content/browser/geolocation/wifi_polling_policy.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_GEOLOCATION_WIFI_POLLING_POLICY_H_
   6 #define CONTENT_BROWSER_GEOLOCATION_WIFI_POLLING_POLICY_H_
   7
   8 namespace content {
   9
  10 // Allows sharing and mocking of the update polling policy function.
  11 class WifiPollingPolicy {
  12  public:
  13   WifiPollingPolicy() {}
  14   virtual ~WifiPollingPolicy() {}
  15   // Calculates the new polling interval for wiFi scans, given the previous
  16   // interval and whether the last scan produced new results.
  17   virtual void UpdatePollingInterval(bool scan_results_differ) = 0;
  18   virtual int PollingInterval() = 0;
  19   virtual int NoWifiInterval() = 0;
  20
  21  private:
  22   DISALLOW_COPY_AND_ASSIGN(WifiPollingPolicy);
  23 };
  24
  25 // Generic polling policy, constants are compile-time parameterized to allow
  26 // tuning on a per-platform basis.
  27 template<int DEFAULT_INTERVAL,
  28          int NO_CHANGE_INTERVAL,
  29          int TWO_NO_CHANGE_INTERVAL,
  30          int NO_WIFI_INTERVAL>
  31 class GenericWifiPollingPolicy : public WifiPollingPolicy {
  32  public:
  33   GenericWifiPollingPolicy() : polling_interval_(DEFAULT_INTERVAL) {}
  34   // WifiPollingPolicy
  35   void UpdatePollingInterval(bool scan_results_differ) override {
  36     if (scan_results_differ) {
  37       polling_interval_ = DEFAULT_INTERVAL;
  38     } else if (polling_interval_ == DEFAULT_INTERVAL) {
  39       polling_interval_ = NO_CHANGE_INTERVAL;
  40     } else {
  41       DCHECK(polling_interval_ == NO_CHANGE_INTERVAL ||
  42              polling_interval_ == TWO_NO_CHANGE_INTERVAL);
  43       polling_interval_ = TWO_NO_CHANGE_INTERVAL;
  44     }
  45   }
  46   int PollingInterval() override { return polling_interval_; }
  47   int NoWifiInterval() override { return NO_WIFI_INTERVAL; }
  48
  49  private:
  50   int polling_interval_;
  51 };
  52
  53 }  // namespace content
  54
  55 #endif  // CONTENT_BROWSER_GEOLOCATION_WIFI_POLLING_POLICY_H_