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 #include "commit-slab.h"
  10
  11 #define CUTOFF_DATE_SLOP 86400 /* one day */
  12
  13 typedef struct rev_name {
  14         const char *tip_name;
  15         timestamp_t taggerdate;
  16         int generation;
  17         int distance;
  18         int from_tag;
  19 } rev_name;
  20
  21 define_commit_slab(commit_rev_name, struct rev_name *);
  22
  23 static timestamp_t cutoff = TIME_MAX;
  24 static struct commit_rev_name rev_names;
  25
  26 /* How many generations are maximally preferred over _one_ merge traversal? */
  27 #define MERGE_TRAVERSAL_WEIGHT 65535
  28
  29 static struct rev_name *get_commit_rev_name(struct commit *commit)
  30 {
  31         struct rev_name **slot = commit_rev_name_peek(&rev_names, commit);
  32
  33         return slot ? *slot : NULL;
  34 }
  35
  36 static void set_commit_rev_name(struct commit *commit, struct rev_name *name)
  37 {
  38         *commit_rev_name_at(&rev_names, commit) = name;
  39 }
  40
  41 static int is_better_name(struct rev_name *name,
  42                           const char *tip_name,
  43                           timestamp_t taggerdate,
  44                           int generation,
  45                           int distance,
  46                           int from_tag)
  47 {
  48         /*
  49          * When comparing names based on tags, prefer names
  50          * based on the older tag, even if it is farther away.
  51          */
  52         if (from_tag && name->from_tag)
  53                 return (name->taggerdate > taggerdate ||
  54                         (name->taggerdate == taggerdate &&
  55                          name->distance > distance));
  56
  57         /*
  58          * We know that at least one of them is a non-tag at this point.
  59          * favor a tag over a non-tag.
  60          */
  61         if (name->from_tag != from_tag)
  62                 return from_tag;
  63
  64         /*
  65          * We are now looking at two non-tags.  Tiebreak to favor
  66          * shorter hops.
  67          */
  68         if (name->distance != distance)
  69                 return name->distance > distance;
  70
  71         /* ... or tiebreak to favor older date */
  72         if (name->taggerdate != taggerdate)
  73                 return name->taggerdate > taggerdate;
  74
  75         /* keep the current one if we cannot decide */
  76         return 0;
  77 }
  78
  79 static void name_rev(struct commit *commit,
  80                 const char *tip_name, timestamp_t taggerdate,
  81                 int generation, int distance, int from_tag,
  82                 int deref)
  83 {
  84         struct rev_name *name = get_commit_rev_name(commit);
  85         struct commit_list *parents;
  86         int parent_number = 1;
  87         char *to_free = NULL;
  88
  89         parse_commit(commit);
  90
  91         if (commit->date < cutoff)
  92                 return;
  93
  94         if (deref) {
  95                 tip_name = to_free = xstrfmt("%s^0", tip_name);
  96
  97                 if (generation)
  98                         die("generation: %d, but deref?", generation);
  99         }
 100
 101         if (name == NULL) {
 102                 name = xmalloc(sizeof(rev_name));
 103                 set_commit_rev_name(commit, name);
 104                 goto copy_data;
 105         } else if (is_better_name(name, tip_name, taggerdate,
 106                                   generation, distance, from_tag)) {
 107 copy_data:
 108                 name->tip_name = tip_name;
 109                 name->taggerdate = taggerdate;
 110                 name->generation = generation;
 111                 name->distance = distance;
 112                 name->from_tag = from_tag;
 113         } else {
 114                 free(to_free);
 115                 return;
 116         }
 117
 118         for (parents = commit->parents;
 119                         parents;
 120                         parents = parents->next, parent_number++) {
 121                 if (parent_number > 1) {
 122                         size_t len;
 123                         char *new_name;
 124
