ProbabilitySelector::export() - Code Metrics - Inspection of "`export()` method added and tested." - Smoren/probability-selector-php - Measure and Improve Code Quality continuously with Scrutinizer

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by Smoren

created 2023-02-28 07:37 UTC

ProbabilitySelector::export() A

↳ Parent: ProbabilitySelector

Complexity

Conditions	1
Paths	1

Size

Total Lines	3
Code Lines	1

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes

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

<?php

declare(strict_types=1);

namespace Smoren\ProbabilitySelector;

/**
 * Probability-based selection manager.
 *
 * @template T
 *
 * @implements \IteratorAggregate<int, T>
 */
class ProbabilitySelector implements \IteratorAggregate
{
    /**
     * @var array<T> data storage
     */
    protected array $data = [];

    /**
     * @var array<array{float, int}>

     */
    protected array $probabilities = [];

    /**
     * @var float sum of all the weights of data
     */
    protected float $weightSum = 0;

    /**
     * @var int usage counters sum of data
     */
    protected int $totalUsageCounter = 0;

    /**
     * ProbabilitySelector constructor.
     *
     * @param array<array{T, float}|array{T, float, int}> $data

     */
    public function __construct(array $data = [])
    {
        foreach ($data as $item) {
            if (\count($item) === 2) {
                $item[] = 0;
            }

            /** @var array{T, float, int} $item */
            [$datum, $weight, $usageCounter] = $item;
            $this->addItem($datum, $weight, $usageCounter);
        }
    }

    /**
     * Adds datum to the select list.
     *
     * @param T $datum datum to add
     * @param float $weight weight of datum
     * @param int $usageCounter initial usage counter value for datum
     *
     * @return $this
     */
    public function addItem($datum, float $weight, int $usageCounter): self
    {
        if ($weight <= 0) {
            throw new \InvalidArgumentException('Weight cannot be negative');
        }

        $this->data[] = $datum;
        $this->probabilities[] = [$weight, $usageCounter];
        $this->weightSum += $weight;
        $this->totalUsageCounter += $usageCounter;

        return $this;
    }

    /**
     * Chooses and returns datum from select list, marks it used.
     *
     * @return T chosen datum
     *
     * @throws \LengthException when selectable list is empty
     */
    public function decide()
    {
        $maxScore = -INF;
        $maxScoreWeight = -INF;
        $maxScoreId = null;

        if (\count($this->probabilities) === 0) {
            throw new \LengthException('Candidate not found in empty list');
        }

        foreach ($this->probabilities as $id => [$weight, $usageCounter]) {
            $score = $weight / ($usageCounter + 1);

            if ($this->areFloatsEqual($score, $maxScore) && $weight > $maxScoreWeight || $score > $maxScore) {

                $maxScore = $score;
                $maxScoreWeight = $weight;
                $maxScoreId = $id;
            }
        }

        /** @var int $maxScoreId */
        $this->incrementUsageCounter($maxScoreId);
        return $this->data[$maxScoreId];
    }

    /**
     * Returns iterator to get decisions sequence.
     *
     * @param int|null $limit
     *
     * @return \Generator
     */
    public function getIterator(?int $limit = null): \Generator
    {
        for ($i = 0; $limit === null || $i < $limit; ++$i) {
            yield $this->totalUsageCounter => $this->decide();
        }
    }

    /**
     * Exports data with probabilities and usage counters.
     *
     * @return array<array{T, float, int}>

     */
    public function export(): array
    {
        return array_map(fn ($datum, $config) => [$datum, ...$config], $this->data, $this->probabilities);
    }

    /**
     * Increments usage counter of datum by its ID.
     *
     * @param int $id datum ID
     *
     * @return int current value of usage counter
     */
    protected function incrementUsageCounter(int $id): int
    {
        $this->totalUsageCounter++;
        return ++$this->probabilities[$id][1];
    }

    /**
     * Returns true if parameters are equal.
     *
     * @param float $lhs
     * @param float $rhs
     *
     * @return bool
     */
    protected function areFloatsEqual(float $lhs, float $rhs): bool
    {
        return \abs($lhs - $rhs) < PHP_FLOAT_EPSILON;
    }
}


