InMemoryCacheAdapter::saveCacheHitsInMemory() - Code Metrics - Inspection of "Fix generator handling on getItems(), also return..." - ezsystems/ezpublish-kernel - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — in-memory-cache ( 3245f0...8b8156 )

by André

created 2018-09-21 11:35 UTC

InMemoryCacheAdapter::saveCacheHitsInMemory() B

↳ Parent: InMemoryCacheAdapter

Complexity

Conditions	9
Paths	17

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	9
nc	17
nop	1
dl	0
loc	49
rs	7.5571
c	0
b	0
f	0

<?php

/**
 * File containing the ContentHandler implementation.
 *
 * @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\Adapter;

use eZ\Publish\SPI\Persistence\Content;
use eZ\Publish\SPI\Variation\Values\Variation;
use Symfony\Component\Cache\Adapter\TagAwareAdapterInterface;
use Psr\Cache\CacheItemInterface;

final class InMemoryCacheAdapter implements TagAwareAdapterInterface
{
    /**
     * Default limits to in-memory cache usage, max objects cached and max ttl to live in-memory.
     */
    private const LIMIT = 100;
    private const TTL = 10;

    /**
     * Indication of content classes for cache discrimination.
     *
     * By design we prefer to keep meta info (type, sections, ..) in cache for as long as possible and rather cleanup
     * cache representing content when we need to vacuum the cache (when reaching limits) first.
     *
     * Reason for that is:
     * - meta data more likely to be attempted to be loaded again
     * - content more likely to get updates more frequently
     *
     * So for those reasons content in-memory cache only aims to cache content for short bursts where code typically
     * deals with a given content before it moves on to the next, while keeping meta cache around for a bit longer.
     */
    private const CONTENT_CLASSES = [
        Content::class,
        Content\ContentInfo::class,
        Content\Location::class, // Will also match Content\Location\Trashed
        Content\VersionInfo::class,
        Content\Relation::class,
        Variation::class,
    ];

    /**
     * @var \Symfony\Component\Cache\CacheItem[] Cache of cache items by their keys.
     */
    private $cacheItems = [];

    /**
     * @var array Timestamp per cache key for TTL checks.
     */
    private $cacheItemsTS = [];

    /**
     * @var TagAwareAdapterInterface
     */
    private $inner;

    /**
     * @var int
     */
    private $limit;

    /**
     * @var int
     */
    private $ttl;

    public function __construct(TagAwareAdapterInterface $inner, int $limit = self::LIMIT, int $ttl = self::TTL)
    {
        $this->inner = $inner;
        $this->limit = $limit;
        $this->ttl = $ttl;
    }

    public function getItem($key)
    {
        if ($items = $this->getValidInMemoryCacheItems([$key])) {
            return $items[$key];
        }

        $item = $this->inner->getItem($key);
        if ($item->isHit()) {
            $this->saveCacheHitsInMemory([$key => $item]);
        }

        return $item;
    }

    public function getItems(array $keys = [])
    {
        $missingKeys = [];
        foreach($this->getValidInMemoryCacheItems($keys, $missingKeys) as $key => $item) {
            yield $key => $item;
        }

        if (!empty($missingKeys)) {
            $hits = [];
            $items = $this->inner->getItems($missingKeys);
            foreach ($items as $key => $item) {
                yield $key => $item;

                if ($item->isHit()) {
                    $hits[$key] = $item;
                }
            }

            $this->saveCacheHitsInMemory($hits);
        }
    }

    public function hasItem($key)
    {
        // We are not interested in trying to cache if we don't have the item, but if we do we can return true
        if (isset($this->cacheItems[$key])) {
            return true;
        }

        return $this->inner->hasItem($key);
    }

    public function clear()
    {
        $this->cacheItems = [];
        $this->cacheItemsTS = [];

        return $this->inner->clear();
    }

    public function deleteItem($key)
    {
        if (isset($this->cacheItems[$key])) {
            unset($this->cacheItems[$key], $this->cacheItemsTS[$key]);
        }

