commit.c

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