diff-delta.c: allow delta with empty blob.
[git] / tree.c
1 #include "tree.h"
2 #include "blob.h"
3 #include "commit.h"
4 #include "tag.h"
5 #include "cache.h"
6 #include <stdlib.h>
7
8 const char *tree_type = "tree";
9
10 static int read_one_entry(unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
11 {
12         int len;
13         unsigned int size;
14         struct cache_entry *ce;
15
16         if (S_ISDIR(mode))
17                 return READ_TREE_RECURSIVE;
18
19         len = strlen(pathname);
20         size = cache_entry_size(baselen + len);
21         ce = xmalloc(size);
22
23         memset(ce, 0, size);
24
25         ce->ce_mode = create_ce_mode(mode);
26         ce->ce_flags = create_ce_flags(baselen + len, stage);
27         memcpy(ce->name, base, baselen);
28         memcpy(ce->name + baselen, pathname, len+1);
29         memcpy(ce->sha1, sha1, 20);
30         return add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
31 }
32
33 static int match_tree_entry(const char *base, int baselen, const char *path, unsigned int mode, const char **paths)
34 {
35         const char *match;
36         int pathlen;
37
38         if (!paths)
39                 return 1;
40         pathlen = strlen(path);
41         while ((match = *paths++) != NULL) {
42                 int matchlen = strlen(match);
43
44                 if (baselen >= matchlen) {
45                         /* If it doesn't match, move along... */
46                         if (strncmp(base, match, matchlen))
47                                 continue;
48                         /* The base is a subdirectory of a path which was specified. */
49                         return 1;
50                 }
51
52                 /* Does the base match? */
53                 if (strncmp(base, match, baselen))
54                         continue;
55
56                 match += baselen;
57                 matchlen -= baselen;
58
59                 if (pathlen > matchlen)
60                         continue;
61
62                 if (matchlen > pathlen) {
63                         if (match[pathlen] != '/')
64                                 continue;
65                         if (!S_ISDIR(mode))
66                                 continue;
67                 }
68
69                 if (strncmp(path, match, pathlen))
70                         continue;
71
72                 return 1;
73         }
74         return 0;
75 }
76
77 int read_tree_recursive(void *buffer, unsigned long size,
78                         const char *base, int baselen,
79                         int stage, const char **match,
80                         read_tree_fn_t fn)
81 {
82         while (size) {
83                 int len = strlen(buffer)+1;
84                 unsigned char *sha1 = buffer + len;
85                 char *path = strchr(buffer, ' ')+1;
86                 unsigned int mode;
87
88                 if (size < len + 20 || sscanf(buffer, "%o", &mode) != 1)
89                         return -1;
90
91                 buffer = sha1 + 20;
92                 size -= len + 20;
93
94                 if (!match_tree_entry(base, baselen, path, mode, match))
95                         continue;
96
97                 switch (fn(sha1, base, baselen, path, mode, stage)) {
98                 case 0:
99                         continue;
100                 case READ_TREE_RECURSIVE:
101                         break;;
102                 default:
103                         return -1;
104                 }
105                 if (S_ISDIR(mode)) {
106                         int retval;
107                         int pathlen = strlen(path);
108                         char *newbase;
109                         void *eltbuf;
110                         char elttype[20];
111                         unsigned long eltsize;
112
113                         eltbuf = read_sha1_file(sha1, elttype, &eltsize);
114                         if (!eltbuf || strcmp(elttype, "tree")) {
115                                 if (eltbuf) free(eltbuf);
116                                 return -1;
117                         }
118                         newbase = xmalloc(baselen + 1 + pathlen);
119                         memcpy(newbase, base, baselen);
120                         memcpy(newbase + baselen, path, pathlen);
121                         newbase[baselen + pathlen] = '/';
122                         retval = read_tree_recursive(eltbuf, eltsize,
123                                                      newbase,
124                                                      baselen + pathlen + 1,
125                                                      stage, match, fn);
126                         free(eltbuf);
127                         free(newbase);
128                         if (retval)
129                                 return -1;