        return $this->inner->deleteItem($key);
    }

    public function deleteItems(array $keys)
    {
        foreach ($keys as $key) {
            if (isset($this->cacheItems[$key])) {
                unset($this->cacheItems[$key], $this->cacheItemsTS[$key]);
            }
        }

        return $this->inner->deleteItems($keys);
    }

    public function save(CacheItemInterface $item)
    {
        $this->saveCacheHitsInMemory([$item->getKey() => $item]);

        return $this->inner->save($item);
    }

    public function saveDeferred(CacheItemInterface $item)
    {
        // Symfony commits the deferred items as soon as getItem(s) is called on it later or on destruct.
        // So seems we can safely save in-memory, also we don't at the time of writing use saveDeferred().
        $this->saveCacheHitsInMemory([$item->getKey() => $item]);

        return $this->inner->saveDeferred($item);
    }

    public function commit()
    {
        return $this->inner->commit();
    }

    public function invalidateTags(array $tags)
    {
        // Cleanup in-Memory cache items affected
        foreach ($this->cacheItems as $key => $item) {
            if (array_intersect($item->getPreviousTags(), $tags)) {
                unset($this->cacheItems[$key], $this->cacheItemsTS[$key]);
            }
        }

        return $this->inner->invalidateTags($tags);
    }

    /**
     * @param \Psr\Cache\CacheItemInterface[] $items Save Cache hits in-memory with cache key as array key.
     */
    private function saveCacheHitsInMemory(array $items): void
    {
        // Skip if empty
        if (empty($items)) {
            return;
        }

        // If items accounts for more then 20% of our limit, assume it's bulk content load and skip saving in-memory
        if (\count($items) >= $this->limit / 5) {
            return;
        }

        // Will we stay clear of the limit? If so return early
        if (\count($items) + \count($this->cacheItems) < $this->limit) {
            $this->cacheItems += $items;
            $this->cacheItemsTS += \array_fill_keys(\array_keys($items), \time());

            return;
        }

        // # Vacuuming cache in bulk so we don't end up doing this all the time
        // 1. Discriminate against content cache, remove up to 1/3 of max limit starting from oldest items
        $removeCount = 0;
        $removeTarget = floor($this->limit / 3);
        foreach ($this->cacheItems as $key => $item) {
            $cache = $item->get();
            foreach (self::CONTENT_CLASSES as $className) {
                if ($cache instanceof $className) {
                    unset($this->cacheItems[$key]);
                    ++$removeCount;

                    break;
                }
            }

            if ($removeCount >= $removeTarget) {
                break;
            }
        }

        // 2. Does cache still exceed the 80% of limit? if so remove everything above 66%
        // NOTE: This on purpose keeps the oldest cache around, getValidInMemoryCacheItems() handles ttl checks on that
        if (\count($this->cacheItems) >= $this->limit / 1.5) {
            $this->cacheItems = \array_slice($this->cacheItems, 0, floor($this->limit / 1.5));
        }

        $this->cacheItems += $items;
        $this->cacheItemsTS += \array_fill_keys(\array_keys($items), \time());
    }

    /**
     * @param array $keys
     * @param array $missingKeys
     *
     * @return array
     */
    public function getValidInMemoryCacheItems(array $keys = [], array &$missingKeys = []): array
    {
        // 1. Validate TTL and remove items that have exceeded it
        $expiredTime = time() - $this->ttl;
        foreach ($this->cacheItemsTS as $key => $ts) {
            if ($ts <= $expiredTime) {
                unset($this->cacheItemsTS[$key]);

                // Cache items might have been removed in saveInMemoryCacheItems() when enforcing limit
                if (isset($this->cacheItems[$key])) {
                    unset($this->cacheItems[$key]);
                }
            }
        }

