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   1  <?php
   2  /**
   3  *
   4  * @package acm
   5  * @version $Id$
   6  * @copyright (c) 2005 phpBB Group
   7  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
   8  *
   9  */
  10  
  11  /**
  12  * @ignore
  13  */
  14  if (!defined('IN_PHPBB'))
  15  {
  16      exit;
  17  }
  18  
  19  /**
  20  * ACM Abstract Memory Class
  21  * @package acm
  22  */
  23  class acm_memory
  24  {
  25      var $key_prefix;
  26  
  27      var $vars = array();
  28      var $is_modified = false;
  29  
  30      var $sql_rowset = array();
  31      var $sql_row_pointer = array();
  32      var $cache_dir = '';
  33  
  34      /**
  35      * Set cache path
  36      */
  37  	function acm_memory()
  38      {
  39          global $phpbb_root_path, $dbname, $table_prefix;
  40  
  41          $this->cache_dir    = $phpbb_root_path . 'cache/';
  42          $this->key_prefix    = substr(md5($dbname . $table_prefix), 0, 8) . '_';
  43  
  44          if (!isset($this->extension) || !extension_loaded($this->extension))
  45          {
  46              global $acm_type;
  47  
  48              trigger_error("Could not find required extension [{$this->extension}] for the ACM module $acm_type.", E_USER_ERROR);
  49          }
  50  
  51          if (isset($this->function) && !function_exists($this->function))
  52          {
  53              global $acm_type;
  54  
  55              trigger_error("The required function [{$this->function}] is not available for the ACM module $acm_type.", E_USER_ERROR);
  56          }
  57      }
  58  
  59      /**
  60      * Load global cache
  61      */
  62  	function load()
  63      {
  64          // grab the global cache
  65          $this->vars = $this->_read('global');
  66  
  67          if ($this->vars !== false)
  68          {
  69              return true;
  70          }
  71  
  72          return false;
  73      }
  74  
  75      /**
  76      * Unload cache object
  77      */
  78  	function unload()
  79      {
  80          $this->save();
  81          unset($this->vars);
  82          unset($this->sql_rowset);
  83          unset($this->sql_row_pointer);
  84  
  85          $this->vars = array();
  86          $this->sql_rowset = array();
  87          $this->sql_row_pointer = array();
  88      }
  89  
  90      /**
  91      * Save modified objects
  92      */
  93  	function save()
  94      {
  95          if (!$this->is_modified)
  96          {
  97              return;
  98          }
  99  
 100          $this->_write('global', $this->vars, 2592000);
 101  
 102          $this->is_modified = false;
 103      }
 104  
 105      /**
 106      * Tidy cache
 107      */
 108  	function tidy()
 109      {
 110          // cache has auto GC, no need to have any code here :)
 111  
 112          set_config('cache_last_gc', time(), true);
 113      }
 114  
 115      /**
 116      * Get saved cache object
 117      */
 118  	function get($var_name)
 119      {
 120          if ($var_name[0] == '_')
 121          {
 122              if (!$this->_exists($var_name))
 123              {
 124                  return false;
 125              }
 126  
 127              return $this->_read($var_name);
 128          }
 129          else
 130          {
 131              return ($this->_exists($var_name)) ? $this->vars[$var_name] : false;
 132          }
 133      }
 134  
 135      /**
 136      * Put data into cache
 137      */
 138  	function put($var_name, $var, $ttl = 2592000)
 139      {
 140          if ($var_name[0] == '_')
 141          {
 142              $this->_write($var_name, $var, $ttl);
 143          }
 144          else
 145          {
 146              $this->vars[$var_name] = $var;
 147              $this->is_modified = true;
 148          }
 149      }
 150  
 151      /**
 152      * Purge cache data
 153      */
 154  	function purge()
 155      {
 156          // Purge all phpbb cache files
 157          $dir = @opendir($this->cache_dir);
 158  
 159          if (!$dir)
 160          {
 161              return;
 162          }
 163  
