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 UPDATE_ENGINE_COMMON_FAKE_PREFS_H_ 18 #define UPDATE_ENGINE_COMMON_FAKE_PREFS_H_ 19 20 #include <map> 21 #include <string> 22 #include <vector> 23 24 #include <base/macros.h> 25 26 #include "update_engine/common/prefs_interface.h" 27 28 namespace chromeos_update_engine { 29 30 // Implements a fake preference store by storing the value associated with 31 // a key in a std::map, suitable for testing. It doesn't allow to set a value on 32 // a key with a different type than the previously set type. This enforces the 33 // type of a given key to be fixed. Also the class checks that the Get*() 34 // methods aren't called on a key set with a different type. 35 36 class FakePrefs : public PrefsInterface { 37 public: 38 FakePrefs() = default; 39 ~FakePrefs(); 40 41 // PrefsInterface methods. 42 bool GetString(const std::string& key, std::string* value) const override; 43 bool SetString(const std::string& key, const std::string& value) override; 44 bool GetInt64(const std::string& key, int64_t* value) const override; 45 bool SetInt64(const std::string& key, const int64_t value) override; 46 bool GetBoolean(const std::string& key, bool* value) const override; 47 bool SetBoolean(const std::string& key, const bool value) override; 48 49 bool Exists(const std::string& key) const override; 50 bool Delete(const std::string& key) override; 51 52 void AddObserver(const std::string& key, 53 ObserverInterface* observer) override; 54 void RemoveObserver(const std::string& key, 55 ObserverInterface* observer) override; 56 57 private: 58 enum class PrefType { 59 kString, 60 kInt64, 61 kBool, 62 }; 63 struct PrefValue { 64 std::string as_str; 65 int64_t as_int64; 66 bool as_bool; 67 }; 68 69 struct PrefTypeValue { 70 PrefType type; 71 PrefValue value; 72 }; 73 74 // Class to store compile-time type-dependent constants. 75 template <typename T> 76 class PrefConsts { 77 public: 78 // The PrefType associated with T. 79 static FakePrefs::PrefType const type; 80 81 // The data member pointer to PrefValue associated with T. 82 static T FakePrefs::PrefValue::*const member; 83 }; 84 85 // Returns a string representation of the PrefType useful for logging. 86 static std::string GetTypeName(PrefType type); 87 88 // Checks that the |key| is either not present or has the given |type|. 89 void CheckKeyType(const std::string& key, PrefType type) const; 90 91 // Helper function to set a value of the passed |key|. It sets the type based 92 // on the template parameter T. 93 template <typename T> 94 void SetValue(const std::string& key, const T& value); 95 96 // Helper function to get a value from the map checking for invalid calls. 97 // The function fails the test if you attempt to read a value defined as a 98 // different type. Returns whether the get succeeded. 99 template <typename T> 100 bool GetValue(const std::string& key, T* value) const; 101 102 // Container for all the key/value pairs. 103 std::map<std::string, PrefTypeValue> values_; 104 105 // The registered observers watching for changes. 106 std::map<std::string, std::vector<ObserverInterface*>> observers_; 107 108 DISALLOW_COPY_AND_ASSIGN(FakePrefs); 109 }; 110 111 } // namespace chromeos_update_engine 112 113 #endif // UPDATE_ENGINE_COMMON_FAKE_PREFS_H_ 114