avoid clearing timeouts

proto.js

@@ -5,10 +5,19 @@ function Single (async, opts) {
   if(!(this instanceof Single)) return new Single(async, opts)
   this.writing = false
   this.value = null
+  this._next = 0
   this.onDrain = null
   this._async = async
   this._options = opts || {}
-  this._setTimeout = opts && opts.setTimeout || function (fn, delay) { return setTimeout(fn, delay) }
+  this._setTimeout = opts && opts.setTimeout || function (fn, delay) {
+    return setTimeout(fn, delay)
+//    if(timer1) return
+//    timer1 = setTimeout(function () {
+//      timer1 = 0
+//      clearTimeout(timer2)
+//      timer2 = setTimeout(fn, delay)
+//    }, delay/2)
+  }
 }
 
 Single.prototype.write = function (value) {
@@ -25,13 +34,18 @@ Single.prototype._write = function () {
 }
 
 Single.prototype._timeout = function (delay) {
+  delay = (delay == null ? Math.max(
+      this._options.min,
+      this._options.max - (Date.now() - this._ts)
+    ) : delay) || 10
+
+  if(this._next && this._next > Date.now() + delay/2) return
+
+  this._next = Date.now() + (delay || 10)
   clearTimeout(this._timer)
   this._timer = this._setTimeout(
     this._write.bind(this),
-    delay == null ? Math.max(
-      this._options.min,
-      this._options.max - (Date.now() - this._ts)
-    ) : delay
+    delay
   )
 }
 
@@ -69,6 +83,3 @@ and it's a different distinction from private/public.
 _cb is an update.
 */
 
-
-
-

test/bench.js

@@ -0,0 +1,52 @@
+
+
+module.exports = function (name, AsyncSingle) {
+  var called = false
+  var async = AsyncSingle(function (value, cb) {
+    called = true
+    cb(null, value)
+  }, {min: 10, max: 20})
+
+  var start = Date.now()
+  for(var i = 0; i < 500000; i++)
+    async.write(i)
+
+  console.log(name, Date.now() - start)
+}
+
+//after a couple of runs it becomes much faster because jit has kicked in
+//module.exports('closure', require('../closures'))
+//module.exports('proto', require('../proto'))
+//module.exports('closure', require('../closures'))
+//module.exports('proto', require('../proto'))
+//module.exports('proto', require('./proto'))
+
+function createClear() {
+  var timer
+  return {
+    write: function () {
+      clearTimeout(timer)
+      timer = setTimeout(function () {}, timer)
+    }
+  }
+}
+
+function createDouble() {
+  var timer
+  return {
+    write: function () {
+      if(timer) return
+      clearTimeout(timer)
+      timer = setTimeout(function () {
+        timer = null
+      }, timer)
+    }
+  }
+}
+
+
+module.exports('closure', require('../closures'))
+module.exports('proto', require('../proto'))
+module.exports('clear', createClear)
+module.exports('double', createDouble)
+