamp_t taggerdate,
 141                                               int generation, int distance,
 142                                               int from_tag)
 143 {
 144         struct rev_name *name = commit_rev_name_at(&rev_names, commit);
 145
 146         if (is_valid_rev_name(name) &&
 147             !is_better_name(name, taggerdate, generation, distance, from_tag))
 148                 return NULL;
 149
 150         name->taggerdate = taggerdate;
 151         name->generation = generation;
 152         name->distance = distance;
 153         name->from_tag = from_tag;
 154
 155         return name;
 156 }
 157
 158 static char *get_parent_name(const struct rev_name *name, int parent_number)
 159 {
 160         struct strbuf sb = STRBUF_INIT;
 161         size_t len;
 162
 163         strip_suffix(name->tip_name, "^0", &len);
 164         if (name->generation > 0) {
 165                 strbuf_grow(&sb, len +
 166                             1 + decimal_width(name->generation) +
 167                             1 + decimal_width(parent_number));
 168                 strbuf_addf(&sb, "%.*s~%d^%d", (int)len, name->tip_name,
 169                             name->generation, parent_number);
 170         } else {
 171                 strbuf_grow(&sb, len +
 172                             1 + decimal_width(parent_number));
 173                 strbuf_addf(&sb, "%.*s^%d", (int)len, name->tip_name,
 174                             parent_number);
 175         }
 176         return strbuf_detach(&sb, NULL);
 177 }
 178
 179 static void name_rev(struct commit *start_commit,
 180                 const char *tip_name, timestamp_t taggerdate,
 181                 int from_tag, int deref)
 182 {
 183         struct prio_queue queue;
 184         struct commit *commit;
 185         struct commit **parents_to_queue = NULL;
 186         size_t parents_to_queue_nr, parents_to_queue_alloc = 0;
 187         struct rev_name *start_name;
 188
 189         repo_parse_commit(the_repository, start_commit);
 190         if (commit_is_before_cutoff(start_commit))
 191                 return;
 192
 193         start_name = create_or_update_name(start_commit, taggerdate, 0, 0,
 194                                            from_tag);
 195         if (!start_name)
 196                 return;
 197         if (deref)
 198                 start_name->tip_name = xstrfmt("%s^0", tip_name);
 199         else
 200                 start_name->tip_name = xstrdup(tip_name);
 201
 202         memset(&queue, 0, sizeof(queue)); /* Use the prio_queue as LIFO */
 203         prio_queue_put(&queue, start_commit);
 204
 205         while ((commit = prio_queue_get(&queue))) {
 206                 struct rev_name *name = get_commit_rev_name(commit);
 207                 struct commit_list *parents;
 208                 int parent_number = 1;
 209
 210                 parents_to_queue_nr = 0;
 211
 212                 for (parents = commit->parents;
 213                                 parents;
 214                                 parents = parents->next, parent_number++) {
 215                         struct commit *parent = parents->item;
 216                         struct rev_name *parent_name;
 217                         int generation, distance;
 218
 219                         repo_parse_commit(the_repository, parent);
 220                         if (commit_is_before_cutoff(parent))
 221                                 continue;
 222
 223                         if (parent_number > 1) {
 224                                 generation = 0;
 225                                 distance = name->distance + MERGE_TRAVERSAL_WEIGHT;
 226                         } else {
 227                                 generation = name->generation + 1;
 228                                 distance = name->distance + 1;
 229                         }
 230
 231                         parent_name = create_or_update_name(parent, taggerdate,
 232                                                             generation,
 233                                                             distance, from_tag);
 234                         if (parent_name) {
 235                                 if (parent_number > 1)
 236                                         parent_name->tip_name =
 237                                                 get_parent_name(name,
 238                                                                 parent_number);
 239                                 else
 240                                         parent_name->tip_name = name->tip_name;
 241                                 ALLOC_GROW(parents_to_queue,
 242                                            parents_to_queue_nr + 1,
 243                                            parents_to_queue_alloc);
 244                                 parents_to_queue[parents_to_queue_nr] = parent;
 245                                 parents_to_queue_nr++;
 246                         }
 247                 }
 248
 249                 /* The first parent must come out first from the prio_queue */
 250                 while (parents_to_queue_nr)
 251                         prio_queue_put(&queue,
 252                                        parents_to_queue[--parents_to_queue_nr]);
 253         }
 254
 255         clear_prio_queue(&queue);
 256         free(parents_to_queue);
 257 }
 258
 259 static int subpath_matches(const char *path, const char *filter)
 260 {
 261         const char *subpath = path;
 262
 263         while (subpath) {
 264                 if (!wildmatch(filter, subpath, 0))
 265                         return subpath - path;
 266                 subpath = strchr(subpath, '/');
 267                 if (subpath)
 268                         subpath++;
 269         }
 270         return -1;
 271 }
 272
 273 struct name_ref_data {
 274         int tags_only;
 275         int name_only;
 276         struct string_list ref_filters;
 277         struct string_list exclude_filters;
 278 };
 279
 280 static struct tip_table {
 281         struct tip_table_entry {
 282                 struct object_id oid;
 283                 const char *refname;
 284                 struct commit *commit;
 285                 timestamp_t taggerdate;
 286                 unsigned int from_tag:1;
 287                 unsigned int deref:1;
 288         } *table;
 289         int nr;
 290         int alloc;
 291         int sorted;
 292 } tip_table;
 293
 294 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 295                              int shorten_unambiguous, struct commit *commit,
 296                              timestamp_t taggerdate, int from_tag, int deref)
 297 {
 298         char *short_refname = NULL;
 299
 300         if (shorten_unambiguous)
 301                 short_refname = shorten_unambiguous_ref(refname, 0);
 302         else if (skip_prefix(refname, "refs/heads/", &refname))
 303                 ; /* refname already advanced */
 304         else
 305                 skip_prefix(refname, "refs/", &refname);
 306
 307         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 308         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 309         tip_table.table[tip_table.nr].refname = short_refname ?
