wsgi.py 文件源码

def __call__(self, request):
        data = {}
        response = []

        def start_response(status, response_headers, exc_info=None):
            data["status"] = status
            data["headers"] = response_headers
            return response.append
        app_response = self.wsgi_application(
            WSGIContainer.environ(request), start_response)
        try:
            response.extend(app_response)
            body = b"".join(response)
        finally:
            if hasattr(app_response, "close"):
                app_response.close()
        if not data:
            raise Exception("WSGI app did not call start_response")

        status_code, reason = data["status"].split(' ', 1)
        status_code = int(status_code)
        headers = data["headers"]
        header_set = set(k.lower() for (k, v) in headers)
        body = escape.utf8(body)
        if status_code != 304:
            if "content-length" not in header_set:
                headers.append(("Content-Length", str(len(body))))
            if "content-type" not in header_set:
                headers.append(("Content-Type", "text/html; charset=UTF-8"))
        if "server" not in header_set:
            headers.append(("Server", "TornadoServer/%s" % tornado.version))

        start_line = httputil.ResponseStartLine("HTTP/1.1", status_code, reason)
        header_obj = httputil.HTTPHeaders()
        for key, value in headers:
            header_obj.add(key, value)
        request.connection.write_headers(start_line, header_obj, chunk=body)
        request.connection.finish()
        self._log(status_code, request)