Shard::getShard() - Code Metrics - matthiasmullie/scrapbook - Measure and Improve Code Quality continuously with Scrutinizer

Shard::getShard() A
last analyzed 2022-11-07 14:18 UTC

↳ Parent: Shard

Complexity

Conditions	1
Paths	1

Size

Total Lines	20
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Importance

Changes	2
Bugs	0	Features	0

Metric	Value
cc	1
eloc	4
c	2
b	0
f	0
nc	1
nop	1
dl	0
loc	20
rs	10

<?php

namespace MatthiasMullie\Scrapbook\Scale;

use MatthiasMullie\Scrapbook\KeyValueStore;
use SplObjectStorage;

/**
 * This class lets you scale your cache cluster by sharding the data across
 * multiple cache servers.
 *
 * Pass the individual KeyValueStore objects that compose the cache server pool
 * into this constructor how you want the data to be sharded. The cache data
 * will be sharded over them according to the order they were in when they were
 * passed into this constructor (so make sure to always keep the order the same)
 *
 * The sharding is spread evenly and all cache servers will roughly receive the
 * same amount of cache keys. If some servers are bigger than others, you can
 * offset this by adding the KeyValueStore object more than once.
 *
 * Data can even be sharded among different adapters: one server in the shard
 * pool can be Redis while another can be Memcached. Not sure why you would even
 * want that, but you could!
 *
 * @author Matthias Mullie <[email protected]>
 * @copyright Copyright (c) 2014, Matthias Mullie. All rights reserved
 * @license LICENSE MIT
 */
class Shard implements KeyValueStore
{
    /**
     * @var KeyValueStore[]
     */
    protected $caches = array();

    /**
     * Overloadable with multiple KeyValueStore objects.
     */
    public function __construct(KeyValueStore $cache1, KeyValueStore $cache2 = null /* , [KeyValueStore $cache3, [...]] */)
    {
        $caches = func_get_args();
        $caches = array_filter($caches);
        $this->caches = $caches;
    }

    public function addCache(KeyValueStore $cache)
    {
        $this->caches[] = $cache;
    }

    /**
     * {@inheritdoc}
     */
    public function get($key, &$token = null)
    {
        return $this->getShard($key)->get($key, $token);
    }

    /**
     * {@inheritdoc}
     */
    public function getMulti(array $keys, array &$tokens = null)
    {
        $shards = $this->getShards($keys);
        $results = array();
        $tokens = array();

        /** @var KeyValueStore $shard */
        foreach ($shards as $shard) {
            $keysOnShard = $shards[$shard];
            $results += $shard->getMulti($keysOnShard, $shardTokens);

            $tokens += $shardTokens ?: array();
        }

        return $results;
    }

    /**
     * {@inheritdoc}
     */
    public function set($key, $value, $expire = 0)
    {
        return $this->getShard($key)->set($key, $value, $expire);
    }

    /**
     * {@inheritdoc}
     */
    public function setMulti(array $items, $expire = 0)
    {
        $shards = $this->getShards(array_keys($items));
        $results = array();

        /** @var KeyValueStore $shard */
        foreach ($shards as $shard) {
            $keysOnShard = $shards[$shard];
            $itemsOnShard = array_intersect_key($items, array_flip($keysOnShard));
            $results += $shard->setMulti($itemsOnShard, $expire);
        }

        return $results;
    }

    /**
     * {@inheritdoc}
     */
    public function delete($key)
    {
        return $this->getShard($key)->delete($key);
    }

    /**
     * {@inheritdoc}
     */
    public function deleteMulti(array $keys)
    {
        $shards = $this->getShards($keys);
        $results = array();

        /** @var KeyValueStore $shard */
        foreach ($shards as $shard) {
            $keysOnShard = $shards[$shard];
            $results += $shard->deleteMulti($keysOnShard);
        }

        return $results;
    }

    /**
     * {@inheritdoc}
     */
    public function add($key, $value, $expire = 0)
    {
        return $this->getShard($key)->add($key, $value, $expire);
    }

    /**
     * {@inheritdoc}
     */
    public function replace($key, $value, $expire = 0)
    {
        return $this->getShard($key)->replace($key, $value, $expire);
    }

    /**
     * {@inheritdoc}
     */
    public function cas($token, $key, $value, $expire = 0)
    {
        return $this->getShard($key)->cas($token, $key, $value, $expire);
    }

    /**
     * {@inheritdoc}
     */
    public function increment($key, $offset = 1, $initial = 0, $expire = 0)
    {
        return $this->getShard($key)->increment($key, $offset, $initial, $expire);
    }

    /**
     * {@inheritdoc}
     */
    public function decrement($key, $offset = 1, $initial = 0, $expire = 0)
    {
        return $this->getShard($key)->decrement($key, $offset, $initial, $expire);
    }

