aboutsummaryrefslogtreecommitdiffstats
path: root/src/fs/io/FileReader.cxx
blob: e4198b71ac30ef2256733671dba5f21db35689b6 (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
/*
 * Copyright (C) 2003-2015 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.
 */

#include "config.h"
#include "FileReader.hxx"
#include "fs/FileSystem.hxx"
#include "util/Error.hxx"

#ifdef WIN32

FileReader::FileReader(Path _path, Error &error)
	:path(_path),
	 handle(CreateFile(path.c_str(), GENERIC_READ, FILE_SHARE_READ,
			   nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
			   nullptr))
{
	if (handle == INVALID_HANDLE_VALUE) {
		const auto path_utf8 = path.ToUTF8();
		error.FormatLastError("Failed to open %s", path_utf8.c_str());
	}
}

size_t
FileReader::Read(void *data, size_t size, Error &error)
{
	assert(IsDefined());

	DWORD nbytes;
	if (!ReadFile(handle, data, size, &nbytes, nullptr)) {
		const auto path_utf8 = path.ToUTF8();
		error.FormatLastError("Failed to read from %s",
				      path_utf8.c_str());
		nbytes = 0;
	}

	return nbytes;
}

bool
FileReader::Seek(off_t offset, Error &error)
{
	assert(IsDefined());

	auto result = SetFilePointer(handle, offset, nullptr, FILE_BEGIN);
	const bool success = result != INVALID_SET_FILE_POINTER;
	if (!success)
		error.SetLastError("Failed to seek");

	return success;
}

void
FileReader::Close()
{
	assert(IsDefined());

	CloseHandle(handle);
}

#else

#include <fcntl.h>
#include <unistd.h>
#include <errno.h>

FileReader::FileReader(Path _path, Error &error)
	:path(_path),
	 fd(OpenFile(path,
		     O_RDONLY,
		     0))
{
	if (fd < 0)
		error.FormatErrno("Failed to open %s", path.c_str());
}

size_t
FileReader::Read(void *data, size_t size, Error &error)
{
	assert(IsDefined());

	ssize_t nbytes = read(fd, data, size);
	if (nbytes < 0) {
		error.FormatErrno("Failed to read from %s", path.c_str());
		nbytes = 0;
	}

	return nbytes;
}

bool
FileReader::Seek(off_t offset, Error &error)
{
	assert(IsDefined());

	auto result = lseek(fd, offset, SEEK_SET);
	const bool success = result >= 0;
	if (!success)
		error.SetErrno("Failed to seek");

	return success;
}

void
FileReader::Close()
{
	assert(IsDefined());

	close(fd);
	fd = -1;
}

#endif