读取 mysql binlog 开始和结束时间(2)

            'server_id' => 'l',
            'event_length' => 'l',
            'next_position' => 'l',
            'flags' => 's',
        );
        return $this->toPackStr($event_header_struct);
    }
 
    protected function formatDescriptionEventDataPackStr() {
        $format_description_event_data_struct = array(
            'binlog_version' => 's',
            'server_version' => 'a50',
            'create_timestamp' => 'l',
            'head_length' => 'c'
        );
        return $this->toPackStr($format_description_event_data_struct);
    }
 
    protected function toPackStr($arr) {
        $ret = '';
        foreach ($arr as $k=>$v) {
            $ret.= '/'.$v.$k;
        }
        $ret = substr($ret, 1);
        return $ret;
    }
 
    /**
     * @param resource $file
     *
     * Mysql binlog file begin with a 4 bytes head: "\xfebin".
     */
    protected function isBinlog($file) {
        rewind($file);
        $head = fread($file, strlen(self::BINLOG_HEAD));
        return $head == self::BINLOG_HEAD;
    }
 
    /**
     * @param resource $file
     *
     * Format description event is the first event of a binlog file
     */
    protected function readFormatDescriptionEvent($file) {
        fseek($file, strlen(self::BINLOG_HEAD), SEEK_SET);
        $head_str = fread($file, self::EVENT_HEAD_SIZE);