APILengthCoDec::decodeLength() - Code Metrics - Inspection of "Streamrefactor" - EvilFreelancer/routeros-api-php - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#8)

by Mr

created 2019-03-24 11:53 UTC

APILengthCoDec::decodeLength() B

↳ Parent: APILengthCoDec

Complexity

Conditions	7
Paths	7

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	32
CRAP Score	7

Importance

Changes

Metric	Value
dl	0
loc	92
ccs	32
cts	32
cp	1
rs	7.2412
c	0
b	0
f	0
cc	7
nc	7
nop	1
crap	7

How to fix Long Method

<?php

namespace RouterOS;

use RouterOS\Interfaces\StreamInterface;
use RouterOS\Helpers\BinaryStringHelper;

/**
 * class APILengthCoDec
 *
 * Coder / Decoder for length field in mikrotik API communication protocol
 *
 * @package RouterOS
 * @since   0.9
 */
class APILengthCoDec
{
    public static function encodeLength(int $length): string
    {
        // Encode the length :
        // - if length <= 0x7F (binary : 01111111 => 7 bits set to 1)
        //      - encode length with one byte
        //      - set the byte to length value, as length maximal value is 7 bits set to 1, the most significant bit is always 0
        //      - end
        // - length <= 0x3FFF (binary : 00111111 11111111 => 14 bits set to 1)
        //      - encode length with two bytes
        //      - set length value to 0x8000 (=> 10000000 00000000)
        //      - add length : as length maximumal value is 14 bits to 1, this does not modify the 2 most significance bits (10)
        //      - end
        //      => minimal encoded value is 10000000 10000000
        // - length <= 0x1FFFFF (binary : 00011111 11111111 11111111 => 21 bits set to 1)
        //      - encode length with three bytes
        //      - set length value to 0xC00000 (binary : 11000000 00000000 00000000)
        //      - add length : as length maximal vlaue is 21 bits to 1, this does not modify the 3 most significance bits (110)
        //      - end
        //      => minimal encoded value is 11000000 01000000 00000000
        // - length <= 0x0FFFFFFF (binary : 00001111 11111111 11111111 11111111 => 28 bits set to 1)
        //      - encode length with four bytes
        //      - set length value to 0xE0000000 (binary : 11100000 00000000 00000000 00000000)
        //      - add length : as length maximal vlaue is 28 bits to 1, this does not modify the 4 most significance bits (1110)
        //      - end
        //      => minimal encoded value is 11100000 00100000 00000000 00000000
        // - length <= 0x7FFFFFFFFF (binary : 00000111 11111111 11111111 11111111 11111111 => 35 bits set to 1)
        //      - encode length with five bytes
        //      - set length value to 0xF000000000 (binary : 11110000 00000000 00000000 00000000 00000000)
        //      - add length : as length maximal vlaue is 35 bits to 1, this does not modify the 5 most significance bits (11110)
        //      - end
        // - length > 0x7FFFFFFFFF : not supported

        if ($length < 0) {
            throw new \DomainException("Length of word can not be negative ($length)");
        }

        if ($length <= 0x7F) {
            return BinaryStringHelper::IntegerToNBOBinaryString($length);
        }

        if ($length <= 0x3FFF) {
            return BinaryStringHelper::IntegerToNBOBinaryString(0x8000 + $length);
        }

        if ($length <= 0x1FFFFF) {
            return BinaryStringHelper::IntegerToNBOBinaryString(0xC00000 + $length);
        }

        if ($length <= 0x0FFFFFFF) {
            return BinaryStringHelper::IntegerToNBOBinaryString(0xE0000000 + $length);
        } // cannot compare with 0x7FFFFFFFFF on 32 bits systems

        if (PHP_INT_SIZE < 8) {
            // Cannot be done on 32 bits systems
            // PHP5 windows versions of php, even on 64 bits systems was impacted
            // see : https://stackoverflow.com/questions/27865340/php-int-size-returns-4-but-my-operating-system-is-64-bit

