secondary-cache

library2.1.1jsnpmunverified

A two-tier cache library with a fixed-capacity first-level (memory-resident) cache and an LRU second-level cache. Version 2.1.1 is current, stable, and ships TypeScript definitions. Differentiators include configurable expiration, weight-based eviction, and event hooks (before_add, add, update, del). It is lightweight with no external dependencies, suitable for Node.js or browser environments.

storage

npm install secondary-cache

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · SECONDARY-CACHE

secondary-cache

storagejavascriptv2.1.1

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 'secondary-cache'

✗ const Cache = require('secondary-cache').Cache

Both ES and CommonJS are supported, but named import is preferred.

LRUCache

✓ import { LRUCache } from 'secondary-cache'

✗ import LRUCache from 'secondary-cache'

LRUCache is a named export, not default.

type CacheOptions

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

✗ import { CacheOptions } from 'secondary-cache'

CacheOptions is a TypeScript interface, use type-only import when not needing values.

CacheEvent

✓ import { CacheEvent } from 'secondary/cache'

CacheEvent is exported from a subpath. Ensure correct path.

Demonstrates basic usage of Cache with fixed and LRU tiers, expiration, events, and deletion.

import { Cache } from 'secondary-cache'; const cache = new Cache({ fixedCapacity: 10, capacity: 100 }); cache.set('key', 'value'); const val = cache.get('key'); console.log(val); // 'value' // With expiration cache.set('temp', 'data', 5000); // expires in 5 seconds // Listen to events cache.on('add', (key) => console.log(`Added ${key}`)); // Check existence if (cache.has('key')) { cache.delete('key'); }

Debug

Known issues

gotchaIf capacity is set to 0 or not provided, the LRU cache is disabled; only fixed cache operates.

fix

Ensure capacity > 0 to enable secondary LRU caching.

affects: >=2.0.0

gotchaThe 'expires' option is in milliseconds, not seconds.

fix

Multiply seconds by 1000 when providing expiration time.

affects: >=2.0.0

gotchacleanInterval expects seconds, not milliseconds.

fix

Provide cleanInterval in seconds (e.g., 60 for 1 minute).

affects: >=2.0.0

deprecatedMethod 'isExist' and 'isExists' are deprecated in favor of 'has'.

fix

Use cache.has(id) instead.

affects: >=2.0.0

gotchaEvents are emitted synchronously; adding listeners after cache operations will miss events.

fix

Attach event listeners before any cache.set() calls.

affects: >=2.0.0

breakingVersion 2.x changed the options structure: 'capacity' now refers to second-level LRU capacity; 'fixedCapacity' is for first-level.

fix

Update config objects: { fixedCapacity: N, capacity: M }.

affects: <2.0.0

Errors

Common errors & fixes

TypeError: cache.on is not a function

Events are an optional feature; you must check if cache is an EventEmitter.

fix

Cache instances extend EventEmitter; ensure you are using the correct import and the version supports events.

Error: maxWeight exceeded

An item's weight exceeds the configured maxWeight.

fix

Adjust maxWeight or override weightOf function to assign appropriate weights.

TypeError: Cannot read properties of undefined (reading 'set')

Cache instance not properly initialized or imported incorrectly.

fix

Use import { Cache } from 'secondary-cache' and instantiate with 'new Cache()'.

Warning: cleanInterval less than 1, disabling background cleanup.

cleanInterval set to 0 or negative.

fix

Set cleanInterval to a positive integer (in seconds) to enable background cleanup, or omit if not needed.

Upgrade

Version history

2.1.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

32 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/snowyu/secondary-cache.js ↗

packagesecondary-cache ↗

homepagehttps://github.com/snowyu/secondary-cache.js ↗