Reduce autocast overhead as much as possible

Rationale: if the user is doing things right, the penalty for
being friendly (i.e. autocasting to the right version, like
User -> InputPeerUser), should be as little as possible.

Removing the redundant type() call to access .SUBCLASS_OF_ID
and assuming the user provided a TLObject (through excepting
whenever the attribute is not available) is x2 and x4 times
faster respectively.

Of course, this is a micro-optimization, but I still consider
it's good to benefit users doing things right or avoiding
redundant calls.

telethon/telegram_client.py

@@ -818,10 +818,12 @@ def _get_reply_to(reply_to):
         if isinstance(reply_to, int):
             return reply_to
 
-        if isinstance(reply_to, TLObject) and \
-                        type(reply_to).SUBCLASS_OF_ID == 0x790009e3:
-            # hex(crc32(b'Message')) = 0x790009e3
-            return reply_to.id
+        try:
+            if reply_to.SUBCLASS_OF_ID == 0x790009e3:
+                # hex(crc32(b'Message')) = 0x790009e3
+                return reply_to.id
+        except AttributeError:
+            pass
 
         raise TypeError('Invalid reply_to type: {}'.format(type(reply_to)))
 
@@ -1191,9 +1193,14 @@ def download_profile_photo(self, entity, file=None, download_big=True):
         """
         photo = entity
         possible_names = []
-        if not isinstance(entity, TLObject) or type(entity).SUBCLASS_OF_ID in (
+        try:
+            is_entity = entity.SUBCLASS_OF_ID in (
                 0x2da17977, 0xc5af5d94, 0x1f4661b9, 0xd49a2697
-        ):
+            )
+        except AttributeError:
+            return None  # Not even a TLObject as attribute access failed
+
+        if is_entity:
             # Maybe it is an user or a chat? Or their full versions?
             #
             # The hexadecimal numbers above are simply:
@@ -1705,14 +1712,13 @@ def get_input_entity(self, peer):
         if isinstance(peer, int):
             peer = PeerUser(peer)
             is_peer = True
-
-        elif isinstance(peer, TLObject):
-            is_peer = type(peer).SUBCLASS_OF_ID == 0x2d45687  # crc32(b'Peer')
-            if not is_peer:
-                try:
+        else:
+            try:
+                is_peer = peer.SUBCLASS_OF_ID == 0x2d45687  # crc32(b'Peer')
+                if not is_peer:
                     return utils.get_input_peer(peer)
-                except TypeError:
-                    pass
+            except (AttributeError, TypeError):
+                pass  # Attribute if not TLObject, Type if not "casteable"
 
         if not is_peer:
             raise TypeError(

telethon/utils.py

@@ -3,11 +3,9 @@
 to convert between an entity like an User, Chat, etc. into its Input version)
 """
 import math
-from mimetypes import add_type, guess_extension
-
 import re
+from mimetypes import add_type, guess_extension
 
-from .tl import TLObject
 from .tl.types import (
     Channel, ChannelForbidden, Chat, ChatEmpty, ChatForbidden, ChatFull,
     ChatPhoto, InputPeerChannel, InputPeerChat, InputPeerUser, InputPeerEmpty,
@@ -25,7 +23,6 @@
     InputMediaUploadedPhoto, DocumentAttributeFilename, photos
 )
 
-
 USERNAME_RE = re.compile(
     r'@|(?:https?://)?(?:telegram\.(?:me|dog)|t\.me)/(joinchat/)?'
 )
@@ -81,12 +78,12 @@ def _raise_cast_fail(entity, target):
 def get_input_peer(entity, allow_self=True):
     """Gets the input peer for the given "entity" (user, chat or channel).
        A TypeError is raised if the given entity isn't a supported type."""
-    if not isinstance(entity, TLObject):
+    try:
+        if entity.SUBCLASS_OF_ID == 0xc91c90b6:  # crc32(b'InputPeer')
+            return entity
+    except AttributeError:
         _raise_cast_fail(entity, 'InputPeer')
 
-    if type(entity).SUBCLASS_OF_ID == 0xc91c90b6:  # crc32(b'InputPeer')
-        return entity
-
     if isinstance(entity, User):
         if entity.is_self and allow_self:
             return InputPeerSelf()
@@ -123,12 +120,12 @@ def get_input_peer(entity, allow_self=True):
 
 def get_input_channel(entity):
     """Similar to get_input_peer, but for InputChannel's alone"""
-    if not isinstance(entity, TLObject):
+    try:
+        if entity.SUBCLASS_OF_ID == 0x40f202fd:  # crc32(b'InputChannel')
+            return entity
+    except AttributeError:
         _raise_cast_fail(entity, 'InputChannel')
 
