aboutsummaryrefslogtreecommitdiffstats
path: root/src/FileSystem.hxx
blob: cf0fe4bbf7a1ee960d034adbb2378031d9036411 (plain) (blame)
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
/*
 * Copyright (C) 2003-2013 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef MPD_FILESYSTEM_HXX
#define MPD_FILESYSTEM_HXX

#include "check.h"
#include "fd_util.h"

#include "Path.hxx"

#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <assert.h>
#include <stdio.h>

namespace FOpenMode {
/**
 * Open mode for reading text files.
 */
constexpr Path::const_pointer ReadText = "r";

/**
 * Open mode for reading binary files.
 */
constexpr Path::const_pointer ReadBinary = "rb";

/**
 * Open mode for writing text files.
 */
constexpr Path::const_pointer WriteText = "w";

/**
 * Open mode for writing binary files.
 */
constexpr Path::const_pointer WriteBinary = "wb";
}

/**
 * Wrapper for fopen() that uses #Path names.
 */
static inline FILE *FOpen(const Path &file, Path::const_pointer mode)
{
	return fopen(file.c_str(), mode);
}

/**
 * Wrapper for open_cloexec() that uses #Path names.
 */
static inline int OpenFile(const Path &file, int flags, int mode)
{
	return open_cloexec(file.c_str(), flags, mode);
}

/**
 * Wrapper for rename() that uses #Path names.
 */
static inline int RenameFile(const Path &oldpath, const Path &newpath)
{
	return rename(oldpath.c_str(), newpath.c_str());
}

/**
 * Wrapper for stat() that uses #Path names.
 */
static inline int StatFile(const Path &file, struct stat &buf)
{
	return stat(file.c_str(), &buf);
}

/**
 * Wrapper for unlink() that uses #Path names.
 */
static inline int UnlinkFile(const Path &file)
{
	return unlink(file.c_str());
}

/**
 * Wrapper for readlink() that uses #Path names.
 * Unlike readlink() it returns true on success and false otherwise.
 * Use errno to get error code.
 */
bool ReadLink(const Path &path, Path &result);

/**
 * Wrapper for access() that uses #Path names.
 */
static inline int CheckAccess(const Path &path, int mode)
{
#ifdef WIN32
	(void)path;
	(void)mode;
	return 0;
#else
	return access(path.c_str(), mode);
#endif
}

/**
 * Checks if #Path is a regular file.
 */
static inline bool CheckIsRegular(const Path &path)
{
	struct stat buf;
	return StatFile(path, buf) == 0 && S_ISREG(buf.st_mode);
}

/**
 * Checks if #Path is a directory.
 */
static inline bool CheckIsDirectory(const Path &path)
{
	struct stat buf;
	return StatFile(path, buf) == 0 && S_ISDIR(buf.st_mode);
}

/**
 * Checks if #Path exists.
 */
static inline bool CheckExists(const Path &path)
{
	struct stat buf;
	return StatFile(path, buf) == 0;
}

/**
 * Reader for directory entries.
 */
class DirectoryReader {
	DIR *const dirp;
	dirent *ent;
public:
	/**
	 * Creates new directory reader for the specified #dir.
	 */
	explicit DirectoryReader(const Path &dir)
		: dirp(opendir(dir.c_str())),
		  ent(nullptr) {
	}

	DirectoryReader(const DirectoryReader &other) = delete;
	DirectoryReader &operator=(const DirectoryReader &other) = delete;

	/**
	 * Destroys this instance.
	 */
	~DirectoryReader() {
		if (!Failed())
			closedir(dirp);
	}

	/**
	 * Checks if directory failed to open. 
	 */
	bool Failed() const {
		return dirp == nullptr;
	}

	/**
	 * Checks if directory entry is available.
	 */
	bool HasEntry() const {
		assert(!Failed());
		return ent != nullptr;
	}

	/**
	 * Reads next directory entry.
	 */
	bool ReadEntry() {
		assert(!Failed());
		ent = readdir(dirp);
		return HasEntry();
	}

	/**
	 * Extracts directory entry that was previously read by #ReadEntry.
	 */
	Path GetEntry() const {
		assert(HasEntry());
		return Path::FromFS(ent->d_name);
	}
};

#endif