Cache::evaluateDependency() - Code Metrics - Inspection of "Refactoring CacheInterface and add early expiratio..." - yiisoft/cache - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#74)

by Alexander

created 2020-12-14 23:02 UTC

Cache::evaluateDependency() A

↳ Parent: Project

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

<?php

declare(strict_types=1);

namespace Yiisoft\Cache;

use DateInterval;
use DateTime;
use Yiisoft\Cache\Dependency\Dependency;
use Yiisoft\Cache\Exception\InvalidArgumentException;
use Yiisoft\Cache\Exception\RemoveCacheException;
use Yiisoft\Cache\Exception\SetCacheException;
use Yiisoft\Cache\Metadata\CacheItem;
use Yiisoft\Cache\Metadata\CacheItems;

use function ctype_alnum;
use function gettype;
use function is_int;
use function is_string;
use function json_encode;
use function json_last_error_msg;
use function mb_strlen;
use function md5;

/**
 * Cache provides support for the data caching, including cache key composition and dependencies, and uses
 * "Probably early expiration" for cache stampede prevention. The actual data caching is performed via
 * {@see Cache::$handler}, which should be configured to be {@see \Psr\SimpleCache\CacheInterface} instance.
 *
 * @see \Yiisoft\Cache\CacheInterface
 */
final class Cache implements CacheInterface
{
    /**
     * @var \Psr\SimpleCache\CacheInterface The actual cache handler.
     */
    private \Psr\SimpleCache\CacheInterface $handler;

    /**
     * @var CacheItems The items that store the metadata of each cache.
     */
    private CacheItems $items;

    /**
     * @var int|null The default TTL for a cache entry. null meaning infinity, negative or zero results in the
     * cache key deletion. This value is used by {@see getOrSet()}, if the duration is not explicitly given.
     */
    private ?int $defaultTtl;

    /**
     * @var string The string prefixed to every cache key so that it is unique globally in the whole cache storage.
     * It is recommended that you set a unique cache key prefix for each application if the same cache
     * storage is being used by different applications.
     */
    private string $keyPrefix;

    /**
     * @param \Psr\SimpleCache\CacheInterface $handler The actual cache handler.
     * @param DateInterval|int|null $defaultTtl The default TTL for a cache entry. null meaning infinity, negative or zero results in the
     * cache key deletion. This value is used by {@see getOrSet()}, if the duration is not explicitly given.
     * @param string $keyPrefix The string prefixed to every cache key so that it is unique globally in the whole cache storage.
     * It is recommended that you set a unique cache key prefix for each application if the same cache
     * storage is being used by different applications.
     */
    public function __construct(\Psr\SimpleCache\CacheInterface $handler, $defaultTtl = null, string $keyPrefix = '')
    {
        $this->handler = $handler;
        $this->items = new CacheItems();
        $this->defaultTtl = $this->normalizeTtl($defaultTtl);
        $this->keyPrefix = $keyPrefix;
    }

    public function getOrSet($key, callable $callable, $ttl = null, Dependency $dependency = null, float $beta = 1.0)
    {
        $key = $this->buildKey($key);
        $value = $this->getValue($key, $beta);

        return $value ?? $this->setAndGet($key, $callable, $ttl, $dependency);
    }

    public function remove($key): void
    {
        $key = $this->buildKey($key);

        if (!$this->handler->delete($key)) {
            throw new RemoveCacheException($key);
        }

        $this->items->remove($key);
    }

    /**
     * Gets the cache value.
     *
     * @param string $key The unique key of this item in the cache.
     * @param float $beta The value for calculating the range that is used for "Probably early expiration" algorithm.
     *
     * @return mixed|null The cache value or `null` if the cache is outdated or a dependency has been changed.
     */
    private function getValue(string $key, float $beta)
    {
        if ($this->items->has($key)) {
            return $this->items->getValue($key, $beta, $this->handler);
        }

        $value = $this->handler->get($key);

        if ($value instanceof CacheItem) {
            $this->items->set($value);
            return $this->items->getValue($key, $beta, $this->handler);
        }

        return $value;
    }

    /**
     * Sets the cache value and metadata, and returns the cache value.
     *
     * @param string $key The unique key of this item in the cache.
     * @param callable $callable The callable or closure that will be used to generate a value to be cached.
     * @param DateInterval|int|null $ttl The TTL of this value. If not set, default value is used.
     * @param Dependency|null $dependency The dependency of the cache value.
     *
     * @throws InvalidArgumentException Must be thrown if the `$key` or `$ttl` is not a legal value.
     * @throws SetCacheException Must be thrown if the data could not be set in the cache.
     *
     * @return mixed|null The cache value.
     */
    private function setAndGet(string $key, callable $callable, $ttl, ?Dependency $dependency)
    {
        $ttl = $this->normalizeTtl($ttl);
        $ttl ??= $this->defaultTtl;
        $value = $callable($this->handler);

        if ($dependency !== null) {
            $dependency->evaluateDependency($this->handler);
        }

