/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#ifndef CWORKER_H_

#define CWORKER_H_

#include <e32base.h>

#define KTermDeviation 100 // The bigger this word, the more different terms

#define KPrefixDeviation 20 // Pick prefixes more moderately

#define KTermCountDeviation 10 // The bigger this word, the more terms per document

_LIT( KContentsField, "Contents" ); 

_LIT( KNormalIndexDirectory, "c:\\data\\indexing\\indexdb\\root\\test\\normal" ); 

_LIT( KBusyIndexDirectory, "c:\\data\\indexing\\indexdb\\root\\test\\busy"); 

_LIT( KTestBaseAppClass, "root test" ); 

_LIT( KNormalBaseAppClass, "root test normal"); 

_LIT( KBusyBaseAppClass, "root test busy");

_LIT( KNormalVolume, "@df:root test normal"); 

_LIT( KBusyVolume, "@df:root test busy"); 

/**

 * Returns random numbers so, that small numbers

 * are most common. Used to approximate the distribution

 * of real world worlds. In the distribution the probability that n is 

 * one of the numbers following i is 9 times as probable as that n is i. 

 */

TInt LogRand( TInt aDeviation ); 

void SleepRandom( TInt aAverageMs ); 

/**

 * Base class for workers. Workers do some kind of activity 

 * (~indexing or searching) in their own slave thread.

 */

class CWorker : public CBase 

	{

public: 

	CWorker();

	void ConstructL();

	~CWorker();

public: 

	TInt WorkerId();

public: // Error handling

	TInt Error();

	const TTime& ExitTime();

	TBool IsReported();

	void SetReported();

public: // Thread life cycle handling

	/**

	 * Returns true, if TryFinish() has been called successfully

	 */

	TBool IsActive();

	/**

	 * Starts

	 */

	void StartL(); 

	/**

	 * Signals the thread to shut down. The thread will shut down

	 * after finishing its current task.  

	 */

	void Cancel();

	/**

	 * Attempts to 'join' the thread. Returns error code, if

	 * joining failed. NOTE: unlike posix 'join', this method

	 * does not return the thread 'exit-value'. Instead use

	 * Error to see, if an error occurred during thread

	 * execution.

	 * 

	 * NOTE: Always call cancel before attempting to join 

	 * the thread.   

	 */

	TInt TryJoin( TInt aMicroSeconds );

	/**

	 * Terminates the thread forcefully

	 */

	void Terminate();

public: // Lock usage (For accessing the worker private data) 

	void Lock();

	TInt TryLock( TInt aMicroSeconds );

	void Unlock();

public:  

	virtual const TDesC& Name()= 0; 

protected: // For internal usage 

	void Wait( TReal aSeconds );

protected: 

	/**

	 * For doing any required preparations in the original thread. 

	 */

	virtual void DoPrepareL() = 0;

	virtual void DoCancel() = 0;

	virtual void DoRunL() = 0;

	void RunL();

public: 

	static TInt ThreadFunction(void *aThis);

private: 

	TInt iWorkerId; 	

	TInt iError;

	TTime iExitTime; 

	TBool iReported; 

	static TInt iNextFreeWorkerId;  

	TBool iActive; 

	RThread iThread; 

	/**

	 * This lock guards the worker thread life cycle. Before

	 * exiting, the worker thread will signal on this semaphore. 

	 * 

	 * NOTE: Logon could be used instead.  

	 */

	RSemaphore iSemaphore;

	/**

	 * This lock guards the internal state variables of this 

	 * worker. NOTE: The internal state variables are defined

	 * in the inherited classes. For example the statistics are

	 * guarded by this semaphore.  

	 */

	RSemaphore iLock; 

	};

#endif /* CWORKER_H_ */