1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/*
* name-hash.c
*
* Hashing names in the index state
*
* Copyright (C) 2008 Linus Torvalds
*/
#define NO_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
struct dir_entry {
struct hashmap_entry ent;
struct dir_entry *parent;
struct cache_entry *ce;
int nr;
unsigned int namelen;
};
static int dir_entry_cmp(const struct dir_entry *e1,
const struct dir_entry *e2, const char *name)
{
return e1->namelen != e2->namelen || strncasecmp(e1->ce->name,
name ? name : e2->ce->name, e1->namelen);
}
static struct dir_entry *find_dir_entry(struct index_state *istate,
const char *name, unsigned int namelen)
{
struct dir_entry key;
hashmap_entry_init(&key, memihash(name, namelen));
key.namelen = namelen;
return hashmap_get(&istate->dir_hash, &key, name);
}
static struct dir_entry *hash_dir_entry(struct index_state *istate,
struct cache_entry *ce, int namelen)
{
/*
* Throw each directory component in the hash for quick lookup
* during a git status. Directory components are stored without their
* closing slash. Despite submodules being a directory, they never
* reach this point, because they are stored
* in index_state.name_hash (as ordinary cache_entries).
*
* Note that the cache_entry stored with the dir_entry merely
* supplies the name of the directory (up to dir_entry.namelen). We
* track the number of 'active' files in a directory in dir_entry.nr,
* so we can tell if the directory is still relevant, e.g. for git
* status. However, if cache_entries are removed, we cannot pinpoint
* an exact cache_entry that's still active. It is very possible that
* multiple dir_entries point to the same cache_entry.
*/
struct dir_entry *dir;
/* get length of parent directory */
while (namelen > 0 && !is_dir_sep(ce->name[namelen - 1]))
namelen--;
if (namelen <= 0)
return NULL;
namelen--;
/* lookup existing entry for that directory */
dir = find_dir_entry(istate, ce->name, namelen);
if (!dir) {
/* not found, create it and add to hash table */
dir = xcalloc(1, sizeof(struct dir_entry));
hashmap_entry_init(dir, memihash(ce->name, namelen));
dir->namelen = namelen;
dir->ce = ce;
hashmap_add(&istate->dir_hash, dir);
/* recursively add missing parent directories */
dir->parent = hash_dir_entry(istate, ce, namelen);
}
return dir;
}
static void add_dir_entry(struct index_state *istate, struct cache_entry *ce)
{
/* Add reference to the directory entry (and parents if 0). */
struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
while (dir && !(dir->nr++))
dir = dir->parent;
}
static void remove_dir_entry(struct index_state *istate, struct cache_entry *ce)
{
/*
* Release reference to the directory entry. If 0, remove and continue
* with parent directory.
*/
struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce));
while (dir && !(--dir->nr)) {
struct dir_entry *parent = dir->parent;
hashmap_remove(&istate->dir_hash, dir, NULL);
free(dir);
dir = parent;
}
}
static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
{
if (ce->ce_flags & CE_HASHED)
return;
ce->ce_flags |= CE_HASHED;
hashmap_entry_init(ce, memihash(ce->name, ce_namelen(ce)));
hashmap_add(&istate->name_hash, ce);
if (ignore_case)
add_dir_entry(istate, ce);
}
static int cache_entry_cmp(const struct cache_entry *ce1,
const struct cache_entry *ce2, const void *remove)
{
/*
* For remove_name_hash, find the exact entry (pointer equality); for
* index_file_exists, find all entries with matching hash code and
* decide whether the entry matches in same_name.
*/
return remove ? !(ce1 == ce2) : 0;
}
static void lazy_init_name_hash(struct index_state *istate)
{
int nr;
if (istate->name_hash_initialized)
return;
hashmap_init(&istate->name_hash, (hashmap_cmp_fn) cache_entry_cmp,
istate->cache_nr);
hashmap_init(&istate->dir_hash, (hashmap_cmp_fn) dir_entry_cmp, 0);
for (nr = 0; nr < istate->cache_nr; nr++)
hash_index_entry(istate, istate->cache[nr]);
istate->name_hash_initialized = 1;
}
void add_name_hash(struct index_state *istate, struct cache_entry *ce)
{
if (istate->name_hash_initialized)
hash_index_entry(istate, ce);
}
void remove_name_hash(struct index_state *istate, struct cache_entry *ce)
{
if (!istate->name_hash_initialized || !(ce->ce_flags & CE_HASHED))
return;
ce->ce_flags &= ~CE_HASHED;
hashmap_remove(&istate->name_hash, ce, ce);
if (ignore_case)
remove_dir_entry(istate, ce);
}
static int slow_same_name(const char *name1, int len1, const char *name2, int len2)
{
if (len1 != len2)
return 0;
while (len1) {
unsigned char c1 = *name1++;
unsigned char c2 = *name2++;
len1--;
if (c1 != c2) {
c1 = toupper(c1);
c2 = toupper(c2);
if (c1 != c2)
return 0;
}
}
return 1;
}
static int same_name(const struct cache_entry *ce, const char *name, int namelen, int icase)
{
int len = ce_namelen(ce);
/*
* Always do exact compare, even if we want a case-ignoring comparison;
* we do the quick exact one first, because it will be the common case.
*/
if (len == namelen && !cache_name_compare(name, namelen, ce->name, len))
return 1;
if (!icase)
return 0;
return slow_same_name(name, namelen, ce->name, len);
}
struct cache_entry *index_dir_exists(struct index_state *istate, const char *name, int namelen)
{
struct cache_entry *ce;
struct dir_entry *dir;
lazy_init_name_hash(istate);
dir = find_dir_entry(istate, name, namelen);
if (dir && dir->nr)
return dir->ce;
/*
* It might be a submodule. Unlike plain directories, which are stored
* in the dir-hash, submodules are stored in the name-hash, so check
* there, as well.
*/
ce = index_file_exists(istate, name, namelen, 1);
if (ce && S_ISGITLINK(ce->ce_mode))
return ce;
return NULL;
}
struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase)
{
struct cache_entry *ce;
struct hashmap_entry key;
lazy_init_name_hash(istate);
hashmap_entry_init(&key, memihash(name, namelen));
ce = hashmap_get(&istate->name_hash, &key, NULL);
while (ce) {
if (same_name(ce, name, namelen, icase))
return ce;
ce = hashmap_get_next(&istate->name_hash, ce);
}
return NULL;
}
void free_name_hash(struct index_state *istate)
{
if (!istate->name_hash_initialized)
return;
istate->name_hash_initialized = 0;
hashmap_free(&istate->name_hash, 0);
hashmap_free(&istate->dir_hash, 1);
}
|
