1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/persistentdata/persistentstorage/sql/SRC/Client/IPC/IPCBuf.h	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,106 @@
     1.4 +// Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.5 +// All rights reserved.
     1.6 +// This component and the accompanying materials are made available
     1.7 +// under the terms of "Eclipse Public License v1.0"
     1.8 +// which accompanies this distribution, and is available
     1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
    1.10 +//
    1.11 +// Initial Contributors:
    1.12 +// Nokia Corporation - initial contribution.
    1.13 +//
    1.14 +// Contributors:
    1.15 +//
    1.16 +// Description:
    1.17 +//
    1.18 +
    1.19 +#ifndef __IPCBUF_H__
    1.20 +#define __IPCBUF_H__
    1.21 +
    1.22 +#include <s32buf.h>
    1.23 +#include "IpcDefs.h"
    1.24 +
    1.25 +//Forward declarations
    1.26 +class TIpcArgs;
    1.27 +class RSqlDbSession;
    1.28 +
    1.29 +/**
    1.30 +HIpcBuf class manages the "client to server" transfer of large data blocks.
    1.31 +
    1.32 +It caches the data to be sent/retrieved on the client side and sychronises the content of the client-side cache
    1.33 +with the content of a similar server-side cache, sending appropriate read/write/sync commands to the server.
    1.34 +
    1.35 +An instance of TIpcStreamBuf class is uased as a client-side cache.
    1.36 +
    1.37 +The following code fragment shows how the class can be used to send to the server large blocks of data:
    1.38 +
    1.39 +@code
    1.40 +//Step 1: Create the HIpcBuf instance.
    1.41 +HIpcBuf* ipcBuf = HIpcBuf::NewLC(params, function, args);
    1.42 +
    1.43 +//Step 2: Create a stream instance. It will be used for sending the data to the server. All details about
    1.44 +//		  the data transfer will be performed by the ipcBuf object.
    1.45 +RWriteStream out(ipcBuf);
    1.46 +
    1.47 +//Step 3: "TheObject" is some large data object which has to be sent to the server. Let's assume 
    1.48 +//		  "TheObject" has ExternalizeL() function which can be used to externalize the object into an output stream.
    1.49 +TheObject.ExternalizeL(out);
    1.50 +
    1.51 +//Step 4: Commit the output stream. After the commit command the server will have all the data transferred.
    1.52 +out.CommitL();		
    1.53 +
    1.54 +//Step 5: Cleanup.
    1.55 +CleanupStack::PopAndDestroy(ipcBuf);
    1.56 +@endcode
    1.57 +
    1.58 +@see RSqlDbSession;
    1.59 +@see TIpcStreamBuf
    1.60 +@see RSessionBase
    1.61 +
    1.62 +@internalComponent
    1.63 +*/
    1.64 +NONSHARABLE_CLASS(HIpcBuf) : public TStreamBuf
    1.65 +	{
    1.66 +public:
    1.67 +	static HIpcBuf* NewL(RSqlDbSession& aSession, TInt aFunction, TIpcArgs& aArgs);
    1.68 +	static HIpcBuf* NewLC(RSqlDbSession& aSession, TInt aFunction, TIpcArgs& aArgs);
    1.69 +	virtual ~HIpcBuf();
    1.70 +	
    1.71 +private:
    1.72 +	HIpcBuf(RSqlDbSession& aSession);
    1.73 +	void ConstructL(TInt aFunction, TIpcArgs& aArgs);
    1.74 +	
    1.75 +	// from TStreamBuf
    1.76 +	TInt UnderflowL(TInt aMaxLength);
    1.77 +	void OverflowL();
    1.78 +	void DoRelease();
    1.79 +	void DoSynchL();
    1.80 +	TInt DoReadL(TAny* aPtr, TInt aMaxLength);
    1.81 +	void DoWriteL(const TAny* aPtr, TInt aLength);
    1.82 +	TStreamPos DoSeekL(TMark aMark, TStreamLocation aLocation, TInt anOffset);
    1.83 +	
    1.84 +private:
    1.85 +	inline void SetPos(TRead, TInt aPos);
    1.86 +	inline void SetPos(TWrite, TInt aPos);
    1.87 +	inline TInt Pos(TRead) const;
    1.88 +	inline TInt Pos(TWrite) const;
    1.89 +	inline TInt MovePos(TRead, TInt aOffset);
    1.90 +	TInt IpcReadL(TAny* aPtr, TInt aMaxLength);
    1.91 +	void IpcWriteL(const TAny* aPtr, TInt aLength);
    1.92 +	TInt EndL();
    1.93 +
    1.94 +	inline TInt Lag(TRead) const;
    1.95 +	inline TInt Lag(TWrite) const;
    1.96 +	inline TInt Mark(TRead) const;
    1.97 +	inline TInt Mark(TWrite) const;
    1.98 +	
    1.99 +private:
   1.100 +	RSqlDbSession& 	iSession;
   1.101 +	TInt			iHandle;
   1.102 +	TInt 			iRPos;
   1.103 +	TInt 			iWPos;
   1.104 +	TIpcStreamBuf	iBuf;
   1.105 +	};
   1.106 +
   1.107 +#include "IPCBuf.inl"
   1.108 +
   1.109 +#endif//__IPCBUF_H__