Andrew's git / gitweb.git / commit.c
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commit.con commit annotate: Support annotation of files on other revisions. (5fcab3d)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4
   5int save_commit_buffer = 1;
   6
   7struct sort_node
   8{
   9        /*
  10         * the number of children of the associated commit
  11         * that also occur in the list being sorted.
  12         */
  13        unsigned int indegree;
  14
  15        /*
  16         * reference to original list item that we will re-use
  17         * on output.
  18         */
  19        struct commit_list * list_item;
  20
  21};
  22
  23const char *commit_type = "commit";
  24
  25enum cmit_fmt get_commit_format(const char *arg)
  26{
  27        if (!*arg)
  28                return CMIT_FMT_DEFAULT;
  29        if (!strcmp(arg, "=raw"))
  30                return CMIT_FMT_RAW;
  31        if (!strcmp(arg, "=medium"))
  32                return CMIT_FMT_MEDIUM;
  33        if (!strcmp(arg, "=short"))
  34                return CMIT_FMT_SHORT;
  35        if (!strcmp(arg, "=full"))
  36                return CMIT_FMT_FULL;
  37        if (!strcmp(arg, "=fuller"))
  38                return CMIT_FMT_FULLER;
  39        if (!strcmp(arg, "=oneline"))
  40                return CMIT_FMT_ONELINE;
  41        die("invalid --pretty format");
  42}
  43
  44static struct commit *check_commit(struct object *obj,
  45                                   const unsigned char *sha1,
  46                                   int quiet)
  47{
  48        if (obj->type != commit_type) {
  49                if (!quiet)
  50                        error("Object %s is a %s, not a commit",
  51                              sha1_to_hex(sha1), obj->type);
  52                return NULL;
  53        }
  54        return (struct commit *) obj;
  55}
  56
  57struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  58                                              int quiet)
  59{
  60        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  61
  62        if (!obj)
  63                return NULL;
  64        return check_commit(obj, sha1, quiet);
  65}
  66
  67struct commit *lookup_commit_reference(const unsigned char *sha1)
  68{
  69        return lookup_commit_reference_gently(sha1, 0);
  70}
  71
  72struct commit *lookup_commit(const unsigned char *sha1)
  73{
  74        struct object *obj = lookup_object(sha1);
  75        if (!obj) {
  76                struct commit *ret = xmalloc(sizeof(struct commit));
  77                memset(ret, 0, sizeof(struct commit));
  78                created_object(sha1, &ret->object);
  79                ret->object.type = commit_type;
  80                return ret;
  81        }
  82        if (!obj->type)
  83                obj->type = commit_type;
  84        return check_commit(obj, sha1, 0);
  85}
  86
  87static unsigned long parse_commit_date(const char *buf)
  88{
  89        unsigned long date;
  90
  91        if (memcmp(buf, "author", 6))
  92                return 0;
  93        while (*buf++ != '\n')
  94                /* nada */;
  95        if (memcmp(buf, "committer", 9))
  96                return 0;
  97        while (*buf++ != '>')
  98                /* nada */;
  99        date = strtoul(buf, NULL, 10);
 100        if (date == ULONG_MAX)
 101                date = 0;
 102        return date;
 103}
 104
 105static struct commit_graft {
 106        unsigned char sha1[20];
 107        int nr_parent;
 108        unsigned char parent[0][20]; /* more */
 109} **commit_graft;
 110static int commit_graft_alloc, commit_graft_nr;
 111
 112static int commit_graft_pos(const unsigned char *sha1)
 113{
 114        int lo, hi;
 115        lo = 0;
 116        hi = commit_graft_nr;
 117        while (lo < hi) {
 118                int mi = (lo + hi) / 2;
 119                struct commit_graft *graft = commit_graft[mi];
 120                int cmp = memcmp(sha1, graft->sha1, 20);
 121                if (!cmp)
 122                        return mi;
 123                if (cmp < 0)
 124                        hi = mi;
 125                else
 126                        lo = mi + 1;
 127        }
 128        return -lo - 1;
 129}
 130
 131static void prepare_commit_graft(void)
 132{
 133        char *graft_file = get_graft_file();
 134        FILE *fp = fopen(graft_file, "r");
 135        char buf[1024];
 136        if (!fp) {
 137                commit_graft = (struct commit_graft **) "hack";
 138                return;
 139        }
