sl@0: // Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: // Reserving/Accessing/Releasing drive space - CSqlDriveSpace and RSqlDriveSpaceCol classes declarations
sl@0: // 
sl@0: //
sl@0: 
sl@0: #ifndef __SQLSRVDRIVESPACE_H__
sl@0: #define __SQLSRVDRIVESPACE_H__
sl@0: 
sl@0: #include <f32file.h>
sl@0: 
sl@0: //Forward declarations
sl@0: class RSqlDriveSpaceCol;
sl@0: class CSqlServer;
sl@0: 
sl@0: #ifdef _DEBUG
sl@0: #define SQLDRIVESPACE_INVARIANT() Invariant()
sl@0: #define SQLDRIVESPACECOL_INVARIANT() Invariant()
sl@0: #else
sl@0: #define SQLDRIVESPACE_INVARIANT() void(0)
sl@0: #define SQLDRIVESPACECOL_INVARIANT() void(0)
sl@0: #endif
sl@0: 
sl@0: /**
sl@0: This class describes an object, which is responsible for handling
sl@0: "reserve/get access/release" requests for a particular drive.
sl@0: 
sl@0: Since the drive may be shared between more than one server side session and there is only one RFs instance,
sl@0: the current solution is that CSqlDriveSpace objects reserve some predefined amount of disk space
sl@0: at the time of their creation and then the access to the reserved disk space is reference counted.
sl@0:     There is one obvious disadvantage of this solution: if a bad application "forgets" to release
sl@0: the access to the reserved disk space, then the reserved (but not released) disk space may be used by the server.
sl@0: At the moment, when some client will really need the reserved disk space to complete its "delete" transaction, 
sl@0: it may happen that there is no reserved disk space at all. 
sl@0: 
sl@0: @see RSqlDriveSpaceCol
sl@0: @internalComponent
sl@0: */
sl@0: NONSHARABLE_CLASS(CSqlDriveSpace) : public CBase
sl@0: 	{
sl@0: public:
sl@0: 	static CSqlDriveSpace* NewLC(RFs& aFs, TDriveNumber aDrive);
sl@0:     virtual ~CSqlDriveSpace();
sl@0: 	inline TDriveNumber Drive() const;
sl@0: 	void GetAccessL();
sl@0: 	void ReleaseAccess();
sl@0: 	void Invariant() const;
sl@0: 
sl@0: private:
sl@0: 	CSqlDriveSpace(RFs& aFs, TDriveNumber aDrive);
sl@0:     void ConstructL();
sl@0: 
sl@0: private:
sl@0: 	RFs& 			iFs;               	//File session reference
sl@0: 	TDriveNumber 	iDrive;    			//Drive number
sl@0: 	TInt 			iGetAccessRefCnt;	//"Get access" requests count
sl@0: 
sl@0: 	};
sl@0: 
sl@0: /**
sl@0: @return The drive number, where the CSqlDriveSpace object handles the reservation requests
sl@0: */
sl@0: inline TDriveNumber CSqlDriveSpace::Drive() const
sl@0:     {
sl@0:     return iDrive;
sl@0:     }
sl@0: 
sl@0: /**
sl@0: This class describes a collection of CSqlDriveSpace objects. Each CSqlDriveSpace object in the
sl@0: collection is responsible for handling "reserve/get access/release" requests for a particular
sl@0: drive.
sl@0: 
sl@0: Only one RSqlDriveSpaceCol instance should be created (resp. destroyed) by the CSqlServer object.
sl@0: 
sl@0: @see CSqlServer
sl@0: @see CSqlDriveSpace
sl@0: 
sl@0: @internalComponent
sl@0: */
sl@0: NONSHARABLE_CLASS(RSqlDriveSpaceCol)
sl@0: 	{
sl@0: public:
sl@0: 	RSqlDriveSpaceCol();
sl@0: 	void Create(RFs& aFs);
sl@0: 	void ResetAndDestroy();
sl@0:     CSqlDriveSpace* Find(TDriveNumber aDrive);
sl@0:     CSqlDriveSpace* AddL(TDriveNumber aDrive);
sl@0: 	void Invariant() const;
sl@0: 
sl@0: private:
sl@0: 	RFs*				        	iFs;            //File session reference
sl@0: 	RPointerArray<CSqlDriveSpace>	iDriveSpaceCol; //Collection of CSqlDriveSpace objects: one per drive
sl@0: 
sl@0: 	};
sl@0: 
sl@0: #endif//__SQLSRVDRIVESPACE_H__