1<?php
2/*
3 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
4 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
5 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
6 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
7 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
8 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
9 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
10 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
11 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
12 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
13 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
14 *
15 * This software consists of voluntary contributions made by many individuals
16 * and is licensed under the MIT license. For more information, see
17 * <http://www.doctrine-project.org>.
18 */
19
20namespace Doctrine\Common\Cache;
21
22use \Memcache;
23
24/**
25 * Memcache cache provider.
26 *
27 * @link   www.doctrine-project.org
28 * @since  2.0
29 * @author Benjamin Eberlei <kontakt@beberlei.de>
30 * @author Guilherme Blanco <guilhermeblanco@hotmail.com>
31 * @author Jonathan Wage <jonwage@gmail.com>
32 * @author Roman Borschel <roman@code-factory.org>
33 * @author David Abdemoulaie <dave@hobodave.com>
34 */
35class MemcacheCache extends CacheProvider
36{
37    /**
38     * @var Memcache|null
39     */
40    private $memcache;
41
42    /**
43     * Sets the memcache instance to use.
44     *
45     * @param Memcache $memcache
46     *
47     * @return void
48     */
49    public function setMemcache(Memcache $memcache)
50    {
51        $this->memcache = $memcache;
52    }
53
54    /**
55     * Gets the memcache instance used by the cache.
56     *
57     * @return Memcache|null
58     */
59    public function getMemcache()
60    {
61        return $this->memcache;
62    }
63
64    /**
65     * {@inheritdoc}
66     */
67    protected function doFetch($id)
68    {
69        return $this->memcache->get($id);
70    }
71
72    /**
73     * {@inheritdoc}
74     */
75    protected function doContains($id)
76    {
77        $flags = null;
78        $this->memcache->get($id, $flags);
79
80        //if memcache has changed the value of "flags", it means the value exists
81        return ($flags !== null);
82    }
83
84    /**
85     * {@inheritdoc}
86     */
87    protected function doSave($id, $data, $lifeTime = 0)
88    {
89        if ($lifeTime > 30 * 24 * 3600) {
90            $lifeTime = time() + $lifeTime;
91        }
92        return $this->memcache->set($id, $data, 0, (int) $lifeTime);
93    }
94
95    /**
96     * {@inheritdoc}
97     */
98    protected function doDelete($id)
99    {
100        // Memcache::delete() returns false if entry does not exist
101        return $this->memcache->delete($id) || ! $this->doContains($id);
102    }
103
104    /**
105     * {@inheritdoc}
106     */
107    protected function doFlush()
108    {
109        return $this->memcache->flush();
110    }
111
112    /**
113     * {@inheritdoc}
114     */
115    protected function doGetStats()
116    {
117        $stats = $this->memcache->getStats();
118        return array(
119            Cache::STATS_HITS   => $stats['get_hits'],
120            Cache::STATS_MISSES => $stats['get_misses'],
121            Cache::STATS_UPTIME => $stats['uptime'],
122            Cache::STATS_MEMORY_USAGE     => $stats['bytes'],
123            Cache::STATS_MEMORY_AVAILABLE => $stats['limit_maxbytes'],
124        );
125    }
126}
127