Andrew's git / gitweb.git / commit.c
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commit.con commit Merge branch 'jc/cache-tree' into next (2c4c17f)
   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, "=email"))
  40                return CMIT_FMT_EMAIL;
  41        if (!strcmp(arg, "=oneline"))
  42                return CMIT_FMT_ONELINE;
  43        die("invalid --pretty format");
  44}
  45
  46static struct commit *check_commit(struct object *obj,
  47                                   const unsigned char *sha1,
  48                                   int quiet)
  49{
  50        if (obj->type != commit_type) {
  51                if (!quiet)
  52                        error("Object %s is a %s, not a commit",
  53                              sha1_to_hex(sha1), obj->type);
  54                return NULL;
  55        }
  56        return (struct commit *) obj;
  57}
  58
  59struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  60                                              int quiet)
  61{
  62        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  63
  64        if (!obj)
  65                return NULL;
  66        return check_commit(obj, sha1, quiet);
  67}
  68
  69struct commit *lookup_commit_reference(const unsigned char *sha1)
  70{
  71        return lookup_commit_reference_gently(sha1, 0);
  72}
  73
  74struct commit *lookup_commit(const unsigned char *sha1)
  75{
  76        struct object *obj = lookup_object(sha1);
  77        if (!obj) {
  78                struct commit *ret = xcalloc(1, sizeof(struct commit));
  79                created_object(sha1, &ret->object);
  80                ret->object.type = commit_type;
  81                return ret;
  82        }
  83        if (!obj->type)
  84                obj->type = commit_type;
  85        return check_commit(obj, sha1, 0);
  86}
  87
  88static unsigned long parse_commit_date(const char *buf)
  89{
  90        unsigned long date;
  91
  92        if (memcmp(buf, "author", 6))
  93                return 0;
  94        while (*buf++ != '\n')
  95                /* nada */;
  96        if (memcmp(buf, "committer", 9))
  97                return 0;
  98        while (*buf++ != '>')
  99                /* nada */;
 100        date = strtoul(buf, NULL, 10);
 101        if (date == ULONG_MAX)
 102                date = 0;
 103        return date;
 104}
 105
 106static struct commit_graft **commit_graft;
 107static int commit_graft_alloc, commit_graft_nr;
 108
 109static int commit_graft_pos(const unsigned char *sha1)
 110{
 111        int lo, hi;
 112        lo = 0;
 113        hi = commit_graft_nr;
 114        while (lo < hi) {
 115                int mi = (lo + hi) / 2;
 116                struct commit_graft *graft = commit_graft[mi];
 117                int cmp = memcmp(sha1, graft->sha1, 20);
 118                if (!cmp)
 119                        return mi;
 120                if (cmp < 0)
 121                        hi = mi;
 122                else
 123                        lo = mi + 1;
 124        }
 125        return -lo - 1;
 126}
 127
 128int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 129{
 130        int pos = commit_graft_pos(graft->sha1);
 131        
 132        if (0 <= pos) {
 133                if (ignore_dups)
 134                        free(graft);
 135                else {
 136                        free(commit_graft[pos]);
 137                        commit_graft[pos] = graft;
 138                }
 139                return 1;
 140        }
 141        pos = -pos - 1;
 142        if (commit_graft_alloc <= ++commit_graft_nr) {
 143                commit_graft_alloc = alloc_nr(commit_graft_alloc);
 144                commit_graft = xrealloc(commit_graft,
 145                                        sizeof(*commit_graft) *
 146                                        commit_graft_alloc);
 147        }
 148        if (pos < commit_graft_nr)
 149                memmove(commit_graft + pos + 1,
 150                        commit_graft + pos,
 151                        (commit_graft_nr - pos - 1) *
 152                        sizeof(*commit_graft));
 153        commit_graft[pos] = graft;
 154        return 0;
 155}
 156
 157struct commit_graft *read_graft_line(char *buf, int len)
 158{
 159        /* The format is just "Commit Parent1 Parent2 ...\n" */
 160        int i;
 161        struct commit_graft *graft = NULL;
 162
 163        if (buf[len-1] == '\n')
 164                buf[--len] = 0;
 165        if (buf[0] == '#' || buf[0] == '\0')
 166                return NULL;
 167        if ((len + 1) % 41) {
 168        bad_graft_data:
 169                error("bad graft data: %s", buf);
 170                free(graft);
 171                return NULL;
 172        }
 173        i = (len + 1) / 41 - 1;
 174        graft = xmalloc(sizeof(*graft) + 20 * i);
 175        graft->nr_parent = i;
 176        if (get_sha1_hex(buf, graft->sha1))
 177                goto bad_graft_data;
 178        for (i = 40; i < len; i += 41) {
 179                if (buf[i] != ' ')
 180                        goto bad_graft_data;
 181                if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 182                        goto bad_graft_data;
 183        }
 184        return graft;
