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 struct cmt_fmt_map {
  26         const char *n;
  27         size_t cmp_len;
  28         enum cmit_fmt v;
  29 } cmt_fmts[] = {
  30         { "raw",        1,      CMIT_FMT_RAW },
  31         { "medium",     1,      CMIT_FMT_MEDIUM },
  32         { "short",      1,      CMIT_FMT_SHORT },
  33         { "full",       5,      CMIT_FMT_FULL },
  34         { "fuller",     5,      CMIT_FMT_FULLER },
  35         { "oneline",    1,      CMIT_FMT_ONELINE },
  36 };
  37
  38 enum cmit_fmt get_commit_format(const char *arg)
  39 {
  40         int i;
  41
  42         if (!arg || !*arg)
  43                 return CMIT_FMT_DEFAULT;
  44         if (*arg == '=')
  45                 arg++;
  46         for (i = 0; i < ARRAY_SIZE(cmt_fmts); i++) {
  47                 if (!strncmp(arg, cmt_fmts[i].n, cmt_fmts[i].cmp_len))
  48                         return cmt_fmts[i].v;
  49         }
  50
  51         die("invalid --pretty format: %s", arg);
  52 }
  53
  54 static struct commit *check_commit(struct object *obj,
  55                                    const unsigned char *sha1,
  56                                    int quiet)
  57 {
  58         if (obj->type != commit_type) {
  59                 if (!quiet)
  60                         error("Object %s is a %s, not a commit",
  61                               sha1_to_hex(sha1), obj->type);
  62                 return NULL;
  63         }
  64         return (struct commit *) obj;
  65 }
  66
  67 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
  68                                               int quiet)
  69 {
  70         struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
  71
  72         if (!obj)
  73                 return NULL;
  74         return check_commit(obj, sha1, quiet);
  75 }
  76
  77 struct commit *lookup_commit_reference(const unsigned char *sha1)
  78 {
  79         return lookup_commit_reference_gently(sha1, 0);
  80 }
  81
  82 struct commit *lookup_commit(const unsigned char *sha1)
  83 {
  84         struct object *obj = lookup_object(sha1);
  85         if (!obj) {
  86                 struct commit *ret = xcalloc(1, sizeof(struct commit));
  87                 created_object(sha1, &ret->object);
  88                 ret->object.type = commit_type;
  89                 return ret;
  90         }
  91         if (!obj->type)
  92                 obj->type = commit_type;
  93         return check_commit(obj, sha1, 0);
  94 }
  95
  96 static unsigned long parse_commit_date(const char *buf)
  97 {
  98         unsigned long date;
  99
 100         if (memcmp(buf, "author", 6))
 101                 return 0;
 102         while (*buf++ != '\n')
 103                 /* nada */;
 104         if (memcmp(buf, "committer", 9))
 105                 return 0;
 106         while (*buf++ != '>')
 107                 /* nada */;
 108         date = strtoul(buf, NULL, 10);
 109         if (date == ULONG_MAX)
 110                 date = 0;
 111         return date;
 112 }
 113
 114 static struct commit_graft **commit_graft;
 115 static int commit_graft_alloc, commit_graft_nr;
 116
 117 static int commit_graft_pos(const unsigned char *sha1)
 118 {
 119         int lo, hi;
 120         lo = 0;
 121         hi = commit_graft_nr;
 122         while (lo < hi) {
 123                 int mi = (lo + hi) / 2;
 124                 struct commit_graft *graft = commit_graft[mi];
 125                 int cmp = memcmp(sha1, graft->sha1, 20);
 126                 if (!cmp)
 127                         return mi;
 128                 if (cmp < 0)
 129                         hi = mi;
 130                 else
 131                         lo = mi + 1;
 132         }
 133         return -lo - 1;
 134 }
 135
 136 int register_commit_graft(struct commit_graft *graft, int ignore_dups)
 137 {
 138         int pos = commit_graft_pos(graft->sha1);
 139
 140         if (0 <= pos) {
 141                 if (ignore_dups)
 142                         free(graft);
 143                 else {
 144                         free(commit_graft[pos]);
 145                         commit_graft[pos] = graft;
 146                 }
 147                 return 1;
 148         }
 149         pos = -pos - 1;
 150         if (commit_graft_alloc <= ++commit_graft_nr) {
 151                 commit_graft_alloc = alloc_nr(commit_graft_alloc);
 152                 commit_graft = xrealloc(commit_graft,
 153                                         sizeof(*commit_graft) *
 154                                         commit_graft_alloc);
 155         }
 156         if (pos < commit_graft_nr)
 157                 memmove(commit_graft + pos + 1,
 158                         commit_graft + pos,
 159                         (commit_graft_nr - pos - 1) *
 160                         sizeof(*commit_graft));
 161         commit_graft[pos] = graft;
 162         return 0;
 163 }
 164
 165 struct commit_graft *read_graft_line(char *buf, int len)
 166 {
 167         /* The format is just "Commit Parent1 Parent2 ...\n" */
 168         int i;
 169         struct commit_graft *graft = NULL;
 170
 171         if (buf[len-1] == '\n')
 172                 buf[--len] = 0;
 173         if (buf[0] == '#' || buf[0] == '\0')
