socketIO-client/socketIO_client/__init__.py
2015-02-16 14:23:46 -05:00

522 lines
18 KiB
Python

import logging
import json
import requests
import time
from collections import namedtuple
try:
from urllib.parse import urlparse as parse_url
except ImportError:
from urlparse import urlparse as parse_url
from .exceptions import (
SocketIOError, ConnectionError, TimeoutError, PacketError)
from .transports import (
_get_response, TRANSPORTS,
_WebsocketTransport, _XHR_PollingTransport, _JSONP_PollingTransport)
__version__ = '0.5.4'
_SocketIOSession = namedtuple('_SocketIOSession', [
'id',
'heartbeat_timeout',
'server_supported_transports',
])
_log = logging.getLogger(__name__)
PROTOCOL_VERSION = 1
RETRY_INTERVAL_IN_SECONDS = 1
class BaseNamespace(object):
'Define client behavior'
def __init__(self, _transport, path):
self._transport = _transport
self.path = path
self._was_connected = False
self._callback_by_event = {}
self.initialize()
def initialize(self):
'Initialize custom variables here; you can override this method'
pass
def message(self, data='', callback=None):
self._transport.message(self.path, data, callback)
def emit(self, event, *args, **kw):
callback, args = find_callback(args, kw)
self._transport.emit(self.path, event, args, callback)
def disconnect(self):
self._transport.disconnect(self.path)
def on(self, event, callback):
'Define a callback to handle a custom event emitted by the server'
self._callback_by_event[event] = callback
def on_connect(self):
'Called after server connects; you can override this method'
pass
def on_disconnect(self):
'Called after server disconnects; you can override this method'
pass
def on_heartbeat(self):
'Called after server sends a heartbeat; you can override this method'
pass
def on_message(self, data):
'Called after server sends a message; you can override this method'
pass
def on_event(self, event, *args):
"""
Called after server sends an event; you can override this method.
Called only if a custom event handler does not exist,
such as one defined by namespace.on('my_event', my_function).
"""
callback, args = find_callback(args)
if callback:
callback(*args)
def on_error(self, reason, advice):
'Called after server sends an error; you can override this method'
pass
def on_noop(self):
'Called after server sends a noop; you can override this method'
pass
def on_open(self, *args):
pass
def on_close(self, *args):
pass
def on_retry(self, *args):
pass
def on_reconnect(self, *args):
pass
def _find_event_callback(self, event):
# Check callbacks defined by on()
try:
return self._callback_by_event[event]
except KeyError:
pass
# Convert connect to reconnect if we have seen connect already
if event == 'connect':
if not self._was_connected:
self._was_connected = True
else:
event = 'reconnect'
# Check callbacks defined explicitly or use on_event()
return getattr(
self,
'on_' + event.replace(' ', '_'),
lambda *args: self.on_event(event, *args))
class LoggingNamespace(BaseNamespace):
def _log(self, level, msg, *attrs):
_log.log(level, '%s: %s' % (self._transport._url, msg), *attrs)
def on_connect(self):
self._log(logging.DEBUG, '%s [connect]', self.path)
super(LoggingNamespace, self).on_connect()
def on_disconnect(self):
self._log(logging.DEBUG, '%s [disconnect]', self.path)
super(LoggingNamespace, self).on_disconnect()
def on_heartbeat(self):
self._log(logging.DEBUG, '%s [heartbeat]', self.path)
super(LoggingNamespace, self).on_heartbeat()
def on_message(self, data):
self._log(logging.INFO, '%s [message] %s', self.path, data)
super(LoggingNamespace, self).on_message(data)
def on_event(self, event, *args):
callback, args = find_callback(args)
arguments = [repr(_) for _ in args]
if callback:
arguments.append('callback(*args)')
self._log(logging.INFO, '%s [event] %s(%s)', self.path, event,
', '.join(arguments))
super(LoggingNamespace, self).on_event(event, *args)
def on_error(self, reason, advice):
self._log(logging.INFO, '%s [error] %s', self.path, advice)
super(LoggingNamespace, self).on_error(reason, advice)
def on_noop(self):
self._log(logging.INFO, '%s [noop]', self.path)
super(LoggingNamespace, self).on_noop()
def on_open(self, *args):
self._log(logging.INFO, '%s [open] %s', self.path, args)
super(LoggingNamespace, self).on_open(*args)
def on_close(self, *args):
self._log(logging.INFO, '%s [close] %s', self.path, args)
super(LoggingNamespace, self).on_close(*args)
def on_retry(self, *args):
self._log(logging.INFO, '%s [retry] %s', self.path, args)
super(LoggingNamespace, self).on_retry(*args)
def on_reconnect(self, *args):
self._log(logging.INFO, '%s [reconnect] %s', self.path, args)
super(LoggingNamespace, self).on_reconnect(*args)
class SocketIO(object):
"""Create a socket.io client that connects to a socket.io server
at the specified host and port.
- Define the behavior of the client by specifying a custom Namespace.
