lrufy/dist/example.js

A feature-rich LRU cache implementation with TTL support, custom sizing, and event hooks

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const index_1 = require("./index");
/**
 * Basic usage example
 */
function basicExample() {
    const cache = new index_1.LRUCache({ max: 100 });
    cache.set("one", 1);
    cache.set("two", 2);
    cache.set("three", 3);
    console.log("Get one:", cache.get("one")); // 1
    console.log("Get missing:", cache.get("missing")); // undefined
    console.log("Has two:", cache.has("two")); // true
    cache.delete("two");
    console.log("Has two after delete:", cache.has("two")); // false
    cache.clear();
    console.log("Cache size after clear:", cache.size); // 0
}
/**
 * TTL example
 */
function ttlExample() {
    const cache = new index_1.LRUCache({
        ttl: 5000,
        allowStale: true,
    });
    cache.set("defaultTTL", { value: "expires in 5 seconds" });
    cache.set("customTTL", { value: "expires in 1 second" }, { ttl: 1000 });
    console.log("Just added - defaultTTL exists:", cache.has("defaultTTL")); // true
    console.log("Just added - customTTL exists:", cache.has("customTTL")); // true
    setTimeout(() => {
        console.log("After 2s - defaultTTL exists:", cache.has("defaultTTL")); // true
        console.log("After 2s - customTTL exists:", cache.has("customTTL")); // false (expired)
        console.log("Stale value:", cache.get("customTTL")); // { value: 'expires in 1 second' }
    }, 2000);
}
/**
 * Custom size calculation example
 */
function sizeCalculationExample() {
    const cache = new index_1.LRUCache({
        maxSize: 10 * 1024 * 1024, // 10MB
        sizeCalculation: (value) => value.length, // Size is the buffer length
    });
    const item1 = Buffer.alloc(1 * 1024 * 1024); // 1MB
    const item2 = Buffer.alloc(5 * 1024 * 1024); // 5MB
    const item3 = Buffer.alloc(6 * 1024 * 1024); // 6MB
    cache.set("item1", item1);
    cache.set("item2", item2);
    console.log("Total size before adding item3:", cache.getStats().totalSize); // ~6MB
    cache.set("item3", item3);
    console.log("Has item1 after adding item3:", cache.has("item1")); // false (evicted)
    console.log("Cache stats:", cache.getStats());
}
/**
 * Dispose callback example
 */
function disposeExample() {
    const connections = {};
    const connectionCache = new index_1.LRUCache({
        max: 5,
        dispose: (value, key, reason) => {
            console.log(`Connection ${key} was removed because: ${reason}`);
            if (connections[key]) {
                connections[key].close();
                delete connections[key];
            }
        },
    });
    for (let i = 1; i <= 7; i++) {
        const key = `conn${i}`;
        connections[key] = {
            close: () => console.log(`Connection ${key} closed`),
        };
        connectionCache.set(key, `connection-${i}`);
    }
}
/**
 * Serialization example
 */
function serializationExample() {
    const originalCache = new index_1.LRUCache();
    originalCache.set("one", 1);
    originalCache.set("two", 2);
    const serialized = originalCache.serialize();
    console.log("Serialized cache:", serialized);
    const newCache = new index_1.LRUCache();
    newCache.deserialize(serialized);
    console.log("Deserialized cache has one:", newCache.has("one")); // true
    console.log("Deserialized cache get two:", newCache.get("two")); // 2
}
console.log("===== BASIC EXAMPLE =====");
basicExample();
console.log("\n===== TTL EXAMPLE =====");
ttlExample();
console.log("\n===== SIZE CALCULATION EXAMPLE =====");
sizeCalculationExample();
console.log("\n===== DISPOSE EXAMPLE =====");
disposeExample();
console.log("\n===== SERIALIZATION EXAMPLE =====");
serializationExample();