fnv-plus collision tests

index.js

var fnvplus = require('fnv-plus');

function collisionRate(bits) {
    var hashes = {};
    var texts = 0;
    var collisions = [];
    var sample = 1e6;
    while (texts < sample) {
        var text = Math.random().toString(36);
        var hash = fnvplus.hash(text,bits).hex();
        if (hashes[hash] === text) {
            continue;
        } else if (hashes[hash]) {
            collisions.push([hashes[hash], text]);
        } else {
            hashes[hash] = text;
        }
        texts++;
    }
    console.log('%d bits, collisions: %s% (%s/%s)', bits, (collisions.length/sample * 100).toFixed(3), collisions.length, sample);
}

collisionRate(32);
collisionRate(52);
collisionRate(64);

// 32 bits, collisions: 0.009% (92/1000000)
// 52 bits, collisions: 85.581% (855814/1000000)
// 64 bits, collisions: 0.000% (0/1000000)

package.json

{
    "name": "fnvplus-collisions",
    "dependencies": {
        "fnv-plus": "1.2.x"
    }
}