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 #include "mem-pool.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                              struct mem_pool *string_pool)
 161 {
 162         size_t len;
 163
 164         strip_suffix(name->tip_name, "^0", &len);
 165         if (name->generation > 0) {
 166                 return mem_pool_strfmt(string_pool, "%.*s~%d^%d",
 167                                        (int)len, name->tip_name,
 168                                        name->generation, parent_number);
 169         } else {
 170                 return mem_pool_strfmt(string_pool, "%.*s^%d",
 171                                        (int)len, name->tip_name, parent_number);
 172         }
 173 }
 174
 175 static void name_rev(struct commit *start_commit,
 176                 const char *tip_name, timestamp_t taggerdate,
 177                 int from_tag, int deref, struct mem_pool *string_pool)
 178 {
 179         struct prio_queue queue;
 180         struct commit *commit;
 181         struct commit **parents_to_queue = NULL;
 182         size_t parents_to_queue_nr, parents_to_queue_alloc = 0;
 183         struct rev_name *start_name;
 184
 185         repo_parse_commit(the_repository, start_commit);
 186         if (commit_is_before_cutoff(start_commit))
 187                 return;
 188
 189         start_name = create_or_update_name(start_commit, taggerdate, 0, 0,
 190                                            from_tag);
 191         if (!start_name)
 192                 return;
 193         if (deref)
 194                 start_name->tip_name = mem_pool_strfmt(string_pool, "%s^0",
 195                                                        tip_name);
 196         else
 197                 start_name->tip_name = mem_pool_strdup(string_pool, tip_name);
 198
 199         memset(&queue, 0, sizeof(queue)); /* Use the prio_queue as LIFO */
 200         prio_queue_put(&queue, start_commit);
 201
 202         while ((commit = prio_queue_get(&queue))) {
 203                 struct rev_name *name = get_commit_rev_name(commit);
 204                 struct commit_list *parents;
 205                 int parent_number = 1;
 206
 207                 parents_to_queue_nr = 0;
 208
 209                 for (parents = commit->parents;
 210                                 parents;
 211                                 parents = parents->next, parent_number++) {
 212                         struct commit *parent = parents->item;
 213                         struct rev_name *parent_name;
 214                         int generation, distance;
 215
 216                         repo_parse_commit(the_repository, parent);
 217                         if (commit_is_before_cutoff(parent))
 218                                 continue;
 219
 220                         if (parent_number > 1) {
 221                                 generation = 0;
 222                                 distance = name->distance + MERGE_TRAVERSAL_WEIGHT;
 223                         } else {
 224                                 generation = name->generation + 1;
 225                                 distance = name->distance + 1;
 226                         }
 227
 228                         parent_name = create_or_update_name(parent, taggerdate,
 229                                                             generation,
 230                                                             distance, from_tag);
 231                         if (parent_name) {
 232                                 if (parent_number > 1)
 233                                         parent_name->tip_name =
 234                                                 get_parent_name(name,
 235                                                                 parent_number,
 236                                                                 string_pool);
 237                                 else
 238                                         parent_name->tip_name = name->tip_name;
 239                                 ALLOC_GROW(parents_to_queue,
 240                                            parents_to_queue_nr + 1,
 241                                            parents_to_queue_alloc);
 242                                 parents_to_queue[parents_to_queue_nr] = parent;
 243                                 parents_to_queue_nr++;
 244                         }
 245                 }
 246
 247                 /* The first parent must come out first from the prio_queue */
 248                 while (parents_to_queue_nr)
 249                         prio_queue_put(&queue,
 250                                        parents_to_queue[--parents_to_queue_nr]);
 251         }
 252
 253         clear_prio_queue(&queue);
 254         free(parents_to_queue);
 255 }
 256
 257 static int subpath_matches(const char *path, const char *filter)
 258 {
 259         const char *subpath = path;
 260
 261         while (subpath) {
 262                 if (!wildmatch(filter, subpath, 0))
 263                         return subpath - path;
 264                 subpath = strchr(subpath, '/');
 265                 if (subpath)
 266                         subpath++;
 267         }
 268         return -1;
 269 }
 270
 271 struct name_ref_data {
 272         int tags_only;
 273         int name_only;
 274         struct string_list ref_filters;
 275         struct string_list exclude_filters;
 276 };
 277
 278 static struct tip_table {
 279         struct tip_table_entry {
 280                 struct object_id oid;
 281                 const char *refname;
 282                 struct commit *commit;
 283                 timestamp_t taggerdate;
 284                 unsigned int from_tag:1;
 285                 unsigned int deref:1;
 286         } *table;
 287         int nr;
 288         int alloc;
 289         int sorted;
 290 } tip_table;
 291
 292 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 293                              int shorten_unambiguous, struct commit *commit,
 294                              timestamp_t taggerdate, int from_tag, int deref)
 295 {
 296         char *short_refname = NULL;
 297
 298         if (shorten_unambiguous)
 299                 short_refname = shorten_unambiguous_ref(refname, 0);
 300         else if (skip_prefix(refname, "refs/heads/", &refname))
 301                 ; /* refname already advanced */
 302         else
 303                 skip_prefix(refname, "refs/", &refname);
 304
 305         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 306         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 307         tip_table.table[tip_table.nr].refname = short_refname ?
