flush

Forces a write of all user-space buffered data for the given this.

Will block during the operation. Closing the stream will implicitly cause a flush.

This function is optional for inherited classes.

If cancellable is not null, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error g_io_error_cancelled will be returned.

Parameters:

this	a OutputStream.
cancellable	optional cancellable object

Returns:

true on success, false on error