dw-cache

library0.0.120jsnpmunverified

Dual Window Cache (DWC) is a high-performance constant-time cache algorithm in TypeScript/JavaScript, implemented in the dw-cache npm package at version 0.0.120. It claims the highest engineering hit ratio among general-purpose caching algorithms by using only two lists for low overhead and latency, with resistance to scan, loop, and burst access patterns. Unlike LIRS or TinyLFU, DWC avoids batch processing, linear-time operations, and excessive memory overhead. It ships with TypeScript types and is actively maintained. Recommended for cache sizes above 200 entries (ideally 5,000+) for optimal statistical precision. The package is a standalone implementation of the DWC algorithm, now maintained as part of the spica monorepo.

storage testing

npm install dw-cache

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · DW-CACHE

dw-cache

storagejavascriptv0.0.120

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.

Cache

✓ import { Cache } from 'dw-cache'

✗ import Cache from 'dw-cache'

Named export since the package ships TypeScript types. Default import will fail.

Cache (CommonJS)

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

✗ const Cache = require('dw-cache')

CommonJS requires destructuring. Direct require returns the module, not the class.

CacheOptions (type)

✓ import type { CacheOptions } from 'dw-cache'

✗ import { CacheOptions } from 'dw-cache'

CacheOptions is a type-only export. Use import type to avoid bundler issues in TypeScript.

Demonstrates basic cache operations: construction with limit, get/set/has/del, iteration over keys in MRU order, and clear.

import { Cache } from 'dw-cache'; // Create a cache with a limit of 1000 entries const cache = new Cache({ limit: 1000 }); // Set and get values cache.set('key1', 'value1'); console.log(cache.get('key1')); // 'value1' // Check existence and deletion console.log(cache.has('key1')); // true cache.del('key1'); console.log(cache.has('key1')); // false // Iterate over keys (order is from most recently used to least recently used) cache.set('a', 1); cache.set('b', 2); for (const key of cache) { console.log(key, cache.get(key)); } // Output: b 2, a 1 // Clear all entries cache.clear(); console.log(cache.size); // 0

Debug

Known issues

gotchaCache limit is enforced strictly; if you set a limit of 0, all entries will be evicted immediately. Ensure limit is a positive integer for meaningful caching.

fix

Always pass a limit > 0: new Cache({ limit: 1000 })

affects: >=0.0.0

deprecatedThe package is being maintained as part of the spica monorepo; future releases will be under a different package name. Monitor the spica repository for upcoming changes.

fix

Watch https://github.com/falsandtru/spica for migration instructions.

affects: >=0.0.120

gotchaThe cache does not support TTL (time-to-live) out of the box; entries remain until evicted by capacity or explicitly deleted. Do not rely on automatic expiration.

fix

Implement your own TTL wrapper or use a different caching library if TTL is required.

affects: >=0.0.0

gotchaIteration order is from most recently used to least recently used (LRU order). This is not guaranteed across versions; do not rely on the order for critical logic.

fix

Treat iteration order as informational only; avoid order-dependent algorithms.

affects: >=0.0.0

Errors

Common errors & fixes

Cannot find module 'dw-cache'

Package not installed or import path incorrect.

fix

Run 'npm install dw-cache' and ensure import uses: import { Cache } from 'dw-cache'

TypeError: dw_cache_1.Cache is not a constructor

Attempting to use default import when named export is required.

fix

Change to: import { Cache } from 'dw-cache'

ConstraintError: limit must be a positive integer

Cache created with a limit of 0 or a non-number.

fix

Pass { limit: 1000 } (or any positive integer) to the constructor.

Upgrade

Version history

0.0.120latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

45 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/falsandtru/dw-cache ↗

packagedw-cache ↗

homepagehttps://github.com/falsandtru/dw-cache ↗