-    if type(entity).SUBCLASS_OF_ID == 0x40f202fd:  # crc32(b'InputChannel')
-        return entity
-
     if isinstance(entity, (Channel, ChannelForbidden)):
         return InputChannel(entity.id, entity.access_hash or 0)
 
@@ -140,12 +137,12 @@ def get_input_channel(entity):
 
 def get_input_user(entity):
     """Similar to get_input_peer, but for InputUser's alone"""
-    if not isinstance(entity, TLObject):
+    try:
+        if entity.SUBCLASS_OF_ID == 0xe669bf46:  # crc32(b'InputUser'):
+            return entity
+    except AttributeError:
         _raise_cast_fail(entity, 'InputUser')
 
-    if type(entity).SUBCLASS_OF_ID == 0xe669bf46:  # crc32(b'InputUser')
-        return entity
-
     if isinstance(entity, User):
         if entity.is_self:
             return InputUserSelf()
@@ -169,12 +166,12 @@ def get_input_user(entity):
 
 def get_input_document(document):
     """Similar to get_input_peer, but for documents"""
-    if not isinstance(document, TLObject):
+    try:
+        if document.SUBCLASS_OF_ID == 0xf33fdb68:  # crc32(b'InputDocument'):
+            return document
+    except AttributeError:
         _raise_cast_fail(document, 'InputDocument')
 
-    if type(document).SUBCLASS_OF_ID == 0xf33fdb68:  # crc32(b'InputDocument')
-        return document
-
     if isinstance(document, Document):
         return InputDocument(id=document.id, access_hash=document.access_hash)
 
@@ -192,12 +189,12 @@ def get_input_document(document):
 
 def get_input_photo(photo):
     """Similar to get_input_peer, but for documents"""
-    if not isinstance(photo, TLObject):
+    try:
+        if photo.SUBCLASS_OF_ID == 0x846363e0:  # crc32(b'InputPhoto'):
+            return photo
+    except AttributeError:
         _raise_cast_fail(photo, 'InputPhoto')
 
-    if type(photo).SUBCLASS_OF_ID == 0x846363e0:  # crc32(b'InputPhoto')
-        return photo
-
     if isinstance(photo, photos.Photo):
         photo = photo.photo
 
@@ -212,12 +209,12 @@ def get_input_photo(photo):
 
 def get_input_geo(geo):
     """Similar to get_input_peer, but for geo points"""
-    if not isinstance(geo, TLObject):
+    try:
+        if geo.SUBCLASS_OF_ID == 0x430d225:  # crc32(b'InputGeoPoint'):
+            return geo
+    except AttributeError:
         _raise_cast_fail(geo, 'InputGeoPoint')
 
-    if type(geo).SUBCLASS_OF_ID == 0x430d225:  # crc32(b'InputGeoPoint')
-        return geo
-
     if isinstance(geo, GeoPoint):
         return InputGeoPoint(lat=geo.lat, long=geo.long)
 
@@ -239,12 +236,12 @@ def get_input_media(media, user_caption=None, is_photo=False):
        If the media is a file location and is_photo is known to be True,
        it will be treated as an InputMediaUploadedPhoto.
     """
-    if not isinstance(media, TLObject):
+    try:
+        if media.SUBCLASS_OF_ID == 0xfaf846f4:  # crc32(b'InputMedia'):
+            return media
+    except AttributeError:
         _raise_cast_fail(media, 'InputMedia')
 
-    if type(media).SUBCLASS_OF_ID == 0xfaf846f4:  # crc32(b'InputMedia')
-        return media
-
     if isinstance(media, MessageMediaPhoto):
         return InputMediaPhoto(
             id=get_input_photo(media.photo),
@@ -357,15 +354,15 @@ def get_peer_id(peer):
     a call to utils.resolve_id(marked_id).
     """
     # First we assert it's a Peer TLObject, or early return for integers
-    if not isinstance(peer, TLObject):
-        if isinstance(peer, int):
-            return peer
-        else:
-            _raise_cast_fail(peer, 'int')
-
-    elif type(peer).SUBCLASS_OF_ID not in {0x2d45687, 0xc91c90b6}:
-        # Not a Peer or an InputPeer, so first get its Input version
-        peer = get_input_peer(peer, allow_self=False)
+    if isinstance(peer, int):
+        return peer
+
+    try:
+        if peer.SUBCLASS_OF_ID not in (0x2d45687, 0xc91c90b6):
+            # Not a Peer or an InputPeer, so first get its Input version
+            peer = get_input_peer(peer, allow_self=False)
+    except AttributeError:
+        _raise_cast_fail(peer, 'int')
 
     # Set the right ID/kind, or raise if the TLObject is not recognised
     if isinstance(peer, (PeerUser, InputPeerUser)):