    /**
     * {@inheritdoc}
     */
    public function touch($key, $expire)
    {
        return $this->getShard($key)->touch($key, $expire);
    }

    /**
     * {@inheritdoc}
     */
    public function flush()
    {
        $result = true;

        foreach ($this->caches as $cache) {
            $result &= $cache->flush();
        }

        return (bool) $result;
    }

    /**
     * {@inheritdoc}
     */
    public function getCollection($name)
    {
        $shard = new static($this->caches[0]->getCollection($name));

        $count = count($this->caches);
        for ($i = 1; $i < $count; ++$i) {
            $shard->addCache($this->caches[$i]->getCollection($name));
        }

        return $shard;
    }

    /**
     * Get the shard (KeyValueStore object) that corresponds to a particular
     * cache key.
     *
     * @param string $key
     *
     * @return KeyValueStore
     */
    protected function getShard($key)
    {
        /*
         * The hash is so we can deterministically randomize the spread of keys
         * over servers: if we were to just spread them based on key name, we
         * may end up with a large chunk of similarly prefixed keys on the same
         * server. Hashing the key will ensure similar looking keys can still
         * result in very different values, yet they result will be the same
         * every time it's repeated for the same key.
         * Since we don't use the hash for encryption, the fastest algorithm
         * will do just fine here.
         */
        $hash = crc32($key);

        // crc32 on 32-bit machines can produce a negative int
        $hash = abs($hash);

        $index = $hash % count($this->caches);

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

    /**
     * Get a [KeyValueStore => array of cache keys] map (SplObjectStorage) for
     * multiple cache keys.
     *
     * @return \SplObjectStorage
     */
    protected function getShards(array $keys)
    {
        $shards = new \SplObjectStorage();

        foreach ($keys as $key) {
            $shard = $this->getShard($key);
            if (!isset($shards[$shard])) {
                $shards[$shard] = array();
            }

