builtin/name-rev.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "config.h"
   4 #include "commit.h"
   5 #include "tag.h"
   6 #include "refs.h"
   7 #include "parse-options.h"
   8 #include "sha1-lookup.h"
   9
  10 #define CUTOFF_DATE_SLOP 86400 /* one day */
  11
  12 typedef struct rev_name {
  13         const char *tip_name;
  14         timestamp_t taggerdate;
  15         int generation;
  16         int distance;
  17         int from_tag;
  18 } rev_name;
  19
  20 static timestamp_t cutoff = TIME_MAX;
  21
  22 /* How many generations are maximally preferred over _one_ merge traversal? */
  23 #define MERGE_TRAVERSAL_WEIGHT 65535
  24
  25 static int is_better_name(struct rev_name *name,
  26                           const char *tip_name,
  27                           timestamp_t taggerdate,
  28                           int generation,
  29                           int distance,
  30                           int from_tag)
  31 {
  32         /*
  33          * When comparing names based on tags, prefer names
  34          * based on the older tag, even if it is farther away.
  35          */
  36         if (from_tag && name->from_tag)
  37                 return (name->taggerdate > taggerdate ||
  38                         (name->taggerdate == taggerdate &&
  39                          name->distance > distance));
  40
  41         /*
  42          * We know that at least one of them is a non-tag at this point.
  43          * favor a tag over a non-tag.
  44          */
  45         if (name->from_tag != from_tag)
  46                 return from_tag;
  47
  48         /*
  49          * We are now looking at two non-tags.  Tiebreak to favor
  50          * shorter hops.
  51          */
  52         if (name->distance != distance)
  53                 return name->distance > distance;
  54
  55         /* ... or tiebreak to favor older date */
  56         if (name->taggerdate != taggerdate)
  57                 return name->taggerdate > taggerdate;
  58
  59         /* keep the current one if we cannot decide */
  60         return 0;
  61 }
  62
  63 static void name_rev(struct commit *commit,
  64                 const char *tip_name, timestamp_t taggerdate,
  65                 int generation, int distance, int from_tag,
  66                 int deref)
  67 {
  68         struct rev_name *name = (struct rev_name *)commit->util;
  69         struct commit_list *parents;
  70         int parent_number = 1;
  71         char *to_free = NULL;
  72
  73         parse_commit(commit);
  74
  75         if (commit->date < cutoff)
  76                 return;
  77
  78         if (deref) {
  79                 tip_name = to_free = xstrfmt("%s^0", tip_name);
  80
  81                 if (generation)
  82                         die("generation: %d, but deref?", generation);
  83         }
  84
  85         if (name == NULL) {
  86                 name = xmalloc(sizeof(rev_name));
  87                 commit->util = name;
  88                 goto copy_data;
  89         } else if (is_better_name(name, tip_name, taggerdate,
  90                                   generation, distance, from_tag)) {
  91 copy_data:
  92                 name->tip_name = tip_name;
  93                 name->taggerdate = taggerdate;
  94                 name->generation = generation;
  95                 name->distance = distance;
  96                 name->from_tag = from_tag;
  97         } else {
  98                 free(to_free);
  99                 return;
 100         }
 101
 102         for (parents = commit->parents;
 103                         parents;
 104                         parents = parents->next, parent_number++) {
 105                 if (parent_number > 1) {
 106                         size_t len;
 107                         char *new_name;
 108
 109                         strip_suffix(tip_name, "^0", &len);
 110                         if (generation > 0)
 111                                 new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
 112                                                    generation, parent_number);
 113                         else
 114                                 new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
 115                                                    parent_number);
 116
 117                         name_rev(parents->item, new_name, taggerdate, 0,
 118                                  distance + MERGE_TRAVERSAL_WEIGHT,
 119                                  from_tag, 0);
 120                 } else {
 121                         name_rev(parents->item, tip_name, taggerdate,
 122                                  generation + 1, distance + 1,
 123                                  from_tag, 0);
 124                 }
 125         }
 126 }
 127
 128 static int subpath_matches(const char *path, const char *filter)
 129 {
 130         const char *subpath = path;
 131
 132         while (subpath) {
 133                 if (!wildmatch(filter, subpath, 0))
 134                         return subpath - path;
 135                 subpath = strchr(subpath, '/');
 136                 if (subpath)
 137                         subpath++;
 138         }
 139         return -1;
 140 }
 141
 142 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
 143 {
 144         if (shorten_unambiguous)
 145                 refname = shorten_unambiguous_ref(refname, 0);
 146         else if (starts_with(refname, "refs/heads/"))
 147                 refname = refname + 11;
 148         else if (starts_with(refname, "refs/"))
 149                 refname = refname + 5;
 150         return refname;
 151 }
 152
 153 struct name_ref_data {
 154         int tags_only;
 155         int name_only;
 156         struct string_list ref_filters;
 157         struct string_list exclude_filters;
 158 };
 159
 160 static struct tip_table {
 161         struct tip_table_entry {
 162                 struct object_id oid;
 163                 const char *refname;
 164         } *table;
 165         int nr;
 166         int alloc;
 167         int sorted;
 168 } tip_table;
 169
 170 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 171                              int shorten_unambiguous)
 172 {
 173         refname = name_ref_abbrev(refname, shorten_unambiguous);
 174
 175         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 176         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 177         tip_table.table[tip_table.nr].refname = xstrdup(refname);
 178         tip_table.nr++;
