mirror of
https://github.com/quay/quay.git
synced 2026-01-27 18:42:52 +03:00
82 lines
2.5 KiB
Python
82 lines
2.5 KiB
Python
from multiprocessing import Process, Queue
|
|
from collections import namedtuple
|
|
|
|
import logging
|
|
import multiprocessing
|
|
import time
|
|
import sys
|
|
import traceback
|
|
|
|
|
|
logger = multiprocessing.log_to_stderr()
|
|
logger.setLevel(logging.INFO)
|
|
|
|
|
|
class QueueProcess(object):
|
|
"""
|
|
Helper class which invokes a worker in a process to produce data for one (or more) queues.
|
|
"""
|
|
|
|
def __init__(self, get_producer, chunk_size, max_size, args, finished=None):
|
|
self._get_producer = get_producer
|
|
self._queues = []
|
|
self._chunk_size = chunk_size
|
|
self._max_size = max_size
|
|
self._args = args or []
|
|
self._finished = finished
|
|
|
|
def create_queue(self):
|
|
"""
|
|
Adds a multiprocessing queue to the list of queues.
|
|
|
|
Any queues added will have the data produced appended.
|
|
"""
|
|
queue = Queue(self._max_size / self._chunk_size)
|
|
self._queues.append(queue)
|
|
return queue
|
|
|
|
@staticmethod
|
|
def run_process(target, args, finished=None):
|
|
def _target(tar, arg, fin):
|
|
try:
|
|
tar(*args)
|
|
finally:
|
|
if fin:
|
|
fin()
|
|
|
|
Process(target=_target, args=(target, args, finished)).start()
|
|
|
|
def run(self):
|
|
# Important! gipc is used here because normal multiprocessing does not work
|
|
# correctly with gevent when we sleep.
|
|
args = (self._get_producer, self._queues, self._chunk_size, self._args)
|
|
QueueProcess.run_process(_run, args, finished=self._finished)
|
|
|
|
|
|
QueueResult = namedtuple("QueueResult", ["data", "exception"])
|
|
|
|
|
|
def _run(get_producer, queues, chunk_size, args):
|
|
producer = get_producer(*args)
|
|
while True:
|
|
try:
|
|
result = QueueResult(producer(chunk_size) or None, None)
|
|
except Exception as ex:
|
|
message = "%s\n%s" % (ex.message, "".join(traceback.format_exception(*sys.exc_info())))
|
|
result = QueueResult(None, Exception(message))
|
|
|
|
for queue in queues:
|
|
try:
|
|
queue.put(result, block=True)
|
|
except Exception as ex:
|
|
logger.exception("Exception writing to queue.")
|
|
return
|
|
|
|
# Terminate the producer loop if the data produced is empty or an exception occurred.
|
|
if result.data is None or result.exception is not None:
|
|
break
|
|
|
|
# Important! This allows the thread that writes the queue data to the pipe
|
|
# to do so. Otherwise, this hangs.
|
|
time.sleep(0)
|