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, "=email"))
  40                 return CMIT_FMT_EMAIL;
  41         if (!strcmp(arg, "=oneline"))
  42                 return CMIT_FMT_ONELINE;
  43         die("invalid --pretty format");
  44 }
  45
  46 static struct commit *check_commit(struct object *obj,
  47                                    const unsigned char *sha1,
  48                                    int quiet)
  49 {
  50         if (obj->type != commit_type) {
  51                 if (!quiet)
  52                         error("Object %s is a %s, not a commit",
  53                               sha1_to_hex(sha1), obj->type);
  54                 return NULL;
  55         }
  56         return (struct commit *) obj;
  57 }
  58
  59 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  60                                               int quiet)
  61 {
  62         struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  63
  64         if (!obj)
  65                 return NULL;
  66         return check_commit(obj, sha1, quiet);
  67 }
  68
  69 struct commit *lookup_commit_reference(const unsigned char *sha1)
  70 {
  71         return lookup_commit_reference_gently(sha1, 0);
  72 }
  73
  74 struct commit *lookup_commit(const unsigned char *sha1)
  75 {
  76         struct object *obj = lookup_object(sha1);
  77         if (!obj) {
  78                 struct commit *ret = xcalloc(1, sizeof(struct commit));
  79                 created_object(sha1, &ret->object);
  80                 ret->object.type = commit_type;
  81                 return ret;
  82         }
  83         if (!obj->type)
  84                 obj->type = commit_type;
  85         return check_commit(obj, sha1, 0);
  86 }
  87
  88 static unsigned long parse_commit_date(const char *buf)
  89 {
  90         unsigned long date;
  91
  92         if (memcmp(buf, "author", 6))
  93                 return 0;
  94         while (*buf++ != '\n')
  95                 /* nada */;
  96         if (memcmp(buf, "committer", 9))
  97                 return 0;
  98         while (*buf++ != '>')
  99                 /* nada */;
 100         date = strtoul(buf, NULL, 10);
 101         if (date == ULONG_MAX)
 102                 date = 0;
 103         return date;
 104 }
 105
 106 static struct commit_graft **commit_graft;
 107 static int commit_graft_alloc, commit_graft_nr;
 108
 109 static int commit_graft_pos(const unsigned char *sha1)
 110 {
 111         int lo, hi;
 112         lo = 0;
 113         hi = commit_graft_nr;
 114         while (lo < hi) {
 115                 int mi = (lo + hi) / 2;
 116                 struct commit_graft *graft = commit_graft[mi];
 117                 int cmp = memcmp(sha1, graft->sha1, 20);
 118                 if (!cmp)
 119                         return mi;
 120                 if (cmp < 0)
 121                         hi = mi;
 122                 else
 123                         lo = mi + 1;
 124         }
 125         return -lo - 1;
 126 }
 127
 128 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 129 {
 130         int pos = commit_graft_pos(graft->sha1);
 131
 132         if (0 <= pos) {
 133                 if (ignore_dups)
 134                         free(graft);
 135                 else {
 136                         free(commit_graft[pos]);
 137                         commit_graft[pos] = graft;
 138                 }
 139                 return 1;
 140         }
 141         pos = -pos - 1;
 142         if (commit_graft_alloc <= ++commit_graft_nr) {
 143                 commit_graft_alloc = alloc_nr(commit_graft_alloc);
 144                 commit_graft = xrealloc(commit_graft,
 145                                         sizeof(*commit_graft) *
 146                                         commit_graft_alloc);
 147         }
 148         if (pos < commit_graft_nr)
 149                 memmove(commit_graft + pos + 1,
 150                         commit_graft + pos,
 151                         (commit_graft_nr - pos - 1) *
 152                         sizeof(*commit_graft));
 153         commit_graft[pos] = graft;
 154         return 0;
 155 }
 156
 157 struct commit_graft *read_graft_line(char *buf, int len)
 158 {
 159         /* The format is just "Commit Parent1 Parent2 ...\n" */
 160         int i;
 161         struct commit_graft *graft = NULL;
 162
 163         if (buf[len-1] == '\n')
 164                 buf[--len] = 0;
 165         if (buf[0] == '#' || buf[0] == '\0')
 166                 return NULL;
 167         if ((len + 1) % 41) {
 168         bad_graft_data:
 169                 error("bad graft data: %s", buf);
 170                 free(graft);
 171                 return NULL;
 172         }
 173         i = (len + 1) / 41 - 1;
 174         graft = xmalloc(sizeof(*graft) + 20 * i);
 175         graft->nr_parent = i;
 176         if (get_sha1_hex(buf, graft->sha1))
 177                 goto bad_graft_data;
 178         for (i = 40; i < len; i += 41) {
 179                 if (buf[i] != ' ')
 180                         goto bad_graft_data;
 181                 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 182                         goto bad_graft_data;
 183         }
 184         return graft;
 185 }
 186
 187 int read_graft_file(const char *graft_file)
 188 {
 189         FILE *fp = fopen(graft_file, "r");
 190         char buf[1024];
