Utilities::convertNumberToBinaryString() - Code Metrics - Inspection of "Merge pull request #10 from unreal4u/issue/9-allow..." - unreal4u/mqtt - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 569d13...84f4c4 )

by Camilo

created 2019-04-30 22:47 UTC

Utilities::convertNumberToBinaryString() A

↳ Parent: Utilities

Complexity

Conditions	2
Paths	2

Size

Total Lines	7
Code Lines	3

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	4
CRAP Score	2

Importance

Changes

Metric	Value
eloc	3
dl	0
loc	7
c	0
b	0
f	0
ccs	4
cts	4
cp	1
rs	10
cc	2
nc	2
nop	1
crap	2

<?php

declare(strict_types=1);

namespace unreal4u\MQTT;

use LogicException;
use OutOfRangeException;
use unreal4u\MQTT\Exceptions\MessageTooBig;
use function chr;
use function dechex;
use function hexdec;
use function ord;

/**
 * Functionality that is shared across the entire package
 * @package unreal4u\MQTT
 */
final class Utilities
{
    /**
     * Swaps the given number from endian format (INT16, not to be confused with UINT16)
     *
     * @param int $number
     * @return int
     * @throws OutOfRangeException
     */
    public static function convertEndianness(int $number): int
    {
        if ($number > 65535) {
            throw new OutOfRangeException('This is an INT16 conversion, so the maximum is 65535');
        }

        $finalNumber = hexdec(
            // Invert first byte and make it a complete hexadecimal number
            str_pad(dechex($number & 255), 2, '0', STR_PAD_LEFT) .
            // Invert second byte and make a complete hexadecimal number
            str_pad(dechex($number >> 8), 2, '0', STR_PAD_LEFT)
        );

        return (int)$finalNumber;
    }

    /**
     * Converts a number to a binary string that the MQTT protocol understands
     *
     * @param int $number
     * @return string
     * @throws OutOfRangeException
     */
    public static function convertNumberToBinaryString(int $number): string
    {
        if ($number > 65535) {
            throw new OutOfRangeException('This is an INT16 conversion, so the maximum is 65535');
        }

        return chr($number >> 8) . chr($number & 255);
    }

    /**
     * Converts a binary representation of a number to an actual int
     *
     * @param string $binaryString
     * @return int
     * @throws OutOfRangeException
     */
    public static function convertBinaryStringToNumber(string $binaryString): int
    {
        return self::convertEndianness((ord($binaryString{1}) << 8) + (ord($binaryString{0}) & 255));
    }

    /**
     * Returns the correct format for the length in bytes of the remaining bytes
     *
     * Original pseudo-code algorithm as per the documentation:
     * <pre>
     * do
     *     encodedByte = X MOD 128
     *     X = X DIV 128
     *     // if there are more data to encode, set the top bit of this byte
     *     if ( X > 0 )
     *         encodedByte = encodedByte OR 128
     *     endif
     *     'output' encodedByte
     * while ( X > 0 )
     * </pre>
     * @see http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html#_Toc385349213
     *
     * @param int $lengthInBytes
     * @return string
     * @throws MessageTooBig
     */
    public static function formatRemainingLengthOutput(int $lengthInBytes): string
    {
        if ($lengthInBytes > 268435455) {
            throw new MessageTooBig('The message cannot exceed 268435455 bytes in length');
        }

        $x = $lengthInBytes;
        $outputString = '';
        do {
            $encodedByte = $x % 128;
            $x >>= 7; // Shift 7 bytes
            // if there are more data to encode, set the top bit of this byte
            if ($x > 0) {
                $encodedByte |= 128;
            }
            $outputString .= chr($encodedByte);
        } while ($x > 0);

        return $outputString;
    }

    /**
     * The remaining length of a message is encoded in this specific way, the opposite of formatRemainingLengthOutput
     *
     * Many thanks to Peter's blog for your excellent examples and knowledge.
     * @see http://indigoo.com/petersblog/?p=263
     *
     * Original pseudo-algorithm as per the documentation:
     * <pre>
     * multiplier = 1
     * value = 0
     * do
     *     encodedByte = 'next byte from stream'
     *     value += (encodedByte & 127) * multiplier
     *     if (multiplier > 128*128*128)
     *         throw Error(Malformed Remaining Length)
     *     multiplier *= 128
     * while ((encodedByte & 128) != 0)
     * </pre>
     *
     * @see http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html#_Toc385349213
     * @see Utilities::formatRemainingLengthOutput()
     *
     * @param string $remainingLengthField
     * @return int
     */
    public static function convertRemainingLengthStringToInt(string $remainingLengthField): int
    {
        $multiplier = 128;
        $value = 0;
        $iteration = 0;

        do {
            // Extract the next byte in the sequence
            $encodedByte = ord($remainingLengthField{$iteration});

            // Add the current multiplier^iteration * first half of byte
            $value += ($encodedByte & 127) * ($multiplier ** $iteration);
            if ($multiplier > 128 ** 3) {
                throw new LogicException('Malformed remaining length field');
            }

