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 void name_rev(struct commit *commit,
  83                 const char *tip_name, timestamp_t taggerdate,
  84                 int generation, int distance, int from_tag,
  85                 int deref)
  86 {
  87         struct rev_name *name = get_commit_rev_name(commit);
  88         struct commit_list *parents;
  89         int parent_number = 1;
  90         char *to_free = NULL;
  91
  92         parse_commit(commit);
  93
  94         if (commit->date < cutoff)
  95                 return;
  96
  97         if (deref) {
  98                 tip_name = to_free = xstrfmt("%s^0", tip_name);
  99
 100                 if (generation)
 101                         die("generation: %d, but deref?", generation);
 102         }
 103
 104         if (name == NULL) {
 105                 name = xmalloc(sizeof(rev_name));
 106                 set_commit_rev_name(commit, name);
 107                 goto copy_data;
 108         } else if (is_better_name(name, taggerdate, distance, from_tag)) {
 109 copy_data:
 110                 name->tip_name = tip_name;
 111                 name->taggerdate = taggerdate;
 112                 name->generation = generation;
 113                 name->distance = distance;
 114                 name->from_tag = from_tag;
 115         } else {
 116                 free(to_free);
 117                 return;
 118         }
 119
 120         for (parents = commit->parents;
 121                         parents;
 122                         parents = parents->next, parent_number++) {
 123                 if (parent_number > 1) {
 124                         size_t len;
 125                         char *new_name;
 126
 127                         strip_suffix(tip_name, "^0", &len);
 128                         if (generation > 0)
 129                                 new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
 130                                                    generation, parent_number);
 131                         else
 132                                 new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
 133                                                    parent_number);
 134
 135                         name_rev(parents->item, new_name, taggerdate, 0,
 136                                  distance + MERGE_TRAVERSAL_WEIGHT,
 137                                  from_tag, 0);
 138                 } else {
 139                         name_rev(parents->item, tip_name, taggerdate,
 140                                  generation + 1, distance + 1,
 141                                  from_tag, 0);
 142                 }
 143         }
 144 }
 145
 146 static int subpath_matches(const char *path, const char *filter)
 147 {
 148         const char *subpath = path;
 149
 150         while (subpath) {
 151                 if (!wildmatch(filter, subpath, 0))
 152                         return subpath - path;
 153                 subpath = strchr(subpath, '/');
 154                 if (subpath)
 155                         subpath++;
 156         }
 157         return -1;
 158 }
 159
 160 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
 161 {
 162         if (shorten_unambiguous)
 163                 refname = shorten_unambiguous_ref(refname, 0);
 164         else if (starts_with(refname, "refs/heads/"))
 165                 refname = refname + 11;
 166         else if (starts_with(refname, "refs/"))
 167                 refname = refname + 5;
 168         return refname;
 169 }
 170
 171 struct name_ref_data {
 172         int tags_only;
 173         int name_only;
 174         struct string_list ref_filters;
 175         struct string_list exclude_filters;
 176 };
 177
 178 static struct tip_table {
 179         struct tip_table_entry {
 180                 struct object_id oid;
 181                 const char *refname;
 182         } *table;
 183         int nr;
 184         int alloc;
 185         int sorted;
 186 } tip_table;
 187
 188 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 189                              int shorten_unambiguous)
 190 {
 191         refname = name_ref_abbrev(refname, shorten_unambiguous);
 192
 193         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 194         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 195         tip_table.table[tip_table.nr].refname = xstrdup(refname);
 196         tip_table.nr++;
 197         tip_table.sorted = 0;
 198 }
 199
 200 static int tipcmp(const void *a_, const void *b_)
 201 {
 202         const struct tip_table_entry *a = a_, *b = b_;
 203         return oidcmp(&a->oid, &b->oid);
 204 }
 205
 206 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
 207 {
 208         struct object *o = parse_object(the_repository, oid);
 209         struct name_ref_data *data = cb_data;
 210         int can_abbreviate_output = data->tags_only && data->name_only;
 211         int deref = 0;
 212         timestamp_t taggerdate = TIME_MAX;
 213
 214         if (data->tags_only && !starts_with(path, "refs/tags/"))
 215                 return 0;
 216
 217         if (data->exclude_filters.nr) {
 218                 struct string_list_item *item;
 219
 220                 for_each_string_list_item(item, &data->exclude_filters) {
 221                         if (subpath_matches(path, item->string) >= 0)
 222                                 return 0;
 223                 }
 224         }
 225
 226         if (data->ref_filters.nr) {
 227                 struct string_list_item *item;
 228                 int matched = 0;
 229
 230                 /* See if any of the patterns match. */
 231                 for_each_string_list_item(item, &data->ref_filters) {
 232                         /*
 233                          * Check all patterns even after finding a match, so
 234                          * that we can see if a match with a subpath exists.