 191         if (!fp)
 192                 return -1;
 193         while (fgets(buf, sizeof(buf), fp)) {
 194                 /* The format is just "Commit Parent1 Parent2 ...\n" */
 195                 int len = strlen(buf);
 196                 struct commit_graft *graft = read_graft_line(buf, len);
 197                 if (!graft)
 198                         continue;
 199                 if (register_commit_graft(graft, 1))
 200                         error("duplicate graft data: %s", buf);
 201         }
 202         fclose(fp);
 203         return 0;
 204 }
 205
 206 static void prepare_commit_graft(void)
 207 {
 208         static int commit_graft_prepared;
 209         char *graft_file;
 210
 211         if (commit_graft_prepared)
 212                 return;
 213         graft_file = get_graft_file();
 214         read_graft_file(graft_file);
 215         commit_graft_prepared = 1;
 216 }
 217
 218 static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 219 {
 220         int pos;
 221         prepare_commit_graft();
 222         pos = commit_graft_pos(sha1);
 223         if (pos < 0)
 224                 return NULL;
 225         return commit_graft[pos];
 226 }
 227
 228 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 229 {
 230         char *bufptr = buffer;
 231         unsigned char parent[20];
 232         struct commit_list **pptr;
 233         struct commit_graft *graft;
 234         unsigned n_refs = 0;
 235
 236         if (item->object.parsed)
 237                 return 0;
 238         item->object.parsed = 1;
 239         if (memcmp(bufptr, "tree ", 5))
 240                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 241         if (get_sha1_hex(bufptr + 5, parent) < 0)
 242                 return error("bad tree pointer in commit %s",
 243                              sha1_to_hex(item->object.sha1));
 244         item->tree = lookup_tree(parent);
 245         if (item->tree)
 246                 n_refs++;
 247         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 248         pptr = &item->parents;
 249
 250         graft = lookup_commit_graft(item->object.sha1);
 251         while (!memcmp(bufptr, "parent ", 7)) {
 252                 struct commit *new_parent;
 253
 254                 if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 255                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 256                 bufptr += 48;
 257                 if (graft)
 258                         continue;
 259                 new_parent = lookup_commit(parent);
 260                 if (new_parent) {
 261                         pptr = &commit_list_insert(new_parent, pptr)->next;
 262                         n_refs++;
 263                 }
 264         }
 265         if (graft) {
 266                 int i;
 267                 struct commit *new_parent;
 268                 for (i = 0; i < graft->nr_parent; i++) {
 269                         new_parent = lookup_commit(graft->parent[i]);
 270                         if (!new_parent)
 271                                 continue;
 272                         pptr = &commit_list_insert(new_parent, pptr)->next;
 273                         n_refs++;
 274                 }
 275         }
 276         item->date = parse_commit_date(bufptr);
 277
 278         if (track_object_refs) {
 279                 unsigned i = 0;
 280                 struct commit_list *p;
 281                 struct object_refs *refs = alloc_object_refs(n_refs);
 282                 if (item->tree)
 283                         refs->ref[i++] = &item->tree->object;
 284                 for (p = item->parents; p; p = p->next)
 285                         refs->ref[i++] = &p->item->object;
 286                 set_object_refs(&item->object, refs);
 287         }
 288
 289         return 0;
 290 }
 291
 292 int parse_commit(struct commit *item)
 293 {
 294         char type[20];
 295         void *buffer;
 296         unsigned long size;
 297         int ret;
 298
 299         if (item->object.parsed)
 300                 return 0;
 301         buffer = read_sha1_file(item->object.sha1, type, &size);
 302         if (!buffer)
 303                 return error("Could not read %s",
 304                              sha1_to_hex(item->object.sha1));
 305         if (strcmp(type, commit_type)) {
 306                 free(buffer);
 307                 return error("Object %s not a commit",
 308                              sha1_to_hex(item->object.sha1));
 309         }
 310         ret = parse_commit_buffer(item, buffer, size);
 311         if (save_commit_buffer && !ret) {
 312                 item->buffer = buffer;
 313                 return 0;
 314         }
 315         free(buffer);
 316         return ret;
 317 }
 318
 319 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 320 {
 321         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 322         new_list->item = item;
 323         new_list->next = *list_p;
 324         *list_p = new_list;
 325         return new_list;
 326 }
 327
 328 void free_commit_list(struct commit_list *list)
 329 {
 330         while (list) {
 331                 struct commit_list *temp = list;
 332                 list = temp->next;
 333                 free(temp);
 334         }
 335 }
 336
 337 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 338 {