130                         continue;
131                 }
132         }
133         return 0;
134 }
135
136 int read_tree(void *buffer, unsigned long size, int stage, const char **match)
137 {
138         return read_tree_recursive(buffer, size, "", 0, stage, match, read_one_entry);
139 }
140
141 struct tree *lookup_tree(const unsigned char *sha1)
142 {
143         struct object *obj = lookup_object(sha1);
144         if (!obj) {
145                 struct tree *ret = xmalloc(sizeof(struct tree));
146                 memset(ret, 0, sizeof(struct tree));
147                 created_object(sha1, &ret->object);
148                 ret->object.type = tree_type;
149                 return ret;
150         }
151         if (!obj->type)
152                 obj->type = tree_type;
153         if (obj->type != tree_type) {
154                 error("Object %s is a %s, not a tree", 
155                       sha1_to_hex(sha1), obj->type);
156                 return NULL;
157         }
158         return (struct tree *) obj;
159 }
160
161 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
162 {
163         void *bufptr = buffer;
164         struct tree_entry_list **list_p;
165         int n_refs = 0;
166
167         if (item->object.parsed)
168                 return 0;
169         item->object.parsed = 1;
170         list_p = &item->entries;
171         while (size) {
172                 struct object *obj;
173                 struct tree_entry_list *entry;
174                 int len = 1+strlen(bufptr);
175                 unsigned char *file_sha1 = bufptr + len;
176                 char *path = strchr(bufptr, ' ');
177                 unsigned int mode;
178                 if (size < len + 20 || !path || 
179                     sscanf(bufptr, "%o", &mode) != 1)
180                         return -1;
181
182                 entry = xmalloc(sizeof(struct tree_entry_list));
183                 entry->name = strdup(path + 1);
184                 entry->directory = S_ISDIR(mode) != 0;
185                 entry->executable = (mode & S_IXUSR) != 0;
186                 entry->symlink = S_ISLNK(mode) != 0;
187                 entry->zeropad = *(char *)bufptr == '0';
188                 entry->mode = mode;
189                 entry->next = NULL;
190
191                 bufptr += len + 20;
192                 size -= len + 20;
193
194                 if (entry->directory) {
195                         entry->item.tree = lookup_tree(file_sha1);
196                         obj = &entry->item.tree->object;
197                 } else {
198                         entry->item.blob = lookup_blob(file_sha1);
199                         obj = &entry->item.blob->object;
200                 }
201                 if (obj)
202                         n_refs++;
203                 *list_p = entry;
204                 list_p = &entry->next;
205         }
206
207         if (track_object_refs) {
208                 struct tree_entry_list *entry;
209                 unsigned i = 0;
210                 struct object_refs *refs = alloc_object_refs(n_refs);
211                 for (entry = item->entries; entry; entry = entry->next)
212                         refs->ref[i++] = entry->item.any;
213                 set_object_refs(&item->object, refs);
214         }
215
216         return 0;
217 }
218
219 int parse_tree(struct tree *item)
220 {
221          char type[20];
222          void *buffer;
223          unsigned long size;
224          int ret;
225
226         if (item->object.parsed)
227                 return 0;
228         buffer = read_sha1_file(item->object.sha1, type, &size);
229         if (!buffer)
230                 return error("Could not read %s",
231                              sha1_to_hex(item->object.sha1));
232         if (strcmp(type, tree_type)) {
233                 free(buffer);
234                 return error("Object %s not a tree",
235                              sha1_to_hex(item->object.sha1));
236         }
237         ret = parse_tree_buffer(item, buffer, size);
238         free(buffer);
239         return ret;
240 }
241
242 struct tree *parse_tree_indirect(const unsigned char *sha1)
243 {
244         struct object *obj = parse_object(sha1);
245         do {
246                 if (!obj)
247                         return NULL;
248                 if (obj->type == tree_type)
249                         return (struct tree *) obj;
250                 else if (obj->type == commit_type)
251                         obj = &(((struct commit *) obj)->tree->object);
252                 else if (obj->type == tag_type)
253                         obj = ((struct tag *) obj)->tagged;
254                 else
255                         return NULL;
256                 if (!obj->parsed)
257                         parse_object(obj->sha1);
258         } while (1);
259 }