builtin/name-rev.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "commit.h"
   4 #include "tag.h"
   5 #include "refs.h"
   6 #include "parse-options.h"
   7 #include "sha1-lookup.h"
   8
   9 #define CUTOFF_DATE_SLOP 86400 /* one day */
  10
  11 typedef struct rev_name {
  12         const char *tip_name;
  13         unsigned long taggerdate;
  14         int generation;
  15         int distance;
  16         int from_tag;
  17 } rev_name;
  18
  19 static long cutoff = LONG_MAX;
  20
  21 /* How many generations are maximally preferred over _one_ merge traversal? */
  22 #define MERGE_TRAVERSAL_WEIGHT 65535
  23
  24 static int is_better_name(struct rev_name *name,
  25                           const char *tip_name,
  26                           unsigned long taggerdate,
  27                           int generation,
  28                           int distance,
  29                           int from_tag)
  30 {
  31         /*
  32          * When comparing names based on tags, prefer names
  33          * based on the older tag, even if it is farther away.
  34          */
  35         if (from_tag && name->from_tag)
  36                 return (name->taggerdate > taggerdate ||
  37                         (name->taggerdate == taggerdate &&
  38                          name->distance > distance));
  39
  40         /*
  41          * We know that at least one of them is a non-tag at this point.
  42          * favor a tag over a non-tag.
  43          */
  44         if (name->from_tag != from_tag)
  45                 return from_tag;
  46
  47         /*
  48          * We are now looking at two non-tags.  Tiebreak to favor
  49          * shorter hops.
  50          */
  51         if (name->distance != distance)
  52                 return name->distance > distance;
  53
  54         /* ... or tiebreak to favor older date */
  55         if (name->taggerdate != taggerdate)
  56                 return name->taggerdate > taggerdate;
  57
  58         /* keep the current one if we cannot decide */
  59         return 0;
  60 }
  61
  62 static void name_rev(struct commit *commit,
  63                 const char *tip_name, unsigned long taggerdate,
  64                 int generation, int distance, int from_tag,
  65                 int deref)
  66 {
  67         struct rev_name *name = (struct rev_name *)commit->util;
  68         struct commit_list *parents;
  69         int parent_number = 1;
  70         char *to_free = NULL;
  71
  72         parse_commit(commit);
  73
  74         if (commit->date < cutoff)
  75                 return;
  76
  77         if (deref) {
  78                 tip_name = to_free = xstrfmt("%s^0", tip_name);
  79
  80                 if (generation)
  81                         die("generation: %d, but deref?", generation);
  82         }
  83
  84         if (name == NULL) {
  85                 name = xmalloc(sizeof(rev_name));
  86                 commit->util = name;
  87                 goto copy_data;
  88         } else if (is_better_name(name, tip_name, taggerdate,
  89                                   generation, distance, from_tag)) {
  90 copy_data:
  91                 name->tip_name = tip_name;
  92                 name->taggerdate = taggerdate;
  93                 name->generation = generation;
  94                 name->distance = distance;
  95                 name->from_tag = from_tag;
  96         } else {
  97                 free(to_free);
  98                 return;
  99         }
 100
 101         for (parents = commit->parents;
 102                         parents;
 103                         parents = parents->next, parent_number++) {
 104                 if (parent_number > 1) {
 105                         size_t len;
 106                         char *new_name;
 107
 108                         strip_suffix(tip_name, "^0", &len);
 109                         if (generation > 0)
 110                                 new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
