Andrew's git / gitweb.git / show-branch.c
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show-branch.con commit Make git-pack-redundant non-horribly slow on large sets of packs (751a71e)
   1#include <stdlib.h>
   2#include "cache.h"
   3#include "commit.h"
   4#include "refs.h"
   5
   6static const char show_branch_usage[] =
   7"git-show-branch [--all] [--heads] [--tags] [--more=count | --list | --independent | --merge-base ] [<refs>...]";
   8
   9#define UNINTERESTING   01
  10
  11#define REV_SHIFT        2
  12#define MAX_REVS        29 /* should not exceed bits_per_int - REV_SHIFT */
  13
  14static struct commit *interesting(struct commit_list *list)
  15{
  16        while (list) {
  17                struct commit *commit = list->item;
  18                list = list->next;
  19                if (commit->object.flags & UNINTERESTING)
  20                        continue;
  21                return commit;
  22        }
  23        return NULL;
  24}
  25
  26static struct commit *pop_one_commit(struct commit_list **list_p)
  27{
  28        struct commit *commit;
  29        struct commit_list *list;
  30        list = *list_p;
  31        commit = list->item;
  32        *list_p = list->next;
  33        free(list);
  34        return commit;
  35}
  36
  37struct commit_name {
  38        const char *head_name; /* which head's ancestor? */
  39        int generation; /* how many parents away from head_name */
  40};
  41
  42/* Name the commit as nth generation ancestor of head_name;
  43 * we count only the first-parent relationship for naming purposes.
  44 */
  45static void name_commit(struct commit *commit, const char *head_name, int nth)
  46{
  47        struct commit_name *name;
  48        if (!commit->object.util)
  49                commit->object.util = xmalloc(sizeof(struct commit_name));
  50        name = commit->object.util;
  51        name->head_name = head_name;
  52        name->generation = nth;
  53}
  54
  55/* Parent is the first parent of the commit.  We may name it
  56 * as (n+1)th generation ancestor of the same head_name as
  57 * commit is nth generation ancestore of, if that generation
  58 * number is better than the name it already has.
  59 */
  60static void name_parent(struct commit *commit, struct commit *parent)
  61{
  62        struct commit_name *commit_name = commit->object.util;
  63        struct commit_name *parent_name = parent->object.util;
  64        if (!commit_name)
  65                return;
  66        if (!parent_name ||
  67            commit_name->generation + 1 < parent_name->generation)
  68                name_commit(parent, commit_name->head_name,
  69                            commit_name->generation + 1);
  70}
  71
  72static int name_first_parent_chain(struct commit *c)
  73{
  74        int i = 0;
  75        while (c) {
  76                struct commit *p;
  77                if (!c->object.util)
  78                        break;
  79                if (!c->parents)
  80                        break;
  81                p = c->parents->item;
  82                if (!p->object.util) {
  83                        name_parent(c, p);
  84                        i++;
  85                }
  86                c = p;
  87        }
  88        return i;
  89}
  90
  91static void name_commits(struct commit_list *list,
  92                         struct commit **rev,
  93                         char **ref_name,
  94                         int num_rev)
  95{
  96        struct commit_list *cl;
  97        struct commit *c;
  98        int i;
  99
 100        /* First give names to the given heads */
 101        for (cl = list; cl; cl = cl->next) {
 102                c = cl->item;
 103                if (c->object.util)
 104                        continue;
 105                for (i = 0; i < num_rev; i++) {
 106                        if (rev[i] == c) {
 107                                name_commit(c, ref_name[i], 0);
 108                                break;
 109                        }
 110                }
 111        }
 112
 113        /* Then commits on the first parent ancestry chain */
 114        do {
 115                i = 0;
 116                for (cl = list; cl; cl = cl->next) {
 117                        i += name_first_parent_chain(cl->item);
 118                }
 119        } while (i);
 120
 121        /* Finally, any unnamed commits */
 122        do {
 123                i = 0;
 124                for (cl = list; cl; cl = cl->next) {
 125                        struct commit_list *parents;
 126                        struct commit_name *n;
 127                        int nth;
 128                        c = cl->item;
 129                        if (!c->object.util)
 130                                continue;
 131                        n = c->object.util;
 132                        parents = c->parents;
 133                        nth = 0;
 134                        while (parents) {
 135                                struct commit *p = parents->item;
 136                                char newname[1000], *en;
 137                                parents = parents->next;
 138                                nth++;
 139                                if (p->object.util)
 140                                        continue;
 141                                en = newname;
 142                                switch (n->generation) {
 143                                case 0:
 144                                        en += sprintf(en, "%s", n->head_name);
 145                                        break;
 146                                case 1:
