CleanupFile Event

Fires when the OS needs to clean up a file.


class CBFSCleanupFileEventParams {
  const QString &FileName();
  qint64 HandleInfo();
  void *FileContext();
  void *HandleContext();
  int ResultCode();
  void SetResultCode(int iResultCode);
  int EventRetVal();
  void SetEventRetVal(int iRetVal);
// To handle, connect one or more slots to this signal. void CleanupFile(CBFSCleanupFileEventParams *e);
// Or, subclass CBFS and override this emitter function. virtual int FireCleanupFile(CBFSCleanupFileEventParams *e) {...}


This event fires when the OS needs to close a handle to the currently-open file specified by FileName. This event differs from CloseFile in that CleanupFile fires immediately when an open handle to the specified file is closed by a process, whereas CloseFile may be fired much later when the OS itself decides that the file can be formally closed. (However, similar to CloseFile, this event will only fire for the last handle to a file if the FireAllOpenCloseEvents property is disabled.)

Other events may fire for the file handle in the time between when this event fires and when the CloseFile event fires. For example, system components such as the memory manager or cache manager may cause the ReadFile and WriteFile events to fire.

This event is optional; it is provided to give applications a chance to, e.g., free up resources associated with a file before it's formally closed.

When the FireAllOpenCloseEvents is set to false, this event is fired each time the file is closed by the application. When the file is opened and closed by some process multiple times consequently, the event handler can end up being called multiple times seemingly without a match with the OpenFile and CloseFile . However, such behavior is correct. The exact order of Open/Cleanup/Close events cannot be guaranteed due to the way Windows closes files.

The HandleInfo parameter carries a handle to an object with information about the file handle. While within the event handler, it can be used to call any of the following methods: GetHandleCreatorProcessId, GetHandleCreatorProcessName, GetHandleCreatorThreadId, or GetHandleCreatorToken.

The FileContext and HandleContext parameters are placeholders for application-defined data associated with the file and specific handle, respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource isn't available, security checks failed, etc.), set it to a non-zero value to report an appropriate error. Please refer to the Error Reporting and Handling topic for more information.

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CBFS Connect 2020 Qt Edition - Version 20.0 [Build 8348]