 111                                                    generation, parent_number);
 112                         else
 113                                 new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
 114                                                    parent_number);
 115
 116                         name_rev(parents->item, new_name, taggerdate, 0,
 117                                  distance + MERGE_TRAVERSAL_WEIGHT,
 118                                  from_tag, 0);
 119                 } else {
 120                         name_rev(parents->item, tip_name, taggerdate,
 121                                  generation + 1, distance + 1,
 122                                  from_tag, 0);
 123                 }
 124         }
 125 }
 126
 127 static int subpath_matches(const char *path, const char *filter)
 128 {
 129         const char *subpath = path;
 130
 131         while (subpath) {
 132                 if (!wildmatch(filter, subpath, 0, NULL))
 133                         return subpath - path;
 134                 subpath = strchr(subpath, '/');
 135                 if (subpath)
 136                         subpath++;
 137         }
 138         return -1;
 139 }
 140
 141 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
 142 {
 143         if (shorten_unambiguous)
 144                 refname = shorten_unambiguous_ref(refname, 0);
 145         else if (starts_with(refname, "refs/heads/"))
 146                 refname = refname + 11;
 147         else if (starts_with(refname, "refs/"))
 148                 refname = refname + 5;
 149         return refname;
 150 }
 151
 152 struct name_ref_data {
 153         int tags_only;
 154         int name_only;
 155         struct string_list ref_filters;
 156         struct string_list exclude_filters;
 157 };
 158
 159 static struct tip_table {
 160         struct tip_table_entry {
 161                 unsigned char sha1[20];
 162                 const char *refname;
 163         } *table;
 164         int nr;
 165         int alloc;
 166         int sorted;
 167 } tip_table;
 168
 169 static void add_to_tip_table(const unsigned char *sha1, const char *refname,
 170                              int shorten_unambiguous)
 171 {
 172         refname = name_ref_abbrev(refname, shorten_unambiguous);
 173
 174         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 175         hashcpy(tip_table.table[tip_table.nr].sha1, sha1);
 176         tip_table.table[tip_table.nr].refname = xstrdup(refname);
 177         tip_table.nr++;
 178         tip_table.sorted = 0;
 179 }
 180
 181 static int tipcmp(const void *a_, const void *b_)
 182 {
 183         const struct tip_table_entry *a = a_, *b = b_;
 184         return hashcmp(a->sha1, b->sha1);
 185 }
 186
 187 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
 188 {
 189         struct object *o = parse_object(oid->hash);
 190         struct name_ref_data *data = cb_data;
 191         int can_abbreviate_output = data->tags_only && data->name_only;
 192         int deref = 0;
 193         unsigned long taggerdate = ULONG_MAX;
 194
 195         if (data->tags_only && !starts_with(path, "refs/tags/"))
 196                 return 0;
 197
 198         if (data->exclude_filters.nr) {
 199                 struct string_list_item *item;
 200
 201                 for_each_string_list_item(item, &data->exclude_filters) {
 202                         if (subpath_matches(path, item->string) >= 0)
 203                                 return 0;
 204                 }
 205         }
 206
 207         if (data->ref_filters.nr) {
 208                 struct string_list_item *item;
 209                 int matched = 0;
 210
 211                 /* See if any of the patterns match. */
 212                 for_each_string_list_item(item, &data->ref_filters) {
 213                         /*
 214                          * Check all patterns even after finding a match, so
 215                          * that we can see if a match with a subpath exists.
