kafka-ts/dist/utils/promise-chain.js

**KafkaTS** is a Apache Kafka client library for Node.js. It provides both a low-level API for communicating directly with the Apache Kafka cluster and high-level APIs for publishing and subscribing to Kafka topics.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.PromiseChain = void 0;
class PromiseChain {
    locks = new Map();
    async run(keys, callback) {
        const orderedKeys = [...new Set(keys)].sort();
        const releases = [];
        for (const key of orderedKeys) {
            const release = await this.acquire(key);
            releases.push(release);
        }
        try {
            await callback();
        }
        finally {
            releases.reverse().forEach((release) => release());
        }
    }
    async acquire(key) {
        const previousTail = this.locks.get(key);
        let release;
        const currentTail = new Promise((resolve) => (release = resolve));
        if (previousTail) {
            this.locks.set(key, previousTail.then(() => currentTail));
            await previousTail;
        }
        else {
            this.locks.set(key, currentTail);
        }
        return () => {
            release();
            if (this.locks.get(key) === currentTail) {
                this.locks.delete(key);
            }
        };
    }
}
exports.PromiseChain = PromiseChain;