 185}
 186
 187int read_graft_file(const char *graft_file)
 188{
 189        FILE *fp = fopen(graft_file, "r");
 190        char buf[1024];
 191        if (!fp)
 192                return -1;
 193        while (fgets(buf, sizeof(buf), fp)) {
 194                /* The format is just "Commit Parent1 Parent2 ...\n" */
 195                int len = strlen(buf);
 196                struct commit_graft *graft = read_graft_line(buf, len);
 197                if (!graft)
 198                        continue;
 199                if (register_commit_graft(graft, 1))
 200                        error("duplicate graft data: %s", buf);
 201        }
 202        fclose(fp);
 203        return 0;
 204}
 205
 206static void prepare_commit_graft(void)
 207{
 208        static int commit_graft_prepared;
 209        char *graft_file;
 210
 211        if (commit_graft_prepared)
 212                return;
 213        graft_file = get_graft_file();
 214        read_graft_file(graft_file);
 215        commit_graft_prepared = 1;
 216}
 217
 218static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 219{
 220        int pos;
 221        prepare_commit_graft();
 222        pos = commit_graft_pos(sha1);
 223        if (pos < 0)
 224                return NULL;
 225        return commit_graft[pos];
 226}
 227
 228int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 229{
 230        char *bufptr = buffer;
 231        unsigned char parent[20];
 232        struct commit_list **pptr;
 233        struct commit_graft *graft;
 234        unsigned n_refs = 0;
 235
 236        if (item->object.parsed)
 237                return 0;
 238        item->object.parsed = 1;
 239        if (memcmp(bufptr, "tree ", 5))
 240                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 241        if (get_sha1_hex(bufptr + 5, parent) < 0)
 242                return error("bad tree pointer in commit %s",
 243                             sha1_to_hex(item->object.sha1));
 244        item->tree = lookup_tree(parent);
 245        if (item->tree)
 246                n_refs++;
 247        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 248        pptr = &item->parents;
 249
 250        graft = lookup_commit_graft(item->object.sha1);
 251        while (!memcmp(bufptr, "parent ", 7)) {
 252                struct commit *new_parent;
 253
 254                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 255                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 256                bufptr += 48;
 257                if (graft)
 258                        continue;
 259                new_parent = lookup_commit(parent);
 260                if (new_parent) {
 261                        pptr = &commit_list_insert(new_parent, pptr)->next;
 262                        n_refs++;
 263                }
 264        }
 265        if (graft) {
 266                int i;
 267                struct commit *new_parent;
 268                for (i = 0; i < graft->nr_parent; i++) {
 269                        new_parent = lookup_commit(graft->parent[i]);
 270                        if (!new_parent)
 271                                continue;
 272                        pptr = &commit_list_insert(new_parent, pptr)->next;
 273                        n_refs++;
 274                }
 275        }
 276        item->date = parse_commit_date(bufptr);
 277
 278        if (track_object_refs) {
 279                unsigned i = 0;
 280                struct commit_list *p;
 281                struct object_refs *refs = alloc_object_refs(n_refs);
 282                if (item->tree)
 283                        refs->ref[i++] = &item->tree->object;
 284                for (p = item->parents; p; p = p->next)
 285                        refs->ref[i++] = &p->item->object;
 286                set_object_refs(&item->object, refs);
 287        }
 288
 289        return 0;
 290}
 291
 292int parse_commit(struct commit *item)
 293{
 294        char type[20];
 295        void *buffer;
 296        unsigned long size;
 297        int ret;
 298
 299        if (item->object.parsed)
 300                return 0;
 301        buffer = read_sha1_file(item->object.sha1, type, &size);
 302        if (!buffer)
 303                return error("Could not read %s",
 304                             sha1_to_hex(item->object.sha1));
 305        if (strcmp(type, commit_type)) {
 306                free(buffer);
 307                return error("Object %s not a commit",
 308                             sha1_to_hex(item->object.sha1));
 309        }
 310        ret = parse_commit_buffer(item, buffer, size);
 311        if (save_commit_buffer && !ret) {
 312                item->buffer = buffer;
 313                return 0;
 314        }
 315        free(buffer);
 316        return ret;
 317}
 318
 319struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 320{
 321        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 322        new_list->item = item;
 323        new_list->next = *list_p;
 324        *list_p = new_list;
 325        return new_list;
 326}
 327
 328void free_commit_list(struct commit_list *list)
 329{
 330        while (list) {
 331                struct commit_list *temp = list;
 332                list = temp->next;
