builtin/name-rev.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "repository.h"
   4 #include "config.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7 #include "refs.h"
   8 #include "parse-options.h"
   9 #include "prio-queue.h"
  10 #include "sha1-lookup.h"
  11 #include "commit-slab.h"
  12
  13 /*
  14  * One day.  See the 'name a rev shortly after epoch' test in t6120 when
  15  * changing this value
  16  */
  17 #define CUTOFF_DATE_SLOP 86400
  18
  19 typedef struct rev_name {
  20         const char *tip_name;
  21         timestamp_t taggerdate;
  22         int generation;
  23         int distance;
  24         int from_tag;
  25 } rev_name;
  26
  27 define_commit_slab(commit_rev_name, struct rev_name *);
  28
  29 static timestamp_t cutoff = TIME_MAX;
  30 static struct commit_rev_name rev_names;
  31
  32 /* How many generations are maximally preferred over _one_ merge traversal? */
  33 #define MERGE_TRAVERSAL_WEIGHT 65535
  34
  35 static struct rev_name *get_commit_rev_name(struct commit *commit)
  36 {
  37         struct rev_name **slot = commit_rev_name_peek(&rev_names, commit);
  38
  39         return slot ? *slot : NULL;
  40 }
  41
  42 static void set_commit_rev_name(struct commit *commit, struct rev_name *name)
  43 {
  44         *commit_rev_name_at(&rev_names, commit) = name;
  45 }
  46
  47 static int is_better_name(struct rev_name *name,
  48                           timestamp_t taggerdate,
  49                           int distance,
  50                           int from_tag)
  51 {
  52         /*
  53          * When comparing names based on tags, prefer names
  54          * based on the older tag, even if it is farther away.
  55          */
  56         if (from_tag && name->from_tag)
  57                 return (name->taggerdate > taggerdate ||
  58                         (name->taggerdate == taggerdate &&
  59                          name->distance > distance));
  60
  61         /*
  62          * We know that at least one of them is a non-tag at this point.
  63          * favor a tag over a non-tag.
  64          */
  65         if (name->from_tag != from_tag)
  66                 return from_tag;
  67
  68         /*
  69          * We are now looking at two non-tags.  Tiebreak to favor
  70          * shorter hops.
  71          */
  72         if (name->distance != distance)
  73                 return name->distance > distance;
  74
  75         /* ... or tiebreak to favor older date */
  76         if (name->taggerdate != taggerdate)
  77                 return name->taggerdate > taggerdate;
  78
  79         /* keep the current one if we cannot decide */
  80         return 0;
  81 }
  82
  83 static struct rev_name *create_or_update_name(struct commit *commit,
  84                                               const char *tip_name,
  85                                               timestamp_t taggerdate,
  86                                               int generation, int distance,
  87                                               int from_tag)
  88 {
  89         struct rev_name *name = get_commit_rev_name(commit);
  90
  91         if (name == NULL) {
  92                 name = xmalloc(sizeof(*name));
  93                 set_commit_rev_name(commit, name);
  94                 goto copy_data;
  95         } else if (is_better_name(name, taggerdate, distance, from_tag)) {
  96 copy_data:
  97                 name->tip_name = tip_name;
  98                 name->taggerdate = taggerdate;
  99                 name->generation = generation;
 100                 name->distance = distance;
 101                 name->from_tag = from_tag;
 102
 103                 return name;
 104         } else
 105                 return NULL;
 106 }
 107
 108 static void name_rev(struct commit *start_commit,
 109                 const char *tip_name, timestamp_t taggerdate,
 110                 int from_tag, int deref)
 111 {
 112         struct prio_queue queue;
 113         struct commit *commit;
 114         struct commit **parents_to_queue = NULL;
 115         size_t parents_to_queue_nr, parents_to_queue_alloc = 0;
 116         char *to_free = NULL;
 117
 118         parse_commit(start_commit);
 119         if (start_commit->date < cutoff)
 120                 return;
 121
 122         if (deref)
 123                 tip_name = to_free = xstrfmt("%s^0", tip_name);
 124
 125         if (!create_or_update_name(start_commit, tip_name, taggerdate, 0, 0,
 126                                    from_tag)) {
 127                 free(to_free);
 128                 return;
 129         }
 130
 131         memset(&queue, 0, sizeof(queue)); /* Use the prio_queue as LIFO */
 132         prio_queue_put(&queue, start_commit);
 133
 134         while ((commit = prio_queue_get(&queue))) {
 135                 struct rev_name *name = get_commit_rev_name(commit);
 136                 struct commit_list *parents;
 137                 int parent_number = 1;
 138
 139                 parents_to_queue_nr = 0;
 140
 141                 for (parents = commit->parents;
 142                                 parents;
 143                                 parents = parents->next, parent_number++) {
 144                         struct commit *parent = parents->item;
 145                         const char *new_name;
 146                         int generation, distance;
 147
 148                         parse_commit(parent);
 149                         if (parent->date < cutoff)
 150                                 continue;
 151