        // 2. Get valid items
        $items = [];
        foreach ($keys as $key) {
            if (isset($this->cacheItems[$key])) {
                $items[$key] = $this->cacheItems[$key];
            } else {
                $missingKeys[] = $key;
            }
        }

        return $items;
    }
}


1			<?php
2
3			/**
4			* File containing the ContentHandler implementation.
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\Adapter;
12
13			use eZ\Publish\SPI\Persistence\Content;
14			use eZ\Publish\SPI\Variation\Values\Variation;
15			use Symfony\Component\Cache\Adapter\TagAwareAdapterInterface;
16			use Psr\Cache\CacheItemInterface;
17
18			final class InMemoryCacheAdapter implements TagAwareAdapterInterface
19			{
20			/**
21			* Default limits to in-memory cache usage, max objects cached and max ttl to live in-memory.
22			*/
23			private const LIMIT = 100;
24			private const TTL = 10;
25
26			/**
27			* Indication of content classes for cache discrimination.
28			*
29			* By design we prefer to keep meta info (type, sections, ..) in cache for as long as possible and rather cleanup
30			* cache representing content when we need to vacuum the cache (when reaching limits) first.
31			*
32			* Reason for that is:
33			* - meta data more likely to be attempted to be loaded again
34			* - content more likely to get updates more frequently
35			*
36			* So for those reasons content in-memory cache only aims to cache content for short bursts where code typically
37			* deals with a given content before it moves on to the next, while keeping meta cache around for a bit longer.
38			*/
39			private const CONTENT_CLASSES = [
40			Content::class,
41			Content\ContentInfo::class,
42			Content\Location::class, // Will also match Content\Location\Trashed
43			Content\VersionInfo::class,
44			Content\Relation::class,
45			Variation::class,
46			];
47
48			/**
49			* @var \Symfony\Component\Cache\CacheItem[] Cache of cache items by their keys.
50			*/
51			private $cacheItems = [];
52
53			/**
54			* @var array Timestamp per cache key for TTL checks.
55			*/
56			private $cacheItemsTS = [];
57
58			/**
59			* @var TagAwareAdapterInterface
60			*/
61			private $inner;
62
63			/**
64			* @var int
65			*/
66			private $limit;
67
68			/**
69			* @var int
70			*/
71			private $ttl;
72
73			public function __construct(TagAwareAdapterInterface $inner, int $limit = self::LIMIT, int $ttl = self::TTL)
74			{
75			$this->inner = $inner;
76			$this->limit = $limit;
77			$this->ttl = $ttl;
78			}
79
80			public function getItem($key)
81			{
82			if ($items = $this->getValidInMemoryCacheItems([$key])) {
83			return $items[$key];
84			}
85
86			$item = $this->inner->getItem($key);
87			if ($item->isHit()) {
88			$this->saveCacheHitsInMemory([$key => $item]);
89			}
90
91			return $item;
92			}
93
94			public function getItems(array $keys = [])
95			{
96			$missingKeys = [];
97			foreach($this->getValidInMemoryCacheItems($keys, $missingKeys) as $key => $item) {
98			yield $key => $item;
99			}
100
101			if (!empty($missingKeys)) {
102			$hits = [];
103			$items = $this->inner->getItems($missingKeys);
104			foreach ($items as $key => $item) {
105			yield $key => $item;
106
107			if ($item->isHit()) {
108			$hits[$key] = $item;
109			}
110			}
111
112			$this->saveCacheHitsInMemory($hits);
113			}
114			}
115
116			public function hasItem($key)
117			{
118			// We are not interested in trying to cache if we don't have the item, but if we do we can return true
119			if (isset($this->cacheItems[$key])) {
120			return true;
121			}
122
123			return $this->inner->hasItem($key);
124			}
125
126			public function clear()
127			{
128			$this->cacheItems = [];
129			$this->cacheItemsTS = [];
130
131			return $this->inner->clear();
132			}
133
134			public function deleteItem($key)
135			{
136			if (isset($this->cacheItems[$key])) {
137			unset($this->cacheItems[$key], $this->cacheItemsTS[$key]);
138			}
139
140			return $this->inner->deleteItem($key);
141			}
142
143			public function deleteItems(array $keys)
144			{
145			foreach ($keys as $key) {
146			if (isset($this->cacheItems[$key])) {
147			unset($this->cacheItems[$key], $this->cacheItemsTS[$key]);
