61 lines
1.9 KiB
TypeScript
61 lines
1.9 KiB
TypeScript
import consola from 'consola';
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import { connect, JetStreamClient, KV, KvOptions, NatsConnection } from 'nats';
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import { config } from '../config';
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/**
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* Singleton NATS client.
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* Call connect() once during app startup (after the DB loader).
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* All other modules obtain the connection via getKV().
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*/
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class NatsClient {
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private connection: NatsConnection | null = null;
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private js: JetStreamClient | null = null;
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private kvBuckets: Map<string, KV> = new Map();
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/**
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* Establishes the NATS connection and JetStream context.
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* Must be called once before any KV operations.
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*/
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public async connect(): Promise<void> {
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this.connection = await connect({ servers: config.nats_url });
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this.js = this.connection.jetstream();
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consola.success(`NATS connected to ${config.nats_url}`);
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}
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/**
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* Returns a KV bucket by name, creating it if it doesn't exist yet.
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* Results are cached — repeated calls with the same name return the same instance.
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*/
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public async getKV(bucketName: string, options?: Partial<KvOptions>): Promise<KV> {
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if (this.kvBuckets.has(bucketName)) {
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return this.kvBuckets.get(bucketName);
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}
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if (!this.js) {
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throw new Error('NATS not connected. Call NatsClient.connect() first.');
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}
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const kv = await this.js.views.kv(bucketName, options);
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this.kvBuckets.set(bucketName, kv);
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return kv;
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}
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/**
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* Gracefully closes the NATS connection.
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* Call during app shutdown if needed.
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*/
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public async disconnect(): Promise<void> {
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if (this.connection) {
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await this.connection.drain();
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this.connection = null;
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this.js = null;
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this.kvBuckets.clear();
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consola.info('NATS disconnected.');
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}
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}
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public isConnected(): boolean {
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return this.connection !== null;
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}
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}
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export default new NatsClient();
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