 140        while (fgets(buf, sizeof(buf), fp)) {
 141                /* The format is just "Commit Parent1 Parent2 ...\n" */
 142                int len = strlen(buf);
 143                int i;
 144                struct commit_graft *graft = NULL;
 145
 146                if (buf[len-1] == '\n')
 147                        buf[--len] = 0;
 148                if (buf[0] == '#')
 149                        continue;
 150                if ((len + 1) % 41) {
 151                bad_graft_data:
 152                        error("bad graft data: %s", buf);
 153                        free(graft);
 154                        continue;
 155                }
 156                i = (len + 1) / 41 - 1;
 157                graft = xmalloc(sizeof(*graft) + 20 * i);
 158                graft->nr_parent = i;
 159                if (get_sha1_hex(buf, graft->sha1))
 160                        goto bad_graft_data;
 161                for (i = 40; i < len; i += 41) {
 162                        if (buf[i] != ' ')
 163                                goto bad_graft_data;
 164                        if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 165                                goto bad_graft_data;
 166                }
 167                i = commit_graft_pos(graft->sha1);
 168                if (0 <= i) {
 169                        error("duplicate graft data: %s", buf);
 170                        free(graft);
 171                        continue;
 172                }
 173                i = -i - 1;
 174                if (commit_graft_alloc <= ++commit_graft_nr) {
 175                        commit_graft_alloc = alloc_nr(commit_graft_alloc);
 176                        commit_graft = xrealloc(commit_graft,
 177                                                sizeof(*commit_graft) *
 178                                                commit_graft_alloc);
 179                }
 180                if (i < commit_graft_nr)
 181                        memmove(commit_graft + i + 1,
 182                                commit_graft + i,
 183                                (commit_graft_nr - i - 1) *
 184                                sizeof(*commit_graft));
 185                commit_graft[i] = graft;
 186        }
 187        fclose(fp);
 188}
 189
 190static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 191{
 192        int pos;
 193        if (!commit_graft)
 194                prepare_commit_graft();
 195        pos = commit_graft_pos(sha1);
 196        if (pos < 0)
 197                return NULL;
 198        return commit_graft[pos];
 199}
 200
 201int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 202{
 203        char *bufptr = buffer;
 204        unsigned char parent[20];
 205        struct commit_list **pptr;
 206        struct commit_graft *graft;
 207        unsigned n_refs = 0;
 208
 209        if (item->object.parsed)
 210                return 0;
 211        item->object.parsed = 1;
 212        if (memcmp(bufptr, "tree ", 5))
 213                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 214        if (get_sha1_hex(bufptr + 5, parent) < 0)
 215                return error("bad tree pointer in commit %s",
 216                             sha1_to_hex(item->object.sha1));
 217        item->tree = lookup_tree(parent);
 218        if (item->tree)
 219                n_refs++;
 220        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 221        pptr = &item->parents;
 222
 223        graft = lookup_commit_graft(item->object.sha1);
 224        while (!memcmp(bufptr, "parent ", 7)) {
 225                struct commit *new_parent;
 226
 227                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 228                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 229                bufptr += 48;
 230                if (graft)
 231                        continue;
 232                new_parent = lookup_commit(parent);
 233                if (new_parent) {
 234                        pptr = &commit_list_insert(new_parent, pptr)->next;
 235                        n_refs++;
 236                }
 237        }
 238        if (graft) {
 239                int i;
 240                struct commit *new_parent;
 241                for (i = 0; i < graft->nr_parent; i++) {
 242                        new_parent = lookup_commit(graft->parent[i]);
 243                        if (!new_parent)
 244                                continue;
 245                        pptr = &commit_list_insert(new_parent, pptr)->next;
 246                        n_refs++;
