OnFileFlush event/delegate/callback


Pascal    Plain C    C++ (DLL/Lib)    C++ (VCL)    C++ (.NET)    C#    VB.NET    Java 

SolFSStorage     See also    


This event is fired when storage buffers must be flushed to media.


    TSolFSFlushFileEvent = procedure( Sender : TObject; FileHandle : THandle; var Result : LongInt) of object;

[Plain C]
    typedef Error (__stdcall *SolFSFlushFileFunc)( LongWord UserData, Handle FileHandle);

[C++ (DLL/Lib)]
    typedef Error (__stdcall *SolFSFlushFileFunc)( LongWord UserData, Handle FileHandle);

[C++ (VCL)]
    typedef void (__closure *TSolFSFlushFileEvent)( System::TObject* Sender, Handle FileHandle, Error& Result);

[C++ (.NET)]
    public __delegate void SolFSFlushFileEvent( SolFSStorage* Sender, UInt32 FileHandle, Int32 __gc &Result);

    public void SolFSFlushFileEvent( SolFSStorage Sender, uint FileHandle, ref int Result);

    Sub SolFSFlushFileEvent( ByVal Sender As SolFSStorage, ByVal FileHandle As UInt32, ByRef Result As Int32)

    void ISolFSFileEvents.onFileFlush()


  • Sender - reference to the class that called the delegate/event handler.
  • FileHandle - Handle to the storage that needs to be flushed.
  • Result - out parameter (return value for DLL) where the application places the result of the operation. If you are working with file system, Win32 error code is a good candidate for placing to Result parameter. Otherwise you can use any other error codes, just be sure that 0 means success.
    [Java]See Description for details about error reporting in Java.

  • [Plain C] UserData - application-defined parameter which is specified when creating the storage and passed back to callback function.


This event is fired when storage buffers must be flushed to media. If you are working with file system, call FlushFileBuffers. If you are working with remote location, the event handler must transfer all storage data to the remote location. Stream classes in VCL and in .NET Framework have Flush method.

The callback/event handler must be set before the storage is opened.

You need to implement ISolFSFileEvents interface in your code and pass the object, that implements the events, to one of SolFSStorage constructors that accept storageEvents parameter.

ERROR REPORTING: In Java you can't return more than one parameter, so the natural way is to throw an exception. You can throw any exception, and this exception will be passed back to the code, which called one of CBFS Storage functions. So if you use callback mechanism and throw exception from within event handlers, be sure to wrap each call to CBFS Storage methods with try/catch.

See also

Information about callbacks (Operating System edition only)     OnFileCreate     OnFileWrite