src/Core/Cache/RedisCacheDriver.php

   1 <?php
   2
   3 namespace Friendica\Core\Cache;
   4
   5 use Friendica\Core\Cache;
   6
   7 use Exception;
   8 use Redis;
   9
  10 /**
  11  * Redis Cache Driver. This driver is based on Memcache driver
  12  *
  13  * @author Hypolite Petovan <mrpetovan@gmail.com>
  14  * @author Roland Haeder <roland@mxchange.org>
  15  */
  16 class RedisCacheDriver extends AbstractCacheDriver implements IMemoryCacheDriver
  17 {
  18         /**
  19          * @var Redis
  20          */
  21         private $redis;
  22
  23         public function __construct($redis_host, $redis_port)
  24         {
  25                 if (!class_exists('Redis', false)) {
  26                         throw new Exception('Redis class isn\'t available');
  27                 }
  28
  29                 $this->redis = new Redis();
  30
  31                 if (!$this->redis->connect($redis_host, $redis_port)) {
  32                         throw new Exception('Expected Redis server at ' . $redis_host . ':' . $redis_port . ' isn\'t available');
  33                 }
  34         }
  35
  36         public function get($key)
  37         {
  38                 $return = null;
  39                 $cachekey = $this->getCacheKey($key);
  40
  41                 $cached = $this->redis->get($cachekey);
  42                 if ($cached === false && !$this->redis->exists($cachekey)) {
  43                         return null;
  44                 }
  45
  46                 $value = unserialize($cached);
  47
  48                 // Only return a value if the serialized value is valid.
  49                 // We also check if the db entry is a serialized
  50                 // boolean 'false' value (which we want to return).
  51                 if ($cached === serialize(false) || $value !== false) {
  52                         $return = $value;
  53                 }
  54
  55                 return $return;
  56         }
  57
  58         public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
  59         {
  60                 $cachekey = $this->getCacheKey($key);
  61
  62                 $cached = serialize($value);
  63
  64                 if ($ttl > 0) {
  65                         return $this->redis->setex(
  66                                 $cachekey,
  67                                 $ttl,
  68                                 $cached
  69                         );
  70                 } else {
  71                         return $this->redis->set(
  72                                 $cachekey,
  73                                 $cached
  74                         );
  75                 }
  76         }
  77
  78         public function delete($key)
  79         {
  80                 $cachekey = $this->getCacheKey($key);
  81                 return ($this->redis->delete($cachekey) > 0);
  82         }
  83
  84         public function clear($outdated = true)
  85         {
  86                 if ($outdated) {
  87                         return true;
  88                 } else {
  89                         return $this->redis->flushAll();
  90                 }
  91         }
  92
  93         /**
  94          * (@inheritdoc)
  95          */
  96         public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
  97         {
  98                 $cachekey = $this->getCacheKey($key);
  99                 $cached = serialize($value);
 100
 101                 return $this->redis->setnx($cachekey, $cached);
 102         }
 103
 104         /**
 105          * (@inheritdoc)
 106          */
 107         public function compareSet($key, $oldValue, $newValue, $ttl = Cache::FIVE_MINUTES)
 108         {
 109                 $cachekey = $this->getCacheKey($key);
 110
 111                 $newCached = serialize($newValue);
 112
 113                 $this->redis->watch($cachekey);
 114                 // If the old value isn't what we expected, somebody else changed the key meanwhile
 115                 if ($this->get($key) === $oldValue) {
 116                         if ($ttl > 0) {
 117                                 $result = $this->redis->multi()
 118                                         ->setex($cachekey, $ttl, $newCached)
 119                                         ->exec();
 120                         } else {
 121                                 $result = $this->redis->multi()
 122                                         ->set($cachekey, $newValue)
 123                                         ->exec();
 124                         }
 125                         return $result !== false;
 126                 }
 127                 $this->redis->unwatch();
 128                 return false;
 129         }
 130         /**
 131          * (@inheritdoc)
 132          */
 133         public function compareDelete($key, $value)
 134         {
 135                 $cachekey = $this->getCacheKey($key);
 136
 137                 $this->redis->watch($cachekey);
 138                 // If the old value isn't what we expected, somebody else changed the key meanwhile
 139                 if ($this->get($key) === $value) {
 140                         $result = $this->redis->multi()
 141                                 ->del($cachekey)
 142                                 ->exec();
 143                         return $result !== false;
 144                 }
 145                 $this->redis->unwatch();
 146                 return false;
 147         }
 148 }