Andrew's git / gitweb.git / show-branch.c
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show-branch.con commit show-branch: optionally use unique prefix as name. (013f276)
   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                struct commit *commit = pop_one_commit(list_p);
 185                int flags = commit->object.flags & all_mask;
 186                int still_interesting = !!interesting(*list_p);
 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                        parse_commit(p);
 203                        if (mark_seen(p, seen_p) && !still_interesting)
 204                                extra--;
 205                        p->object.flags |= flags;
 206                        insert_by_date(p, list_p);
 207                }
 208        }
 209}
 210
 211static void show_one_commit(struct commit *commit, int no_name)
 212{
 213        char pretty[128], *cp;
 214        struct commit_name *name = commit->object.util;
 215        if (commit->object.parsed)
 216                pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
 217                                    pretty, sizeof(pretty));
 218        else
 219                strcpy(pretty, "(unavailable)");
 220        if (!strncmp(pretty, "[PATCH] ", 8))
 221                cp = pretty + 8;
 222        else
 223                cp = pretty;
 224
 225        if (!no_name) {
 226                if (name && name->head_name) {
 227                        printf("[%s", name->head_name);
 228                        if (name->generation) {
 229                                if (name->generation == 1)
 230                                        printf("^");
 231                                else
 232                                        printf("~%d", name->generation);
 233                        }
 234                        printf("] ");
 235                }
 236                else
 237                        printf("[%s] ",
 238                               find_unique_abbrev(commit->object.sha1, 7));
 239        }
 240        puts(cp);
 241}
 242
 243static char *ref_name[MAX_REVS + 1];
 244static int ref_name_cnt;
 245
 246static int compare_ref_name(const void *a_, const void *b_)
 247{
 248        const char * const*a = a_, * const*b = b_;
 249        return strcmp(*a, *b);
 250}
 251
 252static void sort_ref_range(int bottom, int top)
 253{
 254        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 255              compare_ref_name);
 256}
 257
 258static int append_ref(const char *refname, const unsigned char *sha1)
 259{
 260        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 261        if (!commit)
 262                return 0;
 263        if (MAX_REVS < ref_name_cnt) {
 264                fprintf(stderr, "warning: ignoring %s; "
 265                        "cannot handle more than %d refs",
 266                        refname, MAX_REVS);
 267                return 0;
 268        }
 269        ref_name[ref_name_cnt++] = strdup(refname);
 270        ref_name[ref_name_cnt] = NULL;
 271        return 0;
 272}
 273
 274static int append_head_ref(const char *refname, const unsigned char *sha1)
 275{
 276        if (strncmp(refname, "refs/heads/", 11))
 277                return 0;
 278        return append_ref(refname + 11, sha1);
 279}
 280
 281static int append_tag_ref(const char *refname, const unsigned char *sha1)
 282{
 283        if (strncmp(refname, "refs/tags/", 10))
 284                return 0;
 285        return append_ref(refname + 5, sha1);
 286}
 287
 288static void snarf_refs(int head, int tag)
 289{
 290        if (head) {
 291                int orig_cnt = ref_name_cnt;
 292                for_each_ref(append_head_ref);
 293                sort_ref_range(orig_cnt, ref_name_cnt);
 294        }
 295        if (tag) {
 296                int orig_cnt = ref_name_cnt;
 297                for_each_ref(append_tag_ref);
 298                sort_ref_range(orig_cnt, ref_name_cnt);
 299        }
 300}
 301
 302static int rev_is_head(char *head_path, int headlen,
 303                       char *name,
 304                       unsigned char *head_sha1, unsigned char *sha1)
 305{
 306        int namelen;
 307        if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
 308                return 0;
 309        namelen = strlen(name);
 310        if ((headlen < namelen) ||
 311            memcmp(head_path + headlen - namelen, name, namelen))
 312                return 0;
 313        if (headlen == namelen ||
 314            head_path[headlen - namelen - 1] == '/')
 315                return 1;
 316        return 0;
 317}
 318
 319static int show_merge_base(struct commit_list *seen, int num_rev)
 320{
 321        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 322        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 323        int exit_status = 1;
 324
 325        while (seen) {
 326                struct commit *commit = pop_one_commit(&seen);
 327                int flags = commit->object.flags & all_mask;
 328                if (!(flags & UNINTERESTING) &&
 329                    ((flags & all_revs) == all_revs)) {
 330                        puts(sha1_to_hex(commit->object.sha1));
 331                        exit_status = 0;
 332                        commit->object.flags |= UNINTERESTING;
 333                }
 334        }
 335        return exit_status;
 336}
 337
 338static int show_independent(struct commit **rev,
 339                            int num_rev,
 340                            char **ref_name,
 341                            unsigned int *rev_mask)
 342{
 343        int i;
 344
 345        for (i = 0; i < num_rev; i++) {
 346                struct commit *commit = rev[i];
 347                unsigned int flag = rev_mask[i];
 348
 349                if (commit->object.flags == flag)
 350                        puts(sha1_to_hex(commit->object.sha1));
 351                commit->object.flags |= UNINTERESTING;
 352        }
 353        return 0;
 354}
 355
 356int main(int ac, char **av)
 357{
 358        struct commit *rev[MAX_REVS], *commit;
 359        struct commit_list *list = NULL, *seen = NULL;
 360        unsigned int rev_mask[MAX_REVS];
 361        int num_rev, i, extra = 0;
 362        int all_heads = 0, all_tags = 0;
 363        int all_mask, all_revs, shown_merge_point;
 364        char head_path[128];
 365        const char *head_path_p;
 366        int head_path_len;
 367        unsigned char head_sha1[20];
 368        int merge_base = 0;
 369        int independent = 0;
 370        int no_name = 0;
 371        int sha1_name = 0;