 174                 return NULL;
 175         if ((len + 1) % 41) {
 176         bad_graft_data:
 177                 error("bad graft data: %s", buf);
 178                 free(graft);
 179                 return NULL;
 180         }
 181         i = (len + 1) / 41 - 1;
 182         graft = xmalloc(sizeof(*graft) + 20 * i);
 183         graft->nr_parent = i;
 184         if (get_sha1_hex(buf, graft->sha1))
 185                 goto bad_graft_data;
 186         for (i = 40; i < len; i += 41) {
 187                 if (buf[i] != ' ')
 188                         goto bad_graft_data;
 189                 if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
 190                         goto bad_graft_data;
 191         }
 192         return graft;
 193 }
 194
 195 int read_graft_file(const char *graft_file)
 196 {
 197         FILE *fp = fopen(graft_file, "r");
 198         char buf[1024];
 199         if (!fp)
 200                 return -1;
 201         while (fgets(buf, sizeof(buf), fp)) {
 202                 /* The format is just "Commit Parent1 Parent2 ...\n" */
 203                 int len = strlen(buf);
 204                 struct commit_graft *graft = read_graft_line(buf, len);
 205                 if (!graft)
 206                         continue;
 207                 if (register_commit_graft(graft, 1))
 208                         error("duplicate graft data: %s", buf);
 209         }
 210         fclose(fp);
 211         return 0;
 212 }
 213
 214 static void prepare_commit_graft(void)
 215 {
 216         static int commit_graft_prepared;
 217         char *graft_file;
 218
 219         if (commit_graft_prepared)
 220                 return;
 221         graft_file = get_graft_file();
 222         read_graft_file(graft_file);
 223         commit_graft_prepared = 1;
 224 }
 225
 226 static struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
 227 {
 228         int pos;
 229         prepare_commit_graft();
 230         pos = commit_graft_pos(sha1);
 231         if (pos < 0)
 232                 return NULL;
 233         return commit_graft[pos];
 234 }
 235
 236 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
 237 {
 238         char *bufptr = buffer;
 239         unsigned char parent[20];
 240         struct commit_list **pptr;
 241         struct commit_graft *graft;
 242         unsigned n_refs = 0;
 243
 244         if (item->object.parsed)
 245                 return 0;
 246         item->object.parsed = 1;
 247         if (memcmp(bufptr, "tree ", 5))
 248                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 249         if (get_sha1_hex(bufptr + 5, parent) < 0)
 250                 return error("bad tree pointer in commit %s",
 251                              sha1_to_hex(item->object.sha1));
 252         item->tree = lookup_tree(parent);
 253         if (item->tree)
 254                 n_refs++;
 255         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 256         pptr = &item->parents;
 257
 258         graft = lookup_commit_graft(item->object.sha1);
 259         while (!memcmp(bufptr, "parent ", 7)) {
 260                 struct commit *new_parent;
 261
 262                 if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 263                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 264                 bufptr += 48;
 265                 if (graft)
 266                         continue;
 267                 new_parent = lookup_commit(parent);
 268                 if (new_parent) {
 269                         pptr = &commit_list_insert(new_parent, pptr)->next;
 270                         n_refs++;
 271                 }
 272         }
 273         if (graft) {
 274                 int i;
 275                 struct commit *new_parent;
 276                 for (i = 0; i < graft->nr_parent; i++) {
 277                         new_parent = lookup_commit(graft->parent[i]);
 278                         if (!new_parent)
 279                                 continue;
 280                         pptr = &commit_list_insert(new_parent, pptr)->next;
 281                         n_refs++;
 282                 }
 283         }
 284         item->date = parse_commit_date(bufptr);
 285
 286         if (track_object_refs) {
 287                 unsigned i = 0;
 288                 struct commit_list *p;
 289                 struct object_refs *refs = alloc_object_refs(n_refs);
 290                 if (item->tree)
 291                         refs->ref[i++] = &item->tree->object;
 292                 for (p = item->parents; p; p = p->next)
 293                         refs->ref[i++] = &p->item->object;
 294                 set_object_refs(&item->object, refs);
 295         }
 296
 297         return 0;
 298 }
 299
 300 int parse_commit(struct commit *item)
 301 {
 302         char type[20];
 303         void *buffer;
 304         unsigned long size;
 305         int ret;
 306
 307         if (item->object.parsed)
 308                 return 0;
 309         buffer = read_sha1_file(item->object.sha1, type, &size);
 310         if (!buffer)
 311                 return error("Could not read %s",
 312                              sha1_to_hex(item->object.sha1));
 313         if (strcmp(type, commit_type)) {