 125                         strip_suffix(tip_name, "^0", &len);
 126                         if (generation > 0)
 127                                 new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
 128                                                    generation, parent_number);
 129                         else
 130                                 new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
 131                                                    parent_number);
 132
 133                         name_rev(parents->item, new_name, taggerdate, 0,
 134                                  distance + MERGE_TRAVERSAL_WEIGHT,
 135                                  from_tag, 0);
 136                 } else {
 137                         name_rev(parents->item, tip_name, taggerdate,
 138                                  generation + 1, distance + 1,
 139                                  from_tag, 0);
 140                 }
 141         }
 142 }
 143
 144 static int subpath_matches(const char *path, const char *filter)
 145 {
 146         const char *subpath = path;
 147
 148         while (subpath) {
 149                 if (!wildmatch(filter, subpath, 0))
 150                         return subpath - path;
 151                 subpath = strchr(subpath, '/');
 152                 if (subpath)
 153                         subpath++;
 154         }
 155         return -1;
 156 }
 157
 158 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
 159 {
 160         if (shorten_unambiguous)
 161                 refname = shorten_unambiguous_ref(refname, 0);
 162         else if (starts_with(refname, "refs/heads/"))
 163                 refname = refname + 11;
 164         else if (starts_with(refname, "refs/"))
 165                 refname = refname + 5;
 166         return refname;
 167 }
 168
 169 struct name_ref_data {
 170         int tags_only;
 171         int name_only;
 172         struct string_list ref_filters;
 173         struct string_list exclude_filters;
 174 };
 175
 176 static struct tip_table {
 177         struct tip_table_entry {
 178                 struct object_id oid;
 179                 const char *refname;
 180         } *table;
 181         int nr;
 182         int alloc;
 183         int sorted;
 184 } tip_table;
 185
 186 static void add_to_tip_table(const struct object_id *oid, const char *refname,
 187                              int shorten_unambiguous)
 188 {
 189         refname = name_ref_abbrev(refname, shorten_unambiguous);
 190
 191         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
 192         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
 193         tip_table.table[tip_table.nr].refname = xstrdup(refname);
 194         tip_table.nr++;
 195         tip_table.sorted = 0;
 196 }
 197
 198 static int tipcmp(const void *a_, const void *b_)
 199 {
 200         const struct tip_table_entry *a = a_, *b = b_;
 201         return oidcmp(&a->oid, &b->oid);
 202 }
 203
 204 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
 205 {
 206         struct object *o = parse_object(oid);
 207         struct name_ref_data *data = cb_data;
 208         int can_abbreviate_output = data->tags_only && data->name_only;
 209         int deref = 0;
 210         timestamp_t taggerdate = TIME_MAX;
 211
 212         if (data->tags_only && !starts_with(path, "refs/tags/"))
 213                 return 0;
 214
 215         if (data->exclude_filters.nr) {
 216                 struct string_list_item *item;
 217
 218                 for_each_string_list_item(item, &data->exclude_filters) {
 219                         if (subpath_matches(path, item->string) >= 0)
 220                                 return 0;
 221                 }
 222         }
 223
 224         if (data->ref_filters.nr) {
 225                 struct string_list_item *item;
 226                 int matched = 0;
 227
 228                 /* See if any of the patterns match. */
 229                 for_each_string_list_item(item, &data->ref_filters) {
 230                         /*
 231                          * Check all patterns even after finding a match, so
 232                          * that we can see if a match with a subpath exists.
