576 lines
17 KiB
Python
576 lines
17 KiB
Python
import asyncio
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import secrets
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import logging
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import websockets
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import re
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from urllib.parse import urlparse, urlunparse
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log = logging.getLogger(__name__)
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import syndicate.mini.protocol as protocol
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import syndicate.mini.url as url
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from syndicate.mini.protocol import Capture, Discard, Observe
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CAPTURE = Capture(Discard())
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from preserves import *
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def _encode(event):
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e = protocol.Encoder()
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e.append(event)
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return e.contents()
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_instance_id = secrets.token_urlsafe(8)
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_uuid_counter = 0
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def uuid(prefix='__@syndicate'):
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global _uuid_counter
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c = _uuid_counter
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_uuid_counter = c + 1
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return prefix + '_' + _instance_id + '_' + str(c)
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def _ignore(*args, **kwargs):
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pass
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class Turn(object):
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def __init__(self, conn):
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self.conn = conn
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self.items = []
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def _ensure(self, what):
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if self.items is None:
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raise Exception('Attempt to %s a completed Turn' % (what,))
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def _extend(self, item):
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self._ensure('extend')
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self.items.append(item)
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def _reset(self):
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self._ensure('reset')
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self.items.clear()
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def _commit(self):
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self._ensure('commit')
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if self.items: self.conn._send(protocol.Turn(self.items))
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self.items = None
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def send(self, message):
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self._extend(protocol.Message(message))
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def merge_into(self, other):
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self._ensure('merge from')
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other._ensure('merge into')
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if self.items: other.items.extend(self.items)
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self.items.clear()
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def __enter__(self):
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return self
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def __exit__(self, t, v, tb):
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if t is None:
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self._commit()
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def _fresh_id(assertion):
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return uuid('sub' if Observe.isClassOf(assertion) else 'pub')
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class FacetSetupContext(object):
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def __init__(self, turn, facet):
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self.turn = turn
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self.facet = facet
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def __enter__(self):
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return self.facet
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def __exit__(self, t, v, tb):
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if t is None:
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self.facet.start(self.turn)
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else:
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self.facet.actor.kill(self.turn, (t, v, tb))
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_next_actor_number = 0
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def _next_actor_name():
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global _next_actor_number
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n = _next_actor_number
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_next_actor_number = n + 1
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return str(n)
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class Actor(object):
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def __init__(self, conn, name=None):
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self.conn = conn
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self.name = name or _next_actor_name()
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self.children = set()
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self.alive = True
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self._log = None
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@property
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def log(self):
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if self._log is None:
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self._log = logging.getLogger('syndicate.mini.Actor.%s' % (self.name,))
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return self._log
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def react(self, turn):
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return FacetSetupContext(turn, Facet(self.conn, self, self))
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def _add_child(self, facet):
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if not self.alive:
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raise Exception('Cannot add facet because actor is termianted')
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self.children.add(facet)
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def guard(self, turn):
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return ActorGuard(turn, self)
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def is_inert(self):
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return len(self.children) == 0
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def _stop(self, turn, pending, is_abort):
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for child in list(self.children):
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child._stop(turn, pending, is_abort)
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self.children.clear()
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def stop(self, turn):
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self.alive = False
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pending = []
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self._stop(turn, pending, False)
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for t in pending: t(turn)
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def kill(self, turn, exc_info):
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log.error('%r%s died', self, repr(self.name) if self.name else '', exc_info=exc_info)
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for child in list(self.children):
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child._abort(turn)
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self.children.clear()
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class ActorGuard(object):
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def __init__(self, turn, actor):
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self.turn = turn
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self.actor = actor
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def __enter__(self):
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pass
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def __exit__(self, t, v, tb):
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if t is not None:
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self.actor.kill(self.turn, (t, v, tb))
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return True ## suppress exception
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class Facet(object):
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def __init__(self, conn, actor, parent):
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self.conn = conn
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self.actor = actor
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self.parent = parent
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if parent:
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parent._add_child(self)
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self.children = set()
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self.start_callbacks = []
