text: # -*- 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 synapse.metrics import InFlightGauge
  
  from tests import unittest
  
  
  def get_sample_labels_value(sample):
      """ Extract the labels and values of a sample.
  
      prometheus_client 0.5 changed the sample type to a named tuple with more
      members than the plain tuple had in 0.4 and earlier. This function can
      extract the labels and value from the sample for both sample types.
  
      Args:
          sample: The sample to get the labels and value from.
      Returns:
          A tuple of (labels, value) from the sample.
      """
  
      # If the sample has a labels and value attribute, use those.
      if hasattr(sample, "labels") and hasattr(sample, "value"):
          return sample.labels, sample.value
      # Otherwise fall back to treating it as a plain 3 tuple.
      else:
          _, labels, value = sample
          return labels, value
  
  
  class TestMauLimit(unittest.TestCase):
      def test_basic(self):
          gauge = InFlightGauge(
              "test1", "", labels=["test_label"], sub_metrics=["foo", "bar"]
          )
  
          def handle1(metrics):
              metrics.foo += 2
              metrics.bar = max(metrics.bar, 5)
  
          def handle2(metrics):
              metrics.foo += 3
              metrics.bar = max(metrics.bar, 7)
  
          gauge.register(("key1",), handle1)
  
          self.assert_dict(
              {
                  "test1_total": {("key1",): 1},
                  "test1_foo": {("key1",): 2},
                  "test1_bar": {("key1",): 5},
              },
              self.get_metrics_from_gauge(gauge),
          )
  
          gauge.unregister(("key1",), handle1)
  
          self.assert_dict(
              {
                  "test1_total": {("key1",): 0},
                  "test1_foo": {("key1",): 0},
                  "test1_bar": {("key1",): 0},
              },
              self.get_metrics_from_gauge(gauge),
          )
  
          gauge.register(("key1",), handle1)
          gauge.register(("key2",), handle2)
  
          self.assert_dict(
              {
                  "test1_total": {("key1",): 1, ("key2",): 1},
                  "test1_foo": {("key1",): 2, ("key2",): 3},
                  "test1_bar": {("key1",): 5, ("key2",): 7},
              },
              self.get_metrics_from_gauge(gauge),
          )
  
          gauge.unregister(("key2",), handle2)
          gauge.register(("key1",), handle2)
  
          self.assert_dict(
              {
                  "test1_total": {("key1",): 2, ("key2",): 0},
                  "test1_foo": {("key1",): 5, ("key2",): 0},
                  "test1_bar": {("key1",): 7, ("key2",): 0},
              },
              self.get_metrics_from_gauge(gauge),
          )
  
      def get_metrics_from_gauge(self, gauge):
          results = {}
  
          for r in gauge.collect():
              results[r.name] = {
                  tuple(labels[x] for x in gauge.labels): value
                  for labels, value in map(get_sample_labels_value, r.samples)
              }
  
          return results
  