# Copyright 2021 The Matrix.org Foundation C.I.C. # # 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 synapse.logging.context import make_deferred_yieldable from synapse.util.batching_queue import ( BatchingQueue, number_in_flight, number_of_keys, number_queued, ) from tests.server import get_clock from tests.unittest import TestCase class BatchingQueueTestCase(TestCase): def setUp(self): self.clock, hs_clock = get_clock() # We ensure that we remove any existing metrics for "test_queue". try: number_queued.remove("test_queue") number_of_keys.remove("test_queue") number_in_flight.remove("test_queue") except KeyError: pass self._pending_calls = [] self.queue = BatchingQueue("test_queue", hs_clock, self._process_queue) async def _process_queue(self, values): d = defer.Deferred() self._pending_calls.append((values, d)) return await make_deferred_yieldable(d) def _get_sample_with_name(self, metric, name) -> int: """For a prometheus metric get the value of the sample that has a matching "name" label. """ for sample in metric.collect()[0].samples: if sample.labels.get("name") == name: return sample.value self.fail("Found no matching sample") def _assert_metrics(self, queued, keys, in_flight): """Assert that the metrics are correct""" sample = self._get_sample_with_name(number_queued, self.queue._name) self.assertEqual( sample, queued, "number_queued", ) sample = self._get_sample_with_name(number_of_keys, self.queue._name) self.assertEqual(sample, keys, "number_of_keys") sample = self._get_sample_with_name(number_in_flight, self.queue._name) self.assertEqual( sample, in_flight, "number_in_flight", ) def test_simple(self): """Tests the basic case of calling `add_to_queue` once and having `_process_queue` return. """ self.assertFalse(self._pending_calls) queue_d = defer.ensureDeferred(self.queue.add_to_queue("foo")) self._assert_metrics(queued=1, keys=1, in_flight=1) # The queue should wait a reactor tick before calling the processing # function. self.assertFalse(self._pending_calls) self.assertFalse(queue_d.called) # We should see a call to `_process_queue` after a reactor tick. self.clock.pump([0]) self.assertEqual(len(self._pending_calls), 1) self.assertEqual(self._pending_calls[0][0], ["foo"]) self.assertFalse(queue_d.called) self._assert_metrics(queued=0, keys=0, in_flight=1) # Return value of the `_process_queue` should be propagated back. self._pending_calls.pop()[1].callback("bar") self.assertEqual(self.successResultOf(queue_d), "bar") self._assert_metrics(queued=0, keys=0, in_flight=0) def test_batching(self): """Test that multiple calls at the same time get batched up into one call to `_process_queue`. """ self.assertFalse(self._pending_calls) queue_d1 = defer.ensureDeferred(self.queue.add_to_queue("foo1")) queue_d2 = defer.ensureDeferred(self.queue.add_to_queue("foo2")) self._assert_metrics(queued=2, keys=1, in_flight=2) self.clock.pump([0]) # We should see only *one* call to `_process_queue` self.assertEqual(len(self._pending_calls), 1) self.assertEqual(self._pending_calls[0][0], ["foo1", "foo2"]) self.assertFalse(queue_d1.called) self.assertFalse(queue_d2.called) self._assert_metrics(queued=0, keys=0, in_flight=2) # Return value of the `_process_queue` should be propagated back to both. self._pending_calls.pop()[1].callback("bar") self.assertEqual(self.successResultOf(queue_d1), "bar") self.assertEqual(self.successResultOf(queue_d2), "bar") self._assert_metrics(queued=0, keys=0, in_flight=0) def test_queuing(self): """Test that we queue up requests while a `_process_queue` is being called. """ self.assertFalse(self._pending_calls) queue_d1 = defer.ensureDeferred(self.queue.add_to_queue("foo1")) self.clock.pump([0]) self.assertEqual(len(self._pending_calls), 1) # We queue up work after the process function has been called, testing # that they get correctly queued up. queue_d2 = defer.ensureDeferred(self.queue.add_to_queue("foo2")) queue_d3 = defer.ensureDeferred(self.queue.add_to_queue("foo3")) # We should see only *one* call to `_process_queue` self.assertEqual(len(self._pending_calls), 1) self.assertEqual(self._pending_calls[0][0], ["foo1"]) self.assertFalse(queue_d1.called) self.assertFalse(queue_d2.called) self.assertFalse(queue_d3.called) self._assert_metrics(queued=2, keys=1, in_flight=3) # Return value of the `_process_queue` should be propagated back to the # first. self._pending_calls.pop()[1].callback("bar1") self.assertEqual(self.successResultOf(queue_d1), "bar1") self.assertFalse(queue_d2.called) self.assertFalse(queue_d3.called) self._assert_metrics(queued=2, keys=1, in_flight=2) # We should now see a second call to `_process_queue` self.clock.pump([0]) self.assertEqual(len(self._pending_calls), 1) self.assertEqual(self._pending_calls[0][0], ["foo2", "foo3"]) self.assertFalse(queue_d2.called) self.assertFalse(queue_d3.called) self._assert_metrics(queued=0, keys=0, in_flight=2) # Return value of the `_process_queue` should be propagated back to the # second. self._pending_calls.pop()[1].callback("bar2") self.assertEqual(self.successResultOf(queue_d2), "bar2") self.assertEqual(self.successResultOf(queue_d3), "bar2") self._assert_metrics(queued=0, keys=0, in_flight=0) def test_different_keys(self): """Test that calls to different keys get processed in parallel.""" self.assertFalse(self._pending_calls) queue_d1 = defer.ensureDeferred(self.queue.add_to_queue("foo1", key=1)) self.clock.pump([0]) queue_d2 = defer.ensureDeferred(self.queue.add_to_queue("foo2", key=2)) self.clock.pump([0]) # We queue up another item with key=2 to check that we will keep taking # things off the queue. queue_d3 = defer.ensureDeferred(self.queue.add_to_queue("foo3", key=2)) # We should see two calls to `_process_queue` self.assertEqual(len(self._pending_calls), 2) self.assertEqual(self._pending_calls[0][0], ["foo1"]) self.assertEqual(self._pending_calls[1][0], ["foo2"]) self.assertFalse(queue_d1.called) self.assertFalse(queue_d2.called) self.assertFalse(queue_d3.called) self._assert_metrics(queued=1, keys=1, in_flight=3) # Return value of the `_process_queue` should be propagated back to the # first. self._pending_calls.pop(0)[1].callback("bar1") self.assertEqual(self.successResultOf(queue_d1), "bar1") self.assertFalse(queue_d2.called) self.assertFalse(queue_d3.called) self._assert_metrics(queued=1, keys=1, in_flight=2) # Return value of the `_process_queue` should be propagated back to the # second. self._pending_calls.pop()[1].callback("bar2") self.assertEqual(self.successResultOf(queue_d2), "bar2") self.assertFalse(queue_d3.called) # We should now see a call `_pending_calls` for `foo3` self.clock.pump([0]) self.assertEqual(len(self._pending_calls), 1) self.assertEqual(self._pending_calls[0][0], ["foo3"]) self.assertFalse(queue_d3.called) self._assert_metrics(queued=0, keys=0, in_flight=1) # Return value of the `_process_queue` should be propagated back to the # third deferred. self._pending_calls.pop()[1].callback("bar4") self.assertEqual(self.successResultOf(queue_d3), "bar4") self._assert_metrics(queued=0, keys=0, in_flight=0)