content/browser/geolocation/wifi_data_provider_chromeos.cc

   1 // Copyright (c) 2012 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 // Provides wifi scan API binding for chromeos, using proprietary APIs.
   6
   7 #include "content/browser/geolocation/wifi_data_provider_chromeos.h"
   8
   9 #include "base/bind.h"
  10 #include "base/strings/utf_string_conversions.h"
  11 #include "chromeos/network/geolocation_handler.h"
  12 #include "content/public/browser/browser_thread.h"
  13
  14 namespace content {
  15
  16 namespace {
  17
  18 // The time periods between successive polls of the wifi data.
  19 const int kDefaultPollingIntervalMilliseconds = 10 * 1000;  // 10s
  20 const int kNoChangePollingIntervalMilliseconds = 2 * 60 * 1000;  // 2 mins
  21 const int kTwoNoChangePollingIntervalMilliseconds = 10 * 60 * 1000;  // 10 mins
  22 const int kNoWifiPollingIntervalMilliseconds = 20 * 1000; // 20s
  23
  24 }  // namespace
  25
  26 WifiDataProviderChromeOs::WifiDataProviderChromeOs() : started_(false) {
  27 }
  28
  29 WifiDataProviderChromeOs::~WifiDataProviderChromeOs() {
  30 }
  31
  32 void WifiDataProviderChromeOs::StartDataProvider() {
  33   DCHECK(CalledOnClientThread());
  34
  35   DCHECK(polling_policy_ == NULL);
  36   polling_policy_.reset(
  37       new GenericWifiPollingPolicy<kDefaultPollingIntervalMilliseconds,
  38                                    kNoChangePollingIntervalMilliseconds,
  39                                    kTwoNoChangePollingIntervalMilliseconds,
  40                                    kNoWifiPollingIntervalMilliseconds>);
  41
  42   ScheduleStart();
  43 }
  44
  45 void WifiDataProviderChromeOs::StopDataProvider() {
  46   DCHECK(CalledOnClientThread());
  47
  48   polling_policy_.reset();
  49   ScheduleStop();
  50 }
  51
  52 bool WifiDataProviderChromeOs::GetData(WifiData* data) {
  53   DCHECK(CalledOnClientThread());
  54   DCHECK(data);
  55   *data = wifi_data_;
  56   return is_first_scan_complete_;
  57 }
  58
  59 void WifiDataProviderChromeOs::DoStartTaskOnUIThread() {
  60   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  61   DoWifiScanTaskOnUIThread();
  62 }
  63
  64 void WifiDataProviderChromeOs::DoWifiScanTaskOnUIThread() {
  65   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  66
  67   // This method could be scheduled after a ScheduleStop.
  68   if (!started_)
  69     return;
  70
  71   WifiData new_data;
  72
  73   if (GetAccessPointData(&new_data.access_point_data)) {
  74     client_loop()->PostTask(
  75         FROM_HERE,
  76         base::Bind(&WifiDataProviderChromeOs::DidWifiScanTask, this, new_data));
  77   } else {
  78     client_loop()->PostTask(
  79         FROM_HERE,
  80         base::Bind(&WifiDataProviderChromeOs::DidWifiScanTaskNoResults, this));
  81   }
  82 }
  83
  84 void WifiDataProviderChromeOs::DidWifiScanTaskNoResults() {
  85   DCHECK(CalledOnClientThread());
  86   // Schedule next scan if started (StopDataProvider could have been called
  87   // in between DoWifiScanTaskOnUIThread and this method).
  88   if (started_)
  89     ScheduleNextScan(polling_policy_->NoWifiInterval());
  90 }
  91
  92 void WifiDataProviderChromeOs::DidWifiScanTask(const WifiData& new_data) {
  93   DCHECK(CalledOnClientThread());
  94   bool update_available = wifi_data_.DiffersSignificantly(new_data);
  95   wifi_data_ = new_data;
  96   // Schedule next scan if started (StopDataProvider could have been called
  97   // in between DoWifiScanTaskOnUIThread and this method).
  98   if (started_) {
  99     polling_policy_->UpdatePollingInterval(update_available);
 100     ScheduleNextScan(polling_policy_->PollingInterval());
 101   }
 102
 103   if (update_available || !is_first_scan_complete_) {
 104     is_first_scan_complete_ = true;
 105     RunCallbacks();
 106   }
 107 }
 108
 109 void WifiDataProviderChromeOs::ScheduleNextScan(int interval) {
 110   DCHECK(CalledOnClientThread());
 111   DCHECK(started_);
 112   BrowserThread::PostDelayedTask(
 113       BrowserThread::UI,
 114       FROM_HERE,
 115       base::Bind(&WifiDataProviderChromeOs::DoWifiScanTaskOnUIThread, this),
 116       base::TimeDelta::FromMilliseconds(interval));
 117 }
 118
 119 void WifiDataProviderChromeOs::ScheduleStop() {
 120   DCHECK(CalledOnClientThread());
 121   DCHECK(started_);
 122   started_ = false;
 123 }
 124
 125 void WifiDataProviderChromeOs::ScheduleStart() {
 126   DCHECK(CalledOnClientThread());
 127   DCHECK(!started_);
 128   started_ = true;
 129   // Perform first scan ASAP regardless of the polling policy. If this scan
 130   // fails we'll retry at a rate in line with the polling policy.
 131   BrowserThread::PostTask(
 132       BrowserThread::UI,
 133       FROM_HERE,
 134       base::Bind(&WifiDataProviderChromeOs::DoStartTaskOnUIThread, this));
 135 }
 136
 137 bool WifiDataProviderChromeOs::GetAccessPointData(
 138     WifiData::AccessPointDataSet* result) {
 139   // If wifi isn't enabled, we've effectively completed the task.
 140   // Return true to indicate an empty access point list.
 141   if (!chromeos::NetworkHandler::Get()->geolocation_handler()->wifi_enabled())
 142     return true;
 143
 144   chromeos::WifiAccessPointVector access_points;
 145   int64 age_ms = 0;
 146   if (!chromeos::NetworkHandler::Get()->geolocation_handler()->
 147       GetWifiAccessPoints(&access_points, &age_ms)) {
 148     return false;
 149   }
 150   for (chromeos::WifiAccessPointVector::const_iterator i
 151            = access_points.begin();
 152        i != access_points.end(); ++i) {
 153     AccessPointData ap_data;
 154     ap_data.mac_address = base::ASCIIToUTF16(i->mac_address);
 155     ap_data.radio_signal_strength = i->signal_strength;
 156     ap_data.channel = i->channel;
 157     ap_data.signal_to_noise = i->signal_to_noise;
 158     ap_data.ssid = base::UTF8ToUTF16(i->ssid);
 159     result->insert(ap_data);
 160   }
 161   // If the age is significantly longer than our long polling time, assume the
 162   // data is stale and return false which will trigger a faster update.
 163   if (age_ms > kTwoNoChangePollingIntervalMilliseconds * 2)
 164     return false;
 165   return true;
 166 }
 167
 168 // static
 169 WifiDataProviderImplBase* WifiDataProvider::DefaultFactoryFunction() {
 170   return new WifiDataProviderChromeOs();
 171 }
 172
 173 }  // namespace content