contextframework/cfw/inc/cfserver/CFContextManager.h
changeset 0 2e3d3ce01487
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contextframework/cfw/inc/cfserver/CFContextManager.h	Tue Feb 02 10:12:00 2010 +0200
@@ -0,0 +1,364 @@
+/*
+* Copyright (c) 2006-2006 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:  CFContextManager.
+*
+*/
+
+
+
+#ifndef C_CFCONTEXTMANAGER_H
+#define C_CFCONTEXTMANAGER_H
+
+// INCLUDES
+#include "cfcontextobject.h"
+#include "CFSecurityChecker.h"
+
+#include <e32base.h>
+#include <f32file.h>
+
+#include "CFContextQueryImpl.h"
+#include "CFContextObjectImpl.h"
+
+
+// FORWARD DECLARATIONS
+//class TCFSubscription;
+class CCFCacheElement;
+class CCFContextSubscription;
+class CCFContextSubscriptionImpl;
+class MCFContextSubscriptionListener;
+class MCFContextSource;
+class CCFContextDataObject;
+
+typedef TBool ( CCFContextQueryImpl::*queryMatchFunction )
+( const TDesC&, const TDesC& ) const;
+
+
+/**
+* Front-end class for data storage access.
+*  Data storage service provider for CF Server. This manager stores contexts
+*  into a cache.
+*
+*  The cache stores the latest context for each type for fast change
+*  comparison (and quick query latest response).
+*/
+NONSHARABLE_CLASS( CCFContextManager ): public CBase
+    {
+    public: // constructors and destructor
+    
+        static CCFContextManager* NewL( MCFSecurityChecker& aSecurityChecker );
+        static CCFContextManager* NewLC( MCFSecurityChecker& aSecurityChecker );
+    
+        ~CCFContextManager();
+        
+    public: // new functions
+
+	    /**
+	     * Defines a new context in Context Framework.
+	     * Every context needs to be defined before it can be published
+	     * and subscribed.
+	     * If the context is already defined KErrPermissionDenied is
+	     * returned.
+	     *
+	     * @since S60 5.0
+	     * @param aContextSource Source of the context.
+	     * @param aContextType Type of the context.
+	     * @param aReadSecurityPolicy Needed read capabilities for the context.
+	     * @param aWriteSecurityPolicy Needed write capabilities for the context
+	     * @return None
+	     */
+	    void DefineContextL( const TDesC& aContextSource,
+	    	    const TDesC& aContextType,
+	    	    const TSecurityPolicy& aReadSecurityPolicy,
+	    	    const TSecurityPolicy& aWriteSecurityPolicy);
+    
+	    /**
+	     * Defines a new context in Context Framework.
+	     * Every context needs to be defined before it can be published
+	     * and subscribed.
+	     * If the context is already defined KErrPermissionDenied is
+	     * returned.
+	     *
+	     * @since S60 5.0
+	     * @param aContextSource Source of the context.
+	     * @param aContextType Type of the context.
+	     * @param aReadSecurityPolicy Needed read capabilities for the context.
+	     * @param aWriteSecurityPolicy Needed write capabilities for the context
+	     * @param aContextPublisher Interface to which the information whether
+	     * this context has subscribers or not is reported, can be also NULL.
+	     * @param aPublisherUid Secure UID of the process which registered
+	     * this context. Only process with the same SID is able to reregister
+	     * context in the purpose registering aContextPublisher.
+	     * @return None
+	     */
+        void DefineContextL( const TDesC& aContextSource,
+        	    const TDesC& aContextType,
+        	    const TSecurityPolicy& aReadSecurityPolicy,
+        	    const TSecurityPolicy& aWriteSecurityPolicy,
+        	    MCFContextSource* aContextPublisher,
+        	    const TUid& aPublisherUid );
+    
+        /**
+         * Publishes a new context object.
+         * The new context value is cached and needed indications
+         * for context subscribers are sent.
+         * Leaves with:
+         * - KErrNotFound, context not defined
+         * - KErrAccessDenied, insufficient capabilities to write the context
+         * 
+         * @since S60 5.0
+         * @param aContext New context object.
