node-hll

This is a native HyperLogLog lib (A wrap for avz/hll).

matcha benchmark result

                      HLL
      12,555,981 op/s » add const string
      11,999,272 op/s » add const buffer
       5,545,313 op/s » add cnt++
       2,477,867 op/s » add random
       1,380,207 op/s » toBuffer
           6,964 op/s » intersection

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% |

Example

const HLL = require('node-hll');

const hll = new HLL(5);

// Add item to hll counter.
hll.add('1');
hll.add(new Buffer('2'));

console.log(hll.bits);
console.log(hll.count());
console.log(hll.toBuffer());

// Create HLL from buffer.
console.log(new HLL(hll.toBuffer()).count());

const hll2 = new HLL(5);
hll2.add('3');
hll2.merge(hll);
console.log(hll2.count());

const hll3 = new HLL(5);
hll3.add('8');
hll3.add('1');

console.log(HLL.intersectionSize([hll, hll2]));
console.log(HLL.intersectionSize([hll, hll2, hll3]));