ordered-kv-tuple-stream

ordered-kv-tuple-stream aligns multiple ordered {key, value} readable streams (as provided by levelup's createReadStream, for example) into a single ordered stream of {key, value} tuples.

Example

import {Readable} from "stream"
import OrderedKVTupleStream from "ordered-kv-tuple-stream"

let hours = {
  before: Readable({objectMode: true}),
  after: Readable({objectMode: true})
}

hours.before.push({key: "FRI", value: "10-7pm"})
hours.before.push({key: "SAT", value: "10-7pm"})
hours.before.push(null)

hours.after.push({key: "SAT", value: "10-9pm"})
hours.after.push({key: "SUN", value: "10-7pm"})
hours.after.push(null)

OrderedKVTupleStream(hours).on("data", console.log)

// { key: 'FRI', value: { before: '10-7pm' } }
// { key: 'SAT', value: { before: '10-7pm', after: '10-9pm' } }
// { key: 'SUN', value: { after: '10-7pm' } }

Installation

npm install ordered-kv-tuple-stream

API

let stream = OrderedKVTupleStream(streamTuple)

Takes a streamTuple object for which all keys have readable {key, value} streams as values, and returns a readable stream that emits aligned {key, value} objects. Emitted keys are a union of all original keys and emitted values are tuples whose keys match those of streamTuple.