src/Core/Cache.php

   1 <?php
   2 /**
   3  * @file src/Core/Cache.php
   4  */
   5 namespace Friendica\Core;
   6
   7 use Friendica\Core\Config;
   8 use Friendica\Core\PConfig;
   9 use Friendica\Database\DBM;
  10
  11 /**
  12  * @brief Class for storing data for a short time
  13  */
  14 class Cache
  15 {
  16         /**
  17          * @brief Check for memcache and open a connection if configured
  18          *
  19          * @return object|boolean The memcache object - or "false" if not successful
  20          */
  21         public static function memcache()
  22         {
  23                 if (!function_exists('memcache_connect')) {
  24                         return false;
  25                 }
  26
  27                 if (!Config::get('system', 'memcache')) {
  28                         return false;
  29                 }
  30
  31                 $memcache_host = Config::get('system', 'memcache_host', '127.0.0.1');
  32                 $memcache_port = Config::get('system', 'memcache_port', 11211);
  33
  34                 $memcache = new Memcache;
  35
  36                 if (!$memcache->connect($memcache_host, $memcache_port)) {
  37                         return false;
  38                 }
  39
  40                 return $memcache;
  41         }
  42
  43         /**
  44          * @brief Return the duration for a given cache level
  45          *
  46          * @param integer $level Cache level
  47          *
  48          * @return integer The cache duration in seconds
  49          */
  50         private static function duration($level)
  51         {
  52                 switch ($level) {
  53                         case CACHE_MONTH:
  54                                 $seconds = 2592000;
  55                                 break;
  56                         case CACHE_WEEK:
  57                                 $seconds = 604800;
  58                                 break;
  59                         case CACHE_DAY:
  60                                 $seconds = 86400;
  61                                 break;
  62                         case CACHE_HOUR:
  63                                 $seconds = 3600;
  64                                 break;
  65                         case CACHE_HALF_HOUR:
  66                                 $seconds = 1800;
  67                                 break;
  68                         case CACHE_QUARTER_HOUR:
  69                                 $seconds = 900;
  70                                 break;
  71                         case CACHE_FIVE_MINUTES:
  72                                 $seconds = 300;
  73                                 break;
  74                         case CACHE_MINUTE:
  75                                 $seconds = 60;
  76                                 break;
  77                 }
  78                 return $seconds;
  79         }
  80
  81         /**
  82          * @brief Fetch cached data according to the key
  83          *
  84          * @param string $key The key to the cached data
  85          *
  86          * @return mixed Cached $value or "null" if not found
  87          */
  88         public static function get($key)
  89         {
  90                 $memcache = self::memcache();
  91                 if (is_object($memcache)) {
  92                         // We fetch with the hostname as key to avoid problems with other applications
  93                         $cached = $memcache->get(get_app()->get_hostname().":".$key);
  94                         $value = @unserialize($cached);
  95
  96                         // Only return a value if the serialized value is valid.
  97                         // We also check if the db entry is a serialized
  98                         // boolean 'false' value (which we want to return).
  99                         if ($cached === serialize(false) || $value !== false) {
 100                                 return $value;
 101                         }
 102
 103                         return null;
 104                 }
 105
 106                 // Frequently clear cache
 107                 self::clear($duration);
 108
 109                 $r = q(
 110                         "SELECT `v` FROM `cache` WHERE `k`='%s' LIMIT 1",
 111                         dbesc($key)
 112                 );
 113
 114                 if (DBM::is_result($r)) {
 115                         $cached = $r[0]['v'];
 116                         $value = @unserialize($cached);
 117
 118                         // Only return a value if the serialized value is valid.
 119                         // We also check if the db entry is a serialized
 120                         // boolean 'false' value (which we want to return).
 121                         if ($cached === serialize(false) || $value !== false) {
 122                                 return $value;
 123                         }
 124                 }
 125
 126                 return null;
 127         }
 128
 129         /**
 130          * @brief Put data in the cache according to the key
 131          *
 132          * The input $value can have multiple formats.
 133          *
 134          * @param string  $key      The key to the cached data
 135          * @param mixed   $value    The value that is about to be stored
 136          * @param integer $duration The cache lifespan
 137          */
 138         public static function set($key, $value, $duration = CACHE_MONTH)
 139         {
 140                 // Do we have an installed memcache? Use it instead.
