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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
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
from __future__ import absolute_import
import sys
import threading
from io import BytesIO
class LogThread(threading.Thread):
def __init__(self, queue, logger, level):
self.queue = queue
self.log_func = getattr(logger, level)
threading.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.log_func(msg)
class LoggingWrapper(BytesIO):
"""Wrapper for file like objects to redirect output to logger
instead"""
def __init__(self, queue, prefix=None):
BytesIO.__init__(self)
self.queue = queue
self.prefix = prefix
self.buffer = self
def write(self, data):
if isinstance(data, bytes):
try:
data = data.decode("utf8")
except UnicodeDecodeError:
data = data.decode("unicode_escape")
if data.endswith("\n"):
data = data[:-1]
if data.endswith("\r"):
data = data[:-1]
if not data:
return
if self.prefix is not None:
data = "%s: %s" % (self.prefix, data)
self.queue.put(data)
def flush(self):
pass
class CaptureIO(object):
def __init__(self, logger, do_capture, mp_context=None):
if mp_context is None:
import multiprocessing as mp_context
self.logger = logger
self.do_capture = do_capture
self.logging_queue = None
self.logging_thread = None
self.original_stdio = None
self.mp_context = mp_context
def __enter__(self):
if self.do_capture:
self.original_stdio = (sys.stdout, sys.stderr)
self.logging_queue = self.mp_context.Queue()
self.logging_thread = LogThread(self.logging_queue, self.logger, "info")
sys.stdout = LoggingWrapper(self.logging_queue, prefix="STDOUT")
sys.stderr = LoggingWrapper(self.logging_queue, prefix="STDERR")
self.logging_thread.start()
def __exit__(self, *args, **kwargs):
if self.do_capture:
sys.stdout, sys.stderr = self.original_stdio
if self.logging_queue is not None:
self.logger.info("Closing logging queue")
self.logging_queue.put(None)
if self.logging_thread is not None:
self.logging_thread.join(10)
while not self.logging_queue.empty():
try:
self.logger.warning(
"Dropping log message: %r", self.logging_queue.get()
)
except Exception:
pass
self.logging_queue.close()
self.logger.info("queue closed")