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   1  <?php
   2  /**
   3  *
   4  * This file is part of the phpBB Forum Software package.
   5  *
   6  * @copyright (c) phpBB Limited <https://www.phpbb.com>
   7  * @license GNU General Public License, version 2 (GPL-2.0)
   8  *
   9  * For full copyright and license information, please see
  10  * the docs/CREDITS.txt file.
  11  *
  12  */
  13  
  14  namespace phpbb\cache\driver;
  15  
  16  /**
  17  * ACM Abstract Memory Class
  18  */
  19  abstract class memory extends \phpbb\cache\driver\base
  20  {
  21      var $key_prefix;
  22  
  23      /**
  24      * Set cache path
  25      */
  26  	function __construct()
  27      {
  28          global $phpbb_root_path, $dbname, $table_prefix;
  29  
  30          $this->cache_dir    = $phpbb_root_path . 'cache/';
  31          $this->key_prefix    = substr(md5($dbname . $table_prefix), 0, 8) . '_';
  32  
  33          if (!isset($this->extension) || !extension_loaded($this->extension))
  34          {
  35              global $acm_type;
  36  
  37              trigger_error("Could not find required extension [{$this->extension}] for the ACM module $acm_type.", E_USER_ERROR);
  38          }
  39  
  40          if (isset($this->function) && !function_exists($this->function))
  41          {
  42              global $acm_type;
  43  
  44              trigger_error("The required function [{$this->function}] is not available for the ACM module $acm_type.", E_USER_ERROR);
  45          }
  46      }
  47  
  48      /**
  49      * {@inheritDoc}
  50      */
  51  	function load()
  52      {
  53          // grab the global cache
  54          $this->vars = $this->_read('global');
  55  
  56          if ($this->vars !== false)
  57          {
  58              return true;
  59          }
  60  
  61          return false;
  62      }
  63  
  64      /**
  65      * {@inheritDoc}
  66      */
  67  	function save()
  68      {
  69          if (!$this->is_modified)
  70          {
  71              return;
  72          }
  73  
  74          $this->_write('global', $this->vars, 2592000);
  75  
  76          $this->is_modified = false;
  77      }
  78  
  79      /**
  80      * {@inheritDoc}
  81      */
  82  	function tidy()
  83      {
  84          // cache has auto GC, no need to have any code here :)
  85  
  86          set_config('cache_last_gc', time(), true);
  87      }
  88  
  89      /**
  90      * {@inheritDoc}
  91      */
  92  	function get($var_name)
  93      {
  94          if ($var_name[0] == '_')
  95          {
  96              if (!$this->_exists($var_name))
  97              {
  98                  return false;
  99              }
 100  
 101              return $this->_read($var_name);
 102          }
 103          else
 104          {
 105              return ($this->_exists($var_name)) ? $this->vars[$var_name] : false;
 106          }
 107      }
 108  
 109      /**
 110      * {@inheritDoc}
 111      */
 112  	function put($var_name, $var, $ttl = 2592000)
 113      {
 114          if ($var_name[0] == '_')
 115          {
 116              $this->_write($var_name, $var, $ttl);
 117          }
 118          else
 119          {
 120              $this->vars[$var_name] = $var;
 121              $this->is_modified = true;
 122          }
 123      }
 124  
 125      /**
 126      * {@inheritDoc}
 127      */
 128  	function destroy($var_name, $table = '')
 129      {
 130          if ($var_name == 'sql' && !empty($table))
 131          {
 132              if (!is_array($table))
 133              {
 134                  $table = array($table);
 135              }
 136  
 137              foreach ($table as $table_name)
 138              {
 139                  // gives us the md5s that we want
 140                  $temp = $this->_read('sql_' . $table_name);
 141  
 142                  if ($temp === false)
 143                  {
 144                      continue;
 145                  }
 146  
 147                  // delete each query ref
 148                  foreach ($temp as $md5_id => $void)
 149                  {
