userlibandfileserver/fileserver/inc/f32notification.h
changeset 0 a41df078684a
child 36 538db54a451d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/userlibandfileserver/fileserver/inc/f32notification.h	Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,313 @@
+// Copyright (c) 1995-2009 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: 
+// fileserver/inc/f32notification.h
+//
+
+#ifndef __F32NOTIFICATION_H__
+#define __F32NOTIFICATION_H__
+
+/*
+ * This class is not intended for instantiation neither on the stack
+ * nor on the heap.
+ * 
+ * Clients wishing to use this class should use a pointer provided by 
+ * CFsNotify::NextNotification().
+ * 
+ * @publishedAll
+ * @released
+ */
+class TFsNotification
+	{
+public:
+	enum TFsNotificationType
+		{
+		EFileChange		= 0x0001,	// File contents have changed or/and file has changed size
+		ERename 		= 0x0002,	// File/directory renamed, or file replaced using RFs::Replace()
+		ECreate 		= 0x0004,	// File/directory created, or file recreated using RFile::Replace()
+		EAttribute 		= 0x0008,	// File attribute(s) changed
+		EDelete 		= 0x0010, 	// File/directory deleted
+		EVolumeName		= 0x0020, 	// Volume name modified
+		EDriveName		= 0x0040, 	// Drive name modified
+		EMediaChange 	= 0x0080, 	// File system mounted/dismounted, media inserted/removed or device formatted
+		EOverflow		= 0x0100,	// Sent by the file server to notify when a buffer overflow occurs
+		EAllOps 		= KMaxTUint
+		};
+
+	/*
+	 * Any data returned is only valid after the previous asynchronous call to RequestNotifications has
+	 * completed and before the next call to RequestNotifications. 
+	 * 
+	 * @returns the type of notification as TFsNotificationType.
+	 * @publishedAll
+	 * @released
+	 */
+	IMPORT_C TFsNotificationType NotificationType() const;
+	
+	/*
+	 * Returns via the aPath parameter
+	 * the path of the file or directory that this notification is notifying about.
+	 * 
+	 * Any data returned is only valid after the previous asynchronous call to RequestNotifications has
+	 * completed and before the next call to RequestNotifications. 
+	 * 
+	 * @returns KErrNone upon success, otherwise one of the system wide errors
+	 * @param aPath - TPtrC& which is assigned to the path that was changed as notified by this notification.
+	 * @publishedAll
+	 * @released
+	 */
+	IMPORT_C TInt Path(TPtrC& aPath) const;
+	
+	/*
+	 * Certain notification types such as Rename, can provide 2 paths.
+	 * The first path will be the file that has changed, whilst the second path
+	 * with be the new name. (New filename in the case of rename).
+	 * 
+	 * Any data returned is only valid after the previous asynchronous call to RequestNotifications has
+	 * completed and before the next call to RequestNotifications. 
+	 * 
+	 * @returns KErrNone upon success, else one of the system wide errors
+	 * @param aNewName - TPtrC& which is set to the newname as described.
+	 * @publishedAll
+	 * @released
+	 */
+	IMPORT_C TInt NewName(TPtrC& aNewName) const; 
+	
+	/*
+	 * Any data returned is only valid after the previous asynchronous call to RequestNotifications has
+	 * completed and before the next call to RequestNotifications. 
+	 * 
+	 * @returns KErrNone upon success, else one of the system wide error codes
+	 * @param aSetAtt - In the case of the NotificationType being EAttributes, for the path that was changed
+	 * 					aSetAtt will return the attributes that were set.
+	 * @param aClearAtt - In the case of the NotificationType being EAttributes,
+	 * 					  returns the attributes that were cleared.
+	 * @publishedAll
+	 * @released
+	 */
+	IMPORT_C TInt Attributes(TUint& aSetAtt,TUint& aClearAtt) const;
+	
+	/*
+	 * In the case of the file size having changed, such as in calls to file write and set size,
+	 * aSize returns the new size of the file.
+	 * 
+	 * Any data returned is only valid after the previous asynchronous call to RequestNotifications has
+	 * completed and before the next call to RequestNotifications. 
