Telethon/telethon/update_state.py
2017-09-22 23:14:31 +02:00

91 lines
2.9 KiB
Python

from collections import deque
from datetime import datetime
from threading import RLock, Event
from .tl import types as tl
class UpdateState:
"""Used to hold the current state of processed updates.
To retrieve an update, .poll() should be called.
"""
def __init__(self, polling):
self._polling = polling
self.handlers = []
self._updates_lock = RLock()
self._updates_available = Event()
self._updates = deque()
# https://core.telegram.org/api/updates
self._state = tl.updates.State(0, 0, datetime.now(), 0, 0)
def can_poll(self):
"""Returns True if a call to .poll() won't lock"""
return self._updates_available.is_set()
def poll(self):
"""Polls an update or blocks until an update object is available"""
if not self._polling:
raise ValueError('Updates are not being polled hence not saved.')
self._updates_available.wait()
with self._updates_lock:
update = self._updates.popleft()
if not self._updates:
self._updates_available.clear()
if isinstance(update, Exception):
raise update # Some error was set through .set_error()
return update
def get_polling(self):
return self._polling
def set_polling(self, polling):
self._polling = polling
if not polling:
with self._updates_lock:
self._updates.clear()
polling = property(fget=get_polling, fset=set_polling)
def set_error(self, error):
"""Sets an error, so that the next call to .poll() will raise it.
Can be (and is) used to pass exceptions between threads.
"""
with self._updates_lock:
# Insert at the beginning so the very next poll causes an error
# TODO Should this reset the pts and such?
self._updates.insert(0, error)
self._updates_available.set()
def check_error(self):
with self._updates_lock:
if self._updates and isinstance(self._updates[0], Exception):
raise self._updates.pop()
def process(self, update):
"""Processes an update object. This method is normally called by
the library itself.
"""
if not self._polling and not self.handlers:
return
with self._updates_lock:
if isinstance(update, tl.updates.State):
self._state = update
return # Nothing else to be done
pts = getattr(update, 'pts', self._state.pts)
if hasattr(update, 'pts') and pts <= self._state.pts:
return # We already handled this update
self._state.pts = pts
if self._polling:
self._updates.append(update)
self._updates_available.set()
for handler in self.handlers:
handler(update)