observation-js/dist/core/cache.js

A fully-typed TypeScript client for the waarneming.nl API.

export class InMemoryCache {
    #cache = new Map();
    get(key) {
        const entry = this.#cache.get(key);
        if (!entry)
            return undefined;
        if (entry.expires > Date.now()) {
            return entry.data;
        }
        // Clean up expired entry
        this.#cache.delete(key);
        return undefined;
    }
    set(key, value, ttl) {
        this.#cache.set(key, {
            data: value,
            expires: Date.now() + ttl * 1000,
        });
    }
    delete(key) {
        this.#cache.delete(key);
    }
    has(key) {
        // We check `get` to make sure we don't say we "have" an expired key
        return this.get(key) !== undefined;
    }
}