sourcebase.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_SOURCEBASE_H
#define ESSENTIA_SOURCEBASE_H
 
#include "../types.h"
#include "../connector.h"
 
namespace essentia {
namespace streaming {
 
class SourceBase;
class SourceProxyBase;
  //template <typename T> class SourceProxy;
class SinkBase;
class Algorithm;
 
void connect(SourceBase& source, SinkBase& sink);
void disconnect(SourceBase& source, SinkBase& sink);
 
void attach(SourceBase& innerSource, SourceProxyBase& proxy);
void detach(SourceBase& innerSource, SourceProxyBase& proxy);
 
 
class SourceBase : public Connector {
 protected:
  std::vector<SinkBase*> _sinks;
 
  // we only allow for 1 proxy to be connected at the moment
  // (although multiple ones would be theoretically correct, too)
  SourceProxyBase* _sproxy;
 
 public:
  // TODO: are those still useful?
  SourceBase(Algorithm* parent = 0, const std::string& name = "unnamed") :
    Connector(parent, name), _sproxy(0) {}
 
  SourceBase(const std::string& name) :
    Connector(name), _sproxy(0) {}
 
  ~SourceBase();
 
  // this function should probably be protected, with friend = SinkBase, Sink
  virtual void* buffer() = 0;
 
  virtual int totalProduced() const = 0;
 
  const std::vector<SinkBase*>& sinks() const { return _sinks; }
 
  // TODO: remove me to avoid people doing stuff like src.sinks().clear()
  std::vector<SinkBase*>& sinks() { return _sinks; }
 
  // should return a vector<TokenType>*
  virtual void* getTokens() = 0;
 
  // should return a TokenType*
  virtual void* getFirstToken() = 0;
 
  bool isProxied() const { return _sproxy != 0; }
 
  const std::vector<SinkBase*>& proxiedSinks() const;
 
  template <typename TokenType>
  void push(const TokenType& value) {
    try {
      checkType<TokenType>();
      if (!acquire(1))
        throw EssentiaException(fullName(), ": Could not push 1 value, output buffer is full");
 
      *(TokenType*)getFirstToken() = value;
 
      release(1);
    }
    catch (EssentiaException& e) {
      throw EssentiaException("While trying to push item into source ", fullName(), ":\n", e.what());
    }
  }
 
  // function to resize the buffer given the type of tokens we want to convey
  virtual void setBufferType(BufferUsage::BufferUsageType type) = 0;
 
  virtual BufferInfo bufferInfo() const = 0;
  virtual void setBufferInfo(const BufferInfo& info) = 0;
 
 protected:
  // made those protected so that only our friend streaming::{dis}connect() functions can access these
  // @todo this function should probably be protected by a mutex (?)
  virtual void connect(SinkBase& sink);
  virtual void disconnect(SinkBase& sink);
 
  friend void connect(SourceBase& source, SinkBase& sink);
  friend void disconnect(SourceBase& source, SinkBase& sink);
 
 
  virtual ReaderID addReader() = 0;
  virtual void removeReader(ReaderID id) = 0;
 
 
  friend void attach(SourceBase& innerSource, SourceProxyBase& proxy);
  friend void detach(SourceBase& innerSource, SourceProxyBase& proxy);
 
  // Note: these can't be called attach because they would be shadowed by SourceProxyBase::attach(SourceBase)
  void attachProxy(SourceProxyBase* sproxy);
  void detachProxy(SourceProxyBase* sproxy);
 
  friend class SourceProxyBase;
  // TODO: still needed?
  template <typename T> friend class SourceProxy;
  template <typename T> friend class SinkProxy;
 
};
 
} // namespace streaming
} // namespace essentia
 
#endif // ESSENTIA_SOURCEBASE_H