Andrew's git / gitweb.git / commit.c
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commit.con commit http-push.c: include with angle bracket, not dq. (bee8e79)
   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, "=oneline"))
  38                return CMIT_FMT_ONELINE;
  39        die("invalid --pretty format");
  40}
  41
  42static struct commit *check_commit(struct object *obj,
  43                                   const unsigned char *sha1,
  44                                   int quiet)
  45{
  46        if (obj->type != commit_type) {
  47                if (!quiet)
  48                        error("Object %s is a %s, not a commit",
  49                              sha1_to_hex(sha1), obj->type);
  50                return NULL;
  51        }
  52        return (struct commit *) obj;
  53}
  54
  55struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  56                                              int quiet)
  57{
  58        struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  59
  60        if (!obj)
  61                return NULL;
  62        return check_commit(obj, sha1, quiet);
  63}
  64
  65struct commit *lookup_commit_reference(const unsigned char *sha1)
  66{
  67        return lookup_commit_reference_gently(sha1, 0);
  68}
  69
  70struct commit *lookup_commit(const unsigned char *sha1)
  71{
  72        struct object *obj = lookup_object(sha1);
  73        if (!obj) {
  74                struct commit *ret = xmalloc(sizeof(struct commit));
  75                memset(ret, 0, sizeof(struct commit));
  76                created_object(sha1, &ret->object);
  77                ret->object.type = commit_type;
  78                return ret;
  79        }
  80        if (!obj->type)
  81                obj->type = commit_type;
  82        return check_commit(obj, sha1, 0);
  83}
  84
  85static unsigned long parse_commit_date(const char *buf)
  86{
  87        unsigned long date;
  88
  89        if (memcmp(buf, "author", 6))
  90                return 0;
  91        while (*buf++ != '\n')
  92                /* nada */;
  93        if (memcmp(buf, "committer", 9))
  94                return 0;
  95        while (*buf++ != '>')
  96                /* nada */;
  97        date = strtoul(buf, NULL, 10);
  98        if (date == ULONG_MAX)
  99                date = 0;
 100        return date;
 101}
 102
 103static struct commit_graft {
 104        unsigned char sha1[20];
 105        int nr_parent;
 106        unsigned char parent[0][20]; /* more */
 107} **commit_graft;
 108static int commit_graft_alloc, commit_graft_nr;
 109
 110static int commit_graft_pos(const unsigned char *sha1)
 111{
 112        int lo, hi;
 113        lo = 0;
 114        hi = commit_graft_nr;
 115        while (lo < hi) {
 116                int mi = (lo + hi) / 2;
 117                struct commit_graft *graft = commit_graft[mi];
 118                int cmp = memcmp(sha1, graft->sha1, 20);
 119                if (!cmp)
 120                        return mi;
 121                if (cmp < 0)
 122                        hi = mi;
 123                else
 124                        lo = mi + 1;
 125        }
 126        return -lo - 1;
 127}
 128
 129static void prepare_commit_graft(void)
 130{
 131        char *graft_file = get_graft_file();
 132        FILE *fp = fopen(graft_file, "r");
 133        char buf[1024];
 134        if (!fp) {
 135                commit_graft = (struct commit_graft **) "hack";
 136                return;
 137        }
 138        while (fgets(buf, sizeof(buf), fp)) {
 139                /* The format is just "Commit Parent1 Parent2 ...\n" */
 140                int len = strlen(buf);
 141                int i;
 142                struct commit_graft *graft = NULL;
 143
 144                if (buf[len-1] == '\n')
 145                        buf[--len] = 0;
 146                if (buf[0] == '#')
 147                        continue;
 148                if ((len + 1) % 41) {
 149                bad_graft_data:
 150                        error("bad graft data: %s", buf);
 151                        free(graft);
 152                        continue;
 153                }
 154                i = (len + 1) / 41 - 1;
 155                graft = xmalloc(sizeof(*graft) + 20 * i);
 156                graft->nr_parent = i;
 157                if (get_sha1_hex(buf, graft->sha1))
 158                        goto bad_graft_data;
 159                for (i = 40; i < len; i += 41) {
 160                        if (buf[i] != ' ')
 161                                goto bad_graft_data;
