ByteNumberGenerator::initializeByteReaders() - Code Metrics - Inspection of "Use unpack instead of bin2hex" - Riimu/Kit-SecureRandom - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — unpack-change ( 9f7880 )

by Riikka

created 2017-09-09 08:43 UTC

ByteNumberGenerator::initializeByteReaders() B

↳ Parent: ByteNumberGenerator

Complexity

Conditions	1
Paths	1

Size

Total Lines	37
Code Lines	26

Duplication

Lines	16
Ratio	43.24 %

Code Coverage

Tests	35
CRAP Score	1

Importance

Changes

Metric	Value
dl	16
loc	37
ccs	35
cts	35
cp	1
rs	8.8571
c	0
b	0
f	0
cc	1
eloc	26
nc	1
nop	0
crap	1

<?php

namespace Riimu\Kit\SecureRandom\Generator;

use Riimu\Kit\SecureRandom\GeneratorException;

/**
 * A random number generator that wraps the given byte generator for generating integers.
 *
 * @author Riikka Kalliomäki <[email protected]>
 * @copyright Copyright (c) 2017 Riikka Kalliomäki
 * @license http://opensource.org/licenses/mit-license.php MIT License
 */
class ByteNumberGenerator implements NumberGenerator
{
    /** @var \Closure[] Closures for reading bytes */
    private $byteReaders;

    /** @var Generator The underlying byte generator */
    private $byteGenerator;

    /**
     * NumberByteGenerator constructor.
     * @param Generator $generator The underlying byte generator used to generate random bytes
     */
    public function __construct(Generator $generator)
    {
        $this->initializeByteReaders();
        $this->byteGenerator = $generator;
    }

    /**
     * Tells if the underlying byte generator is supported by the system.
     * @return bool True if the generator is supported, false if not
     */
    public function isSupported()
    {
        return $this->byteGenerator->isSupported();
    }

    /**
     * Returns bytes read from the provided byte generator.
     * @param int $count The number of bytes to read
     * @return string A string of bytes
     * @throws GeneratorException If there was an error generating the bytes
     */
    public function getBytes($count)
    {
        return $this->byteGenerator->getBytes($count);
    }

    /**
     * Returns a random integer between given minimum and maximum.
     * @param int $min The minimum possible value to return
     * @param int $max The maximum possible value to return
     * @return int A random number between the lower and upper limit (inclusive)
     * @throws \InvalidArgumentException If the provided values are invalid
     * @throws GeneratorException If an error occurs generating the number
     */
    public function getNumber($min, $max)
    {
        $min = (int) $min;
        $max = (int) $max;

        if ($min > $max) {
            throw new \InvalidArgumentException('Invalid minimum and maximum value');
        }

        if ($min === $max) {
            return $min;
        }

        $difference = $max - $min;

        if (!is_int($difference)) {
            throw new GeneratorException('Too large difference between minimum and maximum');
        }

        return $min + $this->getByteNumber($difference);
    }

    /**
     * Returns a random number generated using the random byte generator.
     * @param int $limit Maximum value for the random number
     * @return int The generated random number between 0 and the limit
     * @throws GeneratorException If error occurs generating the random number
     */
    private function getByteNumber($limit)
    {
        $bits = 1;
        $mask = 1;

        while ($limit >> $bits > 0) {
            $mask |= 1 << $bits;
            $bits++;
        }

        $readBytes = $this->byteReaders[(int) ceil($bits / 8)];

        do {
            $result = $readBytes() & $mask;
        } while ($result > $limit);

        return $result;
    }

    /**
     * Initializes the callbacks used to generate different numbers of bytes.
     */
    private function initializeByteReaders()
    {
        $this->byteReaders = [
            1 => function () {
                $bytes = unpack('C', $this->byteGenerator->getBytes(1));
                return $bytes[1];
            },
            2 => function () {
                $bytes = unpack('n', $this->byteGenerator->getBytes(2));
                return $bytes[1];
            },
            3 => function () {

                $bytes = unpack('Ca/nb', $this->byteGenerator->getBytes(3));
                return $bytes['a'] << 16 | $bytes['b'];
            },
            4 => function () {
                $bytes = unpack('N', $this->byteGenerator->getBytes(4));
                return $bytes[1];
            },
            5 => function () {

                $bytes = unpack('Ca/Nb', $this->byteGenerator->getBytes(5));
                return $bytes['a'] << 32 | $bytes['b'];
            },
            6 => function () {

                $bytes = unpack('na/Nb', $this->byteGenerator->getBytes(6));
                return $bytes['a'] << 32 | $bytes['b'];
            },
            7 => function () {

                $bytes = unpack('Ca/nb/Nc', $this->byteGenerator->getBytes(7));
                return $bytes['a'] << 48 | $bytes['b'] << 32 | $bytes['c'];
            },
            8 => function () {
                $bytes = unpack('J', $this->byteGenerator->getBytes(8));
                return $bytes[1];
            },
        ];
    }
}