 179         tip_table.sorted = 0;
 180 }
 181
 182 static int tipcmp(const void *a_, const void *b_)
 183 {
 184         const struct tip_table_entry *a = a_, *b = b_;
 185         return oidcmp(&a->oid, &b->oid);
 186 }
 187
 188 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
 189 {
 190         struct object *o = parse_object(oid);
 191         struct name_ref_data *data = cb_data;
 192         int can_abbreviate_output = data->tags_only && data->name_only;
 193         int deref = 0;
 194         timestamp_t taggerdate = TIME_MAX;
 195
 196         if (data->tags_only && !starts_with(path, "refs/tags/"))
 197                 return 0;
 198
 199         if (data->exclude_filters.nr) {
 200                 struct string_list_item *item;
 201
 202                 for_each_string_list_item(item, &data->exclude_filters) {
 203                         if (subpath_matches(path, item->string) >= 0)
 204                                 return 0;
 205                 }
 206         }
 207
 208         if (data->ref_filters.nr) {
 209                 struct string_list_item *item;
 210                 int matched = 0;
 211
 212                 /* See if any of the patterns match. */
 213                 for_each_string_list_item(item, &data->ref_filters) {
 214                         /*
 215                          * Check all patterns even after finding a match, so
 216                          * that we can see if a match with a subpath exists.
 217                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 218                          * both of which match, the user is showing her
 219                          * willingness to accept a shortened output by having
 220                          * the 'v1.*' in the acceptable refnames, so we
 221                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 222                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 223                          */
 224                         switch (subpath_matches(path, item->string)) {
 225                         case -1: /* did not match */
 226                                 break;
 227                         case 0: /* matched fully */
 228                                 matched = 1;
 229                                 break;
 230                         default: /* matched subpath */
 231                                 matched = 1;
 232                                 can_abbreviate_output = 1;
 233                                 break;
 234                         }
 235                 }
 236
 237                 /* If none of the patterns matched, stop now */
 238                 if (!matched)
 239                         return 0;
 240         }
 241
 242         add_to_tip_table(oid, path, can_abbreviate_output);
 243
 244         while (o && o->type == OBJ_TAG) {
 245                 struct tag *t = (struct tag *) o;
 246                 if (!t->tagged)
 247                         break; /* broken repository */
 248                 o = parse_object(&t->tagged->oid);
 249                 deref = 1;
 250                 taggerdate = t->date;
 251         }
 252         if (o && o->type == OBJ_COMMIT) {
 253                 struct commit *commit = (struct commit *)o;
 254                 int from_tag = starts_with(path, "refs/tags/");
 255
 256                 if (taggerdate == TIME_MAX)
 257                         taggerdate = ((struct commit *)o)->date;
 258                 path = name_ref_abbrev(path, can_abbreviate_output);
 259                 name_rev(commit, xstrdup(path), taggerdate, 0, 0,
 260                          from_tag, deref);
 261         }
 262         return 0;
 263 }
 264
 265 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
 266 {
 267         struct tip_table_entry *table = table_;
 268         return table[ix].oid.hash;
 269 }
 270
 271 static const char *get_exact_ref_match(const struct object *o)
 272 {
 273         int found;
 274
 275         if (!tip_table.table || !tip_table.nr)
 276                 return NULL;
 277
 278         if (!tip_table.sorted) {
 279                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 280                 tip_table.sorted = 1;
 281         }
 282
 283         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
 284                          nth_tip_table_ent);
 285         if (0 <= found)
 286                 return tip_table.table[found].refname;
 287         return NULL;
 288 }
 289
 290 /* may return a constant string or use "buf" as scratch space */
 291 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 292 {
 293         struct rev_name *n;
 294         struct commit *c;
 295
 296         if (o->type != OBJ_COMMIT)
 297                 return get_exact_ref_match(o);
 298         c = (struct commit *) o;
 299         n = c->util;
 300         if (!n)
 301                 return NULL;
 302
 303         if (!n->generation)
 304                 return n->tip_name;
 305         else {
 306                 int len = strlen(n->tip_name);
 307                 if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
 308                         len -= 2;
 309                 strbuf_reset(buf);
 310                 strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
 311                 return buf->buf;
 312         }
 313 }
 314
 315 static void show_name(const struct object *obj,
 316                       const char *caller_name,
 317                       int always, int allow_undefined, int name_only)
 318 {
 319         const char *name;
 320         const struct object_id *oid = &obj->oid;
 321         struct strbuf buf = STRBUF_INIT;
 322
 323         if (!name_only)
 324                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 325         name = get_rev_name(obj, &buf);
 326         if (name)
 327                 printf("%s\n", name);
 328         else if (allow_undefined)
 329                 printf("undefined\n");
 330         else if (always)
 331                 printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV));
 332         else
 333                 die("cannot describe '%s'", oid_to_hex(oid));
 334         strbuf_release(&buf);
 335 }
 336
 337 static char const * const name_rev_usage[] = {
 338         N_("git name-rev [<options>] <commit>..."),
 339         N_("git name-rev [<options>] --all"),
 340         N_("git name-rev [<options>] --stdin"),
 341         NULL
 342 };
 343
 344 static void name_rev_line(char *p, struct name_ref_data *data)
 345 {
 346         struct strbuf buf = STRBUF_INIT;
