InMemoryCache::__construct() - Code Metrics - Inspection of "Adapt UserHandler to use InMemory cache" - ezsystems/ezpublish-kernel - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — in-memory-cache2 ( 0f2241...bf3815 )

by André

created 2019-03-06 06:02 UTC

InMemoryCache::__construct() A

↳ Parent: InMemoryCache

Complexity

Conditions	1
Paths	1

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
nc	1
nop	3
dl	0
loc	6
rs	10
c	0
b	0
f	0

<?php

/**
 * File containing MetadataCachePool class.
 *
 * @copyright Copyright (C) eZ Systems AS. All rights reserved.
 * @license For full copyright and license information view LICENSE file distributed with this source code.
 */
declare(strict_types=1);

namespace eZ\Publish\Core\Persistence\Cache\InMemory;

/**
 * Simple In-Memory Cache Pool.
 *
 * Could be used as separate instances for different use cases with a shared global expiry when applicable.
 *
 * Allow to use one instance with low ttl (200-600 milliseconds) and limited items (~100) dedicated to content (and
 * related classes) to handle burst caching, and a separate instance with longer ttl (3-10sec) and separate limit (~200)
 * for meta values like content type, section, ... to handle repeated lookups for these seldom changing values.
 *
 * @internal Only for use in eZ\Publish\Core\Persistence\Cache\AbstractInMemoryHandler, may change depending on needs there.
 */
class InMemoryCache
{
    /**
     * @var float Cache Time to Live, in seconds. This is only for how long we keep cache object around in-memory.
     */
    private $ttl;

    /**
     * @var int The limit of objects in cache pool at a given time
     */
    private $limit;

    /**
     * @var bool Switch for enabeling/disabling in-memory cache
     */
    private $enabled;

    /**
     * Cache objects by primary key.
     *
     * @var object[]
     */
    private $cache = [];

    /**
     * @var float[] Timestamp (float microtime) for individual cache by primary key.
     */
    private $cacheTime = [];

    /**
     * Mapping of secondary index to primary key.
     *
     * @var string[]
     */
    private $cacheIndex = [];

    /**
     * @var float|null Micro timestamp with time clear($global=true) has been called to synchronize across cache pools.
     */
    private $cacheExpiryTime;
    protected static $globalCacheExpiry;

    /**
     * Language Cache constructor.
     *
     * @param float $ttl Seconds for the cache to live as a float, by default 0.3 (300 milliseconds)
     * @param int $limit Limit for values to keep in cache, by default 100 cache values (per pool instance).
     * @param bool $enabled For use by configuration to be able to disable or enable depending on needs.
     */
    public function __construct(float $ttl = 0.3, int $limit = 100, bool $enabled = true)
    {
        $this->ttl = $ttl;
        $this->limit = $limit;
        $this->enabled = $enabled;
    }

    /**
     * Returns a cache objects.
     *
     * @param string $key Primary or secondary index to look for cache on.
     *
     * @return object|null Object if found, null if not.
     */
    public function get(string $key)
    {
        if ($this->enabled === false) {
            return null;
        }

        // Check for global expiry change, if the case clear cache
        if ($this->cacheExpiryTime !== self::$globalCacheExpiry) {
            $this->clear();
            $this->cacheExpiryTime = self::$globalCacheExpiry;

            return null;
        }

        $index = $this->cacheIndex[$key] ?? $key;
        if (!isset($this->cache[$index]) || $this->cacheTime[$index] + $this->ttl < microtime(true)) {
            return null;
        }

        return $this->cache[$index];
    }

    /**
     * Set object in in-memory cache.
     *
     * Should only set Cache hits here!
     *
     * @param object[] $objects
     * @param callable $objectIndexes Return array of indexes per object (first argument), must return at least 1 primary index
     * @param string|null $listIndex Optional index for list of items
     */
    public function setMulti(array $objects, callable $objectIndexes, string $listIndex = null): void
    {
        // If objects accounts for more then 20% of our limit, assume it's bulk content load and skip saving in-memory
        if ($this->enabled === false || \count($objects) >= $this->limit / 5) {
            return;
        }

        // check if we will reach limit by adding these objects, if so remove old cache
        if (\count($this->cache) + \count($objects) >= $this->limit) {
            $this->vacuum();
        }

        $time = microtime(true);

        // if set add objects to cache on list index (typically a "all" key)
        if ($listIndex) {
''   == false // true
''   == null  // true
'ab' == false // false
'ab' == null  // false

