rate-keeper

rate-keeper is a lightweight utility for easily adding rate limiting to functions and preventing API rate limit violations.

Features

• Create actions with rate limits.
• Manages multiple queues by ID, allowing sequential and parallel actions.
• Helps prevent overloading of external services by managing API usage.
• Very easy to integrate into existing code.

Installation

Install the package via npm:

npm install rate-keeper

Usage

Existing code.

function logMessage(newLog) {
    console.log(newLog);
    return newLog;
}

Basic

import RateKeeper from "rate-keeper";

const safeLogger = RateKeeper(logMessage, 500); // Minimum of 500ms between calls.

safeLogger("Message 1");
safeLogger("Message 2");
safeLogger("Message 3");

Message 1
//500ms later...
Message 2
//500ms later...
Message 3

Queues

import RateKeeper from "rate-keeper";

const queueID = 1001;

const logger1 = RateKeeper(logMessage, 500, { id: queueID }); // Shared queue with logger2
const logger2 = RateKeeper(logMessage, 500, { id: queueID }); // Shared queue with logger1
const logger3 = RateKeeper(logMessage, 500); // Independent queue

logger1("Queue Message 1");
logger2("Queue Message 2");
logger3("Independent Message");

Queue Message 1
Independent Message
// 500ms later...
Queue Message 2

Queues with Options

You can configure queues with custom settings, such as a maximum queue size and policies for handling overflow. Options include Reject (discard new entries when full) or DropOldest (remove the oldest entry to make room for new ones).

import RateKeeper, { DropPolicy } from "rate-keeper";

const queueID = 2002;

const loggerWithLimit = RateKeeper(logMessage, 500, {
    id: queueID,
    maxQueueSize: 2,
    dropPolicy: DropPolicy.DropOldest, // Removes the oldest task when the queue is full
});

loggerWithLimit("Message 0"); // Processed.
loggerWithLimit("Message 1"); // Added to queue
loggerWithLimit("Message 2"); // Added to queue
loggerWithLimit("Message 3"); // "Message 1" is dropped, "Message 3" added

// Logs will be processed with a 500ms interval

Message 0
// 500ms later...
Message 2
// 500ms later...
Message 3

Promises

A function created with rate-keeper returns a promise containing the invocation result, making asynchronous handling straightforward.

import RateKeeper from "rate-keeper";

const safeLogger = RateKeeper(logMessage, 500); // Minimum of 500ms between calls.

safeLogger("Hello World 1").then((result) => {
    //...
});

Cancelable Actions

You can cancel an action that has not yet been executed.

import RateKeeper from "rate-keeper";

const safeLogger = RateKeeper(logMessage, 500); // Minimum of 500ms between calls.

safeLogger("Message 1");
const message2 = safeLogger("Message 2");
safeLogger("Message 3");

message2.cancel();

Message 1
//500ms later...
Message 3