 152                         if (parent_number > 1) {
 153                                 size_t len;
 154
 155                                 strip_suffix(name->tip_name, "^0", &len);
 156                                 if (name->generation > 0)
 157                                         new_name = xstrfmt("%.*s~%d^%d",
 158                                                            (int)len,
 159                                                            name->tip_name,
 160                                                            name->generation,
 161                                                            parent_number);
 162                                 else
 163                                         new_name = xstrfmt("%.*s^%d", (int)len,
 164                                                            name->tip_name,
 165                                                            parent_number);
 166                                 generation = 0;
 167                                 distance = name->distance + MERGE_TRAVERSAL_WEIGHT;
 168                         } else {
 169                                 new_name = name->tip_name;
 170                                 generation = name->generation + 1;
 171                                 distance = name->distance + 1;
 172                         }
 173
 174                         if (create_or_update_name(parent, new_name, taggerdate,
 175                                                   generation, distance,
 176                                                   from_tag)) {
 177                                 ALLOC_GROW(parents_to_queue,
 178                                            parents_to_queue_nr + 1,
 179                                            parents_to_queue_alloc);
 180                                 parents_to_queue[parents_to_queue_nr] = parent;
 181                                 parents_to_queue_nr++;
 182                         }
 183                 }
 184
 185                 /* The first parent must come out first from the prio_queue */
 186                 while (parents_to_queue_nr)
 187                         prio_queue_put(&queue,
 188                                        parents_to_queue[--parents_to_queue_nr]);
 189         }
 190
 191         clear_prio_queue(&queue);
 192         free(parents_to_queue);
 193 }
 194
 195 static int subpath_matches(const char *path, const char *filter)
 196 {
 197         const char *subpath = path;
 198
 199         while (subpath) {
 200                 if (!wildmatch(filter, subpath, 0))
 201                         return subpath - path;
 202                 subpath = strchr(subpath, '/');
 203                 if (subpath)
 204                         subpath++;
 205         }
 206         return -1;
 207 }
 208
 209 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
 210 {
 211         if (shorten_unambiguous)
 212                 refname = shorten_unambiguous_ref(refname, 0);
 213         else if (skip_prefix(refname, "refs/heads/", &refname))
 214                 ; /* refname already advanced */
 215         else
 216                 skip_prefix(refname, "refs/", &refname);
 217         return refname;
 218 }
 219
 220 struct name_ref_data {
 221         int tags_only;
 222         int name_only;
 223         struct string_list ref_filters;
 224         struct string_list exclude_filters;
 225 };
 226
 227 static struct tip_table {
 228         struct tip_table_entry {
 229                 struct object_id oid;
 230                 const char *refname;
 231         } *table;
 232         int nr;
 233         int alloc;
 234         int sorted;
 235 } tip_table;
 236
 237 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 238                              int shorten_unambiguous)
 239 {
 240         refname = name_ref_abbrev(refname, shorten_unambiguous);
 241
 242         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 243         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 244         tip_table.table[tip_table.nr].refname = xstrdup(refname);
 245         tip_table.nr++;
 246         tip_table.sorted = 0;
 247 }
 248
 249 static int tipcmp(const void *a_, const void *b_)
 250 {
 251         const struct tip_table_entry *a = a_, *b = b_;
 252         return oidcmp(&a->oid, &b->oid);
 253 }
 254
 255 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
 256 {
 257         struct object *o = parse_object(the_repository, oid);
 258         struct name_ref_data *data = cb_data;
 259         int can_abbreviate_output = data->tags_only && data->name_only;
 260         int deref = 0;
 261         timestamp_t taggerdate = TIME_MAX;
 262
 263         if (data->tags_only && !starts_with(path, "refs/tags/"))
 264                 return 0;
 265
 266         if (data->exclude_filters.nr) {
 267                 struct string_list_item *item;
 268
 269                 for_each_string_list_item(item, &data->exclude_filters) {
 270                         if (subpath_matches(path, item->string) >= 0)
 271                                 return 0;
 272                 }
 273         }
 274
 275         if (data->ref_filters.nr) {
 276                 struct string_list_item *item;
 277                 int matched = 0;
 278
 279                 /* See if any of the patterns match. */
 280                 for_each_string_list_item(item, &data->ref_filters) {
 281                         /*
 282                          * Check all patterns even after finding a match, so
 283                          * that we can see if a match with a subpath exists.