 333                free(temp);
 334        }
 335}
 336
 337struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 338{
 339        struct commit_list **pp = list;
 340        struct commit_list *p;
 341        while ((p = *pp) != NULL) {
 342                if (p->item->date < item->date) {
 343                        break;
 344                }
 345                pp = &p->next;
 346        }
 347        return commit_list_insert(item, pp);
 348}
 349
 350        
 351void sort_by_date(struct commit_list **list)
 352{
 353        struct commit_list *ret = NULL;
 354        while (*list) {
 355                insert_by_date((*list)->item, &ret);
 356                *list = (*list)->next;
 357        }
 358        *list = ret;
 359}
 360
 361struct commit *pop_most_recent_commit(struct commit_list **list,
 362                                      unsigned int mark)
 363{
 364        struct commit *ret = (*list)->item;
 365        struct commit_list *parents = ret->parents;
 366        struct commit_list *old = *list;
 367
 368        *list = (*list)->next;
 369        free(old);
 370
 371        while (parents) {
 372                struct commit *commit = parents->item;
 373                parse_commit(commit);
 374                if (!(commit->object.flags & mark)) {
 375                        commit->object.flags |= mark;
 376                        insert_by_date(commit, list);
 377                }
 378                parents = parents->next;
 379        }
 380        return ret;
 381}
 382
 383void clear_commit_marks(struct commit *commit, unsigned int mark)
 384{
 385        struct commit_list *parents;
 386
 387        parents = commit->parents;
 388        commit->object.flags &= ~mark;
 389        while (parents) {
 390                struct commit *parent = parents->item;
 391                if (parent && parent->object.parsed &&
 392                    (parent->object.flags & mark))
 393                        clear_commit_marks(parent, mark);
 394                parents = parents->next;
 395        }
 396}
 397
 398/*
 399 * Generic support for pretty-printing the header
 400 */
 401static int get_one_line(const char *msg, unsigned long len)
 402{
 403        int ret = 0;
 404
 405        while (len--) {
 406                char c = *msg++;
 407                if (!c)
 408                        break;
 409                ret++;
 410                if (c == '\n')
 411                        break;
 412        }
 413        return ret;
 414}
 415
 416static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 417{
 418        char *date;
 419        int namelen;
 420        unsigned long time;
 421        int tz, ret;
 422        const char *filler = "    ";
 423
 424        if (fmt == CMIT_FMT_ONELINE)
 425                return 0;
 426        date = strchr(line, '>');
 427        if (!date)
 428                return 0;
 429        namelen = ++date - line;
 430        time = strtoul(date, &date, 10);
 431        tz = strtol(date, NULL, 10);
 432
 433        if (fmt == CMIT_FMT_EMAIL) {
 434                what = "From";
 435                filler = "";
 436        }
 437        ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 438                      (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 439                      filler, namelen, line);
 440        switch (fmt) {
 441        case CMIT_FMT_MEDIUM:
 442                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 443                break;
 444        case CMIT_FMT_EMAIL:
 445                ret += sprintf(buf + ret, "Date: %s\n",
 446                               show_rfc2822_date(time, tz));
 447                break;
 448        case CMIT_FMT_FULLER:
 449                ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 450                break;
 451        default:
 452                /* notin' */
 453                break;
 454        }
 455        return ret;
 456}
 457
 458static int is_empty_line(const char *line, int *len_p)
 459{
 460        int len = *len_p;
 461        while (len && isspace(line[len-1]))
 462                len--;
 463        *len_p = len;
 464        return !len;
 465}
 466
 467static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 468{
 469        struct commit_list *parent = commit->parents;
 470        int offset;
 471
 472        if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
 473            !parent || !parent->next)
 474                return 0;
 475
 476        offset = sprintf(buf, "Merge:");
 477
 478        while (parent) {
 479                struct commit *p = parent->item;
 480                const char *hex = abbrev
 481                        ? find_unique_abbrev(p->object.sha1, abbrev)
 482                        : sha1_to_hex(p->object.sha1);
 483                char *dots = (abbrev && strlen(hex) != 40) ? "..." : "";
 484                parent = parent->next;
 485
 486                offset += sprintf(buf + offset, " %s%s", hex, dots);
 487        }
 488        buf[offset++] = '\n';
 489        return offset;
 490}
 491
 492unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit, unsigned long len, char *buf, unsigned long space, int abbrev, const char *subject)
 493{
 494        int hdr = 1, body = 0;
 495        unsigned long offset = 0;
