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 #define CUTOFF_DATE_SLOP 86400 /* one day */
  13
  14 typedef struct rev_name {
  15         const char *tip_name;
  16         timestamp_t taggerdate;
  17         int generation;
  18         int distance;
  19         int from_tag;
  20 } rev_name;
  21
  22 define_commit_slab(commit_rev_name, struct rev_name *);
  23
  24 static timestamp_t cutoff = TIME_MAX;
  25 static struct commit_rev_name rev_names;
  26
  27 /* How many generations are maximally preferred over _one_ merge traversal? */
  28 #define MERGE_TRAVERSAL_WEIGHT 65535
  29
  30 static struct rev_name *get_commit_rev_name(struct commit *commit)
  31 {
  32         struct rev_name **slot = commit_rev_name_peek(&rev_names, commit);
  33
  34         return slot ? *slot : NULL;
  35 }
  36
  37 static void set_commit_rev_name(struct commit *commit, struct rev_name *name)
  38 {
  39         *commit_rev_name_at(&rev_names, commit) = name;
  40 }
  41
  42 static int is_better_name(struct rev_name *name,
  43                           const char *tip_name,
  44                           timestamp_t taggerdate,
  45                           int generation,
  46                           int distance,
  47                           int from_tag)
  48 {
  49         /*
  50          * When comparing names based on tags, prefer names
  51          * based on the older tag, even if it is farther away.
  52          */
  53         if (from_tag && name->from_tag)
  54                 return (name->taggerdate > taggerdate ||
  55                         (name->taggerdate == taggerdate &&
  56                          name->distance > distance));
  57
  58         /*
  59          * We know that at least one of them is a non-tag at this point.
  60          * favor a tag over a non-tag.
  61          */
  62         if (name->from_tag != from_tag)
  63                 return from_tag;
  64
  65         /*
  66          * We are now looking at two non-tags.  Tiebreak to favor
  67          * shorter hops.
  68          */
  69         if (name->distance != distance)
  70                 return name->distance > distance;
  71
  72         /* ... or tiebreak to favor older date */
  73         if (name->taggerdate != taggerdate)
  74                 return name->taggerdate > taggerdate;
  75
  76         /* keep the current one if we cannot decide */
  77         return 0;
  78 }
  79
  80 static void name_rev(struct commit *commit,
  81                 const char *tip_name, timestamp_t taggerdate,
  82                 int generation, int distance, int from_tag,
  83                 int deref)
  84 {
  85         struct rev_name *name = get_commit_rev_name(commit);
  86         struct commit_list *parents;
  87         int parent_number = 1;
  88         char *to_free = NULL;
  89
  90         parse_commit(commit);
  91
  92         if (commit->date < cutoff)
  93                 return;
  94
  95         if (deref) {
  96                 tip_name = to_free = xstrfmt("%s^0", tip_name);
  97
  98                 if (generation)
  99                         die("generation: %d, but deref?", generation);
 100         }
 101
 102         if (name == NULL) {
 103                 name = xmalloc(sizeof(rev_name));
 104                 set_commit_rev_name(commit, name);
 105                 goto copy_data;
 106         } else if (is_better_name(name, tip_name, taggerdate,
 107                                   generation, distance, from_tag)) {
 108 copy_data:
 109                 name->tip_name = tip_name;
 110                 name->taggerdate = taggerdate;
 111                 name->generation = generation;
 112                 name->distance = distance;
 113                 name->from_tag = from_tag;
 114         } else {
 115                 free(to_free);
 116                 return;
 117         }
 118
 119         for (parents = commit->parents;
 120                         parents;
 121                         parents = parents->next, parent_number++) {
 122                 if (parent_number > 1) {
 123                         size_t len;
 124                         char *new_name;
 125
