Source code for tornado.wsgi

#!/usr/bin/env python
# Copyright 2009 Facebook
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

"""WSGI support for the Tornado web framework.

WSGI is the Python standard for web servers, and allows for interoperability
between Tornado and other Python web frameworks and servers.  This module
provides WSGI support in two ways:

* `WSGIApplication` is a version of `tornado.web.Application` that can run
  inside a WSGI server.  This is useful for running a Tornado app on another
  HTTP server, such as Google App Engine.  See the `WSGIApplication` class
  documentation for limitations that apply.
* `WSGIContainer` lets you run other WSGI applications and frameworks on the
  Tornado HTTP server.  For example, with this class you can mix Django
  and Tornado handlers in a single server.

from __future__ import absolute_import, division, with_statement

import Cookie
import httplib
import logging
import sys
import time
import tornado
import urllib

from tornado import escape
from tornado import httputil
from tornado import web
from tornado.escape import native_str, utf8, parse_qs_bytes
from tornado.util import b, bytes_type

    from io import BytesIO  # python 3
except ImportError:
    from cStringIO import StringIO as BytesIO  # python 2

# PEP 3333 specifies that WSGI on python 3 generally deals with byte strings
# that are smuggled inside objects of type unicode (via the latin1 encoding).
# These functions are like those in the tornado.escape module, but defined
# here to minimize the temptation to use them in non-wsgi contexts.
if str is unicode:
    def to_wsgi_str(s):
        assert isinstance(s, bytes_type)
        return s.decode('latin1')

    def from_wsgi_str(s):
        assert isinstance(s, str)
        return s.encode('latin1')
    def to_wsgi_str(s):
        assert isinstance(s, bytes_type)
        return s

