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] == '#')
 164                 return 0;
 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 (register_commit_graft(graft, 1))
 196                         error("duplicate graft data: %s", buf);
 197         }
 198         fclose(fp);
 199         return 0;
 200 }
 201
 202 static void prepare_commit_graft(void)
 203 {
 204         static int commit_graft_prepared;
 205         char *graft_file;
 206
 207         if (commit_graft_prepared)
 208                 return;
 209         graft_file = get_graft_file();
 210         read_graft_file(graft_file);
 211         commit_graft_prepared = 1;
 212 }
 213
 214 static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 215 {
 216         int pos;
 217         prepare_commit_graft();
 218         pos = commit_graft_pos(sha1);
 219         if (pos < 0)
 220                 return NULL;
 221         return commit_graft[pos];
 222 }
 223
 224 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 225 {
 226         char *bufptr = buffer;
 227         unsigned char parent[20];
 228         struct commit_list **pptr;
 229         struct commit_graft *graft;
 230         unsigned n_refs = 0;
 231
 232         if (item->object.parsed)
 233                 return 0;
 234         item->object.parsed = 1;
 235         if (memcmp(bufptr, "tree ", 5))
 236                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 237         if (get_sha1_hex(bufptr + 5, parent) < 0)
 238                 return error("bad tree pointer in commit %s",
 239                              sha1_to_hex(item->object.sha1));
 240         item->tree = lookup_tree(parent);
 241         if (item->tree)
 242                 n_refs++;
 243         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 244         pptr = &item->parents;
 245
 246         graft = lookup_commit_graft(item->object.sha1);
 247         while (!memcmp(bufptr, "parent ", 7)) {
 248                 struct commit *new_parent;
 249
 250                 if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 251                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 252                 bufptr += 48;
 253                 if (graft)
 254                         continue;
 255                 new_parent = lookup_commit(parent);
 256                 if (new_parent) {
 257                         pptr = &commit_list_insert(new_parent, pptr)->next;
 258                         n_refs++;
 259                 }
 260         }
 261         if (graft) {
 262                 int i;
 263                 struct commit *new_parent;
 264                 for (i = 0; i < graft->nr_parent; i++) {
 265                         new_parent = lookup_commit(graft->parent[i]);
 266                         if (!new_parent)
 267                                 continue;
 268                         pptr = &commit_list_insert(new_parent, pptr)->next;
 269                         n_refs++;
 270                 }
 271         }
 272         item->date = parse_commit_date(bufptr);
 273
 274         if (track_object_refs) {
 275                 unsigned i = 0;
 276                 struct commit_list *p;
 277                 struct object_refs *refs = alloc_object_refs(n_refs);
 278                 if (item->tree)
 279                         refs->ref[i++] = &item->tree->object;
 280                 for (p = item->parents; p; p = p->next)
 281                         refs->ref[i++] = &p->item->object;
 282                 set_object_refs(&item->object, refs);
 283         }
 284
 285         return 0;
 286 }
 287
 288 int parse_commit(struct commit *item)
 289 {
 290         char type[20];
 291         void *buffer;
 292         unsigned long size;
 293         int ret;
 294
 295         if (item->object.parsed)
 296                 return 0;
 297         buffer = read_sha1_file(item->object.sha1, type, &size);
 298         if (!buffer)
 299                 return error("Could not read %s",
 300                              sha1_to_hex(item->object.sha1));
 301         if (strcmp(type, commit_type)) {
 302                 free(buffer);
 303                 return error("Object %s not a commit",
 304                              sha1_to_hex(item->object.sha1));
 305         }
 306         ret = parse_commit_buffer(item, buffer, size);
 307         if (save_commit_buffer && !ret) {
 308                 item->buffer = buffer;
 309                 return 0;
 310         }
 311         free(buffer);
 312         return ret;
 313 }
 314
 315 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 316 {
 317         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 318         new_list->item = item;
 319         new_list->next = *list_p;
 320         *list_p = new_list;
 321         return new_list;
 322 }
 323
 324 void free_commit_list(struct commit_list *list)
 325 {
 326         while (list) {
 327                 struct commit_list *temp = list;
 328                 list = temp->next;
 329                 free(temp);
 330         }
 331 }
 332
 333 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 334 {
 335         struct commit_list **pp = list;
 336         struct commit_list *p;
 337         while ((p = *pp) != NULL) {
