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 "pager.h"
  13 #include "parse-options.h"
  14 #include "prio-queue.h"
  15 #include "hash-lookup.h"
  16 #include "commit-slab.h"
  17 #include "commit-graph.h"
  18 #include "wildmatch.h"
  19
  20 /*
  21  * One day.  See the 'name a rev shortly after epoch' test in t6120 when
  22  * changing this value
  23  */
  24 #define CUTOFF_DATE_SLOP 86400
  25
  26 struct rev_name {
  27         const char *tip_name;
  28         timestamp_t taggerdate;
  29         int generation;
  30         int distance;
  31         int from_tag;
  32 };
  33
  34 define_commit_slab(commit_rev_name, struct rev_name);
  35
  36 static timestamp_t generation_cutoff = GENERATION_NUMBER_INFINITY;
  37 static timestamp_t cutoff = TIME_MAX;
  38 static struct commit_rev_name rev_names;
  39
  40 /* Disable the cutoff checks entirely */
  41 static void disable_cutoff(void)
  42 {
  43         generation_cutoff = 0;
  44         cutoff = 0;
  45 }
  46
  47 /* Cutoff searching any commits older than this one */
  48 static void set_commit_cutoff(struct commit *commit)
  49 {
  50
  51         if (cutoff > commit->date)
  52                 cutoff = commit->date;
  53
  54         if (generation_cutoff) {
  55                 timestamp_t generation = commit_graph_generation(commit);
  56
  57                 if (generation_cutoff > generation)
  58                         generation_cutoff = generation;
  59         }
  60 }
  61
  62 /* adjust the commit date cutoff with a slop to allow for slightly incorrect
  63  * commit timestamps in case of clock skew.
  64  */
  65 static void adjust_cutoff_timestamp_for_slop(void)
  66 {
  67         if (cutoff) {
  68                 /* check for undeflow */
  69                 if (cutoff > TIME_MIN + CUTOFF_DATE_SLOP)
  70                         cutoff = cutoff - CUTOFF_DATE_SLOP;
  71                 else
  72                         cutoff = TIME_MIN;
  73         }
  74 }
  75
  76 /* Check if a commit is before the cutoff. Prioritize generation numbers
  77  * first, but use the commit timestamp if we lack generation data.
  78  */
  79 static int commit_is_before_cutoff(struct commit *commit)
  80 {
  81         if (generation_cutoff < GENERATION_NUMBER_INFINITY)
  82                 return generation_cutoff &&
  83                         commit_graph_generation(commit) < generation_cutoff;
  84
  85         return commit->date < cutoff;
  86 }
  87
  88 /* How many generations are maximally preferred over _one_ merge traversal? */
  89 #define MERGE_TRAVERSAL_WEIGHT 65535
  90
  91 static int is_valid_rev_name(const struct rev_name *name)
  92 {
  93         return name && name->tip_name;
  94 }
  95
  96 static struct rev_name *get_commit_rev_name(const struct commit *commit)
  97 {
  98         struct rev_name *name = commit_rev_name_peek(&rev_names, commit);
  99
 100         return is_valid_rev_name(name) ? name : NULL;
 101 }
 102
 103 static int effective_distance(int distance, int generation)
 104 {
 105         return distance + (generation > 0 ? MERGE_TRAVERSAL_WEIGHT : 0);
 106 }
 107
 108 static int is_better_name(struct rev_name *name,
 109                           timestamp_t taggerdate,
 110                           int generation,
 111                           int distance,
 112                           int from_tag)
 113 {
 114         int name_distance = effective_distance(name->distance, name->generation);
 115         int new_distance = effective_distance(distance, generation);
 116
 117         /* If both are tags, we prefer the nearer one. */
 118         if (from_tag && name->from_tag)
 119                 return name_distance > new_distance;
 120
 121         /* Favor a tag over a non-tag. */
 122         if (name->from_tag != from_tag)
 123                 return from_tag;
 124
 125         /*
 126          * We are now looking at two non-tags.  Tiebreak to favor
 127          * shorter hops.
