@qiwi/primitive-storage

kv storage for basic purposes

Motivation

In 2018 2023 it's easier to write own storage implementation than to find a suitable one.

• memory-cache is good enough, but setTimeout for each entry set looks redundant (0.2.0)
• data-store — very nice, but only synchronous saving is supported, no debouncing, no ttl (2.0.1)
• node-cache — pretty OK. Callbacks and events are supported. But no JSON.stringify handling, no persistency out of box (4.2.0)
• CacheFactory — brilliant. localStorage, api, docs — everything is ok, but there's no file saving mechanism.

What's needed

• Key-Value scheme
• Optional TTL with scheduled compaction
• Optional value cloning
• Cycled refs handling (JSON.safeStringify, you know)
• Sync throttling
• Both browser and server runtimes support

Install

    npm i @qiwi/primitive-storage
    yarn add @qiwi/primitive-storage

JS/TS API

interface IStorage {
  get(key: string): any,
  set(key: string, value: any, ttl?: number): void,
  remove(key: string): void,
  reset(): void
}

import factory from '@antongolub/primitive-storage'

const storage = factory({defaultTtl: 60000})

storage.set('foo', 'bar')
storage.get('foo')  // 'bar'

// A minute later
storage.get('foo')  // undefined

Common aliases were also added for convenience:

• put = set
• del = remove
• clear = reset

Configuration

Option	Type	Def	Description
defaultTtl	number	-	If defined, the value would be applied as default ttl for every set() call
debounce	Object	-	Options for persistent storage sync debounce. If empty no delay processed. IDebounceOpts: {    delay: number,    maxDelay?: number,    leading?: boolean    trailing?: boolean }
path	string	-	Filepath (NodeJS) or localStorage scope (Browser)
compactTimer	number	-	Period (ms) of automated compact method invocation If undefined, no periodic task is running
clone	bool/fn	false	true means that values are copied to storage on set. Default copier (JSON.parse(JSON.str(...))) may be replaced with custom.

Persistent data

It's very simple: if path property declared in opts, the data is being persisted:

• In case of NodeJS runtime, the data would be saved as json file.
• Browser relies on localStorage API.

    const storage = factory({path: './data.json'})

Compaction

Current impl is dumb: every n milliseconds the job filters out expired entries from the storage. You're able to set compactTimer in storage opts, or just trigger compact method by hand.

License

MIT