Factor out NetworkID and caching mechanism from n_q_e.{h,cc}

net/nqe/network_quality_estimator_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/nqe/network_quality_estimator.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <limits>
@@ skipping 251 matching lines @@
       return accuracy_recording_intervals_;
 
     return NetworkQualityEstimator::GetAccuracyRecordingIntervals();
   }
 
   void set_rand_double(double rand_double) { rand_double_ = rand_double; }
 
   double RandDouble() const override { return rand_double_; }
 
   using NetworkQualityEstimator::SetTickClockForTesting;
-  using NetworkQualityEstimator::ReadCachedNetworkQualityEstimate;
   using NetworkQualityEstimator::OnConnectionTypeChanged;
 
  private:
   // NetworkQualityEstimator implementation that returns the overridden
   // network
   // id (instead of invoking platform APIs).
-  NetworkQualityEstimator::NetworkID GetCurrentNetworkID() const override {
-    return NetworkQualityEstimator::NetworkID(current_network_type_,
-                                              current_network_id_);
+  nqe::internal::NetworkID GetCurrentNetworkID() const override {
+    return nqe::internal::NetworkID(current_network_type_, current_network_id_);
   }
 
   bool effective_connection_type_set_;
   EffectiveConnectionType effective_connection_type_;
 
   bool recent_effective_connection_type_set_;
   EffectiveConnectionType recent_effective_connection_type_;
 
   NetworkChangeNotifier::ConnectionType current_network_type_;
   std::string current_network_id_;
@@ skipping 99 matching lines @@
 };
 
 }  // namespace
 
 TEST(NetworkQualityEstimatorTest, TestKbpsRTTUpdates) {
   base::HistogramTester histogram_tester;
   // Enable requests to local host to be used for network quality estimation.
   std::map<std::string, std::string> variation_params;
   TestNetworkQualityEstimator estimator(variation_params);
 
+  estimator.SimulateNetworkChangeTo(
+      NetworkChangeNotifier::ConnectionType::CONNECTION_UNKNOWN, "test");
+  histogram_tester.ExpectUniqueSample("NQE.CachedNetworkQualityAvailable",
+                                      false, 1);
+
   base::TimeDelta rtt;
   int32_t kbps;
   EXPECT_FALSE(estimator.GetHttpRTTEstimate(&rtt));
   EXPECT_FALSE(estimator.GetDownlinkThroughputKbpsEstimate(&kbps));
 
   TestDelegate test_delegate;
   TestURLRequestContext context(true);
   context.set_network_quality_estimator(&estimator);
   context.Init();
 
@@ skipping 20 matching lines @@
   std::unique_ptr<URLRequest> request2(context.CreateRequest(
       estimator.GetEchoURL(), DEFAULT_PRIORITY, &test_delegate));
   request2->SetLoadFlags(request2->load_flags() | LOAD_MAIN_FRAME);
   request2->Start();
   base::RunLoop().Run();
   histogram_tester.ExpectTotalCount(
       "NQE.MainFrame.EffectiveConnectionType.Unknown", 2);
 
   estimator.SimulateNetworkChangeTo(
       NetworkChangeNotifier::ConnectionType::CONNECTION_WIFI, "test-1");
+  histogram_tester.ExpectUniqueSample("NQE.CachedNetworkQualityAvailable",
+                                      false, 2);
   histogram_tester.ExpectTotalCount("NQE.PeakKbps.Unknown", 1);
   histogram_tester.ExpectTotalCount("NQE.FastestRTT.Unknown", 1);
 
   histogram_tester.ExpectTotalCount("NQE.RatioMedianRTT.WiFi", 0);
 
   histogram_tester.ExpectTotalCount("NQE.RTT.Percentile0.Unknown", 1);
   histogram_tester.ExpectTotalCount("NQE.RTT.Percentile10.Unknown", 1);
   histogram_tester.ExpectTotalCount("NQE.RTT.Percentile50.Unknown", 1);
   histogram_tester.ExpectTotalCount("NQE.RTT.Percentile90.Unknown", 1);
   histogram_tester.ExpectTotalCount("NQE.RTT.Percentile100.Unknown", 1);
 
   histogram_tester.ExpectTotalCount("NQE.TransportRTT.Percentile50.Unknown", 0);
 
   EXPECT_FALSE(estimator.GetHttpRTTEstimate(&rtt));
   EXPECT_FALSE(estimator.GetDownlinkThroughputKbpsEstimate(&kbps));
 
   // Verify that metrics are logged correctly on main-frame requests.
   histogram_tester.ExpectTotalCount("NQE.MainFrame.RTT.Percentile50.Unknown",
                                     1);
   histogram_tester.ExpectTotalCount(
       "NQE.MainFrame.TransportRTT.Percentile50.Unknown", 0);
   histogram_tester.ExpectTotalCount("NQE.MainFrame.Kbps.Percentile50.Unknown",
                                     1);
 
   estimator.SimulateNetworkChangeTo(
       NetworkChangeNotifier::ConnectionType::CONNECTION_WIFI, std::string());
+  histogram_tester.ExpectUniqueSample("NQE.CachedNetworkQualityAvailable",
+                                      false, 3);
   histogram_tester.ExpectTotalCount("NQE.PeakKbps.Unknown", 1);
   histogram_tester.ExpectTotalCount("NQE.FastestRTT.Unknown", 1);
 
