commit.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4
   5 int save_commit_buffer = 1;
   6
   7 struct 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
  23 const char *commit_type = "commit";
  24
  25 enum 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
  44 static 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
  57 struct 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
  67 struct commit *lookup_commit_reference(const unsigned char *sha1)
  68 {
  69         return lookup_commit_reference_gently(sha1, 0);
  70 }
  71
  72 struct commit *lookup_commit(const unsigned char *sha1)
  73 {
  74         struct object *obj = lookup_object(sha1);
  75         if (!obj) {
  76                 struct commit *ret = xcalloc(1, sizeof(struct commit));
  77                 created_object(sha1, &ret->object);
  78                 ret->object.type = commit_type;
  79                 return ret;
  80         }
  81         if (!obj->type)
  82                 obj->type = commit_type;
  83         return check_commit(obj, sha1, 0);
  84 }
  85
  86 static unsigned long parse_commit_date(const char *buf)
  87 {
  88         unsigned long date;
  89
  90         if (memcmp(buf, "author", 6))
  91                 return 0;
  92         while (*buf++ != '\n')
  93                 /* nada */;
  94         if (memcmp(buf, "committer", 9))
  95                 return 0;
  96         while (*buf++ != '>')
  97                 /* nada */;
  98         date = strtoul(buf, NULL, 10);
  99         if (date == ULONG_MAX)
 100                 date = 0;
 101         return date;
 102 }
 103
 104 static struct commit_graft **commit_graft;
 105 static int commit_graft_alloc, commit_graft_nr;
 106
 107 static int commit_graft_pos(const unsigned char *sha1)
 108 {
 109         int lo, hi;
 110         lo = 0;
 111         hi = commit_graft_nr;
 112         while (lo < hi) {
 113                 int mi = (lo + hi) / 2;
 114                 struct commit_graft *graft = commit_graft[mi];
 115                 int cmp = memcmp(sha1, graft->sha1, 20);
 116                 if (!cmp)
 117                         return mi;
 118                 if (cmp < 0)
 119                         hi = mi;
 120                 else
 121                         lo = mi + 1;
 122         }
 123         return -lo - 1;
 124 }
 125
 126 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 127 {
 128         int pos = commit_graft_pos(graft->sha1);
 129
 130         if (0 <= pos) {
 131                 if (ignore_dups)
 132                         free(graft);
 133                 else {
 134                         free(commit_graft[pos]);
 135                         commit_graft[pos] = graft;
 136                 }
 137                 return 1;
 138         }
 139         pos = -pos - 1;
 140         if (commit_graft_alloc <= ++commit_graft_nr) {
 141                 commit_graft_alloc = alloc_nr(commit_graft_alloc);
 142                 commit_graft = xrealloc(commit_graft,
 143                                         sizeof(*commit_graft) *
 144                                         commit_graft_alloc);
 145         }
 146         if (pos < commit_graft_nr)
 147                 memmove(commit_graft + pos + 1,
 148                         commit_graft + pos,
 149                         (commit_graft_nr - pos - 1) *
 150                         sizeof(*commit_graft));
 151         commit_graft[pos] = graft;
 152         return 0;
 153 }
 154
 155 struct commit_graft *read_graft_line(char *buf, int len)
 156 {
 157         /* The format is just "Commit Parent1 Parent2 ...\n" */
 158         int i;
 159         struct commit_graft *graft = NULL;
 160
 161         if (buf[len-1] == '\n')
 162                 buf[--len] = 0;
 163         if (buf[0] == '#' || buf[0] == '\0')
 164                 return NULL;
 165         if ((len + 1) % 41) {
 166         bad_graft_data:
 167                 error("bad graft data: %s", buf);
 168                 free(graft);
 169                 return NULL;
 170         }
 171         i = (len + 1) / 41 - 1;
 172         graft = xmalloc(sizeof(*graft) + 20 * i);
 173         graft->nr_parent = i;
 174         if (get_sha1_hex(buf, graft->sha1))
 175                 goto bad_graft_data;
 176         for (i = 40; i < len; i += 41) {
 177                 if (buf[i] != ' ')
 178                         goto bad_graft_data;
 179                 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 180                         goto bad_graft_data;
 181         }
 182         return graft;
 183 }
 184
 185 int read_graft_file(const char *graft_file)
 186 {
 187         FILE *fp = fopen(graft_file, "r");
 188         char buf[1024];
 189         if (!fp)
 190                 return -1;
 191         while (fgets(buf, sizeof(buf), fp)) {
 192                 /* The format is just "Commit Parent1 Parent2 ...\n" */
 193                 int len = strlen(buf);