            // @codeCoverageIgnoreStart
            throw new \OverflowException("Your system is using 32 bits integers, cannot encode length of $length bytes on this system");
            // @codeCoverageIgnoreEnd
        }

        if ($length <= 0x7FFFFFFFFF) {
            return BinaryStringHelper::IntegerToNBOBinaryString(0xF000000000 + $length);
        }

        throw new \DomainException("Length of word too huge ($length)");
    }

    // Decode length of data when reading :
    // The 5 firsts bits of the first byte specify how the length is encoded.
    // The position of the first 0 value bit, starting from the most significant postion. 
    // - 0xxxxxxx => The 7 remainings bits of the first byte is the length : 
    //            => min value of length is 0x00 
    //            => max value of length is 0x7F (127 bytes)
    // - 10xxxxxx => The 6 remainings bits of the first byte plus the next byte represent the lenght
    //            NOTE : the next byte MUST be at least 0x80 !!
    //            => min value of length is 0x80 
    //            => max value of length is 0x3FFF (16,383 bytes, near 16 KB)
    // - 110xxxxx => The 5 remainings bits of th first byte and the two next bytes represent the length
    //             => max value of length is 0x1FFFFF (2,097,151 bytes, near 2 MB)
    // - 1110xxxx => The 4 remainings bits of the first byte and the three next bytes represent the length
    //            => max value of length is 0xFFFFFFF (268,435,455 bytes, near 270 MB)
    // - 11110xxx => The 3 remainings bits of the first byte and the four next bytes represent the length
    //            => max value of length is 0x7FFFFFFF (2,147,483,647 byes, 2GB)
    // - 11111xxx => This byte is not a length-encoded word but a control byte.
    //          =>  Extracted from Mikrotik API doc : 
    //              it is a reserved control byte. 
    //              After receiving unknown control byte API client cannot proceed, because it cannot know how to interpret following bytes
    //              Currently control bytes are not used

    public static function decodeLength(StreamInterface $stream): int
    {
        // if (false === is_resource($stream)) {
        //     throw new \InvalidArgumentException(
        //         sprintf(
        //             'Argument must be a stream resource type. %s given.',
        //             gettype($stream)
        //         )
        //     );
        // }

        // Read first byte
        $firstByte = ord($stream->read(1));

        // If first byte is not set, length is the value of the byte
        if (0 === ($firstByte & 0x80)) {
            return $firstByte;
        }

        // if 10xxxxxx, length is 2 bytes encoded
        if (0x80 === ($firstByte & 0xC0)) {
            // Set 2 most significands bits to 0
            $result = $firstByte & 0x3F;

            // shift left 8 bits to have 2 bytes
            $result <<= 8;

            // read next byte and use it as least significant
            $result |= ord($stream->read(1));
            return $result;
        }

        // if 110xxxxx, length is 3 bytes encoded
        if (0xC0 === ($firstByte & 0xE0)) {
            // Set 3 most significands bits to 0
            $result = $firstByte & 0x1F;

            // shift left 16 bits to have 3 bytes
            $result <<= 16;

            // read next 2 bytes as value and use it as least significant position
            $result |= (ord($stream->read(1)) << 8);
            $result |= ord($stream->read(1));
            return $result;
        }

        // if 1110xxxx, length is 4 bytes encoded
        if (0xE0 === ($firstByte & 0xF0)) {
            // Set 4 most significance bits to 0
            $result = $firstByte & 0x0F;

            // shift left 24 bits to have 4 bytes
            $result <<= 24;

            // read next 3 bytes as value and use it as least significant position
            $result |= (ord($stream->read(1)) << 16);
            $result |= (ord($stream->read(1)) << 8);
            $result |= ord($stream->read(1));
            return $result;
        }

        // if 11110xxx, length is 5 bytes encoded
        if (0xF0 === ($firstByte & 0xF8)) {
            // Not possible on 32 bits systems
            if (PHP_INT_SIZE < 8) {
                // Cannot be done on 32 bits systems
                // PHP5 windows versions of php, even on 64 bits systems was impacted
                // see : https://stackoverflow.com/questions/27865340/php-int-size-returns-4-but-my-operating-system-is-64-bit 
                // How can we test it ?
                // @codeCoverageIgnoreStart
                throw new \OverflowException("Your system is using 32 bits integers, cannot decode this value ($firstByte) on this system");
                // @codeCoverageIgnoreEnd
            }

            // Set 5 most significance bits to 0
            $result = $firstByte & 0x07;

            // shift left 232 bits to have 5 bytes
            $result <<= 32;

            // read next 4 bytes as value and use it as least significant position
            $result |= (ord($stream->read(1)) << 24);
            $result |= (ord($stream->read(1)) << 16);
            $result |= (ord($stream->read(1)) << 8);
            $result |= ord($stream->read(1));
            return $result;
        }

        // Now the only solution is 5 most significance bits are set to 1 (11111xxx)
        // This is a control word, not implemented by Mikrotik for the moment 
        throw new \UnexpectedValueException('Control Word found');
    }
}


