Added an updates thread and construtor_id to TLObjects

A new thread is now created when MtProtoSender is created.
This thread constantly listens for Telegram updates (such as
incoming messages), so the updates can be received any time
rather than only when sending another request.

errors.py

@@ -1,6 +1,12 @@
 import re
 
 
+class ReadCancelledError(Exception):
+    """Occurs when a read operation was cancelled"""
+    def __init__(self):
+        super().__init__(self, 'You must run `python3 tl_generator.py` first. #ReadTheDocs!')
+
+
 class TLGeneratorNotRan(Exception):
     """Occurs when you should've ran `tl_generator.py`, but you haven't"""
     def __init__(self):

main.py

@@ -78,4 +78,5 @@ if __name__ == '__main__':
             else:
                 client.send_message(input_peer, msg, markdown=True, no_web_page=True)
 
-    print('Thanks for trying the interactive example! Exiting.')
+    print('Thanks for trying the interactive example! Exiting...')
+    client.disconnect()

network/mtproto_sender.py

@@ -3,6 +3,7 @@
 import gzip
 from errors import *
 from time import sleep
+from threading import Thread
 
 import utils
 from crypto import AES
@@ -20,13 +21,27 @@ class MtProtoSender:
         self.need_confirmation = []  # Message IDs that need confirmation
         self.on_update_handlers = []
 
+        # Set up updates thread
+        self.updates_thread = Thread(target=self.updates_thread_method, name='Updates thread')
+        self.updates_thread_running = True
+        self.updates_thread_paused = True
+
+        self.updates_thread.start()
+
+    def disconnect(self):
+        """Disconnects and **stops all the running threads**"""
+        self.updates_thread_running = False
+        self.transport.cancel_receive()
+        self.transport.close()
+
     def add_update_handler(self, handler):
-        """Adds an update handler (a method with one argument, the received TLObject)
-        that is fired when there are updates available"""
+        """Adds an update handler (a method with one argument, the received
+           TLObject) that is fired when there are updates available"""
         self.on_update_handlers.append(handler)
 
     def generate_sequence(self, confirmed):
-        """Generates the next sequence number, based on whether it was confirmed yet or not"""
+        """Generates the next sequence number, based on whether it
+           was confirmed yet or not"""
         if confirmed:
             result = self.session.sequence * 2 + 1
             self.session.sequence += 1
@@ -37,26 +52,33 @@ class MtProtoSender:
     # region Send and receive
 
     def send(self, request):
-        """Sends the specified MTProtoRequest, previously sending any message which needed confirmation"""
+        """Sends the specified MTProtoRequest, previously sending any message
+           which needed confirmation. This also pauses the updates thread"""
 
-        # First check if any message needs confirmation, if this is the case, send an "AckRequest"
+        # Pause the updates thread: we cannot use self.transport at the same time!
+        self.pause_updates_thread()
+
+        # If any message needs confirmation send an AckRequest first
         if self.need_confirmation:
-            msgs_ack = MsgsAck(self.need_confirmation)
-            with BinaryWriter() as writer:
-                msgs_ack.on_send(writer)
-                self.send_packet(writer.get_bytes(), msgs_ack)
+            msgs_ack = MsgsAck(self.need_confirmation[:])
             del self.need_confirmation[:]
+            self.send(msgs_ack)
 
-        # Then send our packed request
+        # Finally send our packed request
         with BinaryWriter() as writer:
             request.on_send(writer)
             self.send_packet(writer.get_bytes(), request)
 
         # And update the saved session
         self.session.save()
+        # Don't resume the updates thread yet,
+        # since every send() is preceded by a receive()
 
     def receive(self, request):
-        """Receives the specified MTProtoRequest ("fills in it" the received data)"""
+        """Receives the specified MTProtoRequest ("fills in it"
+           the received data). This also restores the updates thread"""
+
+        # Don't stop receiving until we get the request we wanted
         while not request.confirm_received:
             seq, body = self.transport.receive()
             message, remote_msg_id, remote_sequence = self.decode_msg(body)
@@ -64,6 +86,9 @@ class MtProtoSender:
             with BinaryReader(message) as reader:
                 self.process_msg(remote_msg_id, remote_sequence, reader, request)
 
+        # Once we have our request, restore the updates thread
+        self.restore_updates_thread()
+
     # endregion
 
