Registry / storage / redis-value-cache

redis-value-cache

library1.1.0jsnpmunverified

An in-memory cache backed by Redis with pub/sub updates, version 1.1.0. Designed for applications needing low-latency access to Redis-stored data with real-time invalidation. Uses an LRU cache internally, supports key generation and deserialization functions, and offers multiple error handling and update strategies. Unlike simple Redis caching, it subscribes to channels to automatically update or evict cached items upon data changes, reducing server load and ensuring freshness. Suitable for TypeScript projects, ships types, and requires a Redis server for reading and pub/sub.

storage

npm install redis-value-cache

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · REDIS-VALUE-CACHE

redis-value-cache

storagejavascriptv1.1.0

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.

RedisValueCache

✓ import { RedisValueCache } from 'redis-value-cache'

✗ import RedisValueCache from 'redis-value-cache'

Named export only, not default. ESM and TypeScript compatible.

RedisValueCacheOptions

✓ import { RedisValueCacheOptions } from 'redis-value-cache'

TypeScript type for constructor options. Also importable via this path.

RedisGetOpts

✓ import { RedisGetOpts } from 'redis-value-cache'

Type for specifying GET, HGET, or HGETALL retrieval strategy, used in genKeyFromMsg return value.

ErrorHandlerStrategy

✓ import { ErrorHandlerStrategy } from 'redis-value-cache'

String union type for error handling options: 'emit' | 'warn' | 'throw' | 'ignore'.

Creates a RedisValueCache with a shared Redis client, subscribes to pattern 'cache:*', gets values via GET, and deserializes JSON.

import { RedisValueCache } from 'redis-value-cache'; import { createClient } from 'redis'; const client = createClient({ url: process.env.REDIS_URL ?? 'redis://localhost:6379' }); await client.connect(); const cache = new RedisValueCache({ redis: { client, // reuse for subscriber and client channelOpts: { pattern: 'cache:*' }, getOpts: { type: 'GET' } }, genKeyFromMsg: (message) => message, deserialize: (data: string | null) => data ? JSON.parse(data) : undefined, cacheMaxSize: 500, onMessageStrategy: 'drop', freeze: true }); await cache.init(); // subscribe to Redis const value = await cache.get('user:123'); console.log(value); await cache.close();

Debug

Known issues

breakingValues must not be null or undefined. Cache will ignore such values silently.

fix

Ensure deserialize never returns null/undefined; handle in fallbackFetchMethod if needed.

affects: >=1.0.0

gotchafreeze: true by default. Mutating cached objects throws in strict mode or silently fails.

fix

Set freeze: false if you need to mutate cached objects.

affects: >=1.0.0

gotchaErrors in genKeyFromMsg or deserialize are not thrown by default; they are handled by errorHandlerStrategy (default 'warn').

fix

Set errorHandlerStrategy: 'throw' during development to catch errors early.

affects: >=1.0.0

deprecatedThe 'fallbackFetchMethod' option is experimental and may change in minor versions.

fix

Use with caution; test upgrade paths when releasing new versions.

affects: >=1.0.0 <2.0.0

breakinginit() must be called before get(). Calling get() before init() may hang or fail.

fix

Always await cache.init() before any get() calls.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: client.duplicate is not a function

You passed a client object that doesn't have duplicate() method (e.g., older Redis client or mock).

fix

Provide a proper ioredis or node-redis client, or supply redis.clientOpts instead of a raw client.

Error: The subscribed channel is not active

RedisValueCache expects the client to be connected before subscribing, but it wasn't initialized properly.

fix

Await client.connect() before passing to RedisValueCache, or pass redis.clientOpts to let the library handle connection.

RedisValueCache: message received but genKeyFromMsg returned undefined

genKeyFromMsg function returned undefined, so the message was ignored without updating cache.

fix

Ensure genKeyFromMsg always returns a string key; log or handle cases where it might return undefined.

RedisValueCache: error during fetch, ignoring: TimeoutError

The errorHandlerStrategy is set to 'ignore' (default 'warn' if not set) and a Redis timeout occurred.

fix

Set errorHandlerStrategy: 'throw' or 'emit' to handle errors, or increase Redis timeout.

Upgrade

Version history

1.1.0latest on npm

Audit

Dependencies

redisrequiredPeer dependency for Redis client operations (subscribe, GET, HGET, HGETALL). Required at runtime.

Agent activity

26 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/tcs-de/redis-value-cache ↗

packageredis-value-cache ↗

homepagehttps://github.com/tcs-de/redis-value-cache#readme ↗