 314                 free(buffer);
 315                 return error("Object %s not a commit",
 316                              sha1_to_hex(item->object.sha1));
 317         }
 318         ret = parse_commit_buffer(item, buffer, size);
 319         if (save_commit_buffer && !ret) {
 320                 item->buffer = buffer;
 321                 return 0;
 322         }
 323         free(buffer);
 324         return ret;
 325 }
 326
 327 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 328 {
 329         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 330         new_list->item = item;
 331         new_list->next = *list_p;
 332         *list_p = new_list;
 333         return new_list;
 334 }
 335
 336 void free_commit_list(struct commit_list *list)
 337 {
 338         while (list) {
 339                 struct commit_list *temp = list;
 340                 list = temp->next;
 341                 free(temp);
 342         }
 343 }
 344
 345 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 346 {
 347         struct commit_list **pp = list;
 348         struct commit_list *p;
 349         while ((p = *pp) != NULL) {
 350                 if (p->item->date < item->date) {
 351                         break;
 352                 }
 353                 pp = &p->next;
 354         }
 355         return commit_list_insert(item, pp);
 356 }
 357
 358
 359 void sort_by_date(struct commit_list **list)
 360 {
 361         struct commit_list *ret = NULL;
 362         while (*list) {
 363                 insert_by_date((*list)->item, &ret);
 364                 *list = (*list)->next;
 365         }
 366         *list = ret;
 367 }
 368
 369 struct commit *pop_most_recent_commit(struct commit_list **list,
 370                                       unsigned int mark)
 371 {
 372         struct commit *ret = (*list)->item;
 373         struct commit_list *parents = ret->parents;
 374         struct commit_list *old = *list;
 375
 376         *list = (*list)->next;
 377         free(old);
 378
 379         while (parents) {
 380                 struct commit *commit = parents->item;
 381                 parse_commit(commit);
 382                 if (!(commit->object.flags & mark)) {
 383                         commit->object.flags |= mark;
 384                         insert_by_date(commit, list);
 385                 }
 386                 parents = parents->next;
 387         }
 388         return ret;
 389 }
 390
 391 void clear_commit_marks(struct commit *commit, unsigned int mark)
 392 {
 393         struct commit_list *parents;
 394
 395         parents = commit->parents;
 396         commit->object.flags &= ~mark;
 397         while (parents) {
 398                 struct commit *parent = parents->item;
 399                 if (parent && parent->object.parsed &&
 400                     (parent->object.flags & mark))
 401                         clear_commit_marks(parent, mark);
 402                 parents = parents->next;
 403         }
 404 }
 405
 406 /*
 407  * Generic support for pretty-printing the header
 408  */
 409 static int get_one_line(const char *msg, unsigned long len)
 410 {
 411         int ret = 0;
 412
 413         while (len--) {
 414                 char c = *msg++;
 415                 if (!c)
 416                         break;
 417                 ret++;
 418                 if (c == '\n')
 419                         break;
 420         }
 421         return ret;
 422 }
 423
 424 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 425 {
 426         char *date;
 427         int namelen;
 428         unsigned long time;
 429         int tz, ret;
 430         const char *filler = "    ";
 431
 432         if (fmt == CMIT_FMT_ONELINE)
 433                 return 0;
 434         date = strchr(line, '>');
 435         if (!date)
 436                 return 0;
 437         namelen = ++date - line;
 438         time = strtoul(date, &date, 10);
 439         tz = strtol(date, NULL, 10);
 440
 441         ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 442                       (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 443                       filler, namelen, line);
 444         switch (fmt) {
 445         case CMIT_FMT_MEDIUM:
 446                 ret += sprintf(buf + ret, "Date:   %s\n", show_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)
 459 {
 460         while (len && isspace(line[len-1]))
 461                 len--;
 462         return !len;
 463 }
 464
 465 static int add_merge_info(enum cmit_fmt fmt, char *buf, const struct commit *commit, int abbrev)
 466 {
 467         struct commit_list *parent = commit->parents;
 468         int offset;
 469
 470         if ((fmt == CMIT_FMT_ONELINE) || !parent || !parent->next)
 471                 return 0;
 472
 473         offset = sprintf(buf, "Merge:");
 474
 475         while (parent) {
 476                 struct commit *p = parent->item;
 477                 const char *hex = abbrev
 478                         ? find_unique_abbrev(p->object.sha1, abbrev)
 479                         : sha1_to_hex(p->object.sha1);
 480                 char *dots = (abbrev && strlen(hex) != 40) ? "..." : "";
 481                 parent = parent->next;
 482
