CBFS Connect 2020 Python Edition

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fire_all_open_close_events Property

Whether to fire events for all file open/close operations, or just the first and last.

Syntax

def get_fire_all_open_close_events() -> bool: ...
def set_fire_all_open_close_events(value: bool) -> None: ...

fire_all_open_close_events = property(get_fire_all_open_close_events, set_fire_all_open_close_events)

Default Value

FALSE

Remarks

This property specifies when the class should fire the on_create_file/on_open_file and on_cleanup_file/on_close_file events.

When this property is disabled (default), the class won't fire on_create_file/on_open_file for a file if there is already another handle open for it. Similarly, the on_cleanup_file/on_close_file events won't be fired unless the handle being closed is the last handle open for the file in question. This behavior results in better overall performance since the number of event firings is minimized, but there are some drawbacks as well:

  • If the file is only opened for reading initially, and then another process opens it for writing, the application won't be notified about the new mode, and may not be prepared to respond to the "unexpected" on_write_file events that will arrive should the second process start writing to the file. (Such an application may be able to mitigate this issue by always opening the file data from the backend store in read-write mode.)
  • The HandleInfo parameter of various events has no effect; they carry handle-specific information that isn't accessible to the application if this property is disabled.

When this property is enabled, the class fires the on_create_file/on_open_file and on_cleanup_file/on_close_file events every time a file handle is opened or closed.

This table shows when events will fire based on how this property is set:

Operation on FileDisabledEnabled
1. Opened by process A X X
2. Opened by process B X
3. Closed by process B X
4. Opened by process C X
5. Closed by process A X
6. Closed by process C X X

Note: This property cannot be changed after a virtual drive is created, and cannot be changed within events.

 
 
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CBFS Connect 2020 Python Edition - Version 20.0 [Build 7880]