 247                }
 248        }
 249        item->date = parse_commit_date(bufptr);
 250
 251        if (track_object_refs) {
 252                unsigned i = 0;
 253                struct commit_list *p;
 254                struct object_refs *refs = alloc_object_refs(n_refs);
 255                if (item->tree)
 256                        refs->ref[i++] = &item->tree->object;
 257                for (p = item->parents; p; p = p->next)
 258                        refs->ref[i++] = &p->item->object;
 259                set_object_refs(&item->object, refs);
 260        }
 261
 262        return 0;
 263}
 264
 265int parse_commit(struct commit *item)
 266{
 267        char type[20];
 268        void *buffer;
 269        unsigned long size;
 270        int ret;
 271
 272        if (item->object.parsed)
 273                return 0;
 274        buffer = read_sha1_file(item->object.sha1, type, &size);
 275        if (!buffer)
 276                return error("Could not read %s",
 277                             sha1_to_hex(item->object.sha1));
 278        if (strcmp(type, commit_type)) {
 279                free(buffer);
 280                return error("Object %s not a commit",
 281                             sha1_to_hex(item->object.sha1));
 282        }
 283        ret = parse_commit_buffer(item, buffer, size);
 284        if (save_commit_buffer && !ret) {
 285                item->buffer = buffer;
 286                return 0;
 287        }
 288        free(buffer);
 289        return ret;
 290}
 291
 292struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 293{
 294        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 295        new_list->item = item;
 296        new_list->next = *list_p;
 297        *list_p = new_list;
 298        return new_list;
 299}
 300
 301void free_commit_list(struct commit_list *list)
 302{
 303        while (list) {
 304                struct commit_list *temp = list;
 305                list = temp->next;
 306                free(temp);
 307        }
 308}
 309
 310struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 311{
 312        struct commit_list **pp = list;
 313        struct commit_list *p;
 314        while ((p = *pp) != NULL) {
 315                if (p->item->date < item->date) {
 316                        break;
 317                }
 318                pp = &p->next;
 319        }
 320        return commit_list_insert(item, pp);
 321}
 322
 323        
 324void sort_by_date(struct commit_list **list)
 325{
 326        struct commit_list *ret = NULL;
 327        while (*list) {
 328                insert_by_date((*list)->item, &ret);
 329                *list = (*list)->next;
 330        }
 331        *list = ret;
 332}
 333
 334struct commit *pop_most_recent_commit(struct commit_list **list,
 335                                      unsigned int mark)
 336{
 337        struct commit *ret = (*list)->item;
 338        struct commit_list *parents = ret->parents;
 339        struct commit_list *old = *list;
 340
 341        *list = (*list)->next;
 342        free(old);
 343
 344        while (parents) {
 345                struct commit *commit = parents->item;
 346                parse_commit(commit);
 347                if (!(commit->object.flags & mark)) {
 348                        commit->object.flags |= mark;
 349                        insert_by_date(commit, list);
 350                }
 351                parents = parents->next;
 352        }
 353        return ret;
 354}
 355
 356void clear_commit_marks(struct commit *commit, unsigned int mark)
 357{
 358        struct commit_list *parents;
 359
 360        parents = commit->parents;
 361        commit->object.flags &= ~mark;
 362        while (parents) {
 363                struct commit *parent = parents->item;
 364                if (parent && parent->object.parsed &&
 365                    (parent->object.flags & mark))
 366                        clear_commit_marks(parent, mark);
 367                parents = parents->next;
 368        }
 369}
 370
 371/*
 372 * Generic support for pretty-printing the header
 373 */
 374static int get_one_line(const char *msg, unsigned long len)
 375{
 376        int ret = 0;
 377
 378        while (len--) {
 379                char c = *msg++;
 380                ret++;
 381                if (c == '\n')
 382                        break;
 383                if (!c)
 384                        return 0;
 385        }
 386        return ret;
 387}
 388
 389static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 390{