+	 * 
+	 * @returns KErrNone upon success, else one of the system wide error codes
+	 * @param aSize - The new size of the file being notified about.
+	 * @publishedAll
+	 * @released
+	 */
+	IMPORT_C TInt FileSize(TInt64& aSize) const; 
+
+	/*
+	 * @returns The Drive Number associated with the Path.
+	IMPORT_C TInt DriveNumber(TInt& aDriveNumber) const;
+	 */
+	
+	/*
+	 * @returns the UID of the process that caused this change.
+	IMPORT_C TInt UID(TUid& aUID) const;
+	 */
+private:
+	//Declared private to prevent construction
+	TFsNotification();
+	~TFsNotification();
+	//To prevent copying.  No implementation is provided.
+	TFsNotification& operator=(TFsNotification& aNotification);
+	
+	TInt PathSize() const;
+	TInt NewNameSize() const;
+	TInt NotificationSize() const;
+
+	friend class CFsNotify;
+	friend class CFsNotificationList;
+	};
+
+class RFsNotify; //incomplete decl
+class CFsNotifyBody; //incomplete decl
+
+/*
+ * CFsNotify encapsulates the client-side sub-session associated with
+ * the file server notification framework.
+ * 
+ * In order to recieve notifications of changes to a file system, a 
+ * client may use this class in order to set up notification 'filters' and
+ * request notifications.
+ * 
+ * Filters can be set for specific types of operations on specific (and wildcard) paths.
+ * 
+ * The difference between using this framework and RFs::NotifyChange is that
+ * this framework will provide significant performance improvements, especially so
+ * when operating on a large number of files.
+ * 
+ * In addition, this framework will provide verbose information about each
+ * change that occurs, meaning that from a user's perspective they no longer have
+ * to perform expensive directory scans in order to acertain what has changed.
+ *
+ * Notifications can also provide additional information:
+ * EFileChange provides the new file size
+ * ERename provide the new name of the affected file.
+ * EDriveName/EVolumeName provides the name of the drive which has changed
+ * EAttribute provides the attributes which were set and cleared on the affected file. 
+ * 
+ * @publishedAll
+ * @released
+ */
+class CFsNotify : public CBase
+	{
+	public:
+		
+		/*
+		 * Factory function. Creates a new CFsNotify and returns a pointer to it.
+		 *
+		 * If aBufferSize is greater than (KMaxTInt/2) then it will return KErrArgument.
+		 * If it is less than KMinNotificationBufferSize (approximately 1KB) then aBufferSize will be 
+		 * set to KMinNotificationBufferSize.
+		 * 
+		 * @param aFs - RFs session. Must be connected.
+		 * @param aBufferSize  - Size of buffer in which to store notification objects.
+		 * @return CFsNotify* - Pointer to newly created CFsNotify.
+		 * @publishedAll
+		 * @released
+		 */
+		IMPORT_C static CFsNotify* NewL(RFs& aFs, TInt aBufferSize);
+		
+		/*
+		 * CFsNotify Destructor.
+		 * @publishedAll
+		 * @released
+		 */
+		IMPORT_C virtual ~CFsNotify();
+
+		/*
+		 * Clients are able to set-up notifications for changes based on Notification filters.
+		 * 
+		 * Filters can be set according to the type of notification required and the path to monitor.
+		 * Notification types are set up as a bitmask of TFsNotification::TNotificationType.
+		 * 		e.g.  (TUint) TFsNotification::ECreate | TFsNotification::EFileChange
+		 * 
+		 * So long as clients have filters set for a particular drive, they will automatically
+		 * receive TFsNotification::EMediaChange notifications regardless 
+		 * of whether they are registered for EMediaChange or not.
+		 * This notification can be caused by media card removal, the file system being dismounted or 
+		 * the media being formatted.
+		 *
+		 * If clients set the EOverflow notification type then AddNotification will return an error.
+		 * The exception to this is when using EAllOps which is used as a convenience notification type
+		 * which matches all of the notification types.
+		 * 
+		 * aPath specifies which path should be monitored for changes.
+		 * aFilename specifies which filename should be monitored for changes.
