Merge branch 'ew/rebase'
[git/git.git] / tree-walk.c
1 #include "cache.h"
2 #include "tree-walk.h"
3 #include "tree.h"
4
5 void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
6 {
7 unsigned long size = 0;
8 void *buf = NULL;
9
10 if (sha1) {
11 buf = read_object_with_reference(sha1, tree_type, &size, NULL);
12 if (!buf)
13 die("unable to read tree %s", sha1_to_hex(sha1));
14 }
15 desc->size = size;
16 desc->buf = buf;
17 return buf;
18 }
19
20 static int entry_compare(struct name_entry *a, struct name_entry *b)
21 {
22 return base_name_compare(
23 a->path, a->pathlen, a->mode,
24 b->path, b->pathlen, b->mode);
25 }
26
27 static void entry_clear(struct name_entry *a)
28 {
29 memset(a, 0, sizeof(*a));
30 }
31
32 static void entry_extract(struct tree_desc *t, struct name_entry *a)
33 {
34 a->sha1 = tree_entry_extract(t, &a->path, &a->mode);
35 a->pathlen = strlen(a->path);
36 }
37
38 void update_tree_entry(struct tree_desc *desc)
39 {
40 const void *buf = desc->buf;
41 unsigned long size = desc->size;
42 int len = strlen(buf) + 1 + 20;
43
44 if (size < len)
45 die("corrupt tree file");
46 desc->buf = (char *) buf + len;
47 desc->size = size - len;
48 }
49
50 static const char *get_mode(const char *str, unsigned int *modep)
51 {
52 unsigned char c;
53 unsigned int mode = 0;
54
55 while ((c = *str++) != ' ') {
56 if (c < '0' || c > '7')
57 return NULL;
58 mode = (mode << 3) + (c - '0');
59 }
60 *modep = mode;
61 return str;
62 }
63
64 const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
65 {
66 const void *tree = desc->buf;
67 unsigned long size = desc->size;
68 int len = strlen(tree)+1;
69 const unsigned char *sha1 = (unsigned char *) tree + len;
70 const char *path;
71 unsigned int mode;
72
73 path = get_mode(tree, &mode);
74 if (!path || size < len + 20)
75 die("corrupt tree file");
76 *pathp = path;
77 *modep = canon_mode(mode);
78 return sha1;
79 }
80
81 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
82 {
83 const void *tree = desc->buf;
84 const char *path;
85 unsigned long len, size = desc->size;
86
87 if (!size)
88 return 0;
89
90 path = get_mode(tree, &entry->mode);
91 if (!path)
92 die("corrupt tree file");
93
94 entry->path = path;
95 len = strlen(path);
96 entry->pathlen = len;
97
98 path += len + 1;
99 entry->sha1 = (const unsigned char *) path;
100
101 path += 20;
102 len = path - (char *) tree;
103 if (len > size)
104 die("corrupt tree file");
105
106 desc->buf = path;
107 desc->size = size - len;
108 return 1;
109 }
110
111 void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callback_t callback)
112 {
113 struct name_entry *entry = xmalloc(n*sizeof(*entry));
114
115 for (;;) {
116 struct name_entry entry[3];
117 unsigned long mask = 0;
118 int i, last;
119
120 last = -1;
121 for (i = 0; i < n; i++) {
122 if (!t[i].size)
123 continue;
124 entry_extract(t+i, entry+i);
125 if (last >= 0) {
126 int cmp = entry_compare(entry+i, entry+last);
127
128 /*
129 * Is the new name bigger than the old one?
130 * Ignore it
131 */
132 if (cmp > 0)
133 continue;
134 /*
135 * Is the new name smaller than the old one?
136 * Ignore all old ones
137 */
138 if (cmp < 0)
139 mask = 0;
140 }
141 mask |= 1ul << i;
142 last = i;
143 }
144 if (!mask)
145 break;
146
147 /*
148 * Update the tree entries we've walked, and clear
149 * all the unused name-entries.
150 */
151 for (i = 0; i < n; i++) {
152 if (mask & (1ul << i)) {
153 update_tree_entry(t+i);
154 continue;
155 }
156 entry_clear(entry + i);
157 }
158 callback(n, mask, entry, base);
159 }
160 free(entry);
161 }
162
163 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
164 {
165 int namelen = strlen(name);
166 while (t->size) {
167 const char *entry;
168 const unsigned char *sha1;
169 int entrylen, cmp;
170
171 sha1 = tree_entry_extract(t, &entry, mode);
172 update_tree_entry(t);
173 entrylen = strlen(entry);
174 if (entrylen > namelen)
175 continue;
176 cmp = memcmp(name, entry, entrylen);
177 if (cmp > 0)
178 continue;
179 if (cmp < 0)
180 break;
181 if (entrylen == namelen) {
182 memcpy(result, sha1, 20);
183 return 0;
184 }
185 if (name[entrylen] != '/')
186 continue;
187 if (!S_ISDIR(*mode))
188 break;
189 if (++entrylen == namelen) {
190 memcpy(result, sha1, 20);
191 return 0;
192 }
193 return get_tree_entry(sha1, name + entrylen, result, mode);
194 }
195 return -1;
196 }
197
198 int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
199 {
200 int retval;
201 void *tree;
202 struct tree_desc t;
203
204 tree = read_object_with_reference(tree_sha1, tree_type, &t.size, NULL);
205 if (!tree)
206 return -1;
207 t.buf = tree;
208 retval = find_tree_entry(&t, name, sha1, mode);
209 free(tree);
210 return retval;
211 }
212