 347         int forty = 0;
 348         char *p_start;
 349         for (p_start = p; *p; p++) {
 350 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 351                 if (!ishex(*p))
 352                         forty = 0;
 353                 else if (++forty == GIT_SHA1_HEXSZ &&
 354                          !ishex(*(p+1))) {
 355                         struct object_id oid;
 356                         const char *name = NULL;
 357                         char c = *(p+1);
 358                         int p_len = p - p_start + 1;
 359
 360                         forty = 0;
 361
 362                         *(p+1) = 0;
 363                         if (!get_oid(p - (GIT_SHA1_HEXSZ - 1), &oid)) {
 364                                 struct object *o =
 365                                         lookup_object(oid.hash);
 366                                 if (o)
 367                                         name = get_rev_name(o, &buf);
 368                         }
 369                         *(p+1) = c;
 370
 371                         if (!name)
 372                                 continue;
 373
 374                         if (data->name_only)
 375                                 printf("%.*s%s", p_len - GIT_SHA1_HEXSZ, p_start, name);
 376                         else
 377                                 printf("%.*s (%s)", p_len, p_start, name);
 378                         p_start = p + 1;
 379                 }
 380         }
 381
 382         /* flush */
 383         if (p_start != p)
 384                 fwrite(p_start, p - p_start, 1, stdout);
 385
 386         strbuf_release(&buf);
 387 }
 388
 389 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 390 {
 391         struct object_array revs = OBJECT_ARRAY_INIT;
 392         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 393         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 394         struct option opts[] = {
 395                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 396                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 397                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 398                                    N_("only use refs matching <pattern>")),
 399                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 400                                    N_("ignore refs matching <pattern>")),
 401                 OPT_GROUP(""),
 402                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 403                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
 404                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 405                 OPT_BOOL(0, "always",     &always,
 406                            N_("show abbreviated commit object as fallback")),
 407                 {
 408                         /* A Hidden OPT_BOOL */
 409                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 410                         N_("dereference tags in the input (internal use)"),
 411                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 412                 },
 413                 OPT_END(),
 414         };
 415
 416         git_config(git_default_config, NULL);
 417         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 418         if (all + transform_stdin + !!argc > 1) {
 419                 error("Specify either a list, or --all, not both!");
 420                 usage_with_options(name_rev_usage, opts);
 421         }
 422         if (all || transform_stdin)
 423                 cutoff = 0;
 424
 425         for (; argc; argc--, argv++) {
 426                 struct object_id oid;
 427                 struct object *object;
 428                 struct commit *commit;
 429
 430                 if (get_oid(*argv, &oid)) {
 431                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 432                                         *argv);
 433                         continue;
 434                 }
 435
 436                 commit = NULL;
 437                 object = parse_object(&oid);
 438                 if (object) {
 439                         struct object *peeled = deref_tag(object, *argv, 0);
 440                         if (peeled && peeled->type == OBJ_COMMIT)
 441                                 commit = (struct commit *)peeled;
 442                 }
 443
 444                 if (!object) {
 445                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 446                                         *argv);
 447                         continue;
 448                 }
 449
 450                 if (commit) {
 451                         if (cutoff > commit->date)
 452                                 cutoff = commit->date;
 453                 }
 454
 455                 if (peel_tag) {
 456                         if (!commit) {
 457                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 458                                         *argv);
 459                                 continue;
 460                         }
 461                         object = (struct object *)commit;
 462                 }
 463                 add_object_array(object, *argv, &revs);
 464         }
 465
 466         if (cutoff)
 467                 cutoff = cutoff - CUTOFF_DATE_SLOP;
 468         for_each_ref(name_ref, &data);
 469
 470         if (transform_stdin) {
 471                 char buffer[2048];
 472
 473                 while (!feof(stdin)) {
 474                         char *p = fgets(buffer, sizeof(buffer), stdin);
 475                         if (!p)
 476                                 break;
 477                         name_rev_line(p, &data);
 478                 }
 479         } else if (all) {
 480                 int i, max;
 481
 482                 max = get_max_object_index();
 483                 for (i = 0; i < max; i++) {
 484                         struct object *obj = get_indexed_object(i);
 485                         if (!obj || obj->type != OBJ_COMMIT)
 486                                 continue;
 487                         show_name(obj, NULL,
 488                                   always, allow_undefined, data.name_only);
 489                 }
 490         } else {
 491                 int i;
 492                 for (i = 0; i < revs.nr; i++)
 493                         show_name(revs.objects[i].item, revs.objects[i].name,
 494                                   always, allow_undefined, data.name_only);
 495         }
 496
 497         UNLEAK(revs);
 498         return 0;
 499 }