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/*
* Copyright 2003-2018 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 "Ptr.hxx"
#include "Handler.hxx"
#include "thread/Thread.hxx"
#include "thread/Cond.hxx"
#include "util/SparseBuffer.hxx"
#include <exception>
#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, InputStreamHandler {
InputStreamPtr input;
Thread thread;
/**
* This #Cond wakes up the #Thread. It is used by both the
* "client" thread (to submit commands) and #input's handler
* (to notify new data being available).
*/
Cond wake_cond;
/**
* This #Cond wakes up the client upon command completion.
*/
Cond client_cond;
SparseBuffer<uint8_t> buffer;
bool stop = false, seek = false, idle = false;
offset_type seek_offset;
std::exception_ptr read_error, seek_error;
// TODO: make configurable
static constexpr offset_type MAX_SIZE = 128 * 1024 * 1024;
public:
BufferedInputStream(InputStreamPtr _input);
~BufferedInputStream() noexcept override;
/**
* 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(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(void *ptr, size_t size) override;
/* virtual methods from class InputStreamHandler */
void OnInputStreamReady() noexcept override {
/* this should never be called, because our input must
be "ready" already */
}
void OnInputStreamAvailable() noexcept override {
wake_cond.signal();
}
private:
void RunThread() noexcept;
};
#endif
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