     # region Low level processing
@@ -120,26 +145,29 @@ class MtProtoSender:
 
         return message, remote_msg_id, remote_sequence
 
-    def process_msg(self, msg_id, sequence, reader, request):
-        """Processes and handles a Telegram message"""
+    def process_msg(self, msg_id, sequence, reader, request, only_updates=False):
+        """Processes and handles a Telegram message. Optionally, this
+           function will only check for updates (hence the request can be None)"""
+
         # TODO Check salt, session_id and sequence_number
         self.need_confirmation.append(msg_id)
 
         code = reader.read_int(signed=False)
         reader.seek(-4)
 
-        # The following codes are "parsed manually"
+        # The following codes are "parsed manually" (and do not refer to an update)
+        if not only_updates:
             if code == 0xf35c6d01:  # rpc_result
                 return self.handle_rpc_result(msg_id, sequence, reader, request)
-        elif code == 0x73f1f8dc:  # msg_container
+            if code == 0x73f1f8dc:  # msg_container
                 return self.handle_container(msg_id, sequence, reader, request)
-        elif code == 0x3072cfa1:  # gzip_packed
+            if code == 0x3072cfa1:  # gzip_packed
                 return self.handle_gzip_packed(msg_id, sequence, reader, request)
-        elif code == 0xedab447b:  # bad_server_salt
+            if code == 0xedab447b:  # bad_server_salt
                 return self.handle_bad_server_salt(msg_id, sequence, reader, request)
-        elif code == 0xa7eff811:  # bad_msg_notification
+            if code == 0xa7eff811:  # bad_msg_notification
                 return self.handle_bad_msg_notification(msg_id, sequence, reader)
-        else:
+
         # If the code is not parsed manually, then it was parsed by the code generator!
         # In this case, we will simply treat the incoming TLObject as an Update,
         # if we can first find a matching TLObject
@@ -196,18 +224,22 @@ class MtProtoSender:
         error_code = reader.read_int()
         raise BadMessageError(error_code)
 
-    def handle_rpc_result(self, msg_id, sequence, reader, mtproto_request):
+    def handle_rpc_result(self, msg_id, sequence, reader, request):
         code = reader.read_int(signed=False)
         request_id = reader.read_long(signed=False)
         inner_code = reader.read_int(signed=False)
 
-        if request_id == mtproto_request.msg_id:
-            mtproto_request.confirm_received = True
+        if not request:
+            raise ValueError('Cannot handle RPC results if no request was specified. '
+                             'This should only happen when the updates thread does not work properly.')
+
+        if request_id == request.msg_id:
+            request.confirm_received = True
 
         if inner_code == 0x2144ca19:  # RPC Error
             error = RPCError(code=reader.read_int(), message=reader.tgread_string())
             if error.must_resend:
-                mtproto_request.confirm_received = False
+                request.confirm_received = False
 
             if error.message.startswith('FLOOD_WAIT_'):
                 print('Should wait {}s. Sleeping until then.'.format(error.additional_data))
@@ -223,11 +255,11 @@ class MtProtoSender:
             if inner_code == 0x3072cfa1:  # GZip packed
                 unpacked_data = gzip.decompress(reader.tgread_bytes())
                 with BinaryReader(unpacked_data) as compressed_reader:
-                    mtproto_request.on_response(compressed_reader)
+                    request.on_response(compressed_reader)
 
             else:
                 reader.seek(-4)
-                mtproto_request.on_response(reader)
+                request.on_response(reader)
 
     def handle_gzip_packed(self, msg_id, sequence, reader, mtproto_request):
         code = reader.read_int(signed=False)
@@ -238,4 +270,30 @@ class MtProtoSender:
             self.process_msg(msg_id, sequence, compressed_reader, mtproto_request)
 
     # endregion
+
+    def pause_updates_thread(self):
+        """Pauses the updates thread and sleeps until it's safe to continue"""
+        if not self.updates_thread_paused:
+            self.updates_thread_paused = True
+            self.transport.cancel_receive()
+
+    def restore_updates_thread(self):
+        """Restores the updates thread"""
+        self.updates_thread_paused = False
+
+    # TODO avoid, if possible using sleeps; Use thread locks instead
+    def updates_thread_method(self):
+        """This method will run until specified and listen for incoming updates"""
+        while self.updates_thread_running:
+            if not self.updates_thread_paused:
+                try:
+                    seq, body = self.transport.receive()
+                    message, remote_msg_id, remote_sequence = self.decode_msg(body)
+
+                    with BinaryReader(message) as reader:
+                        self.process_msg(remote_msg_id, remote_sequence, reader, request=None, only_updates=True)
+
+                except ReadCancelledError:
                     pass
+
+            sleep(self.transport.get_client_delay())

network/tcp_client.py

@@ -1,5 +1,8 @@
 # Python rough implementation of a C# TCP client
 import socket
+import time
+
+from errors import ReadCancelledError
 from utils import BinaryWriter
 
