IFilter.h

/**
 * Atom-IT - A Lightweight, RESTful microservice for IoT
 * Copyright (C) 2017 Sebastien Jodogne, WSL S.A., Belgium
 *
 * 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 3 of the
 * License, or (at your option) any later version.
 *
 * In addition, as a special exception, the copyright holders of this
 * program give permission to link the code of its release with the
 * OpenSSL project's "OpenSSL" library (or with modified versions of it
 * that use the same license as the "OpenSSL" library), and distribute
 * the linked executables. You must obey the GNU General Public License
 * in all respects for all of the code used other than "OpenSSL". If you
 * modify file(s) with this exception, you may extend this exception to
 * your version of the file(s), but you are not obligated to do so. If
 * you do not wish to do so, delete this exception statement from your
 * version. If you delete this exception statement from all source files
 * in the program, then also delete it here.
 * 
 * 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, see <http://www.gnu.org/licenses/>.
 **/


#pragma once

#include <boost/noncopyable.hpp>
#include <string>

namespace AtomIT
{
  class IFilter : public boost::noncopyable
  {
  public:
    virtual ~IFilter()
    {
    }

    virtual std::string GetName() const = 0;

    virtual void Start() = 0;

    // "Step()" must have bounded execution time to cleanly stop the
    // filter thread (ideally, no more than 500ms). The method is
    // allowed to throw exceptions. A return value of "false"
    // indicates that the filter has ended its task, and should not be
    // re-executed.
    virtual bool Step() = 0; 

    virtual void Stop() = 0;
  };
}