\TYPO3\CMS\Core\DataHandling\DataHandler

public function clear_cacheCmd($cacheCmd) {
  if (is_object($this->BE_USER)) {
   $this->BE_USER->writelog(3, 1, 0, 0, 'User %s has cleared the cache (cacheCmd=%s)', array($this->BE_USER->user['username'], $cacheCmd));
  }
  // Clear cache for either ALL pages or ALL tables!
  switch (strtolower($cacheCmd)) {
   case 'pages':
    if ($this->admin || $this->BE_USER->getTSConfigVal('options.clearCache.pages')) {
     GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\Cache\\CacheManager')->flushCachesInGroup('pages');
    }
    break;
   case 'all':
    if ($this->admin || $this->BE_USER->getTSConfigVal('options.clearCache.all')) {
     // Clear cache group "all" of caching framework caches
     GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\Cache\\CacheManager')->flushCachesInGroup('all');
     $GLOBALS['TYPO3_DB']->exec_TRUNCATEquery('cache_treelist');
     // Clearing additional cache tables:
     if (is_array($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearAllCache_additionalTables'])) {
      foreach ($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearAllCache_additionalTables'] as $tableName) {
       GeneralUtility::deprecationLog('Hook clearAllCache_additionalTables in DataHandler is deprecated in 6.2 and will be removed two versions later. Use the caching framework with database backend instead.');
       if (!preg_match('/[^[:alnum:]_]/', $tableName) && substr($tableName, -5) === 'cache') {
        $GLOBALS['TYPO3_DB']->exec_TRUNCATEquery($tableName);
       } else {
        throw new \RuntimeException('TYPO3 Fatal Error: Trying to flush table "' . $tableName . '" with "Clear All Cache"', 1270853922);
       }
      }
     }
    }

    break;
   case 'temp_cached':
   case 'system':
    if ($this->admin || $this->BE_USER->getTSConfigVal('options.clearCache.system')
     || ((bool) $GLOBALS['TYPO3_CONF_VARS']['SYS']['clearCacheSystem'] === TRUE && $this->admin)) {
     GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\Cache\\CacheManager')->flushCachesInGroup('system');
    }
    break;
  }

  $tagsToFlush = array();
  // Clear cache for a page ID!
  if (\TYPO3\CMS\Core\Utility\MathUtility::canBeInterpretedAsInteger($cacheCmd)) {
   $list_cache = array($cacheCmd);
   // Call pre-processing function for clearing of cache for page ids:
   if (is_array($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearPageCacheEval'])) {
    foreach ($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearPageCacheEval'] as $funcName) {
     $_params = array('pageIdArray' => &$list_cache, 'cacheCmd' => $cacheCmd, 'functionID' => 'clear_cacheCmd()');
     // Returns the array of ids to clear, FALSE if nothing should be cleared! Never an empty array!
     GeneralUtility::callUserFunction($funcName, $_params, $this);
    }
   }
   // Delete cache for selected pages:
   if (is_array($list_cache)) {
    foreach ($list_cache as $pageId) {
     $tagsToFlush[] = 'pageId_' . (int)$pageId;
    }
   }
  }
  // flush cache by tag
  if (GeneralUtility::isFirstPartOfStr(strtolower($cacheCmd), 'cachetag:')) {
   $cacheTag = substr($cacheCmd, 9);
   $tagsToFlush[] = $cacheTag;
  }
  // process caching framwork operations
  if (count($tagsToFlush) > 0) {
   foreach (array_unique($tagsToFlush) as $tag) {
    GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\Cache\\CacheManager')->flushCachesInGroupByTag('pages', $tag);
   }
  }

  // Call post processing function for clear-cache:
  if (is_array($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearCachePostProc'])) {
   $_params = array('cacheCmd' => strtolower($cacheCmd));
   foreach ($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tcemain.php']['clearCachePostProc'] as $_funcRef) {
    GeneralUtility::callUserFunction($_funcRef, $_params, $this);
   }
  }
 }