1424c4d7b64af9d0d8fd9624f381f469654d5e3d2Torne (Richard Coles)// Copyright 2013 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 5424c4d7b64af9d0d8fd9624f381f469654d5e3d2Torne (Richard Coles)#include "content/browser/geolocation/wifi_data.h" 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 74e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles)#include <algorithm> 84e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) 9424c4d7b64af9d0d8fd9624f381f469654d5e3d2Torne (Richard Coles)#include "base/logging.h" 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 11424c4d7b64af9d0d8fd9624f381f469654d5e3d2Torne (Richard Coles)namespace content { 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)AccessPointData::AccessPointData() 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : radio_signal_strength(kint32min), 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) channel(kint32min), 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) signal_to_noise(kint32min) { 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)AccessPointData::~AccessPointData() {} 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WifiData::WifiData() {} 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WifiData::~WifiData() {} 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool WifiData::DiffersSignificantly(const WifiData& other) const { 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // More than 4 or 50% of access points added or removed is significant. 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static const size_t kMinChangedAccessPoints = 4; 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const size_t min_ap_count = 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::min(access_point_data.size(), other.access_point_data.size()); 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const size_t max_ap_count = 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::max(access_point_data.size(), other.access_point_data.size()); 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const size_t difference_threadhold = std::min(kMinChangedAccessPoints, 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) min_ap_count / 2); 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (max_ap_count > min_ap_count + difference_threadhold) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return true; 36424c4d7b64af9d0d8fd9624f381f469654d5e3d2Torne (Richard Coles) // Compute size of intersection of old and new sets. 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t num_common = 0; 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (AccessPointDataSet::const_iterator iter = access_point_data.begin(); 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) iter != access_point_data.end(); 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) iter++) { 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (other.access_point_data.find(*iter) != 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) other.access_point_data.end()) { 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ++num_common; 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DCHECK(num_common <= min_ap_count); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Test how many have changed. 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return max_ap_count > num_common + difference_threadhold; 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace content 53