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self.stop_callbacks = []
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self.endpoints = []
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self.state = 0
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@property
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def log(self):
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return self.actor.log
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def _ensure_state(self, wanted_state, message):
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if self.state != wanted_state:
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raise Exception(message)
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def _add_child(self, facet):
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self._ensure_state(1, 'Cannot add child facet in this state')
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self.children.add(facet)
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def react(self, turn):
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self._ensure_state(1, 'Cannot create subfacet in this state')
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return FacetSetupContext(turn, Facet(self.conn, self.actor, self))
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def add(self, *args, **kwargs):
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self._ensure_state(0, 'Cannot add endpoint to facet in this state')
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endpoint = Endpoint(self, *args, **kwargs)
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self.endpoints.append(endpoint)
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return endpoint
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def on_start(self, callback):
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self._ensure_state(0, 'Cannot add on_start callback to facet in this state')
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self.start_callbacks.append(callback)
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def on_stop(self, callback):
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self._ensure_state(0, 'Cannot add on_stop callback to facet in this state')
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self.stop_callbacks.append(callback)
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def start(self, turn):
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self._ensure_state(0, 'Cannot start facet in this state')
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self.state = 1
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for e in self.endpoints: e._start(turn)
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for t in self.start_callbacks: t(turn)
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self.start_callbacks.clear()
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def is_inert(self):
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return len(self.children) == 0 and len(self.endpoints) == 0
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def _stop(self, turn, pending, is_abort):
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if turn.conn is not self.conn:
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raise Exception('Attempted to stop facet from wrong connection')
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if self.state == 0 and not is_abort:
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raise Exception('Cannot stop facet before starting it')
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if self.state != 1: ## stopping is idempotent
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return
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self.state = 2
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if self.parent:
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self.parent.children.remove(self)
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for child in list(self.children):
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child._stop(turn, pending, is_abort)
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self.children.clear()
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if not is_abort:
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pending.extend(self.stop_callbacks)
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for endpoint in self.endpoints:
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endpoint.clear(turn)
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self.endpoints.clear()
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if not is_abort:
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if self.parent and self.parent.is_inert():
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self.parent._stop(turn, pending, is_abort)
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def stop(self, turn):
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pending = []
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self._stop(turn, pending, False)
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for t in pending: t(turn)
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def _abort(self, turn):
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self._stop(turn, None, True)
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class Endpoint(object):
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def __init__(self, facet, assertion, on_add=None, on_del=None, on_msg=None):
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self.facet = facet
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self.assertion = assertion
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self.id = None
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self.on_add = on_add or _ignore
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self.on_del = on_del or _ignore
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self.on_msg = on_msg or _ignore
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self.cache = set()
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@property
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def log(self):
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return self.facet.log
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def _start(self, turn):
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self.set(turn, self.assertion)
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def set(self, turn, new_assertion, on_transition=None):
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if self.id is not None:
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turn.conn._unmap_endpoint(turn, self, on_end=on_transition)
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self.id = None
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self.assertion = new_assertion
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if self.assertion is not None:
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self.id = _fresh_id(self.assertion)
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turn.conn._map_endpoint(turn, self)
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def clear(self, turn, on_cleared=None):
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self.set(turn, None, on_transition=on_cleared)
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def _reset(self, turn):
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for captures in set(self.cache):
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self._del(turn, captures)
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def _add(self, turn, captures):
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if captures in self.cache:
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log.error('Server error: duplicate captures %r added for endpoint %r %r' % (
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captures,
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self.id,
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self.assertion))
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else:
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self.cache.add(captures)
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with self.facet.actor.guard(turn):
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self.on_add(turn, *captures)
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def _del(self, turn, captures):
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if captures in self.cache:
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self.cache.discard(captures)
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with self.facet.actor.guard(turn):
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self.on_del(turn, *captures)
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else:
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log.error('Server error: nonexistent captures %r removed from endpoint %r %r' % (
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captures,
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self.id,
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self.assertion))
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def _msg(self, turn, captures):
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with self.facet.actor.guard(turn):
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self.on_msg(turn, *captures)
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class DummyEndpoint(object):
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def _add(self, turn, captures): pass
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def _del(self, turn, captures): pass
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def _msg(self, turn, captures): pass
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_dummy_endpoint = DummyEndpoint()
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class Connection(object):
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def __init__(self, scope):
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self.scope = scope
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self.endpoints = {}
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self.end_callbacks = {}
