706c7cba08ebc2100c2dbf63ed1238f39324f750
[git.git] / commit.c
1 #include "commit.h"
2 #include "cache.h"
3 #include <string.h>
4 #include <limits.h>
5
6 const char *commit_type = "commit";
7
8 struct commit *lookup_commit(unsigned char *sha1)
9 {
10         struct object *obj = lookup_object(sha1);
11         if (!obj) {
12                 struct commit *ret = xmalloc(sizeof(struct commit));
13                 memset(ret, 0, sizeof(struct commit));
14                 created_object(sha1, &ret->object);
15                 ret->object.type = commit_type;
16                 return ret;
17         }
18         if (obj->type != commit_type) {
19                 error("Object %s is a %s, not a commit", 
20                       sha1_to_hex(sha1), obj->type);
21                 return NULL;
22         }
23         return (struct commit *) obj;
24 }
25
26 static unsigned long parse_commit_date(const char *buf)
27 {
28         unsigned long date;
29
30         if (memcmp(buf, "author", 6))
31                 return 0;
32         while (*buf++ != '\n')
33                 /* nada */;
34         if (memcmp(buf, "committer", 9))
35                 return 0;
36         while (*buf++ != '>')
37                 /* nada */;
38         date = strtoul(buf, NULL, 10);
39         if (date == ULONG_MAX)
40                 date = 0;
41         return date;
42 }
43
44 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
45 {
46         void *bufptr = buffer;
47         unsigned char parent[20];
48
49         if (item->object.parsed)
50                 return 0;
51         item->object.parsed = 1;
52         get_sha1_hex(bufptr + 5, parent);
53         item->tree = lookup_tree(parent);
54         if (item->tree)
55                 add_ref(&item->object, &item->tree->object);
56         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
57         while (!memcmp(bufptr, "parent ", 7) &&
58                !get_sha1_hex(bufptr + 7, parent)) {
59                 struct commit *new_parent = lookup_commit(parent);
60                 if (new_parent) {
61                         commit_list_insert(new_parent, &item->parents);
62                         add_ref(&item->object, &new_parent->object);
63                 }
64                 bufptr += 48;
65         }
66         item->date = parse_commit_date(bufptr);
67         return 0;
68 }
69
70 int parse_commit(struct commit *item)
71 {
72         char type[20];
73         void *buffer;
74         unsigned long size;
75         int ret;
76
77         if (item->object.parsed)
78                 return 0;
79         buffer = read_sha1_file(item->object.sha1, type, &size);
80         if (!buffer)
81                 return error("Could not read %s",
82                              sha1_to_hex(item->object.sha1));
83         if (strcmp(type, commit_type)) {
84                 free(buffer);
85                 return error("Object %s not a commit",
86                              sha1_to_hex(item->object.sha1));
87         }
88         ret = parse_commit_buffer(item, buffer, size);
89         free(buffer);
90         return ret;
91 }
92
93 void commit_list_insert(struct commit *item, struct commit_list **list_p)
94 {
95         struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
96         new_list->item = item;
97         new_list->next = *list_p;
98         *list_p = new_list;
99 }
100
101 void free_commit_list(struct commit_list *list)
102 {
103         while (list) {
104                 struct commit_list *temp = list;
105                 list = temp->next;
106                 free(temp);
107         }
108 }
109
110 static void insert_by_date(struct commit_list **list, struct commit *item)
111 {
112         struct commit_list **pp = list;
113         struct commit_list *p;
114         while ((p = *pp) != NULL) {
115                 if (p->item->date < item->date) {
116                         break;
117                 }
118                 pp = &p->next;
119         }
120         commit_list_insert(item, pp);
121 }
122
123         
124 void sort_by_date(struct commit_list **list)
125 {
126         struct commit_list *ret = NULL;
127         while (*list) {
128                 insert_by_date(&ret, (*list)->item);
129                 *list = (*list)->next;
130         }
131         *list = ret;
132 }
133
134 struct commit *pop_most_recent_commit(struct commit_list **list,
135                                       unsigned int mark)
136 {
137         struct commit *ret = (*list)->item;
138         struct commit_list *parents = ret->parents;
139         struct commit_list *old = *list;
140
141         *list = (*list)->next;
142         free(old);
143
144         while (parents) {
145                 struct commit *commit = parents->item;
146                 parse_commit(commit);
147                 if (!(commit->object.flags & mark)) {
148                         commit->object.flags |= mark;
149                         insert_by_date(list, commit);
150                 }
151                 parents = parents->next;
152         }
153         return ret;
154 }