mpd/src/io/FileReader.hxx
2023-10-07 12:48:03 +02:00

103 lines
1.8 KiB
C++

// SPDX-License-Identifier: BSD-2-Clause
// author: Max Kellermann <max.kellermann@gmail.com>
#pragma once
#include "Reader.hxx"
#ifdef _WIN32
#include <fileapi.h>
#include <handleapi.h> // for INVALID_HANDLE_VALUE
#include <windef.h> // for HWND (needed by winbase.h)
#include <winbase.h> // for FILE_CURRENT
#else
#include "io/UniqueFileDescriptor.hxx"
#endif
#include <cstdint>
#include <utility> // for std::exchange()
#include <sys/types.h> // for off_t
class Path;
class FileInfo;
class FileReader final : public Reader {
#ifdef _WIN32
HANDLE handle;
#else
UniqueFileDescriptor fd;
#endif
public:
explicit FileReader(Path _path);
#ifdef _WIN32
FileReader(FileReader &&other) noexcept
:handle(std::exchange(other.handle, INVALID_HANDLE_VALUE)) {}
~FileReader() noexcept {
if (handle != INVALID_HANDLE_VALUE)
CloseHandle(handle);
}
#else
FileReader(FileReader &&other) noexcept
:fd(std::move(other.fd)) {}
#endif
protected:
bool IsDefined() const noexcept {
#ifdef _WIN32
return handle != INVALID_HANDLE_VALUE;
#else
return fd.IsDefined();
#endif
}
public:
#ifndef _WIN32
FileDescriptor GetFD() const noexcept {
return fd;
}
#endif
FileInfo GetFileInfo() const;
[[gnu::pure]]
uint_least64_t GetSize() const noexcept {
#ifdef _WIN32
LARGE_INTEGER size;
return GetFileSizeEx(handle, &size)
? size.QuadPart
: 0;
#else
return fd.GetSize();
#endif
}
[[gnu::pure]]
uint_least64_t GetPosition() const noexcept {
#ifdef _WIN32
LARGE_INTEGER zero;
zero.QuadPart = 0;
LARGE_INTEGER position;
return SetFilePointerEx(handle, zero, &position, FILE_CURRENT)
? position.QuadPart
: 0;
#else
return fd.Tell();
#endif
}
void Rewind() {
Seek(0);
}
void Seek(off_t offset);
void Skip(off_t offset);
/* virtual methods from class Reader */
std::size_t Read(std::span<std::byte> dest) override;
};