sinkbase.h

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/*
 * Copyright (C) 2006-2021  Music Technology Group - Universitat Pompeu Fabra
 *
 * This file is part of Essentia
 *
 * Essentia is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation (FSF), either version 3 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 Affero GNU General Public License
 * version 3 along with this program.  If not, see http://www.gnu.org/licenses/
 */
 
#ifndef ESSENTIA_SINKBASE_H
#define ESSENTIA_SINKBASE_H
 
#include "../types.h"
#include "../connector.h"
 
namespace essentia {
namespace streaming {
 
class SinkBase;
class SinkProxyBase;
class SourceBase;
class Algorithm;
 
 
void connect(SourceBase& source, SinkBase& sink);
void disconnect(SourceBase& source, SinkBase& sink);
 
void attach(SinkProxyBase& proxy, SinkBase& innerSink);
void detach(SinkProxyBase& proxy, SinkBase& innerSink);
 
 
class SinkBase : public Connector {
 protected:
  SourceBase* _source;
  ReaderID _id; // ID to use to identify this reader for the source (to know which reader is requesting tokens, etc...)
 
  SinkProxyBase* _sproxy;
 
 public:
  SinkBase(Algorithm* parent = 0, const std::string& name = "unnamed") :
    Connector(parent, name), _source(0), _sproxy(0) {}
 
  SinkBase(const std::string& name) :
    Connector(name), _source(0), _sproxy(0) {}
 
  ~SinkBase() {
    // NB: this call needs to come before the next one because _source is set by the proxy
    //     even though we're not explicitly connected to a source ourselves
    E_DEBUG(EMemory, "Deleting SinkBase " << fullName());
    if (_sproxy) essentia::streaming::detach(*_sproxy, *this);
    if (_source) essentia::streaming::disconnect(*_source, *this);
    E_DEBUG(EMemory, "Deleting SinkBase " << fullName() << "ok!");
  }
 
  const SourceBase* source() const { return _source; }
  SourceBase* source() { return _source; }
  virtual void setSource(SourceBase* source);
 
  ReaderID id() const;
  virtual void setId(ReaderID id);
 
  // should return a vector<TokenType>*
  virtual const void* getTokens() const = 0;
 
  // should return a TokenType*
  virtual const void* getFirstToken() const = 0;
 
 protected:
  // methods for standard connections
 
  // made those protected so that only our friend streaming::{dis}connect() functions can access these
  virtual void connect(SourceBase& source);
  virtual void disconnect(SourceBase& source);
 
  friend void connect(SourceBase& source, SinkBase& sink);
  friend void disconnect(SourceBase& source, SinkBase& sink);
 
 
  // methods for proxies
 
  friend void attach(SinkProxyBase& proxy, SinkBase& innerSink);
  friend void detach(SinkProxyBase& proxy, SinkBase& innerSink);
 
  // Note: these can't be called attach because they would be shadowed by SourceProxyBase::attach(SourceBase)
  void attachProxy(SinkProxyBase* sproxy);
  void detachProxy(SinkProxyBase* sproxy);
 
  // for SourceBase destructor
  friend class SourceBase;
 
};
 
} // namespace streaming
} // namespace essentia
 
#endif // ESSENTIA_SINKBASE_H