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