 162                        if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 163                                goto bad_graft_data;
 164                }
 165                i = commit_graft_pos(graft->sha1);
 166                if (0 <= i) {
 167                        error("duplicate graft data: %s", buf);
 168                        free(graft);
 169                        continue;
 170                }
 171                i = -i - 1;
 172                if (commit_graft_alloc <= ++commit_graft_nr) {
 173                        commit_graft_alloc = alloc_nr(commit_graft_alloc);
 174                        commit_graft = xrealloc(commit_graft,
 175                                                sizeof(*commit_graft) *
 176                                                commit_graft_alloc);
 177                }
 178                if (i < commit_graft_nr)
 179                        memmove(commit_graft + i + 1,
 180                                commit_graft + i,
 181                                (commit_graft_nr - i - 1) *
 182                                sizeof(*commit_graft));
 183                commit_graft[i] = graft;
 184        }
 185        fclose(fp);
 186}
 187
 188static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 189{
 190        int pos;
 191        if (!commit_graft)
 192                prepare_commit_graft();
 193        pos = commit_graft_pos(sha1);
 194        if (pos < 0)
 195                return NULL;
 196        return commit_graft[pos];
 197}
 198
 199int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 200{
 201        char *bufptr = buffer;
 202        unsigned char parent[20];
 203        struct commit_list **pptr;
 204        struct commit_graft *graft;
 205
 206        if (item->object.parsed)
 207                return 0;
 208        item->object.parsed = 1;
 209        if (memcmp(bufptr, "tree ", 5))
 210                return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 211        if (get_sha1_hex(bufptr + 5, parent) < 0)
 212                return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 213        item->tree = lookup_tree(parent);
 214        if (item->tree)
 215                add_ref(&item->object, &item->tree->object);
 216        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 217        pptr = &item->parents;
 218
 219        graft = lookup_commit_graft(item->object.sha1);
 220        while (!memcmp(bufptr, "parent ", 7)) {
 221                struct commit *new_parent;
 222
 223                if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 224                        return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 225                bufptr += 48;
 226                if (graft)
 227                        continue;
 228                new_parent = lookup_commit(parent);
 229                if (new_parent) {
 230                        pptr = &commit_list_insert(new_parent, pptr)->next;
 231                        add_ref(&item->object, &new_parent->object);
 232                }
 233        }
 234        if (graft) {
 235                int i;
 236                struct commit *new_parent;
 237                for (i = 0; i < graft->nr_parent; i++) {
 238                        new_parent = lookup_commit(graft->parent[i]);
 239                        if (!new_parent)
 240                                continue;
 241                        pptr = &commit_list_insert(new_parent, pptr)->next;
 242                        add_ref(&item->object, &new_parent->object);
 243                }
 244        }
 245        item->date = parse_commit_date(bufptr);
 246        return 0;
 247}
 248
 249int parse_commit(struct commit *item)
 250{
 251        char type[20];
 252        void *buffer;
 253        unsigned long size;
 254        int ret;
 255
 256        if (item->object.parsed)
 257                return 0;
 258        buffer = read_sha1_file(item->object.sha1, type, &size);
 259        if (!buffer)
 260                return error("Could not read %s",
 261                             sha1_to_hex(item->object.sha1));
 262        if (strcmp(type, commit_type)) {
 263                free(buffer);
 264                return error("Object %s not a commit",
 265                             sha1_to_hex(item->object.sha1));
 266        }
 267        ret = parse_commit_buffer(item, buffer, size);
 268        if (save_commit_buffer && !ret) {
 269                item->buffer = buffer;
 270                return 0;
 271        }
 272        free(buffer);
 273        return ret;
 274}
 275