 338                 if (p->item->date < item->date) {
 339                         break;
 340                 }
 341                 pp = &p->next;
 342         }
 343         return commit_list_insert(item, pp);
 344 }
 345
 346
 347 void sort_by_date(struct commit_list **list)
 348 {
 349         struct commit_list *ret = NULL;
 350         while (*list) {
 351                 insert_by_date((*list)->item, &ret);
 352                 *list = (*list)->next;
 353         }
 354         *list = ret;
 355 }
 356
 357 struct commit *pop_most_recent_commit(struct commit_list **list,
 358                                       unsigned int mark)
 359 {
 360         struct commit *ret = (*list)->item;
 361         struct commit_list *parents = ret->parents;
 362         struct commit_list *old = *list;
 363
 364         *list = (*list)->next;
 365         free(old);
 366
 367         while (parents) {
 368                 struct commit *commit = parents->item;
 369                 parse_commit(commit);
 370                 if (!(commit->object.flags & mark)) {
 371                         commit->object.flags |= mark;
 372                         insert_by_date(commit, list);
 373                 }
 374                 parents = parents->next;
 375         }
 376         return ret;
 377 }
 378
 379 void clear_commit_marks(struct commit *commit, unsigned int mark)
 380 {
 381         struct commit_list *parents;
 382
 383         parents = commit->parents;
 384         commit->object.flags &= ~mark;
 385         while (parents) {
 386                 struct commit *parent = parents->item;
 387                 if (parent && parent->object.parsed &&
 388                     (parent->object.flags & mark))
 389                         clear_commit_marks(parent, mark);
 390                 parents = parents->next;
 391         }
 392 }
 393
 394 /*
 395  * Generic support for pretty-printing the header
 396  */
 397 static int get_one_line(const char *msg, unsigned long len)
 398 {
 399         int ret = 0;
 400
 401         while (len--) {
 402                 char c = *msg++;
 403                 ret++;
 404                 if (c == '\n')
 405                         break;
 406                 if (!c)
 407                         return 0;
 408         }
 409         return ret;
 410 }
 411
 412 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 413 {
 414         char *date;
 415         int namelen;
 416         unsigned long time;
 417         int tz, ret;
 418         const char *filler = "    ";
 419
 420         if (fmt == CMIT_FMT_ONELINE)
 421                 return 0;
 422         date = strchr(line, '>');
 423         if (!date)
 424                 return 0;
 425         namelen = ++date - line;
 426         time = strtoul(date, &date, 10);
 427         tz = strtol(date, NULL, 10);
 428
 429         ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 430                       (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 431                       filler, namelen, line);
 432         switch (fmt) {
 433         case CMIT_FMT_MEDIUM:
 434                 ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 435                 break;
 436         case CMIT_FMT_FULLER:
 437                 ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 438                 break;
 439         default:
 440                 /* notin' */
 441                 break;
 442         }
 443         return ret;
 444 }
 445
 446 static int is_empty_line(const char *line, int len)
 447 {
 448         while (len && isspace(line[len-1]))
 449                 len--;
 450         return !len;
 451 }
 452
 453 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 454 {
 455         struct commit_list *parent = commit->parents;
 456         int offset;
 457
 458         if ((fmt == CMIT_FMT_ONELINE) || !parent || !parent->next)
 459                 return 0;
 460
 461         offset = sprintf(buf, "Merge:");
 462
 463         while (parent) {
 464                 struct commit *p = parent->item;
 465                 const char *hex = abbrev
 466                         ? find_unique_abbrev(p->object.sha1, abbrev)
 467                         : sha1_to_hex(p->object.sha1);
 468                 char *dots = (abbrev && strlen(hex) != 40) ? "..." : "";
 469                 parent = parent->next;
 470
 471                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 472         }
 473         buf[offset++] = '\n';
 474         return offset;
 475 }
 476
 477 unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit, unsigned long len, char *buf, unsigned long space, int abbrev)
 478 {
 479         int hdr = 1, body = 0;
 480         unsigned long offset = 0;
 481         int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 482         int parents_shown = 0;
 483         const char *msg = commit->buffer;
 484
 485         for (;;) {
 486                 const char *line = msg;
 487                 int linelen = get_one_line(msg, len);
 488
 489                 if (!linelen)
 490                         break;
 491
 492                 /*
 493                  * We want some slop for indentation and a possible
 494                  * final "...". Thus the "+ 20".