 128          */
 129         if (name_distance != new_distance)
 130                 return name_distance > new_distance;
 131
 132         /* ... or tiebreak to favor older date */
 133         if (name->taggerdate != taggerdate)
 134                 return name->taggerdate > taggerdate;
 135
 136         /* keep the current one if we cannot decide */
 137         return 0;
 138 }
 139
 140 static struct rev_name *create_or_update_name(struct commit *commit,
 141                                               timestamp_t taggerdate,
 142                                               int generation, int distance,
 143                                               int from_tag)
 144 {
 145         struct rev_name *name = commit_rev_name_at(&rev_names, commit);
 146
 147         if (is_valid_rev_name(name) &&
 148             !is_better_name(name, taggerdate, generation, distance, from_tag))
 149                 return NULL;
 150
 151         name->taggerdate = taggerdate;
 152         name->generation = generation;
 153         name->distance = distance;
 154         name->from_tag = from_tag;
 155
 156         return name;
 157 }
 158
 159 static char *get_parent_name(const struct rev_name *name, int parent_number)
 160 {
 161         struct strbuf sb = STRBUF_INIT;
 162         size_t len;
 163
 164         strip_suffix(name->tip_name, "^0", &len);
 165         if (name->generation > 0) {
 166                 strbuf_grow(&sb, len +
 167                             1 + decimal_width(name->generation) +
 168                             1 + decimal_width(parent_number));
 169                 strbuf_addf(&sb, "%.*s~%d^%d", (int)len, name->tip_name,
 170                             name->generation, parent_number);
 171         } else {
 172                 strbuf_grow(&sb, len +
 173                             1 + decimal_width(parent_number));
 174                 strbuf_addf(&sb, "%.*s^%d", (int)len, name->tip_name,
 175                             parent_number);
 176         }
 177         return strbuf_detach(&sb, NULL);
 178 }
 179
 180 static void name_rev(struct commit *start_commit,
 181                 const char *tip_name, timestamp_t taggerdate,
 182                 int from_tag, int deref)
 183 {
 184         struct prio_queue queue;
 185         struct commit *commit;
 186         struct commit **parents_to_queue = NULL;
 187         size_t parents_to_queue_nr, parents_to_queue_alloc = 0;
 188         struct rev_name *start_name;
 189
 190         repo_parse_commit(the_repository, start_commit);
 191         if (commit_is_before_cutoff(start_commit))
 192                 return;
 193
 194         start_name = create_or_update_name(start_commit, taggerdate, 0, 0,
 195                                            from_tag);
 196         if (!start_name)
 197                 return;
 198         if (deref)
 199                 start_name->tip_name = xstrfmt("%s^0", tip_name);
 200         else
 201                 start_name->tip_name = xstrdup(tip_name);
 202
 203         memset(&queue, 0, sizeof(queue)); /* Use the prio_queue as LIFO */
 204         prio_queue_put(&queue, start_commit);
 205
 206         while ((commit = prio_queue_get(&queue))) {
 207                 struct rev_name *name = get_commit_rev_name(commit);
 208                 struct commit_list *parents;
 209                 int parent_number = 1;
 210
 211                 parents_to_queue_nr = 0;
 212
 213                 for (parents = commit->parents;
 214                                 parents;
 215                                 parents = parents->next, parent_number++) {
 216                         struct commit *parent = parents->item;
 217                         struct rev_name *parent_name;
 218                         int generation, distance;
 219
 220                         repo_parse_commit(the_repository, parent);
 221                         if (commit_is_before_cutoff(parent))
 222                                 continue;
 223
 224                         if (parent_number > 1) {
 225                                 generation = 0;
 226                                 distance = name->distance + MERGE_TRAVERSAL_WEIGHT;
 227                         } else {
 228                                 generation = name->generation + 1;
 229                                 distance = name->distance + 1;
 230                         }
 231
 232                         parent_name = create_or_update_name(parent, taggerdate,
 233                                                             generation,
 234                                                             distance, from_tag);
 235                         if (parent_name) {
 236                                 if (parent_number > 1)
 237                                         parent_name->tip_name =
 238                                                 get_parent_name(name,
 239                                                                 parent_number);
 240                                 else
 241                                         parent_name->tip_name = name->tip_name;
 242                                 ALLOC_GROW(parents_to_queue,
 243                                            parents_to_queue_nr + 1,
 244                                            parents_to_queue_alloc);
 245                                 parents_to_queue[parents_to_queue_nr] = parent;
 246                                 parents_to_queue_nr++;
 247                         }
 248                 }
 249
 250                 /* The first parent must come out first from the prio_queue */
 251                 while (parents_to_queue_nr)
 252                         prio_queue_put(&queue,
 253                                        parents_to_queue[--parents_to_queue_nr]);
 254         }
 255
 256         clear_prio_queue(&queue);
 257         free(parents_to_queue);
 258 }
 259
 260 static int subpath_matches(const char *path, const char *filter)
 261 {
 262         const char *subpath = path;
 263
 264         while (subpath) {
 265                 if (!wildmatch(filter, subpath, 0))
 266                         return subpath - path;
 267                 subpath = strchr(subpath, '/');
 268                 if (subpath)
 269                         subpath++;
 270         }
 271         return -1;
 272 }
 273
 274 struct name_ref_data {
 275         int tags_only;
 276         int name_only;
 277         struct string_list ref_filters;
 278         struct string_list exclude_filters;
 279 };
 280
 281 static struct tip_table {
 282         struct tip_table_entry {
 283                 struct object_id oid;
 284                 const char *refname;
 285                 struct commit *commit;
 286                 timestamp_t taggerdate;
 287                 unsigned int from_tag:1;
 288                 unsigned int deref:1;
 289         } *table;
 290         int nr;
 291         int alloc;
 292         int sorted;
 293 } tip_table;
 294
 295 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 296                              int shorten_unambiguous, struct commit *commit,
 297                              timestamp_t taggerdate, int from_tag, int deref)
 298 {
 299         char *short_refname = NULL;
 300
 301         if (shorten_unambiguous)
 302                 short_refname = shorten_unambiguous_ref(refname, 0);
 303         else if (skip_prefix(refname, "refs/heads/", &refname))
 304                 ; /* refname already advanced */
 305         else
 306                 skip_prefix(refname, "refs/", &refname);
 307
 308         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 309         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 310         tip_table.table[tip_table.nr].refname = short_refname ?
