mpd/src/io/FileReader.hxx
2021-12-08 19:40:22 +01:00

134 lines
3.1 KiB
C++

/*
* Copyright 2014-2021 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef FILE_READER_HXX
#define FILE_READER_HXX
#include "Reader.hxx"
#include "fs/AllocatedPath.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
class Path;
class FileInfo;
class FileReader final : public Reader {
AllocatedPath path;
#ifdef _WIN32
HANDLE handle;
#else
UniqueFileDescriptor fd;
#endif
public:
explicit FileReader(Path _path);
#ifdef _WIN32
FileReader(FileReader &&other) noexcept
:path(std::move(other.path)),
handle(std::exchange(other.handle, INVALID_HANDLE_VALUE)) {}
~FileReader() noexcept {
if (IsDefined())
Close();
}
#else
FileReader(FileReader &&other) noexcept
:path(std::move(other.path)),
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
void Close() noexcept;
FileInfo GetFileInfo() const;
[[gnu::pure]]
uint64_t GetSize() const noexcept {
#ifdef _WIN32
LARGE_INTEGER size;
return GetFileSizeEx(handle, &size)
? size.QuadPart
: 0;
#else
return fd.GetSize();
#endif
}
[[gnu::pure]]
uint64_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(void *data, std::size_t size) override;
};
#endif