import asyncio
import fnmatch
import json
import logging
import os
import threading
import time
import webbrowser
from functools import partial
from typing import Dict
from urllib.parse import urlparse
import tornado
import tornado.httpserver
import tornado.ioloop
from tornado.web import StaticFileHandler
from tornado.websocket import WebSocketHandler
from . import utils
from .remote_access import start_remote_access_service
from .utils import make_applications, render_page, cdn_validation, deserialize_binary_event
from ..session import CoroutineBasedSession, ThreadBasedSession, ScriptModeSession, \
register_session_implement_for_target, Session
from ..session.base import get_session_info_from_headers
from ..utils import get_free_port, wait_host_port, STATIC_PATH, iscoroutinefunction, isgeneratorfunction, \
check_webio_js, parse_file_size, random_str, LRUDict
logger = logging.getLogger(__name__)
_ioloop = None
def set_ioloop(loop):
global _ioloop
_ioloop = loop
def ioloop() -> tornado.ioloop.IOLoop:
"""获得运行Tornado server的IOLoop
本方法当前仅在显示boken app时使用
This method is currently only used when displaying boken app"""
global _ioloop
return _ioloop
def _check_origin(origin, allowed_origins, handler: WebSocketHandler):
if _is_same_site(origin, handler):
return True
return any(
fnmatch.fnmatch(origin, patten)
for patten in allowed_origins
)
def _is_same_site(origin, handler: WebSocketHandler):
parsed_origin = urlparse(origin)
origin = parsed_origin.netloc
origin = origin.lower()
host = handler.request.headers.get("Host")
# Check to see that origin matches host directly, including ports
return origin == host
def _webio_handler(applications=None, cdn=True, reconnect_timeout=0, check_origin_func=_is_same_site):
"""
:param dict applications: dict of `name -> task function`
:param bool/str cdn: Whether to load front-end static resources from CDN
:param callable check_origin_func: check_origin_func(origin, handler) -> bool
:return: Tornado RequestHandler class
"""
check_webio_js()
if applications is None:
applications = dict(index=lambda: None) # mock PyWebIO app
class WSHandler(WebSocketHandler):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._close_from_session = False
self.session_id = None
self.session = None # type: Session
if reconnect_timeout and not type(self)._started_clean_task:
type(self)._started_clean_task = True
tornado.ioloop.IOLoop.current().call_later(reconnect_timeout // 2, type(self).clean_expired_sessions)
logger.debug("Started session clean task")
def get_app(self):
app_name = self.get_query_argument('app', 'index')
app = applications.get(app_name) or applications['index']
return app
async def get(self, *args, **kwargs) -> None:
# It's a simple http GET request
if self.request.headers.get("Upgrade", "").lower() != "websocket":
# Backward compatible
# Frontend detect whether the backend is http server
if self.get_query_argument('test', ''):
return self.write('')
app = self.get_app()
html = render_page(app, protocol='ws', cdn=cdn)
return self.write(html)
else:
await super().get()
def check_origin(self, origin):
return check_origin_func(origin=origin, handler=self)
def get_compression_options(self):
# Non-None enables compression with default options.
return {}
@classmethod
def clean_expired_sessions(cls):
tornado.ioloop.IOLoop.current().call_later(reconnect_timeout // 2, cls.clean_expired_sessions)
while cls._session_expire:
session_id, expire_ts = cls._session_expire.popitem(last=False) # 弹出最早过期的session
if time.time() < expire_ts:
# this session is not expired
cls._session_expire[session_id] = expire_ts # restore this item
cls._session_expire.move_to_end(session_id, last=False) # move to front
break
# clean this session
logger.debug("session %s expired" % session_id)
cls._connections.pop(session_id, None)
session = cls._webio_sessions.pop(session_id, None)
if session:
session.close(nonblock=True)
@classmethod
def send_msg_to_client(cls, _, session_id=None):
conn = cls._connections.get(session_id)
session = cls._webio_sessions[session_id]
if not conn or not conn.ws_connection:
return
for msg in session.get_task_commands():
conn.write_message(json.dumps(msg))
@classmethod
def close_from_session(cls, session_id=None):
cls.send_msg_to_client(None, session_id=session_id)
conn = cls._connections.pop(session_id, None)
cls._webio_sessions.pop(session_id, None)
if conn and conn.ws_connection:
conn._close_from_session = True
conn.close()
_started_clean_task = False
_session_expire = LRUDict() # session_id -> expire timestamp. In increasing order of expire time
_webio_sessions = {} # type: Dict[str, Session] # session_id -> session
