1 // 2 // Copyright (C) 2012 The Android Open Source Project 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // http://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 // 16 17 #ifndef SHILL_PROPERTY_ITERATOR_H_ 18 #define SHILL_PROPERTY_ITERATOR_H_ 19 20 #include <map> 21 #include <string> 22 23 #include "shill/accessor_interface.h" 24 #include "shill/error.h" 25 26 namespace shill { 27 28 // An iterator wrapper class to hide the details of what kind of data structure 29 // we're using to store key/value pairs for properties. It is intended for use 30 // with PropertyStore and always advances to the next readable property. 31 template <class V> 32 class ReadablePropertyConstIterator { 33 public: 34 ~ReadablePropertyConstIterator() {} 35 36 bool AtEnd() const { return it_ == collection_.end(); } 37 38 void Advance() { 39 if (!AtEnd()) { 40 do { 41 ++it_; 42 } while (MustAdvance()); 43 } 44 } 45 46 const std::string& Key() const { return it_->first; } 47 48 const V& value() const { return value_; } 49 50 private: 51 friend class PropertyStore; 52 53 typedef std::shared_ptr<AccessorInterface<V>> VAccessorPtr; 54 55 explicit ReadablePropertyConstIterator( 56 const typename std::map<std::string, VAccessorPtr>& collection) 57 : collection_(collection), 58 it_(collection_.begin()), 59 value_() { 60 if (MustAdvance()) { 61 Advance(); 62 } 63 } 64 65 bool MustAdvance() { return !AtEnd() && !RetrieveCurrentValue(); } 66 67 bool RetrieveCurrentValue() { 68 Error error; 69 value_ = it_->second->Get(&error); 70 return error.IsSuccess(); 71 } 72 73 const typename std::map<std::string, VAccessorPtr>& collection_; 74 typename std::map<std::string, VAccessorPtr>::const_iterator it_; 75 V value_; 76 }; 77 78 } // namespace shill 79 80 #endif // SHILL_PROPERTY_ITERATOR_H_ 81