 311                 short_refname : xstrdup(refname);
 312         tip_table.table[tip_table.nr].commit = commit;
 313         tip_table.table[tip_table.nr].taggerdate = taggerdate;
 314         tip_table.table[tip_table.nr].from_tag = from_tag;
 315         tip_table.table[tip_table.nr].deref = deref;
 316         tip_table.nr++;
 317         tip_table.sorted = 0;
 318 }
 319
 320 static int tipcmp(const void *a_, const void *b_)
 321 {
 322         const struct tip_table_entry *a = a_, *b = b_;
 323         return oidcmp(&a->oid, &b->oid);
 324 }
 325
 326 static int cmp_by_tag_and_age(const void *a_, const void *b_)
 327 {
 328         const struct tip_table_entry *a = a_, *b = b_;
 329         int cmp;
 330
 331         /* Prefer tags. */
 332         cmp = b->from_tag - a->from_tag;
 333         if (cmp)
 334                 return cmp;
 335
 336         /* Older is better. */
 337         if (a->taggerdate < b->taggerdate)
 338                 return -1;
 339         return a->taggerdate != b->taggerdate;
 340 }
 341
 342 static int name_ref(const char *path, const struct object_id *oid,
 343                     int flags UNUSED, void *cb_data)
 344 {
 345         struct object *o = parse_object(the_repository, oid);
 346         struct name_ref_data *data = cb_data;
 347         int can_abbreviate_output = data->tags_only && data->name_only;
 348         int deref = 0;
 349         int from_tag = 0;
 350         struct commit *commit = NULL;
 351         timestamp_t taggerdate = TIME_MAX;
 352
 353         if (data->tags_only && !starts_with(path, "refs/tags/"))
 354                 return 0;
 355
 356         if (data->exclude_filters.nr) {
 357                 struct string_list_item *item;
 358
 359                 for_each_string_list_item(item, &data->exclude_filters) {
 360                         if (subpath_matches(path, item->string) >= 0)
 361                                 return 0;
 362                 }
 363         }
 364
 365         if (data->ref_filters.nr) {
 366                 struct string_list_item *item;
 367                 int matched = 0;
 368
 369                 /* See if any of the patterns match. */
 370                 for_each_string_list_item(item, &data->ref_filters) {
 371                         /*
 372                          * Check all patterns even after finding a match, so
 373                          * that we can see if a match with a subpath exists.
 374                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 375                          * both of which match, the user is showing her
 376                          * willingness to accept a shortened output by having
 377                          * the 'v1.*' in the acceptable refnames, so we
 378                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 379                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 380                          */
 381                         switch (subpath_matches(path, item->string)) {
 382                         case -1: /* did not match */
 383                                 break;
 384                         case 0: /* matched fully */
 385                                 matched = 1;
 386                                 break;
 387                         default: /* matched subpath */
 388                                 matched = 1;
 389                                 can_abbreviate_output = 1;
 390                                 break;
 391                         }
 392                 }
 393
 394                 /* If none of the patterns matched, stop now */
 395                 if (!matched)
 396                         return 0;
 397         }
 398
 399         while (o && o->type == OBJ_TAG) {
 400                 struct tag *t = (struct tag *) o;
 401                 if (!t->tagged)
 402                         break; /* broken repository */
 403                 o = parse_object(the_repository, &t->tagged->oid);
 404                 deref = 1;
 405                 taggerdate = t->date;
 406         }
 407         if (o && o->type == OBJ_COMMIT) {
 408                 commit = (struct commit *)o;
 409                 from_tag = starts_with(path, "refs/tags/");
 410                 if (taggerdate == TIME_MAX)
 411                         taggerdate = commit->date;
 412         }
 413
 414         add_to_tip_table(oid, path, can_abbreviate_output, commit, taggerdate,
 415                          from_tag, deref);
 416         return 0;
 417 }
 418
 419 static void name_tips(void)
 420 {
 421         int i;
 422
 423         /*
 424          * Try to set better names first, so that worse ones spread
 425          * less.