_connections = {} # type: Dict[str, WSHandler] # session_id -> WSHandler
def open(self):
logger.debug("WebSocket opened")
cls = type(self)
self.session_id = self.get_query_argument('session', None)
if self.session_id in ('NEW', None): # 初始请求，创建新 Session
session_info = get_session_info_from_headers(self.request.headers)
session_info['user_ip'] = self.request.remote_ip
session_info['request'] = self.request
session_info['backend'] = 'tornado'
session_info['protocol'] = 'websocket'
application = self.get_app()
self.session_id = random_str(24)
cls._connections[self.session_id] = self
if iscoroutinefunction(application) or isgeneratorfunction(application):
self.session = CoroutineBasedSession(
application, session_info=session_info,
on_task_command=partial(self.send_msg_to_client, session_id=self.session_id),
on_session_close=partial(self.close_from_session, session_id=self.session_id))
else:
self.session = ThreadBasedSession(
application, session_info=session_info,
on_task_command=partial(self.send_msg_to_client, session_id=self.session_id),
on_session_close=partial(self.close_from_session, session_id=self.session_id),
loop=asyncio.get_event_loop())
cls._webio_sessions[self.session_id] = self.session
if reconnect_timeout:
self.write_message(json.dumps(dict(command='set_session_id', spec=self.session_id)))
elif self.session_id not in cls._webio_sessions: # WebIOSession deleted
self.write_message(json.dumps(dict(command='close_session')))
else:
self.session = cls._webio_sessions[self.session_id]
cls._session_expire.pop(self.session_id, None)
cls._connections[self.session_id] = self
cls.send_msg_to_client(self.session, self.session_id)
logger.debug('session id: %s' % self.session_id)
def on_message(self, message):
if isinstance(message, bytes):
event = deserialize_binary_event(message)
else:
event = json.loads(message)
if event is None:
return
self.session.send_client_event(event)
def on_close(self):
cls = type(self)
cls._connections.pop(self.session_id, None)
if not reconnect_timeout and not self._close_from_session:
self.session.close(nonblock=True)
elif reconnect_timeout:
if self._close_from_session:
cls._webio_sessions.pop(self.session_id, None)
elif self.session:
cls._session_expire[self.session_id] = time.time() + reconnect_timeout
logger.debug("WebSocket closed")
return WSHandler
[docs]def webio_handler(applications, cdn=True, reconnect_timeout=0, allowed_origins=None, check_origin=None):
"""Get the ``RequestHandler`` class for running PyWebIO applications in Tornado.
The ``RequestHandler`` communicates with the browser by WebSocket protocol.
The arguments of ``webio_handler()`` have the same meaning as for :func:`pywebio.platform.tornado.start_server`
"""
applications = make_applications(applications)
for target in applications.values():
register_session_implement_for_target(target)
cdn = cdn_validation(cdn, 'error') # if CDN is not available, raise error
if check_origin is None:
check_origin_func = partial(_check_origin, allowed_origins=allowed_origins or [])
else:
check_origin_func = lambda origin, handler: _is_same_site(origin, handler) or check_origin(origin)
return _webio_handler(applications=applications, cdn=cdn, check_origin_func=check_origin_func,
reconnect_timeout=reconnect_timeout)
async def open_webbrowser_on_server_started(host, port):
url = 'http://%s:%s' % (host, port)
is_open = await wait_host_port(host, port, duration=20)
if is_open:
logger.info('Try open %s in web browser' % url)
# webbrowser.open() may block, so invoke it in thread
threading.Thread(target=webbrowser.open, args=(url,), daemon=True).start()
else:
logger.error('Open %s in web browser failed.' % url)
def _setup_server(webio_handler, port=0, host='', static_dir=None, max_buffer_size=2 ** 20 * 200,
**tornado_app_settings):
if port == 0:
port = get_free_port()
handlers = [(r"/", webio_handler)]
if static_dir is not None:
handlers.append((r"/static/(.*)", StaticFileHandler, {"path": static_dir}))
handlers.append((r"/(.*)", StaticFileHandler, {"path": STATIC_PATH, 'default_filename': 'index.html'}))
app = tornado.web.Application(handlers=handlers, **tornado_app_settings)
# Credit: https://stackoverflow.com/questions/19074972/content-length-too-long-when-uploading-file-using-tornado
server = app.listen(port, address=host, max_buffer_size=max_buffer_size)
return server, port
[docs]def start_server(applications, port=0, host='',
debug=False, cdn=True, static_dir=None,
remote_access=False,
reconnect_timeout=0,
allowed_origins=None, check_origin=None,
auto_open_webbrowser=False,
max_payload_size='200M',
**tornado_app_settings):
"""Start a Tornado server to provide the PyWebIO application as a web service.
