1 /*
2 * Copyright 2014 Google Inc. All rights reserved.
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 #include "cached_greeter.h"
18 #include "key_value_storage.h"
19
20 class CachedGreeterImpl : public Greeter {
21 private:
22 Greeter* greeter;
23 KeyValueStorage* keyValueStorage;
24
25 public:
INJECT(CachedGreeterImpl (Greeter * greeter,KeyValueStorage * keyValueStorage))26 INJECT(CachedGreeterImpl(Greeter* greeter, KeyValueStorage* keyValueStorage))
27 : greeter(greeter), keyValueStorage(keyValueStorage) {
28 }
29
greet()30 std::string greet() override {
31 std::string greeting = keyValueStorage->get("greeting");
32 if (!greeting.empty()) {
33 return greeting;
34 }
35
36 // Not in the cache, we need to compute the greeting.
37 greeting = greeter->greet();
38
39 // We also add it in the cache so that later calls don't need to call greeter->greet().
40 keyValueStorage->put("greeting", greeting);
41
42 return greeting;
43 }
44 };
45
getCachedGreeterComponent()46 fruit::Component<fruit::Annotated<Cached, Greeter>> getCachedGreeterComponent() {
47 return fruit::createComponent()
48 .bind<fruit::Annotated<Cached, Greeter>, CachedGreeterImpl>()
49 .install(getKeyValueStorageComponent)
50 .install(getGreeterComponent);
51 }
52