p-ratelimit/build/src/rateLimit.js

Promise-based utility to make sure you don’t call rate-limited APIs too quickly.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.pRateLimit = void 0;
const dequeue_1 = require("./dequeue");
const quotaManager_1 = require("./quota/quotaManager");
const rateLimitTimeoutError_1 = require("./rateLimitTimeoutError");
function pRateLimit(quotaManager) {
    if (!(quotaManager instanceof quotaManager_1.QuotaManager)) {
        return pRateLimit(new quotaManager_1.QuotaManager(quotaManager));
    }
    const queue = new dequeue_1.Dequeue();
    let timerId = null;
    const next = () => {
        while (queue.length && quotaManager.start()) {
            queue.shift()();
        }
        if (queue.length && !quotaManager.activeCount && !timerId) {
            timerId = setTimeout(() => {
                timerId = null;
                next();
            }, 100);
        }
    };
    return (fn) => {
        return new Promise((resolve, reject) => {
            let timerId = null;
            if (quotaManager.maxDelay) {
                timerId = setTimeout(() => {
                    timerId = null;
                    reject(new rateLimitTimeoutError_1.RateLimitTimeoutError('queue maxDelay timeout exceeded'));
                    next();
                }, quotaManager.maxDelay);
            }
            const run = () => {
                if (quotaManager.maxDelay) {
                    if (timerId) {
                        clearTimeout(timerId);
                    }
                    else {
                        // timeout already fired
                        return;
                    }
                }
                fn()
                    .then(val => {
                    quotaManager.end();
                    resolve(val);
                })
                    .catch(err => {
                    quotaManager.end();
                    reject(err);
                })
                    .then(() => {
                    next();
                });
            };
            queue.push(run);
            next();
        });
    };
}
exports.pRateLimit = pRateLimit;
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