The Tornado server communicates with the browser by WebSocket protocol.
Tornado is the default backend server for PyWebIO applications,
and ``start_server`` can be imported directly using ``from pywebio import start_server``.
:param list/dict/callable applications: PyWebIO application.
Can be a task function, a list of functions, or a dictionary.
When it is a dictionary, whose key is task name and value is task function.
When it is a list, using function name as task name.
You can select the task to run through the ``app`` URL parameter (for example, visit ``http://host:port/?app=foo`` to run the ``foo`` task),
By default, the ``index`` task function is used. When the ``index`` task does not exist, PyWebIO will provide a default index home page.
See also :ref:`Server mode <server_and_script_mode>`
When the task function is a coroutine function, use :ref:`Coroutine-based session <coroutine_based_session>` implementation,
otherwise, use thread-based session implementation.
:param int port: The port the server listens on.
When set to ``0``, the server will automatically select a available port.
:param str host: The host the server listens on. ``host`` may be either an IP address or hostname. If it’s a hostname, the server will listen on all IP addresses associated with the name. ``host`` may be an empty string or None to listen on all available interfaces.
:param bool debug: Tornado Server's debug mode. If enabled, the server will automatically reload for code changes.
See `tornado doc <https://www.tornadoweb.org/en/stable/guide/running.html#debug-mode>`_ for more detail.
:param bool/str cdn: Whether to load front-end static resources from CDN, the default is ``True``.
Can also use a string to directly set the url of PyWebIO static resources.
:param str static_dir: The directory to store the application static files.
The files in this directory can be accessed via ``http://<host>:<port>/static/files``.
For example, if there is a ``A/B.jpg`` file in ``http_static_dir`` path,
it can be accessed via ``http://<host>:<port>/static/A/B.jpg``.
:param bool/dict remote_access: Whether to enable remote access, when enabled,
you can get a temporary public network access address for the current application,
others can access your application via this address.
Using remote access makes it easy to temporarily share the application with others.
The remote access service is provided by `localhost.run <https://localhost.run/>`_.
You can use a dict to config remote access service, the following configurations are currently supported:
- ``ssh_key_path``: Use a custom ssh key, the default key path is ``~/.ssh/id_xxx``. Note that only rsa and ed25519 keys are supported.
- ``custom_domain``: Use a custom domain for your remote access address. This need a subscription to localhost.run.
See also: `Custom Domains - localhost.run <https://localhost.run/docs/custom-domains/>`_
:param bool auto_open_webbrowser: Whether or not auto open web browser when server is started (if the operating system allows it) .
:param int reconnect_timeout: The client can reconnect to server within ``reconnect_timeout`` seconds after an unexpected disconnection.
If set to 0 (default), once the client disconnects, the server session will be closed.
:param list allowed_origins: The allowed request source list. (The current server host is always allowed)
The source contains the protocol, domain name, and port part.
Can use Unix shell-style wildcards:
- ``*`` matches everything
- ``?`` matches any single character
- ``[seq]`` matches any character in *seq*
- ``[!seq]`` matches any character not in *seq*
Such as: ``https://*.example.com`` 、 ``*://*.example.com``
For detail, see `Python Doc <https://docs.python.org/zh-tw/3/library/fnmatch.html>`_
:param callable check_origin: The validation function for request source.
It receives the source string (which contains protocol, host, and port parts) as parameter and return ``True/False`` to indicate that the server accepts/rejects the request.
If ``check_origin`` is set, the ``allowed_origins`` parameter will be ignored.
:param bool auto_open_webbrowser: Whether or not auto open web browser when server is started (if the operating system allows it) .
:param int/str max_payload_size: Max size of a websocket message which Tornado can accept.
Messages larger than the ``max_payload_size`` (default 200MB) will not be accepted.
``max_payload_size`` can be a integer indicating the number of bytes, or a string ending with `K` / `M` / `G`
(representing kilobytes, megabytes, and gigabytes, respectively).
E.g: ``500``, ``'40K'``, ``'3M'``
:param tornado_app_settings: Additional keyword arguments passed to the constructor of ``tornado.web.Application``.