 233                          * When a user asked for 'refs/tags/v*' and 'v1.*',
 234                          * both of which match, the user is showing her
 235                          * willingness to accept a shortened output by having
 236                          * the 'v1.*' in the acceptable refnames, so we
 237                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
 238                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
 239                          */
 240                         switch (subpath_matches(path, item->string)) {
 241                         case -1: /* did not match */
 242                                 break;
 243                         case 0: /* matched fully */
 244                                 matched = 1;
 245                                 break;
 246                         default: /* matched subpath */
 247                                 matched = 1;
 248                                 can_abbreviate_output = 1;
 249                                 break;
 250                         }
 251                 }
 252
 253                 /* If none of the patterns matched, stop now */
 254                 if (!matched)
 255                         return 0;
 256         }
 257
 258         add_to_tip_table(oid, path, can_abbreviate_output);
 259
 260         while (o && o->type == OBJ_TAG) {
 261                 struct tag *t = (struct tag *) o;
 262                 if (!t->tagged)
 263                         break; /* broken repository */
 264                 o = parse_object(&t->tagged->oid);
 265                 deref = 1;
 266                 taggerdate = t->date;
 267         }
 268         if (o && o->type == OBJ_COMMIT) {
 269                 struct commit *commit = (struct commit *)o;
 270                 int from_tag = starts_with(path, "refs/tags/");
 271
 272                 if (taggerdate == TIME_MAX)
 273                         taggerdate = ((struct commit *)o)->date;
 274                 path = name_ref_abbrev(path, can_abbreviate_output);
 275                 name_rev(commit, xstrdup(path), taggerdate, 0, 0,
 276                          from_tag, deref);
 277         }
 278         return 0;
 279 }
 280
 281 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
 282 {
 283         struct tip_table_entry *table = table_;
 284         return table[ix].oid.hash;
 285 }
 286
 287 static const char *get_exact_ref_match(const struct object *o)
 288 {
 289         int found;
 290
 291         if (!tip_table.table || !tip_table.nr)
 292                 return NULL;
 293
 294         if (!tip_table.sorted) {
 295                 QSORT(tip_table.table, tip_table.nr, tipcmp);
 296                 tip_table.sorted = 1;
 297         }
 298
 299         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
 300                          nth_tip_table_ent);
 301         if (0 <= found)
 302                 return tip_table.table[found].refname;
 303         return NULL;
 304 }
 305
 306 /* may return a constant string or use "buf" as scratch space */
 307 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
 308 {
 309         struct rev_name *n;
 310         struct commit *c;
 311
 312         if (o->type != OBJ_COMMIT)
 313                 return get_exact_ref_match(o);
 314         c = (struct commit *) o;
 315         n = get_commit_rev_name(c);
 316         if (!n)
 317                 return NULL;
 318
 319         if (!n->generation)
 320                 return n->tip_name;
 321         else {
 322                 int len = strlen(n->tip_name);
 323                 if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
 324                         len -= 2;
 325                 strbuf_reset(buf);
 326                 strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
 327                 return buf->buf;
 328         }
 329 }
 330
 331 static void show_name(const struct object *obj,
 332                       const char *caller_name,
 333                       int always, int allow_undefined, int name_only)
 334 {
 335         const char *name;
 336         const struct object_id *oid = &obj->oid;
 337         struct strbuf buf = STRBUF_INIT;
 338
 339         if (!name_only)
 340                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
 341         name = get_rev_name(obj, &buf);
 342         if (name)
 343                 printf("%s\n", name);
 344         else if (allow_undefined)
 345                 printf("undefined\n");
 346         else if (always)
 347                 printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV));
 348         else
 349                 die("cannot describe '%s'", oid_to_hex(oid));
 350         strbuf_release(&buf);
 351 }
 352
 353 static char const * const name_rev_usage[] = {
 354         N_("git name-rev [<options>] <commit>..."),
 355         N_("git name-rev [<options>] --all"),
 356         N_("git name-rev [<options>] --stdin"),
 357         NULL
 358 };
 359
 360 static void name_rev_line(char *p, struct name_ref_data *data)
 361 {
 362         struct strbuf buf = STRBUF_INIT;
 363         int forty = 0;
 364         char *p_start;
 365         for (p_start = p; *p; p++) {
 366 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
 367                 if (!ishex(*p))
 368                         forty = 0;
 369                 else if (++forty == GIT_SHA1_HEXSZ &&
 370                          !ishex(*(p+1))) {
 371                         struct object_id oid;
 372                         const char *name = NULL;
 373                         char c = *(p+1);
 374                         int p_len = p - p_start + 1;
 375
 376                         forty = 0;
 377
 378                         *(p+1) = 0;
 379                         if (!get_oid(p - (GIT_SHA1_HEXSZ - 1), &oid)) {
 380                                 struct object *o =
