Andrew's git / gitweb.git / commit.c
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commit.con commit GIT 0.99.9h (f7a2eb7)
   1#include "tag.h"
   2#include "commit.h"
   3#include "cache.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
 208        if (item->object.parsed)
 209                return 0;
 210        item->object.parsed = 1;
 211        if (memcmp(bufptr, "tree ", 5))
 212                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 213        if (get_sha1_hex(bufptr + 5, parent) < 0)
 214                return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 215        item->tree = lookup_tree(parent);
 216        if (item->tree)
 217                add_ref(&item->object, &item->tree->object);
 218        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 219        pptr = &item->parents;
 220
 221        graft = lookup_commit_graft(item->object.sha1);
 222        while (!memcmp(bufptr, "parent ", 7)) {
 223                struct commit *new_parent;
 224
 225                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 226                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 227                bufptr += 48;
 228                if (graft)
 229                        continue;
 230                new_parent = lookup_commit(parent);
 231                if (new_parent) {
 232                        pptr = &commit_list_insert(new_parent, pptr)->next;
 233                        add_ref(&item->object, &new_parent->object);
 234                }
 235        }
 236        if (graft) {
 237                int i;
 238                struct commit *new_parent;
 239                for (i = 0; i < graft->nr_parent; i++) {
 240                        new_parent = lookup_commit(graft->parent[i]);
 241                        if (!new_parent)
 242                                continue;
 243                        pptr = &commit_list_insert(new_parent, pptr)->next;
 244                        add_ref(&item->object, &new_parent->object);
 245                }
 246        }
 247        item->date = parse_commit_date(bufptr);
 248        return 0;
 249}
 250
 251int parse_commit(struct commit *item)
 252{
 253        char type[20];
 254        void *buffer;
 255        unsigned long size;
 256        int ret;
 257
 258        if (item->object.parsed)
 259                return 0;
 260        buffer = read_sha1_file(item->object.sha1, type, &size);
 261        if (!buffer)
 262                return error("Could not read %s",
 263                             sha1_to_hex(item->object.sha1));
 264        if (strcmp(type, commit_type)) {
 265                free(buffer);
 266                return error("Object %s not a commit",
 267                             sha1_to_hex(item->object.sha1));
 268        }
 269        ret = parse_commit_buffer(item, buffer, size);
 270        if (save_commit_buffer && !ret) {
 271                item->buffer = buffer;
 272                return 0;
 273        }
 274        free(buffer);
 275        return ret;
 276}
 277
 278struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 279{
 280        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 281        new_list->item = item;
 282        new_list->next = *list_p;
 283        *list_p = new_list;
 284        return new_list;
 285}
 286
 287void free_commit_list(struct commit_list *list)
 288{
 289        while (list) {
 290                struct commit_list *temp = list;
 291                list = temp->next;
 292                free(temp);
 293        }
 294}
 295
 296struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 297{
 298        struct commit_list **pp = list;
 299        struct commit_list *p;
 300        while ((p = *pp) != NULL) {
 301                if (p->item->date < item->date) {
 302                        break;
 303                }
 304                pp = &p->next;
 305        }
 306        return commit_list_insert(item, pp);
 307}
 308
 309        
 310void sort_by_date(struct commit_list **list)
 311{
 312        struct commit_list *ret = NULL;
 313        while (*list) {
 314                insert_by_date((*list)->item, &ret);
 315                *list = (*list)->next;
 316        }
 317        *list = ret;
 318}
 319
 320struct commit *pop_most_recent_commit(struct commit_list **list,
 321                                      unsigned int mark)
 322{
 323        struct commit *ret = (*list)->item;
 324        struct commit_list *parents = ret->parents;
 325        struct commit_list *old = *list;
 326
 327        *list = (*list)->next;
 328        free(old);
 329
 330        while (parents) {
 331                struct commit *commit = parents->item;
 332                parse_commit(commit);
 333                if (!(commit->object.flags & mark)) {
