--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/persistentstorage/sql/SRC/Client/IPC/IPCBuf.h	Fri Jan 22 11:06:30 2010 +0200
@@ -0,0 +1,106 @@
+// 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:
+//
+
+#ifndef __IPCBUF_H__
+#define __IPCBUF_H__
+
+#include <s32buf.h>
+#include "IpcDefs.h"
+
+//Forward declarations
+class TIpcArgs;
+class RSqlDbSession;
+
+/**
+HIpcBuf class manages the "client to server" transfer of large data blocks.
+
+It caches the data to be sent/retrieved on the client side and sychronises the content of the client-side cache
+with the content of a similar server-side cache, sending appropriate read/write/sync commands to the server.
+
+An instance of TIpcStreamBuf class is uased as a client-side cache.
+
+The following code fragment shows how the class can be used to send to the server large blocks of data:
+
+@code
+//Step 1: Create the HIpcBuf instance.
+HIpcBuf* ipcBuf = HIpcBuf::NewLC(params, function, args);
+
+//Step 2: Create a stream instance. It will be used for sending the data to the server. All details about
+//		  the data transfer will be performed by the ipcBuf object.
+RWriteStream out(ipcBuf);
+
+//Step 3: "TheObject" is some large data object which has to be sent to the server. Let's assume 
+//		  "TheObject" has ExternalizeL() function which can be used to externalize the object into an output stream.
+TheObject.ExternalizeL(out);
+
+//Step 4: Commit the output stream. After the commit command the server will have all the data transferred.
+out.CommitL();		
+
+//Step 5: Cleanup.
+CleanupStack::PopAndDestroy(ipcBuf);
+@endcode
+
+@see RSqlDbSession;
+@see TIpcStreamBuf
+@see RSessionBase
+
+@internalComponent
+*/
+NONSHARABLE_CLASS(HIpcBuf) : public TStreamBuf
+	{
+public:
+	static HIpcBuf* NewL(RSqlDbSession& aSession, TInt aFunction, TIpcArgs& aArgs);
+	static HIpcBuf* NewLC(RSqlDbSession& aSession, TInt aFunction, TIpcArgs& aArgs);
+	virtual ~HIpcBuf();
+	
+private:
+	HIpcBuf(RSqlDbSession& aSession);
+	void ConstructL(TInt aFunction, TIpcArgs& aArgs);
+	
+	// from TStreamBuf
+	TInt UnderflowL(TInt aMaxLength);
+	void OverflowL();
+	void DoRelease();
+	void DoSynchL();
+	TInt DoReadL(TAny* aPtr, TInt aMaxLength);
+	void DoWriteL(const TAny* aPtr, TInt aLength);
+	TStreamPos DoSeekL(TMark aMark, TStreamLocation aLocation, TInt anOffset);
+	
+private:
+	inline void SetPos(TRead, TInt aPos);
+	inline void SetPos(TWrite, TInt aPos);
+	inline TInt Pos(TRead) const;
+	inline TInt Pos(TWrite) const;
+	inline TInt MovePos(TRead, TInt aOffset);
+	TInt IpcReadL(TAny* aPtr, TInt aMaxLength);
+	void IpcWriteL(const TAny* aPtr, TInt aLength);
+	TInt EndL();
+
+	inline TInt Lag(TRead) const;
+	inline TInt Lag(TWrite) const;
+	inline TInt Mark(TRead) const;
+	inline TInt Mark(TWrite) const;
+	
+private:
+	RSqlDbSession& 	iSession;
+	TInt			iHandle;
+	TInt 			iRPos;
+	TInt 			iWPos;
+	TIpcStreamBuf	iBuf;
+	};
+
+#include "IPCBuf.inl"
+
+#endif//__IPCBUF_H__