/*

* Copyright (c) 2005-2009 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:  Manages object search from database using SQL,*

*/

#ifndef __MDSSQLFINDOPERATION_H__

#define __MDSSQLFINDOPERATION_H__

#include <e32base.h>

#include "mdccommon.h"

#include "mdssqliteconnection.h"

// FORWARD DECLARATIONS

class CMdSSqLiteConnection;

class CMdSFindSqlClause;

class CMdSFindSequence;

class CMdCSerializationBuffer;

class CDesC16Array;

class RRowData;

/**

* Find operation class represents a single synchronous

* or asynchronous find.

*/

class CMdSSqlFindOperation: public CBase

    {

    public:

	    /** state of operation */

	    enum TOperationState

	    	{

	        EStateIdle,     // not working

	        EStateRunning,  // active state

	        EStateStop,     // stop instructed

	        EStateDead,     // find stopped

	        };

        /**

        * constructs a find operation        

        * @param aFind the master class that runs this operation        

        * @param aSetSize maximum size of a single result set

        */

        static CMdSSqlFindOperation* NewL(            

            CMdSFindSequence& aFind,            

            TUint aSetSize

             );

        /**

        * constructs a find operation, leaves in cleanup stack.

        */

        static CMdSSqlFindOperation* NewLC(            

            CMdSFindSequence& aFind,            

            TUint aSetSize

             );

        virtual ~CMdSSqlFindOperation();

        /**

        * from MMdSFindOperation

        */

        TInt ExecuteL();

        /**

        * from MMdSFindOperation

        */

        TInt ContinueL();

        /**

        * from MMdSFindOperation

        */

        TInt State();

        /**

        * from MMdSFindOperation

        */

        void Cancel();

        /**

        * from MMdSFindOperation

        */

        CMdSFindSqlClause& FindCriteria();

        /**

        * Moves ownership of the result buffer to caller

        */

        CMdCSerializationBuffer* Results();

		void SetLimit(TUint32 aLimit);

		void SetOffset(TUint32 aOffset);

        /**

         * Returns query freetext array from CMdSFindSqlClause

         * @return freetext array

         */

        RPointerArray<HBufC>& QueryFreeText();

    private: // private construction for friends only

        /**

        * Construction

        */

        CMdSSqlFindOperation(            

            CMdSFindSequence& aFind,

            TUint aSetSize = KMaxTUint

             );

        /** 2nd phase constructor */

        void ConstructL();

    private: // Private functions

        /**

        * iterates results from database,

        * places them in results container

        * @return error code, KErrNone or KSetReady

        */

        TInt FetchResultsL();

		TInt EstimateBaseResultSize();

		TInt EstimateResultRowSizeL( RRowData& aRow );

        /**

        * Gets query results from the rowbuffer, creates

        * corresponding object structure and adds into the

        * results container.

        * @param aDb database connection

        * @param aRow database row to add into container

        * @return true, if data was added to container

        */

	    void AddToContainerL();

        /**

        * Special treatment for Object, which is complicated

        * because of heavy optimization

        * @param aRow database row to add into container

        * @param aFreespaceOffset offset to free space in buffer

        */

	    TMdCOffset AddObjectToContainerL( RRowData& aRow, TMdCOffset aFreespaceOffset );

        /**

        * Marks the current database rows consumed

        */

        void ConsumeRows();

        /**

        * Add data to container 

        * @param aRow database row to add into container

        * @param aFreespaceOffset offset to free space in buffer

        */

        TMdCOffset AddItemToContainerL( RRowData &aRow, TMdCOffset aFreespaceOffset );

        /**

        * Add data to container 

        * @param aId item ID to add into container

        */

        void AddIdToContainerL( TItemId aId );

        /**

        * Creates Item for serialization

        */

        void CreateItemL();

        /**

        * Creates count for serialization

        */

        void CreateCountL();

        /**

        * Creates Id for serialization

        */

        void CreateIdL();

        /**

        * Creates distinct properties for serialization

        */

        void CreateDistinctL();

    private: // Member data

        /** Find type */

        TQueryType iQueryType;

		/** Result mode */

		TQueryResultMode iResultMode;

        /**

        * Data row in find.

        * Note: RRowData constructor cannot leave, since it is initialized (aInStack==EFalse)

        */

		RRowData* iResultRow;

        /**

        * Fetched result rows. Used when result mode is items or distinct.

        * Note: RRowData constructor cannot leave, since it is initialized (aInStack==EFalse)

        */

        RPointerArray<RRowData> iResultRows;

        /**

        * Fetched result IDs. Used when result mode is IDs.

        */

        RArray<TItemId> iResultIds;

        /**

        * Fetched result count. Used when result mode is count.

        */

        TUint32 iResultCount;

        /** container for result objects */

        CMdCSerializationBuffer* iResults;

        /** the object find back reference */

        CMdSFindSequence& iFind;

        /** the find SQL clause */

        CMdSFindSqlClause* iFindClause;

        /** asynchronous run state */

        TOperationState iState;

        /** the query ID */

        RMdsStatement iQueryId;

        /** maximum size of a single set */

        const TUint32 iSetSize;

        /** counter for results in this set */

        TUint iSetCounter;

        /** maximum size of the whole search */

        TUint iLimit;

        /** maximum size of the whole search */

        TUint iLimitCounter;

        /** offset from beginning of the sequence */

        TUint iOffset;

        /** used memory from set buffer */

        TInt iMemoryLimit;

        /** harvesting prioritization URI count */

        TInt iHarvestingPrioritizationCount;

    };

#endif // __MDSSQLFINDOPERATION_H__