 284                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 285                          * both of which match, the user is showing her
 286                          * willingness to accept a shortened output by having
 287                          * the 'v1.*' in the acceptable refnames, so we
 288                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 289                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 290                          */
 291                         switch (subpath_matches(path, item->string)) {
 292                         case -1: /* did not match */
 293                                 break;
 294                         case 0: /* matched fully */
 295                                 matched = 1;
 296                                 break;
 297                         default: /* matched subpath */
 298                                 matched = 1;
 299                                 can_abbreviate_output = 1;
 300                                 break;
 301                         }
 302                 }
 303
 304                 /* If none of the patterns matched, stop now */
 305                 if (!matched)
 306                         return 0;
 307         }
 308
 309         add_to_tip_table(oid, path, can_abbreviate_output);
 310
 311         while (o && o->type == OBJ_TAG) {
 312                 struct tag *t = (struct tag *) o;
 313                 if (!t->tagged)
 314                         break; /* broken repository */
 315                 o = parse_object(the_repository, &t->tagged->oid);
 316                 deref = 1;
 317                 taggerdate = t->date;
 318         }
 319         if (o && o->type == OBJ_COMMIT) {
 320                 struct commit *commit = (struct commit *)o;
 321                 int from_tag = starts_with(path, "refs/tags/");
 322
 323                 if (taggerdate == TIME_MAX)
 324                         taggerdate = commit->date;
 325                 path = name_ref_abbrev(path, can_abbreviate_output);
 326                 name_rev(commit, xstrdup(path), taggerdate, from_tag, deref);
 327         }
 328         return 0;
 329 }
 330
 331 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
 332 {
 333         struct tip_table_entry *table = table_;
 334         return table[ix].oid.hash;
 335 }
 336
 337 static const char *get_exact_ref_match(const struct object *o)
 338 {
 339         int found;
 340
 341         if (!tip_table.table || !tip_table.nr)
 342                 return NULL;
 343
 344         if (!tip_table.sorted) {
 345                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 346                 tip_table.sorted = 1;
 347         }
 348
 349         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
 350                          nth_tip_table_ent);
 351         if (0 <= found)
 352                 return tip_table.table[found].refname;
 353         return NULL;
 354 }
 355
 356 /* may return a constant string or use "buf" as scratch space */
 357 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 358 {
 359         struct rev_name *n;
 360         struct commit *c;
 361
 362         if (o->type != OBJ_COMMIT)
 363                 return get_exact_ref_match(o);
 364         c = (struct commit *) o;
 365         n = get_commit_rev_name(c);
 366         if (!n)
 367                 return NULL;
 368
 369         if (!n->generation)
 370                 return n->tip_name;
 371         else {
 372                 strbuf_reset(buf);
 373                 strbuf_addstr(buf, n->tip_name);
 374                 strbuf_strip_suffix(buf, "^0");
 375                 strbuf_addf(buf, "~%d", n->generation);
 376                 return buf->buf;
 377         }
 378 }
 379
 380 static void show_name(const struct object *obj,
 381                       const char *caller_name,
 382                       int always, int allow_undefined, int name_only)
 383 {
 384         const char *name;
 385         const struct object_id *oid = &obj->oid;
 386         struct strbuf buf = STRBUF_INIT;
 387
 388         if (!name_only)
 389                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 390         name = get_rev_name(obj, &buf);
 391         if (name)
 392                 printf("%s\n", name);
 393         else if (allow_undefined)
 394                 printf("undefined\n");
 395         else if (always)
 396                 printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV));
 397         else
 398                 die("cannot describe '%s'", oid_to_hex(oid));
 399         strbuf_release(&buf);
 400 }
 401
 402 static char const * const name_rev_usage[] = {
 403         N_("git name-rev [<options>] <commit>..."),
 404         N_("git name-rev [<options>] --all"),
 405         N_("git name-rev [<options>] --stdin"),
 406         NULL
 407 };
 408
 409 static void name_rev_line(char *p, struct name_ref_data *data)
 410 {
 411         struct strbuf buf = STRBUF_INIT;
 412         int counter = 0;
 413         char *p_start;
 414         const unsigned hexsz = the_hash_algo->hexsz;
 415
 416         for (p_start = p; *p; p++) {
 417 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 418                 if (!ishex(*p))
 419                         counter = 0;
 420                 else if (++counter == hexsz &&
 421                          !ishex(*(p+1))) {
 422                         struct object_id oid;
 423                         const char *name = NULL;
 424                         char c = *(p+1);
 425                         int p_len = p - p_start + 1;
 426
 427                         counter = 0;
 428
 429                         *(p+1) = 0;
 430                         if (!get_oid(p - (hexsz - 1), &oid)) {
 431                                 struct object *o =
 432                                         lookup_object(the_repository, &oid);
 433                                 if (o)
