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
|
/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <malloc.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "private/ErrnoRestorer.h"
#include "private/ScopedPthreadMutexLocker.h"
extern "C" int __getdents64(unsigned int, dirent*, unsigned int);
struct DIR {
int fd_;
size_t available_bytes_;
dirent* next_;
long current_pos_;
pthread_mutex_t mutex_;
dirent buff_[15];
};
static DIR* __allocate_DIR(int fd) {
DIR* d = reinterpret_cast<DIR*>(malloc(sizeof(DIR)));
if (d == NULL) {
return NULL;
}
d->fd_ = fd;
d->available_bytes_ = 0;
d->next_ = NULL;
d->current_pos_ = 0L;
pthread_mutex_init(&d->mutex_, NULL);
return d;
}
int dirfd(DIR* dirp) {
return dirp->fd_;
}
DIR* fdopendir(int fd) {
// Is 'fd' actually a directory?
struct stat sb;
if (fstat(fd, &sb) == -1) {
return NULL;
}
if (!S_ISDIR(sb.st_mode)) {
errno = ENOTDIR;
return NULL;
}
return __allocate_DIR(fd);
}
DIR* opendir(const char* path) {
int fd = open(path, O_CLOEXEC | O_DIRECTORY | O_RDONLY);
return (fd != -1) ? __allocate_DIR(fd) : NULL;
}
static bool __fill_DIR(DIR* d) {
int rc = TEMP_FAILURE_RETRY(__getdents64(d->fd_, d->buff_, sizeof(d->buff_)));
if (rc <= 0) {
return false;
}
d->available_bytes_ = rc;
d->next_ = d->buff_;
return true;
}
static dirent* __readdir_locked(DIR* d) {
if (d->available_bytes_ == 0 && !__fill_DIR(d)) {
return NULL;
}
dirent* entry = d->next_;
d->next_ = reinterpret_cast<dirent*>(reinterpret_cast<char*>(entry) + entry->d_reclen);
d->available_bytes_ -= entry->d_reclen;
// The directory entry offset uses 0, 1, 2 instead of real file offset,
// so the value range of long type is enough.
d->current_pos_ = static_cast<long>(entry->d_off);
return entry;
}
dirent* readdir(DIR* d) {
ScopedPthreadMutexLocker locker(&d->mutex_);
return __readdir_locked(d);
}
__strong_alias(readdir64, readdir);
int readdir_r(DIR* d, dirent* entry, dirent** result) {
ErrnoRestorer errno_restorer;
*result = NULL;
errno = 0;
ScopedPthreadMutexLocker locker(&d->mutex_);
dirent* next = __readdir_locked(d);
if (errno != 0 && next == NULL) {
return errno;
}
if (next != NULL) {
memcpy(entry, next, next->d_reclen);
*result = entry;
}
return 0;
}
__strong_alias(readdir64_r, readdir_r);
int closedir(DIR* d) {
if (d == NULL) {
errno = EINVAL;
return -1;
}
int fd = d->fd_;
pthread_mutex_destroy(&d->mutex_);
free(d);
return close(fd);
}
void rewinddir(DIR* d) {
ScopedPthreadMutexLocker locker(&d->mutex_);
lseek(d->fd_, 0, SEEK_SET);
d->available_bytes_ = 0;
d->current_pos_ = 0L;
}
void seekdir(DIR* d, long offset) {
ScopedPthreadMutexLocker locker(&d->mutex_);
off_t ret = lseek(d->fd_, offset, SEEK_SET);
if (ret != -1L) {
d->available_bytes_ = 0;
d->current_pos_ = ret;
}
}
long telldir(DIR* d) {
return d->current_pos_;
}
int alphasort(const dirent** a, const dirent** b) {
return strcoll((*a)->d_name, (*b)->d_name);
}
__strong_alias(alphasort64, alphasort);
|