 216                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 217                          * both of which match, the user is showing her
 218                          * willingness to accept a shortened output by having
 219                          * the 'v1.*' in the acceptable refnames, so we
 220                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 221                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 222                          */
 223                         switch (subpath_matches(path, item->string)) {
 224                         case -1: /* did not match */
 225                                 break;
 226                         case 0: /* matched fully */
 227                                 matched = 1;
 228                                 break;
 229                         default: /* matched subpath */
 230                                 matched = 1;
 231                                 can_abbreviate_output = 1;
 232                                 break;
 233                         }
 234                 }
 235
 236                 /* If none of the patterns matched, stop now */
 237                 if (!matched)
 238                         return 0;
 239         }
 240
 241         add_to_tip_table(oid->hash, path, can_abbreviate_output);
 242
 243         while (o && o->type == OBJ_TAG) {
 244                 struct tag *t = (struct tag *) o;
 245                 if (!t->tagged)
 246                         break; /* broken repository */
 247                 o = parse_object(t->tagged->oid.hash);
 248                 deref = 1;
 249                 taggerdate = t->date;
 250         }
 251         if (o && o->type == OBJ_COMMIT) {
 252                 struct commit *commit = (struct commit *)o;
 253                 int from_tag = starts_with(path, "refs/tags/");
 254
 255                 if (taggerdate == ULONG_MAX)
 256                         taggerdate = ((struct commit *)o)->date;
 257                 path = name_ref_abbrev(path, can_abbreviate_output);
 258                 name_rev(commit, xstrdup(path), taggerdate, 0, 0,
 259                          from_tag, deref);
 260         }
 261         return 0;
 262 }
 263
 264 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
 265 {
 266         struct tip_table_entry *table = table_;
 267         return table[ix].sha1;
 268 }
 269
 270 static const char *get_exact_ref_match(const struct object *o)
 271 {
 272         int found;
 273
 274         if (!tip_table.table || !tip_table.nr)
 275                 return NULL;
 276
 277         if (!tip_table.sorted) {
 278                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 279                 tip_table.sorted = 1;
 280         }
 281
 282         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
 283                          nth_tip_table_ent);
 284         if (0 <= found)
 285                 return tip_table.table[found].refname;
 286         return NULL;
 287 }
 288
 289 /* may return a constant string or use "buf" as scratch space */
 290 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 291 {
 292         struct rev_name *n;
 293         struct commit *c;
 294
 295         if (o->type != OBJ_COMMIT)
 296                 return get_exact_ref_match(o);
 297         c = (struct commit *) o;
 298         n = c->util;
 299         if (!n)
 300                 return NULL;
 301
 302         if (!n->generation)
 303                 return n->tip_name;
 304         else {
 305                 int len = strlen(n->tip_name);
 306                 if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
 307                         len -= 2;
 308                 strbuf_reset(buf);
 309                 strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
 310                 return buf->buf;
 311         }
 312 }
 313
 314 static void show_name(const struct object *obj,
 315                       const char *caller_name,
 316                       int always, int allow_undefined, int name_only)
 317 {
 318         const char *name;
 319         const struct object_id *oid = &obj->oid;
 320         struct strbuf buf = STRBUF_INIT;
 321
 322         if (!name_only)
 323                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 324         name = get_rev_name(obj, &buf);
 325         if (name)
 326                 printf("%s\n", name);
 327         else if (allow_undefined)
 328                 printf("undefined\n");
 329         else if (always)
 330                 printf("%s\n", find_unique_abbrev(oid->hash, DEFAULT_ABBREV));
 331         else
 332                 die("cannot describe '%s'", oid_to_hex(oid));
 333         strbuf_release(&buf);
 334 }
 335
 336 static char const * const name_rev_usage[] = {
 337         N_("git name-rev [<options>] <commit>..."),
 338         N_("git name-rev [<options>] --all"),
 339         N_("git name-rev [<options>] --stdin"),
 340         NULL
 341 };
 342
 343 static void name_rev_line(char *p, struct name_ref_data *data)
 344 {
 345         struct strbuf buf = STRBUF_INIT;
 346         int forty = 0;
 347         char *p_start;
 348         for (p_start = p; *p; p++) {
 349 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 350                 if (!ishex(*p))
 351                         forty = 0;
 352                 else if (++forty == 40 &&
 353                          !ishex(*(p+1))) {
 354                         unsigned char sha1[40];
 355                         const char *name = NULL;
 356                         char c = *(p+1);
 357                         int p_len = p - p_start + 1;
 358
 359                         forty = 0;
 360
 361                         *(p+1) = 0;
 362                         if (!get_sha1(p - 39, sha1)) {
