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