backupandrestore/backupengine/src/sbheapwrapper.cpp
changeset 0 d0791faffa3f
child 15 f85613f12947
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/backupandrestore/backupengine/src/sbheapwrapper.cpp	Tue Feb 02 01:11:40 2010 +0200
@@ -0,0 +1,147 @@
+// Copyright (c) 2004-2009 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:
+// CHeapWrapper implementation
+// 
+//
+
+/**
+ @file
+ @internalTechnology
+*/
+
+#include "sbheapwrapper.h"
+#include <connect/panic.h>
+
+namespace conn
+	{
+	CHeapWrapper* CHeapWrapper::NewL()
+	/**
+	Symbian 1st phase constructor
+	
+	@return pointer to a newly created CHeapWrapper object
+	*/
+		{
+		CHeapWrapper* self = new (ELeave) CHeapWrapper();
+		
+		return self;
+		}
+	
+	TPtrC8& CHeapWrapper::ReadBufferL(const RChunk& aChunk)
+	/**
+	Getter for the GSH descriptor
+	
+	@param aChunk The RChunk to interrogate for the heap information
+	@return reference to the descriptor stored on the global shared heap
+	*/
+		{
+		if (Header(aChunk).LockedFlag())
+			{
+			User::Leave(KErrInUse);
+			}
+
+		CleanReadBuffer();
+			
+		iReadBuf = new (ELeave) TPtrC8(Buffer(aChunk));
+
+		return *iReadBuf;
+		}
+		
+	TPtr8& CHeapWrapper::WriteBufferL(const RChunk& aChunk)
+	/**
+	Lock the heap and return a reference to the descriptor on the GSH
+	
+	@param aChunk The RChunk to interrogate for the heap information
+	@return reference to the descriptor stored on the global shared heap
+	*/
+		{
+		if (Header(aChunk).LockedFlag())
+			{
+			User::Leave(KErrInUse);
+			}
+
+		CleanReadBuffer();
+
+		TPtr8& des = Buffer(aChunk);
+		
+		// Blank the descriptor as it's a write buffer
+		des.Zero();
+		
+		return des;
+		}
+		
+	THeapWrapperHeader& CHeapWrapper::Header(const RChunk& aChunk) const
+	/**
+	Getter for the protocol structure
+	
+	@param aChunk The RChunk to interrogate for the heap information
+	@return Pointer to the header structure containing heap protocol information
+	*/
+		{
+		return *reinterpret_cast<THeapWrapperHeader*>(aChunk.Base() + KHeaderOffset);
+		}
+		
+	TInt CHeapWrapper::ResetHeap(const RChunk& aChunk)
+	/**
+	Reset all of the protocol data in the stack if we're the first users
+	
+	@param aChunk The RChunk to interrogate for the heap information
+	@return KErrNone always.
+	*/
+		{
+		TInt err = KErrNone;
+		TUint8* heapPtr = aChunk.Base();
+		
+		new (&Header(aChunk)) THeapWrapperHeader;
+		
+		THeapWrapperHeader& header = Header(aChunk);
+		header.iFinished = ETrue;
+		header.SetLockedFlag(EFalse);
+		
+		// placement new a new descriptor on the heap to initialise it
+		new (heapPtr + KDescriptorOffset) TPtr8(heapPtr + KDataOffset, 0, aChunk.Size() - KDataOffset);
+
+		return err;
+		}
+
+	TPtr8& CHeapWrapper::Buffer(const RChunk& aChunk)
+ 	/**
+ 	@param aChunk The RChunk to interrogate for the heap information
+ 	@return reference to the descriptor stored on the global shared heap
+ 	*/
+  		{
+  		TUint8* heapPtr = aChunk.Base();
+		
+		// Set the descriptor
+		TPtr8* descriptor = reinterpret_cast<TPtr8*>(heapPtr + KDescriptorOffset);
+		const TInt length = descriptor->Length();
+		const TInt maxLength = descriptor->MaxLength();
+		descriptor->Set(heapPtr + KDataOffset, length, maxLength);
+
+		return *descriptor;
+		}
+		
+	void CHeapWrapper::CleanReadBuffer()
+	/**
+	Delete and NULL the read buffer if necessary
+	*/
+		{
+		delete iReadBuf;
+		iReadBuf = NULL;
+		}
+		
+	CHeapWrapper::~CHeapWrapper()
+		{
+		CleanReadBuffer();
+		}
+	}