Make 'traverse_tree()' use linked structure rather than 'const char *base'
[git/git.git] / tree-walk.c
CommitLineData
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1#include "cache.h"
2#include "tree-walk.h"
8e440259 3#include "tree.h"
1b0c7174 4
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5static const char *get_mode(const char *str, unsigned int *modep)
6{
7 unsigned char c;
8 unsigned int mode = 0;
9
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10 if (*str == ' ')
11 return NULL;
12
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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}
21
64cc1c09 22static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size)
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23{
24 const char *path;
25 unsigned int mode, len;
26
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27 if (size < 24 || buf[size - 21])
28 die("corrupt tree file");
29
4651ece8 30 path = get_mode(buf, &mode);
64cc1c09 31 if (!path || !*path)
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32 die("corrupt tree file");
33 len = strlen(path) + 1;
34
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}
40
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41void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
42{
43 desc->buffer = buffer;
44 desc->size = size;
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45 if (size)
46 decode_tree_entry(desc, buffer, size);
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47}
48
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49void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
50{
51 unsigned long size = 0;
52 void *buf = NULL;
53
54 if (sha1) {
8e440259 55 buf = read_object_with_reference(sha1, tree_type, &size, NULL);
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56 if (!buf)
57 die("unable to read tree %s", sha1_to_hex(sha1));
58 }
6fda5e51 59 init_tree_desc(desc, buf, size);
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60 return buf;
61}
62
63static int entry_compare(struct name_entry *a, struct name_entry *b)
64{
65 return base_name_compare(
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66 a->path, tree_entry_len(a->path, a->sha1), a->mode,
67 b->path, tree_entry_len(b->path, b->sha1), b->mode);
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68}
69
70static void entry_clear(struct name_entry *a)
71{
72 memset(a, 0, sizeof(*a));
73}
74
75static void entry_extract(struct tree_desc *t, struct name_entry *a)
76{
4651ece8 77 *a = t->entry;
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78}
79
80void update_tree_entry(struct tree_desc *desc)
81{
6fda5e51 82 const void *buf = desc->buffer;
4651ece8 83 const unsigned char *end = desc->entry.sha1 + 20;
1b0c7174 84 unsigned long size = desc->size;
4651ece8 85 unsigned long len = end - (const unsigned char *)buf;
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86
87 if (size < len)
88 die("corrupt tree file");
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89 buf = end;
90 size -= len;
91 desc->buffer = buf;
92 desc->size = size;
93 if (size)
94 decode_tree_entry(desc, buf, size);
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95}
96
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97int tree_entry(struct tree_desc *desc, struct name_entry *entry)
98{
4651ece8 99 if (!desc->size)
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100 return 0;
101
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102 *entry = desc->entry;
103 update_tree_entry(desc);
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104 return 1;
105}
106
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107void setup_traverse_info(struct traverse_info *info, const char *base)
108{
109 int pathlen = strlen(base);
110
111 memset(info, 0, sizeof(*info));
112 if (pathlen && base[pathlen-1] == '/')
113 pathlen--;
114 info->pathlen = pathlen ? pathlen + 1 : 0;
115 info->name.path = base;
116 info->name.sha1 = (void *)(base + pathlen + 1);
117}
118
119char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
120{
121 int len = tree_entry_len(n->path, n->sha1);
122 int pathlen = info->pathlen;
123
124 path[pathlen + len] = 0;
125 for (;;) {
126 memcpy(path + pathlen, n->path, len);
127 if (!pathlen)
128 break;
129 path[--pathlen] = '/';
130 n = &info->name;
131 len = tree_entry_len(n->path, n->sha1);
132 info = info->prev;
133 pathlen -= len;
134 }
135 return path;
136}
137
138void traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
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139{
140 struct name_entry *entry = xmalloc(n*sizeof(*entry));
141
142 for (;;) {
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143 unsigned long mask = 0;
144 int i, last;
145
146 last = -1;
147 for (i = 0; i < n; i++) {
148 if (!t[i].size)
149 continue;
150 entry_extract(t+i, entry+i);
151 if (last >= 0) {
152 int cmp = entry_compare(entry+i, entry+last);
153
154 /*
155 * Is the new name bigger than the old one?
156 * Ignore it
157 */
158 if (cmp > 0)
159 continue;
160 /*
161 * Is the new name smaller than the old one?
162 * Ignore all old ones
163 */
164 if (cmp < 0)
165 mask = 0;
166 }
167 mask |= 1ul << i;
168 last = i;
169 }
170 if (!mask)
171 break;
172
173 /*
174 * Update the tree entries we've walked, and clear
175 * all the unused name-entries.
176 */
177 for (i = 0; i < n; i++) {
178 if (mask & (1ul << i)) {
179 update_tree_entry(t+i);
180 continue;
181 }
182 entry_clear(entry + i);
183 }
40d934df 184 info->fn(n, mask, entry, info);
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185 }
186 free(entry);
187}
188
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189static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
190{
191 int namelen = strlen(name);
192 while (t->size) {
193 const char *entry;
194 const unsigned char *sha1;
195 int entrylen, cmp;
196
197 sha1 = tree_entry_extract(t, &entry, mode);
198 update_tree_entry(t);
304de2d2 199 entrylen = tree_entry_len(entry, sha1);
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200 if (entrylen > namelen)
201 continue;
202 cmp = memcmp(name, entry, entrylen);
203 if (cmp > 0)
204 continue;
205 if (cmp < 0)
206 break;
207 if (entrylen == namelen) {
e702496e 208 hashcpy(result, sha1);
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209 return 0;
210 }
211 if (name[entrylen] != '/')
212 continue;
213 if (!S_ISDIR(*mode))
214 break;
215 if (++entrylen == namelen) {
e702496e 216 hashcpy(result, sha1);
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217 return 0;
218 }
219 return get_tree_entry(sha1, name + entrylen, result, mode);
220 }
221 return -1;
222}
223
224int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
225{
226 int retval;
227 void *tree;
6fda5e51 228 unsigned long size;
4dcff634 229 struct tree_desc t;
d93b7d1c 230 unsigned char root[20];
4dcff634 231
6fda5e51 232 tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
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233 if (!tree)
234 return -1;
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235
236 if (name[0] == '\0') {
237 hashcpy(sha1, root);
238 return 0;
239 }
240
6fda5e51 241 init_tree_desc(&t, tree, size);
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242 retval = find_tree_entry(&t, name, sha1, mode);
243 free(tree);
244 return retval;
245}