// It is often better to use strict comparison
'' === false // false
'' === null  // false
            $this->cache[$listIndex] = $objects;
            $this->cacheTime[$listIndex] = $time;
        }

        foreach ($objects as $object) {
            // Skip if there are no indexes
            if (!$indexes = $objectIndexes($object)) {
                continue;
            }

            $key = array_shift($indexes);
            $this->cache[$key] = $object;
            $this->cacheTime[$key] = $time;

            foreach ($indexes as $index) {
                $this->cacheIndex[$index] = $key;
            }
        }
    }

    /**
     * Removes multiple in-memory cache from the pool.
     *
     * @param string[] $keys An array of keys that should be removed from the pool.
     */
    public function deleteMulti(array $keys): void
    {
        if ($this->enabled === false) {
            return;
        }

        foreach ($keys as $key) {
            if ($index = $this->cacheIndex[$key] ?? null) {
                unset($this->cacheIndex[$key], $this->cache[$index], $this->cacheTime[$index]);
            } else {
                unset($this->cache[$key], $this->cacheTime[$key]);
            }
        }
    }

    /**
     * Deletes all cache in the in-memory pool.
     */
    public function clear(bool $global = false): void
    {
        // On purpose does not check if enabled, in case of several instances we allow clearing cache
        $this->cache = $this->cacheIndex = $this->cacheTime = [];
        if ($global) {
            $this->cacheExpiryTime = self::$globalCacheExpiry = microtime(true);
        }
    }

    /**
     * Call to reduce cache items when $limit has been reached.
     *
     * Deletes expired first, then oldest(or least used?).
     */
    private function vacuum(): void
    {
        // Vacuuming cache in bulk, clearing the 33% oldest cache values
        $this->cache = \array_slice($this->cache, \floor($this->limit / 3));

        // Cleanup secondary index and cache time
        foreach ($this->cacheIndex as $index => $key) {
            if (!isset($this->cache[$key])) {
                unset($this->cacheIndex[$index], $this->cacheTime[$key]);
            }
        }
    }
}


