synapse-old/tests/util/test_file_consumer.py

194 lines
6.0 KiB
Python

# 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 io import BytesIO
from typing import BinaryIO, Generator, Optional, cast
from unittest.mock import NonCallableMock
from zope.interface import implementer
from twisted.internet import defer, reactor as _reactor
from twisted.internet.interfaces import IPullProducer
from synapse.types import ISynapseReactor
from synapse.util.file_consumer import BackgroundFileConsumer
from tests import unittest
reactor = cast(ISynapseReactor, _reactor)
class FileConsumerTests(unittest.TestCase):
@defer.inlineCallbacks
def test_pull_consumer(self) -> Generator["defer.Deferred[object]", object, None]:
string_file = BytesIO()
consumer = BackgroundFileConsumer(string_file, reactor=reactor)
try:
producer = DummyPullProducer()
yield producer.register_with_consumer(consumer)
yield producer.write_and_wait(b"Foo")
self.assertEqual(string_file.getvalue(), b"Foo")
yield producer.write_and_wait(b"Bar")
self.assertEqual(string_file.getvalue(), b"FooBar")
finally:
consumer.unregisterProducer()
yield consumer.wait() # type: ignore[misc]
self.assertTrue(string_file.closed)
@defer.inlineCallbacks
def test_push_consumer(self) -> Generator["defer.Deferred[object]", object, None]:
string_file = BlockingBytesWrite()
consumer = BackgroundFileConsumer(cast(BinaryIO, string_file), reactor=reactor)
try:
producer = NonCallableMock(spec_set=[])
consumer.registerProducer(producer, True)
consumer.write(b"Foo")
yield string_file.wait_for_n_writes(1) # type: ignore[misc]
self.assertEqual(string_file.buffer, b"Foo")
consumer.write(b"Bar")
yield string_file.wait_for_n_writes(2) # type: ignore[misc]
self.assertEqual(string_file.buffer, b"FooBar")
finally:
consumer.unregisterProducer()
yield consumer.wait() # type: ignore[misc]
self.assertTrue(string_file.closed)
@defer.inlineCallbacks
def test_push_producer_feedback(
self,
) -> Generator["defer.Deferred[object]", object, None]:
string_file = BlockingBytesWrite()
consumer = BackgroundFileConsumer(cast(BinaryIO, string_file), reactor=reactor)
try:
producer = NonCallableMock(spec_set=["pauseProducing", "resumeProducing"])
resume_deferred: defer.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(b"Foo")
number_writes += 1
producer.pauseProducing.assert_called_once()
yield string_file.wait_for_n_writes(number_writes) # type: ignore[misc]
yield resume_deferred
producer.resumeProducing.assert_called_once()
finally:
consumer.unregisterProducer()
yield consumer.wait() # type: ignore[misc]
self.assertTrue(string_file.closed)
@implementer(IPullProducer)
class DummyPullProducer:
def __init__(self) -> None:
self.consumer: Optional[BackgroundFileConsumer] = None
self.deferred: "defer.Deferred[object]" = defer.Deferred()
def resumeProducing(self) -> None:
d = self.deferred
self.deferred = defer.Deferred()
d.callback(None)
def stopProducing(self) -> None:
raise RuntimeError("Unexpected call")
def write_and_wait(self, write_bytes: bytes) -> "defer.Deferred[object]":
assert self.consumer is not None
d = self.deferred
self.consumer.write(write_bytes)
return d
def register_with_consumer(
self, consumer: BackgroundFileConsumer
) -> "defer.Deferred[object]":
d = self.deferred
self.consumer = consumer
self.consumer.registerProducer(self, False)
return d
class BlockingBytesWrite:
def __init__(self) -> None:
self.buffer = b""
self.closed = False
self.write_lock = threading.Lock()
self._notify_write_deferred: Optional[defer.Deferred] = None
self._number_of_writes = 0
def write(self, write_bytes: bytes) -> None:
with self.write_lock:
self.buffer += write_bytes
self._number_of_writes += 1
reactor.callFromThread(self._notify_write)
def close(self) -> None:
self.closed = True
def _notify_write(self) -> None:
"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: int
) -> Generator["defer.Deferred[object]", object, None]:
"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