@keyv/compress-lz4

lz4 compression for Keyv

lz4 compression for Keyv.

lz4 is a data compression algorithm that is designed to be fast and efficient and is provided by the package lz4-napi.

Table of Contents

• Install
• Usage
• API
  • @keyv/compress-lz4([dictionary])
    • dictionary
• Migrating to v6
• License

Install

npm install --save keyv @keyv/compress-lz4

Usage

import Keyv from 'keyv';
import KeyvLz4 from '@keyv/compress-lz4';

const keyv = new Keyv({store: new Map(), compression: new KeyvLz4()});

API

@keyv/compress-lz4([dictionary])

dictionary

An optional string that lz4-napi uses as the dictionary for both compression and decompression. Use the same dictionary to read values that were written with it.

const keyv = new Keyv({ compression: new KeyvLz4('my-dictionary') });

Migrating to v6

• KeyvLz4 implements the v6 KeyvCompressionAdapter interface: compress(value: string): Promise<string> and decompress(value: string): Promise<string>. Keyv passes it the whole serialized entry, and compress returns a base64 string instead of a Uint8Array.
• The v5 serialize and deserialize methods were removed. The constructor still takes an optional dictionary string.
• Values that Keyv v5 wrote with @keyv/compress-lz4 can't be read by v6. v5 compressed only the value field inside the JSON envelope, so an old entry doesn't decode. Keyv emits error, and get returns undefined when an error listener is attached or rejects when none is. Treat a compressed store as a cache that v6 repopulates, or read the old entries with v5 and write them again with v6. See the v5 to v6 migration guide.
• Compression needs serialization, which is on by default. With serialization: false, Keyv stores values without compressing them.

License

MIT © Jared Wray