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 struct rev_name {
  20         const char *tip_name;
  21         timestamp_t taggerdate;
  22         int generation;
  23         int distance;
  24         int from_tag;
  25 };
  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(const 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 && !is_better_name(name, taggerdate, distance, from_tag))
  92                 return NULL;
  93
  94         if (name == NULL) {
  95                 name = xmalloc(sizeof(*name));
  96                 set_commit_rev_name(commit, name);
  97         }
  98
  99         name->tip_name = tip_name;
 100         name->taggerdate = taggerdate;
 101         name->generation = generation;
 102         name->distance = distance;
 103         name->from_tag = from_tag;
 104
 105         return name;
 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         else
 125                 tip_name = to_free = xstrdup(tip_name);
 126
 127         if (!create_or_update_name(start_commit, tip_name, taggerdate, 0, 0,
 128                                    from_tag)) {
 129                 free(to_free);
 130                 return;
 131         }
 132
 133         memset(&queue, 0, sizeof(queue)); /* Use the prio_queue as LIFO */
 134         prio_queue_put(&queue, start_commit);
 135
 136         while ((commit = prio_queue_get(&queue))) {
 137                 struct rev_name *name = get_commit_rev_name(commit);
 138                 struct commit_list *parents;
 139                 int parent_number = 1;
 140
 141                 parents_to_queue_nr = 0;
 142
 143                 for (parents = commit->parents;
 144                                 parents;
 145                                 parents = parents->next, parent_number++) {
 146                         struct commit *parent = parents->item;
 147                         const char *new_name;
 148                         int generation, distance;
 149
 150                         parse_commit(parent);
 151                         if (parent->date < cutoff)
 152                                 continue;
 153
 154                         if (parent_number > 1) {
 155                                 size_t len;
 156
 157                                 strip_suffix(name->tip_name, "^0", &len);
 158                                 if (name->generation > 0)
 159                                         new_name = xstrfmt("%.*s~%d^%d",
 160                                                            (int)len,
 161                                                            name->tip_name,
 162                                                            name->generation,
 163                                                            parent_number);
 164                                 else
 165                                         new_name = xstrfmt("%.*s^%d", (int)len,
 166                                                            name->tip_name,
 167                                                            parent_number);
 168                                 generation = 0;
 169                                 distance = name->distance + MERGE_TRAVERSAL_WEIGHT;
 170                         } else {
 171                                 new_name = name->tip_name;
 172                                 generation = name->generation + 1;
 173                                 distance = name->distance + 1;
 174                         }
 175
 176                         if (create_or_update_name(parent, new_name, taggerdate,
 177                                                   generation, distance,
 178                                                   from_tag)) {
 179                                 ALLOC_GROW(parents_to_queue,
 180                                            parents_to_queue_nr + 1,
 181                                            parents_to_queue_alloc);
 182                                 parents_to_queue[parents_to_queue_nr] = parent;
 183                                 parents_to_queue_nr++;
 184                         }
 185                 }
 186
 187                 /* The first parent must come out first from the prio_queue */
 188                 while (parents_to_queue_nr)
 189                         prio_queue_put(&queue,
 190                                        parents_to_queue[--parents_to_queue_nr]);
 191         }
 192
 193         clear_prio_queue(&queue);
 194         free(parents_to_queue);
 195 }
 196
 197 static int subpath_matches(const char *path, const char *filter)
 198 {
 199         const char *subpath = path;
 200
 201         while (subpath) {
 202                 if (!wildmatch(filter, subpath, 0))
 203                         return subpath - path;
 204                 subpath = strchr(subpath, '/');
 205                 if (subpath)
 206                         subpath++;
 207         }
 208         return -1;
 209 }
 210
 211 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
 212 {
 213         if (shorten_unambiguous)
 214                 refname = shorten_unambiguous_ref(refname, 0);
 215         else if (skip_prefix(refname, "refs/heads/", &refname))
 216                 ; /* refname already advanced */
 217         else
 218                 skip_prefix(refname, "refs/", &refname);
 219         return refname;
 220 }
 221
 222 struct name_ref_data {
 223         int tags_only;
 224         int name_only;
 225         struct string_list ref_filters;
 226         struct string_list exclude_filters;
 227 };
 228
 229 static struct tip_table {
 230         struct tip_table_entry {
 231                 struct object_id oid;
 232                 const char *refname;
 233         } *table;
 234         int nr;
 235         int alloc;
 236         int sorted;
 237 } tip_table;
 238
 239 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 240                              int shorten_unambiguous)
 241 {
 242         refname = name_ref_abbrev(refname, shorten_unambiguous);
 243
 244         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 245         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 246         tip_table.table[tip_table.nr].refname = xstrdup(refname);
 247         tip_table.nr++;
 248         tip_table.sorted = 0;
 249 }
 250
 251 static int tipcmp(const void *a_, const void *b_)
 252 {
 253         const struct tip_table_entry *a = a_, *b = b_;
 254         return oidcmp(&a->oid, &b->oid);
 255 }
 256
 257 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
 258 {
 259         struct object *o = parse_object(the_repository, oid);
 260         struct name_ref_data *data = cb_data;
 261         int can_abbreviate_output = data->tags_only && data->name_only;
 262         int deref = 0;
 263         timestamp_t taggerdate = TIME_MAX;
 264
 265         if (data->tags_only && !starts_with(path, "refs/tags/"))
 266                 return 0;
 267
 268         if (data->exclude_filters.nr) {
 269                 struct string_list_item *item;
 270
 271                 for_each_string_list_item(item, &data->exclude_filters) {
 272                         if (subpath_matches(path, item->string) >= 0)
 273                                 return 0;
 274                 }
 275         }
 276
 277         if (data->ref_filters.nr) {
 278                 struct string_list_item *item;
 279                 int matched = 0;
 280
 281                 /* See if any of the patterns match. */
 282                 for_each_string_list_item(item, &data->ref_filters) {
 283                         /*
 284                          * Check all patterns even after finding a match, so
 285                          * that we can see if a match with a subpath exists.