 194                 struct commit_graft *graft = read_graft_line(buf, len);
 195                 if (!graft)
 196                         continue;
 197                 if (register_commit_graft(graft, 1))
 198                         error("duplicate graft data: %s", buf);
 199         }
 200         fclose(fp);
 201         return 0;
 202 }
 203
 204 static void prepare_commit_graft(void)
 205 {
 206         static int commit_graft_prepared;
 207         char *graft_file;
 208
 209         if (commit_graft_prepared)
 210                 return;
 211         graft_file = get_graft_file();
 212         read_graft_file(graft_file);
 213         commit_graft_prepared = 1;
 214 }
 215
 216 static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 217 {
 218         int pos;
 219         prepare_commit_graft();
 220         pos = commit_graft_pos(sha1);
 221         if (pos < 0)
 222                 return NULL;
 223         return commit_graft[pos];
 224 }
 225
 226 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 227 {
 228         char *bufptr = buffer;
 229         unsigned char parent[20];
 230         struct commit_list **pptr;
 231         struct commit_graft *graft;
 232         unsigned n_refs = 0;
 233
 234         if (item->object.parsed)
 235                 return 0;
 236         item->object.parsed = 1;
 237         if (memcmp(bufptr, "tree ", 5))
 238                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 239         if (get_sha1_hex(bufptr + 5, parent) < 0)
 240                 return error("bad tree pointer in commit %s",
 241                              sha1_to_hex(item->object.sha1));
 242         item->tree = lookup_tree(parent);
 243         if (item->tree)
 244                 n_refs++;
 245         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 246         pptr = &item->parents;
 247
 248         graft = lookup_commit_graft(item->object.sha1);
 249         while (!memcmp(bufptr, "parent ", 7)) {
 250                 struct commit *new_parent;
 251
 252                 if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 253                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 254                 bufptr += 48;
 255                 if (graft)
 256                         continue;
 257                 new_parent = lookup_commit(parent);
 258                 if (new_parent) {
 259                         pptr = &commit_list_insert(new_parent, pptr)->next;
 260                         n_refs++;
 261                 }
 262         }
 263         if (graft) {
 264                 int i;
 265                 struct commit *new_parent;
 266                 for (i = 0; i < graft->nr_parent; i++) {
 267                         new_parent = lookup_commit(graft->parent[i]);
 268                         if (!new_parent)
 269                                 continue;
 270                         pptr = &commit_list_insert(new_parent, pptr)->next;
 271                         n_refs++;
 272                 }
 273         }
 274         item->date = parse_commit_date(bufptr);
 275
 276         if (track_object_refs) {
 277                 unsigned i = 0;
 278                 struct commit_list *p;
 279                 struct object_refs *refs = alloc_object_refs(n_refs);
 280                 if (item->tree)
 281                         refs->ref[i++] = &item->tree->object;
 282                 for (p = item->parents; p; p = p->next)
 283                         refs->ref[i++] = &p->item->object;
 284                 set_object_refs(&item->object, refs);
 285         }
 286
 287         return 0;
 288 }
 289
 290 int parse_commit(struct commit *item)
 291 {
 292         char type[20];
 293         void *buffer;
 294         unsigned long size;
 295         int ret;
 296
 297         if (item->object.parsed)
 298                 return 0;
 299         buffer = read_sha1_file(item->object.sha1, type, &size);
 300         if (!buffer)
 301                 return error("Could not read %s",
 302                              sha1_to_hex(item->object.sha1));
 303         if (strcmp(type, commit_type)) {
 304                 free(buffer);
 305                 return error("Object %s not a commit",
 306                              sha1_to_hex(item->object.sha1));
 307         }
 308         ret = parse_commit_buffer(item, buffer, size);
 309         if (save_commit_buffer && !ret) {
 310                 item->buffer = buffer;
 311                 return 0;
 312         }
 313         free(buffer);
 314         return ret;
 315 }
 316
 317 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 318 {
 319         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 320         new_list->item = item;
 321         new_list->next = *list_p;
 322         *list_p = new_list;
 323         return new_list;
 324 }
 325
 326 void free_commit_list(struct commit_list *list)
 327 {
 328         while (list) {
 329                 struct commit_list *temp = list;
