index.d.ts

// Type definitions for node-cache 5
// Project: https://github.com/tcs-de/nodecache
// Definitions by: Ilya Mochalov <https://github.com/chrootsu>
//                 Daniel Thunell <https://github.com/dthunell>
//                 Ulf Seltmann <https://github.com/useltmann>
// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped

/// <reference types="node" />

declare namespace NodeCache {
	interface NodeCacheLegacyCallbacks {
		/** container for cached data */
		data: Data;

		/** module options */
		options: Options;

		/** statistics container */
		stats: Stats;

		/**
		 * get a cached key and change the stats
		 *
		 * @param key cache key or an array of keys
		 * @param cb Callback function
		 */
		get<T>(
			key: Key,
			cb?: Callback<T>
		): T | undefined;

		/**
		 * get multiple cached keys at once and change the stats
		 *
		 * @param keys an array of keys
		 * @param cb Callback function
		 */
		mget<T>(
			keys: Key[],
			cb?: Callback<{ [key: string]: T }>
		): { [key: string]: T };

		/**
		 * set a cached key and change the stats
		 *
		 * @param key cache key
		 * @param value A element to cache. If the option `option.forceString` is `true` the module trys to translate
		 * it to a serialized JSON
		 * @param ttl The time to live in seconds.
		 * @param cb Callback function
		 */
		set<T>(
			key: Key,
			value: T,
			ttl: number | string,
			cb?: Callback<boolean>
		): boolean;

		set<T>(
			key: Key,
			value: T,
			cb?: Callback<boolean>
		): boolean;

		/**
		 * set multiple cached keys at once and change the stats
		 *
		 * @param keyValueSet  an array of object which includes key,value and ttl
		 */
		mset<T>(
			keyValueSet: ValueSetItem<T>[],
		): boolean;

		/**
		 * remove keys
		 * @param keys cache key to delete or a array of cache keys
		 * @param cb Callback function
		 * @returns Number of deleted keys
		 */
		del(
			keys: Key | Key[],
			cb?: Callback<number>
		): number;

		/**
		 * reset or redefine the ttl of a key. If `ttl` is not passed or set to 0 it's similar to `.del()`
		 */
		ttl(
			key: Key,
			ttl: number,
			cb?: Callback<boolean>
		): boolean;

		ttl(
			key: Key,
			cb?: Callback<boolean>
		): boolean;

		getTtl(
			key: Key,
		): number|undefined;

		getTtl(
			key: Key,
			cb?: Callback<boolean>
		): boolean;

		/**
		 * list all keys within this cache
		 * @param cb Callback function
		 * @returns An array of all keys
		 */
		keys(cb?: Callback<string[]>): string[];

		/**
		 * get the stats
		 *
		 * @returns Stats data
		 */
		getStats(): Stats;

		/**
		 * flush the whole data and reset the stats
		 */
		flushAll(): void;

		/**
		 * This will clear the interval timeout which is set on checkperiod option.
		 */
		close(): void;
	}

	/**
	 * Since 4.1.0: Key-validation: The keys can be given as either string or number,
	 * but are casted to a string internally anyway.
	 */
	type Key = string | number;

	type ValueSetItem<T = any> = {
		key: Key;
		val: T;
		ttl?: number;
	}

	interface Data {
		[key: string]: WrappedValue<any>;
	}

	interface Options {
		/**
		 * If enabled, all values will be stringified during the set operation
		 *
		 * @type {boolean}
		 * @memberof Options
		 */
		forceString?: boolean;

		objectValueSize?: number;
		promiseValueSize?: number;
		arrayValueSize?: number;

		/**
		 * standard time to live in seconds. 0 = infinity
		 *
		 * @type {number}
		 * @memberof Options
		 */
		stdTTL?: number;

		/**
		 * time in seconds to check all data and delete expired keys
		 *
		 * @type {number}
		 * @memberof Options
		 */
		checkperiod?: number;

		/**
		 * en/disable cloning of variables.
		 * disabling this is strongly encouraged when aiming for performance!
		 *
		 * If `true`: set operations store a clone of the value and get operations will create a fresh clone of the cached value
		 * If `false` you'll just store a reference to your value
		 *
		 * @type {boolean}
		 * @memberof Options
		 */
		useClones?: boolean;

		errorOnMissing?: boolean;
		deleteOnExpire?: boolean;