 391        char *date;
 392        int namelen;
 393        unsigned long time;
 394        int tz, ret;
 395        const char *filler = "    ";
 396
 397        if (fmt == CMIT_FMT_ONELINE)
 398                return 0;
 399        date = strchr(line, '>');
 400        if (!date)
 401                return 0;
 402        namelen = ++date - line;
 403        time = strtoul(date, &date, 10);
 404        tz = strtol(date, NULL, 10);
 405
 406        ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 407                      (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 408                      filler, namelen, line);
 409        switch (fmt) {
 410        case CMIT_FMT_MEDIUM:
 411                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 412                break;
 413        case CMIT_FMT_FULLER:
 414                ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 415                break;
 416        default:
 417                /* notin' */
 418                break;
 419        }
 420        return ret;
 421}
 422
 423static int is_empty_line(const char *line, int len)
 424{
 425        while (len && isspace(line[len-1]))
 426                len--;
 427        return !len;
 428}
 429
 430static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 431{
 432        struct commit_list *parent = commit->parents;
 433        int offset;
 434
 435        if ((fmt == CMIT_FMT_ONELINE) || !parent || !parent->next)
 436                return 0;
 437
 438        offset = sprintf(buf, "Merge:");
 439
 440        while (parent) {
 441                struct commit *p = parent->item;
 442                const char *hex = abbrev
 443                        ? find_unique_abbrev(p->object.sha1, abbrev)
 444                        : sha1_to_hex(p->object.sha1);
 445                char *dots = (abbrev && strlen(hex) != 40) ? "..." : "";
 446                parent = parent->next;
 447
 448                offset += sprintf(buf + offset, " %s%s", hex, dots);
 449        }
 450        buf[offset++] = '\n';
 451        return offset;
 452}
 453
 454unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit, unsigned long len, char *buf, unsigned long space, int abbrev)
 455{
 456        int hdr = 1, body = 0;
 457        unsigned long offset = 0;
 458        int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 459        int parents_shown = 0;
 460        const char *msg = commit->buffer;
 461
 462        for (;;) {
 463                const char *line = msg;
 464                int linelen = get_one_line(msg, len);
 465
 466                if (!linelen)
 467                        break;
 468
 469                /*
 470                 * We want some slop for indentation and a possible
 471                 * final "...". Thus the "+ 20".
 472                 */
 473                if (offset + linelen + 20 > space) {
 474                        memcpy(buf + offset, "    ...\n", 8);
 475                        offset += 8;
 476                        break;
 477                }
 478
 479                msg += linelen;
 480                len -= linelen;
 481                if (hdr) {
 482                        if (linelen == 1) {
 483                                hdr = 0;
 484                                if (fmt != CMIT_FMT_ONELINE)
 485                                        buf[offset++] = '\n';
 486                                continue;
 487                        }
 488                        if (fmt == CMIT_FMT_RAW) {
 489                                memcpy(buf + offset, line, linelen);
 490                                offset += linelen;
 491                                continue;
 492                        }
 493                        if (!memcmp(line, "parent ", 7)) {
 494                                if (linelen != 48)
 495                                        die("bad parent line in commit");
 496                                continue;
 497                        }
 498
 499                        if (!parents_shown) {
 500                                offset += add_merge_info(fmt, buf + offset,
 501                                                         commit, abbrev);
 502                                parents_shown = 1;
 503                                continue;
 504                        }
 505                        /*
 506                         * MEDIUM == DEFAULT shows only author with dates.
 507                         * FULL shows both authors but not dates.
 508                         * FULLER shows both authors and dates.
