Passed
Push — master ( 5f4e36...3f9ee1 )
by Alexander
02:07
created

Cache::buildKey()   A

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