 330                 list = temp->next;
 331                 free(temp);
 332         }
 333 }
 334
 335 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 336 {
 337         struct commit_list **pp = list;
 338         struct commit_list *p;
 339         while ((p = *pp) != NULL) {
 340                 if (p->item->date < item->date) {
 341                         break;
 342                 }
 343                 pp = &p->next;
 344         }
 345         return commit_list_insert(item, pp);
 346 }
 347
 348
 349 void sort_by_date(struct commit_list **list)
 350 {
 351         struct commit_list *ret = NULL;
 352         while (*list) {
 353                 insert_by_date((*list)->item, &ret);
 354                 *list = (*list)->next;
 355         }
 356         *list = ret;
 357 }
 358
 359 struct commit *pop_most_recent_commit(struct commit_list **list,
 360                                       unsigned int mark)
 361 {
 362         struct commit *ret = (*list)->item;
 363         struct commit_list *parents = ret->parents;
 364         struct commit_list *old = *list;
 365
 366         *list = (*list)->next;
 367         free(old);
 368
 369         while (parents) {
 370                 struct commit *commit = parents->item;
 371                 parse_commit(commit);
 372                 if (!(commit->object.flags & mark)) {
 373                         commit->object.flags |= mark;
 374                         insert_by_date(commit, list);
 375                 }
 376                 parents = parents->next;
 377         }
 378         return ret;
 379 }
 380
 381 void clear_commit_marks(struct commit *commit, unsigned int mark)
 382 {
 383         struct commit_list *parents;
 384
 385         parents = commit->parents;
 386         commit->object.flags &= ~mark;
 387         while (parents) {
 388                 struct commit *parent = parents->item;
 389                 if (parent && parent->object.parsed &&
 390                     (parent->object.flags & mark))
 391                         clear_commit_marks(parent, mark);
 392                 parents = parents->next;
 393         }
 394 }
 395
 396 /*
 397  * Generic support for pretty-printing the header
 398  */
 399 static int get_one_line(const char *msg, unsigned long len)
 400 {
 401         int ret = 0;
 402
 403         while (len--) {
 404                 char c = *msg++;
 405                 if (!c)
 406                         break;
 407                 ret++;
 408                 if (c == '\n')
 409                         break;
 410         }
 411         return ret;
 412 }
 413
 414 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 415 {
 416         char *date;
 417         int namelen;
 418         unsigned long time;
 419         int tz, ret;
 420         const char *filler = "    ";
 421
 422         if (fmt == CMIT_FMT_ONELINE)
 423                 return 0;
 424         date = strchr(line, '>');
 425         if (!date)
 426                 return 0;
 427         namelen = ++date - line;
 428         time = strtoul(date, &date, 10);
 429         tz = strtol(date, NULL, 10);
 430
 431         ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 432                       (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 433                       filler, namelen, line);
 434         switch (fmt) {
 435         case CMIT_FMT_MEDIUM:
 436                 ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 437                 break;
 438         case CMIT_FMT_FULLER:
 439                 ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 440                 break;
 441         default:
 442                 /* notin' */
 443                 break;
 444         }
 445         return ret;
 446 }
 447
 448 static int is_empty_line(const char *line, int len)
 449 {
 450         while (len && isspace(line[len-1]))
 451                 len--;
 452         return !len;
 453 }
 454
 455 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 456 {
 457         struct commit_list *parent = commit->parents;
 458         int offset;
 459
 460         if ((fmt == CMIT_FMT_ONELINE) || !parent || !parent->next)
 461                 return 0;
 462
 463         offset = sprintf(buf, "Merge:");
 464
 465         while (parent) {
 466                 struct commit *p = parent->item;
 467                 const char *hex = abbrev
 468                         ? find_unique_abbrev(p->object.sha1, abbrev)
 469                         : sha1_to_hex(p->object.sha1);
 470                 char *dots = (abbrev && strlen(hex) != 40) ? "..." : "";
 471                 parent = parent->next;
 472
 473                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 474         }
 475         buf[offset++] = '\n';
 476         return offset;
 477 }
 478
 479 unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit, unsigned long len, char *buf, unsigned long space, int abbrev)
 480 {