1		<?php
2
3		namespace RouterOS;
4
5		use RouterOS\Interfaces\StreamInterface;
6		use RouterOS\Helpers\BinaryStringHelper;
7
8		/**
9		* class APILengthCoDec
10		*
11		* Coder / Decoder for length field in mikrotik API communication protocol
12		*
13		* @package RouterOS
14		* @since 0.9
15		*/
16		class APILengthCoDec
17		{
18	31	public static function encodeLength(int $length): string
19		{
20		// Encode the length :
21		// - if length <= 0x7F (binary : 01111111 => 7 bits set to 1)
22		// - encode length with one byte
23		// - set the byte to length value, as length maximal value is 7 bits set to 1, the most significant bit is always 0
24		// - end
25		// - length <= 0x3FFF (binary : 00111111 11111111 => 14 bits set to 1)
26		// - encode length with two bytes
27		// - set length value to 0x8000 (=> 10000000 00000000)
28		// - add length : as length maximumal value is 14 bits to 1, this does not modify the 2 most significance bits (10)
29		// - end
30		// => minimal encoded value is 10000000 10000000
31		// - length <= 0x1FFFFF (binary : 00011111 11111111 11111111 => 21 bits set to 1)
32		// - encode length with three bytes
33		// - set length value to 0xC00000 (binary : 11000000 00000000 00000000)
34		// - add length : as length maximal vlaue is 21 bits to 1, this does not modify the 3 most significance bits (110)
35		// - end
36		// => minimal encoded value is 11000000 01000000 00000000
37		// - length <= 0x0FFFFFFF (binary : 00001111 11111111 11111111 11111111 => 28 bits set to 1)
38		// - encode length with four bytes
39		// - set length value to 0xE0000000 (binary : 11100000 00000000 00000000 00000000)
40		// - add length : as length maximal vlaue is 28 bits to 1, this does not modify the 4 most significance bits (1110)
41		// - end
42		// => minimal encoded value is 11100000 00100000 00000000 00000000
43		// - length <= 0x7FFFFFFFFF (binary : 00000111 11111111 11111111 11111111 11111111 => 35 bits set to 1)
44		// - encode length with five bytes
45		// - set length value to 0xF000000000 (binary : 11110000 00000000 00000000 00000000 00000000)
46		// - add length : as length maximal vlaue is 35 bits to 1, this does not modify the 5 most significance bits (11110)
47		// - end
48		// - length > 0x7FFFFFFFFF : not supported
49
50	31	if ($length < 0) {
51	2	throw new \DomainException("Length of word can not be negative ($length)");
52		}
53
54	29	if ($length <= 0x7F) {
55	15	return BinaryStringHelper::IntegerToNBOBinaryString($length);
56		}
57
58	14	if ($length <= 0x3FFF) {
59	3	return BinaryStringHelper::IntegerToNBOBinaryString(0x8000 + $length);
60		}
61
62	11	if ($length <= 0x1FFFFF) {
63	3	return BinaryStringHelper::IntegerToNBOBinaryString(0xC00000 + $length);
64		}
65
66	8	if ($length <= 0x0FFFFFFF) {
67	3	return BinaryStringHelper::IntegerToNBOBinaryString(0xE0000000 + $length);
68		} // cannot compare with 0x7FFFFFFFFF on 32 bits systems
69
70	5	if (PHP_INT_SIZE < 8) {
71		// Cannot be done on 32 bits systems
72		// PHP5 windows versions of php, even on 64 bits systems was impacted
73		// see : https://stackoverflow.com/questions/27865340/php-int-size-returns-4-but-my-operating-system-is-64-bit
74
75		// @codeCoverageIgnoreStart
76		throw new \OverflowException("Your system is using 32 bits integers, cannot encode length of $length bytes on this system");
77		// @codeCoverageIgnoreEnd
78		}
79
80	5	if ($length <= 0x7FFFFFFFFF) {
81	3	return BinaryStringHelper::IntegerToNBOBinaryString(0xF000000000 + $length);
82		}
83
84	2	throw new \DomainException("Length of word too huge ($length)");
85		}
86
87		// Decode length of data when reading :
88		// The 5 firsts bits of the first byte specify how the length is encoded.
89		// The position of the first 0 value bit, starting from the most significant postion.
90		// - 0xxxxxxx => The 7 remainings bits of the first byte is the length :
91		// => min value of length is 0x00
92		// => max value of length is 0x7F (127 bytes)
93		// - 10xxxxxx => The 6 remainings bits of the first byte plus the next byte represent the lenght
94		// NOTE : the next byte MUST be at least 0x80 !!
95		// => min value of length is 0x80
96		// => max value of length is 0x3FFF (16,383 bytes, near 16 KB)