 310                 short_refname : xstrdup(refname);
 311         tip_table.table[tip_table.nr].commit = commit;
 312         tip_table.table[tip_table.nr].taggerdate = taggerdate;
 313         tip_table.table[tip_table.nr].from_tag = from_tag;
 314         tip_table.table[tip_table.nr].deref = deref;
 315         tip_table.nr++;
 316         tip_table.sorted = 0;
 317 }
 318
 319 static int tipcmp(const void *a_, const void *b_)
 320 {
 321         const struct tip_table_entry *a = a_, *b = b_;
 322         return oidcmp(&a->oid, &b->oid);
 323 }
 324
 325 static int cmp_by_tag_and_age(const void *a_, const void *b_)
 326 {
 327         const struct tip_table_entry *a = a_, *b = b_;
 328         int cmp;
 329
 330         /* Prefer tags. */
 331         cmp = b->from_tag - a->from_tag;
 332         if (cmp)
 333                 return cmp;
 334
 335         /* Older is better. */
 336         if (a->taggerdate < b->taggerdate)
 337                 return -1;
 338         return a->taggerdate != b->taggerdate;
 339 }
 340
 341 static int name_ref(const char *path, const struct object_id *oid,
 342                     int flags UNUSED, void *cb_data)
 343 {
 344         struct object *o = parse_object(the_repository, oid);
 345         struct name_ref_data *data = cb_data;
 346         int can_abbreviate_output = data->tags_only && data->name_only;
 347         int deref = 0;
 348         int from_tag = 0;
 349         struct commit *commit = NULL;
 350         timestamp_t taggerdate = TIME_MAX;
 351
 352         if (data->tags_only && !starts_with(path, "refs/tags/"))
 353                 return 0;
 354
 355         if (data->exclude_filters.nr) {
 356                 struct string_list_item *item;
 357
 358                 for_each_string_list_item(item, &data->exclude_filters) {
 359                         if (subpath_matches(path, item->string) >= 0)
 360                                 return 0;
 361                 }
 362         }
 363
 364         if (data->ref_filters.nr) {
 365                 struct string_list_item *item;
 366                 int matched = 0;
 367
 368                 /* See if any of the patterns match. */
 369                 for_each_string_list_item(item, &data->ref_filters) {
 370                         /*
 371                          * Check all patterns even after finding a match, so
 372                          * that we can see if a match with a subpath exists.
 373                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 374                          * both of which match, the user is showing her
 375                          * willingness to accept a shortened output by having
 376                          * the 'v1.*' in the acceptable refnames, so we
 377                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 378                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 379                          */
 380                         switch (subpath_matches(path, item->string)) {
 381                         case -1: /* did not match */
 382                                 break;
 383                         case 0: /* matched fully */
 384                                 matched = 1;
 385                                 break;
 386                         default: /* matched subpath */
 387                                 matched = 1;
 388                                 can_abbreviate_output = 1;
 389                                 break;
 390                         }
 391                 }
 392
 393                 /* If none of the patterns matched, stop now */
 394                 if (!matched)
 395                         return 0;
 396         }
 397
 398         while (o && o->type == OBJ_TAG) {
 399                 struct tag *t = (struct tag *) o;
 400                 if (!t->tagged)
 401                         break; /* broken repository */
 402                 o = parse_object(the_repository, &t->tagged->oid);
 403                 deref = 1;
 404                 taggerdate = t->date;
 405         }
 406         if (o && o->type == OBJ_COMMIT) {
 407                 commit = (struct commit *)o;
 408                 from_tag = starts_with(path, "refs/tags/");
 409                 if (taggerdate == TIME_MAX)
 410                         taggerdate = commit->date;
 411         }
 412
 413         add_to_tip_table(oid, path, can_abbreviate_output, commit, taggerdate,
 414                          from_tag, deref);
 415         return 0;
 416 }
 417
 418 static void name_tips(void)
 419 {
 420         int i;
 421
 422         /*
 423          * Try to set better names first, so that worse ones spread
 424          * less.
