Completed
Push — master ( 8b6bb0...9b3eef )
by Morris
09:38
created

Redis::__construct()   A

Complexity

Conditions 2
Paths 2

Size

Total Lines 6
Code Lines 4

Duplication

Lines 0
Ratio 0 %

Importance

Changes 1
Bugs 0 Features 0
Metric Value
c 1
b 0
f 0
dl 0
loc 6
rs 9.4285
cc 2
eloc 4
nc 2
nop 1
1
<?php
2
/**
3
 * @author Joas Schilling <[email protected]>
4
 * @author Jörn Friedrich Dreyer <[email protected]>
5
 * @author Lukas Reschke <[email protected]>
6
 * @author Michael Telatynski <[email protected]>
7
 * @author Morris Jobke <[email protected]>
8
 * @author Robin Appelman <[email protected]>
9
 *
10
 * @copyright Copyright (c) 2016, ownCloud, Inc.
11
 * @license AGPL-3.0
12
 *
13
 * This code is free software: you can redistribute it and/or modify
14
 * it under the terms of the GNU Affero General Public License, version 3,
15
 * as published by the Free Software Foundation.
16
 *
17
 * This program is distributed in the hope that it will be useful,
18
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20
 * GNU Affero General Public License for more details.
21
 *
22
 * You should have received a copy of the GNU Affero General Public License, version 3,
23
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
24
 *
25
 */
26
27
namespace OC\Memcache;
28
29
use OCP\IMemcacheTTL;
30
31
class Redis extends Cache implements IMemcacheTTL {
32
	/**
33
	 * @var \Redis $cache
34
	 */
35
	private static $cache = null;
36
37
	public function __construct($prefix = '') {
38
		parent::__construct($prefix);
39
		if (is_null(self::$cache)) {
40
			self::$cache = \OC::$server->getGetRedisFactory()->getInstance();
41
		}
42
	}
43
44
	/**
45
	 * entries in redis get namespaced to prevent collisions between ownCloud instances and users
46
	 */
47
	protected function getNameSpace() {
48
		return $this->prefix;
49
	}
50
51
	public function get($key) {
52
		$result = self::$cache->get($this->getNamespace() . $key);
53
		if ($result === false && !self::$cache->exists($this->getNamespace() . $key)) {
54
			return null;
55
		} else {
56
			return json_decode($result, true);
57
		}
58
	}
59
60
	public function set($key, $value, $ttl = 0) {
61
		if ($ttl > 0) {
62
			return self::$cache->setex($this->getNamespace() . $key, $ttl, json_encode($value));
63
		} else {
64
			return self::$cache->set($this->getNamespace() . $key, json_encode($value));
65
		}
66
	}
67
68
	public function hasKey($key) {
69
		return self::$cache->exists($this->getNamespace() . $key);
70
	}
71
72
	public function remove($key) {
73
		if (self::$cache->delete($this->getNamespace() . $key)) {
74
			return true;
75
		} else {
76
			return false;
77
		}
78
	}
79
80
	public function clear($prefix = '') {
81
		$prefix = $this->getNamespace() . $prefix . '*';
82
		$it = null;
83
		self::$cache->setOption(\Redis::OPT_SCAN, \Redis::SCAN_RETRY);
84
		while ($keys = self::$cache->scan($it, $prefix)) {
85
			self::$cache->delete($keys);
86
		}
87
		return true;
88
	}
89
90
	/**
91
	 * Set a value in the cache if it's not already stored
92
	 *
93
	 * @param string $key
94
	 * @param mixed $value
95
	 * @param int $ttl Time To Live in seconds. Defaults to 60*60*24
96
	 * @return bool
97
	 */
98
	public function add($key, $value, $ttl = 0) {
99
		// don't encode ints for inc/dec
100
		if (!is_int($value)) {
101
			$value = json_encode($value);
102
		}
103
		return self::$cache->setnx($this->getPrefix() . $key, $value);
104
	}
105
106
	/**
107
	 * Increase a stored number
108
	 *
109
	 * @param string $key
110
	 * @param int $step
111
	 * @return int | bool
112
	 */
113
	public function inc($key, $step = 1) {
114
		return self::$cache->incrBy($this->getNamespace() . $key, $step);
115
	}
116
117
	/**
118
	 * Decrease a stored number
119
	 *
120
	 * @param string $key
121
	 * @param int $step
122
	 * @return int | bool
123
	 */
124
	public function dec($key, $step = 1) {
125
		if (!$this->hasKey($key)) {
126
			return false;
0 ignored issues
show
Bug Best Practice introduced by
The return type of return false; (false) is incompatible with the return type declared by the interface OCP\IMemcache::dec of type integer.

If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.

Let’s take a look at an example:

class Author {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

abstract class Post {
    public function getAuthor() {
        return 'Johannes';
    }
}

class BlogPost extends Post {
    public function getAuthor() {
        return new Author('Johannes');
    }
}

class ForumPost extends Post { /* ... */ }

function my_function(Post $post) {
    echo strtoupper($post->getAuthor());
}

Our function my_function expects a Post object, and outputs the author of the post. The base class Post returns a simple string and outputting a simple string will work just fine. However, the child class BlogPost which is a sub-type of Post instead decided to return an object, and is therefore violating the SOLID principles. If a BlogPost were passed to my_function, PHP would not complain, but ultimately fail when executing the strtoupper call in its body.

Loading history...
127
		}
128
		return self::$cache->decrBy($this->getNamespace() . $key, $step);
129
	}
130
131
	/**
132
	 * Compare and set
133
	 *
134
	 * @param string $key
135
	 * @param mixed $old
136
	 * @param mixed $new
137
	 * @return bool
138
	 */
139
	public function cas($key, $old, $new) {
140
		if (!is_int($new)) {
141
			$new = json_encode($new);
142
		}
143
		self::$cache->watch($this->getNamespace() . $key);
144 View Code Duplication
		if ($this->get($key) === $old) {
0 ignored issues
show
Duplication introduced by
This code seems to be duplicated across your project.

Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation.

You can also find more detailed suggestions in the “Code” section of your repository.

Loading history...
145
			$result = self::$cache->multi()
146
				->set($this->getNamespace() . $key, $new)
147
				->exec();
148
			return ($result === false) ? false : true;
149
		}
150
		self::$cache->unwatch();
151
		return false;
152
	}
153
154
	/**
155
	 * Compare and delete
156
	 *
157
	 * @param string $key
158
	 * @param mixed $old
159
	 * @return bool
160
	 */
161
	public function cad($key, $old) {
162
		self::$cache->watch($this->getNamespace() . $key);
163 View Code Duplication
		if ($this->get($key) === $old) {
0 ignored issues
show
Duplication introduced by
This code seems to be duplicated across your project.

Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation.

You can also find more detailed suggestions in the “Code” section of your repository.

Loading history...
164
			$result = self::$cache->multi()
165
				->del($this->getNamespace() . $key)
166
				->exec();
167
			return ($result === false) ? false : true;
168
		}
169
		self::$cache->unwatch();
170
		return false;
171
	}
172
173
	public function setTTL($key, $ttl) {
174
		self::$cache->expire($this->getNamespace() . $key, $ttl);
175
	}
176
177
	static public function isAvailable() {
178
		return \OC::$server->getGetRedisFactory()->isAvailable();
179
	}
180
}
181
182