public static function createCacheRandWords(array $condition = array(), $expired = 24)
 {
     ini_set('memory_limit', '512M');
     $return_pagenum_list = array();
     $expired = $expired * 3600;
     //一天
     $pagenum_expired = 2 * $expired;
     //两天
     $file_cache = \Yii::$app->cache_data_file;
     $cache_key_letter_pagenum = sprintf('$s|%s|%s|%s', 'disease_words', 'caches', 'randwords', 'pagenum');
     $cache_letter_pagenum_data = $file_cache->get($cache_key_letter_pagenum);
     if ($cache_letter_pagenum_data) {
         $return_pagenum_list = $cache_letter_pagenum_data;
     }
     //获取字母所对应的数据
     $letter_list = 'abcdefghijklmnopqrstuvwxyz';
     $len = strlen($letter_list);
     $return_list = array();
     $max_kw_length = 2500;
     // $size;
     for ($i = 0; $i < $len; $i++) {
         $wd = strtoupper($letter_list[$i]);
         $pagenum = isset($return_pagenum_list[$wd]) ? $return_pagenum_list[$wd] : 0;
         $pagenum = intval($pagenum) + 1;
         $tmp_offset = $pagenum * $max_kw_length;
         $return_info = Search::search_disease_symptom_words_byinitial($wd, $tmp_offset, $max_kw_length, $condition);
         if (count($return_info['list']) == 0 && $pagenum > 0) {
             $return_info = Search::search_disease_symptom_words_byinitial($wd, 0, $max_kw_length, $condition);
             $pagenum = 0;
         }
         $ret = $return_info['list'];
         $return_list[$wd] = $ret;
         $return_pagenum_list[$wd] = $pagenum;
     }
     self::createRandWordsForRedis($return_list);
     $cache_key_letter_words = sprintf('$s|%s|%s|%s', 'disease_words', 'caches', 'randwords', 'words');
     $file_cache->set($cache_key_letter_words, $return_list, $expired);
     $file_cache->set($cache_key_letter_pagenum, $return_pagenum_list, $pagenum_expired);
     return $return_list;
 }