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 #ifndef CONTENT_BROWSER_GEOLOCATION_NETWORK_LOCATION_PROVIDER_H_ 6 #define CONTENT_BROWSER_GEOLOCATION_NETWORK_LOCATION_PROVIDER_H_ 7 8 #include <list> 9 #include <map> 10 11 #include "base/basictypes.h" 12 #include "base/memory/ref_counted.h" 13 #include "base/memory/scoped_ptr.h" 14 #include "base/memory/weak_ptr.h" 15 #include "base/strings/string16.h" 16 #include "base/threading/non_thread_safe.h" 17 #include "base/threading/thread.h" 18 #include "content/browser/geolocation/location_provider_base.h" 19 #include "content/browser/geolocation/network_location_request.h" 20 #include "content/browser/geolocation/wifi_data_provider.h" 21 #include "content/common/content_export.h" 22 #include "content/public/common/geoposition.h" 23 24 namespace content { 25 class AccessTokenStore; 26 27 28 class NetworkLocationProvider 29 : public base::NonThreadSafe, 30 public LocationProviderBase { 31 public: 32 // Cache of recently resolved locations. Public for tests. 33 class CONTENT_EXPORT PositionCache { 34 public: 35 // The maximum size of the cache of positions. 36 static const size_t kMaximumSize; 37 38 PositionCache(); 39 ~PositionCache(); 40 41 // Caches the current position response for the current set of cell ID and 42 // WiFi data. In the case of the cache exceeding kMaximumSize this will 43 // evict old entries in FIFO orderer of being added. 44 // Returns true on success, false otherwise. 45 bool CachePosition(const WifiData& wifi_data, 46 const Geoposition& position); 47 48 // Searches for a cached position response for the current set of data. 49 // Returns NULL if the position is not in the cache, or the cached 50 // position if available. Ownership remains with the cache. 51 const Geoposition* FindPosition(const WifiData& wifi_data); 52 53 private: 54 // Makes the key for the map of cached positions, using a set of 55 // data. Returns true if a good key was generated, false otherwise. 56 static bool MakeKey(const WifiData& wifi_data, 57 base::string16* key); 58 59 // The cache of positions. This is stored as a map keyed on a string that 60 // represents a set of data, and a list to provide 61 // least-recently-added eviction. 62 typedef std::map<base::string16, Geoposition> CacheMap; 63 CacheMap cache_; 64 typedef std::list<CacheMap::iterator> CacheAgeList; 65 CacheAgeList cache_age_list_; // Oldest first. 66 }; 67 68 NetworkLocationProvider(AccessTokenStore* access_token_store, 69 net::URLRequestContextGetter* context, 70 const GURL& url, 71 const base::string16& access_token); 72 virtual ~NetworkLocationProvider(); 73 74 // LocationProvider implementation 75 virtual bool StartProvider(bool high_accuracy) OVERRIDE; 76 virtual void StopProvider() OVERRIDE; 77 virtual void GetPosition(Geoposition *position) OVERRIDE; 78 virtual void RequestRefresh() OVERRIDE; 79 virtual void OnPermissionGranted() OVERRIDE; 80 81 private: 82 // Satisfies a position request from cache or network. 83 void RequestPosition(); 84 85 // Called from a callback when new wifi data is available. 86 void WifiDataUpdateAvailable(WifiDataProvider* provider); 87 88 // Internal helper used by WifiDataUpdateAvailable. 89 void OnWifiDataUpdated(); 90 91 bool IsStarted() const; 92 93 void LocationResponseAvailable(const Geoposition& position, 94 bool server_error, 95 const base::string16& access_token, 96 const WifiData& wifi_data); 97 98 scoped_refptr<AccessTokenStore> access_token_store_; 99 100 // The wifi data provider, acquired via global factories. 101 WifiDataProvider* wifi_data_provider_; 102 103 WifiDataProvider::WifiDataUpdateCallback wifi_data_update_callback_; 104 105 // The wifi data and a flag to indicate if the data set is complete. 106 WifiData wifi_data_; 107 bool is_wifi_data_complete_; 108 109 // The timestamp for the latest wifi data update. 110 base::Time wifi_data_updated_timestamp_; 111 112 // Cached value loaded from the token store or set by a previous server 113 // response, and sent in each subsequent network request. 114 base::string16 access_token_; 115 116 // The current best position estimate. 117 Geoposition position_; 118 119 // Whether permission has been granted for the provider to operate. 120 bool is_permission_granted_; 121 122 bool is_new_data_available_; 123 124 // The network location request object, and the url it uses. 125 scoped_ptr<NetworkLocationRequest> request_; 126 127 // The cache of positions. 128 scoped_ptr<PositionCache> position_cache_; 129 130 base::WeakPtrFactory<NetworkLocationProvider> weak_factory_; 131 132 DISALLOW_COPY_AND_ASSIGN(NetworkLocationProvider); 133 }; 134 135 // Factory functions for the various types of location provider to abstract 136 // over the platform-dependent implementations. 137 CONTENT_EXPORT LocationProviderBase* NewNetworkLocationProvider( 138 AccessTokenStore* access_token_store, 139 net::URLRequestContextGetter* context, 140 const GURL& url, 141 const base::string16& access_token); 142 143 } // namespace content 144 145 #endif // CONTENT_BROWSER_GEOLOCATION_NETWORK_LOCATION_PROVIDER_H_ 146