 126                         strip_suffix(tip_name, "^0", &len);
 127                         if (generation > 0)
 128                                 new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
 129                                                    generation, parent_number);
 130                         else
 131                                 new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
 132                                                    parent_number);
 133
 134                         name_rev(parents->item, new_name, taggerdate, 0,
 135                                  distance + MERGE_TRAVERSAL_WEIGHT,
 136                                  from_tag, 0);
 137                 } else {
 138                         name_rev(parents->item, tip_name, taggerdate,
 139                                  generation + 1, distance + 1,
 140                                  from_tag, 0);
 141                 }
 142         }
 143 }
 144
 145 static int subpath_matches(const char *path, const char *filter)
 146 {
 147         const char *subpath = path;
 148
 149         while (subpath) {
 150                 if (!wildmatch(filter, subpath, 0))
 151                         return subpath - path;
 152                 subpath = strchr(subpath, '/');
 153                 if (subpath)
 154                         subpath++;
 155         }
 156         return -1;
 157 }
 158
 159 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
 160 {
 161         if (shorten_unambiguous)
 162                 refname = shorten_unambiguous_ref(refname, 0);
 163         else if (starts_with(refname, "refs/heads/"))
 164                 refname = refname + 11;
 165         else if (starts_with(refname, "refs/"))
 166                 refname = refname + 5;
 167         return refname;
 168 }
 169
 170 struct name_ref_data {
 171         int tags_only;
 172         int name_only;
 173         struct string_list ref_filters;
 174         struct string_list exclude_filters;
 175 };
 176
 177 static struct tip_table {
 178         struct tip_table_entry {
 179                 struct object_id oid;
 180                 const char *refname;
 181         } *table;
 182         int nr;
 183         int alloc;
 184         int sorted;
 185 } tip_table;
 186
 187 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 188                              int shorten_unambiguous)
 189 {
 190         refname = name_ref_abbrev(refname, shorten_unambiguous);
 191
 192         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 193         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 194         tip_table.table[tip_table.nr].refname = xstrdup(refname);
 195         tip_table.nr++;
 196         tip_table.sorted = 0;
 197 }
 198
 199 static int tipcmp(const void *a_, const void *b_)
 200 {
 201         const struct tip_table_entry *a = a_, *b = b_;
 202         return oidcmp(&a->oid, &b->oid);
 203 }
 204
 205 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
 206 {
 207         struct object *o = parse_object(the_repository, oid);
 208         struct name_ref_data *data = cb_data;
 209         int can_abbreviate_output = data->tags_only && data->name_only;
 210         int deref = 0;
 211         timestamp_t taggerdate = TIME_MAX;
 212
 213         if (data->tags_only && !starts_with(path, "refs/tags/"))
 214                 return 0;
 215
 216         if (data->exclude_filters.nr) {
 217                 struct string_list_item *item;
 218
 219                 for_each_string_list_item(item, &data->exclude_filters) {
 220                         if (subpath_matches(path, item->string) >= 0)
 221                                 return 0;
 222                 }
 223         }
 224
 225         if (data->ref_filters.nr) {
 226                 struct string_list_item *item;
 227                 int matched = 0;
 228
 229                 /* See if any of the patterns match. */
 230                 for_each_string_list_item(item, &data->ref_filters) {
 231                         /*
 232                          * Check all patterns even after finding a match, so
 233                          * that we can see if a match with a subpath exists.