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self._is_connected = False
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def is_connected(self):
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return self._is_connected
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def _each_endpoint(self):
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return list(self.endpoints.values())
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def turn(self):
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return Turn(self)
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def actor(self, name=None):
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return Actor(self, name=name)
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def destroy(self):
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with self.turn() as t:
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for ep in self._each_endpoint():
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ep.clear(t)
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t._reset() ## don't actually Clear the endpoints, we are about to disconnect
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self._disconnect()
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def _unmap_endpoint(self, turn, ep, on_end=None):
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del self.endpoints[ep.id]
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if on_end:
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self.end_callbacks[ep.id] = on_end
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turn._extend(protocol.Clear(ep.id))
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def _on_end(self, turn, id):
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if id in self.end_callbacks:
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self.end_callbacks[id](turn)
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del self.end_callbacks[id]
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def _map_endpoint(self, turn, ep):
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self.endpoints[ep.id] = ep
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turn._extend(protocol.Assert(ep.id, ep.assertion))
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def _on_disconnected(self):
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self._is_connected = False
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with self.turn() as t:
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for ep in self._each_endpoint():
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ep._reset(t)
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t._reset() ## we have been disconnected, no point in keeping the actions
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self._disconnect()
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def _on_connected(self):
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self._send(protocol.Connect(self.scope))
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with self.turn() as t:
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for ep in self._each_endpoint():
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self._map_endpoint(t, ep)
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self._is_connected = True
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def _lookup(self, endpointId):
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return self.endpoints.get(endpointId, _dummy_endpoint)
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def _on_event(self, v):
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with self.turn() as t:
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self._handle_event(t, v)
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def _handle_event(self, turn, v):
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if protocol.Turn.isClassOf(v):
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for item in protocol.Turn._items(v):
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if protocol.Add.isClassOf(item): self._lookup(item[0])._add(turn, item[1])
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elif protocol.Del.isClassOf(item): self._lookup(item[0])._del(turn, item[1])
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elif protocol.Msg.isClassOf(item): self._lookup(item[0])._msg(turn, item[1])
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elif protocol.End.isClassOf(item): self._on_end(turn, item[0])
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else: log.error('Unhandled server Turn item: %r' % (item,))
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return
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elif protocol.Err.isClassOf(v):
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self._on_error(v[0], v[1])
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return
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elif protocol.Ping.isClassOf(v):
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self._send_bytes(_encode(protocol.Pong()))
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return
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else:
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log.error('Unhandled server message: %r' % (v,))
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def _on_error(self, detail, context):
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log.error('%s: error from server: %r (context: %r)' % (
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self.__class__.__qualname__, detail, context))
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self._disconnect()
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def _send(self, m):
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return self._send_bytes(_encode(m))
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def _send_bytes(self, bs, commitNeeded = False):
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raise Exception('subclassresponsibility')
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def _disconnect(self):
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raise Exception('subclassresponsibility')
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async def reconnecting_main(self, loop, on_connected=None, on_disconnected=None):
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should_run = True
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while should_run:
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did_connect = await self.main(loop, on_connected=(on_connected or _default_on_connected))
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should_run = await (on_disconnected or _default_on_disconnected)(did_connect)
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@classmethod
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def from_url(cls, s):
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return url.connection_from_url(s)
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async def _default_on_connected():
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log.info('Connected')
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async def _default_on_disconnected(did_connect):
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if did_connect:
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# Reconnect immediately
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log.info('Disconnected')
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else:
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await asyncio.sleep(2)
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return True
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class _StreamConnection(Connection, asyncio.Protocol):
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def __init__(self, scope):
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super().__init__(scope)
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self.decoder = None
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self.stop_signal = None
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self.transport = None
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def connection_lost(self, exc):
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self._on_disconnected()
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def connection_made(self, transport):
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self.transport = transport
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self._on_connected()
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def data_received(self, chunk):
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self.decoder.extend(chunk)
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while True:
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v = self.decoder.try_next()
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if v is None: break
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self._on_event(v)
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def _send_bytes(self, bs, commitNeeded = False):
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if self.transport:
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self.transport.write(bs)
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if commitNeeded:
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self.commitNeeded = True
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def _disconnect(self):
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if self.stop_signal:
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self.stop_signal.get_loop().call_soon_threadsafe(
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lambda: self.stop_signal.set_result(True))
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async def _create_connection(self, loop):
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raise Exception('subclassresponsibility')
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async def main(self, loop, on_connected=None):
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if self.transport is not None:
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raise Exception('Cannot run connection twice!')
