Store network quality samples so we can compute percentiles.

net/base/network_quality.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_BASE_NETWORK_QUALITY_H_
 #define NET_BASE_NETWORK_QUALITY_H_
 
 #include <stdint.h>
 
 #include "base/time/time.h"
 
+namespace {
+
+// If two double values are within |kDelta| of each other, they are assumed to
+// be equal.
+const double kDelta = 0.001;
+
+}  // namespace
+
 namespace net {
 
 // API that is used to report the current network quality as estimated by the
 // NetworkQualityEstimator.
+// |rtt| is the estimate of the round trip time for the current connection.
+// |rtt_confidence| is the confidence of the |rtt| estimate.
+// |throughput_kbps| is the estimate of the Kbps for the current connection.
+// |throughput_kbps_confidence| is the confidence of the |throughput_kbps|
+// estimate.
 struct NET_EXPORT_PRIVATE NetworkQuality {
-  NetworkQuality(const base::TimeDelta& fastest_rtt,
-                 double fastest_rtt_confidence,
-                 uint64_t peak_throughput_kbps,
-                 double peak_throughput_kbps_confidence)
-      : fastest_rtt(fastest_rtt),
-        fastest_rtt_confidence(fastest_rtt_confidence),
-        peak_throughput_kbps(peak_throughput_kbps),
-        peak_throughput_kbps_confidence(peak_throughput_kbps_confidence) {}
+  NetworkQuality(const base::TimeDelta& rtt,
+                 double rtt_confidence,
+                 uint64_t throughput_kbps,
+                 double throughput_kbps_confidence)
+      : rtt(rtt),
+        rtt_confidence(rtt_confidence),
+        throughput_kbps(throughput_kbps),
+        throughput_kbps_confidence(throughput_kbps_confidence) {
+    DCHECK_GE(rtt, base::TimeDelta());
+    DCHECK_GE(rtt_confidence, 0 - kDelta);
+    DCHECK_LE(rtt_confidence, 1 + kDelta);
+
+    DCHECK_GE(throughput_kbps, 0U);
+    DCHECK_GE(throughput_kbps_confidence, 0 - kDelta);
+    DCHECK_LE(throughput_kbps_confidence, 1 + kDelta);

[mmenke, 2015/06/03 18:31:39]

Need base/logging.h (Which is weird to include in a header file, see next
comment)

[tbansal1, 2015/06/05 01:50:08]

Done.

+  }

[mmenke, 2015/06/03 18:31:39]

De-inline this constructor.  Inline constructors shouldn't involve much code
(And may be generally just a good idea to avoid them completely, anyways).

[tbansal1, 2015/06/05 01:50:08]

Done.

 
   ~NetworkQuality() {}
 
-  // The fastest round trip time observed for the current connection.
-  const base::TimeDelta fastest_rtt;
+  // The round trip time observed for the current connection.
+  const base::TimeDelta rtt;
 
-  // Confidence of the |fastest_rtt| estimate. Value lies between 0.0 and 1.0
+  // Confidence of the |rtt| estimate. Value lies between 0.0 and 1.0
   // with 0.0 being no confidence and 1.0 implying that estimates are same as
   // ground truth.
   // TODO(tbansal): Define units so values intermediate between 0.0 and 1.0 are
   // meaningful.
-  const double fastest_rtt_confidence;
+  const double rtt_confidence;
 
-  // Peak throughput in Kbps observed for the current connection.
-  const uint64_t peak_throughput_kbps;
+  // Throughput in Kbps observed for the current connection.
+  const uint64_t throughput_kbps;
 
-  // Confidence of the |peak_throughput_kbps| estimate. Value lies between 0.0
+  // Confidence of the |throughput_kbps| estimate. Value lies between 0.0
   // and 1.0 with 0.0 being no confidence and 1.0 implying that estimates are
   // same as ground truth.
   // TODO(tbansal): Define units so values intermediate between 0.0 and 1.0 are
   // meaningful.
-  const double peak_throughput_kbps_confidence;
+  const double throughput_kbps_confidence;
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_NETWORK_QUALITY_H_