- Prefix host with https:// to use SSL.
- Set wait_for_connection=True to block until we have a connection.
- Specify desired transports=['websocket', 'xhr-polling'].
- Pass query params, headers, cookies, proxies as keyword arguments.
SocketIO('localhost', 8000,
params={'q': 'qqq'},
headers={'Authorization': 'Basic ' + b64encode('username:password')},
cookies={'a': 'aaa'},
proxies={'https': 'https://proxy.example.com:8080'})
"""
def __init__(
self, host, port=None, Namespace=None,
wait_for_connection=True, transports=TRANSPORTS,
resource='socket.io', **kw):
self.is_secure, self._base_url = _parse_host(host, port, resource)
self.wait_for_connection = wait_for_connection
self._namespace_by_path = {}
self._client_supported_transports = transports
self._kw = kw
if Namespace:
self.define(Namespace)
def _log(self, level, msg, *attrs):
_log.log(level, '%s: %s' % (self._base_url, msg), *attrs)
def __enter__(self):
return self
def __exit__(self, *exception_pack):
self.disconnect()
def __del__(self):
self.disconnect()
def define(self, Namespace, path=''):
if path:
self._transport.connect(path)
namespace = Namespace(self._transport, path)
self._namespace_by_path[path] = namespace
return namespace
def on(self, event, callback, path=''):
if path not in self._namespace_by_path:
self.define(BaseNamespace, path)
return self.get_namespace(path).on(event, callback)
def message(self, data='', callback=None, path=''):
self._transport.message(path, data, callback)
def emit(self, event, *args, **kw):
path = kw.get('path', '')
callback, args = find_callback(args, kw)
self._transport.emit(path, event, args, callback)
def wait(self, seconds=None, for_callbacks=False):
"""Wait in a loop and process events as defined in the namespaces.
- Omit seconds, i.e. call wait() without arguments, to wait forever.
"""
warning_screen = _yield_warning_screen(seconds)
timeout = min(self._heartbeat_interval, seconds)
for elapsed_time in warning_screen:
if self._stop_waiting(for_callbacks):
break
try:
try:
self._process_events(timeout)
except TimeoutError:
pass
next(self._heartbeat_pacemaker)
except ConnectionError as e:
try:
warning = Exception('[connection error] %s' % e)
warning_screen.throw(warning)
except StopIteration:
self._log(logging.WARNING, warning)
try:
namespace = self._namespace_by_path['']
namespace.on_disconnect()
except KeyError:
pass
def _process_events(self, timeout=None):
for packet in self._transport.recv_packet(timeout):
try:
self._process_packet(packet)
except PacketError as e:
self._log(logging.WARNING, '[packet error] %s', e)
def _process_packet(self, packet):
code, packet_id, path, data = packet
namespace = self.get_namespace(path)
delegate = self._get_delegate(code)
delegate(packet, namespace._find_event_callback)
def _stop_waiting(self, for_callbacks):
# Use __transport to make sure that we do not reconnect inadvertently
if for_callbacks and not self.__transport.has_ack_callback:
return True
if self.__transport._wants_to_disconnect:
return True
return False
def wait_for_callbacks(self, seconds=None):
self.wait(seconds, for_callbacks=True)
def disconnect(self, path=''):
try:
self._transport.disconnect(path)
except ReferenceError:
pass
try:
namespace = self._namespace_by_path[path]
namespace.on_disconnect()
del self._namespace_by_path[path]
except KeyError:
pass
@property
def connected(self):
try:
transport = self.__transport
except AttributeError:
return False
else:
return transport.connected
@property
def _transport(self):
try:
if self.connected:
return self.__transport
except AttributeError:
pass
socketIO_session = self._get_socketIO_session()
supported_transports = self._get_supported_transports(socketIO_session)
self._heartbeat_pacemaker = self._make_heartbeat_pacemaker(
heartbeat_timeout=socketIO_session.heartbeat_timeout)
next(self._heartbeat_pacemaker)
warning_screen = _yield_warning_screen(seconds=None)
for elapsed_time in warning_screen:
try:
self._transport_name = supported_transports.pop(0)
except IndexError:
raise ConnectionError('Could not negotiate a transport')
try:
self.__transport = self._get_transport(
socketIO_session, self._transport_name)
break
except ConnectionError:
pass
for path, namespace in self._namespace_by_path.items():
namespace._transport = self.__transport
if path:
self.__transport.connect(path)
return self.__transport
def _get_socketIO_session(self):
warning_screen = _yield_warning_screen(seconds=None)
for elapsed_time in warning_screen:
try:
return _get_socketIO_session(
self.is_secure, self._base_url, **self._kw)
except ConnectionError as e:
if not self.wait_for_connection:
raise
warning = Exception('[waiting for connection] %s' % e)
try:
warning_screen.throw(warning)
except StopIteration:
self._log(logging.WARNING, warning)
def _get_supported_transports(self, session):