For details, please refer: https://www.tornadoweb.org/en/stable/web.html#tornado.web.Application.settings
"""
set_ioloop(tornado.ioloop.IOLoop.current()) # to enable bokeh app
cdn = cdn_validation(cdn, 'warn') # if CDN is not available, warn user and disable CDN
utils.MAX_PAYLOAD_SIZE = max_payload_size = parse_file_size(max_payload_size)
tornado_app_settings.setdefault('websocket_max_message_size', max_payload_size) # Backward compatible
tornado_app_settings['websocket_max_message_size'] = parse_file_size(
tornado_app_settings['websocket_max_message_size'])
tornado_app_settings['debug'] = debug
handler = webio_handler(applications, cdn, allowed_origins=allowed_origins, check_origin=check_origin,
reconnect_timeout=reconnect_timeout)
_, port = _setup_server(webio_handler=handler, port=port, host=host, static_dir=static_dir,
max_buffer_size=max_payload_size, **tornado_app_settings)
print('Listen on %s:%s' % (host or '0.0.0.0', port))
if auto_open_webbrowser:
tornado.ioloop.IOLoop.current().spawn_callback(open_webbrowser_on_server_started, host or 'localhost', port)
if remote_access or remote_access == {}:
if remote_access is True: remote_access = {}
start_remote_access_service(**remote_access, local_port=port)
tornado.ioloop.IOLoop.current().start()
def start_server_in_current_thread_session():
"""启动 script mode 的server，监听可用端口，并自动打开浏览器
Start the server for script mode, and automatically open the browser when the server port is available.
PYWEBIO_SCRIPT_MODE_PORT环境变量可以设置监听端口，并关闭自动打开浏览器，用于测试
The PYWEBIO_SCRIPT_MODE_PORT environment variable can set the listening port, just used in testing.
"""
websocket_conn_opened = threading.Event()
thread = threading.current_thread()
class SingleSessionWSHandler(_webio_handler(cdn=False)):
session = None
instance = None
def open(self):
self.main_session = False
cls = type(self)
if SingleSessionWSHandler.session is None:
self.main_session = True
SingleSessionWSHandler.instance = self
self.session_id = 'main'
cls._connections[self.session_id] = self
session_info = get_session_info_from_headers(self.request.headers)
session_info['user_ip'] = self.request.remote_ip
session_info['request'] = self.request
session_info['backend'] = 'tornado'
session_info['protocol'] = 'websocket'
self.session = SingleSessionWSHandler.session = ScriptModeSession(
thread, session_info=session_info,
on_task_command=partial(self.send_msg_to_client, session_id=self.session_id),
loop=asyncio.get_event_loop())
websocket_conn_opened.set()
cls._webio_sessions[self.session_id] = self.session
else:
self.close()
def on_close(self):
if SingleSessionWSHandler.session is not None and self.main_session:
self.session.close()
logger.debug('ScriptModeSession closed')
async def wait_to_stop_loop(server):
"""当只剩当前线程和Daemon线程运行时，关闭Server
When only the current thread and Daemon thread are running, close the Server"""
# 包括当前线程在内的非Daemon线程数
# The number of non-Daemon threads(including the current thread)
alive_none_daemonic_thread_cnt = None
while alive_none_daemonic_thread_cnt != 1:
alive_none_daemonic_thread_cnt = sum(
1 for t in threading.enumerate() if t.is_alive() and not t.isDaemon()
)
await asyncio.sleep(1)
# 关闭Websocket连接
# Close the Websocket connection
if SingleSessionWSHandler.instance:
SingleSessionWSHandler.instance.close()
server.stop()
logger.debug('Closing tornado ioloop...')
tasks = [t for t in asyncio.all_tasks() if t is not asyncio.current_task() and not t.done()]
for task in tasks: task.cancel()
# 必须需要 await asyncio.sleep ，否则上方 task.cancel() 调用无法调度生效
# This line must be required, otherwise the `task.cancel()` call cannot be scheduled to take effect
await asyncio.sleep(0)
tornado.ioloop.IOLoop.current().stop()
def server_thread():
from tornado.log import access_log, app_log, gen_log
access_log.setLevel(logging.ERROR)
app_log.setLevel(logging.ERROR)
gen_log.setLevel(logging.ERROR)
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
set_ioloop(tornado.ioloop.IOLoop.current()) # to enable bokeh app
port = 0
if os.environ.get("PYWEBIO_SCRIPT_MODE_PORT"):
port = int(os.environ.get("PYWEBIO_SCRIPT_MODE_PORT"))
server, port = _setup_server(webio_handler=SingleSessionWSHandler, port=port, host='localhost',
websocket_max_message_size=parse_file_size('4G'))
tornado.ioloop.IOLoop.current().spawn_callback(partial(wait_to_stop_loop, server=server))
if "PYWEBIO_SCRIPT_MODE_PORT" not in os.environ:
tornado.ioloop.IOLoop.current().spawn_callback(open_webbrowser_on_server_started, 'localhost', port)
tornado.ioloop.IOLoop.current().start()
logger.debug('Tornado server exit')
t = threading.Thread(target=server_thread, name='Tornado-server')
t.start()
websocket_conn_opened.wait()