 425          */
 426         QSORT(tip_table.table, tip_table.nr, cmp_by_tag_and_age);
 427         for (i = 0; i < tip_table.nr; i++) {
 428                 struct tip_table_entry *e = &tip_table.table[i];
 429                 if (e->commit) {
 430                         name_rev(e->commit, e->refname, e->taggerdate,
 431                                  e->from_tag, e->deref);
 432                 }
 433         }
 434 }
 435
 436 static const struct object_id *nth_tip_table_ent(size_t ix, const void *table_)
 437 {
 438         const struct tip_table_entry *table = table_;
 439         return &table[ix].oid;
 440 }
 441
 442 static const char *get_exact_ref_match(const struct object *o)
 443 {
 444         int found;
 445
 446         if (!tip_table.table || !tip_table.nr)
 447                 return NULL;
 448
 449         if (!tip_table.sorted) {
 450                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 451                 tip_table.sorted = 1;
 452         }
 453
 454         found = oid_pos(&o->oid, tip_table.table, tip_table.nr,
 455                         nth_tip_table_ent);
 456         if (0 <= found)
 457                 return tip_table.table[found].refname;
 458         return NULL;
 459 }
 460
 461 /* may return a constant string or use "buf" as scratch space */
 462 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 463 {
 464         struct rev_name *n;
 465         const struct commit *c;
 466
 467         if (o->type != OBJ_COMMIT)
 468                 return get_exact_ref_match(o);
 469         c = (const struct commit *) o;
 470         n = get_commit_rev_name(c);
 471         if (!n)
 472                 return NULL;
 473
 474         if (!n->generation)
 475                 return n->tip_name;
 476         else {
 477                 strbuf_reset(buf);
 478                 strbuf_addstr(buf, n->tip_name);
 479                 strbuf_strip_suffix(buf, "^0");
 480                 strbuf_addf(buf, "~%d", n->generation);
 481                 return buf->buf;
 482         }
 483 }
 484
 485 static void show_name(const struct object *obj,
 486                       const char *caller_name,
 487                       int always, int allow_undefined, int name_only)
 488 {
 489         const char *name;
 490         const struct object_id *oid = &obj->oid;
 491         struct strbuf buf = STRBUF_INIT;
 492
 493         if (!name_only)
 494                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 495         name = get_rev_name(obj, &buf);
 496         if (name)
 497                 printf("%s\n", name);
 498         else if (allow_undefined)
 499                 printf("undefined\n");
 500         else if (always)
 501                 printf("%s\n",
 502                        repo_find_unique_abbrev(the_repository, oid, DEFAULT_ABBREV));
 503         else
 504                 die("cannot describe '%s'", oid_to_hex(oid));
 505         strbuf_release(&buf);
 506 }
 507
 508 static char const * const name_rev_usage[] = {
 509         N_("git name-rev [<options>] <commit>..."),
 510         N_("git name-rev [<options>] --all"),
 511         N_("git name-rev [<options>] --annotate-stdin"),
 512         NULL
 513 };
 514
 515 static void name_rev_line(char *p, struct name_ref_data *data)
 516 {
 517         struct strbuf buf = STRBUF_INIT;
 518         int counter = 0;
 519         char *p_start;
 520         const unsigned hexsz = the_hash_algo->hexsz;
 521
 522         for (p_start = p; *p; p++) {
 523 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 524                 if (!ishex(*p))
 525                         counter = 0;
 526                 else if (++counter == hexsz &&
 527                          !ishex(*(p+1))) {
 528                         struct object_id oid;
 529                         const char *name = NULL;
 530                         char c = *(p+1);
 531                         int p_len = p - p_start + 1;
 532
 533                         counter = 0;
 534
 535                         *(p+1) = 0;
 536                         if (!repo_get_oid(the_repository, p - (hexsz - 1), &oid)) {
 537                                 struct object *o =
 538                                         lookup_object(the_repository, &oid);
 539                                 if (o)
 540                                         name = get_rev_name(o, &buf);
 541                         }
 542                         *(p+1) = c;
 543
 544                         if (!name)
 545                                 continue;
 546
 547                         if (data->name_only)
 548                                 printf("%.*s%s", p_len - hexsz, p_start, name);
 549                         else
 550                                 printf("%.*s (%s)", p_len, p_start, name);
 551                         p_start = p + 1;
 552                 }
 553         }
 554
 555         /* flush */
 556         if (p_start != p)
 557                 fwrite(p_start, p - p_start, 1, stdout);
 558
 559         strbuf_release(&buf);
 560 }
 561
 562 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 563 {
 564         struct object_array revs = OBJECT_ARRAY_INIT;
 565         int all = 0, annotate_stdin = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 566         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 567         struct option opts[] = {