 434                                         name = get_rev_name(o, &buf);
 435                         }
 436                         *(p+1) = c;
 437
 438                         if (!name)
 439                                 continue;
 440
 441                         if (data->name_only)
 442                                 printf("%.*s%s", p_len - hexsz, p_start, name);
 443                         else
 444                                 printf("%.*s (%s)", p_len, p_start, name);
 445                         p_start = p + 1;
 446                 }
 447         }
 448
 449         /* flush */
 450         if (p_start != p)
 451                 fwrite(p_start, p - p_start, 1, stdout);
 452
 453         strbuf_release(&buf);
 454 }
 455
 456 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 457 {
 458         struct object_array revs = OBJECT_ARRAY_INIT;
 459         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 460         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 461         struct option opts[] = {
 462                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 463                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 464                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 465                                    N_("only use refs matching <pattern>")),
 466                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 467                                    N_("ignore refs matching <pattern>")),
 468                 OPT_GROUP(""),
 469                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 470                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
 471                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 472                 OPT_BOOL(0, "always",     &always,
 473                            N_("show abbreviated commit object as fallback")),
 474                 {
 475                         /* A Hidden OPT_BOOL */
 476                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 477                         N_("dereference tags in the input (internal use)"),
 478                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 479                 },
 480                 OPT_END(),
 481         };
 482
 483         init_commit_rev_name(&rev_names);
 484         git_config(git_default_config, NULL);
 485         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 486         if (all + transform_stdin + !!argc > 1) {
 487                 error("Specify either a list, or --all, not both!");
 488                 usage_with_options(name_rev_usage, opts);
 489         }
 490         if (all || transform_stdin)
 491                 cutoff = 0;
 492
 493         for (; argc; argc--, argv++) {
 494                 struct object_id oid;
 495                 struct object *object;
 496                 struct commit *commit;
 497
 498                 if (get_oid(*argv, &oid)) {
 499                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 500                                         *argv);
 501                         continue;
 502                 }
 503
 504                 commit = NULL;
 505                 object = parse_object(the_repository, &oid);
 506                 if (object) {
 507                         struct object *peeled = deref_tag(the_repository,
 508                                                           object, *argv, 0);
 509                         if (peeled && peeled->type == OBJ_COMMIT)
 510                                 commit = (struct commit *)peeled;
 511                 }
 512
 513                 if (!object) {
 514                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 515                                         *argv);
 516                         continue;
 517                 }
 518
 519                 if (commit) {
 520                         if (cutoff > commit->date)
 521                                 cutoff = commit->date;
 522                 }
 523
 524                 if (peel_tag) {
 525                         if (!commit) {
 526                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 527                                         *argv);
 528                                 continue;
 529                         }
 530                         object = (struct object *)commit;
 531                 }
 532                 add_object_array(object, *argv, &revs);
 533         }
 534
 535         if (cutoff) {
 536                 /* check for undeflow */
 537                 if (cutoff > TIME_MIN + CUTOFF_DATE_SLOP)
 538                         cutoff = cutoff - CUTOFF_DATE_SLOP;
 539                 else
 540                         cutoff = TIME_MIN;
 541         }
 542         for_each_ref(name_ref, &data);
 543
 544         if (transform_stdin) {
 545                 char buffer[2048];
 546
 547                 while (!feof(stdin)) {
 548                         char *p = fgets(buffer, sizeof(buffer), stdin);
 549                         if (!p)
 550                                 break;
 551                         name_rev_line(p, &data);
 552                 }
 553         } else if (all) {
 554                 int i, max;
 555
 556                 max = get_max_object_index();
 557                 for (i = 0; i < max; i++) {
 558                         struct object *obj = get_indexed_object(i);
 559                         if (!obj || obj->type != OBJ_COMMIT)
 560                                 continue;
 561                         show_name(obj, NULL,
 562                                   always, allow_undefined, data.name_only);
 563                 }
 564         } else {
 565                 int i;
 566                 for (i = 0; i < revs.nr; i++)
 567                         show_name(revs.objects[i].item, revs.objects[i].name,
 568                                   always, allow_undefined, data.name_only);
 569         }
 570
 571         UNLEAK(revs);
 572         return 0;
 573 }