 308                 short_refname : xstrdup(refname);
 309         tip_table.table[tip_table.nr].commit = commit;
 310         tip_table.table[tip_table.nr].taggerdate = taggerdate;
 311         tip_table.table[tip_table.nr].from_tag = from_tag;
 312         tip_table.table[tip_table.nr].deref = deref;
 313         tip_table.nr++;
 314         tip_table.sorted = 0;
 315 }
 316
 317 static int tipcmp(const void *a_, const void *b_)
 318 {
 319         const struct tip_table_entry *a = a_, *b = b_;
 320         return oidcmp(&a->oid, &b->oid);
 321 }
 322
 323 static int cmp_by_tag_and_age(const void *a_, const void *b_)
 324 {
 325         const struct tip_table_entry *a = a_, *b = b_;
 326         int cmp;
 327
 328         /* Prefer tags. */
 329         cmp = b->from_tag - a->from_tag;
 330         if (cmp)
 331                 return cmp;
 332
 333         /* Older is better. */
 334         if (a->taggerdate < b->taggerdate)
 335                 return -1;
 336         return a->taggerdate != b->taggerdate;
 337 }
 338
 339 static int name_ref(const char *path, const struct object_id *oid,
 340                     int flags UNUSED, void *cb_data)
 341 {
 342         struct object *o = parse_object(the_repository, oid);
 343         struct name_ref_data *data = cb_data;
 344         int can_abbreviate_output = data->tags_only && data->name_only;
 345         int deref = 0;
 346         int from_tag = 0;
 347         struct commit *commit = NULL;
 348         timestamp_t taggerdate = TIME_MAX;
 349
 350         if (data->tags_only && !starts_with(path, "refs/tags/"))
 351                 return 0;
 352
 353         if (data->exclude_filters.nr) {
 354                 struct string_list_item *item;
 355
 356                 for_each_string_list_item(item, &data->exclude_filters) {
 357                         if (subpath_matches(path, item->string) >= 0)
 358                                 return 0;
 359                 }
 360         }
 361
 362         if (data->ref_filters.nr) {
 363                 struct string_list_item *item;
 364                 int matched = 0;
 365
 366                 /* See if any of the patterns match. */
 367                 for_each_string_list_item(item, &data->ref_filters) {
 368                         /*
 369                          * Check all patterns even after finding a match, so
 370                          * that we can see if a match with a subpath exists.
 371                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 372                          * both of which match, the user is showing her
 373                          * willingness to accept a shortened output by having
 374                          * the 'v1.*' in the acceptable refnames, so we
 375                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 376                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 377                          */
 378                         switch (subpath_matches(path, item->string)) {
 379                         case -1: /* did not match */
 380                                 break;
 381                         case 0: /* matched fully */
 382                                 matched = 1;
 383                                 break;
 384                         default: /* matched subpath */
 385                                 matched = 1;
 386                                 can_abbreviate_output = 1;
 387                                 break;
 388                         }
 389                 }
 390
 391                 /* If none of the patterns matched, stop now */
 392                 if (!matched)
 393                         return 0;
 394         }
 395
 396         while (o && o->type == OBJ_TAG) {
 397                 struct tag *t = (struct tag *) o;
 398                 if (!t->tagged)
 399                         break; /* broken repository */
 400                 o = parse_object(the_repository, &t->tagged->oid);
 401                 deref = 1;
 402                 taggerdate = t->date;
 403         }
 404         if (o && o->type == OBJ_COMMIT) {
 405                 commit = (struct commit *)o;
 406                 from_tag = starts_with(path, "refs/tags/");
 407                 if (taggerdate == TIME_MAX)
 408                         taggerdate = commit->date;
 409         }
 410
 411         add_to_tip_table(oid, path, can_abbreviate_output, commit, taggerdate,
 412                          from_tag, deref);
 413         return 0;
 414 }
 415
 416 static void name_tips(struct mem_pool *string_pool)
 417 {
 418         int i;
 419
 420         /*
 421          * Try to set better names first, so that worse ones spread
 422          * less.
