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      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
     91