 483                 offset += sprintf(buf + offset, " %s%s", hex, dots);
 484         }
 485         buf[offset++] = '\n';
 486         return offset;
 487 }
 488
 489 unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit, unsigned long len, char *buf, unsigned long space, int abbrev)
 490 {
 491         int hdr = 1, body = 0;
 492         unsigned long offset = 0;
 493         int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 494         int parents_shown = 0;
 495         const char *msg = commit->buffer;
 496
 497         for (;;) {
 498                 const char *line = msg;
 499                 int linelen = get_one_line(msg, len);
 500
 501                 if (!linelen)
 502                         break;
 503
 504                 /*
 505                  * We want some slop for indentation and a possible
 506                  * final "...". Thus the "+ 20".
 507                  */
 508                 if (offset + linelen + 20 > space) {
 509                         memcpy(buf + offset, "    ...\n", 8);
 510                         offset += 8;
 511                         break;
 512                 }
 513
 514                 msg += linelen;
 515                 len -= linelen;
 516                 if (hdr) {
 517                         if (linelen == 1) {
 518                                 hdr = 0;
 519                                 if (fmt != CMIT_FMT_ONELINE)
 520                                         buf[offset++] = '\n';
 521                                 continue;
 522                         }
 523                         if (fmt == CMIT_FMT_RAW) {
 524                                 memcpy(buf + offset, line, linelen);
 525                                 offset += linelen;
 526                                 continue;
 527                         }
 528                         if (!memcmp(line, "parent ", 7)) {
 529                                 if (linelen != 48)
 530                                         die("bad parent line in commit");
 531                                 continue;
 532                         }
 533
 534                         if (!parents_shown) {
 535                                 offset += add_merge_info(fmt, buf + offset,
 536                                                          commit, abbrev);
 537                                 parents_shown = 1;
 538                                 continue;
 539                         }
 540                         /*
 541                          * MEDIUM == DEFAULT shows only author with dates.
 542                          * FULL shows both authors but not dates.
 543                          * FULLER shows both authors and dates.
 544                          */
 545                         if (!memcmp(line, "author ", 7))
 546                                 offset += add_user_info("Author", fmt,
 547                                                         buf + offset,
 548                                                         line + 7);
 549                         if (!memcmp(line, "committer ", 10) &&
 550                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 551                                 offset += add_user_info("Commit", fmt,
 552                                                         buf + offset,
 553                                                         line + 10);
 554                         continue;
 555                 }
 556
 557                 if (is_empty_line(line, linelen)) {
 558                         if (!body)
 559                                 continue;
 560                         if (fmt == CMIT_FMT_SHORT)
 561                                 break;
 562                 } else {
 563                         body = 1;
 564                 }
 565
 566                 memset(buf + offset, ' ', indent);
 567                 memcpy(buf + offset + indent, line, linelen);
 568                 offset += linelen + indent;
 569                 if (fmt == CMIT_FMT_ONELINE)
 570                         break;
 571         }
 572         while (offset && isspace(buf[offset-1]))
 573                 offset--;
 574         /* Make sure there is an EOLN for the non-oneline case */
 575         if (fmt != CMIT_FMT_ONELINE)
 576                 buf[offset++] = '\n';
 577         buf[offset] = '\0';
 578         return offset;
 579 }
 580
 581 struct commit *pop_commit(struct commit_list **stack)
 582 {
 583         struct commit_list *top = *stack;
 584         struct commit *item = top ? top->item : NULL;
 585
 586         if (top) {
 587                 *stack = top->next;
 588                 free(top);
 589         }
 590         return item;
 591 }
 592
 593 int count_parents(struct commit * commit)
 594 {
 595         int count = 0;
 596         struct commit_list * parents = commit->parents;
 597         for (count=0;parents; parents=parents->next,count++)
 598           ;
 599         return count;
 600 }
 601
 602 void topo_sort_default_setter(struct commit *c, void *data)
 603 {
 604         c->object.util = data;
 605 }
 606
 607 void *topo_sort_default_getter(struct commit *c)
 608 {
 609         return c->object.util;
 610 }
 611
 612 /*
 613  * Performs an in-place topological sort on the list supplied.