        $item = new CacheItem($key, $value, $ttl, $dependency);

        if (!$this->handler->set($key, $item, $ttl)) {
            throw new SetCacheException($key, $item);
        }

        $this->items->set($item);
        return $value;
    }

    /**
     * Builds a normalized cache key from a given key by appending key prefix.
     *
     * @param mixed $key The key to be normalized.
     *
     * @return string The generated cache key.
     */
    private function buildKey($key): string
    {
        return $this->keyPrefix . $this->normalizeKey($key);
    }

    /**
     * Normalizes the cache key from a given key.
     *
     * If the given key is a string containing alphanumeric characters only and no more than 32 characters,
     * then the key will be returned back as it is, integers will be converted to strings. Otherwise,
     * a normalized key is generated by serializing the given key and applying MD5 hashing.
     *
     * @param mixed $key The key to be normalized.
     *
     * @throws InvalidArgumentException For invalid key.
     *
     * @return string The normalized cache key.
     */
    private function normalizeKey($key): string
    {
        if (is_string($key) || is_int($key)) {
            $key = (string) $key;
            return ctype_alnum($key) && mb_strlen($key, '8bit') <= 32 ? $key : md5($key);
        }

        if (($key = json_encode($key)) === false) {
            throw new InvalidArgumentException('Invalid key. ' . json_last_error_msg());
        }

        return md5($key);
    }

    /**
     * Normalizes cache TTL handling `null` value and {@see DateInterval} objects.
     *
     * @param mixed $ttl raw TTL.
     *
     * @throws InvalidArgumentException For invalid TTL.
     *
     * @return int|null TTL value as UNIX timestamp or null meaning infinity.
     */
    private function normalizeTtl($ttl): ?int
    {
        if ($ttl === null) {
            return null;
        }

        if ($ttl instanceof DateInterval) {
            return (new DateTime('@0'))->add($ttl)->getTimestamp();
        }

        if (is_int($ttl)) {
            return $ttl;
        }

        throw new InvalidArgumentException(sprintf(
            'Invalid TTL "%s" specified. It must be a \DateInterval instance, an integer, or null.',
            gettype($ttl),
        ));
    }
}


