--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/loggingservices/eventlogger/LogServ/inc/LogServCacheStrings.h	Fri Jan 22 11:06:30 2010 +0200
@@ -0,0 +1,118 @@
+// Copyright (c) 2002-2009 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 __LOGSERVCACHESTRINGS_H__
+#define __LOGSERVCACHESTRINGS_H__
+
+#include <logwrap.h>
+#include <logwraplimits.h>
+
+// Classes referenced
+class MLogServDatabaseTransactionInterface;
+
+/**
+Caches the most often used strings, such as "Incoming", "Outgoing", "Missed", etc.
+Every string in the cache is identified by an ID. The cached strings come from 
+event's "status" and "direction" fields. If an event is about to be added to the events database
+table, instead of storing in the table often repeated "status" and "direction" string fields values,
+the CLogServCacheStrings is searched for the ID of the string. If such string is already in the cache
+its ID is returned, if no such string is found in the cache, then the string will be added to the cache 
+and the ID of the added string is returned. The returned ID will be stored as part of the event 
+properties in the events table. 
+
+Wherever the strings cache is changed, if the database is already in transaction, the cache changes will
+be committed/rolled back when the transaction is committed/rolled back.
+
+Note: the often used LogEng strings are kept in a database table with name "String".
+
+@see CLogAddEvent
+@see CLogEvent
+@see MLogServDatabaseTransactionInterface
+@internalComponent
+*/
+class CLogServCacheStrings : public CBase
+	{
+public:
+	static CLogServCacheStrings* NewL(MLogServDatabaseTransactionInterface& aDatabase);
+	~CLogServCacheStrings();
+
+	const TPtrC  FindString(TLogStringId aId) const;
+	TLogStringId FindId(const TDesC& aString);
+	TLogStringId GetIdL(const TDesC& aString);
+	void Commit();
+	void Rollback();
+
+private:
+   	struct TLogServCacheStringEntry
+		{
+		public:
+			static void CleanupEntry(TAny* aEntry);
+			static inline TLogServCacheStringEntry* NewEntryL(TLogStringId aId, const TDesC& aString, TBool aDirty = EFalse)
+				{
+				TUint8* entry = (TUint8*)User::AllocL(sizeof(TLogServCacheStringEntry) + aString.Size());
+				return new (entry) TLogServCacheStringEntry(aId, aString, aDirty);
+				}
+			static inline TLogServCacheStringEntry* NewEntryLC(TLogStringId aId, const TDesC& aString, TBool aDirty = EFalse)
+				{
+				TLogServCacheStringEntry* entry = TLogServCacheStringEntry::NewEntryL(aId, aString, aDirty);
+				CleanupStack::PushL(TCleanupItem(&TLogServCacheStringEntry::CleanupEntry, entry));
+				return entry;
+				}
+			static inline void DeleteEntry(TLogServCacheStringEntry* aEntry)
+				{
+				User::Free(aEntry);
+				}
+			inline const TPtrC String() const
+				{
+				return TPtrC(iString, iStringLength);
+				}
+		private:
+			inline TLogServCacheStringEntry(TLogStringId aId, const TDesC& aString, TBool aDirty) :
+				iId(aId),
+				iDirty(aDirty),
+				iStringLength(aString.Length())
+				{
+				(void)Mem::Copy(iString, aString.Ptr(), aString.Size());
+				}
+			TLogServCacheStringEntry();				
+			TLogServCacheStringEntry(const TLogServCacheStringEntry&);
+			TLogServCacheStringEntry& operator=(const TLogServCacheStringEntry&);
+		public:		
+			TLogStringId 	iId;
+			TBool 			iDirty;//if set, this entry has been added to the cache during transaction
+		private:			
+			TInt 			iStringLength;
+			TText 			iString[1];
+		};
+
+	CLogServCacheStrings(MLogServDatabaseTransactionInterface& aDatabase);
+	void ConstructL();
+	void ReadStringsFromDatabaseL();
+	TLogStringId DoAddStringL(const TDesC& aString);
+	void DestroyCache();
+	void InitializeColNumsL(RDbRowSet& aRowSet);
+	static TInt Compare1(const TDesC* aString, TLogServCacheStringEntry* const& aRight);
+	static TInt Compare2(TLogServCacheStringEntry* const& aLeft, TLogServCacheStringEntry* const& aRight);
+
+private:
+	MLogServDatabaseTransactionInterface& iDatabase;
+	RArray<TLogServCacheStringEntry*> iStrings;//List of cached strings
+	TBool iDirty;//iDirty flag is set when strings are added to the cache during transaction
+	TDbColNo iIdColNo;
+	TDbColNo iStringColNo;
+	
+	};
+
+#endif