django-ddp/dddp/server.py
2015-02-23 15:29:18 +11:00

414 lines
12 KiB
Python

"""Django DDP WebSocket service."""
from __future__ import print_function
import collections
import gevent.monkey
import psycogreen.gevent
gevent.monkey.patch_all()
psycogreen.gevent.patch_psycopg()
import inspect
import random
import signal
import socket # green
import sys
import traceback
import uuid
import ejson
import gevent
import gevent.queue
import gevent.select
import geventwebsocket
import psycopg2 # green
import psycopg2.extras
from django.db import connection
sub_queue = gevent.queue.Queue()
unsub_queue = gevent.queue.Queue()
all_subs = collections.defaultdict(list)
def subscribe(func, name, params):
sub_queue.put((func, name, params))
def unsubscribe(func, name, params):
unsub_queue.put((func, name, params))
def pg_loop(conn):
if gevent.select.select([conn], [], [], 5) == ([], [], []):
print("Timeout")
else:
pg_wait(conn)
def pg_wait(conn):
while True:
state = conn.poll()
if state == psycopg2.extensions.POLL_OK:
while conn.notifies:
notify = conn.notifies.pop()
name = notify.channel
print("Got NOTIFY:", notify.pid, name, notify.payload)
subs = all_subs[name]
data = ejson.loads(notify.payload)
for (func, params) in subs:
try:
gevent.spawn(func, name, params, data)
#func(name, params, data)
except Exception, err:
print("Callback error: %s" % err)
traceback.print_exc()
break
elif state == psycopg2.extensions.POLL_WRITE:
print('POLL_WRITE')
gevent.select.select([], [conn.fileno()], [])
elif state == psycopg2.extensions.POLL_READ:
print('POLL_READ')
gevent.select.select([conn.fileno()], [], [])
else:
print('POLL_ERR: %s' % state)
raise psycopg2.OperationalError("poll() returned %s" % state)
def pg_listen():
conn_params = connection.get_connection_params()
conn_params['async'] = True
#psycopg2.extensions.set_wait_callback(psycopg2.extras.wait_select)
#pg_wait = psycopg2.extras.wait_select
conn = connection.get_new_connection(conn_params)
#pg_wait(conn)
pg_wait(conn)
#psycopg2.extras.wait_select(conn)
cur = conn.cursor()
#cur.execute('LISTEN "survey.response";')
print('LISTEN')
while 1:
try:
func, name, params = sub_queue.get_nowait()
subs = all_subs[name]
if len(subs) == 0:
print('LISTEN "%s";' % name)
cur.execute('LISTEN "%s";' % name)
subs.append((func, params))
except gevent.queue.Empty:
pass
try:
func, name, params = unsub_queue.get_nowait()
subs = all_subs[name]
subs.remove(func, params)
if len(subs) == 0:
print('UNLISTEN "%s";' % name)
cur.execute('UNLISTEN "%s";' % name)
except gevent.queue.Empty:
pass
pg_loop(conn)
#psycopg2.extras.wait_select(conn)
class MeteorError(Exception):
"""MeteorError."""
pass
def validate_kwargs(func, kwargs, func_name=None):
"""Validate arguments to be supplied to func."""
if func_name is None:
func_name = func.__name__
argspec = inspect.getargspec(func)
args = argspec.args[:]
# ignore implicit 'self' argument
if inspect.ismethod(func):
args[:1] = []
# translate 'foo' args into 'foo_' to avoid crap argument names
for key in list(kwargs):
key_adj = '%s_' % key
if key_adj in args:
kwargs[key_adj] = kwargs.pop(key)
required = args[:-len(argspec.defaults)]
supplied = sorted(kwargs)
missing = [
arg for arg in required
if arg not in supplied
]
if missing:
raise MeteorError(
'Missing required arguments to %s: %s' % (
func_name,
' '.join(missing),
),
)
extra = [
arg for arg in supplied
if arg not in args
]
if extra:
raise MeteorError(
'Unknown arguments to %s: %s' % (
func_name,
' '.join(extra),
),
)
class DDPApplication(geventwebsocket.WebSocketApplication):
"""Django DDP WebSocket application."""
methods = {}
versions = [ # first item is preferred version
'1',
'pre1',
'pre2',
]
remote_addr = None
version = None
support = None
session = None
subs = None
#def __init__(self, environ, start_response, *args, **kwargs):
# print('INIT: %r %r' % (args, kwargs))
# super_init = super(DDPApplication, self).__init__
# print(inspect.getargspec(super_init))
# return super_init(environ, start_response, *args, **kwargs)
def on_open(self):
"""Handle new websocket connection."""
self.remote_addr = '{0[REMOTE_ADDR]}:{0[REMOTE_PORT]}'.format(
self.ws.environ,
)
self.subs = {}
print('+ %s OPEN' % self)
self.send('o')
self.send('a["{\\"server_id\\":\\"0\\"}"]')
def __str__(self):
"""Show remote address that connected to us."""
return self.remote_addr
def on_close(self, reason):
"""Handle closing of websocket connection."""
print('- %s %s' % (self, reason or 'CLOSE'))
def on_message(self, raw):
"""Process a message received from remote."""
if self.ws.closed:
return None
try:
print('< %s %r' % (self, raw))
data = ejson.loads(raw)
data = ejson.loads(data[0])
try:
msg = data.pop('msg')
except (AttributeError, TypeError, IndexError):
raise MeteorError('Invalid EJSON message type.')
except KeyError:
raise MeteorError('Missing required field: msg')
else:
self.dispatch(msg, data)
except geventwebsocket.WebSocketError, err:
self.on_close(err)
except Exception, err:
self.error(err)
def dispatch(self, msg, kwargs):
"""Dispatch msg to appropriate recv_foo handler."""
