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
|
/*
* name-hash.c
*
* Hashing names in the index state
*
* Copyright (C) 2008 Linus Torvalds
*/
#define NO_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
/*
* This removes bit 5 if bit 6 is set.
*
* That will make US-ASCII characters hash to their upper-case
* equivalent. We could easily do this one whole word at a time,
* but that's for future worries.
*/
static inline unsigned char icase_hash(unsigned char c)
{
return c & ~((c & 0x40) >> 1);
}
static unsigned int hash_name(const char *name, int namelen)
{
unsigned int hash = 0x123;
while (namelen--) {
unsigned char c = *name++;
c = icase_hash(c);
hash = hash*101 + c;
}
return hash;
}
static void hash_index_entry_directories(struct index_state *istate, struct cache_entry *ce)
{
/*
* Throw each directory component in the hash for quick lookup
* during a git status. Directory components are stored with their
* closing slash. Despite submodules being a directory, they never
* reach this point, because they are stored without a closing slash
* in the cache.
*
* Note that the cache_entry stored with the directory does not
* represent the directory itself. It is a pointer to an existing
* filename, and its only purpose is to represent existence of the
* directory in the cache. It is very possible multiple directory
* hash entries may point to the same cache_entry.
*/
unsigned int hash;
void **pos;
const char *ptr = ce->name;
while (*ptr) {
while (*ptr && *ptr != '/')
++ptr;
if (*ptr == '/') {
++ptr;
hash = hash_name(ce->name, ptr - ce->name);
pos = insert_hash(hash, ce, &istate->name_hash);
if (pos) {
ce->dir_next = *pos;
*pos = ce;
}
}
}
}
static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
{
void **pos;
unsigned int hash;
if (ce->ce_flags & CE_HASHED)
return;
ce->ce_flags |= CE_HASHED;
ce->next = ce->dir_next = NULL;
hash = hash_name(ce->name, ce_namelen(ce));
pos = insert_hash(hash, ce, &istate->name_hash);
if (pos) {
ce->next = *pos;
*pos = ce;
}
if (ignore_case)
hash_index_entry_directories(istate, ce);
}
static void lazy_init_name_hash(struct index_state *istate)
{
int nr;
if (istate->name_hash_initialized)
return;
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)
{
ce->ce_flags &= ~CE_UNHASHED;
if (istate->name_hash_initialized)
hash_index_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;
/*
* If the entry we're comparing is a filename (no trailing slash), then compare
* the lengths exactly.
*/
if (name[namelen - 1] != '/')
return slow_same_name(name, namelen, ce->name, len);
/*
* For a directory, we point to an arbitrary cache_entry filename. Just
* make sure the directory portion matches.
*/
return slow_same_name(name, namelen, ce->name, namelen < len ? namelen : len);
}
struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int icase)
{
unsigned int hash = hash_name(name, namelen);
struct cache_entry *ce;
lazy_init_name_hash(istate);
ce = lookup_hash(hash, &istate->name_hash);
while (ce) {
if (!(ce->ce_flags & CE_UNHASHED)) {
if (same_name(ce, name, namelen, icase))
return ce;
}
if (icase && name[namelen - 1] == '/')
ce = ce->dir_next;
else
ce = ce->next;
}
/*
* Might be a submodule. Despite submodules being directories,
* they are stored in the name hash without a closing slash.
* When ignore_case is 1, directories are stored in the name hash
* with their closing slash.
*
* The side effect of this storage technique is we have need to
* remove the slash from name and perform the lookup again without
* the slash. If a match is made, S_ISGITLINK(ce->mode) will be
* true.
*/
if (icase && name[namelen - 1] == '/') {
ce = index_name_exists(istate, name, namelen - 1, icase);
if (ce && S_ISGITLINK(ce->ce_mode))
return ce;
}
return NULL;
}
|
