--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/authenticationservices/authenticationserver/source/server/evaluator.h	Tue Nov 24 09:06:03 2009 +0200
@@ -0,0 +1,211 @@
+/*
+* 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 the License "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: 
+* Evaluator mix-in classes implementation
+*
+*/
+
+
+/**
+ @file 
+ @released
+ @internalComponent 
+*/
+ 
+#ifndef AUTHSERVER_EVALUATOR_H
+#define AUTHSERVER_EVALUATOR_H
+
+#include "authexpression_impl.h"
+
+namespace AuthServer {
+
+class MEvaluatorPluginInterface
+/**
+	CEvaluator uses this interface to invoke a plugin,
+	which can be specified by type or ID.
+	
+	@see CEvaluator
+ */
+	{
+public:
+	/**
+		Invoke the specified plugin and record the identity
+		which was returned.
+		
+		@param	aPluginId		Plugin to use.
+		@param	aIdentityId		On successful completion this
+								object is set to the returned
+								identity.
+		@param	aType			The type of plugin represented 
+								by this instance.						
+		@param	aStatus			On completion (successful or
+								otherwise) this object is
+								completed with the error code.
+	 */
+	virtual void Evaluate(TPluginId aPluginId, TIdentityId& aIdentityId, 
+						  CAuthExpressionImpl::TType aType, TRequestStatus& aStatus) = 0;
+
+	/**
+	    Cancel the plugin currently being invoked.
+	 **/
+	virtual void CancelEvaluate() = 0;
+	
+	/**
+		Invoke a plugin of the requested type and record
+		the identity which was returned.
+		
+		@param	aPluginType		Type of plugin to use.  The
+								implementation maps this to a
+								single, specific plugin.
+		@param	aIdentityId		On successful completion this
+								object is set to the returned
+								identity.
+		@param	aType			The type of plugin represented 
+								by this instance.						
+		@param	aStatus			On completion (successful or
+								otherwise) this object is
+								completed with the error code.
+	 */
+	virtual void Evaluate(TAuthPluginType aPluginType, TIdentityId& aIdentityId, 
+						  CAuthExpressionImpl::TType aType, TRequestStatus& aStatus) = 0;
+	};
+
+class MEvaluatorClientInterface
+/**
+	CEvaluator uses this interface to notify the server
+	when an evaluation has finished, successfully or otherwise.
+	
+	The server implements this interface to notify
+	the client that the authentication request has
+	completed.
+ */
+	{
+public:
+	/**
+		This function is called by the evaluator when it
+		has successfully parsed and evaluated an expression.
+		
+		In this context, successful means there were no
+		errors in running the plugins, or otherwise in
+		evaluating the expression, such as OOM.  It does
+		not mean that a specific user was identified -
+		aIdentity can still be CIdentity::KUnknown.
+		
+		@param	aIdentityId		Identified user.  This can
+								be CIdentity::KUnknown.
+		@see EvaluationFailed
+	 */
+	virtual void EvaluationSucceeded(TIdentityId aIdentityId) = 0;
+	/**
+		This function is called by the evaluator when
+		it has failed to evaluate an expression.  Reasons
+		for failure include failing to run a plugin;
+		the user cancelling a plugin; OOM; and others.
+		
+		Failure in this sense does not means the expression
+		was evaluated but no specific user was identified.
+		That case is handled by EvaluationSucceeded.
+		
+		@param	aReason		Symbian OS error code.
+		
+		@see EvaluationSucceeded
+	 */
+	virtual void EvaluationFailed(TInt aReason) = 0;
+	};
+
+class CEvaluator : public CActive
+/**
+	Expression evaluator.  This asynchronously
+	evaluates the supplied expression by calling
+	the referenced plugins.
+ */
+	{
+public:
+	static CEvaluator* NewL(MEvaluatorPluginInterface* aPluginInterface, MEvaluatorClientInterface* aClientInterface);
+	virtual ~CEvaluator();
+
+	void Evaluate(const CAuthExpressionImpl* aExpr);
+	
+private:
+	CEvaluator(MEvaluatorPluginInterface* aPluginInterface, MEvaluatorClientInterface* aClientInterface);
+	void ConstructL();
+	
+	void EvaluatedNode(TIdentityId aIdentity);
+	void EvaluateCompound(const CAuthExpressionImpl* aParent);
+	void ReplaceComplexIdentity(TIdentityId aIdentity);
+	
+	// complete client request
+	void NotifyClientSucceeded(TIdentityId aIdentity);
+	void NotifyClientFailed(TInt aReason);
+	
+	// manipulate RPN stack
+	TBool PushIdentity(TIdentityId aIdentity);
+	TIdentityId PopIdentity();
+	TIdentityId& LastIdentity();
+	void ResetRpnStack();
+	// implement CActive
+	virtual void RunL();
+	virtual void DoCancel();
+	
+#ifdef _DEBUG
+	enum TPanic
+		{
+		EENRpnStackNonZero = 0x10,
+		EECRpnStackTooLow = 0x20, EECBadParentType, EECRpnStackNotOneAtRoot, EECBadRightParent,
+		EBusy = 0x30,
+		};
+	static void Panic(TPanic aPanic);
+	TInt RpnDepth() const;
+#endif
+	
+private:
+	/** The evaluator uses this to invoke plugins. */
+	MEvaluatorPluginInterface*const iPluginInterface;
+	/**
+		The evaluator uses this to notify the server
+		when an evaluation has completed, successfully
+		or otherwise.
+	 */
+	MEvaluatorClientInterface*const iClientInterface;
+	
+	/** Constant value defined for short name readability only. */
+	static const CAuthExpressionImpl::TType KAnd;
+	/** Constant value defined for short name readability only. */
+	static const CAuthExpressionImpl::TType KOr;
+
+	/** The expression which is currently being evaluated. */
+	const CAuthExpressionImpl* iCurrentNode;
+	
+	/** The plugin sets this value to the returned identity. */
+	TIdentityId iIdentity;
+	
+	/**
+		Granularity of RPN stack.  This value should be large
+		to parse a reasonable expression without having to
+		reallocate, and without wasting too much memory.
+	 */
+	static const TInt KRPNGranularity;
+	/**
+		Intermediate results.  (A CArrayFixFlat is used here
+		instead of an RArray because, although it uses more
+		memory, it can be resized when items are popped.)
+	 */
+	CArrayFixFlat<TIdentityId>* iRpnStack;
+	};
+
+}	// namespace AuthServer
+
+#endif	// #ifndef AUTHSERVER_EVALUATOR_H
+
+