Native HyperLogLog for node.js

See http://en.wikipedia.org/wiki/HyperLogLog.

Based on https://github.com/avz/hll.

Example

varHLL=require('hll-native').HLL;vartries=5;for(varn=0;n<tries;n++){varstart=Date.now();varo={};varobj=newHLL(20);for(vari=0;i<10000000;i++){obj.add('hello_'+i);}console.log('['+(n+1)+' / '+tries+']','Approximated set size:',obj.count()+'.','Elapsed time:',Date.now()-start,'ms');}

[1 / 5] Approximated set size: 10000341. Elapsed time: 2142 ms
[2 / 5] Approximated set size: 10000341. Elapsed time: 2133 ms
[3 / 5] Approximated set size: 10000341. Elapsed time: 2142 ms
[4 / 5] Approximated set size: 10000341. Elapsed time: 2121 ms
[5 / 5] Approximated set size: 10000341. Elapsed time: 2118 ms

Memory usage and error values

bits	size (bytes)	standard error
4	16	26.00%
5	32	18.38%
6	64	13.00%
7	128	9.19%
8	256	6.50%
9	512	4.60%
10	1024	3.25%
11	2048	2.30%
12	4096	1.62%
13	8192	1.15%
14	16384	0.81%
15	32768	0.57%
16	65536	0.41%
17	131072	0.29%
18	262144	0.20%
19	524288	0.14%
20	1048576	0.10%

Prototype

/** * Create new HyperLogLog storage with specified size and standard error. * * Memory usage for storage calculated as (1 << bits) bytes. * Standard error described in table above * * @param {number} bits */varHLL=function(bits){};/** * Add key to storage * @param {string} key */HLL.prototype.add=function(key){};/** * Get approximated set size with selected standard error * @returns {number} */HLL.prototype.count=function(){};