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