| // Copyright 2016 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_THROUGHPUT_ANALYZER_H_ |
| #define NET_NQE_THROUGHPUT_ANALYZER_H_ |
| |
| #include <stdint.h> |
| |
| #include <unordered_map> |
| #include <unordered_set> |
| |
| #include "base/callback.h" |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/sequence_checker.h" |
| #include "base/time/time.h" |
| #include "net/base/net_export.h" |
| #include "net/log/net_log_with_source.h" |
| |
| namespace { |
| typedef base::Callback<void(int32_t)> ThroughputObservationCallback; |
| } |
| |
| namespace base { |
| class SingleThreadTaskRunner; |
| class TickClock; |
| } |
| |
| namespace net { |
| |
| class NetworkQualityEstimatorParams; |
| class NetworkQualityEstimator; |
| class URLRequest; |
| |
| namespace nqe { |
| |
| namespace internal { |
| |
| // Makes throughput observations. Polls NetworkActivityMonitor |
| // (TrafficStats on Android) to count number of bits received over throughput |
| // observation windows in accordance with the following rules: |
| // (1) A new window of observation begins any time a URL request header is |
| // about to be sent, or a request completes or is destroyed. |
| // (2) A request is "active" if its headers are sent, but it hasn't completed, |
| // and "local" if destined to local host. If at any time during a |
| // throughput observation window there is an active, local request, the |
| // window is discarded. |
| // (3) If less than 32KB is received over the network during a window of |
| // observation, that window is discarded. |
| class NET_EXPORT_PRIVATE ThroughputAnalyzer { |
| public: |
| // |throughput_observation_callback| is called on the |task_runner| when |
| // |this| has a new throughput observation. |
| // |use_local_host_requests_for_tests| should only be true when testing |
| // against local HTTP server and allows the requests to local host to be |
| // used for network quality estimation. |use_smaller_responses_for_tests| |
| // should only be true when testing, and allows the responses smaller than |
| // |kMinTransferSizeInBits| or shorter than |
| // |kMinRequestDurationMicroseconds| to be used for network quality |
| // estimation. |
| // Virtualized for testing. |
| ThroughputAnalyzer( |
| const NetworkQualityEstimator* network_quality_estimator, |
| const NetworkQualityEstimatorParams* params, |
| scoped_refptr<base::SingleThreadTaskRunner> task_runner, |
| ThroughputObservationCallback throughput_observation_callback, |
| const base::TickClock* tick_clock, |
| const NetLogWithSource& net_log); |
| virtual ~ThroughputAnalyzer(); |
| |
| // Notifies |this| that the headers of |request| are about to be sent. |
| void NotifyStartTransaction(const URLRequest& request); |
| |
| // Notifies |this| that unfiltered bytes have been read for |request|. |
| void NotifyBytesRead(const URLRequest& request); |
| |
| // Notifies |this| that |request| has completed. |
| void NotifyRequestCompleted(const URLRequest& request); |
| |
| // Notifies |this| of a change in connection type. |
| void OnConnectionTypeChanged(); |
| |
| // |use_localhost_requests| should only be true when testing against local |
| // HTTP server and allows the requests to local host to be used for network |
| // quality estimation. |
| void SetUseLocalHostRequestsForTesting(bool use_localhost_requests); |
| |
| // Returns true if throughput is currently tracked by a throughput |
| // observation window. |
| bool IsCurrentlyTrackingThroughput() const; |
| |
| // Overrides the tick clock used by |this| for testing. |
| void SetTickClockForTesting(const base::TickClock* tick_clock); |
| |
| protected: |
| // Exposed for testing. |
| bool disable_throughput_measurements() const { |
| return disable_throughput_measurements_; |
| } |
| |
| // Returns the number of bits received by Chromium so far. The count may not |
| // start from zero, so the caller should only look at difference from a prior |
| // call. The count is obtained by polling TrafficStats on Android, and |
| // net::NetworkActivityMonitor on all other platforms. Virtualized for |
| // testing. |
| virtual int64_t GetBitsReceived() const; |
| |
| // Returns the number of in-flight requests that can be used for computing |
| // throughput. |
| size_t CountInFlightRequests() const; |
| |
| // Removes hanging requests from |requests_|. If any hanging requests are |
| // detected to be in-flight, the observation window is ended. Protected for |
| // testing. |
| void EraseHangingRequests(const URLRequest& request); |