 509                         */
 510                        if (!memcmp(line, "author ", 7))
 511                                offset += add_user_info("Author", fmt,
 512                                                        buf + offset,
 513                                                        line + 7);
 514                        if (!memcmp(line, "committer ", 10) &&
 515                            (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 516                                offset += add_user_info("Commit", fmt,
 517                                                        buf + offset,
 518                                                        line + 10);
 519                        continue;
 520                }
 521
 522                if (is_empty_line(line, linelen)) {
 523                        if (!body)
 524                                continue;
 525                        if (fmt == CMIT_FMT_SHORT)
 526                                break;
 527                } else {
 528                        body = 1;
 529                }
 530
 531                memset(buf + offset, ' ', indent);
 532                memcpy(buf + offset + indent, line, linelen);
 533                offset += linelen + indent;
 534                if (fmt == CMIT_FMT_ONELINE)
 535                        break;
 536        }
 537        if (fmt == CMIT_FMT_ONELINE) {
 538                /* We do not want the terminating newline */
 539                if (buf[offset - 1] == '\n')
 540                        offset--;
 541        }
 542        else {
 543                /* Make sure there is an EOLN */
 544                if (buf[offset - 1] != '\n')
 545                        buf[offset++] = '\n';
 546        }
 547        buf[offset] = '\0';
 548        return offset;
 549}
 550
 551struct commit *pop_commit(struct commit_list **stack)
 552{
 553        struct commit_list *top = *stack;
 554        struct commit *item = top ? top->item : NULL;
 555
 556        if (top) {
 557                *stack = top->next;
 558                free(top);
 559        }
 560        return item;
 561}
 562
 563int count_parents(struct commit * commit)
 564{
 565        int count = 0;
 566        struct commit_list * parents = commit->parents;
 567        for (count=0;parents; parents=parents->next,count++)
 568          ;
 569        return count;
 570}
 571
 572/*
 573 * Performs an in-place topological sort on the list supplied.
 574 */
 575void sort_in_topological_order(struct commit_list ** list, int lifo)
 576{
 577        struct commit_list * next = *list;
 578        struct commit_list * work = NULL, **insert;
 579        struct commit_list ** pptr = list;
 580        struct sort_node * nodes;
 581        struct sort_node * next_nodes;
 582        int count = 0;
 583
 584        /* determine the size of the list */
 585        while (next) {
 586                next = next->next;
 587                count++;
 588        }
 589        
 590        if (!count)
 591                return;
 592        /* allocate an array to help sort the list */
 593        nodes = xcalloc(count, sizeof(*nodes));
 594        /* link the list to the array */
 595        next_nodes = nodes;
 596        next=*list;
 597        while (next) {
 598                next_nodes->list_item = next;
 599                next->item->object.util = next_nodes;
 600                next_nodes++;
 601                next = next->next;
 602        }
 603        /* update the indegree */
 604        next=*list;
 605        while (next) {
 606                struct commit_list * parents = next->item->parents;
 607                while (parents) {
 608                        struct commit * parent=parents->item;
 609                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 610                        
 611                        if (pn)
 612                                pn->indegree++;
 613                        parents=parents->next;
 614                }
 615                next=next->next;
 616        }
 617        /* 
 618         * find the tips
 619         *
 620         * tips are nodes not reachable from any other node in the list 
 621         * 
 622         * the tips serve as a starting set for the work queue.
 623         */
 624        next=*list;
 625        insert = &work;
 626        while (next) {
 627                struct sort_node * node = (struct sort_node *)next->item->object.util;
 628
 629                if (node->indegree == 0) {
 630                        insert = &commit_list_insert(next->item, insert)->next;
 631                }
 632                next=next->next;
 633        }
 634
 635        /* process the list in topological order */
 636        if (!lifo)
 637                sort_by_date(&work);
 638        while (work) {
 639                struct commit * work_item = pop_commit(&work);
 640                struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 641                struct commit_list * parents = work_item->parents;
 642
 643                while (parents) {
 644                        struct commit * parent=parents->item;
 645                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 646                        
 647                        if (pn) {
 648                                /* 
 649                                 * parents are only enqueued for emission 
 650                                 * when all their children have been emitted thereby
 651                                 * guaranteeing topological order.
 652                                 */
 653                                pn->indegree--;
 654                                if (!pn->indegree) {
 655                                        if (!lifo)
 656                                                insert_by_date(parent, &work);
 657                                        else
 658                                                commit_list_insert(parent, &work);
 659                                }
 660                        }
 661                        parents=parents->next;
 662                }
 663                /*
 664                 * work_item is a commit all of whose children
 665                 * have already been emitted. we can emit it now.
 666                 */
 667                *pptr = work_node->list_item;
 668                pptr = &(*pptr)->next;
 669                *pptr = NULL;
 670                work_item->object.util = NULL;
 671        }
 672        free(nodes);
 673}