1			<?php
2
3			/**
4			* File containing MetadataCachePool class.
5			*
6			* @copyright Copyright (C) eZ Systems AS. All rights reserved.
7			* @license For full copyright and license information view LICENSE file distributed with this source code.
8			*/
9			declare(strict_types=1);
10
11			namespace eZ\Publish\Core\Persistence\Cache\InMemory;
12
13			/**
14			* Simple In-Memory Cache Pool.
15			*
16			* Could be used as separate instances for different use cases with a shared global expiry when applicable.
17			*
18			* Allow to use one instance with low ttl (200-600 milliseconds) and limited items (~100) dedicated to content (and
19			* related classes) to handle burst caching, and a separate instance with longer ttl (3-10sec) and separate limit (~200)
20			* for meta values like content type, section, ... to handle repeated lookups for these seldom changing values.
21			*
22			* @internal Only for use in eZ\Publish\Core\Persistence\Cache\AbstractInMemoryHandler, may change depending on needs there.
23			*/
24			class InMemoryCache
25			{
26			/**
27			* @var float Cache Time to Live, in seconds. This is only for how long we keep cache object around in-memory.
28			*/
29			private $ttl;
30
31			/**
32			* @var int The limit of objects in cache pool at a given time
33			*/
34			private $limit;
35
36			/**
37			* @var bool Switch for enabeling/disabling in-memory cache
38			*/
39			private $enabled;
40
41			/**
42			* Cache objects by primary key.
43			*
44			* @var object[]
45			*/
46			private $cache = [];
47
48			/**
49			* @var float[] Timestamp (float microtime) for individual cache by primary key.
50			*/
51			private $cacheTime = [];
52
53			/**
54			* Mapping of secondary index to primary key.
55			*
56			* @var string[]
57			*/
58			private $cacheIndex = [];
59
60			/**
61			* @var float\|null Micro timestamp with time clear($global=true) has been called to synchronize across cache pools.
62			*/
63			private $cacheExpiryTime;
64			protected static $globalCacheExpiry;
65
66			/**
67			* Language Cache constructor.
68			*
69			* @param float $ttl Seconds for the cache to live as a float, by default 0.3 (300 milliseconds)
70			* @param int $limit Limit for values to keep in cache, by default 100 cache values (per pool instance).
71			* @param bool $enabled For use by configuration to be able to disable or enable depending on needs.
72			*/
73			public function __construct(float $ttl = 0.3, int $limit = 100, bool $enabled = true)
74			{
75			$this->ttl = $ttl;
76			$this->limit = $limit;
77			$this->enabled = $enabled;
78			}
79
80			/**
81			* Returns a cache objects.
82			*
83			* @param string $key Primary or secondary index to look for cache on.
84			*
85			* @return object\|null Object if found, null if not.
86			*/
87			public function get(string $key)
88			{
89			if ($this->enabled === false) {
90			return null;
91			}
92
93			// Check for global expiry change, if the case clear cache
94			if ($this->cacheExpiryTime !== self::$globalCacheExpiry) {
95			$this->clear();
96			$this->cacheExpiryTime = self::$globalCacheExpiry;
97
98			return null;
99			}
100
101			$index = $this->cacheIndex[$key] ?? $key;
102			if (!isset($this->cache[$index]) \|\| $this->cacheTime[$index] + $this->ttl < microtime(true)) {
103			return null;
104			}
105
106			return $this->cache[$index];
107			}
108
109			/**
110			* Set object in in-memory cache.
111			*
112			* Should only set Cache hits here!
113			*
114			* @param object[] $objects
115			* @param callable $objectIndexes Return array of indexes per object (first argument), must return at least 1 primary index
116			* @param string\|null $listIndex Optional index for list of items
117			*/
118			public function setMulti(array $objects, callable $objectIndexes, string $listIndex = null): void
119			{
120			// If objects accounts for more then 20% of our limit, assume it's bulk content load and skip saving in-memory
121			if ($this->enabled === false \|\| \count($objects) >= $this->limit / 5) {
122			return;
123			}
124
125			// check if we will reach limit by adding these objects, if so remove old cache
126			if (\count($this->cache) + \count($objects) >= $this->limit) {
127			$this->vacuum();
128			}
129
130			$time = microtime(true);
131
132			// if set add objects to cache on list index (typically a "all" key)
133			if ($listIndex) {
			0 ignored issues – show Bug Best Practice introduced 2019-03-01 16:41 UTC by Report Bug Copy Issue Report The expression `$listIndex` of type `null\|string` is loosely compared to `true`; this is ambiguous if the string can be empty. You might want to explicitly use `!== null` instead. In PHP, under loose comparison (like `==`, or `!=`, or `switch` conditions), values of different types might be equal. For `string` values, the empty string `''` is a special case, in particular the following results might be unexpected: '' == false // true '' == null // true 'ab' == false // false 'ab' == null // false // It is often better to use strict comparison '' === false // false '' === null // false Loading history...
134			$this->cache[$listIndex] = $objects;
135			$this->cacheTime[$listIndex] = $time;
136			}
137
138			foreach ($objects as $object) {
139			// Skip if there are no indexes
140			if (!$indexes = $objectIndexes($object)) {
141			continue;
142			}
143
144			$key = array_shift($indexes);
145			$this->cache[$key] = $object;
146			$this->cacheTime[$key] = $time;
147
148			foreach ($indexes as $index) {
149			$this->cacheIndex[$index] = $key;
150			}
151			}
152			}
153
154			/**
155			* Removes multiple in-memory cache from the pool.
156			*
157			* @param string[] $keys An array of keys that should be removed from the pool.
158			*/
159			public function deleteMulti(array $keys): void
160			{
161			if ($this->enabled === false) {
162			return;
163			}
164
165			foreach ($keys as $key) {
166			if ($index = $this->cacheIndex[$key] ?? null) {
167			unset($this->cacheIndex[$key], $this->cache[$index], $this->cacheTime[$index]);
168			} else {
169			unset($this->cache[$key], $this->cacheTime[$key]);
170			}
171			}
172			}
173
174			/**
175			* Deletes all cache in the in-memory pool.
176			*/
177			public function clear(bool $global = false): void
178			{
179			// On purpose does not check if enabled, in case of several instances we allow clearing cache
180			$this->cache = $this->cacheIndex = $this->cacheTime = [];
181			if ($global) {
182			$this->cacheExpiryTime = self::$globalCacheExpiry = microtime(true);
183			}
184			}
185
186			/**
187			* Call to reduce cache items when $limit has been reached.
188			*
189			* Deletes expired first, then oldest(or least used?).
190			*/
191			private function vacuum(): void
192			{
193			// Vacuuming cache in bulk, clearing the 33% oldest cache values
194			$this->cache = \array_slice($this->cache, \floor($this->limit / 3));
195
196			// Cleanup secondary index and cache time
197			foreach ($this->cacheIndex as $index => $key) {
198			if (!isset($this->cache[$key])) {
199			unset($this->cacheIndex[$index], $this->cacheTime[$key]);
200			}
201			}
202			}
203			}
204

ezsystems / ezpublish-kernel

Push — in-memory-cache2 ( 0f2241...bf3815 )

InMemoryCache::__construct() A

Complexity

Size

Duplication

Importance

Duplication Side-by-Side

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