 234                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 235                          * both of which match, the user is showing her
 236                          * willingness to accept a shortened output by having
 237                          * the 'v1.*' in the acceptable refnames, so we
 238                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 239                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 240                          */
 241                         switch (subpath_matches(path, item->string)) {
 242                         case -1: /* did not match */
 243                                 break;
 244                         case 0: /* matched fully */
 245                                 matched = 1;
 246                                 break;
 247                         default: /* matched subpath */
 248                                 matched = 1;
 249                                 can_abbreviate_output = 1;
 250                                 break;
 251                         }
 252                 }
 253
 254                 /* If none of the patterns matched, stop now */
 255                 if (!matched)
 256                         return 0;
 257         }
 258
 259         add_to_tip_table(oid, path, can_abbreviate_output);
 260
 261         while (o && o->type == OBJ_TAG) {
 262                 struct tag *t = (struct tag *) o;
 263                 if (!t->tagged)
 264                         break; /* broken repository */
 265                 o = parse_object(the_repository, &t->tagged->oid);
 266                 deref = 1;
 267                 taggerdate = t->date;
 268         }
 269         if (o && o->type == OBJ_COMMIT) {
 270                 struct commit *commit = (struct commit *)o;
 271                 int from_tag = starts_with(path, "refs/tags/");
 272
 273                 if (taggerdate == TIME_MAX)
 274                         taggerdate = ((struct commit *)o)->date;
 275                 path = name_ref_abbrev(path, can_abbreviate_output);
 276                 name_rev(commit, xstrdup(path), taggerdate, 0, 0,
 277                          from_tag, deref);
 278         }
 279         return 0;
 280 }
 281
 282 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
 283 {
 284         struct tip_table_entry *table = table_;
 285         return table[ix].oid.hash;
 286 }
 287
 288 static const char *get_exact_ref_match(const struct object *o)
 289 {
 290         int found;
 291
 292         if (!tip_table.table || !tip_table.nr)
 293                 return NULL;
 294
 295         if (!tip_table.sorted) {
 296                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 297                 tip_table.sorted = 1;
 298         }
 299
 300         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
 301                          nth_tip_table_ent);
 302         if (0 <= found)
 303                 return tip_table.table[found].refname;
 304         return NULL;
 305 }
 306
 307 /* may return a constant string or use "buf" as scratch space */
 308 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 309 {
 310         struct rev_name *n;
 311         struct commit *c;
 312
 313         if (o->type != OBJ_COMMIT)
 314                 return get_exact_ref_match(o);
 315         c = (struct commit *) o;
 316         n = get_commit_rev_name(c);
 317         if (!n)
 318                 return NULL;
 319
 320         if (!n->generation)
 321                 return n->tip_name;
 322         else {
 323                 int len = strlen(n->tip_name);
 324                 if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
 325                         len -= 2;
 326                 strbuf_reset(buf);
 327                 strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
 328                 return buf->buf;
 329         }
 330 }
 331
 332 static void show_name(const struct object *obj,
 333                       const char *caller_name,
 334                       int always, int allow_undefined, int name_only)
 335 {
 336         const char *name;
 337         const struct object_id *oid = &obj->oid;
 338         struct strbuf buf = STRBUF_INIT;
 339
 340         if (!name_only)
 341                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 342         name = get_rev_name(obj, &buf);
 343         if (name)
 344                 printf("%s\n", name);
 345         else if (allow_undefined)
 346                 printf("undefined\n");
 347         else if (always)
 348                 printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV));
 349         else
 350                 die("cannot describe '%s'", oid_to_hex(oid));
 351         strbuf_release(&buf);
 352 }
 353
 354 static char const * const name_rev_usage[] = {
 355         N_("git name-rev [<options>] <commit>..."),
 356         N_("git name-rev [<options>] --all"),
 357         N_("git name-rev [<options>] --stdin"),
 358         NULL
 359 };
 360
 361 static void name_rev_line(char *p, struct name_ref_data *data)
 362 {
 363         struct strbuf buf = STRBUF_INIT;
 364         int forty = 0;
 365         char *p_start;
 366         for (p_start = p; *p; p++) {
 367 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 368                 if (!ishex(*p))
 369                         forty = 0;
 370                 else if (++forty == GIT_SHA1_HEXSZ &&
 371                          !ishex(*(p+1))) {
 372                         struct object_id oid;
 373                         const char *name = NULL;
 374                         char c = *(p+1);
 375                         int p_len = p - p_start + 1;
 376
 377                         forty = 0;
 378
 379                         *(p+1) = 0;
 380                         if (!get_oid(p - (GIT_SHA1_HEXSZ - 1), &oid)) {
 381                                 struct object *o =
 382                                         lookup_object(the_repository,
