@trifrost/core/esm/modules/RateLimit/strategies/Sliding.js

Blazingly fast, runtime-agnostic server framework for modern edge and node environments

export class Sliding {
    #window;
    #store;
    constructor(window = 60, store) {
        this.#window = window;
        this.#store = store;
    }
    get store() {
        return this.#store;
    }
    async consume(key, limit) {
        const now = Math.floor(Date.now() / 1000);
        const timestamps = (await this.#store.get(key)) || [];
        /* Prune ONLY the first entry if it's outside the window */
        if (timestamps.length && timestamps[0] < now - this.#window)
            timestamps.shift();
        /* Push the current timestamp */
        timestamps.push(now);
        /* Compute the reset time */
        const reset = timestamps[0] + this.#window;
        /* Avoid writes if we've already exceeded the limit */
        if (timestamps.length <= limit) {
            const ttl = reset - now;
            await this.#store.set(key, timestamps, { ttl: Math.max(ttl, 1) });
        }
        return { amt: timestamps.length, reset };
    }
    async stop() {
        await this.#store.stop();
    }
}