 276struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 277{
 278        struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 279        new_list->item = item;
 280        new_list->next = *list_p;
 281        *list_p = new_list;
 282        return new_list;
 283}
 284
 285void free_commit_list(struct commit_list *list)
 286{
 287        while (list) {
 288                struct commit_list *temp = list;
 289                list = temp->next;
 290                free(temp);
 291        }
 292}
 293
 294struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 295{
 296        struct commit_list **pp = list;
 297        struct commit_list *p;
 298        while ((p = *pp) != NULL) {
 299                if (p->item->date < item->date) {
 300                        break;
 301                }
 302                pp = &p->next;
 303        }
 304        return commit_list_insert(item, pp);
 305}
 306
 307        
 308void sort_by_date(struct commit_list **list)
 309{
 310        struct commit_list *ret = NULL;
 311        while (*list) {
 312                insert_by_date((*list)->item, &ret);
 313                *list = (*list)->next;
 314        }
 315        *list = ret;
 316}
 317
 318struct commit *pop_most_recent_commit(struct commit_list **list,
 319                                      unsigned int mark)
 320{
 321        struct commit *ret = (*list)->item;
 322        struct commit_list *parents = ret->parents;
 323        struct commit_list *old = *list;
 324
 325        *list = (*list)->next;
 326        free(old);
 327
 328        while (parents) {
 329                struct commit *commit = parents->item;
 330                parse_commit(commit);
 331                if (!(commit->object.flags & mark)) {
 332                        commit->object.flags |= mark;
 333                        insert_by_date(commit, list);
 334                }
 335                parents = parents->next;
 336        }
 337        return ret;
 338}
 339
 340/*
 341 * Generic support for pretty-printing the header
 342 */
 343static int get_one_line(const char *msg, unsigned long len)
 344{
 345        int ret = 0;
 346
 347        while (len--) {
 348                char c = *msg++;
 349                ret++;
 350                if (c == '\n')
 351                        break;
 352                if (!c)
 353                        return 0;
 354        }
 355        return ret;
 356}
 357
 358static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 359{
 360        char *date;
 361        int namelen;
 362        unsigned long time;
 363        int tz, ret;
 364
 365        if (fmt == CMIT_FMT_ONELINE)
 366                return 0;
 367        date = strchr(line, '>');
 368        if (!date)
 369                return 0;
 370        namelen = ++date - line;
 371        time = strtoul(date, &date, 10);
 372        tz = strtol(date, NULL, 10);
 373
 374        ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
 375        if (fmt == CMIT_FMT_MEDIUM)
 376                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 377        return ret;
 378}
 379
 380static int is_empty_line(const char *line, int len)
 381{
 382        while (len && isspace(line[len-1]))
 383                len--;
 384        return !len;
 385}
 386
 387static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 388{
 389        int offset = 0;
 390
 391        if (fmt == CMIT_FMT_ONELINE)
 392                return offset;
 393        switch (parents) {
 394        case 1:
 395                break;
 396        case 2:
 397                /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 398                offset = sprintf(buf, "Merge: %.40s\n", line-41);
 399                /* Fallthrough */
 400        default:
 401                /* Replace the previous '\n' with a space */
 402                buf[offset-1] = ' ';
 403                offset += sprintf(buf + offset, "%.40s\n", line+7);
 404        }
 405        return offset;
 406}
 407
 408unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 409{
 410        int hdr = 1, body = 0;
 411        unsigned long offset = 0;
 412        int parents = 0;
 413        int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 414
 415        for (;;) {
 416                const char *line = msg;
 417                int linelen = get_one_line(msg, len);
 418
 419                if (!linelen)
 420                        break;
 421
 422                /*
 423                 * We want some slop for indentation and a possible
 424                 * final "...". Thus the "+ 20".