 383                                                       oid.hash);
 384                                 if (o)
 385                                         name = get_rev_name(o, &buf);
 386                         }
 387                         *(p+1) = c;
 388
 389                         if (!name)
 390                                 continue;
 391
 392                         if (data->name_only)
 393                                 printf("%.*s%s", p_len - GIT_SHA1_HEXSZ, p_start, name);
 394                         else
 395                                 printf("%.*s (%s)", p_len, p_start, name);
 396                         p_start = p + 1;
 397                 }
 398         }
 399
 400         /* flush */
 401         if (p_start != p)
 402                 fwrite(p_start, p - p_start, 1, stdout);
 403
 404         strbuf_release(&buf);
 405 }
 406
 407 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 408 {
 409         struct object_array revs = OBJECT_ARRAY_INIT;
 410         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 411         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 412         struct option opts[] = {
 413                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 414                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 415                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 416                                    N_("only use refs matching <pattern>")),
 417                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 418                                    N_("ignore refs matching <pattern>")),
 419                 OPT_GROUP(""),
 420                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 421                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
 422                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 423                 OPT_BOOL(0, "always",     &always,
 424                            N_("show abbreviated commit object as fallback")),
 425                 {
 426                         /* A Hidden OPT_BOOL */
 427                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 428                         N_("dereference tags in the input (internal use)"),
 429                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 430                 },
 431                 OPT_END(),
 432         };
 433
 434         init_commit_rev_name(&rev_names);
 435         git_config(git_default_config, NULL);
 436         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 437         if (all + transform_stdin + !!argc > 1) {
 438                 error("Specify either a list, or --all, not both!");
 439                 usage_with_options(name_rev_usage, opts);
 440         }
 441         if (all || transform_stdin)
 442                 cutoff = 0;
 443
 444         for (; argc; argc--, argv++) {
 445                 struct object_id oid;
 446                 struct object *object;
 447                 struct commit *commit;
 448
 449                 if (get_oid(*argv, &oid)) {
 450                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 451                                         *argv);
 452                         continue;
 453                 }
 454
 455                 commit = NULL;
 456                 object = parse_object(the_repository, &oid);
 457                 if (object) {
 458                         struct object *peeled = deref_tag(the_repository,
 459                                                           object, *argv, 0);
 460                         if (peeled && peeled->type == OBJ_COMMIT)
 461                                 commit = (struct commit *)peeled;
 462                 }
 463
 464                 if (!object) {
 465                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 466                                         *argv);
 467                         continue;
 468                 }
 469
 470                 if (commit) {
 471                         if (cutoff > commit->date)
 472                                 cutoff = commit->date;
 473                 }
 474
 475                 if (peel_tag) {
 476                         if (!commit) {
 477                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 478                                         *argv);
 479                                 continue;
 480                         }
 481                         object = (struct object *)commit;
 482                 }
 483                 add_object_array(object, *argv, &revs);
 484         }
 485
 486         if (cutoff)
 487                 cutoff = cutoff - CUTOFF_DATE_SLOP;
 488         for_each_ref(name_ref, &data);
 489
 490         if (transform_stdin) {
 491                 char buffer[2048];
 492
 493                 while (!feof(stdin)) {
 494                         char *p = fgets(buffer, sizeof(buffer), stdin);
 495                         if (!p)
 496                                 break;
 497                         name_rev_line(p, &data);
 498                 }
 499         } else if (all) {
 500                 int i, max;
 501
 502                 max = get_max_object_index();
 503                 for (i = 0; i < max; i++) {
 504                         struct object *obj = get_indexed_object(i);
 505                         if (!obj || obj->type != OBJ_COMMIT)
 506                                 continue;
 507                         show_name(obj, NULL,
 508                                   always, allow_undefined, data.name_only);
 509                 }
 510         } else {
 511                 int i;
 512                 for (i = 0; i < revs.nr; i++)
 513                         show_name(revs.objects[i].item, revs.objects[i].name,
 514                                   always, allow_undefined, data.name_only);
 515         }
 516
 517         UNLEAK(revs);
 518         return 0;
 519 }