--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pimappsupport/vcardandvcal/inc/VersitTls.h	Tue Feb 02 10:12:19 2010 +0200
@@ -0,0 +1,110 @@
+// Copyright (c) 1997-2009 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 __VERSITTLS_H__
+#define __VERSITTLS_H__
+
+// System includes
+#include <e32base.h>
+#include <charconv.h>
+
+#include <vutil.h>
+
+class CVersitTimer;
+class CVersitAdditionalStorage;
+
+class CVersitTlsData : public CBase
+/** Versit thread local storage.
+
+This class provides a performance improvement by allowing a CVersitUnicodeUtils 
+instance to be shared between parsers operating in the same thread, so that 
+a new instance does not have to be created for each parser. A pointer to the 
+unicode utilities object is held in thread local storage: a single word (32bits) 
+of data. Each unicode utilities object is managed by an instance of this class.
+
+Every time a parser is created, CVersitParser::ConstructL() calls the 
+CVersitTlsData constructor, and when the parser is destroyed the CVersitTlsData 
+destructor is called. If a CVersitTlsData object exists, the constructor 
+returns a pointer to it, otherwise a new one is constructed. The CVersitTlsData 
+object is only destroyed when no more parsers refer to it: a count is kept, 
+which is incremented every time the constructor is called and decremented each 
+time the destructor is called, and the object is only destroyed when the count 
+reaches zero.
+
+This class provides an additional major performance improvement 
+if you are sequentially constructing and destructing multiple parsers. 
+By default, when the count of parsers reaches zero, the thread local 
+storage object is destroyed (even if the thread has not finished). However, 
+by using the technique described below, the thread local storage object, and therefore 
+the unicode utilities object, can be made to persist, significantly reducing 
+the overhead of sequentially constructing and destructing parsers.
+
+The constructor needs to be called an extra time before creating any parsers, 
+and the destructor needs to be called an extra time once the parsers have 
+been destroyed. This has the effect of adding one to the reference count so 
+that during all the parser construction and deletion the count never hits 
+zero, which would trigger the TLS object's destruction.
+
+This can be implemented as follows:
+
+1. Create a thread local storage data class instance as follows: 
+@code
+CVersitTlsData* versitTLS = CVersitTlsData::VersitTlsDataL(); 
+@endcode
+
+2. Create and delete the parsers. 
+
+3. Delete the Thread Local Storage Data class instance: 
+@code
+delete versitTLS; 
+@endcode 
+@publishedAll
+@released
+*/
+	{
+	friend class CVersitTimer;
+
+public:
+	IMPORT_C static CVersitTlsData& VersitTlsDataL();
+	IMPORT_C static void CloseVersitTlsData();
+	IMPORT_C void VersitTlsDataClose();
+
+public:
+	inline CVersitUnicodeUtils& UnicodeUtils() 
+	/** Returns a pointer to the current Unicode utilities object.
+	
+	@return A pointer to the current Unicode utilities object. */
+		{ return *iUnicodeUtils; }
+
+    inline CVersitAdditionalStorage& AdditionalStorage()
+	/** Returns a pointer to the additional property storage object.
+	
+	@return A pointer to the additional property storage. */
+        {
+        return *iAdditionalStorage;
+        }
+
+private:
+	static CVersitTlsData* NewL();
+	void ConstructL();
+	~CVersitTlsData();
+
+private:
+	TInt iRefCount;
+	CVersitUnicodeUtils* iUnicodeUtils;
+    CVersitAdditionalStorage* iAdditionalStorage;
+	};
+
+#endif