One of two interfaces that must be implemented to provide
a custom logging implementation.
The XSQL Page Processor asks the
XSQLLoggerFactory associated with
each request to create() an instance of an
XSQLLogger to service the current request. If the factory implementation
returns the same XSQLLogger instance to multiple requests, the logger
implementation needs to be aware of this and synchronize access
to any resources used for logging as necessary.
Event handler method invoked by the XSQL page processing engine at
the start of the page request processing. The event only fires for
the top-level page request.