 495                  */
 496                 if (offset + linelen + 20 > space) {
 497                         memcpy(buf + offset, "    ...\n", 8);
 498                         offset += 8;
 499                         break;
 500                 }
 501
 502                 msg += linelen;
 503                 len -= linelen;
 504                 if (hdr) {
 505                         if (linelen == 1) {
 506                                 hdr = 0;
 507                                 if (fmt != CMIT_FMT_ONELINE)
 508                                         buf[offset++] = '\n';
 509                                 continue;
 510                         }
 511                         if (fmt == CMIT_FMT_RAW) {
 512                                 memcpy(buf + offset, line, linelen);
 513                                 offset += linelen;
 514                                 continue;
 515                         }
 516                         if (!memcmp(line, "parent ", 7)) {
 517                                 if (linelen != 48)
 518                                         die("bad parent line in commit");
 519                                 continue;
 520                         }
 521
 522                         if (!parents_shown) {
 523                                 offset += add_merge_info(fmt, buf + offset,
 524                                                          commit, abbrev);
 525                                 parents_shown = 1;
 526                                 continue;
 527                         }
 528                         /*
 529                          * MEDIUM == DEFAULT shows only author with dates.
 530                          * FULL shows both authors but not dates.
 531                          * FULLER shows both authors and dates.
 532                          */
 533                         if (!memcmp(line, "author ", 7))
 534                                 offset += add_user_info("Author", fmt,
 535                                                         buf + offset,
 536                                                         line + 7);
 537                         if (!memcmp(line, "committer ", 10) &&
 538                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 539                                 offset += add_user_info("Commit", fmt,
 540                                                         buf + offset,
 541                                                         line + 10);
 542                         continue;
 543                 }
 544
 545                 if (is_empty_line(line, linelen)) {
 546                         if (!body)
 547                                 continue;
 548                         if (fmt == CMIT_FMT_SHORT)
 549                                 break;
 550                 } else {
 551                         body = 1;
 552                 }
 553
 554                 memset(buf + offset, ' ', indent);
 555                 memcpy(buf + offset + indent, line, linelen);
 556                 offset += linelen + indent;
 557                 if (fmt == CMIT_FMT_ONELINE)
 558                         break;
 559         }
 560         if (fmt == CMIT_FMT_ONELINE) {
 561                 /* We do not want the terminating newline */
 562                 if (buf[offset - 1] == '\n')
 563                         offset--;
 564         }
 565         else {
 566                 /* Make sure there is an EOLN */
 567                 if (buf[offset - 1] != '\n')
 568                         buf[offset++] = '\n';
 569         }
 570         buf[offset] = '\0';
 571         return offset;
 572 }
 573
 574 struct commit *pop_commit(struct commit_list **stack)
 575 {
 576         struct commit_list *top = *stack;
 577         struct commit *item = top ? top->item : NULL;
 578
 579         if (top) {
 580                 *stack = top->next;
 581                 free(top);
 582         }
 583         return item;
 584 }
 585
 586 int count_parents(struct commit * commit)
 587 {
 588         int count = 0;
 589         struct commit_list * parents = commit->parents;
 590         for (count=0;parents; parents=parents->next,count++)
 591           ;
 592         return count;
 593 }
 594
 595 void topo_sort_default_setter(struct commit *c, void *data)
 596 {
 597         c->object.util = data;
 598 }
 599
 600 void *topo_sort_default_getter(struct commit *c)
 601 {
 602         return c->object.util;
 603 }
 604
 605 /*
 606  * Performs an in-place topological sort on the list supplied.