 425                 */
 426                if (offset + linelen + 20 > space) {
 427                        memcpy(buf + offset, "    ...\n", 8);
 428                        offset += 8;
 429                        break;
 430                }
 431
 432                msg += linelen;
 433                len -= linelen;
 434                if (hdr) {
 435                        if (linelen == 1) {
 436                                hdr = 0;
 437                                if (fmt != CMIT_FMT_ONELINE)
 438                                        buf[offset++] = '\n';
 439                                continue;
 440                        }
 441                        if (fmt == CMIT_FMT_RAW) {
 442                                memcpy(buf + offset, line, linelen);
 443                                offset += linelen;
 444                                continue;
 445                        }
 446                        if (!memcmp(line, "parent ", 7)) {
 447                                if (linelen != 48)
 448                                        die("bad parent line in commit");
 449                                offset += add_parent_info(fmt, buf + offset, line, ++parents);
 450                        }
 451                        if (!memcmp(line, "author ", 7))
 452                                offset += add_user_info("Author", fmt, buf + offset, line + 7);
 453                        if (fmt == CMIT_FMT_FULL) {
 454                                if (!memcmp(line, "committer ", 10))
 455                                        offset += add_user_info("Commit", fmt, buf + offset, line + 10);
 456                        }
 457                        continue;
 458                }
 459
 460                if (is_empty_line(line, linelen)) {
 461                        if (!body)
 462                                continue;
 463                        if (fmt == CMIT_FMT_SHORT)
 464                                break;
 465                } else {
 466                        body = 1;
 467                }
 468
 469                memset(buf + offset, ' ', indent);
 470                memcpy(buf + offset + indent, line, linelen);
 471                offset += linelen + indent;
 472                if (fmt == CMIT_FMT_ONELINE)
 473                        break;
 474        }
 475        if (fmt == CMIT_FMT_ONELINE) {
 476                /* We do not want the terminating newline */
 477                if (buf[offset - 1] == '\n')
 478                        offset--;
 479        }
 480        else {
 481                /* Make sure there is an EOLN */
 482                if (buf[offset - 1] != '\n')
 483                        buf[offset++] = '\n';
 484        }
 485        buf[offset] = '\0';
 486        return offset;
 487}
 488
 489struct commit *pop_commit(struct commit_list **stack)
 490{
 491        struct commit_list *top = *stack;
 492        struct commit *item = top ? top->item : NULL;
 493
 494        if (top) {
 495                *stack = top->next;
 496                free(top);
 497        }
 498        return item;
 499}
 500
 501int count_parents(struct commit * commit)
 502{
 503        int count = 0;
 504        struct commit_list * parents = commit->parents;
 505        for (count=0;parents; parents=parents->next,count++)
 506          ;
 507        return count;
 508}
 509
 510/*
 511 * Performs an in-place topological sort on the list supplied.
 512 */
 513void sort_in_topological_order(struct commit_list ** list)
 514{
 515        struct commit_list * next = *list;
 516        struct commit_list * work = NULL;
 517        struct commit_list ** pptr = list;
 518        struct sort_node * nodes;
 519        struct sort_node * next_nodes;
 520        int count = 0;
 521
 522        /* determine the size of the list */
 523        while (next) {
 524                next = next->next;
 525                count++;
 526        }
 527        /* allocate an array to help sort the list */
 528        nodes = xcalloc(count, sizeof(*nodes));
 529        /* link the list to the array */
 530        next_nodes = nodes;
 531        next=*list;
 532        while (next) {
 533                next_nodes->list_item = next;
 534                next->item->object.util = next_nodes;
 535                next_nodes++;
 536                next = next->next;
 537        }
 538        /* update the indegree */
 539        next=*list;
 540        while (next) {
 541                struct commit_list * parents = next->item->parents;
 542                while (parents) {
 543                        struct commit * parent=parents->item;
 544                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 545                        
 546                        if (pn)
 547                                pn->indegree++;
 548                        parents=parents->next;
 549                }
 550                next=next->next;
 551        }
 552        /* 
 553         * find the tips
 554         *
 555         * tips are nodes not reachable from any other node in the list 
 556         * 
 557         * the tips serve as a starting set for the work queue.
 558         */
 559        next=*list;
 560        while (next) {
 561                struct sort_node * node = (struct sort_node *)next->item->object.util;
 562
 563                if (node->indegree == 0) {
 564                        commit_list_insert(next->item, &work);
 565                }
 566                next=next->next;
 567        }
 568        /* process the list in topological order */
 569        while (work) {
 570                struct commit * work_item = pop_commit(&work);
 571                struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 572                struct commit_list * parents = work_item->parents;
 573
 574                while (parents) {
 575                        struct commit * parent=parents->item;
 576                        struct sort_node * pn = (struct sort_node *)parent->object.util;
 577                        
 578                        if (pn) {
 579                                /* 
 580                                 * parents are only enqueued for emission 
 581                                 * when all their children have been emitted thereby
 582                                 * guaranteeing topological order.
 583                                 */
 584                                pn->indegree--;
 585                                if (!pn->indegree) 
 586                                        commit_list_insert(parent, &work);
 587                        }
 588                        parents=parents->next;
 589                }
 590                /*
 591                 * work_item is a commit all of whose children
 592                 * have already been emitted. we can emit it now.
 593                 */
 594                *pptr = work_node->list_item;
 595                pptr = &(*pptr)->next;
 596                *pptr = NULL;
 597                work_item->object.util = NULL;
 598        }
 599        free(nodes);
 600}