            // Prepare for the next iteration
            $iteration++;
        } while (($encodedByte & 128) !== 0);

        return $value;
    }
}


1		<?php
2
3		declare(strict_types=1);
4
5		namespace unreal4u\MQTT;
6
7		use LogicException;
8		use OutOfRangeException;
9		use unreal4u\MQTT\Exceptions\MessageTooBig;
10		use function chr;
11		use function dechex;
12		use function hexdec;
13		use function ord;
14
15		/**
16		* Functionality that is shared across the entire package
17		* @package unreal4u\MQTT
18		*/
19		final class Utilities
20		{
21		/**
22		* Swaps the given number from endian format (INT16, not to be confused with UINT16)
23		*
24		* @param int $number
25		* @return int
26		* @throws OutOfRangeException
27		*/
28	35	public static function convertEndianness(int $number): int
29		{
30	35	if ($number > 65535) {
31	1	throw new OutOfRangeException('This is an INT16 conversion, so the maximum is 65535');
32		}
33
34	34	$finalNumber = hexdec(
35		// Invert first byte and make it a complete hexadecimal number
36	34	str_pad(dechex($number & 255), 2, '0', STR_PAD_LEFT) .
37		// Invert second byte and make a complete hexadecimal number
38	34	str_pad(dechex($number >> 8), 2, '0', STR_PAD_LEFT)
39		);
40
41	34	return (int)$finalNumber;
42		}
43
44		/**
45		* Converts a number to a binary string that the MQTT protocol understands
46		*
47		* @param int $number
48		* @return string
49		* @throws OutOfRangeException
50		*/
51	34	public static function convertNumberToBinaryString(int $number): string
52		{
53	34	if ($number > 65535) {
54	1	throw new OutOfRangeException('This is an INT16 conversion, so the maximum is 65535');
55		}
56
57	33	return chr($number >> 8) . chr($number & 255);
58		}
59
60		/**
61		* Converts a binary representation of a number to an actual int
62		*
63		* @param string $binaryString
64		* @return int
65		* @throws OutOfRangeException
66		*/
67	26	public static function convertBinaryStringToNumber(string $binaryString): int
68		{
69	26	return self::convertEndianness((ord($binaryString{1}) << 8) + (ord($binaryString{0}) & 255));
70		}
71
72		/**
73		* Returns the correct format for the length in bytes of the remaining bytes
74		*
75		* Original pseudo-code algorithm as per the documentation:
76		* <pre>
77		* do
78		* encodedByte = X MOD 128
79		* X = X DIV 128
80		* // if there are more data to encode, set the top bit of this byte
81		* if ( X > 0 )
82		* encodedByte = encodedByte OR 128
83		* endif
84		* 'output' encodedByte
85		* while ( X > 0 )
86		* </pre>
87		* @see http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html#_Toc385349213
88		*
89		* @param int $lengthInBytes
90		* @return string
91		* @throws MessageTooBig
92		*/
93	18	public static function formatRemainingLengthOutput(int $lengthInBytes): string
94		{
95	18	if ($lengthInBytes > 268435455) {
96	1	throw new MessageTooBig('The message cannot exceed 268435455 bytes in length');
97		}
98
99	17	$x = $lengthInBytes;
100	17	$outputString = '';
101		do {
102	17	$encodedByte = $x % 128;
103	17	$x >>= 7; // Shift 7 bytes
104		// if there are more data to encode, set the top bit of this byte
105	17	if ($x > 0) {
106	9	$encodedByte \|= 128;
107		}
108	17	$outputString .= chr($encodedByte);
109	17	} while ($x > 0);
110
111	17	return $outputString;
112		}
113
114		/**
115		* The remaining length of a message is encoded in this specific way, the opposite of formatRemainingLengthOutput
116		*
117		* Many thanks to Peter's blog for your excellent examples and knowledge.
118		* @see http://indigoo.com/petersblog/?p=263
119		*
120		* Original pseudo-algorithm as per the documentation:
121		* <pre>
122		* multiplier = 1
123		* value = 0
124		* do
125		* encodedByte = 'next byte from stream'
126		* value += (encodedByte & 127) * multiplier
127		* if (multiplier > 128128128)
128		* throw Error(Malformed Remaining Length)
129		* multiplier *= 128
130		* while ((encodedByte & 128) != 0)
131		* </pre>
132		*
133		* @see http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/errata01/os/mqtt-v3.1.1-errata01-os-complete.html#_Toc385349213
134		* @see Utilities::formatRemainingLengthOutput()
135		*
136		* @param string $remainingLengthField
137		* @return int
138		*/
139	18	public static function convertRemainingLengthStringToInt(string $remainingLengthField): int
140		{
141	18	$multiplier = 128;
142	18	$value = 0;
143	18	$iteration = 0;
144
145		do {
146		// Extract the next byte in the sequence
147	18	$encodedByte = ord($remainingLengthField{$iteration});
148
149		// Add the current multiplier^iteration * first half of byte
150	18	$value += ($encodedByte & 127) * ($multiplier ** $iteration);
151	18	if ($multiplier > 128 ** 3) {
152		throw new LogicException('Malformed remaining length field');
153		}
154
155		// Prepare for the next iteration
156	18	$iteration++;
157	18	} while (($encodedByte & 128) !== 0);
158
159	18	return $value;
160		}
161		}
162

unreal4u / mqtt

Push — master ( 569d13...84f4c4 )

Utilities::convertNumberToBinaryString() A

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like