/*
 * LinkedCell_Model_LinkedCellArrayCache.hpp
 *
 *  Created on: Dec 20, 2011
 *      Author: heber
 */

#ifndef LINKEDCELL_MODEL_LINKEDCELLARRAYCACHE_HPP_
#define LINKEDCELL_MODEL_LINKEDCELLARRAYCACHE_HPP_

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <boost/function.hpp>

#include "CodePatterns/Cacheable.hpp"

#include "LinkedCell_Model.hpp"

#include "types.hpp"

namespace LinkedCell {

  /** This class is used to separate reading from writing access.
   *
   * Write operations are stored and perform first (lazily) when the next read
   * operation requires a fully update instance.
   *
   */
  class LinkedCell_Model::LinkedCellArrayCache {
    //!> grant LinkedCell_Model access to N for its write operations.
    friend class LinkedCell_Model;
    //!> grant access to model's unit test (to externally allow for update before checking internals)
    friend class ::LinkedCell_ModelTest;
  public:
    LinkedCellArrayCache(
        Observable *_observable,
        boost::function<void ()> _updatefunction,
        const std::string _name);
    ~LinkedCellArrayCache();

    const LinkedCellArray &getN() const;

    /** Internal update function for Cacheable UpToDate.
     *
     * @return true after updatefunction was called.
     */
    bool updateMe() {
      updatefunction();
      return true;
    }

  private:
    LinkedCellArray &setN();

    //!> update function
    boost::function<void ()> updatefunction;

    /** Pseudo variable to use the Cacheable pattern.
     *
     * We cannot use a complex variable for this due the cost of the cstor
     * involved as the update always returns the updated structure
     */
    Cacheable<bool> UpToDate;

    //!> Linked cell array cache
    LinkedCellArray N;

  };

} // namespace LinkedCell


#endif /* LINKEDCELL_MODEL_LINKEDCELLARRAYCACHE_HPP_ */