Code

GIT 1.5.4.4
[git.git] / tree-walk.c
1 #include "cache.h"
2 #include "tree-walk.h"
3 #include "tree.h"
5 static const char *get_mode(const char *str, unsigned int *modep)
6 {
7         unsigned char c;
8         unsigned int mode = 0;
10         if (*str == ' ')
11                 return NULL;
13         while ((c = *str++) != ' ') {
14                 if (c < '0' || c > '7')
15                         return NULL;
16                 mode = (mode << 3) + (c - '0');
17         }
18         *modep = mode;
19         return str;
20 }
22 static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size)
23 {
24         const char *path;
25         unsigned int mode, len;
27         if (size < 24 || buf[size - 21])
28                 die("corrupt tree file");
30         path = get_mode(buf, &mode);
31         if (!path || !*path)
32                 die("corrupt tree file");
33         len = strlen(path) + 1;
35         /* Initialize the descriptor entry */
36         desc->entry.path = path;
37         desc->entry.mode = mode;
38         desc->entry.sha1 = (const unsigned char *)(path + len);
39 }
41 void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
42 {
43         desc->buffer = buffer;
44         desc->size = size;
45         if (size)
46                 decode_tree_entry(desc, buffer, size);
47 }
49 void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
50 {
51         unsigned long size = 0;
52         void *buf = NULL;
54         if (sha1) {
55                 buf = read_object_with_reference(sha1, tree_type, &size, NULL);
56                 if (!buf)
57                         die("unable to read tree %s", sha1_to_hex(sha1));
58         }
59         init_tree_desc(desc, buf, size);
60         return buf;
61 }
63 static int entry_compare(struct name_entry *a, struct name_entry *b)
64 {
65         return base_name_compare(
66                         a->path, tree_entry_len(a->path, a->sha1), a->mode,
67                         b->path, tree_entry_len(b->path, b->sha1), b->mode);
68 }
70 static void entry_clear(struct name_entry *a)
71 {
72         memset(a, 0, sizeof(*a));
73 }
75 static void entry_extract(struct tree_desc *t, struct name_entry *a)
76 {
77         *a = t->entry;
78 }
80 void update_tree_entry(struct tree_desc *desc)
81 {
82         const void *buf = desc->buffer;
83         const unsigned char *end = desc->entry.sha1 + 20;
84         unsigned long size = desc->size;
85         unsigned long len = end - (const unsigned char *)buf;
87         if (size < len)
88                 die("corrupt tree file");
89         buf = end;
90         size -= len;
91         desc->buffer = buf;
92         desc->size = size;
93         if (size)
94                 decode_tree_entry(desc, buf, size);
95 }
97 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
98 {
99         if (!desc->size)
100                 return 0;
102         *entry = desc->entry;
103         update_tree_entry(desc);
104         return 1;
107 void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callback_t callback)
109         struct name_entry *entry = xmalloc(n*sizeof(*entry));
111         for (;;) {
112                 unsigned long mask = 0;
113                 int i, last;
115                 last = -1;
116                 for (i = 0; i < n; i++) {
117                         if (!t[i].size)
118                                 continue;
119                         entry_extract(t+i, entry+i);
120                         if (last >= 0) {
121                                 int cmp = entry_compare(entry+i, entry+last);
123                                 /*
124                                  * Is the new name bigger than the old one?
125                                  * Ignore it
126                                  */
127                                 if (cmp > 0)
128                                         continue;
129                                 /*
130                                  * Is the new name smaller than the old one?
131                                  * Ignore all old ones
132                                  */
133                                 if (cmp < 0)
134                                         mask = 0;
135                         }
136                         mask |= 1ul << i;
137                         last = i;
138                 }
139                 if (!mask)
140                         break;
142                 /*
143                  * Update the tree entries we've walked, and clear
144                  * all the unused name-entries.
145                  */
146                 for (i = 0; i < n; i++) {
147                         if (mask & (1ul << i)) {
148                                 update_tree_entry(t+i);
149                                 continue;
150                         }
151                         entry_clear(entry + i);
152                 }
153                 callback(n, mask, entry, base);
154         }
155         free(entry);
158 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
160         int namelen = strlen(name);
161         while (t->size) {
162                 const char *entry;
163                 const unsigned char *sha1;
164                 int entrylen, cmp;
166                 sha1 = tree_entry_extract(t, &entry, mode);
167                 update_tree_entry(t);
168                 entrylen = tree_entry_len(entry, sha1);
169                 if (entrylen > namelen)
170                         continue;
171                 cmp = memcmp(name, entry, entrylen);
172                 if (cmp > 0)
173                         continue;
174                 if (cmp < 0)
175                         break;
176                 if (entrylen == namelen) {
177                         hashcpy(result, sha1);
178                         return 0;
179                 }
180                 if (name[entrylen] != '/')
181                         continue;
182                 if (!S_ISDIR(*mode))
183                         break;
184                 if (++entrylen == namelen) {
185                         hashcpy(result, sha1);
186                         return 0;
187                 }
188                 return get_tree_entry(sha1, name + entrylen, result, mode);
189         }
190         return -1;
193 int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
195         int retval;
196         void *tree;
197         unsigned long size;
198         struct tree_desc t;
199         unsigned char root[20];
201         tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
202         if (!tree)
203                 return -1;
205         if (name[0] == '\0') {
206                 hashcpy(sha1, root);
207                 return 0;
208         }
210         init_tree_desc(&t, tree, size);
211         retval = find_tree_entry(&t, name, sha1, mode);
212         free(tree);
213         return retval;