 496        int indent = 4;
 497        int parents_shown = 0;
 498        const char *msg = commit->buffer;
 499
 500        if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
 501                indent = 0;
 502
 503        for (;;) {
 504                const char *line = msg;
 505                int linelen = get_one_line(msg, len);
 506
 507                if (!linelen)
 508                        break;
 509
 510                /*
 511                 * We want some slop for indentation and a possible
 512                 * final "...". Thus the "+ 20".
 513                 */
 514                if (offset + linelen + 20 > space) {
 515                        memcpy(buf + offset, "    ...\n", 8);
 516                        offset += 8;
 517                        break;
 518                }
 519
 520                msg += linelen;
 521                len -= linelen;
 522                if (hdr) {
 523                        if (linelen == 1) {
 524                                hdr = 0;
 525                                if ((fmt != CMIT_FMT_ONELINE) && !subject)
 526                                        buf[offset++] = '\n';
 527                                continue;
 528                        }
 529                        if (fmt == CMIT_FMT_RAW) {
 530                                memcpy(buf + offset, line, linelen);
 531                                offset += linelen;
 532                                continue;
 533                        }
 534                        if (!memcmp(line, "parent ", 7)) {
 535                                if (linelen != 48)
 536                                        die("bad parent line in commit");
 537                                continue;
 538                        }
 539
 540                        if (!parents_shown) {
 541                                offset += add_merge_info(fmt, buf + offset,
 542                                                         commit, abbrev);
 543                                parents_shown = 1;
 544                                continue;
 545                        }
 546                        /*
 547                         * MEDIUM == DEFAULT shows only author with dates.
 548                         * FULL shows both authors but not dates.
 549                         * FULLER shows both authors and dates.
 550                         */
 551                        if (!memcmp(line, "author ", 7))
 552                                offset += add_user_info("Author", fmt,
 553                                                        buf + offset,
 554                                                        line + 7);
 555                        if (!memcmp(line, "committer ", 10) &&
 556                            (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 557                                offset += add_user_info("Commit", fmt,
 558                                                        buf + offset,
 559                                                        line + 10);
 560                        continue;
 561                }
 562
 563                if (is_empty_line(line, &linelen)) {
 564                        if (!body)
 565                                continue;
 566                        if (subject)
 567                                continue;
 568                        if (fmt == CMIT_FMT_SHORT)
 569                                break;
 570                } else {
 571                        body = 1;
 572                }
 573
 574                if (subject) {
 575                        int slen = strlen(subject);
 576                        memcpy(buf + offset, subject, slen);
 577                        offset += slen;
 578                }
 579                memset(buf + offset, ' ', indent);
 580                memcpy(buf + offset + indent, line, linelen);
 581                offset += linelen + indent;
 582                buf[offset++] = '\n';
 583                if (fmt == CMIT_FMT_ONELINE)
 584                        break;
 585                subject = NULL;
 586        }
 587        while (offset && isspace(buf[offset-1]))
 588                offset--;
 589        /* Make sure there is an EOLN for the non-oneline case */
 590        if (fmt != CMIT_FMT_ONELINE)
 591                buf[offset++] = '\n';
 592        buf[offset] = '\0';
 593        return offset;
 594}
 595
 596struct commit *pop_commit(struct commit_list **stack)
 597{
 598        struct commit_list *top = *stack;
 599        struct commit *item = top ? top->item : NULL;
 600
 601        if (top) {
 602                *stack = top->next;
 603                free(top);
 604        }
 605        return item;
 606}
 607
 608int count_parents(struct commit * commit)
 609{
 610        int count = 0;
 611        struct commit_list * parents = commit->parents;
 612        for (count=0;parents; parents=parents->next,count++)
 613          ;
 614        return count;
 615}
 616
 617void topo_sort_default_setter(struct commit *c, void *data)
 618{
 619        c->object.util = data;
 620}
 621
 622void *topo_sort_default_getter(struct commit *c)
 623{
 624        return c->object.util;
 625}
 626
 627/*
 628 * Performs an in-place topological sort on the list supplied.
