Andrew's git / gitweb.git / builtin/name-rev.c
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builtin / name-rev.con commit p5551: add a script to test fetch pack-dir rescans (7893bf1)
   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
  12typedef 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
  20static timestamp_t cutoff = TIME_MAX;
  21
  22/* How many generations are maximally preferred over _one_ merge traversal? */
  23#define MERGE_TRAVERSAL_WEIGHT 65535
  24
  25static 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
  63static 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)) {
  91copy_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
 128static 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
 142static 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
 153struct 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
 160static 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
 170static 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
 182static 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
 188static 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
 265static 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
 271static 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 */
 291static 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
 315static 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->hash, DEFAULT_ABBREV));
 332        else
 333                die("cannot describe '%s'", oid_to_hex(oid));
 334        strbuf_release(&buf);
 335}
 336
 337static 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
 344static 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
 389int 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        return 0;
 498}