 426          */
 427         QSORT(tip_table.table, tip_table.nr, cmp_by_tag_and_age);
 428         for (i = 0; i < tip_table.nr; i++) {
 429                 struct tip_table_entry *e = &tip_table.table[i];
 430                 if (e->commit) {
 431                         name_rev(e->commit, e->refname, e->taggerdate,
 432                                  e->from_tag, e->deref);
 433                 }
 434         }
 435 }
 436
 437 static const struct object_id *nth_tip_table_ent(size_t ix, const void *table_)
 438 {
 439         const struct tip_table_entry *table = table_;
 440         return &table[ix].oid;
 441 }
 442
 443 static const char *get_exact_ref_match(const struct object *o)
 444 {
 445         int found;
 446
 447         if (!tip_table.table || !tip_table.nr)
 448                 return NULL;
 449
 450         if (!tip_table.sorted) {
 451                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 452                 tip_table.sorted = 1;
 453         }
 454
 455         found = oid_pos(&o->oid, tip_table.table, tip_table.nr,
 456                         nth_tip_table_ent);
 457         if (0 <= found)
 458                 return tip_table.table[found].refname;
 459         return NULL;
 460 }
 461
 462 /* may return a constant string or use "buf" as scratch space */
 463 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 464 {
 465         struct rev_name *n;
 466         const struct commit *c;
 467
 468         if (o->type != OBJ_COMMIT)
 469                 return get_exact_ref_match(o);
 470         c = (const struct commit *) o;
 471         n = get_commit_rev_name(c);
 472         if (!n)
 473                 return NULL;
 474
 475         if (!n->generation)
 476                 return n->tip_name;
 477         else {
 478                 strbuf_reset(buf);
 479                 strbuf_addstr(buf, n->tip_name);
 480                 strbuf_strip_suffix(buf, "^0");
 481                 strbuf_addf(buf, "~%d", n->generation);
 482                 return buf->buf;
 483         }
 484 }
 485
 486 static void show_name(const struct object *obj,
 487                       const char *caller_name,
 488                       int always, int allow_undefined, int name_only)
 489 {
 490         const char *name;
 491         const struct object_id *oid = &obj->oid;
 492         struct strbuf buf = STRBUF_INIT;
 493
 494         if (!name_only)
 495                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 496         name = get_rev_name(obj, &buf);
 497         if (name)
 498                 printf("%s\n", name);
 499         else if (allow_undefined)
 500                 printf("undefined\n");
 501         else if (always)
 502                 printf("%s\n",
 503                        repo_find_unique_abbrev(the_repository, oid, DEFAULT_ABBREV));
 504         else
 505                 die("cannot describe '%s'", oid_to_hex(oid));
 506         strbuf_release(&buf);
 507 }
 508
 509 static char const * const name_rev_usage[] = {
 510         N_("git name-rev [<options>] <commit>..."),
 511         N_("git name-rev [<options>] --all"),
 512         N_("git name-rev [<options>] --annotate-stdin"),
 513         NULL
 514 };
 515
 516 static void name_rev_line(char *p, struct name_ref_data *data)
 517 {
 518         struct strbuf buf = STRBUF_INIT;
 519         int counter = 0;
 520         char *p_start;
 521         const unsigned hexsz = the_hash_algo->hexsz;
 522
 523         for (p_start = p; *p; p++) {
 524 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 525                 if (!ishex(*p))
 526                         counter = 0;
 527                 else if (++counter == hexsz &&
 528                          !ishex(*(p+1))) {
 529                         struct object_id oid;
 530                         const char *name = NULL;
 531                         char c = *(p+1);
 532                         int p_len = p - p_start + 1;
 533
 534                         counter = 0;
 535
 536                         *(p+1) = 0;
 537                         if (!repo_get_oid(the_repository, p - (hexsz - 1), &oid)) {
 538                                 struct object *o =
 539                                         lookup_object(the_repository, &oid);
 540                                 if (o)
 541                                         name = get_rev_name(o, &buf);
 542                         }
 543                         *(p+1) = c;
 544
 545                         if (!name)
 546                                 continue;
 547
 548                         if (data->name_only)
 549                                 printf("%.*s%s", p_len - hexsz, p_start, name);
 550                         else
 551                                 printf("%.*s (%s)", p_len, p_start, name);
 552                         p_start = p + 1;
 553                 }
 554         }
 555
 556         /* flush */
 557         if (p_start != p)
 558                 fwrite(p_start, p - p_start, 1, stdout);
 559
 560         strbuf_release(&buf);
 561 }
 562
 563 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 564 {
 565         struct object_array revs = OBJECT_ARRAY_INIT;
 566         int all = 0, annotate_stdin = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 567         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 568         struct option opts[] = {