 147                                        en += sprintf(en, "%s^", n->head_name);
 148                                        break;
 149                                default:
 150                                        en += sprintf(en, "%s~%d",
 151                                                n->head_name, n->generation);
 152                                        break;
 153                                }
 154                                if (nth == 1)
 155                                        en += sprintf(en, "^");
 156                                else
 157                                        en += sprintf(en, "^%d", nth);
 158                                name_commit(p, strdup(newname), 0);
 159                                i++;
 160                                name_first_parent_chain(p);
 161                        }
 162                }
 163        } while (i);
 164}
 165
 166static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 167{
 168        if (!commit->object.flags) {
 169                insert_by_date(commit, seen_p);
 170                return 1;
 171        }
 172        return 0;
 173}
 174
 175static void join_revs(struct commit_list **list_p,
 176                      struct commit_list **seen_p,
 177                      int num_rev, int extra)
 178{
 179        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 180        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 181
 182        while (*list_p) {
 183                struct commit_list *parents;
 184                int still_interesting = !!interesting(*list_p);
 185                struct commit *commit = pop_one_commit(list_p);
 186                int flags = commit->object.flags & all_mask;
 187
 188                if (!still_interesting && extra <= 0)
 189                        break;
 190
 191                mark_seen(commit, seen_p);
 192                if ((flags & all_revs) == all_revs)
 193                        flags |= UNINTERESTING;
 194                parents = commit->parents;
 195
 196                while (parents) {
 197                        struct commit *p = parents->item;
 198                        int this_flag = p->object.flags;
 199                        parents = parents->next;
 200                        if ((this_flag & flags) == flags)
 201                                continue;
 202                        if (!p->object.parsed)
 203                                parse_commit(p);
 204                        if (mark_seen(p, seen_p) && !still_interesting)
 205                                extra--;
 206                        p->object.flags |= flags;
 207                        insert_by_date(p, list_p);
 208                }
 209        }
 210
 211        /*
 212         * Postprocess to complete well-poisoning.
 213         *
 214         * At this point we have all the commits we have seen in
 215         * seen_p list (which happens to be sorted chronologically but
 216         * it does not really matter).  Mark anything that can be
 217         * reached from uninteresting commits not interesting.
 218         */
 219        for (;;) {
 220                int changed = 0;
 221                struct commit_list *s;
 222                for (s = *seen_p; s; s = s->next) {
 223                        struct commit *c = s->item;
 224                        struct commit_list *parents;
 225
 226                        if (((c->object.flags & all_revs) != all_revs) &&
 227                            !(c->object.flags & UNINTERESTING))
 228                                continue;
 229
 230                        /* The current commit is either a merge base or
 231                         * already uninteresting one.  Mark its parents
 232                         * as uninteresting commits _only_ if they are
 233                         * already parsed.  No reason to find new ones
 234                         * here.
 235                         */
 236                        parents = c->parents;
 237                        while (parents) {
 238                                struct commit *p = parents->item;
 239                                parents = parents->next;
 240                                if (!(p->object.flags & UNINTERESTING)) {
 241                                        p->object.flags |= UNINTERESTING;
 242                                        changed = 1;
 243                                }
 244                        }
 245                }
 246                if (!changed)
 247                        break;
 248        }
 249}
 250
 251static void show_one_commit(struct commit *commit, int no_name)
 252{
 253        char pretty[256], *cp;
 254        struct commit_name *name = commit->object.util;
 255        if (commit->object.parsed)
 256                pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
 257                                    pretty, sizeof(pretty));
 258        else
 259                strcpy(pretty, "(unavailable)");
 260        if (!strncmp(pretty, "[PATCH] ", 8))
 261                cp = pretty + 8;
 262        else
 263                cp = pretty;
 264
 265        if (!no_name) {
 266                if (name && name->head_name) {
 267                        printf("[%s", name->head_name);
 268                        if (name->generation) {
 269                                if (name->generation == 1)
 270                                        printf("^");
 271                                else
 272                                        printf("~%d", name->generation);
 273                        }
 274                        printf("] ");
 275                }
