tutorial.txt: start describing how to copy repositories
[git.git] / commit.c
blobde5e94d1dd5eabc5dfdf6935cb90096c3d37c13e
1 #include "tag.h"
2 #include "commit.h"
3 #include "cache.h"
5 const char *commit_type = "commit";
7 static struct commit *check_commit(struct object *obj, unsigned char *sha1)
9 if (obj->type != commit_type) {
10 error("Object %s is a %s, not a commit",
11 sha1_to_hex(sha1), obj->type);
12 return NULL;
14 return (struct commit *) obj;
17 struct commit *lookup_commit_reference(unsigned char *sha1)
19 struct object *obj = parse_object(sha1);
21 if (!obj)
22 return NULL;
23 if (obj->type == tag_type)
24 obj = ((struct tag *)obj)->tagged;
25 return check_commit(obj, sha1);
28 struct commit *lookup_commit(unsigned char *sha1)
30 struct object *obj = lookup_object(sha1);
31 if (!obj) {
32 struct commit *ret = xmalloc(sizeof(struct commit));
33 memset(ret, 0, sizeof(struct commit));
34 created_object(sha1, &ret->object);
35 ret->object.type = commit_type;
36 return ret;
38 if (!obj->type)
39 obj->type = commit_type;
40 return check_commit(obj, sha1);
43 static unsigned long parse_commit_date(const char *buf)
45 unsigned long date;
47 if (memcmp(buf, "author", 6))
48 return 0;
49 while (*buf++ != '\n')
50 /* nada */;
51 if (memcmp(buf, "committer", 9))
52 return 0;
53 while (*buf++ != '>')
54 /* nada */;
55 date = strtoul(buf, NULL, 10);
56 if (date == ULONG_MAX)
57 date = 0;
58 return date;
61 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
63 void *bufptr = buffer;
64 unsigned char parent[20];
66 if (item->object.parsed)
67 return 0;
68 item->object.parsed = 1;
69 get_sha1_hex(bufptr + 5, parent);
70 item->tree = lookup_tree(parent);
71 if (item->tree)
72 add_ref(&item->object, &item->tree->object);
73 bufptr += 46; /* "tree " + "hex sha1" + "\n" */
74 while (!memcmp(bufptr, "parent ", 7) &&
75 !get_sha1_hex(bufptr + 7, parent)) {
76 struct commit *new_parent = lookup_commit(parent);
77 if (new_parent) {
78 commit_list_insert(new_parent, &item->parents);
79 add_ref(&item->object, &new_parent->object);
81 bufptr += 48;
83 item->date = parse_commit_date(bufptr);
84 return 0;
87 int parse_commit(struct commit *item)
89 char type[20];
90 void *buffer;
91 unsigned long size;
92 int ret;
94 if (item->object.parsed)
95 return 0;
96 buffer = read_sha1_file(item->object.sha1, type, &size);
97 if (!buffer)
98 return error("Could not read %s",
99 sha1_to_hex(item->object.sha1));
100 if (strcmp(type, commit_type)) {
101 free(buffer);
102 return error("Object %s not a commit",
103 sha1_to_hex(item->object.sha1));
105 ret = parse_commit_buffer(item, buffer, size);
106 if (!ret) {
107 item->buffer = buffer;
108 return 0;
110 free(buffer);
111 return ret;
114 struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
116 struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
117 new_list->item = item;
118 new_list->next = *list_p;
119 *list_p = new_list;
120 return new_list;
123 void free_commit_list(struct commit_list *list)
125 while (list) {
126 struct commit_list *temp = list;
127 list = temp->next;
128 free(temp);
132 static void insert_by_date(struct commit_list **list, struct commit *item)
134 struct commit_list **pp = list;
135 struct commit_list *p;
136 while ((p = *pp) != NULL) {
137 if (p->item->date < item->date) {
138 break;
140 pp = &p->next;
142 commit_list_insert(item, pp);
146 void sort_by_date(struct commit_list **list)
148 struct commit_list *ret = NULL;
149 while (*list) {
150 insert_by_date(&ret, (*list)->item);
151 *list = (*list)->next;
153 *list = ret;
156 struct commit *pop_most_recent_commit(struct commit_list **list,
157 unsigned int mark)
159 struct commit *ret = (*list)->item;
160 struct commit_list *parents = ret->parents;
161 struct commit_list *old = *list;
163 *list = (*list)->next;
164 free(old);
166 while (parents) {
167 struct commit *commit = parents->item;
168 parse_commit(commit);
169 if (!(commit->object.flags & mark)) {
170 commit->object.flags |= mark;
171 insert_by_date(list, commit);
173 parents = parents->next;
175 return ret;
179 * Generic support for pretty-printing the header
181 static int get_one_line(const char *msg, unsigned long len)
183 int ret = 0;
185 while (len--) {
186 char c = *msg++;
187 ret++;
188 if (c == '\n')
189 break;
190 if (!c)
191 return 0;
193 return ret;
196 static int add_author_info(char *buf, const char *line, int len)
198 char *date;
199 unsigned int namelen;
200 unsigned long time;
201 int tz;
203 line += strlen("author ");
204 date = strchr(line, '>');
205 if (!date)
206 return 0;
207 namelen = ++date - line;
208 time = strtoul(date, &date, 10);
209 tz = strtol(date, NULL, 10);
211 return sprintf(buf, "Author: %.*s\nDate: %s\n",
212 namelen, line,
213 show_date(time, tz));
216 unsigned long pretty_print_commit(const char *msg, unsigned long len, char *buf, unsigned long space)
218 int hdr = 1;
219 unsigned long offset = 0;
221 for (;;) {
222 const char *line = msg;
223 int linelen = get_one_line(msg, len);
225 if (!linelen)
226 break;
229 * We want some slop for indentation and a possible
230 * final "...". Thus the "+ 20".
232 if (offset + linelen + 20 > space) {
233 memcpy(buf + offset, " ...\n", 8);
234 offset += 8;
235 break;
238 msg += linelen;
239 len -= linelen;
240 if (linelen == 1)
241 hdr = 0;
242 if (hdr) {
243 if (!memcmp(line, "author ", 7))
244 offset += add_author_info(buf + offset, line, linelen);
245 continue;
247 memset(buf + offset, ' ', 4);
248 memcpy(buf + offset + 4, line, linelen);
249 offset += linelen + 4;
251 /* Make sure there is an EOLN */
252 if (buf[offset - 1] != '\n')
253 buf[offset++] = '\n';
254 buf[offset] = '\0';
255 return offset;