 334                        commit->object.flags |= mark;
 335                        insert_by_date(commit, list);
 336                }
 337                parents = parents->next;
 338        }
 339        return ret;
 340}
 341
 342/*
 343 * Generic support for pretty-printing the header
 344 */
 345static int get_one_line(const char *msg, unsigned long len)
 346{
 347        int ret = 0;
 348
 349        while (len--) {
 350                char c = *msg++;
 351                ret++;
 352                if (c == '\n')
 353                        break;
 354                if (!c)
 355                        return 0;
 356        }
 357        return ret;
 358}
 359
 360static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 361{
 362        char *date;
 363        int namelen;
 364        unsigned long time;
 365        int tz, ret;
 366        const char *filler = "    ";
 367
 368        if (fmt == CMIT_FMT_ONELINE)
 369                return 0;
 370        date = strchr(line, '>');
 371        if (!date)
 372                return 0;
 373        namelen = ++date - line;
 374        time = strtoul(date, &date, 10);
 375        tz = strtol(date, NULL, 10);
 376
 377        ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 378                      (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 379                      filler, namelen, line);
 380        switch (fmt) {
 381        case CMIT_FMT_MEDIUM:
 382                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 383                break;
 384        case CMIT_FMT_FULLER:
 385                ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 386                break;
 387        default:
 388                /* notin' */
 389                break;
 390        }
 391        return ret;
 392}
 393
 394static int is_empty_line(const char *line, int len)
 395{
 396        while (len && isspace(line[len-1]))
 397                len--;
 398        return !len;
 399}
 400
 401static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 402{
 403        int offset = 0;
 404
 405        if (fmt == CMIT_FMT_ONELINE)
 406                return offset;
 407        switch (parents) {
 408        case 1:
 409                break;
 410        case 2:
 411                /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 412                offset = sprintf(buf, "Merge: %.40s\n", line-41);
 413                /* Fallthrough */
 414        default:
 415                /* Replace the previous '\n' with a space */
 416                buf[offset-1] = ' ';
 417                offset += sprintf(buf + offset, "%.40s\n", line+7);
 418        }
 419        return offset;
 420}
 421
 422unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 423{
 424        int hdr = 1, body = 0;
 425        unsigned long offset = 0;
 426        int parents = 0;
 427        int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 428
 429        for (;;) {
 430                const char *line = msg;
 431                int linelen = get_one_line(msg, len);
 432
 433                if (!linelen)
 434                        break;
 435
 436                /*
 437                 * We want some slop for indentation and a possible
 438                 * final "...". Thus the "+ 20".
 439                 */
 440                if (offset + linelen + 20 > space) {
 441                        memcpy(buf + offset, "    ...\n", 8);
 442                        offset += 8;
 443                        break;
 444                }
 445
 446                msg += linelen;
 447                len -= linelen;
 448                if (hdr) {
 449                        if (linelen == 1) {
 450                                hdr = 0;
 451                                if (fmt != CMIT_FMT_ONELINE)
 452                                        buf[offset++] = '\n';
 453                                continue;
 454                        }
 455                        if (fmt == CMIT_FMT_RAW) {
 456                                memcpy(buf + offset, line, linelen);
 457                                offset += linelen;
 458                                continue;
 459                        }
 460                        if (!memcmp(line, "parent ", 7)) {
 461                                if (linelen != 48)
 462                                        die("bad parent line in commit");
 463                                offset += add_parent_info(fmt, buf + offset, line, ++parents);
 464                        }
 465
 466                        /*
 467                         * MEDIUM == DEFAULT shows only author with dates.
 468                         * FULL shows both authors but not dates.
 469                         * FULLER shows both authors and dates.
