commit.c

   1 #include <ctype.h>
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "cache.h"
   5
   6 struct sort_node
   7 {
   8         /*
   9          * the number of children of the associated commit
  10          * that also occur in the list being sorted.
  11          */
  12         unsigned int indegree;
  13
  14         /*
  15          * reference to original list item that we will re-use
  16          * on output.
  17          */
  18         struct commit_list * list_item;
  19
  20 };
  21
  22 const char *commit_type = "commit";
  23
  24 enum cmit_fmt get_commit_format(const char *arg)
  25 {
  26         if (!*arg)
  27                 return CMIT_FMT_DEFAULT;
  28         if (!strcmp(arg, "=raw"))
  29                 return CMIT_FMT_RAW;
  30         if (!strcmp(arg, "=medium"))
  31                 return CMIT_FMT_MEDIUM;
  32         if (!strcmp(arg, "=short"))
  33                 return CMIT_FMT_SHORT;
  34         if (!strcmp(arg, "=full"))
  35                 return CMIT_FMT_FULL;
  36         die("invalid --pretty format");
  37 }
  38
  39 static struct commit *check_commit(struct object *obj, const unsigned char *sha1)
  40 {
  41         if (obj->type != commit_type) {
  42                 error("Object %s is a %s, not a commit",
  43                       sha1_to_hex(sha1), obj->type);
  44                 return NULL;
  45         }
  46         return (struct commit *) obj;
  47 }
  48
  49 struct commit *lookup_commit_reference(const unsigned char *sha1)
  50 {
  51         struct object *obj = parse_object(sha1);
  52
  53         if (!obj)
  54                 return NULL;
  55         while (obj->type == tag_type)
  56                 obj = parse_object(((struct tag *)obj)->tagged->sha1);
  57
  58         return check_commit(obj, sha1);
  59 }
  60
  61 struct commit *lookup_commit(const unsigned char *sha1)
  62 {
  63         struct object *obj = lookup_object(sha1);
  64         if (!obj) {
  65                 struct commit *ret = xmalloc(sizeof(struct commit));
  66                 memset(ret, 0, sizeof(struct commit));
  67                 created_object(sha1, &ret->object);
  68                 ret->object.type = commit_type;
  69                 return ret;
  70         }
  71         if (!obj->type)
  72                 obj->type = commit_type;
  73         return check_commit(obj, sha1);
  74 }
  75
  76 static unsigned long parse_commit_date(const char *buf)
  77 {
  78         unsigned long date;
  79
  80         if (memcmp(buf, "author", 6))
  81                 return 0;
  82         while (*buf++ != '\n')
  83                 /* nada */;
  84         if (memcmp(buf, "committer", 9))
  85                 return 0;
  86         while (*buf++ != '>')
  87                 /* nada */;
  88         date = strtoul(buf, NULL, 10);
  89         if (date == ULONG_MAX)
  90                 date = 0;
  91         return date;
  92 }
  93
  94 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
  95 {
  96         char *bufptr = buffer;
  97         unsigned char parent[20];
  98         struct commit_list **pptr;
  99
 100         if (item->object.parsed)
 101                 return 0;
 102         item->object.parsed = 1;
 103         if (memcmp(bufptr, "tree ", 5))
 104                 return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
 105         if (get_sha1_hex(bufptr + 5, parent) < 0)
 106                 return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
 107         item->tree = lookup_tree(parent);
 108         if (item->tree)
 109                 add_ref(&item->object, &item->tree->object);
 110         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
 111         pptr = &item->parents;
 112         while (!memcmp(bufptr, "parent ", 7)) {
 113                 struct commit *new_parent;
 114
 115                 if (get_sha1_hex(bufptr + 7, parent) || bufptr[47] != '\n')
 116                         return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
 117                 new_parent = lookup_commit(parent);
 118                 if (new_parent) {
 119                         pptr = &commit_list_insert(new_parent, pptr)->next;
 120                         add_ref(&item->object, &new_parent->object);
 121                 }
 122                 bufptr += 48;
 123         }
 124         item->date = parse_commit_date(bufptr);
 125         return 0;
 126 }
 127
 128 int parse_commit(struct commit *item)
 129 {
 130         char type[20];
 131         void *buffer;
 132         unsigned long size;
 133         int ret;
 134
 135         if (item->object.parsed)
 136                 return 0;
 137         buffer = read_sha1_file(item->object.sha1, type, &size);
 138         if (!buffer)
 139                 return error("Could not read %s",
 140                              sha1_to_hex(item->object.sha1));
 141         if (strcmp(type, commit_type)) {
