mpd/src/input/plugins/FileInputPlugin.cxx
2023-03-06 14:59:48 +01:00

92 lines
2.0 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#include "FileInputPlugin.hxx"
#include "../InputStream.hxx"
#include "fs/Path.hxx"
#include "fs/FileInfo.hxx"
#include "lib/fmt/PathFormatter.hxx"
#include "lib/fmt/RuntimeError.hxx"
#include "io/FileReader.hxx"
#include "io/FileDescriptor.hxx"
#include <sys/stat.h>
#include <fcntl.h>
class FileInputStream final : public InputStream {
FileReader reader;
public:
FileInputStream(const char *path, FileReader &&_reader, off_t _size,
Mutex &_mutex)
:InputStream(path, _mutex),
reader(std::move(_reader)) {
size = _size;
seekable = true;
SetReady();
}
/* virtual methods from InputStream */
[[nodiscard]] bool IsEOF() const noexcept override {
return GetOffset() >= GetSize();
}
size_t Read(std::unique_lock<Mutex> &lock,
void *ptr, size_t size) override;
void Seek(std::unique_lock<Mutex> &lock,
offset_type offset) override;
};
InputStreamPtr
OpenFileInputStream(Path path, Mutex &mutex)
{
FileReader reader(path);
const FileInfo info = reader.GetFileInfo();
if (!info.IsRegular())
throw FmtRuntimeError("Not a regular file: {}", path);
#ifdef POSIX_FADV_SEQUENTIAL
posix_fadvise(reader.GetFD().Get(), (off_t)0, info.GetSize(),
POSIX_FADV_SEQUENTIAL);
#endif
return std::make_unique<FileInputStream>(path.ToUTF8Throw().c_str(),
std::move(reader), info.GetSize(),
mutex);
}
void
FileInputStream::Seek(std::unique_lock<Mutex> &,
offset_type new_offset)
{
{
const ScopeUnlock unlock(mutex);
reader.Seek((off_t)new_offset);
}
offset = new_offset;
}
size_t
FileInputStream::Read(std::unique_lock<Mutex> &,
void *ptr, size_t read_size)
{
size_t nbytes;
{
const ScopeUnlock unlock(mutex);
nbytes = reader.Read(ptr, read_size);
}
if (nbytes == 0 && !IsEOF())
throw FmtRuntimeError("Unexpected end of file {}"
" at {} of {}",
GetURI(), GetOffset(), GetSize());
offset += nbytes;
return nbytes;
}