git-apply: find offset fragments, and really apply them
[git] / tree.c
1 #include "tree.h"
2 #include "blob.h"
3 #include "cache.h"
4 #include <stdlib.h>
5
6 const char *tree_type = "tree";
7
8 static int read_one_entry(unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
9 {
10         int len = strlen(pathname);
11         unsigned int size = cache_entry_size(baselen + len);
12         struct cache_entry *ce = xmalloc(size);
13
14         memset(ce, 0, size);
15
16         ce->ce_mode = create_ce_mode(mode);
17         ce->ce_flags = create_ce_flags(baselen + len, stage);
18         memcpy(ce->name, base, baselen);
19         memcpy(ce->name + baselen, pathname, len+1);
20         memcpy(ce->sha1, sha1, 20);
21         return add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
22 }
23
24 static int read_tree_recursive(void *buffer, unsigned long size,
25                                const char *base, int baselen, int stage)
26 {
27         while (size) {
28                 int len = strlen(buffer)+1;
29                 unsigned char *sha1 = buffer + len;
30                 char *path = strchr(buffer, ' ')+1;
31                 unsigned int mode;
32
33                 if (size < len + 20 || sscanf(buffer, "%o", &mode) != 1)
34                         return -1;
35
36                 buffer = sha1 + 20;
37                 size -= len + 20;
38
39                 if (S_ISDIR(mode)) {
40                         int retval;
41                         int pathlen = strlen(path);
42                         char *newbase;
43                         void *eltbuf;
44                         char elttype[20];
45                         unsigned long eltsize;
46
47                         eltbuf = read_sha1_file(sha1, elttype, &eltsize);
48                         if (!eltbuf || strcmp(elttype, "tree")) {
49                                 if (eltbuf) free(eltbuf);
50                                 return -1;
51                         }
52                         newbase = xmalloc(baselen + 1 + pathlen);
53                         memcpy(newbase, base, baselen);
54                         memcpy(newbase + baselen, path, pathlen);
55                         newbase[baselen + pathlen] = '/';
56                         retval = read_tree_recursive(eltbuf, eltsize,
57                                                      newbase,
58                                                      baselen + pathlen + 1, stage);
59                         free(eltbuf);
60                         free(newbase);
61                         if (retval)
62                                 return -1;
63                         continue;
64                 }
65                 if (read_one_entry(sha1, base, baselen, path, mode, stage) < 0)
66                         return -1;
67         }
68         return 0;
69 }
70
71 int read_tree(void *buffer, unsigned long size, int stage)
72 {
73         return read_tree_recursive(buffer, size, "", 0, stage);
74 }
75
76 struct tree *lookup_tree(unsigned char *sha1)
77 {
78         struct object *obj = lookup_object(sha1);
79         if (!obj) {
80                 struct tree *ret = xmalloc(sizeof(struct tree));
81                 memset(ret, 0, sizeof(struct tree));
82                 created_object(sha1, &ret->object);
83                 ret->object.type = tree_type;
84                 return ret;
85         }
86         if (!obj->type)
87                 obj->type = tree_type;
88         if (obj->type != tree_type) {
89                 error("Object %s is a %s, not a tree", 
90                       sha1_to_hex(sha1), obj->type);
91                 return NULL;
92         }
93         return (struct tree *) obj;
94 }
95
96 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
97 {
98         void *bufptr = buffer;
99         struct tree_entry_list **list_p;
100
101         if (item->object.parsed)
102                 return 0;
103         item->object.parsed = 1;
104         list_p = &item->entries;
105         while (size) {
106                 struct object *obj;
107                 struct tree_entry_list *entry;
108                 int len = 1+strlen(bufptr);
109                 unsigned char *file_sha1 = bufptr + len;
110                 char *path = strchr(bufptr, ' ');
111                 unsigned int mode;
112                 if (size < len + 20 || !path || 
113                     sscanf(bufptr, "%o", &mode) != 1)
114                         return -1;
115
116                 entry = xmalloc(sizeof(struct tree_entry_list));
117                 entry->name = strdup(path + 1);
118                 entry->directory = S_ISDIR(mode) != 0;
119                 entry->executable = (mode & S_IXUSR) != 0;
120                 entry->symlink = S_ISLNK(mode) != 0;
121                 entry->mode = mode;
122                 entry->next = NULL;
123
124                 bufptr += len + 20;
125                 size -= len + 20;
126
127                 if (entry->directory) {
128                         entry->item.tree = lookup_tree(file_sha1);
129                         obj = &entry->item.tree->object;
130                 } else {
131                         entry->item.blob = lookup_blob(file_sha1);
132                         obj = &entry->item.blob->object;
133                 }
134                 if (obj)
135                         add_ref(&item->object, obj);
136                 entry->parent = NULL; /* needs to be filled by the user */
137                 *list_p = entry;
138                 list_p = &entry->next;
139         }
140         return 0;
141 }
142
143 int parse_tree(struct tree *item)
144 {
145          char type[20];
146          void *buffer;
147          unsigned long size;
148          int ret;
149
150         if (item->object.parsed)
151                 return 0;
152         buffer = read_sha1_file(item->object.sha1, type, &size);
153         if (!buffer)
154                 return error("Could not read %s",
155                              sha1_to_hex(item->object.sha1));
156         if (strcmp(type, tree_type)) {
157                 free(buffer);
158                 return error("Object %s not a tree",
159                              sha1_to_hex(item->object.sha1));
160         }
161         ret = parse_tree_buffer(item, buffer, size);
162         free(buffer);
163         return ret;
164 }