1//
2// Copyright (C) 2014 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_UPDATE_MANAGER_FAKE_VARIABLE_H_
18#define UPDATE_ENGINE_UPDATE_MANAGER_FAKE_VARIABLE_H_
19
20#include <memory>
21#include <string>
22
23#include "update_engine/update_manager/variable.h"
24
25namespace chromeos_update_manager {
26
27// A fake typed variable to use while testing policy implementations. The
28// variable can be instructed to return any object of its type.
29template<typename T>
30class FakeVariable : public Variable<T> {
31 public:
32  FakeVariable(const std::string& name, VariableMode mode)
33      : Variable<T>(name, mode) {}
34  FakeVariable(const std::string& name, base::TimeDelta poll_interval)
35      : Variable<T>(name, poll_interval) {}
36  ~FakeVariable() override {}
37
38  // Sets the next value of this variable to the passed |p_value| pointer. Once
39  // returned by GetValue(), the pointer is released and has to be set again.
40  // A value of null means that the GetValue() call will fail and return
41  // null.
42  void reset(const T* p_value) {
43    ptr_.reset(p_value);
44  }
45
46  // Make the NotifyValueChanged() public for FakeVariables.
47  void NotifyValueChanged() {
48    Variable<T>::NotifyValueChanged();
49  }
50
51 protected:
52  // Variable<T> overrides.
53  // Returns the pointer set with reset(). The ownership of the object is passed
54  // to the caller and the pointer is release from the FakeVariable. A second
55  // call to GetValue() without reset() will return null and set the error
56  // message.
57  const T* GetValue(base::TimeDelta /* timeout */,
58                    std::string* errmsg) override {
59    if (ptr_ == nullptr && errmsg != nullptr)
60      *errmsg = this->GetName() + " is an empty FakeVariable";
61    // Passes the pointer ownership to the caller.
62    return ptr_.release();
63  }
64
65 private:
66  // The pointer returned by GetValue().
67  std::unique_ptr<const T> ptr_;
68
69  DISALLOW_COPY_AND_ASSIGN(FakeVariable);
70};
71
72}  // namespace chromeos_update_manager
73
74#endif  // UPDATE_ENGINE_UPDATE_MANAGER_FAKE_VARIABLE_H_
75