    def from_wsgi_str(s):
        assert isinstance(s, str)
        return s

[docs]class WSGIApplication(web.Application): """A WSGI equivalent of `tornado.web.Application`. WSGIApplication is very similar to web.Application, except no asynchronous methods are supported (since WSGI does not support non-blocking requests properly). If you call self.flush() or other asynchronous methods in your request handlers running in a WSGIApplication, we throw an exception. Example usage:: import tornado.web import tornado.wsgi import wsgiref.simple_server class MainHandler(tornado.web.RequestHandler): def get(self): self.write("Hello, world") if __name__ == "__main__": application = tornado.wsgi.WSGIApplication([ (r"/", MainHandler), ]) server = wsgiref.simple_server.make_server('', 8888, application) server.serve_forever() See the 'appengine' demo for an example of using this module to run a Tornado app on Google AppEngine. Since no asynchronous methods are available for WSGI applications, the httpclient and auth modules are both not available for WSGI applications. We support the same interface, but handlers running in a WSGIApplication do not support flush() or asynchronous methods. """ def __init__(self, handlers=None, default_host="", **settings): web.Application.__init__(self, handlers, default_host, transforms=[], wsgi=True, **settings) def __call__(self, environ, start_response): handler = web.Application.__call__(self, HTTPRequest(environ)) assert handler._finished status = str(handler._status_code) + " " + \ httplib.responses[handler._status_code] headers = handler._headers.items() + handler._list_headers if hasattr(handler, "_new_cookie"): for cookie in handler._new_cookie.values(): headers.append(("Set-Cookie", cookie.OutputString(None))) start_response(status, [(native_str(k), native_str(v)) for (k, v) in headers]) return handler._write_buffer
[docs]class HTTPRequest(object): """Mimics `tornado.httpserver.HTTPRequest` for WSGI applications.""" def __init__(self, environ): """Parses the given WSGI environ to construct the request.""" self.method = environ["REQUEST_METHOD"] self.path = urllib.quote(from_wsgi_str(environ.get("SCRIPT_NAME", ""))) self.path += urllib.quote(from_wsgi_str(environ.get("PATH_INFO", ""))) self.uri = self.path self.arguments = {} self.query = environ.get("QUERY_STRING", "") if self.query: self.uri += "?" + self.query arguments = parse_qs_bytes(native_str(self.query)) for name, values in arguments.iteritems(): values = [v for v in values if v] if values: self.arguments[name] = values self.version = "HTTP/1.1" self.headers = httputil.HTTPHeaders() if environ.get("CONTENT_TYPE"): self.headers["Content-Type"] = environ["CONTENT_TYPE"] if environ.get("CONTENT_LENGTH"): self.headers["Content-Length"] = environ["CONTENT_LENGTH"] for key in environ: if key.startswith("HTTP_"): self.headers[key[5:].replace("_", "-")] = environ[key] if self.headers.get("Content-Length"): self.body = environ["wsgi.input"].read( int(self.headers["Content-Length"])) else: self.body = "" self.protocol = environ["wsgi.url_scheme"] self.remote_ip = environ.get("REMOTE_ADDR", "") if environ.get("HTTP_HOST"): = environ["HTTP_HOST"] else: = environ["SERVER_NAME"] # Parse request body self.files = {} httputil.parse_body_arguments(self.headers.get("Content-Type", ""), self.body, self.arguments, self.files) self._start_time = time.time() self._finish_time = None
[docs] def supports_http_1_1(self): """Returns True if this request supports HTTP/1.1 semantics""" return self.version == "HTTP/1.1"
[docs] def cookies(self): """A dictionary of Cookie.Morsel objects.""" if not hasattr(self, "_cookies"): self._cookies = Cookie.SimpleCookie() if "Cookie" in self.headers: try: self._cookies.load( native_str(self.headers["Cookie"])) except Exception: self._cookies = None return self._cookies
[docs] def full_url(self): """Reconstructs the full URL for this request.""" return self.protocol + "://" + + self.uri
[docs] def request_time(self): """Returns the amount of time it took for this request to execute.""" if self._finish_time is None: return time.time() - self._start_time else: return self._finish_time - self._start_time
[docs]class WSGIContainer(object): r"""Makes a WSGI-compatible function runnable on Tornado's HTTP server. Wrap a WSGI function in a WSGIContainer and pass it to HTTPServer to run it. For example:: def simple_app(environ, start_response): status = "200 OK" response_headers = [("Content-type", "text/plain")] start_response(status, response_headers) return ["Hello world!\n"] container = tornado.wsgi.WSGIContainer(simple_app) http_server = tornado.httpserver.HTTPServer(container) http_server.listen(8888) tornado.ioloop.IOLoop.instance().start() This class is intended to let other frameworks (Django,, etc) run on the Tornado HTTP server and I/O loop. The `tornado.web.FallbackHandler` class is often useful for mixing Tornado and WSGI apps in the same server. See for a complete example. """ def __init__(self, wsgi_application): self.wsgi_application = wsgi_application 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) response.extend(app_response) body = b("").join(response) if hasattr(app_response, "close"): app_response.close() if not data: raise Exception("WSGI app did not call start_response") status_code = int(data["status"].split()[0]) headers = data["headers"] header_set = set(k.lower() for (k, v) in headers) body = escape.utf8(body) 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)) parts = [escape.utf8("HTTP/1.1 " + data["status"] + "\r\n")] for key, value in headers: parts.append(escape.utf8(key) + b(": ") + escape.utf8(value) + b("\r\n")) parts.append(b("\r\n")) parts.append(body) request.write(b("").join(parts)) request.finish() self._log(status_code, request) @staticmethod
[docs] def environ(request): """Converts a `tornado.httpserver.HTTPRequest` to a WSGI environment. """ hostport =":") if len(hostport) == 2: host = hostport[0] port = int(hostport[1]) else: host = port = 443 if request.protocol == "https" else 80 environ = { "REQUEST_METHOD": request.method, "SCRIPT_NAME": "", "PATH_INFO": to_wsgi_str(escape.url_unescape(request.path, encoding=None)), "QUERY_STRING": request.query, "REMOTE_ADDR": request.remote_ip, "SERVER_NAME": host, "SERVER_PORT": str(port), "SERVER_PROTOCOL": request.version, "wsgi.version": (1, 0), "wsgi.url_scheme": request.protocol, "wsgi.input": BytesIO(escape.utf8(request.body)), "wsgi.errors": sys.stderr, "wsgi.multithread": False, "wsgi.multiprocess": True, "wsgi.run_once": False, } if "Content-Type" in request.headers: environ["CONTENT_TYPE"] = request.headers.pop("Content-Type") if "Content-Length" in request.headers: environ["CONTENT_LENGTH"] = request.headers.pop("Content-Length") for key, value in request.headers.iteritems(): environ["HTTP_" + key.replace("-", "_").upper()] = value return environ
def _log(self, status_code, request): if status_code < 400: log_method = elif status_code < 500: log_method = logging.warning else: log_method = logging.error request_time = 1000.0 * request.request_time() summary = request.method + " " + request.uri + " (" + \ request.remote_ip + ")" log_method("%d %s %.2fms", status_code, summary, request_time)