loggingqueue module

class loggingqueue.QueueHandler(queue)

基类：logging.Handler

This handler sends events to a queue. Typically, it would be used together with a multiprocessing Queue to centralise logging to file in one process (in a multi-process application), so as to avoid file write contention between processes.

This code is new in Python 3.2, but this class can be copy pasted into user code for use with earlier Python versions.

emit(record)

Emit a record.

Writes the LogRecord to the queue, preparing it for pickling first.

enqueue(record)

Enqueue a record.

The base implementation uses put_nowait. You may want to override this method if you want to use blocking, timeouts or custom queue implementations.

prepare(record)

Prepares a record for queuing. The object returned by this method is enqueued.

The base implementation formats the record to merge the message and arguments, and removes unpickleable items from the record in-place.

You might want to override this method if you want to convert the record to a dict or JSON string, or send a modified copy of the record while leaving the original intact.

class loggingqueue.QueueListener(queue, *handlers)

基类：object

This class implements an internal threaded listener which watches for LogRecords being added to a queue, removes them and passes them to a list of handlers for processing.

dequeue(block)

Dequeue a record and return it, optionally blocking.

The base implementation uses get. You may want to override this method if you want to use timeouts or work with custom queue implementations.

enqueue_sentinel()

This is used to enqueue the sentinel record.

The base implementation uses put_nowait. You may want to override this method if you want to use timeouts or work with custom queue implementations.

handle(record)

Handle a record.

This just loops through the handlers offering them the record to handle.

prepare(record)

Prepare a record for handling.

This method just returns the passed-in record. You may want to override this method if you need to do any custom marshalling or manipulation of the record before passing it to the handlers.

start()

Start the listener.

This starts up a background thread to monitor the queue for LogRecords to process.

stop()

Stop the listener.

This asks the thread to terminate, and then waits for it to do so. Note that if you don’t call this before your application exits, there may be some records still left on the queue, which won’t be processed.