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# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
from threading import Thread
from .structuredlog import StructuredLogger, get_default_logger
class ProxyLogger(object):
"""
A ProxyLogger behaves like a
:class:`mozlog.structuredlog.StructuredLogger`.
Each method and attribute access will be forwarded to the underlying
StructuredLogger.
RuntimeError will be raised when the default logger is not yet initialized.
"""
def __init__(self, component=None):
self.logger = None
self._component = component
def __getattr__(self, name):
if self.logger is None:
self.logger = get_default_logger(component=self._component)
if self.logger is None:
raise RuntimeError("Default logger is not initialized!")
return getattr(self.logger, name)
def get_proxy_logger(component=None):
"""
Returns a :class:`ProxyLogger` for the given component.
"""
return ProxyLogger(component)
class QueuedProxyLogger(StructuredLogger):
"""Logger that logs via a queue.
This is intended for multiprocessing use cases where there are
some subprocesses which want to share a log handler with the main thread,
without the overhead of having a multiprocessing lock for all logger
access."""
threads = {}
def __init__(self, logger, mp_context=None):
StructuredLogger.__init__(self, logger.name)
if mp_context is None:
import multiprocessing as mp_context
if logger.name not in self.threads:
self.threads[logger.name] = LogQueueThread(mp_context.Queue(), logger)
self.threads[logger.name].start()
self.queue = self.threads[logger.name].queue
def _handle_log(self, data):
self.queue.put(data)
class LogQueueThread(Thread):
def __init__(self, queue, logger):
self.queue = queue
self.logger = logger
Thread.__init__(self, name="Thread-Log")
self.daemon = True
def run(self):
while True:
try:
msg = self.queue.get()
except (EOFError, IOError):
break
if msg is None:
break
else:
self.logger._handle_log(msg)