 381                                         lookup_object(oid.hash);
 382                                 if (o)
 383                                         name = get_rev_name(o, &buf);
 384                         }
 385                         *(p+1) = c;
 386
 387                         if (!name)
 388                                 continue;
 389
 390                         if (data->name_only)
 391                                 printf("%.*s%s", p_len - GIT_SHA1_HEXSZ, p_start, name);
 392                         else
 393                                 printf("%.*s (%s)", p_len, p_start, name);
 394                         p_start = p + 1;
 395                 }
 396         }
 397
 398         /* flush */
 399         if (p_start != p)
 400                 fwrite(p_start, p - p_start, 1, stdout);
 401
 402         strbuf_release(&buf);
 403 }
 404
 405 int cmd_name_rev(int argc, const char **argv, const char *prefix)
 406 {
 407         struct object_array revs = OBJECT_ARRAY_INIT;
 408         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
 409         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 410         struct option opts[] = {
 411                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 412                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
 413                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 414                                    N_("only use refs matching <pattern>")),
 415                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
 416                                    N_("ignore refs matching <pattern>")),
 417                 OPT_GROUP(""),
 418                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 419                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
 420                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
 421                 OPT_BOOL(0, "always",     &always,
 422                            N_("show abbreviated commit object as fallback")),
 423                 {
 424                         /* A Hidden OPT_BOOL */
 425                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
 426                         N_("dereference tags in the input (internal use)"),
 427                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
 428                 },
 429                 OPT_END(),
 430         };
 431
 432         init_commit_rev_name(&rev_names);
 433         git_config(git_default_config, NULL);
 434         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
 435         if (all + transform_stdin + !!argc > 1) {
 436                 error("Specify either a list, or --all, not both!");
 437                 usage_with_options(name_rev_usage, opts);
 438         }
 439         if (all || transform_stdin)
 440                 cutoff = 0;
 441
 442         for (; argc; argc--, argv++) {
 443                 struct object_id oid;
 444                 struct object *object;
 445                 struct commit *commit;
 446
 447                 if (get_oid(*argv, &oid)) {
 448                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
 449                                         *argv);
 450                         continue;
 451                 }
 452
 453                 commit = NULL;
 454                 object = parse_object(&oid);
 455                 if (object) {
 456                         struct object *peeled = deref_tag(object, *argv, 0);
 457                         if (peeled && peeled->type == OBJ_COMMIT)
 458                                 commit = (struct commit *)peeled;
 459                 }
 460
 461                 if (!object) {
 462                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
 463                                         *argv);
 464                         continue;
 465                 }
 466
 467                 if (commit) {
 468                         if (cutoff > commit->date)
 469                                 cutoff = commit->date;
 470                 }
 471
 472                 if (peel_tag) {
 473                         if (!commit) {
 474                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
 475                                         *argv);
 476                                 continue;
 477                         }
 478                         object = (struct object *)commit;
 479                 }
 480                 add_object_array(object, *argv, &revs);
 481         }
 482
 483         if (cutoff)
 484                 cutoff = cutoff - CUTOFF_DATE_SLOP;
 485         for_each_ref(name_ref, &data);
 486
 487         if (transform_stdin) {
 488                 char buffer[2048];
 489
 490                 while (!feof(stdin)) {
 491                         char *p = fgets(buffer, sizeof(buffer), stdin);
 492                         if (!p)
 493                                 break;
 494                         name_rev_line(p, &data);
 495                 }
 496         } else if (all) {
 497                 int i, max;
 498
 499                 max = get_max_object_index();
 500                 for (i = 0; i < max; i++) {
 501                         struct object *obj = get_indexed_object(i);
 502                         if (!obj || obj->type != OBJ_COMMIT)
 503                                 continue;
 504                         show_name(obj, NULL,
 505                                   always, allow_undefined, data.name_only);
 506                 }
 507         } else {
 508                 int i;
 509                 for (i = 0; i < revs.nr; i++)
 510                         show_name(revs.objects[i].item, revs.objects[i].name,
 511                                   always, allow_undefined, data.name_only);
 512         }
 513
 514         UNLEAK(revs);
 515         return 0;
 516 }