/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkLoggerThreadWrapper.h,v $
  Language:  C++
  Date:      $Date: 2009-02-05 19:05:01 $
  Version:   $Revision: 1.9 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/

#ifndef __itkLoggerThreadWrapper_h
#define __itkLoggerThreadWrapper_h

//NOTE: This class does not work under MSVS6, or gnu 2.95
#if ! ( defined(_MSC_VER) || ( defined(__GNUC__) && (__GNUC__ <= 2) ))

#include "itkMacro.h"
#include "itkMultiThreader.h"
#include "itkSimpleFastMutexLock.h"

#include <string>
#include <queue>

namespace itk
{

/** \class LoggerThreadWrapper
 *  \brief Class LoggerThreadWrapper is meant for providing logging service 
 *  as a separate thread.
 *
 * \author Hee-Su Kim, Compute Science Dept. Kyungpook National University,
 *                     ISIS Center, Georgetown University.
 *
 *  \ingroup OSSystemObjects LoggingObjects
 */

// MSVS6 can't do this type of nested template
template < class SimpleLoggerType >
class LoggerThreadWrapper : public SimpleLoggerType
{
public:
  
  typedef LoggerThreadWrapper       Self;
  typedef SimpleLoggerType          Superclass;
  typedef SmartPointer<Self>        Pointer;
  typedef SmartPointer<const Self>  ConstPointer;
  
  /** Run-time type information (and related methods). */
  itkTypeMacro( LoggerThreadWrapper, SimpleLoggerType );
  
  /** New macro for creation of through a Smart Pointer */
  itkNewMacro( Self );
  
  typedef  typename SimpleLoggerType::OutputType         OutputType;
  typedef  typename SimpleLoggerType::PriorityLevelType  PriorityLevelType;
  
  /** Definition of types of operations for LoggerThreadWrapper. */
  typedef enum
    {
    SET_PRIORITY_LEVEL,
    SET_LEVEL_FOR_FLUSHING,
    ADD_LOG_OUTPUT,
    WRITE,
    FLUSH
    } OperationType;
  
  
  /** Set the priority level for the current logger. Only messages that have
   * priorities equal or greater than the one set here will be posted to the
   * current outputs */
  virtual void SetPriorityLevel( PriorityLevelType level );
  
  /** Get the priority level for the current logger. Only messages that have
   * priorities equal or greater than the one set here will be posted to the
   * current outputs */
  virtual PriorityLevelType GetPriorityLevel() const;
  
  virtual void SetLevelForFlushing( PriorityLevelType level );
  virtual PriorityLevelType GetLevelForFlushing() const;
  
  /** Registers another output stream with the multiple output. */
  virtual void AddLogOutput( OutputType* output );
  
  virtual void Write(PriorityLevelType level, std::string const & content);
  
  virtual void Flush();
  
protected:
  
  /** Constructor */
  LoggerThreadWrapper();
  
  /** Destructor */
  virtual ~LoggerThreadWrapper();
  
  /** Print contents of a LoggerThreadWrapper */
  virtual void PrintSelf(std::ostream &os, Indent indent) const;
  
  static ITK_THREAD_RETURN_TYPE ThreadFunction(void*);
  
private:
  
  typedef std::queue<OperationType> OperationContainerType;
  
  typedef std::queue<std::string>  MessageContainerType;
  
  typedef std::queue<PriorityLevelType>  LevelContainerType;
  
  typedef std::queue<typename OutputType::Pointer>  OutputContainerType;
  
  MultiThreader::Pointer  m_Threader;
  
  int m_ThreadID;
  
  OperationContainerType  m_OperationQ;
  
  MessageContainerType  m_MessageQ;
  
  LevelContainerType  m_LevelQ;
  
  OutputContainerType m_OutputQ;
  
  SimpleFastMutexLock m_Mutex;
  
  SimpleFastMutexLock m_WaitMutex;
  
};  // class LoggerThreadWrapper
} // namespace itk
  
#ifndef ITK_MANUAL_INSTANTIATION
#include "itkLoggerThreadWrapper.txx"
#endif
  
  
  
#endif  // !defined (_MSC_VER)
#endif  // __itkLoggerThreadWrapper_h
