feat(Redis-Memory Storage): Caching module with redis and memory storage and supporting decorators

Author: Gokul Chandran

index.d.ts

@@ -0,0 +1,2 @@
+export { Cache, CacheClear, RedisStorage, ExpirationStrategy, MemoryStorage, 
+  LbServicesCacheComponent, CacheBindings, CacheRequest, CacheStrategyResolverProvider} from './lib/cache/src';

index.js

@@ -1,6 +1 @@
-module.exports= 
-{
-  Cache : require('./lib/cache'),
-  Middleware: require('./lib/middleware'),
-  Class: require('./lib/class')
-}
+module.exports = require('./dist');

index.ts

@@ -0,0 +1 @@
+export * from './src';

lib/cache/LICENSE

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+MIT License
+
+Copyright (c) 2017 Himmet Avsar
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

lib/cache/README.md

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+[![Travis CI](https://img.shields.io/travis/havsar/node-ts-cache.svg)](https://travis-ci.org/havsar/node-ts-cache) 
+[![David](https://img.shields.io/david/havsar/node-ts-cache.svg)](https://david-dm.org/havsar/node-ts-cache)
+[![npm](https://img.shields.io/npm/v/node-ts-cache.svg)](https://www.npmjs.org/package/node-ts-cache)
+[![The MIT License](https://img.shields.io/npm/l/node-ts-cache.svg)](http://opensource.org/licenses/MIT)
+
+[![NPM](https://nodei.co/npm/node-ts-cache.png?downloads=true&downloadRank=true&stars=true)](https://nodei.co/npm/node-ts-cache/)
+
+# labshare/services-cache 
+Simple and extensible caching module with redis and memory storage and supporting decorators.
+
+<!-- TOC depthTo:2 -->
+
+- [node-ts-cache](#labshare/services-cache )
+- [Install](#install)
+- [Usage](#usage)
+    - [With decorator](#with-decorator)
+    - [Directly](#directly)
+- [Strategies](#strategies)
+    - [ExpirationStrategy](#expirationstrategy)
+- [Storages](#storages)
+- [Test](#test)
+
+<!-- /TOC -->
+
+# Install
+```bash
+npm install --save @labshare/services-cache 
+```
+
+# Usage
+## With decorator
+Caches function response using the given options. Works with different strategies and storages. Uses all arguments to build an unique key.
+
+`@Cache(options)`
+- `options`: Options passed to the strategy for this particular method
+
+*Note: @Cache always converts the method response to a promise because caching might be async.* 
+
+```ts
+import { Cache, ExpirationStrategy, MemoryStorage } from "@labshare/services-cache";
+
+class MyService {
+    
+    @Cache(myStrategy, { ttl: 60 })
+    public async getUsers(): Promise<string[]> {
+        return ["John", "Doe"];
+    }
+}
+```
+
+## Directly
+
+```ts
+import { ExpirationStrategy, MemoryStorage } from "@labshare/services-cache";
+
+const memoryCache = new ExpirationStrategy(new MemoryStorage());
+
+class MyService {
+    
+    public async getUsers(): Promise<string[]> {
+        const cachedUsers = await memoryCache.getItem<string[]>("users");
+        if (cachedUsers) {
+            return cachedUsers;
+        }
+
+        const newUsers = ["John", "Doe"];
+        await memoryCache.setItem("users", newUsers, {  ttl: 60 });
+
+        return newUsers;
+    }
+}
+```
+
+# Strategies
+## ExpirationStrategy
+Cached items expire after a given amount of time.
+
+ - `ttl`: *(Default: 60)* Number of seconds to expire the cachte item
+ - `isLazy`: *(Default: true)* If true, expired cache entries will be deleted on touch. If false, entries will be deleted after the given *ttl*.
+ - `isCachedForver`: *(Default: false)* If true, cache entry has no expiration.
+ - `refreshCache,`: boolean.
+ - `noop?`: boolean; // Allows for consuming libraries to conditionally disable caching. Set this to true to disable caching for some reason.
+
+
+# Storages
+
+*Note: For specific storages, client libraries must be installed:*
+
+| Storage      | Needed client library |
+|--------------|:---------------------:|
+| RedisStorage |  `npm install redis`  |
+
+#### MemoryStorage()
+#### FsJsonStorage(`fileName: string`)
+#### RedisStorage(`clientOpts:` [RedisClientOptions](https://github.com/NodeRedis/node_redis#options-object-properties))
+
+
+# Test
+```bash
+npm test
+```

lib/cache/index.d.ts

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+// export { Cache, CacheClear, RedisStorage, ExpirationStrategy, MemoryStorage, 
+//     LbServicesCacheComponent, CacheBindings, CacheRequest, CacheStrategyResolverProvider} from './src';