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
 208         if (item->object.parsed)
 209                 return 0;
 210         item->object.parsed = 1;
 211         if (memcmp(bufptr, "tree ", 5))
 212                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 213         if (get_sha1_hex(bufptr + 5, parent) < 0)
 214                 return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 215         item->tree = lookup_tree(parent);
 216         if (item->tree)
 217                 add_ref(&item->object, &item->tree->object);
 218         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 219         pptr = &item->parents;
 220
 221         graft = lookup_commit_graft(item->object.sha1);
 222         while (!memcmp(bufptr, "parent ", 7)) {
 223                 struct commit *new_parent;
 224
 225                 if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 226                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 227                 bufptr += 48;
 228                 if (graft)
 229                         continue;
 230                 new_parent = lookup_commit(parent);
 231                 if (new_parent) {
 232                         pptr = &commit_list_insert(new_parent, pptr)->next;
 233                         add_ref(&item->object, &new_parent->object);
 234                 }
 235         }
 236         if (graft) {
 237                 int i;
 238                 struct commit *new_parent;
 239                 for (i = 0; i < graft->nr_parent; i++) {
 240                         new_parent = lookup_commit(graft->parent[i]);
 241                         if (!new_parent)
 242                                 continue;
 243                         pptr = &commit_list_insert(new_parent, pptr)->next;
 244                         add_ref(&item->object, &new_parent->object);
 245                 }
 246         }
 247         item->date = parse_commit_date(bufptr);
 248         return 0;
 249 }
 250
 251 int parse_commit(struct commit *item)
 252 {
 253         char type[20];
 254         void *buffer;
 255         unsigned long size;
 256         int ret;
 257
 258         if (item->object.parsed)
 259                 return 0;
 260         buffer = read_sha1_file(item->object.sha1, type, &size);
 261         if (!buffer)
 262                 return error("Could not read %s",
 263                              sha1_to_hex(item->object.sha1));
 264         if (strcmp(type, commit_type)) {
 265                 free(buffer);
 266                 return error("Object %s not a commit",
 267                              sha1_to_hex(item->object.sha1));
 268         }
 269         ret = parse_commit_buffer(item, buffer, size);
 270         if (save_commit_buffer && !ret) {
 271                 item->buffer = buffer;
 272                 return 0;
 273         }
 274         free(buffer);
 275         return ret;
 276 }
 277
 278 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 279 {
 280         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 281         new_list->item = item;
 282         new_list->next = *list_p;
 283         *list_p = new_list;
 284         return new_list;
 285 }
 286
 287 void free_commit_list(struct commit_list *list)
 288 {
 289         while (list) {
 290                 struct commit_list *temp = list;
 291                 list = temp->next;
 292                 free(temp);
 293         }
 294 }
 295
 296 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 297 {
 298         struct commit_list **pp = list;
 299         struct commit_list *p;
 300         while ((p = *pp) != NULL) {
 301                 if (p->item->date < item->date) {
 302                         break;
 303                 }
 304                 pp = &p->next;
 305         }
 306         return commit_list_insert(item, pp);
 307 }
 308
 309
 310 void sort_by_date(struct commit_list **list)
 311 {
 312         struct commit_list *ret = NULL;
 313         while (*list) {
 314                 insert_by_date((*list)->item, &ret);
 315                 *list = (*list)->next;
 316         }
 317         *list = ret;
 318 }
 319
 320 struct commit *pop_most_recent_commit(struct commit_list **list,
 321                                       unsigned int mark)
 322 {
 323         struct commit *ret = (*list)->item;
 324         struct commit_list *parents = ret->parents;
 325         struct commit_list *old = *list;
 326
 327         *list = (*list)->next;
 328         free(old);
 329
 330         while (parents) {
 331                 struct commit *commit = parents->item;
 332                 parse_commit(commit);
 333                 if (!(commit->object.flags & mark)) {
 334                         commit->object.flags |= mark;