 629 */
 630void sort_in_topological_order(struct commit_list ** list, int lifo)
 631{
 632        sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 633                                     topo_sort_default_getter);
 634}
 635
 636void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 637                                  topo_sort_set_fn_t setter,
 638                                  topo_sort_get_fn_t getter)
 639{
 640        struct commit_list * next = *list;
 641        struct commit_list * work = NULL, **insert;
 642        struct commit_list ** pptr = list;
 643        struct sort_node * nodes;
 644        struct sort_node * next_nodes;
 645        int count = 0;
 646
 647        /* determine the size of the list */
 648        while (next) {
 649                next = next->next;
 650                count++;
 651        }
 652        
 653        if (!count)
 654                return;
 655        /* allocate an array to help sort the list */
 656        nodes = xcalloc(count, sizeof(*nodes));
 657        /* link the list to the array */
 658        next_nodes = nodes;
 659        next=*list;
 660        while (next) {
 661                next_nodes->list_item = next;
 662                setter(next->item, next_nodes);
 663                next_nodes++;
 664                next = next->next;
 665        }
 666        /* update the indegree */
 667        next=*list;
 668        while (next) {
 669                struct commit_list * parents = next->item->parents;
 670                while (parents) {
 671                        struct commit * parent=parents->item;
 672                        struct sort_node * pn = (struct sort_node *) getter(parent);
 673
 674                        if (pn)
 675                                pn->indegree++;
 676                        parents=parents->next;
 677                }
 678                next=next->next;
 679        }
 680        /* 
 681         * find the tips
 682         *
 683         * tips are nodes not reachable from any other node in the list 
 684         * 
 685         * the tips serve as a starting set for the work queue.
 686         */
 687        next=*list;
 688        insert = &work;
 689        while (next) {
 690                struct sort_node * node = (struct sort_node *) getter(next->item);
 691
 692                if (node->indegree == 0) {
 693                        insert = &commit_list_insert(next->item, insert)->next;
 694                }
 695                next=next->next;
 696        }
 697
 698        /* process the list in topological order */
 699        if (!lifo)
 700                sort_by_date(&work);
 701        while (work) {
 702                struct commit * work_item = pop_commit(&work);
 703                struct sort_node * work_node = (struct sort_node *) getter(work_item);
 704                struct commit_list * parents = work_item->parents;
 705
 706                while (parents) {
 707                        struct commit * parent=parents->item;
 708                        struct sort_node * pn = (struct sort_node *) getter(parent);
 709
 710                        if (pn) {
 711                                /*
 712                                 * parents are only enqueued for emission 
 713                                 * when all their children have been emitted thereby
 714                                 * guaranteeing topological order.
 715                                 */
 716                                pn->indegree--;
 717                                if (!pn->indegree) {
 718                                        if (!lifo)
 719                                                insert_by_date(parent, &work);
 720                                        else
 721                                                commit_list_insert(parent, &work);
 722                                }
 723                        }
 724                        parents=parents->next;
 725                }
 726                /*
 727                 * work_item is a commit all of whose children
 728                 * have already been emitted. we can emit it now.
 729                 */
 730                *pptr = work_node->list_item;
 731                pptr = &(*pptr)->next;
 732                *pptr = NULL;
 733                setter(work_item, NULL);
 734        }
 735        free(nodes);
 736}