 481         int hdr = 1, body = 0;
 482         unsigned long offset = 0;
 483         int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 484         int parents_shown = 0;
 485         const char *msg = commit->buffer;
 486
 487         for (;;) {
 488                 const char *line = msg;
 489                 int linelen = get_one_line(msg, len);
 490
 491                 if (!linelen)
 492                         break;
 493
 494                 /*
 495                  * We want some slop for indentation and a possible
 496                  * final "...". Thus the "+ 20".
 497                  */
 498                 if (offset + linelen + 20 > space) {
 499                         memcpy(buf + offset, "    ...\n", 8);
 500                         offset += 8;
 501                         break;
 502                 }
 503
 504                 msg += linelen;
 505                 len -= linelen;
 506                 if (hdr) {
 507                         if (linelen == 1) {
 508                                 hdr = 0;
 509                                 if (fmt != CMIT_FMT_ONELINE)
 510                                         buf[offset++] = '\n';
 511                                 continue;
 512                         }
 513                         if (fmt == CMIT_FMT_RAW) {
 514                                 memcpy(buf + offset, line, linelen);
 515                                 offset += linelen;
 516                                 continue;
 517                         }
 518                         if (!memcmp(line, "parent ", 7)) {
 519                                 if (linelen != 48)
 520                                         die("bad parent line in commit");
 521                                 continue;
 522                         }
 523
 524                         if (!parents_shown) {
 525                                 offset += add_merge_info(fmt, buf + offset,
 526                                                          commit, abbrev);
 527                                 parents_shown = 1;
 528                                 continue;
 529                         }
 530                         /*
 531                          * MEDIUM == DEFAULT shows only author with dates.
 532                          * FULL shows both authors but not dates.
 533                          * FULLER shows both authors and dates.
 534                          */
 535                         if (!memcmp(line, "author ", 7))
 536                                 offset += add_user_info("Author", fmt,
 537                                                         buf + offset,
 538                                                         line + 7);
 539                         if (!memcmp(line, "committer ", 10) &&
 540                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 541                                 offset += add_user_info("Commit", fmt,
 542                                                         buf + offset,
 543                                                         line + 10);
 544                         continue;
 545                 }
 546
 547                 if (is_empty_line(line, linelen)) {
 548                         if (!body)
 549                                 continue;
 550                         if (fmt == CMIT_FMT_SHORT)
 551                                 break;
 552                 } else {
 553                         body = 1;
 554                 }
 555
 556                 memset(buf + offset, ' ', indent);
 557                 memcpy(buf + offset + indent, line, linelen);
 558                 offset += linelen + indent;
 559                 if (fmt == CMIT_FMT_ONELINE)
 560                         break;
 561         }
 562         while (offset && isspace(buf[offset-1]))
 563                 offset--;
 564         /* Make sure there is an EOLN for the non-oneline case */
 565         if (fmt != CMIT_FMT_ONELINE)
 566                 buf[offset++] = '\n';
 567         buf[offset] = '\0';
 568         return offset;
 569 }
 570
 571 struct commit *pop_commit(struct commit_list **stack)
 572 {
 573         struct commit_list *top = *stack;
 574         struct commit *item = top ? top->item : NULL;
 575
 576         if (top) {
 577                 *stack = top->next;
 578                 free(top);
 579         }
 580         return item;
 581 }
 582
 583 int count_parents(struct commit * commit)
 584 {
 585         int count = 0;
 586         struct commit_list * parents = commit->parents;
 587         for (count=0;parents; parents=parents->next,count++)
 588           ;
 589         return count;
 590 }
 591
 592 void topo_sort_default_setter(struct commit *c, void *data)
 593 {
 594         c->object.util = data;
 595 }
 596
 597 void *topo_sort_default_getter(struct commit *c)
 598 {
 599         return c->object.util;
 600 }
 601
 602 /*
 603  * Performs an in-place topological sort on the list supplied.