1		<?php
2
3		declare(strict_types=1);
4
5		namespace Yiisoft\Cache;
6
7		use DateInterval;
8		use DateTime;
9		use Yiisoft\Cache\Dependency\Dependency;
10		use Yiisoft\Cache\Exception\InvalidArgumentException;
11		use Yiisoft\Cache\Exception\RemoveCacheException;
12		use Yiisoft\Cache\Exception\SetCacheException;
13		use Yiisoft\Cache\Metadata\CacheItem;
14		use Yiisoft\Cache\Metadata\CacheItems;
15
16		use function ctype_alnum;
17		use function gettype;
18		use function is_int;
19		use function is_string;
20		use function json_encode;
21		use function json_last_error_msg;
22		use function mb_strlen;
23		use function md5;
24
25		/**
26		* Cache provides support for the data caching, including cache key composition and dependencies, and uses
27		* "Probably early expiration" for cache stampede prevention. The actual data caching is performed via
28		* {@see Cache::$handler}, which should be configured to be {@see \Psr\SimpleCache\CacheInterface} instance.
29		*
30		* @see \Yiisoft\Cache\CacheInterface
31		*/
32		final class Cache implements CacheInterface
33		{
34		/**
35		* @var \Psr\SimpleCache\CacheInterface The actual cache handler.
36		*/
37		private \Psr\SimpleCache\CacheInterface $handler;
38
39		/**
40		* @var CacheItems The items that store the metadata of each cache.
41		*/
42		private CacheItems $items;
43
44		/**
45		* @var int\|null The default TTL for a cache entry. null meaning infinity, negative or zero results in the
46		* cache key deletion. This value is used by {@see getOrSet()}, if the duration is not explicitly given.
47		*/
48		private ?int $defaultTtl;
49
50		/**
51		* @var string The string prefixed to every cache key so that it is unique globally in the whole cache storage.
52		* It is recommended that you set a unique cache key prefix for each application if the same cache
53		* storage is being used by different applications.
54		*/
55		private string $keyPrefix;
56
57		/**
58		* @param \Psr\SimpleCache\CacheInterface $handler The actual cache handler.
59		* @param DateInterval\|int\|null $defaultTtl The default TTL for a cache entry. null meaning infinity, negative or zero results in the
60		* cache key deletion. This value is used by {@see getOrSet()}, if the duration is not explicitly given.
61		* @param string $keyPrefix The string prefixed to every cache key so that it is unique globally in the whole cache storage.
62		* It is recommended that you set a unique cache key prefix for each application if the same cache
63		* storage is being used by different applications.
64		*/
65	57	public function __construct(\Psr\SimpleCache\CacheInterface $handler, $defaultTtl = null, string $keyPrefix = '')
66		{
67	57	$this->handler = $handler;
68	57	$this->items = new CacheItems();
69	57	$this->defaultTtl = $this->normalizeTtl($defaultTtl);
70	51	$this->keyPrefix = $keyPrefix;
71	51	}
72
73	48	public function getOrSet($key, callable $callable, $ttl = null, Dependency $dependency = null, float $beta = 1.0)
74		{
75	48	$key = $this->buildKey($key);
76	47	$value = $this->getValue($key, $beta);
77
78	47	return $value ?? $this->setAndGet($key, $callable, $ttl, $dependency);
79		}
80
81	15	public function remove($key): void
82		{
83	15	$key = $this->buildKey($key);
84
85	14	if (!$this->handler->delete($key)) {
86	2	throw new RemoveCacheException($key);
87		}
88
89	12	$this->items->remove($key);
90	12	}
91
92		/**
93		* Gets the cache value.
94		*
95		* @param string $key The unique key of this item in the cache.
96		* @param float $beta The value for calculating the range that is used for "Probably early expiration" algorithm.
97		*
98		* @return mixed\|null The cache value or `null` if the cache is outdated or a dependency has been changed.
99		*/
100	47	private function getValue(string $key, float $beta)
101		{
102	47	if ($this->items->has($key)) {
103	5	return $this->items->getValue($key, $beta, $this->handler);
104		}
105
106	47	$value = $this->handler->get($key);
107
108	47	if ($value instanceof CacheItem) {
109		$this->items->set($value);
110		return $this->items->getValue($key, $beta, $this->handler);
111		}
112
113	47	return $value;
114		}
115
116		/**
117		* Sets the cache value and metadata, and returns the cache value.
118		*
119		* @param string $key The unique key of this item in the cache.
120		* @param callable $callable The callable or closure that will be used to generate a value to be cached.
121		* @param DateInterval\|int\|null $ttl The TTL of this value. If not set, default value is used.
122		* @param Dependency\|null $dependency The dependency of the cache value.
123		*
124		* @throws InvalidArgumentException Must be thrown if the `$key` or `$ttl` is not a legal value.
125		* @throws SetCacheException Must be thrown if the data could not be set in the cache.
126		*
127		* @return mixed\|null The cache value.
128		*/
129	47	private function setAndGet(string $key, callable $callable, $ttl, ?Dependency $dependency)
130		{
131	47	$ttl = $this->normalizeTtl($ttl);
132	41	$ttl ??= $this->defaultTtl;
133	41	$value = $callable($this->handler);
134
135	41	if ($dependency !== null) {
136	6	$dependency->evaluateDependency($this->handler);
137		}
138
139	41	$item = new CacheItem($key, $value, $ttl, $dependency);
140
141	41	if (!$this->handler->set($key, $item, $ttl)) {
142	2	throw new SetCacheException($key, $item);
143		}
144
145	39	$this->items->set($item);
146	39	return $value;
147		}
148
149		/**
150		* Builds a normalized cache key from a given key by appending key prefix.
151		*
152		* @param mixed $key The key to be normalized.
153		*
154		* @return string The generated cache key.
155		*/
156	51	private function buildKey($key): string
157		{
158	51	return $this->keyPrefix . $this->normalizeKey($key);
159		}
160
161		/**
162		* Normalizes the cache key from a given key.
163		*
164		* If the given key is a string containing alphanumeric characters only and no more than 32 characters,
165		* then the key will be returned back as it is, integers will be converted to strings. Otherwise,
166		* a normalized key is generated by serializing the given key and applying MD5 hashing.
167		*
168		* @param mixed $key The key to be normalized.
169		*
170		* @throws InvalidArgumentException For invalid key.
171		*
172		* @return string The normalized cache key.
173		*/
174	51	private function normalizeKey($key): string
175		{
176	51	if (is_string($key) \|\| is_int($key)) {
177	33	$key = (string) $key;
178	33	return ctype_alnum($key) && mb_strlen($key, '8bit') <= 32 ? $key : md5($key);
179		}
180
181	18	if (($key = json_encode($key)) === false) {
182	2	throw new InvalidArgumentException('Invalid key. ' . json_last_error_msg());
183		}
184
185	16	return md5($key);
186		}
187
188		/**
189		* Normalizes cache TTL handling `null` value and {@see DateInterval} objects.
190		*
191		* @param mixed $ttl raw TTL.
192		*
193		* @throws InvalidArgumentException For invalid TTL.
194		*
195		* @return int\|null TTL value as UNIX timestamp or null meaning infinity.
196		*/
197	57	private function normalizeTtl($ttl): ?int
198		{
199	57	if ($ttl === null) {
200	51	return null;
201		}
202
203	19	if ($ttl instanceof DateInterval) {
204	2	return (new DateTime('@0'))->add($ttl)->getTimestamp();
205		}
206
207	17	if (is_int($ttl)) {
208	5	return $ttl;
209		}
210
211	12	throw new InvalidArgumentException(sprintf(
212	12	'Invalid TTL "%s" specified. It must be a \DateInterval instance, an integer, or null.',
213	12	gettype($ttl),
214		));
215		}
216		}
217

yiisoft / cache

Pull Request — master (#74)

Cache::evaluateDependency() A

Complexity

Size

Duplication

Code Coverage

Importance

Duplication Side-by-Side

Filter issues like