Counter By Time Bucket

A simple counter base time, is used to get counts in recent time period.

##Install:

npm install counter-by-time-bucket

##Usage: Example:

var TimeBucket = require('counter-by-time-bucket');

var timeBucket = new TimeBucket(3000,1000);


//add a to 4 in 100ms
setTimeout(function(){
   timeBucket.put('a',2);
   timeBucket.put('a',2);
},100);

//add a to 6 in 1100ms
setTimeout(function(){
   timeBucket.put('a',2);
},1100);

//add a to 7 in 2100ms
setTimeout(function(){
   timeBucket.put('a',1);
},2100);

/*
+-----+   +-----+   +-----+ 
|     |   |     |   |     | 
|  4  |   |  2  |   |  1  | 
|     |   |     |   |     | 
+-----+   +-----+   +-----+ 
0       1s        2s      3s
*/

//get last 3s a's count after 3100ms
setTimeout(function(){
   console.info(timeBucket.get('a',3000),'should be 7');
},3100);


//get last 3s a's count after 5100ms
setTimeout(function(){
   console.info(timeBucket.get('a',3000),'should be 1');
},5100);

###new TimeBucket( totalSize , bucketSize )

returns timeBucket object, you must assign totalSize and bucketSize (millisecond).

###timeBucket.put( key , value )

add value right now, value must be a number.

###timeBucket.get( key , span )

returns the key count in last span millisecond. It will throw error if span is larger than totalSize.