 339         struct commit_list **pp = list;
 340         struct commit_list *p;
 341         while ((p = *pp) != NULL) {
 342                 if (p->item->date < item->date) {
 343                         break;
 344                 }
 345                 pp = &p->next;
 346         }
 347         return commit_list_insert(item, pp);
 348 }
 349
 350
 351 void sort_by_date(struct commit_list **list)
 352 {
 353         struct commit_list *ret = NULL;
 354         while (*list) {
 355                 insert_by_date((*list)->item, &ret);
 356                 *list = (*list)->next;
 357         }
 358         *list = ret;
 359 }
 360
 361 struct commit *pop_most_recent_commit(struct commit_list **list,
 362                                       unsigned int mark)
 363 {
 364         struct commit *ret = (*list)->item;
 365         struct commit_list *parents = ret->parents;
 366         struct commit_list *old = *list;
 367
 368         *list = (*list)->next;
 369         free(old);
 370
 371         while (parents) {
 372                 struct commit *commit = parents->item;
 373                 parse_commit(commit);
 374                 if (!(commit->object.flags & mark)) {
 375                         commit->object.flags |= mark;
 376                         insert_by_date(commit, list);
 377                 }
 378                 parents = parents->next;
 379         }
 380         return ret;
 381 }
 382
 383 void clear_commit_marks(struct commit *commit, unsigned int mark)
 384 {
 385         struct commit_list *parents;
 386
 387         parents = commit->parents;
 388         commit->object.flags &= ~mark;
 389         while (parents) {
 390                 struct commit *parent = parents->item;
 391                 if (parent && parent->object.parsed &&
 392                     (parent->object.flags & mark))
 393                         clear_commit_marks(parent, mark);
 394                 parents = parents->next;
 395         }
 396 }
 397
 398 /*
 399  * Generic support for pretty-printing the header
 400  */
 401 static int get_one_line(const char *msg, unsigned long len)
 402 {
 403         int ret = 0;
 404
 405         while (len--) {
 406                 char c = *msg++;
 407                 if (!c)
 408                         break;
 409                 ret++;
 410                 if (c == '\n')
 411                         break;
 412         }
 413         return ret;
 414 }
 415
 416 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 417 {
 418         char *date;
 419         int namelen;
 420         unsigned long time;
 421         int tz, ret;
 422         const char *filler = "    ";
 423
 424         if (fmt == CMIT_FMT_ONELINE)
 425                 return 0;
 426         date = strchr(line, '>');
 427         if (!date)
 428                 return 0;
 429         namelen = ++date - line;
 430         time = strtoul(date, &date, 10);
 431         tz = strtol(date, NULL, 10);
 432
 433         if (fmt == CMIT_FMT_EMAIL) {
 434                 what = "From";
 435                 filler = "";
 436         }
 437         ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 438                       (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 439                       filler, namelen, line);
 440         switch (fmt) {
 441         case CMIT_FMT_MEDIUM:
 442                 ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 443                 break;
 444         case CMIT_FMT_EMAIL:
 445                 ret += sprintf(buf + ret, "Date: %s\n",
 446                                show_rfc2822_date(time, tz));
 447                 break;
 448         case CMIT_FMT_FULLER:
 449                 ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 450                 break;
 451         default:
 452                 /* notin' */
 453                 break;
 454         }
 455         return ret;
 456 }
 457
 458 static int is_empty_line(const char *line, int *len_p)
 459 {
 460         int len = *len_p;
 461         while (len && isspace(line[len-1]))
 462                 len--;
 463         *len_p = len;
 464         return !len;
 465 }
 466
 467 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 468 {
 469         struct commit_list *parent = commit->parents;
 470         int offset;
 471
 472         if ((fmt == CMIT_FMT_ONELINE) || (fmt == CMIT_FMT_EMAIL) ||
 473             !parent || !parent->next)
 474                 return 0;
 475
 476         offset = sprintf(buf, "Merge:");
 477
 478         while (parent) {
 479                 struct commit *p = parent->item;
 480                 const char *hex = abbrev
 481                         ? find_unique_abbrev(p->object.sha1, abbrev)
 482                         : sha1_to_hex(p->object.sha1);
 483                 char *dots = (abbrev && strlen(hex) != 40) ? "..." : "";
 484                 parent = parent->next;
 485
 486                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 487         }
 488         buf[offset++] = '\n';
 489         return offset;
 490 }
 491
 492 unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit, unsigned long len, char *buf, unsigned long space, int abbrev)
 493 {
 494         int hdr = 1, body = 0;
 495         unsigned long offset = 0;
 496         int indent = 4;
 497         int parents_shown = 0;
 498         const char *msg = commit->buffer;