 276                else
 277                        printf("[%s] ",
 278                               find_unique_abbrev(commit->object.sha1, 7));
 279        }
 280        puts(cp);
 281}
 282
 283static char *ref_name[MAX_REVS + 1];
 284static int ref_name_cnt;
 285
 286static int compare_ref_name(const void *a_, const void *b_)
 287{
 288        const char * const*a = a_, * const*b = b_;
 289        return strcmp(*a, *b);
 290}
 291
 292static void sort_ref_range(int bottom, int top)
 293{
 294        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 295              compare_ref_name);
 296}
 297
 298static int append_ref(const char *refname, const unsigned char *sha1)
 299{
 300        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 301        if (!commit)
 302                return 0;
 303        if (MAX_REVS <= ref_name_cnt) {
 304                fprintf(stderr, "warning: ignoring %s; "
 305                        "cannot handle more than %d refs",
 306                        refname, MAX_REVS);
 307                return 0;
 308        }
 309        ref_name[ref_name_cnt++] = strdup(refname);
 310        ref_name[ref_name_cnt] = NULL;
 311        return 0;
 312}
 313
 314static int append_head_ref(const char *refname, const unsigned char *sha1)
 315{
 316        if (strncmp(refname, "refs/heads/", 11))
 317                return 0;
 318        return append_ref(refname + 11, sha1);
 319}
 320
 321static int append_tag_ref(const char *refname, const unsigned char *sha1)
 322{
 323        if (strncmp(refname, "refs/tags/", 10))
 324                return 0;
 325        return append_ref(refname + 5, sha1);
 326}
 327
 328static void snarf_refs(int head, int tag)
 329{
 330        if (head) {
 331                int orig_cnt = ref_name_cnt;
 332                for_each_ref(append_head_ref);
 333                sort_ref_range(orig_cnt, ref_name_cnt);
 334        }
 335        if (tag) {
 336                int orig_cnt = ref_name_cnt;
 337                for_each_ref(append_tag_ref);
 338                sort_ref_range(orig_cnt, ref_name_cnt);
 339        }
 340}
 341
 342static int rev_is_head(char *head_path, int headlen,
 343                       char *name,
 344                       unsigned char *head_sha1, unsigned char *sha1)
 345{
 346        int namelen;
 347        if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
 348                return 0;
 349        namelen = strlen(name);
 350        if ((headlen < namelen) ||
 351            memcmp(head_path + headlen - namelen, name, namelen))
 352                return 0;
 353        if (headlen == namelen ||
 354            head_path[headlen - namelen - 1] == '/')
 355                return 1;
 356        return 0;
 357}
 358
 359static int show_merge_base(struct commit_list *seen, int num_rev)
 360{
 361        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 362        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 363        int exit_status = 1;
 364
 365        while (seen) {
 366                struct commit *commit = pop_one_commit(&seen);
 367                int flags = commit->object.flags & all_mask;
 368                if (!(flags & UNINTERESTING) &&
 369                    ((flags & all_revs) == all_revs)) {
 370                        puts(sha1_to_hex(commit->object.sha1));
 371                        exit_status = 0;
 372                        commit->object.flags |= UNINTERESTING;
 373                }
 374        }
 375        return exit_status;
 376}
 377
 378static int show_independent(struct commit **rev,
 379                            int num_rev,
 380                            char **ref_name,
 381                            unsigned int *rev_mask)
 382{
 383        int i;
 384
 385        for (i = 0; i < num_rev; i++) {
 386                struct commit *commit = rev[i];
 387                unsigned int flag = rev_mask[i];
 388
 389                if (commit->object.flags == flag)
 390                        puts(sha1_to_hex(commit->object.sha1));
 391                commit->object.flags |= UNINTERESTING;
 392        }
 393        return 0;
 394}
 395
 396int main(int ac, char **av)
 397{
 398        struct commit *rev[MAX_REVS], *commit;
 399        struct commit_list *list = NULL, *seen = NULL;
 400        unsigned int rev_mask[MAX_REVS];
 401        int num_rev, i, extra = 0;
 402        int all_heads = 0, all_tags = 0;
 403        int all_mask, all_revs;
 404        char head_path[128];
 405        const char *head_path_p;
 406        int head_path_len;
 407        unsigned char head_sha1[20];
 408        int merge_base = 0;
 409        int independent = 0;
 410        int no_name = 0;
 411        int sha1_name = 0;
 412        int shown_merge_point = 0;
 413        int topo_order = 0;
 414
 415        setup_git_directory();
 416
 417        while (1 < ac && av[1][0] == '-') {
 418                char *arg = av[1];
 419                if (!strcmp(arg, "--all"))
 420                        all_heads = all_tags = 1;
 421                else if (!strcmp(arg, "--heads"))
 422                        all_heads = 1;
 423                else if (!strcmp(arg, "--tags"))
 424                        all_tags = 1;
 425                else if (!strcmp(arg, "--more"))
 426                        extra = 1;
 427                else if (!strcmp(arg, "--list"))
 428                        extra = -1;
 429                else if (!strcmp(arg, "--no-name"))
 430                        no_name = 1;
 431                else if (!strcmp(arg, "--sha1-name"))
 432                        sha1_name = 1;
 433                else if (!strncmp(arg, "--more=", 7))