+         * @param aClientThread Handle to the current client.
+         * @return None.
+         */
+        void PublishContextL( CCFContextObject& aContext,
+            RThread& aClientThread );
+
+        /**
+         * Publishes a new context object.
+         * The new context value is cached and needed indications
+         * for context subscribers are sent.
+         * The data object is also sent to subscribers currently
+         * interested from the data.
+         * 
+         * @since S60 5.0
+         * @param aContext New context object.
+         * @param aClientThread Handle to the current client.
+         * @param aData Data object associated with the context.
+         * @return None.
+         */
+        void PublishContextL( CCFContextObject& aContext,
+            RThread& aClientThread,
+            CCFContextDataObject& aData );
+
+        /**
+         * Gets contexts of specified type.
+         * Tries to retrieve from cache the requested contexts using the given
+         * request (query) type. The requested context type can be partial
+         * ontology path.
+         *
+         * @param aResultBuffer Storage for the requested contexts.
+         * @param aContextQuery Settings for the request (query).
+         */
+        void RequestContextL(
+            RContextObjectArray& aResultBuffer,
+            CCFContextQuery& aContextQuery,
+            RThread& aClientThread );
+        
+        /**
+         * Requests specified context object.
+         * @param aContextType: Specifies the context type requested
+         * @param aContextSource: Specifies the context source
+         * @return CCFContextObject*
+         */
+        CCFContextObject* RequestContextL(
+            const TDesC& aContextType,
+            const TDesC& aContextSource,
+            RThread& aClientThread );
+
+		/**
+        *
+        * @since S60 5.0
+        * @param aParam1 Explanation.
+        * @param aParam2 Explanation.
+        * @return None
+        */    
+        void SubscribeContextL( CCFContextSubscription* aSubscription,
+    		MCFContextSubscriptionListener* aListener,
+    		RThread& aClientThread );
+
+		/**
+        *
+        * @since S60 5.0
+        * @param aParam1 Explanation.
+        * @param aParam2 Explanation.
+        * @return ETrue if cache element(s) was added to cleanup array
+        *   (subscription was nullified, not removed), EFalse otherwise.
+        */    
+        TBool RemoveSubscription( CCFContextSubscription& aSubscription,
+    		MCFContextSubscriptionListener& aListener );
+
+		/**
+        *
+        * @since S60 5.0
+        * @param aParam1 Explanation.
+        * @param aParam2 Explanation.
+        * @return ETrue if cache element(s) was added to cleanup array
+        *   (subscription(s) was nullified, not removed), EFalse otherwise.
+        */    
+        TBool RemoveSubscriptions(
+            MCFContextSubscriptionListener* aListener );
+
+        /**
+        * Cleanups context cache element's subscriptions by removing nullified
+        * subscriptions for all cache elements added to the cleanup array.
+        * 
+        * @since S60 5.0
+        * @return None.
+        */
+        void CleanupCacheElementSubscriptions();
+
+        /**
+ 		* Gets the read security policy of particular action.
+ 		*
+ 		* @param aContextSource Context Source.
+ 		* @param aContextType Context Type.
+ 		* @param aPolicy security policy which will be set by this method.
+ 		* @return None.
+ 		*/
+		void GetReadSecurityPolicyL( const TDesC& aContextSource,
+            const TDesC& aContextType,
+			TSecurityPolicy& aPolicy );
+		
+		/**
+		* Gets the write security policy of particular action.
+		*
+		* @param aContextSource Context Source.
+		* @param aContextType Context Type.
+		* @param aPolicy security policy which will be set by this method.
+		* @return None.
+		*/
+		void GetWriteSecurityPolicyL( const TDesC& aContextSource,
+	            const TDesC& aContextType,
+				TSecurityPolicy& aPolicy );
+        
+		/**
+		 * Deregister context publisher for all contexts it has been
+		 * registered as a publisher.
+		 * This has to be called before context publisher can be deleted.
+		 * @param aPublisher Publisher to be deregistered.
+		 */
+		void DeregisterPublisher( MCFContextSource& aPublisher );
+
+        /**
+         * Validates that the context can be published.
