const Sleepfile = require('sleepfile')
const ram = require('random-access-memory')
const file = new Sleepfile(ram())
file.put(42, Buffer.alloc(42), function (err) {
  console.log('Inserted an entry at index 42')
  file.get(42, function (err, buf) {
    console.log('Read it out again')
  })
})

{
  magicBytes: 0x00000000, // set a magic bytes header of the file
  valueSize: 42, // explicitly set the valueSize (infered on first put otherwise)
  valueEncoding: encoding, // optionally set an abstract-encoding for the values
  name: 'algo', // optionally set the algorithm name in the header
  overwrite: false // reset the file content
}

{
  magicBytes: 0x00000000, // the magic bytes stored
  version: 0, // sleep version
  valueSize: 42,
  name: 'algo name',
  length: 42, // how many values are there maximum
  density: 0.60 // how much of the underlying storage are actually in use
}