From bc67e7d260631d3fa7bc78653376e15dc0771364 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 17 Jan 2018 16:43:03 +0000 Subject: Add decent impl of a FileConsumer Twisted core doesn't have a general purpose one, so we need to write one ourselves. Features: - All writing happens in background thread - Supports both push and pull producers - Push producers get paused if the consumer falls behind --- tests/util/test_file_consumer.py | 138 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 tests/util/test_file_consumer.py (limited to 'tests/util') diff --git a/tests/util/test_file_consumer.py b/tests/util/test_file_consumer.py new file mode 100644 index 0000000000..8acb68f0c3 --- /dev/null +++ b/tests/util/test_file_consumer.py @@ -0,0 +1,138 @@ +# -*- 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. + + +from twisted.internet import defer +from mock import NonCallableMock + +from synapse.util.file_consumer import BackgroundFileConsumer + +from tests import unittest +from StringIO import StringIO + +import threading + + +class FileConsumerTests(unittest.TestCase): + + @defer.inlineCallbacks + def test_pull_consumer(self): + string_file = StringIO() + consumer = BackgroundFileConsumer(string_file) + + 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 = StringIO() + consumer = BackgroundFileConsumer(string_file) + + try: + producer = NonCallableMock(spec_set=[]) + + consumer.registerProducer(producer, True) + + consumer.write("Foo") + yield consumer.wait_for_writes() + + self.assertEqual(string_file.getvalue(), "Foo") + + consumer.write("Bar") + yield consumer.wait_for_writes() + + self.assertEqual(string_file.getvalue(), "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) + + try: + producer = NonCallableMock(spec_set=["pauseProducing", "resumeProducing"]) + + consumer.registerProducer(producer, True) + + with string_file.write_lock: + for _ in range(consumer._PAUSE_ON_QUEUE_SIZE): + consumer.write("Foo") + + producer.pauseProducing.assert_called_once() + + yield consumer.wait_for_writes() + 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() + + def write(self, bytes): + self.buffer += bytes + + def close(self): + self.closed = True -- cgit 1.4.1 From 1432f7ccd5a01e43d0c5417f3d2f4a6a0fbf5bfb Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Thu, 18 Jan 2018 11:53:21 +0000 Subject: Move test stuff to tests --- synapse/util/file_consumer.py | 26 +------------------ tests/util/test_file_consumer.py | 54 ++++++++++++++++++++++++++++++++++------ 2 files changed, 47 insertions(+), 33 deletions(-) (limited to 'tests/util') diff --git a/synapse/util/file_consumer.py b/synapse/util/file_consumer.py index d19d48665c..3241035247 100644 --- a/synapse/util/file_consumer.py +++ b/synapse/util/file_consumer.py @@ -13,7 +13,7 @@ # See the License for the specific language governing permissions and # limitations under the License. -from twisted.internet import defer, threads, reactor +from twisted.internet import threads, reactor from synapse.util.logcontext import make_deferred_yieldable @@ -57,10 +57,6 @@ class BackgroundFileConsumer(object): # If the _writer thread throws an exception it gets stored here. self._write_exception = None - # A deferred that gets resolved when the bytes_queue gets empty. - # Mainly used for tests. - self._notify_empty_deferred = None - def registerProducer(self, producer, streaming): """Part of IConsumer interface @@ -113,9 +109,6 @@ class BackgroundFileConsumer(object): if self._bytes_queue.qsize() <= self._RESUME_ON_QUEUE_SIZE: reactor.callFromThread(self._resume_paused_producer) - if self._notify_empty_deferred and self._bytes_queue.empty(): - reactor.callFromThread(self._notify_empty) - bytes = self._bytes_queue.get() # If we get a None (or empty list) then that's a signal used @@ -144,20 +137,3 @@ class BackgroundFileConsumer(object): if self._paused_producer and self._producer: self._paused_producer = False self._producer.resumeProducing() - - def _notify_empty(self): - """Called when the _writer thread thinks the queue may be empty and - we should notify anything waiting on `wait_for_writes` - """ - if self._notify_empty_deferred and self._bytes_queue.empty(): - d = self._notify_empty_deferred - self._notify_empty_deferred = None - d.callback(None) - - def wait_for_writes(self): - """Wait for the write queue to be empty and for writes to have - finished. This is mainly useful for tests. - """ - if not self._notify_empty_deferred: - self._notify_empty_deferred = defer.Deferred() - return self._notify_empty_deferred diff --git a/tests/util/test_file_consumer.py b/tests/util/test_file_consumer.py index 8acb68f0c3..76e2234255 100644 --- a/tests/util/test_file_consumer.py +++ b/tests/util/test_file_consumer.py @@ -14,7 +14,7 @@ # limitations under the License. -from twisted.internet import defer +from twisted.internet import defer, reactor from mock import NonCallableMock from synapse.util.file_consumer import BackgroundFileConsumer @@ -53,7 +53,7 @@ class FileConsumerTests(unittest.TestCase): @defer.inlineCallbacks def test_push_consumer(self): - string_file = StringIO() + string_file = BlockingStringWrite() consumer = BackgroundFileConsumer(string_file) try: @@ -62,14 +62,14 @@ class FileConsumerTests(unittest.TestCase): consumer.registerProducer(producer, True) consumer.write("Foo") - yield consumer.wait_for_writes() + yield string_file.wait_for_n_writes(1) - self.assertEqual(string_file.getvalue(), "Foo") + self.assertEqual(string_file.buffer, "Foo") consumer.write("Bar") - yield consumer.wait_for_writes() + yield string_file.wait_for_n_writes(2) - self.assertEqual(string_file.getvalue(), "FooBar") + self.assertEqual(string_file.buffer, "FooBar") finally: consumer.unregisterProducer() @@ -85,15 +85,22 @@ class FileConsumerTests(unittest.TestCase): 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 consumer.wait_for_writes() + yield string_file.wait_for_n_writes(number_writes) + + yield resume_deferred producer.resumeProducing.assert_called_once() finally: consumer.unregisterProducer() @@ -131,8 +138,39 @@ class BlockingStringWrite(object): self.closed = False self.write_lock = threading.Lock() + self._notify_write_deferred = None + self._number_of_writes = 0 + def write(self, bytes): - self.buffer += 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 -- cgit 1.4.1