 235                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 236                          * both of which match, the user is showing her
 237                          * willingness to accept a shortened output by having
 238                          * the 'v1.*' in the acceptable refnames, so we
 239                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 240                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 241                          */
 242                         switch (subpath_matches(path, item->string)) {
 243                         case -1: /* did not match */
 244                                 break;
 245                         case 0: /* matched fully */
 246                                 matched = 1;
 247                                 break;
 248                         default: /* matched subpath */
 249                                 matched = 1;
 250                                 can_abbreviate_output = 1;
 251                                 break;
 252                         }
 253                 }
 254
 255                 /* If none of the patterns matched, stop now */
 256                 if (!matched)
 257                         return 0;
 258         }
 259
 260         add_to_tip_table(oid, path, can_abbreviate_output);
 261
 262         while (o && o->type == OBJ_TAG) {
 263                 struct tag *t = (struct tag *) o;
 264                 if (!t->tagged)
 265                         break; /* broken repository */
 266                 o = parse_object(the_repository, &t->tagged->oid);
 267                 deref = 1;
 268                 taggerdate = t->date;
 269         }
 270         if (o && o->type == OBJ_COMMIT) {
 271                 struct commit *commit = (struct commit *)o;
 272                 int from_tag = starts_with(path, "refs/tags/");
 273
 274                 if (taggerdate == TIME_MAX)
 275                         taggerdate = ((struct commit *)o)->date;
 276                 path = name_ref_abbrev(path, can_abbreviate_output);
 277                 name_rev(commit, xstrdup(path), taggerdate, 0, 0,
 278                          from_tag, deref);
 279         }
 280         return 0;
 281 }
 282
 283 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
 284 {
 285         struct tip_table_entry *table = table_;
 286         return table[ix].oid.hash;
 287 }
 288
 289 static const char *get_exact_ref_match(const struct object *o)
 290 {
 291         int found;
 292
 293         if (!tip_table.table || !tip_table.nr)
 294                 return NULL;
 295
 296         if (!tip_table.sorted) {
 297                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 298                 tip_table.sorted = 1;
 299         }
 300
 301         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
 302                          nth_tip_table_ent);
 303         if (0 <= found)
 304                 return tip_table.table[found].refname;
 305         return NULL;
 306 }
 307
 308 /* may return a constant string or use "buf" as scratch space */
 309 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 310 {
 311         struct rev_name *n;
 312         struct commit *c;
 313
 314         if (o->type != OBJ_COMMIT)
 315                 return get_exact_ref_match(o);
 316         c = (struct commit *) o;
 317         n = get_commit_rev_name(c);
 318         if (!n)
 319                 return NULL;
 320
 321         if (!n->generation)
 322                 return n->tip_name;
 323         else {
 324                 int len = strlen(n->tip_name);
 325                 if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
 326                         len -= 2;
 327                 strbuf_reset(buf);
 328                 strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
 329                 return buf->buf;
 330         }
 331 }
 332
 333 static void show_name(const struct object *obj,
 334                       const char *caller_name,
 335                       int always, int allow_undefined, int name_only)
 336 {
 337         const char *name;
 338         const struct object_id *oid = &obj->oid;
 339         struct strbuf buf = STRBUF_INIT;
 340
 341         if (!name_only)
 342                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 343         name = get_rev_name(obj, &buf);
 344         if (name)
 345                 printf("%s\n", name);
 346         else if (allow_undefined)
 347                 printf("undefined\n");
 348         else if (always)
 349                 printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV));
 350         else
 351                 die("cannot describe '%s'", oid_to_hex(oid));
 352         strbuf_release(&buf);
 353 }
 354
 355 static char const * const name_rev_usage[] = {
 356         N_("git name-rev [<options>] <commit>..."),
 357         N_("git name-rev [<options>] --all"),
 358         N_("git name-rev [<options>] --stdin"),
 359         NULL
 360 };
 361
 362 static void name_rev_line(char *p, struct name_ref_data *data)
 363 {
 364         struct strbuf buf = STRBUF_INIT;
 365         int counter = 0;
 366         char *p_start;
 367         const unsigned hexsz = the_hash_algo->hexsz;
 368
 369         for (p_start = p; *p; p++) {
 370 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 371                 if (!ishex(*p))
 372                         counter = 0;
 373                 else if (++counter == hexsz &&
 374                          !ishex(*(p+1))) {
 375                         struct object_id oid;
 376                         const char *name = NULL;
 377                         char c = *(p+1);
 378                         int p_len = p - p_start + 1;
 379
 380                         counter = 0;
 381
 382                         *(p+1) = 0;
 383                         if (!get_oid(p - (hexsz - 1), &oid)) {
 384                                 struct object *o =
 385                                         lookup_object(the_repository, &oid);
