maxwilms\BloomFilter\Hash\MultiHash

Complexity

Total Complexity

7

Size/Duplication

Total Lines	59
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	3

Importance

Changes

0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	16	3
A	setUpperBound()	0	4	1
A	setHashCount()	0	4	1
A	hash()	0	13	2

<?php

namespace maxwilms\BloomFilter\Hash;

class MultiHash
{

    protected $hashOne;

    protected $hashTwo;

    protected $upperBound;

    protected $hashCount;

    public function __construct(Hash $hashOne = null, Hash $hashTwo = null)
    {
        if ($hashOne === null) {
            $hashOne = new JoaatHash();
        }

        if ($hashTwo === null) {
            $hashTwo = new FNVHash();   
        }
        
        $this->hashOne = $hashOne;
        $this->hashTwo = $hashTwo;

        $this->upperBound = 0x0ffffffff;
        $this->hashCount = 3;
    }

    public function setUpperBound($upperBound)
    {
        $this->upperBound = $upperBound;
    }

    public function setHashCount($hashCount)
    {
        $this->hashCount = $hashCount;
    }

    /**
     * hash(i) = (a + b * i ) % m
     *
     * @param $string
     * @return array
     */
    public function hash($string)
    {
        $hashes = [];

        $a = $this->hashOne->hash($string);
        $b = $this->hashTwo->hash($string);

        for ($i = 1; $i <= $this->hashCount; $i++) {
            $hashes[] = ($a + $b * $i) % $this->upperBound;
        }

        return $hashes;
    }

}