 363                                 struct object *o =
 364                                         lookup_object(sha1);
 365                                 if (o)
 366                                         name = get_rev_name(o, &buf);
 367                         }
 368                         *(p+1) = c;
 369
 370                         if (!name)
 371                                 continue;
 372
 373                         if (data->name_only)
 374                                 printf("%.*s%s", p_len - 40, p_start, name);
 375                         else
 376                                 printf("%.*s (%s)", p_len, p_start, name);
 377                         p_start = p + 1;
 378                 }
 379         }
 380
 381         /* flush */
 382         if (p_start != p)
 383                 fwrite(p_start, p - p_start, 1, stdout);
 384
 385         strbuf_release(&buf);
 386 }
 387
 388 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 389 {
 390         struct object_array revs = OBJECT_ARRAY_INIT;
 391         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 392         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 393         struct option opts[] = {
 394                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 395                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 396                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 397                                    N_("only use refs matching <pattern>")),
 398                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 399                                    N_("ignore refs matching <pattern>")),
 400                 OPT_GROUP(""),
 401                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 402                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
 403                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 404                 OPT_BOOL(0, "always",     &always,
 405                            N_("show abbreviated commit object as fallback")),
 406                 {
 407                         /* A Hidden OPT_BOOL */
 408                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 409                         N_("dereference tags in the input (internal use)"),
 410                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 411                 },
 412                 OPT_END(),
 413         };
 414
 415         git_config(git_default_config, NULL);
 416         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 417         if (all + transform_stdin + !!argc > 1) {
 418                 error("Specify either a list, or --all, not both!");
 419                 usage_with_options(name_rev_usage, opts);
 420         }
 421         if (all || transform_stdin)
 422                 cutoff = 0;
 423
 424         for (; argc; argc--, argv++) {
 425                 unsigned char sha1[20];
 426                 struct object *object;
 427                 struct commit *commit;
 428
 429                 if (get_sha1(*argv, sha1)) {
 430                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 431                                         *argv);
 432                         continue;
 433                 }
 434
 435                 commit = NULL;
 436                 object = parse_object(sha1);
 437                 if (object) {
 438                         struct object *peeled = deref_tag(object, *argv, 0);
 439                         if (peeled && peeled->type == OBJ_COMMIT)
 440                                 commit = (struct commit *)peeled;
 441                 }
 442
 443                 if (!object) {
 444                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 445                                         *argv);
 446                         continue;
 447                 }
 448
 449                 if (commit) {
 450                         if (cutoff > commit->date)
 451                                 cutoff = commit->date;
 452                 }
 453
 454                 if (peel_tag) {
 455                         if (!commit) {
 456                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 457                                         *argv);
 458                                 continue;
 459                         }
 460                         object = (struct object *)commit;
 461                 }
 462                 add_object_array(object, *argv, &revs);
 463         }
 464
 465         if (cutoff)
 466                 cutoff = cutoff - CUTOFF_DATE_SLOP;
 467         for_each_ref(name_ref, &data);
 468
 469         if (transform_stdin) {
 470                 char buffer[2048];
 471
 472                 while (!feof(stdin)) {
 473                         char *p = fgets(buffer, sizeof(buffer), stdin);
 474                         if (!p)
 475                                 break;
 476                         name_rev_line(p, &data);
 477                 }
 478         } else if (all) {
 479                 int i, max;
 480
 481                 max = get_max_object_index();
 482                 for (i = 0; i < max; i++) {
 483                         struct object *obj = get_indexed_object(i);
 484                         if (!obj || obj->type != OBJ_COMMIT)
 485                                 continue;
 486                         show_name(obj, NULL,
 487                                   always, allow_undefined, data.name_only);
 488                 }
 489         } else {
 490                 int i;
 491                 for (i = 0; i < revs.nr; i++)
 492                         show_name(revs.objects[i].item, revs.objects[i].name,
 493                                   always, allow_undefined, data.name_only);
 494         }
 495
 496         return 0;
 497 }