1		<?php
2
3		declare(strict_types=1);
4
5		namespace Smoren\ProbabilitySelector;
6
7		/**
8		* Probability-based selection manager.
9		*
10		* @template T
11		*
12		* @implements \IteratorAggregate<int, T>
13		*/
14		class ProbabilitySelector implements \IteratorAggregate
15		{
16		/**
17		* @var array<T> data storage
18		*/
19		protected array $data = [];
20
21		/**
22		* @var array<array{float, int}>
		0 ignored issues – show Documentation Bug introduced 2023-02-27 08:57 UTC by Report Bug Copy Issue Report The doc comment `array<array{float, int}>` at position `4` could not be parsed: Expected ':' at position 4, but found 'float'. Loading history...
23		*/
24		protected array $probabilities = [];
25
26		/**
27		* @var float sum of all the weights of data
28		*/
29		protected float $weightSum = 0;
30
31		/**
32		* @var int usage counters sum of data
33		*/
34		protected int $totalUsageCounter = 0;
35
36		/**
37		* ProbabilitySelector constructor.
38		*
39		* @param array<array{T, float}\|array{T, float, int}> $data
		0 ignored issues – show Documentation Bug introduced 2023-02-27 13:58 UTC by Report Bug Copy Issue Report The doc comment `array<array{T, float}\|array{T, float, int}>` at position `4` could not be parsed: Expected ':' at position 4, but found 'T'. Loading history...
40		*/
41	47	public function __construct(array $data = [])
42		{
43	47	foreach ($data as $item) {
44	46	if (\count($item) === 2) {
45	41	$item[] = 0;
46		}
47
48		/** @var array{T, float, int} $item */
49	46	[$datum, $weight, $usageCounter] = $item;
50	46	$this->addItem($datum, $weight, $usageCounter);
51		}
52		}
53
54		/**
55		* Adds datum to the select list.
56		*
57		* @param T $datum datum to add
58		* @param float $weight weight of datum
59		* @param int $usageCounter initial usage counter value for datum
60		*
61		* @return $this
62		*/
63	46	public function addItem($datum, float $weight, int $usageCounter): self
64		{
65	46	if ($weight <= 0) {
66	4	throw new \InvalidArgumentException('Weight cannot be negative');
67		}
68
69	43	$this->data[] = $datum;
70	43	$this->probabilities[] = [$weight, $usageCounter];
71	43	$this->weightSum += $weight;
72	43	$this->totalUsageCounter += $usageCounter;
73
74	43	return $this;
75		}
76
77		/**
78		* Chooses and returns datum from select list, marks it used.
79		*
80		* @return T chosen datum
81		*
82		* @throws \LengthException when selectable list is empty
83		*/
84	43	public function decide()
85		{
86	43	$maxScore = -INF;
87	43	$maxScoreWeight = -INF;
88	43	$maxScoreId = null;
89
90	43	if (\count($this->probabilities) === 0) {
91	1	throw new \LengthException('Candidate not found in empty list');
92		}
93
94	42	foreach ($this->probabilities as $id => [$weight, $usageCounter]) {
95	42	$score = $weight / ($usageCounter + 1);
96
97	42	if ($this->areFloatsEqual($score, $maxScore) && $weight > $maxScoreWeight \|\| $score > $maxScore) {
		0 ignored issues – show introduced 2023-02-27 13:58 UTC by Report Bug Copy Issue Report Consider adding parentheses for clarity. Current Interpretation: `($this->areFloatsEqual($...) \|\| $score > $maxScore`, Probably Intended Meaning: `$this->areFloatsEqual($s... \|\| $score > $maxScore)` Loading history...
98	42	$maxScore = $score;
99	42	$maxScoreWeight = $weight;
100	42	$maxScoreId = $id;
101		}
102		}
103
104		/** @var int $maxScoreId */
105	42	$this->incrementUsageCounter($maxScoreId);
106	42	return $this->data[$maxScoreId];
107		}
108
109		/**
110		* Returns iterator to get decisions sequence.
111		*
112		* @param int\|null $limit
113		*
114		* @return \Generator
115		*/
116	32	public function getIterator(?int $limit = null): \Generator
117		{
118	32	for ($i = 0; $limit === null \|\| $i < $limit; ++$i) {
119	32	yield $this->totalUsageCounter => $this->decide();
120		}
121		}
122
123		/**
124		* Exports data with probabilities and usage counters.
125		*
126		* @return array<array{T, float, int}>
		0 ignored issues – show Documentation Bug introduced 2023-02-28 07:39 UTC by Report Bug Copy Issue Report The doc comment `array<array{T, float, int}>` at position `4` could not be parsed: Expected ':' at position 4, but found 'T'. Loading history...
127		*/
128	2	public function export(): array
129		{
130	2	return array_map(fn ($datum, $config) => [$datum, ...$config], $this->data, $this->probabilities);
131		}
132
133		/**
134		* Increments usage counter of datum by its ID.
135		*
136		* @param int $id datum ID
137		*
138		* @return int current value of usage counter
139		*/
140	42	protected function incrementUsageCounter(int $id): int
141		{
142	42	$this->totalUsageCounter++;
143	42	return ++$this->probabilities[$id][1];
144		}
145
146		/**
147		* Returns true if parameters are equal.
148		*
149		* @param float $lhs
150		* @param float $rhs
151		*
152		* @return bool
153		*/
154	42	protected function areFloatsEqual(float $lhs, float $rhs): bool
155		{
156	42	return \abs($lhs - $rhs) < PHP_FLOAT_EPSILON;
157		}
158		}
159

Smoren / probability-selector-php

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ProbabilitySelector::export() A

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