Add Network Quality observer to NQE

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 42 matching lines @@
 
   // EffectiveConnectionTypeObserver implementation:
   void OnEffectiveConnectionTypeChanged(EffectiveConnectionType type) override {
     effective_connection_types_.push_back(type);
   }
 
  private:
   std::vector<EffectiveConnectionType> effective_connection_types_;
 };
 
+class TestNetworkQualityObserver
+    : public NetworkQualityEstimator::NetworkQualityObserver {
+ public:
+  TestNetworkQualityObserver()
+      : http_rtt_(nqe::internal::InvalidRTT()),
+        transport_rtt_(nqe::internal::InvalidRTT()),
+        downstream_throughput_kbps_(nqe::internal::kInvalidThroughput),
+        notifications_received_(0U) {}
+
+  // NetworkQualityObserver implementation:
+  void OnNetworkQualityChanged(base::TimeDelta http_rtt,
+                               base::TimeDelta transport_rtt,
+                               int32_t downstream_throughput_kbps) override {
+    http_rtt_ = http_rtt;
+    transport_rtt_ = transport_rtt;
+    downstream_throughput_kbps_ = downstream_throughput_kbps;
+    notifications_received_++;
+  }
+
+  size_t notifications_received() const { return notifications_received_; }
+
+  base::TimeDelta http_rtt() const { return http_rtt_; }
+  base::TimeDelta transport_rtt() const { return transport_rtt_; }
+  int32_t downstream_throughput_kbps() const {
+    return downstream_throughput_kbps_;
+  }
+
+ private:
+  base::TimeDelta http_rtt_;
+  base::TimeDelta transport_rtt_;
+  int32_t downstream_throughput_kbps_;
+  size_t notifications_received_;

[RyanSturm, 2016/10/11 01:46:26]

nit: Why size_t here and not int? There's not really a size since this isn't a
list of notifications for instance.

[tbansal1, 2016/10/11 17:46:12]

Done.

Not sure it matters though. From
https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++.md:
"Use size_t for object and allocation sizes, object counts, ..."

+};
+
 class TestRTTObserver : public NetworkQualityEstimator::RTTObserver {
  public:
   struct Observation {
     Observation(int32_t ms,
                 const base::TimeTicks& ts,
                 NetworkQualityObservationSource src)
         : rtt_ms(ms), timestamp(ts), source(src) {}
     int32_t rtt_ms;
     base::TimeTicks timestamp;
     NetworkQualityObservationSource source;
@@ skipping 1257 matching lines @@
                                   "test");
   EXPECT_EQ(2U, observer.effective_connection_types().size());
 
   // A change in effective connection type does not trigger notification to the
   // observers, since it is not accompanied by any new observation or a network
   // change event.
   estimator.set_recent_effective_connection_type(EFFECTIVE_CONNECTION_TYPE_3G);
   EXPECT_EQ(2U, observer.effective_connection_types().size());
 }
 
+// Tests that the network quality is computed at the specified interval, and
+// that the network quality observers are notified of any change.
+TEST(NetworkQualityEstimatorTest, TestNetworkQualityObserver) {
+  base::HistogramTester histogram_tester;
+  std::unique_ptr<base::SimpleTestTickClock> tick_clock(
+      new base::SimpleTestTickClock());
+  base::SimpleTestTickClock* tick_clock_ptr = tick_clock.get();
+
+  TestNetworkQualityObserver observer;
+  std::map<std::string, std::string> variation_params;
+  TestNetworkQualityEstimator estimator(variation_params);
+  estimator.AddNetworkQualityObserver(&observer);
+  estimator.SetTickClockForTesting(std::move(tick_clock));
+
+  TestDelegate test_delegate;
+  TestURLRequestContext context(true);
+  context.set_network_quality_estimator(&estimator);
+  context.Init();
+
+  EXPECT_EQ(nqe::internal::InvalidRTT(), observer.http_rtt());
+  EXPECT_EQ(nqe::internal::InvalidRTT(), observer.transport_rtt());
+  EXPECT_EQ(nqe::internal::kInvalidThroughput,
+            observer.downstream_throughput_kbps());
+  EXPECT_EQ(0U, observer.notifications_received());
+
+  base::TimeDelta http_rtt(base::TimeDelta::FromMilliseconds(100));
+  base::TimeDelta transport_rtt(base::TimeDelta::FromMilliseconds(200));
+  int32_t downstream_throughput_kbps(300);
+  estimator.set_recent_effective_connection_type(EFFECTIVE_CONNECTION_TYPE_2G);
+  estimator.set_recent_http_rtt(http_rtt);
+  estimator.set_recent_transport_rtt(transport_rtt);
+  estimator.set_recent_downlink_throughput_kbps(downstream_throughput_kbps);
+  tick_clock_ptr->Advance(base::TimeDelta::FromMinutes(60));
+
+  std::unique_ptr<URLRequest> request(context.CreateRequest(
+      estimator.GetEchoURL(), DEFAULT_PRIORITY, &test_delegate));
+  request->SetLoadFlags(request->load_flags() | LOAD_MAIN_FRAME_DEPRECATED);
+  request->Start();
+  base::RunLoop().Run();
+  EXPECT_EQ(http_rtt, observer.http_rtt());
+  EXPECT_EQ(transport_rtt, observer.transport_rtt());
+  EXPECT_EQ(downstream_throughput_kbps, observer.downstream_throughput_kbps());
+  EXPECT_EQ(1U, observer.notifications_received());
+
+  // Next request should not trigger recomputation of effective connection type
+  // since there has been no change in the clock.
+  std::unique_ptr<URLRequest> request2(context.CreateRequest(
+      estimator.GetEchoURL(), DEFAULT_PRIORITY, &test_delegate));
+  request2->SetLoadFlags(request->load_flags() | LOAD_MAIN_FRAME_DEPRECATED);
+  request2->Start();
+  base::RunLoop().Run();
+  EXPECT_EQ(1U, observer.notifications_received());
+
+  // Change in connection type should send out notification to the observers.
+  estimator.set_effective_connection_type(EFFECTIVE_CONNECTION_TYPE_3G);
+  estimator.SimulateNetworkChange(NetworkChangeNotifier::CONNECTION_WIFI,
+                                  "test");
+  EXPECT_EQ(2U, observer.notifications_received());
+
+  // A change in effective connection type does not trigger notification to the
+  // observers, since it is not accompanied by any new observation or a network
+  // change event.
+  estimator.set_recent_effective_connection_type(EFFECTIVE_CONNECTION_TYPE_3G);
+  EXPECT_EQ(2U, observer.notifications_received());
+}
+
 // Tests that the effective connection type is computed on every RTT
 // observation if the last computed effective connection type was unknown.
 TEST(NetworkQualityEstimatorTest, UnknownEffectiveConnectionType) {
   std::unique_ptr<base::SimpleTestTickClock> tick_clock(
       new base::SimpleTestTickClock());
   base::SimpleTestTickClock* tick_clock_ptr = tick_clock.get();
 
   TestEffectiveConnectionTypeObserver observer;
   std::map<std::string, std::string> variation_params;
   TestNetworkQualityEstimator estimator(variation_params);
@@ skipping 734 matching lines @@
     if (expected_count == 1) {
       EffectiveConnectionType last_notified_type =
           observer.effective_connection_types().at(
               observer.effective_connection_types().size() - 1);
       EXPECT_EQ(i, last_notified_type);
     }
   }
 }
 
 }  // namespace net