content/browser/geolocation/wifi_data_provider_common.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 #include "content/browser/geolocation/wifi_data_provider_common.h"
   6
   7 #include "base/bind.h"
   8 #include "base/strings/stringprintf.h"
   9 #include "base/strings/utf_string_conversions.h"
  10
  11 namespace content {
  12
  13 base::string16 MacAddressAsString16(const uint8 mac_as_int[6]) {
  14   // mac_as_int is big-endian. Write in byte chunks.
  15   // Format is XX-XX-XX-XX-XX-XX.
  16   static const char* const kMacFormatString =
  17       "%02x-%02x-%02x-%02x-%02x-%02x";
  18   return base::ASCIIToUTF16(base::StringPrintf(kMacFormatString,
  19                                                mac_as_int[0],
  20                                                mac_as_int[1],
  21                                                mac_as_int[2],
  22                                                mac_as_int[3],
  23                                                mac_as_int[4],
  24                                                mac_as_int[5]));
  25 }
  26
  27 WifiDataProviderCommon::WifiDataProviderCommon()
  28     : is_first_scan_complete_(false),
  29       weak_factory_(this) {
  30 }
  31
  32 WifiDataProviderCommon::~WifiDataProviderCommon() {
  33 }
  34
  35 void WifiDataProviderCommon::StartDataProvider() {
  36   DCHECK(wlan_api_ == NULL);
  37   wlan_api_.reset(NewWlanApi());
  38   if (wlan_api_ == NULL) {
  39     // Error! Can't do scans, so don't try and schedule one.
  40     is_first_scan_complete_ = true;
  41     return;
  42   }
  43
  44   DCHECK(polling_policy_ == NULL);
  45   polling_policy_.reset(NewPollingPolicy());
  46   DCHECK(polling_policy_ != NULL);
  47
  48   // Perform first scan ASAP regardless of the polling policy. If this scan
  49   // fails we'll retry at a rate in line with the polling policy.
  50   ScheduleNextScan(0);
  51 }
  52
  53 void WifiDataProviderCommon::StopDataProvider() {
  54   wlan_api_.reset();
  55   polling_policy_.reset();
  56 }
  57
  58 bool WifiDataProviderCommon::GetData(WifiData* data) {
  59   *data = wifi_data_;
  60   // If we've successfully completed a scan, indicate that we have all of the
  61   // data we can get.
  62   return is_first_scan_complete_;
  63 }
  64
  65 void WifiDataProviderCommon::DoWifiScanTask() {
  66   bool update_available = false;
  67   WifiData new_data;
  68   if (!wlan_api_->GetAccessPointData(&new_data.access_point_data)) {
  69     ScheduleNextScan(polling_policy_->NoWifiInterval());
  70   } else {
  71     update_available = wifi_data_.DiffersSignificantly(new_data);
  72     wifi_data_ = new_data;
  73     polling_policy_->UpdatePollingInterval(update_available);
  74     ScheduleNextScan(polling_policy_->PollingInterval());
  75   }
  76   if (update_available || !is_first_scan_complete_) {
  77     is_first_scan_complete_ = true;
  78     RunCallbacks();
  79   }
  80 }
  81
  82 void WifiDataProviderCommon::ScheduleNextScan(int interval) {
  83   client_loop()->PostDelayedTask(
  84       FROM_HERE,
  85       base::Bind(&WifiDataProviderCommon::DoWifiScanTask,
  86                  weak_factory_.GetWeakPtr()),
  87       base::TimeDelta::FromMilliseconds(interval));
  88 }
  89
  90 }  // namespace content