148			}
149			}
150
151			return $this->inner->deleteItems($keys);
152			}
153
154			public function save(CacheItemInterface $item)
155			{
156			$this->saveCacheHitsInMemory([$item->getKey() => $item]);
157
158			return $this->inner->save($item);
159			}
160
161			public function saveDeferred(CacheItemInterface $item)
162			{
163			// Symfony commits the deferred items as soon as getItem(s) is called on it later or on destruct.
164			// So seems we can safely save in-memory, also we don't at the time of writing use saveDeferred().
165			$this->saveCacheHitsInMemory([$item->getKey() => $item]);
166
167			return $this->inner->saveDeferred($item);
168			}
169
170			public function commit()
171			{
172			return $this->inner->commit();
173			}
174
175			public function invalidateTags(array $tags)
176			{
177			// Cleanup in-Memory cache items affected
178			foreach ($this->cacheItems as $key => $item) {
179			if (array_intersect($item->getPreviousTags(), $tags)) {
180			unset($this->cacheItems[$key], $this->cacheItemsTS[$key]);
181			}
182			}
183
184			return $this->inner->invalidateTags($tags);
185			}
186
187			/**
188			* @param \Psr\Cache\CacheItemInterface[] $items Save Cache hits in-memory with cache key as array key.
189			*/
190			private function saveCacheHitsInMemory(array $items): void
191			{
192			// Skip if empty
193			if (empty($items)) {
194			return;
195			}
196
197			// If items accounts for more then 20% of our limit, assume it's bulk content load and skip saving in-memory
198			if (\count($items) >= $this->limit / 5) {
199			return;
200			}
201
202			// Will we stay clear of the limit? If so return early
203			if (\count($items) + \count($this->cacheItems) < $this->limit) {
204			$this->cacheItems += $items;
205			$this->cacheItemsTS += \array_fill_keys(\array_keys($items), \time());
206
207			return;
208			}
209
210			// # Vacuuming cache in bulk so we don't end up doing this all the time
211			// 1. Discriminate against content cache, remove up to 1/3 of max limit starting from oldest items
212			$removeCount = 0;
213			$removeTarget = floor($this->limit / 3);
214			foreach ($this->cacheItems as $key => $item) {
215			$cache = $item->get();
216			foreach (self::CONTENT_CLASSES as $className) {
217			if ($cache instanceof $className) {
218			unset($this->cacheItems[$key]);
219			++$removeCount;
220
221			break;
222			}
223			}
224
225			if ($removeCount >= $removeTarget) {
226			break;
227			}
228			}
229
230			// 2. Does cache still exceed the 80% of limit? if so remove everything above 66%
231			// NOTE: This on purpose keeps the oldest cache around, getValidInMemoryCacheItems() handles ttl checks on that
232			if (\count($this->cacheItems) >= $this->limit / 1.5) {
233			$this->cacheItems = \array_slice($this->cacheItems, 0, floor($this->limit / 1.5));
234			}
235
236			$this->cacheItems += $items;
237			$this->cacheItemsTS += \array_fill_keys(\array_keys($items), \time());
238			}
239
240			/**
241			* @param array $keys
242			* @param array $missingKeys
243			*
244			* @return array
245			*/
246			public function getValidInMemoryCacheItems(array $keys = [], array &$missingKeys = []): array
247			{
248			// 1. Validate TTL and remove items that have exceeded it
249			$expiredTime = time() - $this->ttl;
250			foreach ($this->cacheItemsTS as $key => $ts) {
251			if ($ts <= $expiredTime) {
252			unset($this->cacheItemsTS[$key]);
253
254			// Cache items might have been removed in saveInMemoryCacheItems() when enforcing limit
255			if (isset($this->cacheItems[$key])) {
256			unset($this->cacheItems[$key]);
257			}
258			}
259			}
260
261			// 2. Get valid items
262			$items = [];
263			foreach ($keys as $key) {
264			if (isset($this->cacheItems[$key])) {
265			$items[$key] = $this->cacheItems[$key];
266			} else {
267			$missingKeys[] = $key;
268			}
269			}
270
271			return $items;
272			}
273			}
274

ezsystems / ezpublish-kernel

Push — in-memory-cache ( 3245f0...8b8156 )

InMemoryCacheAdapter::saveCacheHitsInMemory() B

Complexity

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Duplication

Importance

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