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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_PROXY_INPUT_STREAM_HXX
#define MPD_PROXY_INPUT_STREAM_HXX
#include "InputStream.hxx"
#include "Ptr.hxx"
#include "Handler.hxx"
#include "thread/Cond.hxx"
struct Tag;
/**
* An #InputStream that forwards all methods call to another
* #InputStream instance. This can be used as a base class to
* override selected methods.
*
* The inner #InputStream instance may be nullptr initially, to be set
* later.
*/
class ProxyInputStream : public InputStream, protected InputStreamHandler {
Cond set_input_cond;
protected:
InputStreamPtr input;
public:
explicit ProxyInputStream(InputStreamPtr _input) noexcept;
/**
* Construct an instance without an #InputStream instance.
* Once that instance becomes available, call SetInput().
*/
ProxyInputStream(const char *_uri,
Mutex &_mutex) noexcept
:InputStream(_uri, _mutex) {}
virtual ~ProxyInputStream() noexcept;
ProxyInputStream(const ProxyInputStream &) = delete;
ProxyInputStream &operator=(const ProxyInputStream &) = delete;
/* virtual methods from InputStream */
void Check() override;
void Update() noexcept override;
void Seek(offset_type new_offset) override;
bool IsEOF() noexcept override;
std::unique_ptr<Tag> ReadTag() override;
bool IsAvailable() noexcept override;
size_t Read(void *ptr, size_t read_size) override;
protected:
/**
* If this instance was initialized without an input, this
* method can set it.
*
* Caller must lock the mutex.
*/
void SetInput(InputStreamPtr _input) noexcept;
/**
* Copy public attributes from the underlying input stream to the
* "rewind" input stream. This function is called when a method of
* the underlying stream has returned, which may have modified these
* attributes.
*/
void CopyAttributes();
/* virtual methods from class InputStreamHandler */
void OnInputStreamReady() noexcept override {
InvokeOnReady();
}
void OnInputStreamAvailable() noexcept override {
InvokeOnAvailable();
}
};
#endif
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