 150                      $this->_delete('sql_' . $md5_id);
 151                  }
 152  
 153                  // delete the table ref
 154                  $this->_delete('sql_' . $table_name);
 155              }
 156  
 157              return;
 158          }
 159  
 160          if (!$this->_exists($var_name))
 161          {
 162              return;
 163          }
 164  
 165          if ($var_name[0] == '_')
 166          {
 167              $this->_delete($var_name);
 168          }
 169          else if (isset($this->vars[$var_name]))
 170          {
 171              $this->is_modified = true;
 172              unset($this->vars[$var_name]);
 173  
 174              // We save here to let the following cache hits succeed
 175              $this->save();
 176          }
 177      }
 178  
 179      /**
 180      * {@inheritDoc}
 181      */
 182  	function _exists($var_name)
 183      {
 184          if ($var_name[0] == '_')
 185          {
 186              return $this->_isset($var_name);
 187          }
 188          else
 189          {
 190              if (!sizeof($this->vars))
 191              {
 192                  $this->load();
 193              }
 194  
 195              return isset($this->vars[$var_name]);
 196          }
 197      }
 198  
 199      /**
 200      * {@inheritDoc}
 201      */
 202  	function sql_save(\phpbb\db\driver\driver_interface $db, $query, $query_result, $ttl)
 203      {
 204          // Remove extra spaces and tabs
 205          $query = preg_replace('/[\n\r\s\t]+/', ' ', $query);
 206          $hash = md5($query);
 207  
 208          // determine which tables this query belongs to
 209          // Some queries use backticks, namely the get_database_size() query
 210          // don't check for conformity, the SQL would error and not reach here.
 211          if (!preg_match_all('/(?:FROM \\(?(`?\\w+`?(?: \\w+)?(?:, ?`?\\w+`?(?: \\w+)?)*)\\)?)|(?:JOIN (`?\\w+`?(?: \\w+)?))/', $query, $regs, PREG_SET_ORDER))
 212          {
 213              // Bail out if the match fails.
 214              return $query_result;
 215          }
 216  
 217          $tables = array();
 218          foreach ($regs as $match)
 219          {
 220              if ($match[0][0] == 'F')
 221              {
 222                  $tables = array_merge($tables, array_map('trim', explode(',', $match[1])));
 223              }
 224              else
 225              {
 226                  $tables[] = $match[2];
 227              }
 228          }
 229  
 230          foreach ($tables as $table_name)
 231          {
 232              // Remove backticks
 233              $table_name = ($table_name[0] == '`') ? substr($table_name, 1, -1) : $table_name;
 234  
 235              if (($pos = strpos($table_name, ' ')) !== false)
 236              {
 237                  $table_name = substr($table_name, 0, $pos);
 238              }
 239  
 240              $temp = $this->_read('sql_' . $table_name);
 241  
 242              if ($temp === false)
 243              {
 244                  $temp = array();
 245              }
 246  
 247              $temp[$hash] = true;
 248  
 249              // This must never expire
 250              $this->_write('sql_' . $table_name, $temp, 0);
 251          }
 252  
 253          // store them in the right place
 254          $query_id = sizeof($this->sql_rowset);
 255          $this->sql_rowset[$query_id] = array();
 256          $this->sql_row_pointer[$query_id] = 0;
 257  
 258          while ($row = $db->sql_fetchrow($query_result))
 259          {
 260              $this->sql_rowset[$query_id][] = $row;
 261          }
 262          $db->sql_freeresult($query_result);
 263  
 264          $this->_write('sql_' . $hash, $this->sql_rowset[$query_id], $ttl);
 265  
 266          return $query_id;
 267      }
 268  
 269      /**
 270      * Check if a cache var exists
 271      *
 272      * @access protected
 273      * @param string $var Cache key
 274      * @return bool True if it exists, otherwise false
 275      */
 276  	function _isset($var)
 277      {
 278          // Most caches don't need to check
 279          return true;
 280      }
 281  }