# enforce calling 'connect' first
if not self.session and msg != 'connect':
raise MeteorError("Session not establised - try 'connect'.")
# lookup method handler
try:
handler = getattr(self, 'recv_%s' % msg)
except (AttributeError, UnicodeEncodeError):
raise MeteorError(404, 'Method not found')
# validate handler arguments
validate_kwargs(handler, kwargs)
# dispatch to handler
try:
handler(**kwargs)
except Exception, err:
raise MeteorError(500, 'Internal server error', err)
def send(self, data):
print('> %s %r' % (self, data))
self.ws.send(data)
def reply(self, msg, **kwargs):
"""Send EJSON reply to remote."""
kwargs['msg'] = msg
data = ejson.dumps([ejson.dumps(kwargs)])
self.send('a%s' % data)
def error(self, err, reason=None, detail=None):
"""Send EJSON error to remote."""
if isinstance(err, MeteorError):
(err, reason, detail) = (err.args[:] + (None, None, None))[:3]
if not err:
err = '<UNKNOWN_ERROR>'
data = {
'error': err,
}
if reason:
data['reason'] = reason
if detail:
data['detail'] = detail
print('! %s %r' % (self, data))
self.reply('error', **data)
def recv_connect(self, version, support, session=None):
"""DDP connect handler."""
if self.session:
self.error(
'Session already established.',
reason='Current session in detail.',
detail=self.session,
)
elif version not in self.versions:
self.reply('failed', version=self.versions[0])
elif version not in support:
self.error('Client version/support mismatch.')
else:
if not session:
session = uuid.uuid4().hex
self.version = version
self.support = support
self.session = session
self.reply('connected', session=self.session)
def recv_ping(self, id_=None):
"""DDP ping handler."""
if id_ is None:
self.reply('pong')
else:
self.reply('pong', id=id_)
def sub_notify(self, name, params, data):
self.reply(**data)
def recv_sub(self, id_, name, params=None):
"""DDP sub handler."""
print('recv_sub: %r %r %r' % (id_, name, params))
subscribe(self.sub_notify, name, params)
self.reply('ready', subs=[id_])
def recv_unsub(self, id_):
"""DDP unsub handler."""
unsubscribe(self.sub_notify, name, params)
def recv_method(self, method, params, id_, randomSeed=None):
"""DDP method handler."""
try:
func = self.methods[method]
except KeyError:
self.reply('result', id=id_, error=u'Unknown method: %s' % method)
else:
try:
self.reply('result', id=id_, result=func(**params))
except Exception, err:
self.reply('result', id=id_, error='%s' % err)
finally:
pass
def ddpp_sockjs_xhr(environ, start_response):
start_response(
'404 Not found',
[
('Content-Type', 'text/plain; charset=UTF-8'),
(
'Access-Control-Allow-Origin',
'%s://%s:3000' % (
environ['wsgi.url_scheme'],
environ['HTTP_HOST'].split(':')[0],
),
),
('Access-Control-Allow-Credentials', 'true'),
# ('access-control-allow-credentials', 'true'),
('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0'),
('Connection', 'keep-alive'),
('Vary', 'Origin'),
],
)
yield 'No.'
def ddpp_sockjs_info(environ, start_response):
print(environ)
host = environ['HTTP_HOST'].split(':')[0]
start_response(
'200 OK',
[
('Content-Type', 'application/json; charset=UTF-8'),
(
'Access-Control-Allow-Origin',
'%s://%s:3000' % (
environ['wsgi.url_scheme'],
environ['HTTP_HOST'].split(':')[0],
),
),
('Access-Control-Allow-Credentials', 'true'),
# ('access-control-allow-credentials', 'true'),
('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0'),
('Connection', 'keep-alive'),
('Vary', 'Origin'),
],
)
yield ejson.dumps(collections.OrderedDict([
('websocket', True),
('origins', [
'*:*',
]),
('cookie_needed', False),
('entropy', random.getrandbits(32)),
]))
class DDPServer(geventwebsocket.WebSocketServer):
def __init__(self, *args, **kwargs):
print('INIT: %r %r' % (args, kwargs))
return super(DDPServer, self).__init__(*args, **kwargs)
resource = geventwebsocket.Resource({
r'/websocket': DDPApplication,
r'^/sockjs/\d+/\w+/websocket$': DDPApplication,
r'^/sockjs/\d+/\w+/xhr$': ddpp_sockjs_xhr,
r'^/sockjs/info$': ddpp_sockjs_info,
})
if __name__ == '__main__':
addr = (sys.argv[1:] + [':8001'])[0]
(host, port) = (addr.rsplit(':', 1)[:2] + [':8001'])[:2]
if port.isdigit():
port = int(port)
else:
port = socket.getservbyname(port)
server = geventwebsocket.WebSocketServer(
(host, port),
resource,
debug='-v' in sys.argv,
)
print('Running as ws://%s:%d/websocket' % (host, port))
threads = [
gevent.spawn(server.serve_forever),
gevent.spawn(pg_listen),
]
def killall():
"""Kill all green threads."""
for thread in threads:
thread.kill()
gevent.signal(signal.SIGINT, killall)
gevent.signal(signal.SIGQUIT, killall)
gevent.joinall(threads)