   EXPECT_FALSE(estimator.GetHttpRTTEstimate(&rtt));
   EXPECT_FALSE(estimator.GetDownlinkThroughputKbpsEstimate(&kbps));
 
   std::unique_ptr<URLRequest> request3(context.CreateRequest(
       estimator.GetEchoURL(), DEFAULT_PRIORITY, &test_delegate));
   request3->SetLoadFlags(request2->load_flags() | LOAD_MAIN_FRAME);
   request3->Start();
   base::RunLoop().Run();
   histogram_tester.ExpectUniqueSample(
       "NQE.MainFrame.EffectiveConnectionType.WiFi",
       NetworkQualityEstimator::EffectiveConnectionType::
           EFFECTIVE_CONNECTION_TYPE_UNKNOWN,
       1);
+
+  estimator.SimulateNetworkChangeTo(
+      NetworkChangeNotifier::ConnectionType::CONNECTION_UNKNOWN, "test");
+  histogram_tester.ExpectBucketCount("NQE.CachedNetworkQualityAvailable", false,
+                                     3);
+  histogram_tester.ExpectBucketCount("NQE.CachedNetworkQualityAvailable", true,
+                                     1);
 }
 
 TEST(NetworkQualityEstimatorTest, StoreObservations) {
   std::map<std::string, std::string> variation_params;
   TestNetworkQualityEstimator estimator(variation_params);
 
   base::TimeDelta rtt;
   int32_t kbps;
   EXPECT_FALSE(estimator.GetHttpRTTEstimate(&rtt));
   EXPECT_FALSE(estimator.GetDownlinkThroughputKbpsEstimate(&kbps));
@@ skipping 486 matching lines @@
 
   for (const auto& test : tests) {
     variation_params["HalfLifeSeconds"] = test.variation_params_value;
     TestNetworkQualityEstimator estimator(variation_params);
     EXPECT_NEAR(test.expected_weight_multiplier,
                 estimator.weight_multiplier_per_second_, 0.001)
         << test.description;
   }
 }
 
