Delay Queue first cut

zenwalk · Oct 3, 2013 · ad3ce8d · ad3ce8d
1 parent 9158e94
commit ad3ce8d
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diff --git a/lib/DelayQueue.js b/lib/DelayQueue.js
@@ -0,0  1,33 @@
 (function () {
     "use strict";
     var PriorityQueue = require('./PriorityQueue');
 
     function DelayQueue(delayFn) {
         if(typeof delayFn!=='function') {
             throw new Error('A delay function must be provided to construct'  
                 'a DelayQueue');
         }
         this._delayFn=delayFn;
         PriorityQueue.call(this,function (inQ, objToAdd) {
             var dInQ = delayFn.call(null, inQ),
                 dObjToAdd = delayFn.call(null, objToAdd);
             return dInQ > dObjToAdd ?
                 1 : dInQ < dObjToAdd ?
                 -1 : 0;
 
         });
     }
 
     DelayQueue.prototype=new PriorityQueue();
     var _super=PriorityQueue.prototype;
 
     DelayQueue.prototype.poll=function(){
         var head=this.peek();
         return this._delayFn(head)<=0?
              _super.poll.call(this):null;
     };
 
 
     module.exports = DelayQueue;
 
 }());
diff --git a/tests/TestDelayQueue.js b/tests/TestDelayQueue.js
@@ -0,0  1,86 @@
 var DelayQueue = require('../lib/DelayQueue.js'), assert = require('assert'), fs = require('fs');
 (function () {
 
     function testOffer(testDoneFn) {
         console.log('**testOffer***');
         var times = [Date.now()   10 * 1000, Date.now()   20 * 1000, Date.now()   30 * 1000, Date.now()   40 * 1000]
         var tasks = [
             {'schedule' : times[0]},
             {'schedule' : times[1]},
             {'schedule' : times[3]},
             {'schedule' : times[2]}
         ];
         var dq = new DelayQueue(function (task) {
             return task.schedule - Date.now();
         });
         tasks.forEach(function (task) {
             dq.offer(task);
         });
         assert.deepEqual(dq._queue, [
             { schedule : times[0] },
             { schedule : times[1] },
             { schedule : times[3] },
             { schedule : times [2]}
         ]);
 
         assert.equal(dq.size(), 4);
         assert.equal(dq.poll(), null);
         assert.equal(dq.peek().schedule, times[0]);
         setTimeout(function () {
             assert.deepEqual(dq.poll().schedule, times[0]);
             assert.equal(dq.poll(), null);
             testDoneFn();
         }, 12000);
     }
 
     function testPoll() {
         console.log('**** test Poll***');
         var times = [],
             delay = 2000,
             now = Date.now();
         var dq = new DelayQueue(function (task) {
             return task.schedule - Date.now();
         });
 
         for (var i = 30; i > 0; i--) {
             var time = (now   delay * i);
             times[i] = time;
             dq.offer({'schedule' : time});
         }
 
         function testCleanup() {
             //clean and check
             for (i = 21; i <= 30; i  ) {
                 dq.poll();
             }
             assert.equal(dq.size(), 0);
             assert.deepEqual(dq._queue, []);
         }
 
         setTimeout(function () {
             for (i = 1; i <= 20; i  ) {
                 //console.log('iteration '   i);
                 assert.equal(dq.poll().schedule, times[i]);
                 assert.equal(dq.size(), 30 - i, 'test failed - size mismatch');
 
 
             }
             for (i = 9; i >= 0; i--) {
                 assert.equal(dq.peek().schedule, times[21]);
                 assert.equal(dq.size(), 10, 'test failed - size mismatch');
             }
             setTimeout(testCleanup, 20 * 1000);
 
         }, 42 * 1000);
 
 
     }
 
 
     testOffer(function () {
         testPoll();
     });
 
 
 
 }());