 499         const char *subject = NULL;
 500
 501         if (fmt == CMIT_FMT_EMAIL)
 502                 subject = "Subject: [PATCH] ";
 503         if (fmt == CMIT_FMT_ONELINE || fmt == CMIT_FMT_EMAIL)
 504                 indent = 0;
 505
 506         for (;;) {
 507                 const char *line = msg;
 508                 int linelen = get_one_line(msg, len);
 509
 510                 if (!linelen)
 511                         break;
 512
 513                 /*
 514                  * We want some slop for indentation and a possible
 515                  * final "...". Thus the "+ 20".
 516                  */
 517                 if (offset + linelen + 20 > space) {
 518                         memcpy(buf + offset, "    ...\n", 8);
 519                         offset += 8;
 520                         break;
 521                 }
 522
 523                 msg += linelen;
 524                 len -= linelen;
 525                 if (hdr) {
 526                         if (linelen == 1) {
 527                                 hdr = 0;
 528                                 if ((fmt != CMIT_FMT_ONELINE) && !subject)
 529                                         buf[offset++] = '\n';
 530                                 continue;
 531                         }
 532                         if (fmt == CMIT_FMT_RAW) {
 533                                 memcpy(buf + offset, line, linelen);
 534                                 offset += linelen;
 535                                 continue;
 536                         }
 537                         if (!memcmp(line, "parent ", 7)) {
 538                                 if (linelen != 48)
 539                                         die("bad parent line in commit");
 540                                 continue;
 541                         }
 542
 543                         if (!parents_shown) {
 544                                 offset += add_merge_info(fmt, buf + offset,
 545                                                          commit, abbrev);
 546                                 parents_shown = 1;
 547                                 continue;
 548                         }
 549                         /*
 550                          * MEDIUM == DEFAULT shows only author with dates.
 551                          * FULL shows both authors but not dates.
 552                          * FULLER shows both authors and dates.
 553                          */
 554                         if (!memcmp(line, "author ", 7))
 555                                 offset += add_user_info("Author", fmt,
 556                                                         buf + offset,
 557                                                         line + 7);
 558                         if (!memcmp(line, "committer ", 10) &&
 559                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 560                                 offset += add_user_info("Commit", fmt,
 561                                                         buf + offset,
 562                                                         line + 10);
 563                         continue;
 564                 }
 565
 566                 if (is_empty_line(line, &linelen)) {
 567                         if (!body)
 568                                 continue;
 569                         if (subject)
 570                                 continue;
 571                         if (fmt == CMIT_FMT_SHORT)
 572                                 break;
 573                 } else {
 574                         body = 1;
 575                 }
 576
 577                 if (subject) {
 578                         int slen = strlen(subject);
 579                         memcpy(buf + offset, subject, slen);
 580                         offset += slen;
 581                 }
 582                 memset(buf + offset, ' ', indent);
 583                 memcpy(buf + offset + indent, line, linelen);
 584                 offset += linelen + indent;
 585                 buf[offset++] = '\n';
 586                 if (fmt == CMIT_FMT_ONELINE)
 587                         break;
 588                 subject = NULL;
 589         }
 590         while (offset && isspace(buf[offset-1]))
 591                 offset--;
 592         /* Make sure there is an EOLN for the non-oneline case */
 593         if (fmt != CMIT_FMT_ONELINE)
 594                 buf[offset++] = '\n';
 595         buf[offset] = '\0';
 596         return offset;
 597 }
 598
 599 struct commit *pop_commit(struct commit_list **stack)
 600 {
 601         struct commit_list *top = *stack;
 602         struct commit *item = top ? top->item : NULL;
 603
 604         if (top) {
 605                 *stack = top->next;
 606                 free(top);
 607         }
 608         return item;
 609 }
 610
 611 int count_parents(struct commit * commit)
 612 {
 613         int count = 0;
 614         struct commit_list * parents = commit->parents;
 615         for (count=0;parents; parents=parents->next,count++)
 616           ;
 617         return count;
 618 }
 619
 620 void topo_sort_default_setter(struct commit *c, void *data)
 621 {
 622         c->object.util = data;
 623 }
 624
 625 void *topo_sort_default_getter(struct commit *c)
 626 {
 627         return c->object.util;
 628 }
 629
 630 /*
 631  * Performs an in-place topological sort on the list supplied.