		/**
		 * enable legacy callbacks.
		 * legacy callback support will drop in v6.x!
		 *
		 * @type {boolean}
		 * @memberof Options
		 */
		enableLegacyCallbacks?: boolean;

		/**
		 * max amount of keys that are being stored.
		 * set operations will throw an error when the cache is full
		 *
		 * @type {number}
		 * @memberof Options
		 */
		maxKeys?: number;
	}

	interface Stats {
		hits: number;
		misses: number;
		keys: number;
		ksize: number;
		vsize: number;
	}

	interface WrappedValue<T> {
		// ttl
		t: number;
		// value
		v: T;
	}

	type Callback<T> = (err: any, data: T | undefined) => void;
}

import events = require("events");

import Data = NodeCache.Data;
import Key = NodeCache.Key;
import Options = NodeCache.Options;
import Stats = NodeCache.Stats;
import Callback = NodeCache.Callback;
import ValueSetItem = NodeCache.ValueSetItem;
import NodeCacheLegacyCallbacks = NodeCache.NodeCacheLegacyCallbacks;

declare class NodeCache extends events.EventEmitter {
	/** container for cached data */
	data: Data;

	/** module options */
	options: Options;

	/** statistics container */
	stats: Stats;

	/** constructor */
	constructor(options?: Options);

	/**
	 * get a cached key and change the stats
	 *
	 * @param key cache key
	 * @returns The value stored in the key
	 */
	get<T>(
		key: Key
	): T | undefined;

	/**
	 * get multiple cached keys at once and change the stats
	 *
	 * @param keys an array of keys
	 * @returns an object containing the values stored in the matching keys
	 */
	mget<T>(
		keys: Key[]
	): { [key: string]: T };

	/**
	 * set a cached key and change the stats
	 *
	 * @param key cache key
	 * @param value A element to cache. If the option `option.forceString` is `true` the module trys to translate
	 * it to a serialized JSON
	 * @param ttl The time to live in seconds.
	 */
	set<T>(
		key: Key,
		value: T,
		ttl: number | string
	): boolean;

	set<T>(
		key: Key,
		value: T
	): boolean;

	/**
	 * in the event of a cache miss (no value is assinged to given cache key), value will be written to cache and returned. In case of cache hit, cached value will be returned without executing given value. If the given value is type of `Function`, it will be executed and returned result will be fetched
	 * 
	 * @param key cache key
	 * @param ttl The time to live in seconds.
	 * @param value function that returns a value to be stored in cache, or the value itself
	 */
	fetch<T>(
		key: Key,
		ttl: number | string,
		value: () => T,
  ): T;

	fetch<T>(
		key: Key,
		value: () => T,
	): T;

	/**
	 * set multiple cached keys at once and change the stats
	 *
	 * @param keyValueSet an array of object which includes key,value and ttl
	 */
	mset<T>(
		keyValueSet: ValueSetItem<T>[]
	): boolean;

	/**
	 * remove keys
	 * @param keys cache key to delete or a array of cache keys
	 * @param cb Callback function
	 * @returns Number of deleted keys
	 */
	del(
		keys: Key | Key[]
	): number;

	/**
	 * get a cached key and remove it from the cache.
	 * Equivalent to calling `get(key)` + `del(key)`.
	 * Useful for implementing `single use` mechanism such as OTP, where once a value is read it will become obsolete.
	 *
	 * @param key cache key
	 * @returns The value stored in the key
	 */
	take<T>(
		key: Key
	): T | undefined;
					  
	/**
	 * reset or redefine the ttl of a key. If `ttl` is not passed or set to 0 it's similar to `.del()`
	 */
	ttl(
		key: Key,
		ttl: number
	): boolean;

	ttl(
		key: Key
	): boolean;

	getTtl(
		key: Key,
	): number|undefined;

	getTtl(
		key: Key
	): boolean;

	/**
	 * list all keys within this cache
	 * @returns An array of all keys
	 */
	keys(): string[];

	/**
	 * get the stats
	 *
	 * @returns Stats data
	 */
	getStats(): Stats;

	/**
	 * Check if a key is cached
	 * @param key cache key to check
	 * @returns Boolean indicating if the key is cached or not
	 */
	has(key: Key): boolean;

	/**
	 * flush the whole data and reset the stats
	 */
	flushAll(): void;

	/**
	 * This will clear the interval timeout which is set on checkperiod option.
	 */
	close(): void;

	/**
	 * flush the stats and reset all counters to 0
	 */
	flushStats(): void;
}


export = NodeCache;