1			<?php
2
3			namespace Riimu\Kit\SecureRandom\Generator;
4
5			use Riimu\Kit\SecureRandom\GeneratorException;
6
7			/**
8			* A random number generator that wraps the given byte generator for generating integers.
9			*
10			* @author Riikka Kalliomäki <[email protected]>
11			* @copyright Copyright (c) 2017 Riikka Kalliomäki
12			* @license http://opensource.org/licenses/mit-license.php MIT License
13			*/
14			class ByteNumberGenerator implements NumberGenerator
15			{
16			/** @var \Closure[] Closures for reading bytes */
17			private $byteReaders;
18
19			/** @var Generator The underlying byte generator */
20			private $byteGenerator;
21
22			/**
23			* NumberByteGenerator constructor.
24			* @param Generator $generator The underlying byte generator used to generate random bytes
25			*/
26	97		public function __construct(Generator $generator)
27			{
28	97		$this->initializeByteReaders();
29	97		$this->byteGenerator = $generator;
30	97		}
31
32			/**
33			* Tells if the underlying byte generator is supported by the system.
34			* @return bool True if the generator is supported, false if not
35			*/
36	3		public function isSupported()
37			{
38	3		return $this->byteGenerator->isSupported();
39			}
40
41			/**
42			* Returns bytes read from the provided byte generator.
43			* @param int $count The number of bytes to read
44			* @return string A string of bytes
45			* @throws GeneratorException If there was an error generating the bytes
46			*/
47	12		public function getBytes($count)
48			{
49	12		return $this->byteGenerator->getBytes($count);
50			}
51
52			/**
53			* Returns a random integer between given minimum and maximum.
54			* @param int $min The minimum possible value to return
55			* @param int $max The maximum possible value to return
56			* @return int A random number between the lower and upper limit (inclusive)
57			* @throws \InvalidArgumentException If the provided values are invalid
58			* @throws GeneratorException If an error occurs generating the number
59			*/
60	41		public function getNumber($min, $max)
61			{
62	41		$min = (int) $min;
63	41		$max = (int) $max;
64
65	41		if ($min > $max) {
66	3		throw new \InvalidArgumentException('Invalid minimum and maximum value');
67			}
68
69	38		if ($min === $max) {
70	12		return $min;
71			}
72
73	29		$difference = $max - $min;
74
75	29		if (!is_int($difference)) {
76	2		throw new GeneratorException('Too large difference between minimum and maximum');
77			}
78
79	27		return $min + $this->getByteNumber($difference);
80			}
81
82			/**
83			* Returns a random number generated using the random byte generator.
84			* @param int $limit Maximum value for the random number
85			* @return int The generated random number between 0 and the limit
86			* @throws GeneratorException If error occurs generating the random number
87			*/
88	27		private function getByteNumber($limit)
89			{
90	27		$bits = 1;
91	27		$mask = 1;
92
93	27		while ($limit >> $bits > 0) {
94	27		$mask \|= 1 << $bits;
95	27		$bits++;
96	9		}
97
98	27		$readBytes = $this->byteReaders[(int) ceil($bits / 8)];
99
100			do {
101	27		$result = $readBytes() & $mask;
102	27		} while ($result > $limit);
103
104	27		return $result;
105			}
106
107			/**
108			* Initializes the callbacks used to generate different numbers of bytes.
109			*/
110	97		private function initializeByteReaders()
111			{
112	97		$this->byteReaders = [
113	64		1 => function () {
114	24		$bytes = unpack('C', $this->byteGenerator->getBytes(1));
115	24		return $bytes[1];
116	97		},
117	64		2 => function () {
118	6		$bytes = unpack('n', $this->byteGenerator->getBytes(2));
119	6		return $bytes[1];
120	97		},
121	64	View Code Duplication	3 => function () {
			0 ignored issues – show Duplication introduced 2017-09-09 08:45 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
122	6		$bytes = unpack('Ca/nb', $this->byteGenerator->getBytes(3));
123	6		return $bytes['a'] << 16 \| $bytes['b'];
124	97		},
125	64		4 => function () {
126	3		$bytes = unpack('N', $this->byteGenerator->getBytes(4));
127	3		return $bytes[1];
128	97		},
129	64	View Code Duplication	5 => function () {
			0 ignored issues – show Duplication introduced 2017-09-09 08:45 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
130	3		$bytes = unpack('Ca/Nb', $this->byteGenerator->getBytes(5));
131	3		return $bytes['a'] << 32 \| $bytes['b'];
132	97		},
133	64	View Code Duplication	6 => function () {
			0 ignored issues – show Duplication introduced 2017-09-09 08:45 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
134	3		$bytes = unpack('na/Nb', $this->byteGenerator->getBytes(6));
135	3		return $bytes['a'] << 32 \| $bytes['b'];
136	97		},
137	64	View Code Duplication	7 => function () {
			0 ignored issues – show Duplication introduced 2017-09-09 08:45 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
138	3		$bytes = unpack('Ca/nb/Nc', $this->byteGenerator->getBytes(7));
139	3		return $bytes['a'] << 48 \| $bytes['b'] << 32 \| $bytes['c'];
140	97		},
141	97		8 => function () {
142	6		$bytes = unpack('J', $this->byteGenerator->getBytes(8));
143	6		return $bytes[1];
144	97		},
145			];
146	33		}
147			}
148

Riimu / Kit-SecureRandom

Push — unpack-change ( 9f7880 )

ByteNumberGenerator::initializeByteReaders() B

Complexity

Size

Duplication

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