node-kv-storage

Node KV Storage

Wrapper around node-persist that implements the std:kv-storage interface.

Why

• Standardized API
• Easier code sharing with frontend
• No await init()

How

const storage = require('node-kv-storage')

;(async () => {
  await storage.set('test', { a: 3 })
  console.log(await storage.get('test'))

  // Compatible with node-persist for string and binary keys
  await require('node-persist').init()
  await require('node-persist').setItem('foo', { b: 4 })
  console.log(await storage.get('foo'))

  await require('node-persist').setItem(Buffer.from([0x1, 0x2]), { d: 6 })
  console.log(await storage.get(Buffer.from([0x1, 0x2])))
  
  // Also allows Number keys
  await storage.set(3, { f: 8 })
  console.log(await storage.get(3))

  // Also allows Date keys
  const d = new Date(0)
  await storage.set(d, { c: 5 })
  console.log(await storage.get(d))

  // Use multiple storage areas
  const { StorageArea } = storage
  const other = new StorageArea('other_area')
  await other.set('test', { i: 11 })
  console.log(await other.get('test'))
})()

API

• Google Developers Tutorial
• Spec

Limitations

• Since there is no IndexedDB in node, backingStore is not implemented.
• Using typed arrays as keys works, but when using keys() or entries() they will be returned in the form JSON.parse(JSON.stringify(yourTypedArray)). Typically this will look like { '0': 255, '1': 255, ... }.
• Storage areas with the name default and storage will both map to the directory storage.

Questions

How do I change the storage directory?

node-persist provides the dir option to specify the directory in which to write files. The KV Storage proposal intended for browsers has no such option, and for compatibility this library doesn't provide this option either. In my opinion, providing the file path as configuration option is bad idea anyway, instead node-kv-storage takes inspiration form the Twelve Factor App takes the base directory from the environment variable NODE_KV_STORAGE_DIR.

How do I change the serialization / deserialization ?

Currently not implemented