RangeHeader\RangeHeader::__construct PHP Метод

    public function __construct($http_range_header, $file_path)
    {
        // Simulate basic support for the Content-Range header.
        preg_match('/bytes=(\\d+)?-(\\d+)?/', $http_range_header, $matches);
        $this->first_byte = isset($matches['1']) ? (int) $matches['1'] : null;
        $this->last_byte = isset($matches['2']) ? (int) $matches['2'] : null;
        $this->filesize = filesize($file_path);
        // Start position begins after end of file.
        if ($this->first_byte >= $this->filesize) {
            $this->is_valid = false;
        }
        // "If the last-byte-pos value is present, it MUST be greater than or equal to the first-byte-pos in that
        // byte-range-spec, or the byte- range-spec is syntactically invalid."
        if (!($this->last_byte === null) && !($this->last_byte >= $this->first_byte)) {
            $this->is_valid = false;
        }
    }