another user queue example, similar to how the Redis protocol works

README.md

requests come in e.g. /foo

replies come out upper-cased as /FOO

however, they are sent over to db.js to get upper-cased, and it replies two at once, concatenated with \n to delimit

when a reply comes back from db.js it sends both queued replies back to the HTTP clients at the same time, i.e. the first will wait until the second comes in.

db.js

// Wait until there are two queries, then reply to both, newline-concatenated
var net = require('net')

var s = net.createServer((c) => {
  // for this test, assuming data won't be chunked here
  var pending = []
  function checkDone() {
    if (pending.length == 2) {
      c.write(pending.join('\n') + '\r\n')
      pending = []
    }
  }
  c.on('data', (chunk) => {
    var message = chunk.slice(0, chunk.length - 2).toString().toUpperCase()
    pending.push(message)
    c.write('OK\r\n')
    checkDone()
  })
})
s.listen(7000)

gistfile1.txt

bryce@x1c:~/ns$ curl http://localhost:8000/foo
/FOO

bryce@x1c:~/ns$ curl http://localhost:8000/bar
/BAR

server.js

var http = require('http')
var net = require('net')

var c = net.connect(7000)
c.on('data', checkReply)

var queued = []
function checkReply(chunk) {
  // for this test, assuming data won't be chunked here
  var message = chunk.slice(0, chunk.length - 2).toString()
  if (message == 'OK') {
    return
  }
  var replies = message.split('\n')
  for (var i = 0; i < queued.length; i++) {
    var fn = queued[i]
    setImmediate(fn.bind(fn, replies[i]))
  }
  queued = []
}

function enqueue(data, cb) {
  c.write(data + '\r\n')
  queued.push(cb)
}

var s = http.createServer((req, res) => {
  enqueue(req.url, (reply) => {
    res.end(reply + '\n')
  })
})
s.listen(8000)