RangeSet::createFromHeader() - Code Metrics - DaveRandom/Resume - Measure and Improve Code Quality continuously with Scrutinizer

RangeSet::createFromHeader() A
last analyzed 2018-06-25 10:22 UTC

↳ Parent: RangeSet

Complexity

Conditions	4
Paths	4

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	10
CRAP Score	4

Importance

Changes

Metric	Value
cc	4
nc	4
nop	2
dl	0
loc	18
ccs	10
cts	10
cp	1
crap	4
rs	9.6666
c	0
b	0
f	0

<?php declare(strict_types=1);

namespace DaveRandom\Resume;

final class RangeSet
{
    const DEFAULT_MAX_RANGES = 10;

    /** @internal */
    const HEADER_PARSE_EXPR = /** @lang regex */ '/
      ^
      \s*                 # tolerate lead white-space
      (?<unit> [^\s=]+ )  # unit is everything up to first = or white-space
      (?: \s*=\s* | \s+ ) # separator is = or white-space
      (?<ranges> .+ )     # remainder is range spec
    /x';

    /** @internal */
    const RANGE_PARSE_EXPR = /** @lang regex */ '/
      ^
      (?<start> [0-9]* ) # start is a decimal number
      \s*-\s*            # separator is a dash
      (?<end> [0-9]* )   # end is a decimal number
      $
    /x';

    /**
     * The unit for ranges in the set
     *
     * @var string
     */
    private $unit;

    /**
     * The ranges in the set
     *
     * @var Range[]
     */
    private $ranges = [];

    /**
     * Parse an array of range specifiers into an array of Range objects
     *
     * @param string[] $ranges
     * @return Range[]
     */
    private static function parseRanges(array $ranges): array
    {
        $result = [];

        foreach ($ranges as $i => $range) {
            if (!\preg_match(self::RANGE_PARSE_EXPR, \trim($range), $match)) {
                throw new InvalidRangeHeaderException("Invalid range format at position {$i}: Parse failure");
            }

            if ($match['start'] === '' && $match['end'] === '') {
                throw new InvalidRangeHeaderException("Invalid range format at position {$i}: Start and end empty");
            }

            $result[] = $match['start'] === ''
                ? new Range(((int)$match['end']) * -1)
                : new Range((int)$match['start'], $match['end'] !== '' ? (int)$match['end'] : null);
        }

        return $result;
    }

    /**
     * Get a set of normalized ranges applied to a resource size
     *
     * @param int $size
     * @return Range[]
     */
    private function normalizeRangesForSize(int $size): array
    {
        $result = [];

        foreach ($this->ranges as $range) {
            try {
                $range = $range->normalize($size);

                if ($range->getStart() < $size) {
                    $result[] = $range;
                }
            } catch (UnsatisfiableRangeException $e) {
                // ignore, other ranges in the set may be satisfiable
            }
        }

        if (empty($result)) {
            throw new UnsatisfiableRangeException('No specified ranges are satisfiable by a resource of the specified size');
        }

        return $result;
    }

    /**
     * Combine overlapping ranges in the supplied array and return the result
     *
     * @param Range[] $ranges
     * @return Range[]
     */
    private function combineOverlappingRanges(array $ranges)
    {
        \usort($ranges, static function(Range $a, Range $b) {
            return $a->getStart() <=> $b->getStart();
        });

        for ($i = 0, $l = \count($ranges) - 1; $i < $l; $i++) {
            if (!$ranges[$i]->overlaps($ranges[$i + 1])) {
                continue;
            }

            $ranges[$i] = $ranges[$i]->combine($ranges[$i + 1]);
            unset($ranges[$i + 1]);

            $i++;
        }

        return $ranges;
    }

    /**
     * Create a new instance from a Range header string
     *
     * @param string|null $header
     * @param int $maxRanges
     * @return self|null
     */
    public static function createFromHeader(string $header = null, int $maxRanges = self::DEFAULT_MAX_RANGES)
    {
        if ($header === null) {
            return null;
        }

        if (!\preg_match(self::HEADER_PARSE_EXPR, $header, $match)) {
            throw new InvalidRangeHeaderException('Invalid header: Parse failure');
        }

        $unit = $match['unit'];
        $ranges = \explode(',', $match['ranges']);

        if (\count($ranges) > $maxRanges) {
            throw new InvalidRangeHeaderException("Invalid header: Too many ranges");
        }

        return new self($unit, self::parseRanges($ranges));
    }

    /**
     * @param string $unit
     * @param Range[] $ranges
     */
    public function __construct(string $unit, array $ranges)
    {
        $this->unit = $unit;
        $this->ranges = $ranges;
    }

    /**
     * Get the unit for ranges in the set
     *
     * @return string
     */
    public function getUnit(): string
    {
        return $this->unit;
    }

    /**
     * Get a set of normalized ranges applied to a resource size, reduced to the minimum set of ranges
     *
     * @param int $size
     * @return Range[]
     */
    public function getRangesForSize(int $size): array
    {
        $ranges = $this->normalizeRangesForSize($size);

        $previousCount = null;
        $count = \count($ranges);

        while ($count > 1 && $count !== $previousCount) {
            $previousCount = $count;

            $ranges = $this->combineOverlappingRanges($ranges);