 569                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only ref-based names (no object names)")),
 570                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 571                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 572                                    N_("only use refs matching <pattern>")),
 573                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 574                                    N_("ignore refs matching <pattern>")),
 575                 OPT_GROUP(""),
 576                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 577                 OPT_BOOL_F(0,
 578                            "stdin",
 579                            &transform_stdin,
 580                            N_("deprecated: use --annotate-stdin instead"),
 581                            PARSE_OPT_HIDDEN),
 582                 OPT_BOOL(0, "annotate-stdin", &annotate_stdin, N_("annotate text from stdin")),
 583                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 584                 OPT_BOOL(0, "always",     &always,
 585                            N_("show abbreviated commit object as fallback")),
 586                 {
 587                         /* A Hidden OPT_BOOL */
 588                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 589                         N_("dereference tags in the input (internal use)"),
 590                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 591                 },
 592                 OPT_END(),
 593         };
 594
 595         init_commit_rev_name(&rev_names);
 596         git_config(git_default_config, NULL);
 597         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 598
 599         if (transform_stdin) {
 600                 warning("--stdin is deprecated. Please use --annotate-stdin instead, "
 601                                         "which is functionally equivalent.\n"
 602                                         "This option will be removed in a future release.");
 603                 annotate_stdin = 1;
 604         }
 605
 606         if (all + annotate_stdin + !!argc > 1) {
 607                 error("Specify either a list, or --all, not both!");
 608                 usage_with_options(name_rev_usage, opts);
 609         }
 610         if (all || annotate_stdin)
 611                 disable_cutoff();
 612
 613         for (; argc; argc--, argv++) {
 614                 struct object_id oid;
 615                 struct object *object;
 616                 struct commit *commit;
 617
 618                 if (repo_get_oid(the_repository, *argv, &oid)) {
 619                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 620                                         *argv);
 621                         continue;
 622                 }
 623
 624                 commit = NULL;
 625                 object = parse_object(the_repository, &oid);
 626                 if (object) {
 627                         struct object *peeled = deref_tag(the_repository,
 628                                                           object, *argv, 0);
 629                         if (peeled && peeled->type == OBJ_COMMIT)
 630                                 commit = (struct commit *)peeled;
 631                 }
 632
 633                 if (!object) {
 634                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 635                                         *argv);
 636                         continue;
 637                 }
 638
 639                 if (commit)
 640                         set_commit_cutoff(commit);
 641
 642                 if (peel_tag) {
 643                         if (!commit) {
 644                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 645                                         *argv);
 646                                 continue;
 647                         }
 648                         object = (struct object *)commit;
 649                 }
 650                 add_object_array(object, *argv, &revs);
 651         }
 652
 653         adjust_cutoff_timestamp_for_slop();
 654
 655         for_each_ref(name_ref, &data);
 656         name_tips();
 657
 658         if (annotate_stdin) {
 659                 struct strbuf sb = STRBUF_INIT;
 660
 661                 while (strbuf_getline(&sb, stdin) != EOF) {
 662                         strbuf_addch(&sb, '\n');
 663                         name_rev_line(sb.buf, &data);
 664                 }
 665                 strbuf_release(&sb);
 666         } else if (all) {
 667                 int i, max;
 668
 669                 max = get_max_object_index();
 670                 for (i = 0; i < max; i++) {
 671                         struct object *obj = get_indexed_object(i);
 672                         if (!obj || obj->type != OBJ_COMMIT)
 673                                 continue;
 674                         show_name(obj, NULL,
 675                                   always, allow_undefined, data.name_only);
 676                 }
 677         } else {
 678                 int i;
 679                 for (i = 0; i < revs.nr; i++)
 680                         show_name(revs.objects[i].item, revs.objects[i].name,
 681                                   always, allow_undefined, data.name_only);
 682         }
 683
 684         UNLEAK(revs);
 685         return 0;
 686 }