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self.decoder = protocol.Decoder()
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self.stop_signal = loop.create_future()
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try:
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_transport, _protocol = await self._create_connection(loop)
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except OSError as e:
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log.error('%s: Could not connect to server: %s' % (self.__class__.__qualname__, e))
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return False
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try:
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if on_connected: await on_connected()
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await self.stop_signal
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return True
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finally:
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self.transport.close()
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self.transport = None
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self.stop_signal = None
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self.decoder = None
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@url.schema('tcp')
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class TcpConnection(_StreamConnection):
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def __init__(self, host, port, scope):
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super().__init__(scope)
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self.host = host
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self.port = port
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async def _create_connection(self, loop):
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return await loop.create_connection(lambda: self, self.host, self.port)
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@classmethod
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def default_port(cls):
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return 21369
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@classmethod
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def from_url(cls, s):
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u = urlparse(s)
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host, port = url._hostport(u.netloc, cls.default_port())
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if not host: return
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scope = u.fragment
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return cls(host, port, scope)
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@url.schema('unix')
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class UnixSocketConnection(_StreamConnection):
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def __init__(self, path, scope):
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super().__init__(scope)
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self.path = path
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async def _create_connection(self, loop):
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return await loop.create_unix_connection(lambda: self, self.path)
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@classmethod
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def from_url(cls, s):
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u = urlparse(s)
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return cls(u.path, u.fragment)
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@url.schema('ws')
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@url.schema('wss')
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class WebsocketConnection(Connection):
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def __init__(self, url, scope):
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super().__init__(scope)
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self.url = url
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self.loop = None
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self.ws = None
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def _send_bytes(self, bs, commitNeeded = False):
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if self.loop:
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def _do_send():
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if self.ws:
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self.loop.create_task(self.ws.send(bs))
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self.loop.call_soon_threadsafe(_do_send)
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if commitNeeded:
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self.commitNeeded = True
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def _disconnect(self):
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if self.loop:
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def _do_disconnect():
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if self.ws:
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self.loop.create_task(self.ws.close())
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self.loop.call_soon_threadsafe(_do_disconnect)
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async def main(self, loop, on_connected=None):
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if self.ws is not None:
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raise Exception('Cannot run connection twice!')
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self.loop = loop
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|
try:
|
|
async with websockets.connect(self.url) as ws:
|
|
if on_connected: await on_connected()
|
|
self.ws = ws
|
|
self._on_connected()
|
|
try:
|
|
while True:
|
|
chunk = await ws.recv()
|
|
self._on_event(protocol.Decoder(chunk).next())
|
|
except websockets.exceptions.ConnectionClosed:
|
|
pass
|
|
except OSError as e:
|
|
log.error('%s: Could not connect to server: %s' % (self.__class__.__qualname__, e))
|
|
return False
|
|
finally:
|
|
self._on_disconnected()
|
|
|
|
if self.ws:
|
|
await self.ws.close()
|
|
self.loop = None
|
|
self.ws = None
|
|
return True
|
|
|
|
@classmethod
|
|
def from_url(cls, s):
|
|
u = urlparse(s)
|
|
return cls(urlunparse(u._replace(fragment='')), u.fragment)
|