include/cache.php

   1 <?php
   2 /**
   3  * @file include/cache.php
   4  *
   5  * @brief Class for storing data for a short time
   6  */
   7
   8 use \Friendica\Core\Config;
   9 use \Friendica\Core\PConfig;
  10
  11 class Cache {
  12         /**
  13          * @brief Check for memcache and open a connection if configured
  14          *
  15          * @return object|boolean The memcache object - or "false" if not successful
  16          */
  17         public static function memcache() {
  18                 if (!function_exists('memcache_connect')) {
  19                         return false;
  20                 }
  21
  22                 if (!Config::get('system', 'memcache')) {
  23                         return false;
  24                 }
  25
  26                 $memcache_host = Config::get('system', 'memcache_host', '127.0.0.1');
  27                 $memcache_port = Config::get('system', 'memcache_port', 11211);
  28
  29                 $memcache = new Memcache;
  30
  31                 if (!$memcache->connect($memcache_host, $memcache_port)) {
  32                         return false;
  33                 }
  34
  35                 return $memcache;
  36         }
  37
  38         /**
  39          * @brief Return the duration for a given cache level
  40          *
  41          * @param integer $level Cache level
  42          *
  43          * @return integer The cache duration in seconds
  44          */
  45         private function duration($level) {
  46                 switch($level) {
  47                         case CACHE_MONTH;
  48                                 $seconds = 2592000;
  49                                 break;
  50                         case CACHE_WEEK;
  51                                 $seconds = 604800;
  52                                 break;
  53                         case CACHE_DAY;
  54                                 $seconds = 86400;
  55                                 break;
  56                         case CACHE_HOUR;
  57                                 $seconds = 3600;
  58                                 break;
  59                         case CACHE_HALF_HOUR;
  60                                 $seconds = 1800;
  61                                 break;
  62                         case CACHE_QUARTER_HOUR;
  63                                 $seconds = 900;
  64                                 break;
  65                         case CACHE_FIVE_MINUTES;
  66                                 $seconds = 300;
  67                                 break;
  68                         case CACHE_MINUTE;
  69                                 $seconds = 60;
  70                                 break;
  71                 }
  72                 return $seconds;
  73         }
  74
  75         /**
  76          * @brief Fetch cached data according to the key
  77          *
  78          * @param string $key The key to the cached data
  79          *
  80          * @return mixed Cached $value or "null" if not found
  81          */
  82         public static function get($key) {
  83
  84                 $memcache = self::memcache();
  85                 if (is_object($memcache)) {
  86                         // We fetch with the hostname as key to avoid problems with other applications
  87                         $value = $memcache->get(get_app()->get_hostname().":".$key);
  88                         if (!is_bool($value)) {
  89                                 return unserialize($value);
  90                         }
  91
  92                         return null;
  93                 }
  94
  95                 // Frequently clear cache
  96                 self::clear($duration);
  97
  98                 $r = q("SELECT `v` FROM `cache` WHERE `k`='%s' LIMIT 1",
  99                         dbesc($key)
 100                 );
 101
 102                 if (count($r)) {
 103                         return $r[0]['v'];
 104                 }
 105
 106                 return null;
 107         }
 108
 109         /**
 110          * @brief Put data in the cache according to the key
 111          *
 112          * @param string $key The key to the cached data
 113          * @param mixed $valie The value that is about to be stored
 114          * @param integer $duration The cache lifespan
 115          */
 116         public static function set($key, $value, $duration = CACHE_MONTH) {
 117
 118                 // Do we have an installed memcache? Use it instead.
 119                 $memcache = self::memcache();
 120                 if (is_object($memcache)) {
 121                         // We store with the hostname as key to avoid problems with other applications
 122                         $memcache->set(get_app()->get_hostname().":".$key, serialize($value), MEMCACHE_COMPRESSED, self::duration($duration));
 123                         return;
 124                 }
 125
 126                 /// @todo store the cache data in the same way like the config data
 127                 q("REPLACE INTO `cache` (`k`,`v`,`expire_mode`,`updated`) VALUES ('%s','%s',%d,'%s')",
 128                                 dbesc($key),
 129                                 dbesc($value),
 130                                 intval($duration),
 131                                 dbesc(datetime_convert()));
 132         }
 133
 134         /**
 135          * @brief Remove outdated data from the cache
 136          *
 137          * @param integer $maxlevel The maximum cache level that is to be cleared
 138          */
 139         public static function clear($max_level = CACHE_MONTH) {
 140
 141                 // Clear long lasting cache entries only once a day
 142                 if (get_config("system", "cache_cleared_day") < time() - self::duration(CACHE_DAY)) {
 143                         if ($max_level == CACHE_MONTH) {
 144                                 q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 145                                         dbesc(datetime_convert('UTC','UTC',"now - 30 days")), intval(CACHE_MONTH));
 146                         }
 147
 148                         if ($max_level <= CACHE_WEEK) {
 149                                 q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 150                                         dbesc(datetime_convert('UTC','UTC',"now - 7 days")), intval(CACHE_WEEK));
 151                         }
 152
 153                         if ($max_level <= CACHE_DAY) {
 154                                 q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 155                                 dbesc(datetime_convert('UTC','UTC',"now - 1 days")), intval(CACHE_DAY));
 156                         }
 157                         set_config("system", "cache_cleared_day", time());
 158                 }
 159
 160                 if (($max_level <= CACHE_HOUR) AND (get_config("system", "cache_cleared_hour")) < time() - self::duration(CACHE_HOUR)) {
 161                         q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 162                                 dbesc(datetime_convert('UTC','UTC',"now - 1 hours")), intval(CACHE_HOUR));
 163
 164                         set_config("system", "cache_cleared_hour", time());
 165                 }
 166
 167                 if (($max_level <= CACHE_HALF_HOUR) AND (get_config("system", "cache_cleared_half_hour")) < time() - self::duration(CACHE_HALF_HOUR)) {
 168                         q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 169                                 dbesc(datetime_convert('UTC','UTC',"now - 30 minutes")), intval(CACHE_HALF_HOUR));
 170
 171                         set_config("system", "cache_cleared_half_hour", time());
 172                 }
 173
 174                 if (($max_level <= CACHE_QUARTER_HOUR) AND (get_config("system", "cache_cleared_hour")) < time() - self::duration(CACHE_QUARTER_HOUR)) {
 175                         q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 176                                 dbesc(datetime_convert('UTC','UTC',"now - 15 minutes")), intval(CACHE_QUARTER_HOUR));
 177
 178                         set_config("system", "cache_cleared_quarter_hour", time());
 179                 }
 180
 181                 if (($max_level <= CACHE_FIVE_MINUTES) AND (get_config("system", "cache_cleared_five_minute")) < time() - self::duration(CACHE_FIVE_MINUTES)) {
 182                         q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 183                                 dbesc(datetime_convert('UTC','UTC',"now - 5 minutes")), intval(CACHE_FIVE_MINUTES));
 184
 185                         set_config("system", "cache_cleared_five_minute", time());
 186                 }
 187
 188                 if (($max_level <= CACHE_MINUTE) AND (get_config("system", "cache_cleared_minute")) < time() - self::duration(CACHE_MINUTE)) {
 189                         q("DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 190                                 dbesc(datetime_convert('UTC','UTC',"now - 1 minutes")), intval(CACHE_MINUTE));
 191
 192                         set_config("system", "cache_cleared_minute", time());
 193                 }
 194         }
 195 }