JAAulde\IP\V4\SubnetMask

Complexity

Total Complexity

8

Size/Duplication

Total Lines	67
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	1

Importance

Changes	7
Bugs	0	Features	0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	getHostBitsCount()	0	4	1
A	getNetworkBitsCount()	0	4	1
A	getCIDRPrefix()	0	4	1
A	calculateCIDRToFit()	0	4	1
A	fromCIDRPrefix()	0	12	4

<?php

namespace JAAulde\IP\V4;

/**
 * Represents an IP(V4) subnet mask.
 *
 * @author Jim Auldridge <auldridgej@gmail.com>
 * @copyright 2006-2015 Jim Auldridge
 * @license MIT
 */
class SubnetMask extends Address
{
    /**
     * Retrieve the number of host bits denoted by this mask.
     *
     * @return int
     */
    public function getHostBitsCount()
    {
        return 32 - $this->getNetworkBitsCount();
    }

    /**
     * Retrieve the number of network bits denoted by this mask.
     *
     * @return int
     */
    public function getNetworkBitsCount()
    {
        return (int) (32 - log(($this->get() ^ ip2long('255.255.255.255')) + 1, 2));
    }

    /**
     * Alias to \JAAulde\IP\V4\SubnetMask::getNetworkBitsCount.
     *
     * @uses \JAAulde\IP\V4\SubnetMask::getNetworkBitsCount
     *
     * @return int
     */
    public function getCIDRPrefix()
    {
        return $this->getNetworkBitsCount();
    }

    /**
     * Given two (2) IP (V4) addresses, calculate a CIDR prefix for the network which could contain them both.
     *
     * @param \JAAulde\IP\V4\Address $address1
     * @param \JAAulde\IP\V4\Address $address2
     */
    public static function calculateCIDRToFit(Address $address1, Address $address2)
    {
        return (int) floor(32 - log(($address1->get() ^ $address2->get()) + 1, 2));
    }

    /**
     * Factory method for producing a SubnetMask instance from a CIDR (slash notation) prefix size.
     *
     * @param int $prefixSize Number of network bits to be represented by the subnet mask
     *
     * @return self
     *
     * @throws Exception
     */
    public static function fromCIDRPrefix($prefixSize)
    {
        if (!is_int($prefixSize)) {
            throw new \Exception(__METHOD__.' requires first param, $prefixSize, to be an integer');
        }

        if ($prefixSize < 1 || $prefixSize > 31) {
            throw new \Exception(__METHOD__.' requires first param, $prefixSize, to be CIDR prefix size with value between 1 and 31 (inclusive)');
        }

        return new self(bindec(str_repeat('1', $prefixSize).str_repeat('0', 32 - $prefixSize)));
    }
}