def stream(
        self,
        stream,
        chunk_size=DEFAULT_CHUNK_SIZE,
        request=None,
        attachment=False,
        filename=None
        ):
        """
        If in a controller function::

            return response.stream(file, 100)

        the file content will be streamed at 100 bytes at the time

        Args:
            stream: filename or read()able content
            chunk_size(int): Buffer size
            request: the request object
            attachment(bool): prepares the correct headers to download the file
                as an attachment. Usually creates a pop-up download window
                on browsers
            filename(str): the name for the attachment

        Note:
            for using the stream name (filename) with attachments
            the option must be explicitly set as function parameter (will
            default to the last request argument otherwise)
        """

        headers = self.headers
        # for attachment settings and backward compatibility
        keys = [item.lower() for item in headers]
        if attachment:
            if filename is None:
                attname = ""
            else:
                attname = filename
            headers["Content-Disposition"] = \
                "attachment;filename=%s" % attname

        if not request:
            request = current.request
        if isinstance(stream, (str, unicode)):
            stream_file_or_304_or_206(stream,
                                      chunk_size=chunk_size,
                                      request=request,
                                      headers=headers,
                                      status=self.status)

        # ## the following is for backward compatibility
        if hasattr(stream, 'name'):
            filename = stream.name

        if filename and not 'content-type' in keys:
            headers['Content-Type'] = contenttype(filename)
        if filename and not 'content-length' in keys:
            try:
                headers['Content-Length'] = \
                    os.path.getsize(filename)
            except OSError:
                pass

        env = request.env
        # Internet Explorer < 9.0 will not allow downloads over SSL unless caching is enabled
        if request.is_https and isinstance(env.http_user_agent, str) and \
                not re.search(r'Opera', env.http_user_agent) and \
                re.search(r'MSIE [5-8][^0-9]', env.http_user_agent):
            headers['Pragma'] = 'cache'
            headers['Cache-Control'] = 'private'

        if request and env.web2py_use_wsgi_file_wrapper:
            wrapped = env.wsgi_file_wrapper(stream, chunk_size)
        else:
            wrapped = streamer(stream, chunk_size=chunk_size)
        return wrapped
dataset/ETHPy150Open uwdata/termite-data-server/web2py/gluon/globals.py/Response.stream/original