synapse-old/tests/util/test_file_consumer.py

179 lines
4.9 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2018 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import threading
from mock import NonCallableMock
from six import StringIO
from twisted.internet import defer, reactor
from synapse.util.file_consumer import BackgroundFileConsumer
from tests import unittest
class FileConsumerTests(unittest.TestCase):
@defer.inlineCallbacks
def test_pull_consumer(self):
string_file = StringIO()
consumer = BackgroundFileConsumer(string_file, reactor=reactor)
try:
producer = DummyPullProducer()
yield producer.register_with_consumer(consumer)
yield producer.write_and_wait("Foo")
self.assertEqual(string_file.getvalue(), "Foo")
yield producer.write_and_wait("Bar")
self.assertEqual(string_file.getvalue(), "FooBar")
finally:
consumer.unregisterProducer()
yield consumer.wait()
self.assertTrue(string_file.closed)
@defer.inlineCallbacks
def test_push_consumer(self):
string_file = BlockingStringWrite()
consumer = BackgroundFileConsumer(string_file, reactor=reactor)
try:
producer = NonCallableMock(spec_set=[])
consumer.registerProducer(producer, True)
consumer.write("Foo")
yield string_file.wait_for_n_writes(1)
self.assertEqual(string_file.buffer, "Foo")
consumer.write("Bar")
yield string_file.wait_for_n_writes(2)
self.assertEqual(string_file.buffer, "FooBar")
finally:
consumer.unregisterProducer()
yield consumer.wait()
self.assertTrue(string_file.closed)
@defer.inlineCallbacks
def test_push_producer_feedback(self):
string_file = BlockingStringWrite()
consumer = BackgroundFileConsumer(string_file, reactor=reactor)
try:
producer = NonCallableMock(spec_set=["pauseProducing", "resumeProducing"])
resume_deferred = defer.Deferred()
producer.resumeProducing.side_effect = lambda: resume_deferred.callback(
None
)
consumer.registerProducer(producer, True)
number_writes = 0
with string_file.write_lock:
for _ in range(consumer._PAUSE_ON_QUEUE_SIZE):
consumer.write("Foo")
number_writes += 1
producer.pauseProducing.assert_called_once()
yield string_file.wait_for_n_writes(number_writes)
yield resume_deferred
producer.resumeProducing.assert_called_once()
finally:
consumer.unregisterProducer()
yield consumer.wait()
self.assertTrue(string_file.closed)
class DummyPullProducer(object):
def __init__(self):
self.consumer = None
self.deferred = defer.Deferred()
def resumeProducing(self):
d = self.deferred
self.deferred = defer.Deferred()
d.callback(None)
def write_and_wait(self, bytes):
d = self.deferred
self.consumer.write(bytes)
return d
def register_with_consumer(self, consumer):
d = self.deferred
self.consumer = consumer
self.consumer.registerProducer(self, False)
return d
class BlockingStringWrite(object):
def __init__(self):
self.buffer = ""
self.closed = False
self.write_lock = threading.Lock()
self._notify_write_deferred = None
self._number_of_writes = 0
def write(self, bytes):
with self.write_lock:
self.buffer += bytes
self._number_of_writes += 1
reactor.callFromThread(self._notify_write)
def close(self):
self.closed = True
def _notify_write(self):
"Called by write to indicate a write happened"
with self.write_lock:
if not self._notify_write_deferred:
return
d = self._notify_write_deferred
self._notify_write_deferred = None
d.callback(None)
@defer.inlineCallbacks
def wait_for_n_writes(self, n):
"Wait for n writes to have happened"
while True:
with self.write_lock:
if n <= self._number_of_writes:
return
if not self._notify_write_deferred:
self._notify_write_deferred = defer.Deferred()
d = self._notify_write_deferred
yield d