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 (&$value) {
  44                         if (is_string($value)) {
  45                                 $value = array_map('trim', explode(',', $value));
  46                         }
  47                 });
  48
  49                 $this->memcached->addServers($memcached_hosts);
  50
  51                 if (count($this->memcached->getServerList()) == 0) {
  52                         throw new Exception('Expected Memcached servers aren\'t available, config:' . var_export($memcached_hosts, true));
  53                 }
  54         }
  55
  56         public function get($key)
  57         {
  58                 $return = null;
  59                 $cachekey = $this->getCacheKey($key);
  60
  61                 // We fetch with the hostname as key to avoid problems with other applications
  62                 $value = $this->memcached->get($cachekey);
  63
  64                 if ($this->memcached->getResultCode() === Memcached::RES_SUCCESS) {
  65                         $return = $value;
  66                 }
  67
  68                 return $return;
  69         }
  70
  71         public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
  72         {
  73                 $cachekey = $this->getCacheKey($key);
  74
  75                 // We store with the hostname as key to avoid problems with other applications
  76                 if ($ttl > 0) {
  77                         return $this->memcached->set(
  78                                 $cachekey,
  79                                 $value,
  80                                 $ttl
  81                         );
  82                 } else {
  83                         return $this->memcached->set(
  84                                 $cachekey,
  85                                 $value
  86                         );
  87                 }
  88
  89         }
  90
  91         public function delete($key)
  92         {
  93                 $cachekey = $this->getCacheKey($key);
  94                 return $this->memcached->delete($cachekey);
  95         }
  96
  97         public function clear($outdated = true)
  98         {
  99                 if ($outdated) {
 100                         return true;
 101                 } else {
 102                         return $this->memcached->flush();
 103                 }
 104         }
 105
 106         /**
 107          * @brief Sets a value if it's not already stored
 108          *
 109          * @param string $key      The cache key
 110          * @param mixed  $value    The old value we know from the cache
 111          * @param int    $ttl      The cache lifespan, must be one of the Cache constants
 112          * @return bool
 113          */
 114         public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
 115         {
 116                 $cachekey = $this->getCacheKey($key);
 117                 return $this->memcached->add($cachekey, $value, $ttl);
 118         }
 119 }