 335                         insert_by_date(commit, list);
 336                 }
 337                 parents = parents->next;
 338         }
 339         return ret;
 340 }
 341
 342 /*
 343  * Generic support for pretty-printing the header
 344  */
 345 static int get_one_line(const char *msg, unsigned long len)
 346 {
 347         int ret = 0;
 348
 349         while (len--) {
 350                 char c = *msg++;
 351                 ret++;
 352                 if (c == '\n')
 353                         break;
 354                 if (!c)
 355                         return 0;
 356         }
 357         return ret;
 358 }
 359
 360 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 361 {
 362         char *date;
 363         int namelen;
 364         unsigned long time;
 365         int tz, ret;
 366         const char *filler = "    ";
 367
 368         if (fmt == CMIT_FMT_ONELINE)
 369                 return 0;
 370         date = strchr(line, '>');
 371         if (!date)
 372                 return 0;
 373         namelen = ++date - line;
 374         time = strtoul(date, &date, 10);
 375         tz = strtol(date, NULL, 10);
 376
 377         ret = sprintf(buf, "%s: %.*s%.*s\n", what,
 378                       (fmt == CMIT_FMT_FULLER) ? 4 : 0,
 379                       filler, namelen, line);
 380         switch (fmt) {
 381         case CMIT_FMT_MEDIUM:
 382                 ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 383                 break;
 384         case CMIT_FMT_FULLER:
 385                 ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
 386                 break;
 387         default:
 388                 /* notin' */
 389                 break;
 390         }
 391         return ret;
 392 }
 393
 394 static int is_empty_line(const char *line, int len)
 395 {
 396         while (len && isspace(line[len-1]))
 397                 len--;
 398         return !len;
 399 }
 400
 401 static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 402 {
 403         int offset = 0;
 404
 405         if (fmt == CMIT_FMT_ONELINE)
 406                 return offset;
 407         switch (parents) {
 408         case 1:
 409                 break;
 410         case 2:
 411                 /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 412                 offset = sprintf(buf, "Merge: %.40s\n", line-41);
 413                 /* Fallthrough */
 414         default:
 415                 /* Replace the previous '\n' with a space */
 416                 buf[offset-1] = ' ';
 417                 offset += sprintf(buf + offset, "%.40s\n", line+7);
 418         }
 419         return offset;
 420 }
 421
 422 unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 423 {
 424         int hdr = 1, body = 0;
 425         unsigned long offset = 0;
 426         int parents = 0;
 427         int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
 428
 429         for (;;) {
 430                 const char *line = msg;
 431                 int linelen = get_one_line(msg, len);
 432
 433                 if (!linelen)
 434                         break;
 435
 436                 /*
 437                  * We want some slop for indentation and a possible
 438                  * final "...". Thus the "+ 20".
 439                  */
 440                 if (offset + linelen + 20 > space) {
 441                         memcpy(buf + offset, "    ...\n", 8);
 442                         offset += 8;
 443                         break;
 444                 }
 445
 446                 msg += linelen;
 447                 len -= linelen;
 448                 if (hdr) {
 449                         if (linelen == 1) {
 450                                 hdr = 0;
 451                                 if (fmt != CMIT_FMT_ONELINE)
 452                                         buf[offset++] = '\n';
 453                                 continue;
 454                         }
 455                         if (fmt == CMIT_FMT_RAW) {
 456                                 memcpy(buf + offset, line, linelen);
 457                                 offset += linelen;
 458                                 continue;
 459                         }
 460                         if (!memcmp(line, "parent ", 7)) {
 461                                 if (linelen != 48)
 462                                         die("bad parent line in commit");
 463                                 offset += add_parent_info(fmt, buf + offset, line, ++parents);
 464                         }
 465
 466                         /*
 467                          * MEDIUM == DEFAULT shows only author with dates.
 468                          * FULL shows both authors but not dates.
 469                          * FULLER shows both authors and dates.
