Telethon/telethon/_misc/entitycache.py
2021-09-24 20:12:23 +02:00

180 lines
6.9 KiB
Python

import inspect
import itertools
from .._misc import utils
from .. import _tl
from .._sessions.types import Entity
# Which updates have the following fields?
_has_field = {
('user_id', int): [],
('chat_id', int): [],
('channel_id', int): [],
('peer', 'TypePeer'): [],
('peer', 'TypeDialogPeer'): [],
('message', 'TypeMessage'): [],
}
# Note: We don't bother checking for some rare:
# * `UpdateChatParticipantAdd.inviter_id` integer.
# * `UpdateNotifySettings.peer` dialog peer.
# * `UpdatePinnedDialogs.order` list of dialog peers.
# * `UpdateReadMessagesContents.messages` list of messages.
# * `UpdateChatParticipants.participants` list of participants.
#
# There are also some uninteresting `update.message` of type string.
def _fill():
for name in dir(_tl):
update = getattr(_tl, name)
if getattr(update, 'SUBCLASS_OF_ID', None) == 0x9f89304e:
cid = update.CONSTRUCTOR_ID
sig = inspect.signature(update.__init__)
for param in sig.parameters.values():
vec = _has_field.get((param.name, param.annotation))
if vec is not None:
vec.append(cid)
# Future-proof check: if the documentation format ever changes
# then we won't be able to pick the update types we are interested
# in, so we must make sure we have at least an update for each field
# which likely means we are doing it right.
if not all(_has_field.values()):
raise RuntimeError('FIXME: Did the init signature or updates change?')
# We use a function to avoid cluttering the globals (with name/update/cid/doc)
_fill()
class EntityCache:
"""
In-memory input entity cache, defaultdict-like behaviour.
"""
def add(self, entities, _mappings={
_tl.User.CONSTRUCTOR_ID: lambda e: (Entity.BOT if e.bot else Entity.USER, e.id, e.access_hash),
_tl.UserFull.CONSTRUCTOR_ID: lambda e: (Entity.BOT if e.user.bot else Entity.USER, e.user.id, e.user.access_hash),
_tl.Chat.CONSTRUCTOR_ID: lambda e: (Entity.GROUP, e.id, 0),
_tl.ChatFull.CONSTRUCTOR_ID: lambda e: (Entity.GROUP, e.id, 0),
_tl.ChatEmpty.CONSTRUCTOR_ID: lambda e: (Entity.GROUP, e.id, 0),
_tl.ChatForbidden.CONSTRUCTOR_ID: lambda e: (Entity.GROUP, e.id, 0),
_tl.Channel.CONSTRUCTOR_ID: lambda e: (
Entity.MEGAGROUP if e.megagroup else (Entity.GIGAGROUP if e.gigagroup else Entity.CHANNEL),
e.id,
e.access_hash,
),
_tl.ChannelForbidden.CONSTRUCTOR_ID: lambda e: (Entity.MEGAGROUP if e.megagroup else Entity.CHANNEL, e.id, e.access_hash),
}):
"""
Adds the given entities to the cache, if they weren't saved before.
Returns a list of Entity that can be saved in the session.
"""
if not utils.is_list_like(entities):
# Invariant: all "chats" and "users" are always iterables,
# and "user" and "chat" never are (so we wrap them inside a list).
#
# Itself may be already the entity we want to cache.
entities = itertools.chain(
[entities],
getattr(entities, 'chats', []),
getattr(entities, 'users', []),
(hasattr(entities, 'user') and [entities.user]) or [],
(hasattr(entities, 'chat') and [entities.user]) or [],
)
rows = []
for e in entities:
try:
mapper = _mappings[e.CONSTRUCTOR_ID]
except (AttributeError, KeyError):
continue
ty, id, access_hash = mapper(e)
# Need to check for non-zero access hash unless it's a group (#354 and #392).
# Also check it's not `min` (`access_hash` usage is limited since layer 102).
if not getattr(e, 'min', False) and (access_hash or ty == Entity.GROUP):
rows.append(Entity(ty, id, access_hash))
if id not in self.__dict__:
if ty in (Entity.USER, Entity.BOT):
self.__dict__[id] = _tl.InputPeerUser(id, access_hash)
elif ty in (Entity.GROUP,):
self.__dict__[id] = _tl.InputPeerChat(id)
elif ty in (Entity.CHANNEL, Entity.MEGAGROUP, Entity.GIGAGROUP):
self.__dict__[id] = _tl.InputPeerChannel(id, access_hash)
return rows
def __getitem__(self, item):
"""
Gets the corresponding :tl:`InputPeer` for the given ID or peer,
or raises ``KeyError`` on any error (i.e. cannot be found).
"""
if not isinstance(item, int) or item < 0:
try:
return self.__dict__[utils.get_peer_id(item)]
except TypeError:
raise KeyError('Invalid key will not have entity') from None
for cls in (_tl.PeerUser, _tl.PeerChat, _tl.PeerChannel):
result = self.__dict__.get(utils.get_peer_id(cls(item)))
if result:
return result
raise KeyError('No cached entity for the given key')
def clear(self):
"""
Clear the entity cache.
"""
self.__dict__.clear()
def ensure_cached(
self,
update,
has_user_id=frozenset(_has_field[('user_id', int)]),
has_chat_id=frozenset(_has_field[('chat_id', int)]),
has_channel_id=frozenset(_has_field[('channel_id', int)]),
has_peer=frozenset(_has_field[('peer', 'TypePeer')] + _has_field[('peer', 'TypeDialogPeer')]),
has_message=frozenset(_has_field[('message', 'TypeMessage')])
):
"""
Ensures that all the relevant entities in the given update are cached.
"""
# This method is called pretty often and we want it to have the lowest
# overhead possible. For that, we avoid `isinstance` and constantly
# getting attributes out of `_tl.` by "caching" the constructor IDs
# in sets inside the arguments, and using local variables.
dct = self.__dict__
cid = update.CONSTRUCTOR_ID
if cid in has_user_id and \
update.user_id not in dct:
return False
if cid in has_chat_id and update.chat_id not in dct:
return False
if cid in has_channel_id and update.channel_id not in dct:
return False
if cid in has_peer and \
utils.get_peer_id(update.peer) not in dct:
return False
if cid in has_message:
x = update.message
y = getattr(x, 'peer_id', None) # handle MessageEmpty
if y and utils.get_peer_id(y) not in dct:
return False
y = getattr(x, 'from_id', None)
if y and utils.get_peer_id(y) not in dct:
return False
# We don't quite worry about entities anywhere else.
# This is enough.
return True