 614  */
 615 void sort_in_topological_order(struct commit_list ** list, int lifo)
 616 {
 617         sort_in_topological_order_fn(list, lifo, topo_sort_default_setter,
 618                                      topo_sort_default_getter);
 619 }
 620
 621 void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
 622                                   topo_sort_set_fn_t setter,
 623                                   topo_sort_get_fn_t getter)
 624 {
 625         struct commit_list * next = *list;
 626         struct commit_list * work = NULL, **insert;
 627         struct commit_list ** pptr = list;
 628         struct sort_node * nodes;
 629         struct sort_node * next_nodes;
 630         int count = 0;
 631
 632         /* determine the size of the list */
 633         while (next) {
 634                 next = next->next;
 635                 count++;
 636         }
 637
 638         if (!count)
 639                 return;
 640         /* allocate an array to help sort the list */
 641         nodes = xcalloc(count, sizeof(*nodes));
 642         /* link the list to the array */
 643         next_nodes = nodes;
 644         next=*list;
 645         while (next) {
 646                 next_nodes->list_item = next;
 647                 setter(next->item, next_nodes);
 648                 next_nodes++;
 649                 next = next->next;
 650         }
 651         /* update the indegree */
 652         next=*list;
 653         while (next) {
 654                 struct commit_list * parents = next->item->parents;
 655                 while (parents) {
 656                         struct commit * parent=parents->item;
 657                         struct sort_node * pn = (struct sort_node *) getter(parent);
 658
 659                         if (pn)
 660                                 pn->indegree++;
 661                         parents=parents->next;
 662                 }
 663                 next=next->next;
 664         }
 665         /*
 666          * find the tips
 667          *
 668          * tips are nodes not reachable from any other node in the list
 669          *
 670          * the tips serve as a starting set for the work queue.
 671          */
 672         next=*list;
 673         insert = &work;
 674         while (next) {
 675                 struct sort_node * node = (struct sort_node *) getter(next->item);
 676
 677                 if (node->indegree == 0) {
 678                         insert = &commit_list_insert(next->item, insert)->next;
 679                 }
 680                 next=next->next;
 681         }
 682
 683         /* process the list in topological order */
 684         if (!lifo)
 685                 sort_by_date(&work);
 686         while (work) {
 687                 struct commit * work_item = pop_commit(&work);
 688                 struct sort_node * work_node = (struct sort_node *) getter(work_item);
 689                 struct commit_list * parents = work_item->parents;
 690
 691                 while (parents) {
 692                         struct commit * parent=parents->item;
 693                         struct sort_node * pn = (struct sort_node *) getter(parent);
 694
 695                         if (pn) {
 696                                 /*
 697                                  * parents are only enqueued for emission
 698                                  * when all their children have been emitted thereby
 699                                  * guaranteeing topological order.
 700                                  */
 701                                 pn->indegree--;
 702                                 if (!pn->indegree) {
 703                                         if (!lifo)
 704                                                 insert_by_date(parent, &work);
 705                                         else
 706                                                 commit_list_insert(parent, &work);
 707                                 }
 708                         }
 709                         parents=parents->next;
 710                 }
 711                 /*
 712                  * work_item is a commit all of whose children
 713                  * have already been emitted. we can emit it now.
 714                  */
 715                 *pptr = work_node->list_item;
 716                 pptr = &(*pptr)->next;
 717                 *pptr = NULL;
 718                 setter(work_item, NULL);
 719         }
 720         free(nodes);
 721 }