 470                          */
 471                         if (!memcmp(line, "author ", 7))
 472                                 offset += add_user_info("Author", fmt,
 473                                                         buf + offset,
 474                                                         line + 7);
 475                         if (!memcmp(line, "committer ", 10) &&
 476                             (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
 477                                 offset += add_user_info("Commit", fmt,
 478                                                         buf + offset,
 479                                                         line + 10);
 480                         continue;
 481                 }
 482
 483                 if (is_empty_line(line, linelen)) {
 484                         if (!body)
 485                                 continue;
 486                         if (fmt == CMIT_FMT_SHORT)
 487                                 break;
 488                 } else {
 489                         body = 1;
 490                 }
 491
 492                 memset(buf + offset, ' ', indent);
 493                 memcpy(buf + offset + indent, line, linelen);
 494                 offset += linelen + indent;
 495                 if (fmt == CMIT_FMT_ONELINE)
 496                         break;
 497         }
 498         if (fmt == CMIT_FMT_ONELINE) {
 499                 /* We do not want the terminating newline */
 500                 if (buf[offset - 1] == '\n')
 501                         offset--;
 502         }
 503         else {
 504                 /* Make sure there is an EOLN */
 505                 if (buf[offset - 1] != '\n')
 506                         buf[offset++] = '\n';
 507         }
 508         buf[offset] = '\0';
 509         return offset;
 510 }
 511
 512 struct commit *pop_commit(struct commit_list **stack)
 513 {
 514         struct commit_list *top = *stack;
 515         struct commit *item = top ? top->item : NULL;
 516
 517         if (top) {
 518                 *stack = top->next;
 519                 free(top);
 520         }
 521         return item;
 522 }
 523
 524 int count_parents(struct commit * commit)
 525 {
 526         int count = 0;
 527         struct commit_list * parents = commit->parents;
 528         for (count=0;parents; parents=parents->next,count++)
 529           ;
 530         return count;
 531 }
 532
 533 /*
 534  * Performs an in-place topological sort on the list supplied.
 535  */
 536 void sort_in_topological_order(struct commit_list ** list)
 537 {
 538         struct commit_list * next = *list;
 539         struct commit_list * work = NULL, **insert;
 540         struct commit_list ** pptr = list;
 541         struct sort_node * nodes;
 542         struct sort_node * next_nodes;
 543         int count = 0;
 544
 545         /* determine the size of the list */
 546         while (next) {
 547                 next = next->next;
 548                 count++;
 549         }
 550         /* allocate an array to help sort the list */
 551         nodes = xcalloc(count, sizeof(*nodes));
 552         /* link the list to the array */
 553         next_nodes = nodes;
 554         next=*list;
 555         while (next) {
 556                 next_nodes->list_item = next;
 557                 next->item->object.util = next_nodes;
 558                 next_nodes++;
 559                 next = next->next;
 560         }
 561         /* update the indegree */
 562         next=*list;
 563         while (next) {
 564                 struct commit_list * parents = next->item->parents;
 565                 while (parents) {
 566                         struct commit * parent=parents->item;
 567                         struct sort_node * pn = (struct sort_node *)parent->object.util;
 568
 569                         if (pn)
 570                                 pn->indegree++;
 571                         parents=parents->next;
 572                 }
 573                 next=next->next;
 574         }
 575         /*
 576          * find the tips
 577          *
 578          * tips are nodes not reachable from any other node in the list
 579          *
 580          * the tips serve as a starting set for the work queue.
 581          */
 582         next=*list;
 583         insert = &work;
 584         while (next) {
 585                 struct sort_node * node = (struct sort_node *)next->item->object.util;
 586
 587                 if (node->indegree == 0) {
 588                         insert = &commit_list_insert(next->item, insert)->next;
 589                 }
 590                 next=next->next;
 591         }
 592         /* process the list in topological order */
 593         while (work) {
 594                 struct commit * work_item = pop_commit(&work);
 595                 struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 596                 struct commit_list * parents = work_item->parents;
 597
 598                 while (parents) {
 599                         struct commit * parent=parents->item;
 600                         struct sort_node * pn = (struct sort_node *)parent->object.util;
 601
 602                         if (pn) {
 603                                 /*
 604                                  * parents are only enqueued for emission
 605                                  * when all their children have been emitted thereby
 606                                  * guaranteeing topological order.
 607                                  */
 608                                 pn->indegree--;
 609                                 if (!pn->indegree)
 610                                         commit_list_insert(parent, &work);
 611                         }
 612                         parents=parents->next;
 613                 }
 614                 /*
 615                  * work_item is a commit all of whose children
 616                  * have already been emitted. we can emit it now.
 617                  */
 618                 *pptr = work_node->list_item;
 619                 pptr = &(*pptr)->next;
 620                 *pptr = NULL;
 621                 work_item->object.util = NULL;
 622         }
 623         free(nodes);
 624 }