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