 386                                 if (o)
 387                                         name = get_rev_name(o, &buf);
 388                         }
 389                         *(p+1) = c;
 390
 391                         if (!name)
 392                                 continue;
 393
 394                         if (data->name_only)
 395                                 printf("%.*s%s", p_len - hexsz, p_start, name);
 396                         else
 397                                 printf("%.*s (%s)", p_len, p_start, name);
 398                         p_start = p + 1;
 399                 }
 400         }
 401
 402         /* flush */
 403         if (p_start != p)
 404                 fwrite(p_start, p - p_start, 1, stdout);
 405
 406         strbuf_release(&buf);
 407 }
 408
 409 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 410 {
 411         struct object_array revs = OBJECT_ARRAY_INIT;
 412         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 413         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 414         struct option opts[] = {
 415                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 416                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 417                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 418                                    N_("only use refs matching <pattern>")),
 419                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 420                                    N_("ignore refs matching <pattern>")),
 421                 OPT_GROUP(""),
 422                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 423                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
 424                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 425                 OPT_BOOL(0, "always",     &always,
 426                            N_("show abbreviated commit object as fallback")),
 427                 {
 428                         /* A Hidden OPT_BOOL */
 429                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 430                         N_("dereference tags in the input (internal use)"),
 431                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 432                 },
 433                 OPT_END(),
 434         };
 435
 436         init_commit_rev_name(&rev_names);
 437         git_config(git_default_config, NULL);
 438         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 439         if (all + transform_stdin + !!argc > 1) {
 440                 error("Specify either a list, or --all, not both!");
 441                 usage_with_options(name_rev_usage, opts);
 442         }
 443         if (all || transform_stdin)
 444                 cutoff = 0;
 445
 446         for (; argc; argc--, argv++) {
 447                 struct object_id oid;
 448                 struct object *object;
 449                 struct commit *commit;
 450
 451                 if (get_oid(*argv, &oid)) {
 452                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 453                                         *argv);
 454                         continue;
 455                 }
 456
 457                 commit = NULL;
 458                 object = parse_object(the_repository, &oid);
 459                 if (object) {
 460                         struct object *peeled = deref_tag(the_repository,
 461                                                           object, *argv, 0);
 462                         if (peeled && peeled->type == OBJ_COMMIT)
 463                                 commit = (struct commit *)peeled;
 464                 }
 465
 466                 if (!object) {
 467                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 468                                         *argv);
 469                         continue;
 470                 }
 471
 472                 if (commit) {
 473                         if (cutoff > commit->date)
 474                                 cutoff = commit->date;
 475                 }
 476
 477                 if (peel_tag) {
 478                         if (!commit) {
 479                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 480                                         *argv);
 481                                 continue;
 482                         }
 483                         object = (struct object *)commit;
 484                 }
 485                 add_object_array(object, *argv, &revs);
 486         }
 487
 488         if (cutoff) {
 489                 /* check for undeflow */
 490                 if (cutoff > TIME_MIN + CUTOFF_DATE_SLOP)
 491                         cutoff = cutoff - CUTOFF_DATE_SLOP;
 492                 else
 493                         cutoff = TIME_MIN;
 494         }
 495         for_each_ref(name_ref, &data);
 496
 497         if (transform_stdin) {
 498                 char buffer[2048];
 499
 500                 while (!feof(stdin)) {
 501                         char *p = fgets(buffer, sizeof(buffer), stdin);
 502                         if (!p)
 503                                 break;
 504                         name_rev_line(p, &data);
 505                 }
 506         } else if (all) {
 507                 int i, max;
 508
 509                 max = get_max_object_index();
 510                 for (i = 0; i < max; i++) {
 511                         struct object *obj = get_indexed_object(i);
 512                         if (!obj || obj->type != OBJ_COMMIT)
 513                                 continue;
 514                         show_name(obj, NULL,
 515                                   always, allow_undefined, data.name_only);
 516                 }
 517         } else {
 518                 int i;
 519                 for (i = 0; i < revs.nr; i++)
 520                         show_name(revs.objects[i].item, revs.objects[i].name,
 521                                   always, allow_undefined, data.name_only);
 522         }
 523
 524         UNLEAK(revs);
 525         return 0;
 526 }