atomic-batcher

A simple batching function that allows you to atomically batch a series of operations. If you are looking for the same thing with a stream interface checkout byte-stream.

npm install atomic-batcher

Usage

var batcher = require('atomic-batcher')
var db = require('level')('some.db')
 
var batch = batcher(function work (ops, cb) {
  // only one batch will happen at the time
  console.log('Batching:', ops, '\n')
  db.batch(ops, cb)
})
 
batch({type: 'put', key: 'hello', value: 'world-1'})
batch({type: 'put', key: 'hello', value: 'world-2'})
batch({type: 'put', key: 'hello', value: 'world-3'})
batch({type: 'put', key: 'hi', value: 'hello'}, function () {
  console.log('Printing latest values:\n')
  db.get('hello', console.log) // returns world-3
  db.get('hi', console.log) // returns hello
})

Running the above example will print

Batching: [ { type: 'put', key: 'hello', value: 'world-1' } ]

Batching: [ { type: 'put', key: 'hello', value: 'world-2' },
  { type: 'put', key: 'hello', value: 'world-3' },
  { type: 'put', key: 'hi', value: 'hello' } ]

Printing latest values:

null 'world-3'
null 'hello'

API

var batch = batcher(worker)

Create a new batching function. worker should be a function that accepts a batch and a callback, (batch, cb). Only one batch is guaranteed to be run at the time.

The batch function accepts a value or an array of values and a callback, batch(value(s), cb). The callback is called when the batch containing the values have been run.

License

MIT