+         * Checks that the context is defined and the client has sufficient
+         * capabilities to write to the context.
+         * 
+         * Leaves with:
+         * - KErrNotFound, context not defined
+         * - KErrAccessDenied, insufficient capabilities to write the context
+         * 
+         * @since S60 5.0
+         * @param aContext New context object.
+         * @param aClientThread Handle to the current client.
+         * @return None.
+         */
+        void ValidatePublishContextL( CCFContextObject& aContext,
+            RThread& aClientThread );
+
+        /**
+         * Executes the actual publishing for the context.
+         * ValidatePublishContextL() must have been called before calling this
+         * because security is not checked by this function.
+         * 
+         * Leaves with:
+         * - KErrNotFound, context not defined
+         * - any other system-wide error code
+         * 
+         * @since S60 5.0
+         * @param aContext New context object.
+         * @param aData Data object associated with the context.
+         * @return None.
+         */
+        void DoPublishContextL( CCFContextObject& aContext,
+            CCFContextDataObject* aData = NULL );
+
+    private: // Constructors
+
+        CCFContextManager( MCFSecurityChecker& aSecurityChecker );
+        void ConstructL();
+
+    private: // New functions
+
+
+        // Notifies data manager that new subscription has been added.
+        void SubscriptionAddedL( CCFContextSubscriptionImpl& aSubscription,
+            RThread& aClientThread );
+        
+        // Notifies data manager that subscription has been removed.
+        // Returns value ETrue if cache element(s) was added to cleanup array,
+        // EFalse otherwise.
+        TBool SubscriptionRemoved( CCFContextSubscriptionImpl& aSubscription );
+
+        // Finalizes security check.        
+        TInt DoReadSecurityCheck( CCFCacheElement& aContextCache,
+        	    RThread& aClientThread );
+        
+        // Checks if the particular client has write access to particular
+        // cache element
+        TInt DoWriteSecurityCheck( CCFCacheElement& aContextCache,
+        	    RThread& aClientThread );
+
+        // Gets latest context values from context cache based on the specified
+        // query.
+        void GetLatestFromCacheL( 
+            RContextObjectArray& aLatestContexts, 
+            queryMatchFunction aMatchFunction, 
+            const CCFContextQueryImpl& aContextQuery,
+            RThread* aClientThread );
+            
+        // Logs context cache
+        void LogContextCache();
+
+        // Checks if the current client is from the same process
+        TBool RequestFromSameProcess( RThread& aClientThread );
+        
+        // Request contexts
+        void DoRequestContextL( RContextObjectArray& aResultBuffer,
+            CCFContextQuery& aContextQuery,
+            RThread* aClientThread );
+		    
+        // From MCFSubscriptionManager
+        void CacheElementAddedL( CCFCacheElement& aCacheElement );
+        
+        // Checks if context re-define is allowed
+        TBool RedefineAllowed( CCFCacheElement& aElement,
+            const MCFContextSource* aSource,
+            const TUid& aUid ) const;
+
+    private: // Member variables
+
+        // Previous context instance for subscriber indications.
+        CCFContextObject* iPreviousContext;
+
+        // Context cache.
+        RPointerArray<CCFCacheElement> iContextCache;
+
+        // A "linear order" instance.
+        TLinearOrder<CCFCacheElement>* iCacheOrder;
+
+        //
+        CCFCacheElement* iCacheSearchKey;
+        
+        // Own: Subscriptions
+        RPointerArray<CCFContextSubscriptionImpl> iSubscriptions;
+        
+        // Security checker interface.
+        MCFSecurityChecker* iSecurityChecker;
+
+        // Signals SubscriptionRemoved() that manager is in the middle of
+        // publishing context. Needed for context operations and context sources
+        // removing their subscriptions based on context indication, and doing
+        // it as a synchronous operation during the indication process.
+        // Not owned.
+        CCFCacheElement* iPublishingForCacheElement;
+
+        // Cleanup array for cache elements having nullified subscriptions,
+        // pointers are not owned.
+        RPointerArray< CCFCacheElement > iCleanupCacheElements;
+    };
+
+#endif  // C_CFCONTEXTMANAGER_H
+
+// End of File