mpd/src/input/BufferedInputStream.hxx
Max Kellermann 5277297336 input/buffered: move basic buffering code to class BufferingInputStream
Prepare to reuse it in another class.
2019-05-16 21:41:28 +02:00

73 lines
2.3 KiB
C++

/*
* Copyright 2003-2019 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.
*/
#ifndef MPD_BUFFERED_INPUT_STREAM_BUFFER_HXX
#define MPD_BUFFERED_INPUT_STREAM_BUFFER_HXX
#include "InputStream.hxx"
#include "BufferingInputStream.hxx"
#include <assert.h>
/**
* A "huge" buffer which remembers the (partial) contents of an
* #InputStream. This works only if the #InputStream is a "file", not
* a "stream"; see IsEligible() for details.
*/
class BufferedInputStream final : public InputStream, BufferingInputStream {
// TODO: make configurable
static constexpr offset_type MAX_SIZE = 128 * 1024 * 1024;
public:
BufferedInputStream(InputStreamPtr _input);
/**
* Check whether the given #InputStream can be used as input
* for this class.
*/
static bool IsEligible(const InputStream &input) noexcept {
assert(input.IsReady());
return input.IsSeekable() && input.KnownSize() &&
input.GetSize() > 0 &&
input.GetSize() <= MAX_SIZE;
}
/* virtual methods from class InputStream */
void Check() override;
/* we don't need to implement Update() because all attributes
have been copied already in our constructor */
//void Update() noexcept;
void Seek(std::unique_lock<Mutex> &lock, offset_type offset) override;
bool IsEOF() noexcept override;
/* we don't support tags */
// std::unique_ptr<Tag> ReadTag() override;
bool IsAvailable() noexcept override;
size_t Read(std::unique_lock<Mutex> &lock,
void *ptr, size_t size) override;
private:
/* virtual methods from class BufferingInputStream */
void OnBufferAvailable() noexcept override {
InvokeOnAvailable();
}
};
#endif