Don't add references to objects we couldn't find.
[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 = malloc(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(struct commit *item)
45 {
46         char type[20];
47         void * buffer, *bufptr;
48         unsigned long size;
49         unsigned char parent[20];
50         if (item->object.parsed)
51                 return 0;
52         item->object.parsed = 1;
53         buffer = bufptr = read_sha1_file(item->object.sha1, type, &size);
54         if (!buffer)
55                 return error("Could not read %s",
56                              sha1_to_hex(item->object.sha1));
57         if (strcmp(type, commit_type))
58                 return error("Object %s not a commit",
59                              sha1_to_hex(item->object.sha1));
60         get_sha1_hex(bufptr + 5, parent);
61         item->tree = lookup_tree(parent);
62         if (item->tree)
63                 add_ref(&item->object, &item->tree->object);
64         bufptr += 46; /* "tree " + "hex sha1" + "\n" */
65         while (!memcmp(bufptr, "parent ", 7) &&
66                !get_sha1_hex(bufptr + 7, parent)) {
67                 struct commit *new_parent = lookup_commit(parent);
68                 if (new_parent) {
69                         commit_list_insert(new_parent, &item->parents);
70                         add_ref(&item->object, &new_parent->object);
71                 }
72                 bufptr += 48;
73         }
74         item->date = parse_commit_date(bufptr);
75         free(buffer);
76         return 0;
77 }
78
79 void commit_list_insert(struct commit *item, struct commit_list **list_p)
80 {
81         struct commit_list *new_list = malloc(sizeof(struct commit_list));
82         new_list->item = item;
83         new_list->next = *list_p;
84         *list_p = new_list;
85 }
86
87 void free_commit_list(struct commit_list *list)
88 {
89         while (list) {
90                 struct commit_list *temp = list;
91                 list = temp->next;
92                 free(temp);
93         }
94 }
95
96 static void insert_by_date(struct commit_list **list, struct commit *item)
97 {
98         struct commit_list **pp = list;
99         struct commit_list *p;
100         while ((p = *pp) != NULL) {
101                 if (p->item->date < item->date) {
102                         break;
103                 }
104                 pp = &p->next;
105         }
106         commit_list_insert(item, pp);
107 }
108
109         
110 void sort_by_date(struct commit_list **list)
111 {
112         struct commit_list *ret = NULL;
113         while (*list) {
114                 insert_by_date(&ret, (*list)->item);
115                 *list = (*list)->next;
116         }
117         *list = ret;
118 }
119
120 struct commit *pop_most_recent_commit(struct commit_list **list,
121                                       unsigned int mark)
122 {
123         struct commit *ret = (*list)->item;
124         struct commit_list *parents = ret->parents;
125         struct commit_list *old = *list;
126
127         *list = (*list)->next;
128         free(old);
129
130         while (parents) {
131                 struct commit *commit = parents->item;
132                 parse_commit(commit);
133                 if (!(commit->object.flags & mark)) {
134                         commit->object.flags |= mark;
135                         insert_by_date(list, commit);
136                 }
137                 parents = parents->next;
138         }
139         return ret;
140 }