Rewirte package

Author: fanatid

.gitignore

@@ -1,15 +1,5 @@
-lib-cov
-*.seed
-*.log
-*.csv
-*.dat
-*.out
-*.pid
-*.gz
-
-pids
-logs
-results
-
+.nyc_output
+coverage
 node_modules
-npm-debug.log
+
+npm-debug.log

index.js

@@ -0,0 +1,84 @@
+;(function(global) {
+  'use strict'
+
+  var nextTick = function (fn) { setTimeout(fn, 0) }
+  if (typeof process !== 'undefined' && process && typeof process.nextTick === 'function') {
+    // node.js and the like
+    nextTick = process.nextTick
+  }
+
+  function checkNumber (n) {
+    if (typeof n !== 'number' || isNaN(n) || !isFinite(n)) {
+      throw new TypeError('expected number, got ' + n)
+    }
+    if (n % 1 !== 0 || n < 1) {
+      throw new RangeError('expected positive integer number, got ' + n)
+    }
+  }
+
+  function checkFunction (f) {
+    if (typeof f !== 'function') throw new TypeError('expected function, got ' + f)
+  }
+
+  function Semaphore (capacity) {
+    if (!(this instanceof Semaphore)) {
+      return new Semaphore(capacity)
+    }
+
+    this._capacity = capacity || 1
+    checkNumber(this._capacity)
+
+    this._current = 0
+    this._queue = []
+    this._leave = this.leave.bind(this)
+  }
+
+  Semaphore.prototype.take = function () {
+    var item = {}
+    if (typeof arguments[0] === 'function') {
+      item.task = arguments[0]
+      item.n = arguments[1] || 1
+    } else {
+      item.task = arguments[1]
+      item.n = arguments[0] || 1
+    }
+
+    checkFunction(item.task)
+    checkNumber(item.n)
+    if (item.n > this._capacity) throw new RangeError('expected number in [1, ' + this._capacity + '], got ' + item.n)
+
+    if (this._current + item.n > this._capacity) {
+      this._queue.push(item)
+    } else {
+      this._current += item.n
+      item.task(this._leave)
+    }
+  }
+
+  Semaphore.prototype.leave = function (n) {
+    n = n || 1
+    checkNumber(n)
+
+    this._current = Math.max(this._current - n, 0)
+
+    if (this._queue.length === 0) return
+    if (this._current + this._queue[0].n > this._capacity) return
+
+    var item = this._queue.shift()
+    this._current += item.n
+
+    var leave = this._leave
+    nextTick(function () { item.task(leave) })
+  }
+
+  if (typeof exports === 'object') {
+    // node export
+    module.exports = Semaphore
+  } else if (typeof define === 'function' && define.amd) {
+    // amd export
+    define(function () { return Semaphore })
+  } else {
+    // browser global
+    global.semaphore = global.Semaphore = Semaphore
+  }
+}(this))