 142                 free(buffer);
 143                 return error("Object %s not a commit",
 144                              sha1_to_hex(item->object.sha1));
 145         }
 146         ret = parse_commit_buffer(item, buffer, size);
 147         if (!ret) {
 148                 item->buffer = buffer;
 149                 return 0;
 150         }
 151         free(buffer);
 152         return ret;
 153 }
 154
 155 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
 156 {
 157         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
 158         new_list->item = item;
 159         new_list->next = *list_p;
 160         *list_p = new_list;
 161         return new_list;
 162 }
 163
 164 void free_commit_list(struct commit_list *list)
 165 {
 166         while (list) {
 167                 struct commit_list *temp = list;
 168                 list = temp->next;
 169                 free(temp);
 170         }
 171 }
 172
 173 struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 174 {
 175         struct commit_list **pp = list;
 176         struct commit_list *p;
 177         while ((p = *pp) != NULL) {
 178                 if (p->item->date < item->date) {
 179                         break;
 180                 }
 181                 pp = &p->next;
 182         }
 183         return commit_list_insert(item, pp);
 184 }
 185
 186
 187 void sort_by_date(struct commit_list **list)
 188 {
 189         struct commit_list *ret = NULL;
 190         while (*list) {
 191                 insert_by_date((*list)->item, &ret);
 192                 *list = (*list)->next;
 193         }
 194         *list = ret;
 195 }
 196
 197 struct commit *pop_most_recent_commit(struct commit_list **list,
 198                                       unsigned int mark)
 199 {
 200         struct commit *ret = (*list)->item;
 201         struct commit_list *parents = ret->parents;
 202         struct commit_list *old = *list;
 203
 204         *list = (*list)->next;
 205         free(old);
 206
 207         while (parents) {
 208                 struct commit *commit = parents->item;
 209                 parse_commit(commit);
 210                 if (!(commit->object.flags & mark)) {
 211                         commit->object.flags |= mark;
 212                         insert_by_date(commit, list);
 213                 }
 214                 parents = parents->next;
 215         }
 216         return ret;
 217 }
 218
 219 /*
 220  * Generic support for pretty-printing the header
 221  */
 222 static int get_one_line(const char *msg, unsigned long len)
 223 {
 224         int ret = 0;
 225
 226         while (len--) {
 227                 char c = *msg++;
 228                 ret++;
 229                 if (c == '\n')
 230                         break;
 231                 if (!c)
 232                         return 0;
 233         }
 234         return ret;
 235 }
 236
 237 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 238 {
 239         char *date;
 240         unsigned int namelen;
 241         unsigned long time;
 242         int tz, ret;
 243
 244         date = strchr(line, '>');
 245         if (!date)
 246                 return 0;
 247         namelen = ++date - line;
 248         time = strtoul(date, &date, 10);
 249         tz = strtol(date, NULL, 10);
 250
 251         ret = sprintf(buf, "%s: %.*s\n", what, namelen, line);
 252         if (fmt == CMIT_FMT_MEDIUM)
 253                 ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
 254         return ret;
 255 }
 256
 257 static int is_empty_line(const char *line, int len)
 258 {
 259         while (len && isspace(line[len-1]))
 260                 len--;
 261         return !len;
 262 }
 263
 264 static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
 265 {
 266         int offset = 0;
 267         switch (parents) {
 268         case 1:
 269                 break;
 270         case 2:
 271                 /* Go back to the previous line: 40 characters of previous parent, and one '\n' */
 272                 offset = sprintf(buf, "Merge: %.40s\n", line-41);
 273                 /* Fallthrough */
 274         default:
 275                 /* Replace the previous '\n' with a space */
 276                 buf[offset-1] = ' ';
 277                 offset += sprintf(buf + offset, "%.40s\n", line+7);
 278         }
 279         return offset;
 280 }
 281
 282 unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
 283 {
 284         int hdr = 1, body = 0;
 285         unsigned long offset = 0;
 286         int parents = 0;
 287
 288         for (;;) {
 289                 const char *line = msg;
 290                 int linelen = get_one_line(msg, len);
 291
 292                 if (!linelen)
 293                         break;
 294
 295                 /*
 296                  * We want some slop for indentation and a possible
 297                  * final "...". Thus the "+ 20".