 286                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 287                          * both of which match, the user is showing her
 288                          * willingness to accept a shortened output by having
 289                          * the 'v1.*' in the acceptable refnames, so we
 290                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 291                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 292                          */
 293                         switch (subpath_matches(path, item->string)) {
 294                         case -1: /* did not match */
 295                                 break;
 296                         case 0: /* matched fully */
 297                                 matched = 1;
 298                                 break;
 299                         default: /* matched subpath */
 300                                 matched = 1;
 301                                 can_abbreviate_output = 1;
 302                                 break;
 303                         }
 304                 }
 305
 306                 /* If none of the patterns matched, stop now */
 307                 if (!matched)
 308                         return 0;
 309         }
 310
 311         add_to_tip_table(oid, path, can_abbreviate_output);
 312
 313         while (o && o->type == OBJ_TAG) {
 314                 struct tag *t = (struct tag *) o;
 315                 if (!t->tagged)
 316                         break; /* broken repository */
 317                 o = parse_object(the_repository, &t->tagged->oid);
 318                 deref = 1;
 319                 taggerdate = t->date;
 320         }
 321         if (o && o->type == OBJ_COMMIT) {
 322                 struct commit *commit = (struct commit *)o;
 323                 int from_tag = starts_with(path, "refs/tags/");
 324
 325                 if (taggerdate == TIME_MAX)
 326                         taggerdate = commit->date;
 327                 path = name_ref_abbrev(path, can_abbreviate_output);
 328                 name_rev(commit, path, taggerdate, from_tag, deref);
 329         }
 330         return 0;
 331 }
 332
 333 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
 334 {
 335         struct tip_table_entry *table = table_;
 336         return table[ix].oid.hash;
 337 }
 338
 339 static const char *get_exact_ref_match(const struct object *o)
 340 {
 341         int found;
 342
 343         if (!tip_table.table || !tip_table.nr)
 344                 return NULL;
 345
 346         if (!tip_table.sorted) {
 347                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 348                 tip_table.sorted = 1;
 349         }
 350
 351         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
 352                          nth_tip_table_ent);
 353         if (0 <= found)
 354                 return tip_table.table[found].refname;
 355         return NULL;
 356 }
 357
 358 /* may return a constant string or use "buf" as scratch space */
 359 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 360 {
 361         struct rev_name *n;
 362         const struct commit *c;
 363
 364         if (o->type != OBJ_COMMIT)
 365                 return get_exact_ref_match(o);
 366         c = (const struct commit *) o;
 367         n = get_commit_rev_name(c);
 368         if (!n)
 369                 return NULL;
 370
 371         if (!n->generation)
 372                 return n->tip_name;
 373         else {
 374                 strbuf_reset(buf);
 375                 strbuf_addstr(buf, n->tip_name);
 376                 strbuf_strip_suffix(buf, "^0");
 377                 strbuf_addf(buf, "~%d", n->generation);
 378                 return buf->buf;
 379         }
 380 }
 381
 382 static void show_name(const struct object *obj,
 383                       const char *caller_name,
 384                       int always, int allow_undefined, int name_only)
 385 {
 386         const char *name;
 387         const struct object_id *oid = &obj->oid;
 388         struct strbuf buf = STRBUF_INIT;
 389
 390         if (!name_only)
 391                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 392         name = get_rev_name(obj, &buf);
 393         if (name)
 394                 printf("%s\n", name);
 395         else if (allow_undefined)
 396                 printf("undefined\n");
 397         else if (always)
 398                 printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV));
 399         else
 400                 die("cannot describe '%s'", oid_to_hex(oid));
 401         strbuf_release(&buf);
 402 }
 403
 404 static char const * const name_rev_usage[] = {
 405         N_("git name-rev [<options>] <commit>..."),
 406         N_("git name-rev [<options>] --all"),
 407         N_("git name-rev [<options>] --stdin"),
 408         NULL
 409 };
 410
 411 static void name_rev_line(char *p, struct name_ref_data *data)
 412 {
 413         struct strbuf buf = STRBUF_INIT;
 414         int counter = 0;
 415         char *p_start;
 416         const unsigned hexsz = the_hash_algo->hexsz;
 417
 418         for (p_start = p; *p; p++) {
 419 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 420                 if (!ishex(*p))
 421                         counter = 0;
 422                 else if (++counter == hexsz &&
 423                          !ishex(*(p+1))) {
 424                         struct object_id oid;
 425                         const char *name = NULL;
 426                         char c = *(p+1);
 427                         int p_len = p - p_start + 1;
 428
 429                         counter = 0;
 430
 431                         *(p+1) = 0;
 432                         if (!get_oid(p - (hexsz - 1), &oid)) {
 433                                 struct object *o =
 434                                         lookup_object(the_repository, &oid);
 435                                 if (o)
