aboutsummaryrefslogtreecommitdiffstats
path: root/src/input/plugins/FileInputPlugin.cxx
blob: 867b5722d9c563f1e84d61b788cfc63da21a69e9 (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
/*
 * Copyright (C) 2003-2014 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" /* must be first for large file support */
#include "FileInputPlugin.hxx"
#include "../InputStream.hxx"
#include "../InputPlugin.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"
#include "fs/FileSystem.hxx"
#include "fs/Path.hxx"
#include "system/fd_util.h"
#include "open.h"

#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>

static constexpr Domain file_domain("file");

class FileInputStream final : public InputStream {
	const int fd;

public:
	FileInputStream(const char *path, int _fd, off_t _size,
			Mutex &_mutex, Cond &_cond)
		:InputStream(path, _mutex, _cond),
		 fd(_fd) {
		size = _size;
		seekable = true;
		SetReady();
	}

	~FileInputStream() {
		close(fd);
	}

	/* virtual methods from InputStream */

	bool IsEOF() override {
		return GetOffset() >= GetSize();
	}

	size_t Read(void *ptr, size_t size, Error &error) override;
	bool Seek(offset_type offset, Error &error) override;
};

InputStream *
OpenFileInputStream(Path path,
		    Mutex &mutex, Cond &cond,
		    Error &error)
{
	const int fd = OpenFile(path, O_RDONLY|O_BINARY, 0);
	if (fd < 0) {
		error.FormatErrno("Failed to open \"%s\"",
				  path.c_str());
		return nullptr;
	}

	struct stat st;
	if (fstat(fd, &st) < 0) {
		error.FormatErrno("Failed to stat \"%s\"", path.c_str());
		close(fd);
		return nullptr;
	}

	if (!S_ISREG(st.st_mode)) {
		error.Format(file_domain, "Not a regular file: %s",
			     path.c_str());
		close(fd);
		return nullptr;
	}

#ifdef POSIX_FADV_SEQUENTIAL
	posix_fadvise(fd, (off_t)0, st.st_size, POSIX_FADV_SEQUENTIAL);
#endif

	return new FileInputStream(path.c_str(), fd, st.st_size, mutex, cond);
}

static InputStream *
input_file_open(gcc_unused const char *filename,
		gcc_unused Mutex &mutex, gcc_unused Cond &cond,
		gcc_unused Error &error)
{
	/* dummy method; use OpenFileInputStream() instead */

	return nullptr;
}

bool
FileInputStream::Seek(offset_type new_offset, Error &error)
{
	auto result = lseek(fd, (off_t)new_offset, SEEK_SET);
	if (result < 0) {
		error.SetErrno("Failed to seek");
		return false;
	}

	offset = (offset_type)result;
	return true;
}

size_t
FileInputStream::Read(void *ptr, size_t read_size, Error &error)
{
	ssize_t nbytes = read(fd, ptr, read_size);
	if (nbytes < 0) {
		error.SetErrno("Failed to read");
		return 0;
	}

	offset += nbytes;
	return (size_t)nbytes;
}

const InputPlugin input_plugin_file = {
	"file",
	nullptr,
	nullptr,
	input_file_open,
};