| |
| // Returns true if the current throughput observation window is heuristically |
| // determined to contain hanging requests. |
| bool IsHangingWindow(int64_t bits_received, |
| base::TimeDelta duration, |
| double downstream_kbps_double) const; |
| |
| private: |
| friend class TestThroughputAnalyzer; |
| |
| // Mapping from URL request to the last time data was received for that |
| // request. |
| typedef std::unordered_map<const URLRequest*, base::TimeTicks> Requests; |
| |
| // Set of URL requests to hold the requests that reduce the accuracy of |
| // throughput computation. These requests are not used in throughput |
| // computation. |
| typedef std::unordered_set<const URLRequest*> AccuracyDegradingRequests; |
| |
| // Returns true if downstream throughput can be recorded. In that case, |
| // |downstream_kbps| is set to the computed downstream throughput (in |
| // kilobits per second). If a downstream throughput observation is taken, |
| // then the throughput observation window is reset so as to continue |
| // tracking throughput. A throughput observation can be taken only if the |
| // time-window is currently active, and enough bytes have accumulated in |
| // that window. |downstream_kbps| should not be null. |
| bool MaybeGetThroughputObservation(int32_t* downstream_kbps); |
| |
| // Starts the throughput observation window that keeps track of network |
| // bytes if the following conditions are true: |
| // (i) All active requests are non-local; |
| // (ii) There is at least one active, non-local request; and, |
| // (iii) The throughput observation window is not already tracking |
| // throughput. The window is started by setting the |start_| and |
| // |bits_received_|. |
| void MaybeStartThroughputObservationWindow(); |
| |
| // EndThroughputObservationWindow ends the throughput observation window. |
| void EndThroughputObservationWindow(); |
| |
| // Returns true if the |request| degrades the accuracy of the throughput |
| // observation window. A local request or a request that spans a connection |
| // change degrades the accuracy of the throughput computation. |
| bool DegradesAccuracy(const URLRequest& request) const; |
| |
| // Bounds |accuracy_degrading_requests_| and |requests_| to ensure their sizes |
| // do not exceed their capacities. |
| void BoundRequestsSize(); |
| |
| // Guaranteed to be non-null during the duration of |this|. |
| const NetworkQualityEstimator* network_quality_estimator_; |
| |
| // Guaranteed to be non-null during the duration of |this|. |
| const NetworkQualityEstimatorParams* params_; |
| |
| scoped_refptr<base::SingleThreadTaskRunner> task_runner_; |
| |
| // Called every time a new throughput observation is available. |
| ThroughputObservationCallback throughput_observation_callback_; |
| |
| // Guaranteed to be non-null during the lifetime of |this|. |
| const base::TickClock* tick_clock_; |
| |
| // Time when last connection change was observed. |
| base::TimeTicks last_connection_change_; |
| |
| // Start time of the current throughput observation window. Set to null if |
| // the window is not currently active. |
| base::TimeTicks window_start_time_; |
| |
| // Number of bits received prior to |start_| as reported by |
| // NetworkActivityMonitor. |
| int64_t bits_received_at_window_start_; |
| |
| // Container that holds active requests that reduce the accuracy of |
| // throughput computation. These requests are not used in throughput |
| // computation. |
| AccuracyDegradingRequests accuracy_degrading_requests_; |
| |
| // Container that holds active requests that do not reduce the accuracy of |
| // throughput computation. These requests are used in throughput computation. |
| Requests requests_; |
| |
| // Last time when the check for hanging requests was run. |
| base::TimeTicks last_hanging_request_check_; |
| |
| // If true, then |this| throughput analyzer stops tracking the throughput |
| // observations until Chromium is restarted. This may happen if the throughput |
| // analyzer has lost track of the requests that degrade throughput computation |
| // accuracy. |
| bool disable_throughput_measurements_; |
| |
| // 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_for_tests_; |
| |
| SEQUENCE_CHECKER(sequence_checker_); |
| |
| NetLogWithSource net_log_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ThroughputAnalyzer); |
| }; |
| |
| } // namespace internal |
| |
| } // namespace nqe |
| |
| } // namespace net |
| |
| #endif // NET_NQE_THROUGHPUT_ANALYZER_H_ |