 372
 373        setup_git_directory();
 374
 375        while (1 < ac && av[1][0] == '-') {
 376                char *arg = av[1];
 377                if (!strcmp(arg, "--all"))
 378                        all_heads = all_tags = 1;
 379                else if (!strcmp(arg, "--heads"))
 380                        all_heads = 1;
 381                else if (!strcmp(arg, "--tags"))
 382                        all_tags = 1;
 383                else if (!strcmp(arg, "--more"))
 384                        extra = 1;
 385                else if (!strcmp(arg, "--list"))
 386                        extra = -1;
 387                else if (!strcmp(arg, "--no-name"))
 388                        no_name = 1;
 389                else if (!strcmp(arg, "--sha1-name"))
 390                        sha1_name = 1;
 391                else if (!strncmp(arg, "--more=", 7))
 392                        extra = atoi(arg + 7);
 393                else if (!strcmp(arg, "--merge-base"))
 394                        merge_base = 1;
 395                else if (!strcmp(arg, "--independent"))
 396                        independent = 1;
 397                else
 398                        usage(show_branch_usage);
 399                ac--; av++;
 400        }
 401        ac--; av++;
 402
 403        /* Only one of these is allowed */
 404        if (1 < independent + merge_base + (extra != 0))
 405                usage(show_branch_usage);
 406
 407        if (all_heads + all_tags)
 408                snarf_refs(all_heads, all_tags);
 409
 410        while (0 < ac) {
 411                unsigned char revkey[20];
 412                if (get_sha1(*av, revkey))
 413                        die("bad sha1 reference %s", *av);
 414                append_ref(*av, revkey);
 415                ac--; av++;
 416        }
 417
 418        /* If still no revs, then add heads */
 419        if (!ref_name_cnt)
 420                snarf_refs(1, 0);
 421
 422        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 423                unsigned char revkey[20];
 424                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 425
 426                if (MAX_REVS <= num_rev)
 427                        die("cannot handle more than %d revs.", MAX_REVS);
 428                if (get_sha1(ref_name[num_rev], revkey))
 429                        usage(show_branch_usage);
 430                commit = lookup_commit_reference(revkey);
 431                if (!commit)
 432                        die("cannot find commit %s (%s)",
 433                            ref_name[num_rev], revkey);
 434                parse_commit(commit);
 435                mark_seen(commit, &seen);
 436
 437                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 438                 * and so on.  REV_SHIFT bits from bit 0 are used for
 439                 * internal bookkeeping.
 440                 */
 441                commit->object.flags |= flag;
 442                if (commit->object.flags == flag)
 443                        insert_by_date(commit, &list);
 444                rev[num_rev] = commit;
 445        }
 446        for (i = 0; i < num_rev; i++)
 447                rev_mask[i] = rev[i]->object.flags;
 448
 449        if (0 <= extra)
 450                join_revs(&list, &seen, num_rev, extra);
 451
 452        head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 453        if (head_path_p) {
 454                head_path_len = strlen(head_path_p);
 455                memcpy(head_path, head_path_p, head_path_len + 1);
 456        }
 457        else {
 458                head_path_len = 0;
 459                head_path[0] = 0;
 460        }
 461
 462        if (merge_base)
 463                return show_merge_base(seen, num_rev);
 464
 465        if (independent)
 466                return show_independent(rev, num_rev, ref_name, rev_mask);
 467
 468        /* Show list; --more=-1 means list-only */
 469        if (1 < num_rev || extra < 0) {
 470                for (i = 0; i < num_rev; i++) {
 471                        int j;
 472                        int is_head = rev_is_head(head_path,
 473                                                  head_path_len,
 474                                                  ref_name[i],
 475                                                  head_sha1,
 476                                                  rev[i]->object.sha1);
 477                        if (extra < 0)
 478                                printf("%c [%s] ",
 479                                       is_head ? '*' : ' ', ref_name[i]);
 480                        else {
 481                                for (j = 0; j < i; j++)
 482                                        putchar(' ');
 483                                printf("%c [%s] ",
 484                                       is_head ? '*' : '!', ref_name[i]);
 485                        }
 486                        /* header lines never need name */
 487                        show_one_commit(rev[i], 1);
 488                }
 489                if (0 <= extra) {
 490                        for (i = 0; i < num_rev; i++)
 491                                putchar('-');
 492                        putchar('\n');
 493                }
 494        }
 495        if (extra < 0)
 496                exit(0);
 497
 498        /* Sort topologically */
 499        sort_in_topological_order(&seen);
 500
 501        /* Give names to commits */
 502        if (!sha1_name && !no_name)
 503                name_commits(seen, rev, ref_name, num_rev);
 504
 505        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 506        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 507        shown_merge_point = 0;
 508
 509        while (seen) {
 510                struct commit *commit = pop_one_commit(&seen);
 511                int this_flag = commit->object.flags;
 512                int is_merge_point = (this_flag & all_revs) == all_revs;
 513
 514                if (is_merge_point)
 515                        shown_merge_point = 1;
 516
 517                if (1 < num_rev) {
 518                        for (i = 0; i < num_rev; i++)
 519                                putchar((this_flag & (1u << (i + REV_SHIFT)))
 520                                        ? '+' : ' ');
 521                        putchar(' ');
 522                }
 523                show_one_commit(commit, no_name);
 524                if (shown_merge_point && is_merge_point)
 525                        if (--extra < 0)
 526                                break;
 527        }
 528        return 0;
 529}