            $count = \count($ranges);
        }

        return $ranges;
    }
}


1		<?php declare(strict_types=1);
2
3		namespace DaveRandom\Resume;
4
5		final class RangeSet
6		{
7		const DEFAULT_MAX_RANGES = 10;
8
9		/** @internal */
10		const HEADER_PARSE_EXPR = /** @lang regex */ '/
11		^
12		\s* # tolerate lead white-space
13		(?<unit> [^\s=]+ ) # unit is everything up to first = or white-space
14		(?: \s=\s \| \s+ ) # separator is = or white-space
15		(?<ranges> .+ ) # remainder is range spec
16		/x';
17
18		/** @internal */
19		const RANGE_PARSE_EXPR = /** @lang regex */ '/
20		^
21		(?<start> [0-9]* ) # start is a decimal number
22		\s-\s # separator is a dash
23		(?<end> [0-9]* ) # end is a decimal number
24		$
25		/x';
26
27		/**
28		* The unit for ranges in the set
29		*
30		* @var string
31		*/
32		private $unit;
33
34		/**
35		* The ranges in the set
36		*
37		* @var Range[]
38		*/
39		private $ranges = [];
40
41		/**
42		* Parse an array of range specifiers into an array of Range objects
43		*
44		* @param string[] $ranges
45		* @return Range[]
46		*/
47	9	private static function parseRanges(array $ranges): array
48		{
49	9	$result = [];
50
51	9	foreach ($ranges as $i => $range) {
52	9	if (!\preg_match(self::RANGE_PARSE_EXPR, \trim($range), $match)) {
53	1	throw new InvalidRangeHeaderException("Invalid range format at position {$i}: Parse failure");
54		}
55
56	8	if ($match['start'] === '' && $match['end'] === '') {
57	1	throw new InvalidRangeHeaderException("Invalid range format at position {$i}: Start and end empty");
58		}
59
60	7	$result[] = $match['start'] === ''
61	1	? new Range(((int)$match['end']) * -1)
62	7	: new Range((int)$match['start'], $match['end'] !== '' ? (int)$match['end'] : null);
63		}
64
65	7	return $result;
66		}
67
68		/**
69		* Get a set of normalized ranges applied to a resource size
70		*
71		* @param int $size
72		* @return Range[]
73		*/
74	6	private function normalizeRangesForSize(int $size): array
75		{
76	6	$result = [];
77
78	6	foreach ($this->ranges as $range) {
79		try {
80	6	$range = $range->normalize($size);
81
82	5	if ($range->getStart() < $size) {
83	5	$result[] = $range;
84		}
85	6	} catch (UnsatisfiableRangeException $e) {
86		// ignore, other ranges in the set may be satisfiable
87		}
88		}
89
90	6	if (empty($result)) {
91	1	throw new UnsatisfiableRangeException('No specified ranges are satisfiable by a resource of the specified size');
92		}
93
94	5	return $result;
95		}
96
97		/**
98		* Combine overlapping ranges in the supplied array and return the result
99		*
100		* @param Range[] $ranges
101		* @return Range[]
102		*/
103		private function combineOverlappingRanges(array $ranges)
104		{
105	2	\usort($ranges, static function(Range $a, Range $b) {
106	2	return $a->getStart() <=> $b->getStart();
107	2	});
108
109	2	for ($i = 0, $l = \count($ranges) - 1; $i < $l; $i++) {
110	2	if (!$ranges[$i]->overlaps($ranges[$i + 1])) {
111	1	continue;
112		}
113
114	1	$ranges[$i] = $ranges[$i]->combine($ranges[$i + 1]);
115	1	unset($ranges[$i + 1]);
116
117	1	$i++;
118		}
119
120	2	return $ranges;
121		}
122
123		/**
124		* Create a new instance from a Range header string
125		*
126		* @param string\|null $header
127		* @param int $maxRanges
128		* @return self\|null
129		*/
130	11	public static function createFromHeader(string $header = null, int $maxRanges = self::DEFAULT_MAX_RANGES)
131		{
132	11	if ($header === null) {
133	1	return null;
134		}
135
136	10	if (!\preg_match(self::HEADER_PARSE_EXPR, $header, $match)) {
137	1	throw new InvalidRangeHeaderException('Invalid header: Parse failure');
138		}
139
140	9	$unit = $match['unit'];
141	9	$ranges = \explode(',', $match['ranges']);
142
143	9	if (\count($ranges) > $maxRanges) {
144	1	throw new InvalidRangeHeaderException("Invalid header: Too many ranges");
145		}
146
147	9	return new self($unit, self::parseRanges($ranges));
148		}
149
150		/**
151		* @param string $unit
152		* @param Range[] $ranges
153		*/
154	7	public function __construct(string $unit, array $ranges)
155		{
156	7	$this->unit = $unit;
157	7	$this->ranges = $ranges;
158		}
159
160		/**
161		* Get the unit for ranges in the set
162		*
163		* @return string
164		*/
165	5	public function getUnit(): string
166		{
167	5	return $this->unit;
168		}
169
170		/**
171		* Get a set of normalized ranges applied to a resource size, reduced to the minimum set of ranges
172		*
173		* @param int $size
174		* @return Range[]
175		*/
176	6	public function getRangesForSize(int $size): array
177		{
178	6	$ranges = $this->normalizeRangesForSize($size);
179
180	5	$previousCount = null;
181	5	$count = \count($ranges);
182
183	5	while ($count > 1 && $count !== $previousCount) {
184	2	$previousCount = $count;
185
186	2	$ranges = $this->combineOverlappingRanges($ranges);
187
188	2	$count = \count($ranges);
189		}
190
191	5	return $ranges;
192		}
193		}
194

DaveRandom / Resume

RangeSet::createFromHeader() A last analyzed 2018-06-25 10:22 UTC

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RangeSet::createFromHeader() A
last analyzed 2018-06-25 10:22 UTC