1 // Copyright (C) 2014 Google Inc. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef I18N_ADDRESSINPUT_ONDEMAND_SUPPLIER_H_ 16 #define I18N_ADDRESSINPUT_ONDEMAND_SUPPLIER_H_ 17 18 #include <libaddressinput/callback.h> 19 #include <libaddressinput/supplier.h> 20 #include <libaddressinput/util/basictypes.h> 21 #include <libaddressinput/util/scoped_ptr.h> 22 23 #include <map> 24 #include <string> 25 26 namespace i18n { 27 namespace addressinput { 28 29 class Downloader; 30 class LookupKey; 31 class Retriever; 32 class Rule; 33 class Storage; 34 35 // An implementation of the Supplier interface that owns a Retriever object, 36 // through which it loads address metadata as needed, creating Rule objects and 37 // caching these. 38 // 39 // When using an OndemandSupplier, address validation will benefit from address 40 // metadata server synonym resolution, because the server will be contacted for 41 // every new LookupKey (ie. every LookupKey that isn't on canonical form and 42 // isn't already cached). 43 // 44 // The maximum size of this cache is naturally limited to the amount of data 45 // available from the data server. (Currently this is less than 12,000 items of 46 // in total less than 2 MB of JSON data.) 47 class OndemandSupplier : public Supplier { 48 public: 49 // Takes ownership of |downloader| and |storage|. The |validation_data_url| 50 // should be a URL to an address data server that |downloader| can access. 51 // 52 // (See the documentation for the Downloader implementation used for 53 // information about what URLs are useable with that Downloader.) 54 OndemandSupplier(const std::string& validation_data_url, 55 const Downloader* downloader, 56 Storage* storage); 57 virtual ~OndemandSupplier(); 58 59 // Loads the metadata needed for |lookup_key|, then calls |supplied|. 60 virtual void Supply(const LookupKey& lookup_key, const Callback& supplied); 61 62 private: 63 const scoped_ptr<const Retriever> retriever_; 64 std::map<std::string, const Rule*> rule_cache_; 65 66 DISALLOW_COPY_AND_ASSIGN(OndemandSupplier); 67 }; 68 69 } // namespace addressinput 70 } // namespace i18n 71 72 #endif // I18N_ADDRESSINPUT_ONDEMAND_SUPPLIER_H_ 73
