git-apply: implement "diffstat" output
[git] / commit.c
1 #include "tag.h"
2 #include "commit.h"
3 #include "cache.h"
4
5 const char *commit_type = "commit";
6
7 static struct commit *check_commit(struct object *obj, unsigned char *sha1)
8 {
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;
13         }
14         return (struct commit *) obj;
15 }
16
17 struct commit *lookup_commit_reference(unsigned char *sha1)
18 {
19         struct object *obj = parse_object(sha1);
20
21         if (!obj)
22                 return NULL;
23         if (obj->type == tag_type)
24                 obj = ((struct tag *)obj)->tagged;
25         return check_commit(obj, sha1);
26 }
27
28 struct commit *lookup_commit(unsigned char *sha1)
29 {
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;
37         }
38         if (!obj->type)
39                 obj->type = commit_type;
40         return check_commit(obj, sha1);
41 }
42
43 static unsigned long parse_commit_date(const char *buf)
44 {
45         unsigned long date;
46
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;
59 }
60
61 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
62 {
63         void *bufptr = buffer;
64         unsigned char parent[20];
65
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);
80                 }
81                 bufptr += 48;
82         }
83         item->date = parse_commit_date(bufptr);
84         return 0;
85 }
86
87 int parse_commit(struct commit *item)
88 {
89         char type[20];
90         void *buffer;
91         unsigned long size;
92         int ret;
93
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));
104         }
105         ret = parse_commit_buffer(item, buffer, size);
106         if (!ret) {
107                 item->buffer = buffer;
108                 return 0;
109         }
110         free(buffer);
111         return ret;
112 }
113
114 void commit_list_insert(struct commit *item, struct commit_list **list_p)
115 {
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 }
121
122 void free_commit_list(struct commit_list *list)
123 {
124         while (list) {
125                 struct commit_list *temp = list;
126                 list = temp->next;
127                 free(temp);
128         }
129 }
130
131 static void insert_by_date(struct commit_list **list, struct commit *item)
132 {
133         struct commit_list **pp = list;
134         struct commit_list *p;
135         while ((p = *pp) != NULL) {
136                 if (p->item->date < item->date) {
137                         break;
138                 }
139                 pp = &p->next;
140         }
141         commit_list_insert(item, pp);
142 }
143
144         
145 void sort_by_date(struct commit_list **list)
146 {
147         struct commit_list *ret = NULL;
148         while (*list) {
149                 insert_by_date(&ret, (*list)->item);
150                 *list = (*list)->next;
151         }
152         *list = ret;
153 }
154
155 struct commit *pop_most_recent_commit(struct commit_list **list,
156                                       unsigned int mark)
157 {
158         struct commit *ret = (*list)->item;
159         struct commit_list *parents = ret->parents;
160         struct commit_list *old = *list;
161
162         *list = (*list)->next;
163         free(old);
164
165         while (parents) {
166                 struct commit *commit = parents->item;
167                 parse_commit(commit);
168                 if (!(commit->object.flags & mark)) {
169                         commit->object.flags |= mark;
170                         insert_by_date(list, commit);
171                 }
172                 parents = parents->next;
173         }
174         return ret;
175 }