 164          while (($entry = readdir($dir)) !== false)
 165          {
 166              if (strpos($entry, 'sql_') !== 0 && strpos($entry, 'data_') !== 0 && strpos($entry, 'ctpl_') !== 0 && strpos($entry, 'tpl_') !== 0)
 167              {
 168                  continue;
 169              }
 170  
 171              $this->remove_file($this->cache_dir . $entry);
 172          }
 173          closedir($dir);
 174  
 175          unset($this->vars);
 176          unset($this->sql_rowset);
 177          unset($this->sql_row_pointer);
 178  
 179          $this->vars = array();
 180          $this->sql_rowset = array();
 181          $this->sql_row_pointer = array();
 182  
 183          $this->is_modified = false;
 184      }
 185  
 186  
 187      /**
 188      * Destroy cache data
 189      */
 190  	function destroy($var_name, $table = '')
 191      {
 192          if ($var_name == 'sql' && !empty($table))
 193          {
 194              if (!is_array($table))
 195              {
 196                  $table = array($table);
 197              }
 198  
 199              foreach ($table as $table_name)
 200              {
 201                  // gives us the md5s that we want
 202                  $temp = $this->_read('sql_' . $table_name);
 203  
 204                  if ($temp === false)
 205                  {
 206                      continue;
 207                  }
 208  
 209                  // delete each query ref
 210                  foreach ($temp as $md5_id => $void)
 211                  {
 212                      $this->_delete('sql_' . $md5_id);
 213                  }
 214  
 215                  // delete the table ref
 216                  $this->_delete('sql_' . $table_name);
 217              }
 218  
 219              return;
 220          }
 221  
 222          if (!$this->_exists($var_name))
 223          {
 224              return;
 225          }
 226  
 227          if ($var_name[0] == '_')
 228          {
 229              $this->_delete($var_name);
 230          }
 231          else if (isset($this->vars[$var_name]))
 232          {
 233              $this->is_modified = true;
 234              unset($this->vars[$var_name]);
 235  
 236              // We save here to let the following cache hits succeed
 237              $this->save();
 238          }
 239      }
 240  
 241      /**
 242      * Check if a given cache entry exist
 243      */
 244  	function _exists($var_name)
 245      {
 246          if ($var_name[0] == '_')
 247          {
 248              return $this->_isset($var_name);
 249          }
 250          else
 251          {
 252              if (!sizeof($this->vars))
 253              {
 254                  $this->load();
 255              }
 256  
 257              return isset($this->vars[$var_name]);
 258          }
 259      }
 260  
 261      /**
 262      * Load cached sql query
 263      */
 264  	function sql_load($query)
 265      {
 266          // Remove extra spaces and tabs
 267          $query = preg_replace('/[\n\r\s\t]+/', ' ', $query);
 268          $query_id = sizeof($this->sql_rowset);
 269  
 270          if (($result = $this->_read('sql_' . md5($query))) === false)
 271          {
 272              return false;
 273          }
 274  
 275          $this->sql_rowset[$query_id] = $result;
 276          $this->sql_row_pointer[$query_id] = 0;
 277  
 278          return $query_id;
 279      }
 280  
 281      /**
 282      * Save sql query
 283      */
 284  	function sql_save($query, &$query_result, $ttl)
 285      {
 286          global $db;
 287  
 288          // Remove extra spaces and tabs
 289          $query = preg_replace('/[\n\r\s\t]+/', ' ', $query);
 290          $hash = md5($query);
 291  
 292          // determine which tables this query belongs to
 293          // Some queries use backticks, namely the get_database_size() query
 294          // don't check for conformity, the SQL would error and not reach here.
 295          if (!preg_match('/FROM \\(?(`?\\w+`?(?: \\w+)?(?:, ?`?\\w+`?(?: \\w+)?)*)\\)?/', $query, $regs))
 296          {
 297              // Bail out if the match fails.