 141                 $memcache = self::memcache();
 142                 if (is_object($memcache)) {
 143                         // We store with the hostname as key to avoid problems with other applications
 144                         $memcache->set(get_app()->get_hostname().":".$key, serialize($value), MEMCACHE_COMPRESSED, self::duration($duration));
 145                         return;
 146                 }
 147
 148                 /// @todo store the cache data in the same way like the config data
 149                 q(
 150                         "REPLACE INTO `cache` (`k`,`v`,`expire_mode`,`updated`) VALUES ('%s','%s',%d,'%s')",
 151                         dbesc($key),
 152                         dbesc(serialize($value)),
 153                         intval($duration),
 154                         dbesc(datetime_convert())
 155                 );
 156         }
 157
 158         /**
 159          * @brief Remove outdated data from the cache
 160          *
 161          * @param integer $max_level The maximum cache level that is to be cleared
 162          */
 163         public static function clear($max_level = CACHE_MONTH)
 164         {
 165                 // Clear long lasting cache entries only once a day
 166                 if (Config::get("system", "cache_cleared_day") < time() - self::duration(CACHE_DAY)) {
 167                         if ($max_level == CACHE_MONTH) {
 168                                 q(
 169                                         "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 170                                         dbesc(datetime_convert('UTC', 'UTC', "now - 30 days")),
 171                                         intval(CACHE_MONTH)
 172                                 );
 173                         }
 174
 175                         if ($max_level <= CACHE_WEEK) {
 176                                 q(
 177                                         "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 178                                         dbesc(datetime_convert('UTC', 'UTC', "now - 7 days")),
 179                                         intval(CACHE_WEEK)
 180                                 );
 181                         }
 182
 183                         if ($max_level <= CACHE_DAY) {
 184                                 q(
 185                                         "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 186                                         dbesc(datetime_convert('UTC', 'UTC', "now - 1 days")),
 187                                         intval(CACHE_DAY)
 188                                 );
 189                         }
 190                         Config::set("system", "cache_cleared_day", time());
 191                 }
 192
 193                 if (($max_level <= CACHE_HOUR) && (Config::get("system", "cache_cleared_hour")) < time() - self::duration(CACHE_HOUR)) {
 194                         q(
 195                                 "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 196                                 dbesc(datetime_convert('UTC', 'UTC', "now - 1 hours")),
 197                                 intval(CACHE_HOUR)
 198                         );
 199
 200                         Config::set("system", "cache_cleared_hour", time());
 201                 }
 202
 203                 if (($max_level <= CACHE_HALF_HOUR) && (Config::get("system", "cache_cleared_half_hour")) < time() - self::duration(CACHE_HALF_HOUR)) {
 204                         q(
 205                                 "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 206                                 dbesc(datetime_convert('UTC', 'UTC', "now - 30 minutes")),
 207                                 intval(CACHE_HALF_HOUR)
 208                         );
 209
 210                         Config::set("system", "cache_cleared_half_hour", time());
 211                 }
 212
 213                 if (($max_level <= CACHE_QUARTER_HOUR) && (Config::get("system", "cache_cleared_quarter_hour")) < time() - self::duration(CACHE_QUARTER_HOUR)) {
 214                         q(
 215                                 "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 216                                 dbesc(datetime_convert('UTC', 'UTC', "now - 15 minutes")),
 217                                 intval(CACHE_QUARTER_HOUR)
 218                         );
 219
 220                         Config::set("system", "cache_cleared_quarter_hour", time());
 221                 }
 222
 223                 if (($max_level <= CACHE_FIVE_MINUTES) && (Config::get("system", "cache_cleared_five_minute")) < time() - self::duration(CACHE_FIVE_MINUTES)) {
 224                         q(
 225                                 "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 226                                 dbesc(datetime_convert('UTC', 'UTC', "now - 5 minutes")),
 227                                 intval(CACHE_FIVE_MINUTES)
 228                         );
 229
 230                         Config::set("system", "cache_cleared_five_minute", time());
 231                 }
 232
 233                 if (($max_level <= CACHE_MINUTE) && (Config::get("system", "cache_cleared_minute")) < time() - self::duration(CACHE_MINUTE)) {
 234                         q(
 235                                 "DELETE FROM `cache` WHERE `updated` < '%s' AND `expire_mode` = %d",
 236                                 dbesc(datetime_convert('UTC', 'UTC', "now - 1 minutes")),
 237                                 intval(CACHE_MINUTE)
 238                         );
 239
 240                         Config::set("system", "cache_cleared_minute", time());
 241                 }
 242         }
 243 }