NQE: Add default RTT and throughput observations

net/nqe/network_quality_estimator.h

 // 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.
 
 #ifndef NET_NQE_NETWORK_QUALITY_ESTIMATOR_H_
 #define NET_NQE_NETWORK_QUALITY_ESTIMATOR_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 280 matching lines @@
       nqe::internal::NetworkQualityStore::NetworkQualitiesCacheObserver*
           observer);
 
   // Called when the persistent prefs have been read. |read_prefs| contains the
   // parsed prefs as a map between NetworkIDs and CachedNetworkQualities.
   void OnPrefsRead(
       const std::map<nqe::internal::NetworkID,
                      nqe::internal::CachedNetworkQuality> read_prefs);
 
  protected:
+  // A protected constructor for testing that allows setting the value of
+  // |add_default_platform_observations_|.
+  NetworkQualityEstimator(
+      std::unique_ptr<ExternalEstimateProvider> external_estimates_provider,
+      const std::map<std::string, std::string>& variation_params,
+      bool use_local_host_requests_for_tests,
+      bool use_smaller_responses_for_tests,
+      bool add_default_platform_observations);
+
   // NetworkChangeNotifier::ConnectionTypeObserver implementation:
   void OnConnectionTypeChanged(
       NetworkChangeNotifier::ConnectionType type) override;
 
   // ExternalEstimateProvider::UpdatedEstimateObserver implementation.
   void OnUpdatedEstimateAvailable(const base::TimeDelta& rtt,
                                   int32_t downstream_throughput_kbps,
                                   int32_t upstream_throughput_kbps) override;
 
   // Returns true if median RTT at the HTTP layer is available and sets |rtt|
@@ skipping 45 matching lines @@
       const base::TimeTicks& start_time,
       base::TimeDelta* http_rtt,
       base::TimeDelta* transport_rtt,
       int32_t* downstream_throughput_kbps) const;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
                            AdaptiveRecomputationEffectiveConnectionType);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, StoreObservations);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestAddObservation);
-  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, ObtainOperatingParams);
+  FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
+                           DefaultObservationsOverridden);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
                            ObtainAlgorithmToUseFromParams);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, HalfLifeParam);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, ComputedPercentiles);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest, TestGetMetricsSince);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
                            TestExternalEstimateProviderMergeEstimates);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
                            UnknownEffectiveConnectionType);
   FRIEND_TEST_ALL_PREFIXES(NetworkQualityEstimatorTest,
@@ skipping 194 matching lines @@
 
   // Determines if the requests to local host can be used in estimating the
   // network quality. Set to true only for tests.
   bool use_localhost_requests_;
 
   // Determines if the responses smaller than |kMinTransferSizeInBytes|
   // or shorter than |kMinTransferSizeInBytes| can be used in estimating the
   // network quality. Set to true only for tests.
   bool use_small_responses_;
 
+  // If true, default values provided by the platform are used for estimation.
+  const bool add_default_platform_observations_;
+
   // The factor by which the weight of an observation reduces every second.
   const double weight_multiplier_per_second_;
 
   // Algorithm to use for computing effective connection type. The value is
   // obtained from field trial parameters. If the value from field trial
   // parameters is unavailable, it is set to
   // kDefaultEffectiveConnectionTypeAlgorithm.
   const EffectiveConnectionTypeAlgorithm effective_connection_type_algorithm_;
 
   // Tick clock used by the network quality estimator.
@@ skipping 21 matching lines @@
   // by timestamp.
   ThroughputObservationBuffer downstream_throughput_kbps_observations_;
 
   // Buffer that holds RTT observations sorted by timestamp.
   RttObservationBuffer rtt_observations_;
 
   // Default network quality observations obtained from the network quality
   // estimator field trial parameters. The observations are indexed by
   // ConnectionType.
   nqe::internal::NetworkQuality
-      default_observations_[NetworkChangeNotifier::CONNECTION_LAST];
+      default_observations_[NetworkChangeNotifier::CONNECTION_LAST + 1];

[bengr, 2016/11/29 18:39:15]

Why is this +1 now?

[tbansal1, 2016/12/02 17:41:17]

CONNECTION_LAST + 1 is correct. The size of the array should be 1 more than the
last connection type.

 
   // Thresholds for different effective connection types obtained from field
   // trial variation params. These thresholds encode how different connection
   // types behave in general. In future, complex encodings (e.g., curve
   // fitting) may be used.
   nqe::internal::NetworkQuality connection_thresholds_
       [EffectiveConnectionType::EFFECTIVE_CONNECTION_TYPE_LAST];
 
   // Typical network quality for different effective connection types.
   nqe::internal::NetworkQuality typical_network_quality_
@@ skipping 80 matching lines @@
   base::ThreadChecker thread_checker_;
 
   base::WeakPtrFactory<NetworkQualityEstimator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkQualityEstimator);
 };
 
 }  // namespace net
 
 #endif  // NET_NQE_NETWORK_QUALITY_ESTIMATOR_H_