 298                  */
 299                 if (offset + linelen + 20 > space) {
 300                         memcpy(buf + offset, "    ...\n", 8);
 301                         offset += 8;
 302                         break;
 303                 }
 304
 305                 msg += linelen;
 306                 len -= linelen;
 307                 if (hdr) {
 308                         if (linelen == 1) {
 309                                 hdr = 0;
 310                                 buf[offset++] = '\n';
 311                                 continue;
 312                         }
 313                         if (fmt == CMIT_FMT_RAW) {
 314                                 memcpy(buf + offset, line, linelen);
 315                                 offset += linelen;
 316                                 continue;
 317                         }
 318                         if (!memcmp(line, "parent ", 7)) {
 319                                 if (linelen != 48)
 320                                         die("bad parent line in commit");
 321                                 offset += add_parent_info(fmt, buf + offset, line, ++parents);
 322                         }
 323                         if (!memcmp(line, "author ", 7))
 324                                 offset += add_user_info("Author", fmt, buf + offset, line + 7);
 325                         if (fmt == CMIT_FMT_FULL) {
 326                                 if (!memcmp(line, "committer ", 10))
 327                                         offset += add_user_info("Commit", fmt, buf + offset, line + 10);
 328                         }
 329                         continue;
 330                 }
 331
 332                 if (is_empty_line(line, linelen)) {
 333                         if (!body)
 334                                 continue;
 335                         if (fmt == CMIT_FMT_SHORT)
 336                                 break;
 337                 } else {
 338                         body = 1;
 339                 }
 340                 memset(buf + offset, ' ', 4);
 341                 memcpy(buf + offset + 4, line, linelen);
 342                 offset += linelen + 4;
 343         }
 344         /* Make sure there is an EOLN */
 345         if (buf[offset - 1] != '\n')
 346                 buf[offset++] = '\n';
 347         buf[offset] = '\0';
 348         return offset;
 349 }
 350
 351 struct commit *pop_commit(struct commit_list **stack)
 352 {
 353         struct commit_list *top = *stack;
 354         struct commit *item = top ? top->item : NULL;
 355
 356         if (top) {
 357                 *stack = top->next;
 358                 free(top);
 359         }
 360         return item;
 361 }
 362
 363 int count_parents(struct commit * commit)
 364 {
 365         int count = 0;
 366         struct commit_list * parents = commit->parents;
 367         for (count=0;parents; parents=parents->next,count++)
 368           ;
 369         return count;
 370 }
 371
 372 /*
 373  * Performs an in-place topological sort on the list supplied.
 374  */
 375 void sort_in_topological_order(struct commit_list ** list)
 376 {
 377         struct commit_list * next = *list;
 378         struct commit_list * work = NULL;
 379         struct commit_list ** pptr = list;
 380         struct sort_node * nodes;
 381         struct sort_node * next_nodes;
 382         int count = 0;
 383
 384         /* determine the size of the list */
 385         while (next) {
 386                 next = next->next;
 387                 count++;
 388         }
 389         /* allocate an array to help sort the list */
 390         nodes = xcalloc(count, sizeof(*nodes));
 391         /* link the list to the array */
 392         next_nodes = nodes;
 393         next=*list;
 394         while (next) {
 395                 next_nodes->list_item = next;
 396                 next->item->object.util = next_nodes;
 397                 next_nodes++;
 398                 next = next->next;
 399         }
 400         /* update the indegree */
 401         next=*list;
 402         while (next) {
 403                 struct commit_list * parents = next->item->parents;
 404                 while (parents) {
 405                         struct commit * parent=parents->item;
 406                         struct sort_node * pn = (struct sort_node *)parent->object.util;
 407
 408                         if (pn)
 409                                 pn->indegree++;
 410                         parents=parents->next;
 411                 }
 412                 next=next->next;
 413         }
 414         /*
 415          * find the tips
 416          *
 417          * tips are nodes not reachable from any other node in the list
 418          *
 419          * the tips serve as a starting set for the work queue.
 420          */
 421         next=*list;
 422         while (next) {
 423                 struct sort_node * node = (struct sort_node *)next->item->object.util;
 424
 425                 if (node->indegree == 0) {
 426                         commit_list_insert(next->item, &work);
 427                 }
 428                 next=next->next;
 429         }
 430         /* process the list in topological order */
 431         while (work) {
 432                 struct commit * work_item = pop_commit(&work);
 433                 struct sort_node * work_node = (struct sort_node *)work_item->object.util;
 434                 struct commit_list * parents = work_item->parents;
 435
 436                 while (parents) {
 437                         struct commit * parent=parents->item;
 438                         struct sort_node * pn = (struct sort_node *)parent->object.util;
 439
 440                         if (pn) {
 441                                 /*
 442                                  * parents are only enqueued for emission
 443                                  * when all their children have been emitted thereby
 444                                  * guaranteeing topological order.
 445                                  */
 446                                 pn->indegree--;
 447                                 if (!pn->indegree)
 448                                         commit_list_insert(parent, &work);
 449                         }
 450                         parents=parents->next;
 451                 }
 452                 /*
 453                  * work_item is a commit all of whose children
 454                  * have already been emitted. we can emit it now.
 455                  */
 456                 *pptr = work_node->list_item;
 457                 pptr = &(*pptr)->next;
 458                 *pptr = NULL;
 459                 work_item->object.util = NULL;
 460         }
 461         free(nodes);
 462 }