97		// - 110xxxxx => The 5 remainings bits of th first byte and the two next bytes represent the length
98		// => max value of length is 0x1FFFFF (2,097,151 bytes, near 2 MB)
99		// - 1110xxxx => The 4 remainings bits of the first byte and the three next bytes represent the length
100		// => max value of length is 0xFFFFFFF (268,435,455 bytes, near 270 MB)
101		// - 11110xxx => The 3 remainings bits of the first byte and the four next bytes represent the length
102		// => max value of length is 0x7FFFFFFF (2,147,483,647 byes, 2GB)
103		// - 11111xxx => This byte is not a length-encoded word but a control byte.
104		// => Extracted from Mikrotik API doc :
105		// it is a reserved control byte.
106		// After receiving unknown control byte API client cannot proceed, because it cannot know how to interpret following bytes
107		// Currently control bytes are not used
108
109	30	public static function decodeLength(StreamInterface $stream): int
110		{
111		// if (false === is_resource($stream)) {
112		// throw new \InvalidArgumentException(
113		// sprintf(
114		// 'Argument must be a stream resource type. %s given.',
115		// gettype($stream)
116		// )
117		// );
118		// }
119
120		// Read first byte
121	30	$firstByte = ord($stream->read(1));
122
123		// If first byte is not set, length is the value of the byte
124	30	if (0 === ($firstByte & 0x80)) {
125	15	return $firstByte;
126		}
127
128		// if 10xxxxxx, length is 2 bytes encoded
129	15	if (0x80 === ($firstByte & 0xC0)) {
130		// Set 2 most significands bits to 0
131	3	$result = $firstByte & 0x3F;
132
133		// shift left 8 bits to have 2 bytes
134	3	$result <<= 8;
135
136		// read next byte and use it as least significant
137	3	$result \|= ord($stream->read(1));
138	3	return $result;
139		}
140
141		// if 110xxxxx, length is 3 bytes encoded
142	12	if (0xC0 === ($firstByte & 0xE0)) {
143		// Set 3 most significands bits to 0
144	3	$result = $firstByte & 0x1F;
145
146		// shift left 16 bits to have 3 bytes
147	3	$result <<= 16;
148
149		// read next 2 bytes as value and use it as least significant position
150	3	$result \|= (ord($stream->read(1)) << 8);
151	3	$result \|= ord($stream->read(1));
152	3	return $result;
153		}
154
155		// if 1110xxxx, length is 4 bytes encoded
156	9	if (0xE0 === ($firstByte & 0xF0)) {
157		// Set 4 most significance bits to 0
158	3	$result = $firstByte & 0x0F;
159
160		// shift left 24 bits to have 4 bytes
161	3	$result <<= 24;
162
163		// read next 3 bytes as value and use it as least significant position
164	3	$result \|= (ord($stream->read(1)) << 16);
165	3	$result \|= (ord($stream->read(1)) << 8);
166	3	$result \|= ord($stream->read(1));
167	3	return $result;
168		}
169
170		// if 11110xxx, length is 5 bytes encoded
171	6	if (0xF0 === ($firstByte & 0xF8)) {
172		// Not possible on 32 bits systems
173	3	if (PHP_INT_SIZE < 8) {
174		// Cannot be done on 32 bits systems
175		// PHP5 windows versions of php, even on 64 bits systems was impacted
176		// see : https://stackoverflow.com/questions/27865340/php-int-size-returns-4-but-my-operating-system-is-64-bit
177		// How can we test it ?
178		// @codeCoverageIgnoreStart
179		throw new \OverflowException("Your system is using 32 bits integers, cannot decode this value ($firstByte) on this system");
180		// @codeCoverageIgnoreEnd
181		}
182
183		// Set 5 most significance bits to 0
184	3	$result = $firstByte & 0x07;
185
186		// shift left 232 bits to have 5 bytes
187	3	$result <<= 32;
188
189		// read next 4 bytes as value and use it as least significant position
190	3	$result \|= (ord($stream->read(1)) << 24);
191	3	$result \|= (ord($stream->read(1)) << 16);
192	3	$result \|= (ord($stream->read(1)) << 8);
193	3	$result \|= ord($stream->read(1));
194	3	return $result;
195		}
196
197		// Now the only solution is 5 most significance bits are set to 1 (11111xxx)
198		// This is a control word, not implemented by Mikrotik for the moment
199	3	throw new \UnexpectedValueException('Control Word found');
200		}
201		}
202

EvilFreelancer / routeros-api-php

Pull Request — master (#8)

APILengthCoDec::decodeLength() B

Complexity

Size

Duplication

Code Coverage

Importance

How to fix Long Method

Long Method

Duplication Side-by-Side

Filter issues like