 423          */
 424         QSORT(tip_table.table, tip_table.nr, cmp_by_tag_and_age);
 425         for (i = 0; i < tip_table.nr; i++) {
 426                 struct tip_table_entry *e = &tip_table.table[i];
 427                 if (e->commit) {
 428                         name_rev(e->commit, e->refname, e->taggerdate,
 429                                  e->from_tag, e->deref, string_pool);
 430                 }
 431         }
 432 }
 433
 434 static const struct object_id *nth_tip_table_ent(size_t ix, const void *table_)
 435 {
 436         const struct tip_table_entry *table = table_;
 437         return &table[ix].oid;
 438 }
 439
 440 static const char *get_exact_ref_match(const struct object *o)
 441 {
 442         int found;
 443
 444         if (!tip_table.table || !tip_table.nr)
 445                 return NULL;
 446
 447         if (!tip_table.sorted) {
 448                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 449                 tip_table.sorted = 1;
 450         }
 451
 452         found = oid_pos(&o->oid, tip_table.table, tip_table.nr,
 453                         nth_tip_table_ent);
 454         if (0 <= found)
 455                 return tip_table.table[found].refname;
 456         return NULL;
 457 }
 458
 459 /* may return a constant string or use "buf" as scratch space */
 460 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 461 {
 462         struct rev_name *n;
 463         const struct commit *c;
 464
 465         if (o->type != OBJ_COMMIT)
 466                 return get_exact_ref_match(o);
 467         c = (const struct commit *) o;
 468         n = get_commit_rev_name(c);
 469         if (!n)
 470                 return NULL;
 471
 472         if (!n->generation)
 473                 return n->tip_name;
 474         else {
 475                 strbuf_reset(buf);
 476                 strbuf_addstr(buf, n->tip_name);
 477                 strbuf_strip_suffix(buf, "^0");
 478                 strbuf_addf(buf, "~%d", n->generation);
 479                 return buf->buf;
 480         }
 481 }
 482
 483 static void show_name(const struct object *obj,
 484                       const char *caller_name,
 485                       int always, int allow_undefined, int name_only)
 486 {
 487         const char *name;
 488         const struct object_id *oid = &obj->oid;
 489         struct strbuf buf = STRBUF_INIT;
 490
 491         if (!name_only)
 492                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 493         name = get_rev_name(obj, &buf);
 494         if (name)
 495                 printf("%s\n", name);
 496         else if (allow_undefined)
 497                 printf("undefined\n");
 498         else if (always)
 499                 printf("%s\n",
 500                        repo_find_unique_abbrev(the_repository, oid, DEFAULT_ABBREV));
 501         else
 502                 die("cannot describe '%s'", oid_to_hex(oid));
 503         strbuf_release(&buf);
 504 }
 505
 506 static char const * const name_rev_usage[] = {
 507         N_("git name-rev [<options>] <commit>..."),
 508         N_("git name-rev [<options>] --all"),
 509         N_("git name-rev [<options>] --annotate-stdin"),
 510         NULL
 511 };
 512
 513 static void name_rev_line(char *p, struct name_ref_data *data)
 514 {
 515         struct strbuf buf = STRBUF_INIT;
 516         int counter = 0;
 517         char *p_start;
 518         const unsigned hexsz = the_hash_algo->hexsz;
 519
 520         for (p_start = p; *p; p++) {
 521 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 522                 if (!ishex(*p))
 523                         counter = 0;
 524                 else if (++counter == hexsz &&
 525                          !ishex(*(p+1))) {
 526                         struct object_id oid;
 527                         const char *name = NULL;
 528                         char c = *(p+1);
 529                         int p_len = p - p_start + 1;
 530
 531                         counter = 0;
 532
 533                         *(p+1) = 0;
 534                         if (!repo_get_oid(the_repository, p - (hexsz - 1), &oid)) {
 535                                 struct object *o =
 536                                         lookup_object(the_repository, &oid);
 537                                 if (o)
 538                                         name = get_rev_name(o, &buf);
 539                         }
 540                         *(p+1) = c;
 541
 542                         if (!name)
 543                                 continue;
 544
 545                         if (data->name_only)
 546                                 printf("%.*s%s", p_len - hexsz, p_start, name);
 547                         else
 548                                 printf("%.*s (%s)", p_len, p_start, name);
 549                         p_start = p + 1;
 550                 }
 551         }
 552
 553         /* flush */
 554         if (p_start != p)
 555                 fwrite(p_start, p - p_start, 1, stdout);
 556
 557         strbuf_release(&buf);
 558 }
 559
 560 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 561 {
 562         struct mem_pool string_pool;
 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_F(0,
 576                            "stdin",
 577                            &transform_stdin,
 578                            N_("deprecated: use --annotate-stdin instead"),
 579                            PARSE_OPT_HIDDEN),
 580                 OPT_BOOL(0, "annotate-stdin", &annotate_stdin, N_("annotate text from stdin")),
 581                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 582                 OPT_BOOL(0, "always",     &always,
 583                            N_("show abbreviated commit object as fallback")),
 584                 OPT_HIDDEN_BOOL(0, "peel-tag", &peel_tag,
 585                            N_("dereference tags in the input (internal use)")),
 586                 OPT_END(),
 587         };
 588
 589         mem_pool_init(&string_pool, 0);
 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(&string_pool);
 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(string_pool);
 680         UNLEAK(revs);
 681         return 0;
 682 }