 298              return;
 299          }
 300          $tables = array_map('trim', explode(',', $regs[1]));
 301  
 302          foreach ($tables as $table_name)
 303          {
 304              // Remove backticks
 305              $table_name = ($table_name[0] == '`') ? substr($table_name, 1, -1) : $table_name;
 306  
 307              if (($pos = strpos($table_name, ' ')) !== false)
 308              {
 309                  $table_name = substr($table_name, 0, $pos);
 310              }
 311  
 312              $temp = $this->_read('sql_' . $table_name);
 313  
 314              if ($temp === false)
 315              {
 316                  $temp = array();
 317              }
 318  
 319              $temp[$hash] = true;
 320  
 321              // This must never expire
 322              $this->_write('sql_' . $table_name, $temp, 0);
 323          }
 324  
 325          // store them in the right place
 326          $query_id = sizeof($this->sql_rowset);
 327          $this->sql_rowset[$query_id] = array();
 328          $this->sql_row_pointer[$query_id] = 0;
 329  
 330          while ($row = $db->sql_fetchrow($query_result))
 331          {
 332              $this->sql_rowset[$query_id][] = $row;
 333          }
 334          $db->sql_freeresult($query_result);
 335  
 336          $this->_write('sql_' . $hash, $this->sql_rowset[$query_id], $ttl);
 337  
 338          $query_result = $query_id;
 339      }
 340  
 341      /**
 342      * Ceck if a given sql query exist in cache
 343      */
 344  	function sql_exists($query_id)
 345      {
 346          return isset($this->sql_rowset[$query_id]);
 347      }
 348  
 349      /**
 350      * Fetch row from cache (database)
 351      */
 352  	function sql_fetchrow($query_id)
 353      {
 354          if ($this->sql_row_pointer[$query_id] < sizeof($this->sql_rowset[$query_id]))
 355          {
 356              return $this->sql_rowset[$query_id][$this->sql_row_pointer[$query_id]++];
 357          }
 358  
 359          return false;
 360      }
 361  
 362      /**
 363      * Fetch a field from the current row of a cached database result (database)
 364      */
 365  	function sql_fetchfield($query_id, $field)
 366      {
 367          if ($this->sql_row_pointer[$query_id] < sizeof($this->sql_rowset[$query_id]))
 368          {
 369              return (isset($this->sql_rowset[$query_id][$this->sql_row_pointer[$query_id]][$field])) ? $this->sql_rowset[$query_id][$this->sql_row_pointer[$query_id]++][$field] : false;
 370          }
 371  
 372          return false;
 373      }
 374  
 375      /**
 376      * Seek a specific row in an a cached database result (database)
 377      */
 378  	function sql_rowseek($rownum, $query_id)
 379      {
 380          if ($rownum >= sizeof($this->sql_rowset[$query_id]))
 381          {
 382              return false;
 383          }
 384  
 385          $this->sql_row_pointer[$query_id] = $rownum;
 386          return true;
 387      }
 388  
 389      /**
 390      * Free memory used for a cached database result (database)
 391      */
 392  	function sql_freeresult($query_id)
 393      {
 394          if (!isset($this->sql_rowset[$query_id]))
 395          {
 396              return false;
 397          }
 398  
 399          unset($this->sql_rowset[$query_id]);
 400          unset($this->sql_row_pointer[$query_id]);
 401  
 402          return true;
 403      }
 404  
 405      /**
 406      * Removes/unlinks file
 407      */
 408  	function remove_file($filename, $check = false)
 409      {
 410          if (!function_exists('phpbb_is_writable'))
 411          {
 412              global $phpbb_root_path, $phpEx;
 413              include($phpbb_root_path . 'includes/functions.' . $phpEx);
 414          }
 415  
 416          if ($check && !phpbb_is_writable($this->cache_dir))
 417          {
 418              // E_USER_ERROR - not using language entry - intended.
 419              trigger_error('Unable to remove files within ' . $this->cache_dir . '. Please check directory permissions.', E_USER_ERROR);
 420          }
 421  
 422          return @unlink($filename);
 423      }
 424  
 425      /**
 426      * Check if a cache var exists
 427      *
 428      * @access protected
 429      * @param string $var Cache key
 430      * @return bool True if it exists, otherwise false
 431      */
 432  	function _isset($var)
 433      {
 434          // Most caches don't need to check
 435          return true;
 436      }
 437  }
 438  
 439  ?>