 434                        extra = atoi(arg + 7);
 435                else if (!strcmp(arg, "--merge-base"))
 436                        merge_base = 1;
 437                else if (!strcmp(arg, "--independent"))
 438                        independent = 1;
 439                else if (!strcmp(arg, "--topo-order"))
 440                        topo_order = 1;
 441                else
 442                        usage(show_branch_usage);
 443                ac--; av++;
 444        }
 445        ac--; av++;
 446
 447        /* Only one of these is allowed */
 448        if (1 < independent + merge_base + (extra != 0))
 449                usage(show_branch_usage);
 450
 451        if (all_heads + all_tags)
 452                snarf_refs(all_heads, all_tags);
 453
 454        while (0 < ac) {
 455                unsigned char revkey[20];
 456                if (get_sha1(*av, revkey))
 457                        die("bad sha1 reference %s", *av);
 458                append_ref(*av, revkey);
 459                ac--; av++;
 460        }
 461
 462        /* If still no revs, then add heads */
 463        if (!ref_name_cnt)
 464                snarf_refs(1, 0);
 465
 466        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 467                unsigned char revkey[20];
 468                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 469
 470                if (MAX_REVS <= num_rev)
 471                        die("cannot handle more than %d revs.", MAX_REVS);
 472                if (get_sha1(ref_name[num_rev], revkey))
 473                        usage(show_branch_usage);
 474                commit = lookup_commit_reference(revkey);
 475                if (!commit)
 476                        die("cannot find commit %s (%s)",
 477                            ref_name[num_rev], revkey);
 478                parse_commit(commit);
 479                mark_seen(commit, &seen);
 480
 481                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 482                 * and so on.  REV_SHIFT bits from bit 0 are used for
 483                 * internal bookkeeping.
 484                 */
 485                commit->object.flags |= flag;
 486                if (commit->object.flags == flag)
 487                        insert_by_date(commit, &list);
 488                rev[num_rev] = commit;
 489        }
 490        for (i = 0; i < num_rev; i++)
 491                rev_mask[i] = rev[i]->object.flags;
 492
 493        if (0 <= extra)
 494                join_revs(&list, &seen, num_rev, extra);
 495
 496        head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 497        if (head_path_p) {
 498                head_path_len = strlen(head_path_p);
 499                memcpy(head_path, head_path_p, head_path_len + 1);
 500        }
 501        else {
 502                head_path_len = 0;
 503                head_path[0] = 0;
 504        }
 505
 506        if (merge_base)
 507                return show_merge_base(seen, num_rev);
 508
 509        if (independent)
 510                return show_independent(rev, num_rev, ref_name, rev_mask);
 511
 512        /* Show list; --more=-1 means list-only */
 513        if (1 < num_rev || extra < 0) {
 514                for (i = 0; i < num_rev; i++) {
 515                        int j;
 516                        int is_head = rev_is_head(head_path,
 517                                                  head_path_len,
 518                                                  ref_name[i],
 519                                                  head_sha1,
 520                                                  rev[i]->object.sha1);
 521                        if (extra < 0)
 522                                printf("%c [%s] ",
 523                                       is_head ? '*' : ' ', ref_name[i]);
 524                        else {
 525                                for (j = 0; j < i; j++)
 526                                        putchar(' ');
 527                                printf("%c [%s] ",
 528                                       is_head ? '*' : '!', ref_name[i]);
 529                        }
 530                        /* header lines never need name */
 531                        show_one_commit(rev[i], 1);
 532                }
 533                if (0 <= extra) {
 534                        for (i = 0; i < num_rev; i++)
 535                                putchar('-');
 536                        putchar('\n');
 537                }
 538        }
 539        if (extra < 0)
 540                exit(0);
 541
 542        /* Sort topologically */
 543        if (topo_order)
 544                sort_in_topological_order(&seen);
 545
 546        /* Give names to commits */
 547        if (!sha1_name && !no_name)
 548                name_commits(seen, rev, ref_name, num_rev);
 549
 550        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 551        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 552
 553        while (seen) {
 554                struct commit *commit = pop_one_commit(&seen);
 555                int this_flag = commit->object.flags;
 556
 557                shown_merge_point |= ((this_flag & all_revs) == all_revs);
 558
 559                if (1 < num_rev) {
 560                        for (i = 0; i < num_rev; i++)
 561                                putchar((this_flag & (1u << (i + REV_SHIFT)))
 562                                        ? '+' : ' ');
 563                        putchar(' ');
 564                }
 565                show_one_commit(commit, no_name);
 566
 567                if (shown_merge_point && --extra < 0)
 568                        break;
 569        }
 570        return 0;
 571}