output.txt

$ node stream-heap.js

Readable 358.53592 134
Writable 623.37824 258
Transform 709.05584 1310

$ node pull-heap.js

values 155.2692 70
map 84.50328 7
drain 203.86776 73

$ node push-heap.js

Values 63.6348 31
Map 103.9844 45
Collect 112.44888 10

pull-heap.js

var pull = require('pull-stream')

function heap (name, Stream) {
  var start = Date.now()
  var heap = process.memoryUsage().heapUsed
  var a = [], N = 100000
  for(var i = 0; i < N; i++)
    a.push(Stream())
  console.log(name, (process.memoryUsage().heapUsed - heap)/N, (Date.now()-start))
  a = null
}

heap('values', pull.values)
heap('map', pull.map)
heap('drain', pull.drain)

push-heap.js

function heap (name, Stream) {
  var start = Date.now()
  var heap = process.memoryUsage().heapUsed
  var a = [], N = 100000
  for(var i = 0; i < N; i++)
    a.push(new Stream())
  console.log(name, (process.memoryUsage().heapUsed - heap)/N, (Date.now()-start))
  a = null
}

heap('Values', require('push-stream--/values'))
heap('Map', require('push-stream--/async'))
heap('Collect', require('push-stream--/collect'))

stream-heap.js

var streams = require('stream')
function heap (name, Stream) {
  var start = Date.now()
  var heap = process.memoryUsage().heapUsed
  var a = [], N = 100000
  for(var i = 0; i < N; i++)
    a.push(new Stream())
  console.log(name, (process.memoryUsage().heapUsed - heap)/N, (Date.now()-start))
  a = null
}

heap('Readable', streams.Readable)
heap('Writable', streams.Writable)
heap('Transform', streams.Transform)

!!! creating 100k empty transform streams takes over a second !!!