            $shards[$shard] = array_merge($shards[$shard], array($key));
        }

        return $shards;
    }
}


1			<?php
2
3			namespace MatthiasMullie\Scrapbook\Scale;
4
5			use MatthiasMullie\Scrapbook\KeyValueStore;
6			use SplObjectStorage;
7
8			/**
9			* This class lets you scale your cache cluster by sharding the data across
10			* multiple cache servers.
11			*
12			* Pass the individual KeyValueStore objects that compose the cache server pool
13			* into this constructor how you want the data to be sharded. The cache data
14			* will be sharded over them according to the order they were in when they were
15			* passed into this constructor (so make sure to always keep the order the same)
16			*
17			* The sharding is spread evenly and all cache servers will roughly receive the
18			* same amount of cache keys. If some servers are bigger than others, you can
19			* offset this by adding the KeyValueStore object more than once.
20			*
21			* Data can even be sharded among different adapters: one server in the shard
22			* pool can be Redis while another can be Memcached. Not sure why you would even
23			* want that, but you could!
24			*
25			* @author Matthias Mullie <[email protected]>
26			* @copyright Copyright (c) 2014, Matthias Mullie. All rights reserved
27			* @license LICENSE MIT
28			*/
29			class Shard implements KeyValueStore
30			{
31			/**
32			* @var KeyValueStore[]
33			*/
34			protected $caches = array();
35
36			/**
37			* Overloadable with multiple KeyValueStore objects.
38			*/
39			public function __construct(KeyValueStore $cache1, KeyValueStore $cache2 = null /* , [KeyValueStore $cache3, [...]] */)
40			{
41			$caches = func_get_args();
42			$caches = array_filter($caches);
43			$this->caches = $caches;
44			}
45
46			public function addCache(KeyValueStore $cache)
47			{
48			$this->caches[] = $cache;
49			}
50
51			/**
52			* {@inheritdoc}
53			*/
54			public function get($key, &$token = null)
55			{
56			return $this->getShard($key)->get($key, $token);
57			}
58
59			/**
60			* {@inheritdoc}
61			*/
62			public function getMulti(array $keys, array &$tokens = null)
63			{
64			$shards = $this->getShards($keys);
65			$results = array();
66			$tokens = array();
67
68			/** @var KeyValueStore $shard */
69			foreach ($shards as $shard) {
70			$keysOnShard = $shards[$shard];
71			$results += $shard->getMulti($keysOnShard, $shardTokens);
			0 ignored issues – show Comprehensibility Best Practice introduced 2022-11-07 14:11 UTC by Report Bug Copy Issue Report The variable `$shardTokens` seems to be never defined. Loading history...
72			$tokens += $shardTokens ?: array();
73			}
74
75			return $results;
76			}
77
78			/**
79			* {@inheritdoc}
80			*/
81			public function set($key, $value, $expire = 0)
82			{
83			return $this->getShard($key)->set($key, $value, $expire);
84			}
85
86			/**
87			* {@inheritdoc}
88			*/
89			public function setMulti(array $items, $expire = 0)
90			{
91			$shards = $this->getShards(array_keys($items));
92			$results = array();
93
94			/** @var KeyValueStore $shard */
95			foreach ($shards as $shard) {
96			$keysOnShard = $shards[$shard];
97			$itemsOnShard = array_intersect_key($items, array_flip($keysOnShard));
98			$results += $shard->setMulti($itemsOnShard, $expire);
99			}
100
101			return $results;
102			}
103
104			/**
105			* {@inheritdoc}
106			*/
107			public function delete($key)
108			{
109			return $this->getShard($key)->delete($key);
110			}
111
112			/**
113			* {@inheritdoc}
114			*/
115			public function deleteMulti(array $keys)
116			{
117			$shards = $this->getShards($keys);
118			$results = array();
119
120			/** @var KeyValueStore $shard */
121			foreach ($shards as $shard) {
122			$keysOnShard = $shards[$shard];
123			$results += $shard->deleteMulti($keysOnShard);
124			}
125
126			return $results;
127			}
128
129			/**
130			* {@inheritdoc}
131			*/
132			public function add($key, $value, $expire = 0)
133			{
134			return $this->getShard($key)->add($key, $value, $expire);
135			}
136
137			/**
138			* {@inheritdoc}
139			*/
140			public function replace($key, $value, $expire = 0)
141			{
142			return $this->getShard($key)->replace($key, $value, $expire);
143			}
144
145			/**
146			* {@inheritdoc}
147			*/
148			public function cas($token, $key, $value, $expire = 0)
149			{
150			return $this->getShard($key)->cas($token, $key, $value, $expire);
151			}
152
153			/**
154			* {@inheritdoc}
155			*/
156			public function increment($key, $offset = 1, $initial = 0, $expire = 0)
157			{
158			return $this->getShard($key)->increment($key, $offset, $initial, $expire);
159			}
160
161			/**
162			* {@inheritdoc}
163			*/
164			public function decrement($key, $offset = 1, $initial = 0, $expire = 0)
165			{
166			return $this->getShard($key)->decrement($key, $offset, $initial, $expire);
167			}
168
169			/**
170			* {@inheritdoc}
171			*/
172			public function touch($key, $expire)
173			{
174			return $this->getShard($key)->touch($key, $expire);
175			}
176
177			/**
178			* {@inheritdoc}
179			*/
180			public function flush()
181			{
182			$result = true;
183
184			foreach ($this->caches as $cache) {
185			$result &= $cache->flush();
186			}
187
188			return (bool) $result;
189			}
190
191			/**
192			* {@inheritdoc}
193			*/
194			public function getCollection($name)
195			{
196			$shard = new static($this->caches[0]->getCollection($name));
197
198			$count = count($this->caches);
199			for ($i = 1; $i < $count; ++$i) {
200			$shard->addCache($this->caches[$i]->getCollection($name));
201			}
202
203			return $shard;
204			}
205
206			/**
207			* Get the shard (KeyValueStore object) that corresponds to a particular
208			* cache key.
209			*
210			* @param string $key
211			*
212			* @return KeyValueStore
213			*/
214			protected function getShard($key)
215			{
216			/*
217			* The hash is so we can deterministically randomize the spread of keys
218			* over servers: if we were to just spread them based on key name, we
219			* may end up with a large chunk of similarly prefixed keys on the same
220			* server. Hashing the key will ensure similar looking keys can still
221			* result in very different values, yet they result will be the same
222			* every time it's repeated for the same key.
223			* Since we don't use the hash for encryption, the fastest algorithm
224			* will do just fine here.
225			*/
226			$hash = crc32($key);
227
228			// crc32 on 32-bit machines can produce a negative int
229			$hash = abs($hash);
230
231			$index = $hash % count($this->caches);
232
233			return $this->caches[$index];
234			}
235
236			/**
237			* Get a [KeyValueStore => array of cache keys] map (SplObjectStorage) for
238			* multiple cache keys.
239			*
240			* @return \SplObjectStorage
241			*/
242			protected function getShards(array $keys)
243			{
244			$shards = new \SplObjectStorage();
245
246			foreach ($keys as $key) {
247			$shard = $this->getShard($key);
248			if (!isset($shards[$shard])) {
249			$shards[$shard] = array();
250			}
251
252			$shards[$shard] = array_merge($shards[$shard], array($key));
253			}
254
255			return $shards;
256			}
257			}
258

matthiasmullie / scrapbook

Shard::getShard() A last analyzed 2022-11-07 14:18 UTC

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Shard::getShard() A
last analyzed 2022-11-07 14:18 UTC