 632  */
 633 void sort_in_topological_order(struct commit_list ** list, int lifo)
 634 {
 635         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 636                                      topo_sort_default_getter);
 637 }
 638
 639 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 640                                   topo_sort_set_fn_t setter,
 641                                   topo_sort_get_fn_t getter)
 642 {
 643         struct commit_list * next = *list;
 644         struct commit_list * work = NULL, **insert;
 645         struct commit_list ** pptr = list;
 646         struct sort_node * nodes;
 647         struct sort_node * next_nodes;
 648         int count = 0;
 649
 650         /* determine the size of the list */
 651         while (next) {
 652                 next = next->next;
 653                 count++;
 654         }
 655
 656         if (!count)
 657                 return;
 658         /* allocate an array to help sort the list */
 659         nodes = xcalloc(count, sizeof(*nodes));
 660         /* link the list to the array */
 661         next_nodes = nodes;
 662         next=*list;
 663         while (next) {
 664                 next_nodes->list_item = next;
 665                 setter(next->item, next_nodes);
 666                 next_nodes++;
 667                 next = next->next;
 668         }
 669         /* update the indegree */
 670         next=*list;
 671         while (next) {
 672                 struct commit_list * parents = next->item->parents;
 673                 while (parents) {
 674                         struct commit * parent=parents->item;
 675                         struct sort_node * pn = (struct sort_node *) getter(parent);
 676
 677                         if (pn)
 678                                 pn->indegree++;
 679                         parents=parents->next;
 680                 }
 681                 next=next->next;
 682         }
 683         /*
 684          * find the tips
 685          *
 686          * tips are nodes not reachable from any other node in the list
 687          *
 688          * the tips serve as a starting set for the work queue.
 689          */
 690         next=*list;
 691         insert = &work;
 692         while (next) {
 693                 struct sort_node * node = (struct sort_node *) getter(next->item);
 694
 695                 if (node->indegree == 0) {
 696                         insert = &commit_list_insert(next->item, insert)->next;
 697                 }
 698                 next=next->next;
 699         }
 700
 701         /* process the list in topological order */
 702         if (!lifo)
 703                 sort_by_date(&work);
 704         while (work) {
 705                 struct commit * work_item = pop_commit(&work);
 706                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
 707                 struct commit_list * parents = work_item->parents;
 708
 709                 while (parents) {
 710                         struct commit * parent=parents->item;
 711                         struct sort_node * pn = (struct sort_node *) getter(parent);
 712
 713                         if (pn) {
 714                                 /*
 715                                  * parents are only enqueued for emission
 716                                  * when all their children have been emitted thereby
 717                                  * guaranteeing topological order.
 718                                  */
 719                                 pn->indegree--;
 720                                 if (!pn->indegree) {
 721                                         if (!lifo)
 722                                                 insert_by_date(parent, &work);
 723                                         else
 724                                                 commit_list_insert(parent, &work);
 725                                 }
 726                         }
 727                         parents=parents->next;
 728                 }
 729                 /*
 730                  * work_item is a commit all of whose children
 731                  * have already been emitted. we can emit it now.
 732                  */
 733                 *pptr = work_node->list_item;
 734                 pptr = &(*pptr)->next;
 735                 *pptr = NULL;
 736                 setter(work_item, NULL);
 737         }
 738         free(nodes);
 739 }