 604  */
 605 void sort_in_topological_order(struct commit_list ** list, int lifo)
 606 {
 607         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 608                                      topo_sort_default_getter);
 609 }
 610
 611 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 612                                   topo_sort_set_fn_t setter,
 613                                   topo_sort_get_fn_t getter)
 614 {
 615         struct commit_list * next = *list;
 616         struct commit_list * work = NULL, **insert;
 617         struct commit_list ** pptr = list;
 618         struct sort_node * nodes;
 619         struct sort_node * next_nodes;
 620         int count = 0;
 621
 622         /* determine the size of the list */
 623         while (next) {
 624                 next = next->next;
 625                 count++;
 626         }
 627
 628         if (!count)
 629                 return;
 630         /* allocate an array to help sort the list */
 631         nodes = xcalloc(count, sizeof(*nodes));
 632         /* link the list to the array */
 633         next_nodes = nodes;
 634         next=*list;
 635         while (next) {
 636                 next_nodes->list_item = next;
 637                 setter(next->item, next_nodes);
 638                 next_nodes++;
 639                 next = next->next;
 640         }
 641         /* update the indegree */
 642         next=*list;
 643         while (next) {
 644                 struct commit_list * parents = next->item->parents;
 645                 while (parents) {
 646                         struct commit * parent=parents->item;
 647                         struct sort_node * pn = (struct sort_node *) getter(parent);
 648
 649                         if (pn)
 650                                 pn->indegree++;
 651                         parents=parents->next;
 652                 }
 653                 next=next->next;
 654         }
 655         /*
 656          * find the tips
 657          *
 658          * tips are nodes not reachable from any other node in the list
 659          *
 660          * the tips serve as a starting set for the work queue.
 661          */
 662         next=*list;
 663         insert = &work;
 664         while (next) {
 665                 struct sort_node * node = (struct sort_node *) getter(next->item);
 666
 667                 if (node->indegree == 0) {
 668                         insert = &commit_list_insert(next->item, insert)->next;
 669                 }
 670                 next=next->next;
 671         }
 672
 673         /* process the list in topological order */
 674         if (!lifo)
 675                 sort_by_date(&work);
 676         while (work) {
 677                 struct commit * work_item = pop_commit(&work);
 678                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
 679                 struct commit_list * parents = work_item->parents;
 680
 681                 while (parents) {
 682                         struct commit * parent=parents->item;
 683                         struct sort_node * pn = (struct sort_node *) getter(parent);
 684
 685                         if (pn) {
 686                                 /*
 687                                  * parents are only enqueued for emission
 688                                  * when all their children have been emitted thereby
 689                                  * guaranteeing topological order.
 690                                  */
 691                                 pn->indegree--;
 692                                 if (!pn->indegree) {
 693                                         if (!lifo)
 694                                                 insert_by_date(parent, &work);
 695                                         else
 696                                                 commit_list_insert(parent, &work);
 697                                 }
 698                         }
 699                         parents=parents->next;
 700                 }
 701                 /*
 702                  * work_item is a commit all of whose children
 703                  * have already been emitted. we can emit it now.
 704                  */
 705                 *pptr = work_node->list_item;
 706                 pptr = &(*pptr)->next;
 707                 *pptr = NULL;
 708                 setter(work_item, NULL);
 709         }
 710         free(nodes);
 711 }