node-redlock
Version:
A distributed locking algorithm used to manage distributed resources in a system.
99 lines (87 loc) • 4.87 kB
HTML
<html>
<head>
<meta charset="UTF-8">
<title>example.ts</title>
<script type="module" src="https://cdn.jsdelivr.net/npm/mermaid@10/dist/mermaid.esm.min.mjs"></script>
<style>body { font-family: sans-serif; padding: 2rem; max-width: 800px; margin: auto; }</style>
</head>
<body>
<h1>example.ts</h1>
<h2> Introduction and Overview</h2>
<p>This TypeScript/JavaScript code is a simple example of how to use the <code>ioredis</code> and <code>redlock</code> libraries for managing distributed locks in a Node.js application. The code demonstrates how to create clients for Redis, a popular key-value store, using both the <code>ioredis</code> library and the <code>redis-sentinel</code> package. It then shows how to use these clients with the <code>redlock</code> library to acquire and release locks on a resource.</p>
<h2>System Architecture</h2>
<p>The architecture of this system is based on the client-server model, where the Redis server acts as the central data store and the Node.js application acts as the client that interacts with the Redis server. The <code>redlock</code> library is used to manage distributed locks across multiple Redis clients, ensuring that only one client can acquire a lock at a time.</p>
<h2>Data Design</h2>
<p>The code uses Redis as the data store, which stores key-value pairs. In this example, the key is a string representing a resource, and the value is a boolean indicating whether the lock is currently held.</p>
<h2>Interface Design</h2>
<p>There are no user interfaces in this code, as it is focused on the internal workings of the application rather than its interaction with users.</p>
<h2>Component Design</h2>
<p>The main components in this code are:</p>
<ul>
<li><code>Redis</code>: a class that represents a Redis client created using the <code>ioredis</code> library.</li>
<li><code>IoredisClient</code>: an interface that defines the methods for interacting with a Redis client.</li>
<li><code>RedisJsClient</code>: a class that implements the <code>IoredisClient</code> interface and provides additional functionality for managing distributed locks using <code>redlock</code>.</li>
<li><code>Redlock</code>: a class that manages distributed locks across multiple Redis clients.</li>
</ul>
<h2>User Interface Design</h2>
<p>There is no user interface in this code, as it is focused on the internal workings of the application rather than its interaction with users.</p>
<h2>Assumptions and Dependencies</h2>
<ul>
<li>The <code>ioredis</code> and <code>redis-sentinel</code> libraries are installed and properly configured.</li>
<li>The Redis server is running and accessible from the Node.js application.</li>
<li>The <code>redlock</code> library is installed and properly configured.</li>
</ul>
<h2>Glossary of Terms</h2>
<ul>
<li>Redis: a popular key-value store that is used as the data store in this example.</li>
<li>Distributed lock: a mechanism for ensuring that only one client can access a resource at a time, even when multiple clients are running concurrently.</li>
<li>Redis client: an object that represents a connection to a Redis server and provides methods for interacting with the server.</li>
<li><code>IoredisClient</code>: an interface that defines the methods for interacting with a Redis client.</li>
<li><code>RedisJsClient</code>: a class that implements the <code>IoredisClient</code> interface and provides additional functionality for managing distributed locks using <code>redlock</code>.</li>
<li><code>Redlock</code>: a class that manages distributed locks across multiple Redis clients.</li>
</ul>
<h2>Class Diagram (in Mermaid syntax)</h2>
<pre><code class="language-mermaid">class Redis {
host: string;
port: number;
constructor(options: object) {
this.host = options.host;
this.port = options.port;
}
}
interface IRedisClient {
get(key: string): Promise<string | null>;
set(key: string, value: boolean): Promise<void>;
quit(): Promise<void>;
}
class RedisJsClient implements IRedisClient {
url: string;
constructor(options: object) {
this.url = options.url;
}
async get(key: string): Promise<string | null> {
// Implementation of the get method
}
async set(key: string, value: boolean): Promise<void> {
// Implementation of the set method
}
async quit(): Promise<void> {
// Implementation of the quit method
}
}
class Redlock {
clients: IRedisClient[];
constructor(clients: IRedisClient[]) {
this.clients = clients;
}
async acquireLock(resource: string, ttl: number): Promise<boolean | null> {
// Implementation of the acquireLock method
}
async releaseLock(resource: string, lockValue: boolean | null): Promise<void> {
// Implementation of the releaseLock method
}
}
</code></pre>
</body>
</html>