memory-cache

library0.2.0jsnpmunverified

A simple in-memory cache for Node.js with support for TTL and expiration callbacks. Version 0.2.0 is stable with no recent releases; it uses setTimeout for expiration. Unlike more feature-rich solutions (e.g., node-cache, lru-cache), it offers a minimal API: put, get, del, clear, size, and import/export. Its constructor allows multiple isolated cache instances. Note that all operations are synchronous, and hits/misses are only tracked in debug mode.

storage

npm install memory-cache

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · MEMORY-CACHE

memory-cache

storagejavascriptv0.2.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default instance

✓ const cache = require('memory-cache');

✗ import cache from 'memory-cache';

CommonJS-only; no default ES module export. Use require().

Cache class

✓ const { Cache } = require('memory-cache');

✗ const Cache = require('memory-cache').Cache;

Both patterns work, but destructuring is idiomatic.

importJson options

✓ cache.importJson(json, { skipDuplicates: true });

✗ cache.importJson(json, true);

Second argument must be an options object, not a boolean.

Demonstrates basic put/get, TTL with callback, cache expiration, and creating a separate Cache instance.

const cache = require('memory-cache'); // store a value indefinitely cache.put('foo', 'bar'); console.log(cache.get('foo')); // 'bar' // store with TTL (100ms) and expiration callback cache.put('houdini', 'disappear', 100, function(key, value) { console.log(key + ' did ' + value); }); console.log(cache.get('houdini')); // 'disappear' setTimeout(() => { console.log(cache.get('houdini')); // null (expired) }, 200); // create a separate cache instance const myCache = new cache.Cache(); myCache.put('key', 'value'); console.log(myCache.get('key')); // 'value'

Debug

Known issues

gotchaHits and misses are only tracked when debug mode is enabled via cache.debug(true).

fix

Enable debug mode: cache.debug(true); before checking hits/misses.

affects: >=0.0.1

gotchaTTL uses setTimeout internally; accuracy may be affected by Node.js event loop delays.

fix

Do not rely on exact millisecond expiration for timing-critical use cases.

affects: >=0.0.1

gotchaimportJson with skipDuplicates: false (default) overwrites duplicate keys silently.

fix

Pass skipDuplicates: true to preserve existing keys.

affects: >=0.1.0

deprecatedNo new releases since 2017; package is in maintenance mode.

fix

Consider alternatives like node-cache or lru-cache for active development.

affects: >0.2.0

Errors

Common errors & fixes

TypeError: cache.get is not a function

Requiring the module incorrectly, e.g. const cache = require('memory-cache').Cache; returns the class, not the default instance.

fix

Use const cache = require('memory-cache'); to get the default instance.

ReferenceError: require is not defined in ES module scope

Using import statement or running in ES module mode.

fix

Switch to CommonJS or use a dynamic import: const cache = await import('memory-cache'); (note: package is not ESM).

cache.put('key', 'value', 100, function(key, value) { ... }) but callback never called

TTL value must be a number in milliseconds; if omitted or non-number, callback is ignored.

fix

Ensure the third argument is a number (time in ms).

Upgrade

Version history

0.2.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

15 hits · last 30 days

node

OpenAI (training)

Resources

githubgit://github.com/ptarjan/node-cache ↗

packagememory-cache ↗

homepagehttps://github.com/ptarjan/node-cache#readme ↗