 470                         */
 471                        if (!memcmp(line, "author ", 7))
 472                                offset += add_user_info("Author", fmt,
 473                                                        buf + offset,
 474                                                        line + 7);
 475                        if (!memcmp(line, "committer ", 10) &&
 476                            (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 477                                offset += add_user_info("Commit", fmt,
 478                                                        buf + offset,
 479                                                        line + 10);
 480                        continue;
 481                }
 482
 483                if (is_empty_line(line, linelen)) {
 484                        if (!body)
 485                                continue;
 486                        if (fmt == CMIT_FMT_SHORT)
 487                                break;
 488                } else {
 489                        body = 1;
 490                }
 491
 492                memset(buf + offset, ' ', indent);
 493                memcpy(buf + offset + indent, line, linelen);
 494                offset += linelen + indent;
 495                if (fmt == CMIT_FMT_ONELINE)
 496                        break;
 497        }
 498        if (fmt == CMIT_FMT_ONELINE) {
 499                /* We do not want the terminating newline */
 500                if (buf[offset - 1] == '\n')
 501                        offset--;
 502        }
 503        else {
 504                /* Make sure there is an EOLN */
 505                if (buf[offset - 1] != '\n')
 506                        buf[offset++] = '\n';
 507        }
 508        buf[offset] = '\0';
 509        return offset;
 510}
 511
 512struct commit *pop_commit(struct commit_list **stack)
 513{
 514        struct commit_list *top = *stack;
 515        struct commit *item = top ? top->item : NULL;
 516
 517        if (top) {
 518                *stack = top->next;
 519                free(top);
 520        }
 521        return item;
 522}
 523
 524int count_parents(struct commit * commit)
 525{
 526        int count = 0;
 527        struct commit_list * parents = commit->parents;
 528        for (count=0;parents; parents=parents->next,count++)
 529          ;
 530        return count;
 531}
 532
 533/*
 534 * Performs an in-place topological sort on the list supplied.
 535 */
 536void sort_in_topological_order(struct commit_list ** list)
 537{
 538        struct commit_list * next = *list;
 539        struct commit_list * work = NULL;
 540        struct commit_list ** pptr = list;
 541        struct sort_node * nodes;
 542        struct sort_node * next_nodes;
 543        int count = 0;
 544
 545        /* determine the size of the list */
 546        while (next) {
 547                next = next->next;
 548                count++;
 549        }
 550        /* allocate an array to help sort the list */
 551        nodes = xcalloc(count, sizeof(*nodes));
 552        /* link the list to the array */
 553        next_nodes = nodes;
 554        next=*list;
 555        while (next) {
 556                next_nodes->list_item = next;
 557                next->item->object.util = next_nodes;
 558                next_nodes++;
 559                next = next->next;
 560        }
 561        /* update the indegree */
 562        next=*list;
 563        while (next) {
 564                struct commit_list * parents = next->item->parents;
 565                while (parents) {
 566                        struct commit * parent=parents->item;
 567                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 568                        
 569                        if (pn)
 570                                pn->indegree++;
 571                        parents=parents->next;
 572                }
 573                next=next->next;
 574        }
 575        /* 
 576         * find the tips
 577         *
 578         * tips are nodes not reachable from any other node in the list 
 579         * 
 580         * the tips serve as a starting set for the work queue.
 581         */
 582        next=*list;
 583        while (next) {
 584                struct sort_node * node = (struct sort_node *)next->item->object.util;
 585
 586                if (node->indegree == 0) {
 587                        commit_list_insert(next->item, &work);
 588                }
 589                next=next->next;
 590        }
 591        /* process the list in topological order */
 592        while (work) {
 593                struct commit * work_item = pop_commit(&work);
 594                struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 595                struct commit_list * parents = work_item->parents;
 596
 597                while (parents) {
 598                        struct commit * parent=parents->item;
 599                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 600                        
 601                        if (pn) {
 602                                /* 
 603                                 * parents are only enqueued for emission 
 604                                 * when all their children have been emitted thereby
 605                                 * guaranteeing topological order.
 606                                 */
 607                                pn->indegree--;
 608                                if (!pn->indegree) 
 609                                        commit_list_insert(parent, &work);
 610                        }
 611                        parents=parents->next;
 612                }
 613                /*
 614                 * work_item is a commit all of whose children
 615                 * have already been emitted. we can emit it now.
 616                 */
 617                *pptr = work_node->list_item;
 618                pptr = &(*pptr)->next;
 619                *pptr = NULL;
 620                work_item->object.util = NULL;
 621        }
 622        free(nodes);
 623}