self._log(
logging.DEBUG, '[transports available] %s',
' '.join(session.server_supported_transports))
supported_transports = [
x for x in self._client_supported_transports if
x in session.server_supported_transports]
if not supported_transports:
raise SocketIOError(' '.join([
'could not negotiate a transport:',
'client supports %s but' % ', '.join(
self._client_supported_transports),
'server supports %s' % ', '.join(
session.server_supported_transports),
]))
return supported_transports
def _get_transport(self, session, transport_name):
self._log(logging.DEBUG, '[transport chosen] %s', transport_name)
return {
'websocket': _WebsocketTransport,
'xhr-polling': _XHR_PollingTransport,
'jsonp-polling': _JSONP_PollingTransport,
}[transport_name](session, self.is_secure, self._base_url, **self._kw)
def _make_heartbeat_pacemaker(self, heartbeat_timeout):
self._heartbeat_interval = heartbeat_timeout / 2
heartbeat_time = time.time()
while True:
yield
if time.time() - heartbeat_time > self._heartbeat_interval:
heartbeat_time = time.time()
self._transport.send_heartbeat()
def get_namespace(self, path=''):
try:
return self._namespace_by_path[path]
except KeyError:
raise PacketError('unhandled namespace path (%s)' % path)
def _get_delegate(self, code):
try:
return {
'0': self._on_disconnect,
'1': self._on_connect,
'2': self._on_heartbeat,
'3': self._on_message,
'4': self._on_json,
'5': self._on_event,
'6': self._on_ack,
'7': self._on_error,
'8': self._on_noop,
}[code]
except KeyError:
raise PacketError('unexpected code (%s)' % code)
def _on_disconnect(self, packet, find_event_callback):
find_event_callback('disconnect')()
def _on_connect(self, packet, find_event_callback):
find_event_callback('connect')()
def _on_heartbeat(self, packet, find_event_callback):
find_event_callback('heartbeat')()
def _on_message(self, packet, find_event_callback):
code, packet_id, path, data = packet
args = [data]
if packet_id:
args.append(self._prepare_to_send_ack(path, packet_id))
find_event_callback('message')(*args)
def _on_json(self, packet, find_event_callback):
code, packet_id, path, data = packet
args = [json.loads(data)]
if packet_id:
args.append(self._prepare_to_send_ack(path, packet_id))
find_event_callback('message')(*args)
def _on_event(self, packet, find_event_callback):
code, packet_id, path, data = packet
value_by_name = json.loads(data)
event = value_by_name['name']
args = value_by_name.get('args', [])
if packet_id:
args.append(self._prepare_to_send_ack(path, packet_id))
find_event_callback(event)(*args)
def _on_ack(self, packet, find_event_callback):
code, packet_id, path, data = packet
data_parts = data.split('+', 1)
packet_id = data_parts[0]
try:
ack_callback = self._transport.get_ack_callback(packet_id)
except KeyError:
return
args = json.loads(data_parts[1]) if len(data_parts) > 1 else []
ack_callback(*args)
def _on_error(self, packet, find_event_callback):
code, packet_id, path, data = packet
reason, advice = data.split('+', 1)
find_event_callback('error')(reason, advice)
def _on_noop(self, packet, find_event_callback):
find_event_callback('noop')()
def _prepare_to_send_ack(self, path, packet_id):
'Return function that acknowledges the server'
return lambda *args: self._transport.ack(path, packet_id, *args)
def find_callback(args, kw=None):
'Return callback whether passed as a last argument or as a keyword'
if args and callable(args[-1]):
return args[-1], args[:-1]
try:
return kw['callback'], args
except (KeyError, TypeError):
return None, args
def _parse_host(host, port, resource):
if not host.startswith('http'):
host = 'http://' + host
url_pack = parse_url(host)
is_secure = url_pack.scheme == 'https'
port = port or url_pack.port or (443 if is_secure else 80)
base_url = '%s:%d%s/%s/%s' % (
url_pack.hostname, port, url_pack.path, resource, PROTOCOL_VERSION)
return is_secure, base_url
def _yield_warning_screen(seconds=None):
last_warning = None
for elapsed_time in _yield_elapsed_time(seconds):
try:
yield elapsed_time
except Exception as warning:
warning = str(warning)
if last_warning != warning:
last_warning = warning
_log.warn(warning)
time.sleep(RETRY_INTERVAL_IN_SECONDS)
def _yield_elapsed_time(seconds=None):
start_time = time.time()
if seconds is None:
while True:
yield time.time() - start_time
while time.time() - start_time < seconds:
yield time.time() - start_time
def _get_socketIO_session(is_secure, base_url, **kw):
server_url = '%s://%s/' % ('https' if is_secure else 'http', base_url)
try:
response = _get_response(requests.get, server_url, **kw)
except TimeoutError as e:
raise ConnectionError(e)
response_parts = response.text.split(':')
return _SocketIOSession(
id=response_parts[0],
heartbeat_timeout=int(response_parts[1]),
server_supported_transports=response_parts[3].split(','))