+		 * 
+		 * Either aPath or aFilename may be zero-length strings:
+		 * 	If you want to match a specific filename in every directory, you can leave aPath blank.
+		 *	Leaving aFilename blank results in matching against aPath only (i.e. a directory).
+		 * 
+		 * '*' and '?' wild cards are allowed in the path and filename.
+		 * 
+		 * To match against:
+		 * Specified directory only : (This is the specified directly only, not its contents.)
+		 * 		- aPath 	== drive:\\[path\\]directory\\
+		 * 		  aFilename == 					(zero length descriptor)
+		 *
+		 * Specified file only : 
+		 * 		- aPath		== drive:\\[path\\]directory\\
+		 * 		  aFilename == file.txt (or *, *.*, or *.txt)
+		 *
+		 * To enable matching against directories recursively:
+		 * 		- aPath		== drive:\\[path\\]directory\\*    (NB: trailing * denotes directory recursion)
+		 * 		- aFilename == file.txt (or *, *.*, or *.txt)
+		 *
+		 * 
+		 * @param aNotificationType - A Bitmask of the type of change to be monitored for based on the values of TFsNotification::TNotifyType
+		 * @param aPath - The directory to monitor
+		 * @param aFilename - The filename to monitor
+		 * @return KErrNone upon success, else one of the system wide error codes
+		 * @publishedAll
+		 * @released 
+		 */
+		IMPORT_C TInt AddNotification(TUint aNotificationType, const TDesC& aPath, const TDesC& aFilename);
+		
+		/*
+		 * Remove Notifications will remove all of the filters that have been 
+		 * set by calls to AddNotification.
+		 * 
+		 * This does not cancel any ongoing requests, but any on going requests will not complete until
+		 * filters have been added via calls to AddNotification
+		 * @return KErrNone or a system-wide error code.
+		 * @publishedAll
+		 * @released
+		 */
+		IMPORT_C TInt RemoveNotifications();
+		
+		/*
+		 * This is an Asynchronous function.
+		 * 
+		 * RequestNotification will issue a notification request asynchronously.
+		 * When this request has completed, aStatus's value will be set something other than KRequestPending.
+		 * 
+		 * Completion means that at least 1 notification has been put in the notification buffer.
+		 * Clients should call NextNotification() until it returns NULL.
+		 * 
+		 * When all the notifications have been read, the client should call RequestNotifications to set up another request.
+		 * 
+		 * Notifications will continue to be stored by the file server 
+		 * until CancelNotifications is called, meaning that notifications that occur 
+		 * whilst the client is processing the current notifications are not lost.
+		 * @param aStatus - A TRequestStatus that shall be completed when the Asynchronous request is completed.
+		 * @return KErrNone or a system-wide error code.
+		 * @publishedAll
+		 * @released
+		 */
+		IMPORT_C TInt RequestNotifications(TRequestStatus& aStatus);
+		
+		/*
+		 * Cancels the outstanding Asynchronous notification request that was set up
+		 * in the call to RequestNotifications.
+		 * @param aStatus - The TRequestStatus that was used in the call to RequestNotification
+		 * @return KErrNone or a system-wide error code.
+		 * @publishedAll
+		 * @released
+		 */
+		IMPORT_C TInt CancelNotifications(TRequestStatus& aStatus);
+		
+		/*
+		 * Once a notification request has completed, the client should call
+		 * NextNotification in order to access the notifications that have been stored in a notification buffer.
+		 * 
+		 * NextNotification returns a pointer to a TFsNotification. Each TFsNotification
+		 * represents a single notification.
+		 * 
+		 * When NULL is returned, there are no more Notifications to read and RequestNotification must be called.
+		 * 
+		 * @return const TFsNotification* - A pointer to a notification
+		 * @publishedAll
+		 * @released
+		 */
+		IMPORT_C const TFsNotification * NextNotification();
+		
+	private:
+		// Allocates buffer.
+		void ConstructL(RFs& aFs,TInt aBufferSize);
+		CFsNotify();
+
+		//Hide internals
+		CFsNotifyBody* iBody;
+		
+		friend class RFsNotify;
+		};
+
+#endif //__F32NOTIFICATION_H__
+