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//
// Copyright (C) 2012 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#ifndef UPDATE_ENGINE_COMMON_FAKE_PREFS_H_
#define UPDATE_ENGINE_COMMON_FAKE_PREFS_H_
#include <map>
#include <string>
#include <string_view>
#include <vector>
#include <base/macros.h>
#include "update_engine/common/prefs_interface.h"
namespace chromeos_update_engine {
// Implements a fake preference store by storing the value associated with
// a key in a std::map, suitable for testing. It doesn't allow to set a value on
// a key with a different type than the previously set type. This enforces the
// type of a given key to be fixed. Also the class checks that the Get*()
// methods aren't called on a key set with a different type.
class FakePrefs : public PrefsInterface {
public:
FakePrefs() = default;
~FakePrefs();
// PrefsInterface methods.
bool GetString(const std::string& key, std::string* value) const override;
bool SetString(const std::string& key, std::string_view value) override;
bool GetInt64(const std::string& key, int64_t* value) const override;
bool SetInt64(const std::string& key, const int64_t value) override;
bool GetBoolean(const std::string& key, bool* value) const override;
bool SetBoolean(const std::string& key, const bool value) override;
bool Exists(const std::string& key) const override;
bool Delete(const std::string& key) override;
bool Delete(const std::string& key,
const std::vector<std::string>& nss) override;
bool GetSubKeys(const std::string& ns,
std::vector<std::string>* keys) const override;
void AddObserver(const std::string& key,
ObserverInterface* observer) override;
void RemoveObserver(const std::string& key,
ObserverInterface* observer) override;
private:
enum class PrefType {
kString,
kInt64,
kBool,
};
struct PrefValue {
std::string as_str;
int64_t as_int64;
bool as_bool;
};
struct PrefTypeValue {
PrefType type;
PrefValue value;
};
// Class to store compile-time type-dependent constants.
template <typename T>
class PrefConsts {
public:
// The PrefType associated with T.
static FakePrefs::PrefType const type;
// The data member pointer to PrefValue associated with T.
static T FakePrefs::PrefValue::*const member;
};
// Returns a string representation of the PrefType useful for logging.
static std::string GetTypeName(PrefType type);
// Checks that the |key| is either not present or has the given |type|.
void CheckKeyType(const std::string& key, PrefType type) const;
// Helper function to set a value of the passed |key|. It sets the type based
// on the template parameter T.
template <typename T>
void SetValue(const std::string& key, T value);
// Helper function to get a value from the map checking for invalid calls.
// The function fails the test if you attempt to read a value defined as a
// different type. Returns whether the get succeeded.
template <typename T>
bool GetValue(const std::string& key, T* value) const;
// Container for all the key/value pairs.
std::map<std::string, PrefTypeValue> values_;
// The registered observers watching for changes.
std::map<std::string, std::vector<ObserverInterface*>> observers_;
DISALLOW_COPY_AND_ASSIGN(FakePrefs);
};
} // namespace chromeos_update_engine
#endif // UPDATE_ENGINE_COMMON_FAKE_PREFS_H_