 436                                         name = get_rev_name(o, &buf);
 437                         }
 438                         *(p+1) = c;
 439
 440                         if (!name)
 441                                 continue;
 442
 443                         if (data->name_only)
 444                                 printf("%.*s%s", p_len - hexsz, p_start, name);
 445                         else
 446                                 printf("%.*s (%s)", p_len, p_start, name);
 447                         p_start = p + 1;
 448                 }
 449         }
 450
 451         /* flush */
 452         if (p_start != p)
 453                 fwrite(p_start, p - p_start, 1, stdout);
 454
 455         strbuf_release(&buf);
 456 }
 457
 458 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 459 {
 460         struct object_array revs = OBJECT_ARRAY_INIT;
 461         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 462         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 463         struct option opts[] = {
 464                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 465                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 466                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 467                                    N_("only use refs matching <pattern>")),
 468                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 469                                    N_("ignore refs matching <pattern>")),
 470                 OPT_GROUP(""),
 471                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 472                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
 473                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 474                 OPT_BOOL(0, "always",     &always,
 475                            N_("show abbreviated commit object as fallback")),
 476                 {
 477                         /* A Hidden OPT_BOOL */
 478                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 479                         N_("dereference tags in the input (internal use)"),
 480                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 481                 },
 482                 OPT_END(),
 483         };
 484
 485         init_commit_rev_name(&rev_names);
 486         git_config(git_default_config, NULL);
 487         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 488         if (all + transform_stdin + !!argc > 1) {
 489                 error("Specify either a list, or --all, not both!");
 490                 usage_with_options(name_rev_usage, opts);
 491         }
 492         if (all || transform_stdin)
 493                 cutoff = 0;
 494
 495         for (; argc; argc--, argv++) {
 496                 struct object_id oid;
 497                 struct object *object;
 498                 struct commit *commit;
 499
 500                 if (get_oid(*argv, &oid)) {
 501                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 502                                         *argv);
 503                         continue;
 504                 }
 505
 506                 commit = NULL;
 507                 object = parse_object(the_repository, &oid);
 508                 if (object) {
 509                         struct object *peeled = deref_tag(the_repository,
 510                                                           object, *argv, 0);
 511                         if (peeled && peeled->type == OBJ_COMMIT)
 512                                 commit = (struct commit *)peeled;
 513                 }
 514
 515                 if (!object) {
 516                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 517                                         *argv);
 518                         continue;
 519                 }
 520
 521                 if (commit) {
 522                         if (cutoff > commit->date)
 523                                 cutoff = commit->date;
 524                 }
 525
 526                 if (peel_tag) {
 527                         if (!commit) {
 528                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 529                                         *argv);
 530                                 continue;
 531                         }
 532                         object = (struct object *)commit;
 533                 }
 534                 add_object_array(object, *argv, &revs);
 535         }
 536
 537         if (cutoff) {
 538                 /* check for undeflow */
 539                 if (cutoff > TIME_MIN + CUTOFF_DATE_SLOP)
 540                         cutoff = cutoff - CUTOFF_DATE_SLOP;
 541                 else
 542                         cutoff = TIME_MIN;
 543         }
 544         for_each_ref(name_ref, &data);
 545
 546         if (transform_stdin) {
 547                 char buffer[2048];
 548
 549                 while (!feof(stdin)) {
 550                         char *p = fgets(buffer, sizeof(buffer), stdin);
 551                         if (!p)
 552                                 break;
 553                         name_rev_line(p, &data);
 554                 }
 555         } else if (all) {
 556                 int i, max;
 557
 558                 max = get_max_object_index();
 559                 for (i = 0; i < max; i++) {
 560                         struct object *obj = get_indexed_object(i);
 561                         if (!obj || obj->type != OBJ_COMMIT)
 562                                 continue;
 563                         show_name(obj, NULL,
 564                                   always, allow_undefined, data.name_only);
 565                 }
 566         } else {
 567                 int i;
 568                 for (i = 0; i < revs.nr; i++)
 569                         show_name(revs.objects[i].item, revs.objects[i].name,
 570                                   always, allow_undefined, data.name_only);
 571         }
 572
 573         UNLEAK(revs);
 574         return 0;
 575 }