src/Core/Cache/MemcachedCacheDriver.php

   1 <?php
   2
   3 namespace Friendica\Core\Cache;
   4
   5 use Friendica\Core\Cache;
   6
   7 use Exception;
   8 use Memcached;
   9
  10 /**
  11  * Memcached Cache Driver
  12  *
  13  * @author Hypolite Petovan <mrpetovan@gmail.com>
  14  */
  15 class MemcachedCacheDriver extends AbstractCacheDriver implements IMemoryCacheDriver
  16 {
  17         use TraitCompareSet;
  18         use TraitCompareDelete;
  19
  20         /**
  21          * @var \Memcached
  22          */
  23         private $memcached;
  24
  25         /**
  26          * Due to limitations of the INI format, the expected configuration for Memcached servers is the following:
  27          * array {
  28          *   0 => "hostname, port(, weight)",
  29          *   1 => ...
  30          * }
  31          *
  32          * @param array $memcached_hosts
  33          * @throws \Exception
  34          */
  35         public function __construct(array $memcached_hosts)
  36         {
  37                 if (!class_exists('Memcached', false)) {
  38                         throw new Exception('Memcached class isn\'t available');
  39                 }
  40
  41                 $this->memcached = new Memcached();
  42
  43                 array_walk($memcached_hosts, function (&$value) {
  44                         $value = array_map('trim', explode(',', $value));
  45                 });
  46
  47                 $this->memcached->addServers($memcached_hosts);
  48
  49                 if (count($this->memcached->getServerList()) == 0) {
  50                         throw new Exception('Expected Memcached servers aren\'t available, config:' . var_export($memcached_hosts, true));
  51                 }
  52         }
  53
  54         public function get($key)
  55         {
  56                 $return = null;
  57                 $cachekey = $this->getCacheKey($key);
  58
  59                 // We fetch with the hostname as key to avoid problems with other applications
  60                 $value = $this->memcached->get($cachekey);
  61
  62                 if ($this->memcached->getResultCode() === Memcached::RES_SUCCESS) {
  63                         $return = $value;
  64                 }
  65
  66                 return $return;
  67         }
  68
  69         public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
  70         {
  71                 $cachekey = $this->getCacheKey($key);
  72
  73                 // We store with the hostname as key to avoid problems with other applications
  74                 if ($ttl > 0) {
  75                         return $this->memcached->set(
  76                                 $cachekey,
  77                                 $value,
  78                                 $ttl
  79                         );
  80                 } else {
  81                         return $this->memcached->set(
  82                                 $cachekey,
  83                                 $value
  84                         );
  85                 }
  86
  87         }
  88
  89         public function delete($key)
  90         {
  91                 $cachekey = $this->getCacheKey($key);
  92                 return $this->memcached->delete($cachekey);
  93         }
  94
  95         public function clear($outdated = true)
  96         {
  97                 if ($outdated) {
  98                         return true;
  99                 } else {
 100                         return $this->memcached->flush();
 101                 }
 102         }
 103
 104         /**
 105          * @brief Sets a value if it's not already stored
 106          *
 107          * @param string $key      The cache key
 108          * @param mixed  $value    The old value we know from the cache
 109          * @param int    $ttl      The cache lifespan, must be one of the Cache constants
 110          * @return bool
 111          */
 112         public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
 113         {
 114                 $cachekey = $this->getCacheKey($key);
 115                 return $this->memcached->add($cachekey, $value, $ttl);
 116         }
 117 }