 607  */
 608 void sort_in_topological_order(struct commit_list ** list, int lifo)
 609 {
 610         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 611                                      topo_sort_default_getter);
 612 }
 613
 614 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 615                                   topo_sort_set_fn_t setter,
 616                                   topo_sort_get_fn_t getter)
 617 {
 618         struct commit_list * next = *list;
 619         struct commit_list * work = NULL, **insert;
 620         struct commit_list ** pptr = list;
 621         struct sort_node * nodes;
 622         struct sort_node * next_nodes;
 623         int count = 0;
 624
 625         /* determine the size of the list */
 626         while (next) {
 627                 next = next->next;
 628                 count++;
 629         }
 630
 631         if (!count)
 632                 return;
 633         /* allocate an array to help sort the list */
 634         nodes = xcalloc(count, sizeof(*nodes));
 635         /* link the list to the array */
 636         next_nodes = nodes;
 637         next=*list;
 638         while (next) {
 639                 next_nodes->list_item = next;
 640                 setter(next->item, next_nodes);
 641                 next_nodes++;
 642                 next = next->next;
 643         }
 644         /* update the indegree */
 645         next=*list;
 646         while (next) {
 647                 struct commit_list * parents = next->item->parents;
 648                 while (parents) {
 649                         struct commit * parent=parents->item;
 650                         struct sort_node * pn = (struct sort_node *) getter(parent);
 651
 652                         if (pn)
 653                                 pn->indegree++;
 654                         parents=parents->next;
 655                 }
 656                 next=next->next;
 657         }
 658         /*
 659          * find the tips
 660          *
 661          * tips are nodes not reachable from any other node in the list
 662          *
 663          * the tips serve as a starting set for the work queue.
 664          */
 665         next=*list;
 666         insert = &work;
 667         while (next) {
 668                 struct sort_node * node = (struct sort_node *) getter(next->item);
 669
 670                 if (node->indegree == 0) {
 671                         insert = &commit_list_insert(next->item, insert)->next;
 672                 }
 673                 next=next->next;
 674         }
 675
 676         /* process the list in topological order */
 677         if (!lifo)
 678                 sort_by_date(&work);
 679         while (work) {
 680                 struct commit * work_item = pop_commit(&work);
 681                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
 682                 struct commit_list * parents = work_item->parents;
 683
 684                 while (parents) {
 685                         struct commit * parent=parents->item;
 686                         struct sort_node * pn = (struct sort_node *) getter(parent);
 687
 688                         if (pn) {
 689                                 /*
 690                                  * parents are only enqueued for emission
 691                                  * when all their children have been emitted thereby
 692                                  * guaranteeing topological order.
 693                                  */
 694                                 pn->indegree--;
 695                                 if (!pn->indegree) {
 696                                         if (!lifo)
 697                                                 insert_by_date(parent, &work);
 698                                         else
 699                                                 commit_list_insert(parent, &work);
 700                                 }
 701                         }
 702                         parents=parents->next;
 703                 }
 704                 /*
 705                  * work_item is a commit all of whose children
 706                  * have already been emitted. we can emit it now.
 707                  */
 708                 *pptr = work_node->list_item;
 709                 pptr = &(*pptr)->next;
 710                 *pptr = NULL;
 711                 setter(work_item, NULL);
 712         }
 713         free(nodes);
 714 }