 568                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only ref-based names (no object names)")),
 569                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 570                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 571                                    N_("only use refs matching <pattern>")),
 572                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 573                                    N_("ignore refs matching <pattern>")),
 574                 OPT_GROUP(""),
 575                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 576                 OPT_BOOL_F(0,
 577                            "stdin",
 578                            &transform_stdin,
 579                            N_("deprecated: use --annotate-stdin instead"),
 580                            PARSE_OPT_HIDDEN),
 581                 OPT_BOOL(0, "annotate-stdin", &annotate_stdin, N_("annotate text from stdin")),
 582                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 583                 OPT_BOOL(0, "always",     &always,
 584                            N_("show abbreviated commit object as fallback")),
 585                 OPT_HIDDEN_BOOL(0, "peel-tag", &peel_tag,
 586                            N_("dereference tags in the input (internal use)")),
 587                 OPT_END(),
 588         };
 589
 590         init_commit_rev_name(&rev_names);
 591         git_config(git_default_config, NULL);
 592         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 593
 594         if (transform_stdin) {
 595                 warning("--stdin is deprecated. Please use --annotate-stdin instead, "
 596                                         "which is functionally equivalent.\n"
 597                                         "This option will be removed in a future release.");
 598                 annotate_stdin = 1;
 599         }
 600
 601         if (all + annotate_stdin + !!argc > 1) {
 602                 error("Specify either a list, or --all, not both!");
 603                 usage_with_options(name_rev_usage, opts);
 604         }
 605         if (all || annotate_stdin)
 606                 disable_cutoff();
 607
 608         for (; argc; argc--, argv++) {
 609                 struct object_id oid;
 610                 struct object *object;
 611                 struct commit *commit;
 612
 613                 if (repo_get_oid(the_repository, *argv, &oid)) {
 614                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 615                                         *argv);
 616                         continue;
 617                 }
 618
 619                 commit = NULL;
 620                 object = parse_object(the_repository, &oid);
 621                 if (object) {
 622                         struct object *peeled = deref_tag(the_repository,
 623                                                           object, *argv, 0);
 624                         if (peeled && peeled->type == OBJ_COMMIT)
 625                                 commit = (struct commit *)peeled;
 626                 }
 627
 628                 if (!object) {
 629                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 630                                         *argv);
 631                         continue;
 632                 }
 633
 634                 if (commit)
 635                         set_commit_cutoff(commit);
 636
 637                 if (peel_tag) {
 638                         if (!commit) {
 639                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 640                                         *argv);
 641                                 continue;
 642                         }
 643                         object = (struct object *)commit;
 644                 }
 645                 add_object_array(object, *argv, &revs);
 646         }
 647
 648         adjust_cutoff_timestamp_for_slop();
 649
 650         for_each_ref(name_ref, &data);
 651         name_tips();
 652
 653         if (annotate_stdin) {
 654                 struct strbuf sb = STRBUF_INIT;
 655
 656                 while (strbuf_getline(&sb, stdin) != EOF) {
 657                         strbuf_addch(&sb, '\n');
 658                         name_rev_line(sb.buf, &data);
 659                 }
 660                 strbuf_release(&sb);
 661         } else if (all) {
 662                 int i, max;
 663
 664                 max = get_max_object_index();
 665                 for (i = 0; i < max; i++) {
 666                         struct object *obj = get_indexed_object(i);
 667                         if (!obj || obj->type != OBJ_COMMIT)
 668                                 continue;
 669                         show_name(obj, NULL,
 670                                   always, allow_undefined, data.name_only);
 671                 }
 672         } else {
 673                 int i;
 674                 for (i = 0; i < revs.nr; i++)
 675                         show_name(revs.objects[i].item, revs.objects[i].name,
 676                                   always, allow_undefined, data.name_only);
 677         }
 678
 679         UNLEAK(revs);
 680         return 0;
 681 }