-// Test if the network estimates are cached when network change notification
-// is invoked.
-TEST(NetworkQualityEstimatorTest, TestCaching) {
-  std::map<std::string, std::string> variation_params;
-  TestNetworkQualityEstimator estimator(variation_params);
-  size_t expected_cache_size = 0;
-  EXPECT_EQ(expected_cache_size, estimator.cached_network_qualities_.size());
-
-  // Cache entry will not be added for (NONE, "").
-  estimator.downstream_throughput_kbps_observations_.AddObservation(
-      NetworkQualityEstimator::ThroughputObservation(
-          1, base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-  estimator.rtt_observations_.AddObservation(
-      NetworkQualityEstimator::RttObservation(
-          base::TimeDelta::FromMilliseconds(1000), base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_2G, "test-1");
-  EXPECT_EQ(expected_cache_size, estimator.cached_network_qualities_.size());
-
-  // Entry will be added for (2G, "test1").
-  // Also, set the network quality for (2G, "test1") so that it is stored in
-  // the cache.
-  estimator.downstream_throughput_kbps_observations_.AddObservation(
-      NetworkQualityEstimator::ThroughputObservation(
-          1, base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-  estimator.rtt_observations_.AddObservation(
-      NetworkQualityEstimator::RttObservation(
-          base::TimeDelta::FromMilliseconds(1000), base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_3G, "test-1");
-  ++expected_cache_size;
-  EXPECT_EQ(expected_cache_size, estimator.cached_network_qualities_.size());
-
-  // Entry will be added for (3G, "test1").
-  // Also, set the network quality for (3G, "test1") so that it is stored in
-  // the cache.
-  estimator.downstream_throughput_kbps_observations_.AddObservation(
-      NetworkQualityEstimator::ThroughputObservation(
-          2, base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-  estimator.rtt_observations_.AddObservation(
-      NetworkQualityEstimator::RttObservation(
-          base::TimeDelta::FromMilliseconds(500), base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_3G, "test-2");
-  ++expected_cache_size;
-  EXPECT_EQ(expected_cache_size, estimator.cached_network_qualities_.size());
-
-  // Entry will not be added for (3G, "test2").
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_2G, "test-1");
-  EXPECT_EQ(expected_cache_size, estimator.cached_network_qualities_.size());
-
-  // Read the network quality for (2G, "test-1").
-  EXPECT_TRUE(estimator.ReadCachedNetworkQualityEstimate());
-
-  base::TimeDelta rtt;
-  int32_t kbps;
-  EXPECT_TRUE(estimator.GetHttpRTTEstimate(&rtt));
-  EXPECT_TRUE(estimator.GetDownlinkThroughputKbpsEstimate(&kbps));
-  EXPECT_EQ(1, kbps);
-  EXPECT_EQ(base::TimeDelta::FromMilliseconds(1000), rtt);
-  EXPECT_FALSE(estimator.GetTransportRTTEstimate(&rtt));
-
-  // No new entry should be added for (2G, "test-1") since it already exists
-  // in the cache.
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_3G, "test-1");
-  EXPECT_EQ(expected_cache_size, estimator.cached_network_qualities_.size());
-
-  // Read the network quality for (3G, "test-1").
-  EXPECT_TRUE(estimator.ReadCachedNetworkQualityEstimate());
-  EXPECT_TRUE(estimator.GetHttpRTTEstimate(&rtt));
-  EXPECT_TRUE(estimator.GetDownlinkThroughputKbpsEstimate(&kbps));
-  EXPECT_EQ(2, kbps);
-  EXPECT_EQ(base::TimeDelta::FromMilliseconds(500), rtt);
-  // No new entry should be added for (3G, "test1") since it already exists
-  // in the cache.
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_3G, "test-2");
-  EXPECT_EQ(expected_cache_size, estimator.cached_network_qualities_.size());
-
-  // Reading quality of (3G, "test-2") should return false.
-  EXPECT_FALSE(estimator.ReadCachedNetworkQualityEstimate());
-
-  // Reading quality of (2G, "test-3") should return false.
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_2G, "test-3");
-  EXPECT_FALSE(estimator.ReadCachedNetworkQualityEstimate());
-}
-
-// Tests if the cache size remains bounded. Also, ensure that the cache is
-// LRU.
-TEST(NetworkQualityEstimatorTest, TestLRUCacheMaximumSize) {
-  std::map<std::string, std::string> variation_params;
-  TestNetworkQualityEstimator estimator(variation_params);
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_WIFI, std::string());
-  EXPECT_EQ(0U, estimator.cached_network_qualities_.size());
-
-  // Add 100 more networks than the maximum size of the cache.
-  size_t network_count =
-      NetworkQualityEstimator::kMaximumNetworkQualityCacheSize + 100;
-
-  base::TimeTicks update_time_of_network_100;
-  for (size_t i = 0; i < network_count; ++i) {
-    estimator.downstream_throughput_kbps_observations_.AddObservation(
-        NetworkQualityEstimator::ThroughputObservation(
-            2, base::TimeTicks::Now(),
-            NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-    estimator.rtt_observations_.AddObservation(
-        NetworkQualityEstimator::RttObservation(
-            base::TimeDelta::FromMilliseconds(500), base::TimeTicks::Now(),
-            NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-
-    if (i == 100)
-      update_time_of_network_100 = base::TimeTicks::Now();
-
-    estimator.SimulateNetworkChangeTo(
-        NetworkChangeNotifier::ConnectionType::CONNECTION_WIFI,
-        base::SizeTToString(i));
-    if (i < NetworkQualityEstimator::kMaximumNetworkQualityCacheSize)
-      EXPECT_EQ(i, estimator.cached_network_qualities_.size());
-    EXPECT_LE(estimator.cached_network_qualities_.size(),
-              static_cast<size_t>(
-                  NetworkQualityEstimator::kMaximumNetworkQualityCacheSize));
-  }
-  // One more call so that the last network is also written to cache.
-  estimator.downstream_throughput_kbps_observations_.AddObservation(
-      NetworkQualityEstimator::ThroughputObservation(
-          2, base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-  estimator.rtt_observations_.AddObservation(
-      NetworkQualityEstimator::RttObservation(
-          base::TimeDelta::FromMilliseconds(500), base::TimeTicks::Now(),
-          NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST));
-  estimator.SimulateNetworkChangeTo(
-      NetworkChangeNotifier::ConnectionType::CONNECTION_WIFI,
-      base::SizeTToString(network_count - 1));
-  EXPECT_EQ(static_cast<size_t>(
-                NetworkQualityEstimator::kMaximumNetworkQualityCacheSize),
-            estimator.cached_network_qualities_.size());
-
-  // Test that the cache is LRU by examining its contents. Networks in cache
-  // must all be newer than the 100th network.
-  for (NetworkQualityEstimator::CachedNetworkQualities::iterator it =
-           estimator.cached_network_qualities_.begin();
-       it != estimator.cached_network_qualities_.end(); ++it) {
-    EXPECT_GE((it->second).last_update_time_, update_time_of_network_100);
-  }
-}
-
 TEST(NetworkQualityEstimatorTest, TestGetMetricsSince) {
   std::map<std::string, std::string> variation_params;
 
   const base::TimeDelta rtt_threshold_4g =
       base::TimeDelta::FromMilliseconds(30);
   const base::TimeDelta rtt_threshold_broadband =
       base::TimeDelta::FromMilliseconds(1);
 
   variation_params["4G.ThresholdMedianHttpRTTMsec"] =
       base::IntToString(rtt_threshold_4g.InMilliseconds());
@@ skipping 966 matching lines @@
 
     // Get the bits at index 18-24 which contain the resource fetch time.
     EXPECT_LE(0, (buckets.at(0).min >> kBitsPerMetric) % 128);
 
     // Get the bits at index 25-31 which contain the resource load size.
     EXPECT_LE(0, (buckets.at(0).min) % 128);
   }
 }
 
 }  // namespace net