 
@@ -7,16 +10,20 @@ class TcpClient:
     def __init__(self):
         self.connected = False
         self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.cancelled = False  # Has the read operation been cancelled?
+        self.delay = 0.1  # Read delay when there was no data available
 
     def connect(self, ip, port):
         """Connects to the specified IP and port number"""
         self.socket.connect((ip, port))
         self.connected = True
+        self.socket.setblocking(False)
 
     def close(self):
         """Closes the connection"""
         self.socket.close()
         self.connected = False
+        self.socket.setblocking(True)
 
     def write(self, data):
         """Writes (sends) the specified bytes to the connected peer"""
@@ -24,12 +31,36 @@ class TcpClient:
 
     def read(self, buffer_size):
         """Reads (receives) the specified bytes from the connected peer"""
+        self.cancelled = False  # Ensure it is not cancelled at first
+
         with BinaryWriter() as writer:
-            while writer.written_count < buffer_size:
+            while writer.written_count < buffer_size and not self.cancelled:
+                try:
                     # When receiving from the socket, we may not receive all the data at once
                     # This is why we need to keep checking to make sure that we receive it all
                     left_count = buffer_size - writer.written_count
                     partial = self.socket.recv(left_count)
                     writer.write(partial)
 
+                except BlockingIOError:
+                    # There was no data available for us to read. Sleep a bit
+                    time.sleep(self.delay)
+
+            # If the operation was cancelled *but* data was read,
+            # this will result on data loss so raise an exception
+            # TODO this could be solved by using an internal FIFO buffer (first in, first out)
+            if self.cancelled:
+                if writer.written_count == 0:
+                    raise ReadCancelledError()
+                else:
+                    raise NotImplementedError('The read operation was cancelled when some data '
+                                              'was already read. This has not yet implemented '
+                                              'an internal buffer, so cannot continue.')
+
             return writer.get_bytes()
+
+    def cancel_read(self):
+        """Cancels the read operation if it was blocking and stops
+           the current thread until it's cancelled"""
+        self.cancelled = True
+        time.sleep(self.delay)

network/tcp_transport.py

@@ -58,3 +58,12 @@ class TcpTransport:
     def close(self):
         if self.tcp_client.connected:
             self.tcp_client.close()
+
+    def cancel_receive(self):
+        """Cancels (stops) trying to receive from the remote peer and
+           stops the current thread until it's cancelled"""
+        self.tcp_client.cancel_read()
+
+    def get_client_delay(self):
+        """Gets the client read delay"""
+        return self.tcp_client.delay

tl/__init__.py

@@ -1,9 +1,4 @@
-try:
 from .all_tlobjects import tlobjects
 from .session import Session
 from .mtproto_request import MTProtoRequest
 from .telegram_client import TelegramClient
-
-except ImportError:
-    import errors
-    raise errors.TLGeneratorNotRan()

tl/mtproto_request.py

@@ -15,6 +15,7 @@ class MTProtoRequest:
         self.confirm_received = False
 
         # These should be overrode
+        self.constructor_id = 0
         self.confirmed = False
         self.responded = False
 

tl/telegram_client.py

@@ -9,6 +9,7 @@ from errors import *
 from network import MtProtoSender, TcpTransport
 from parser.markdown_parser import parse_message_entities
 
+# For sending and receiving requests
 from tl import Session
 from tl.types import PeerUser, PeerChat, PeerChannel, InputPeerUser, InputPeerChat, InputPeerChannel, InputPeerEmpty
 from tl.functions import InvokeWithLayerRequest, InitConnectionRequest
@@ -16,6 +17,9 @@ from tl.functions.help import GetConfigRequest
 from tl.functions.auth import SendCodeRequest, SignInRequest
 from tl.functions.messages import GetDialogsRequest, GetHistoryRequest, SendMessageRequest
 
+# For working with updates
+from tl.types import UpdateShortMessage
+
 
 class TelegramClient:
 
@@ -90,6 +94,11 @@ class TelegramClient:
 
         self.connect(reconnect=True)
 
+    def disconnect(self):
+        """Disconnects from the Telegram server **and pauses all the spawned threads**"""
+        if self.sender:
+            self.sender.disconnect()
+
     # endregion
 
     # region Telegram requests functions
@@ -261,6 +270,10 @@ class TelegramClient:
     def on_update(self, tlobject):
         """This method is fired when there are updates from Telegram.
         Add your own implementation below, or simply override it!"""
-        print('We have an update: {}'.format(str(tlobject)))
+
+        # Only show incoming messages
+        if type(tlobject) is UpdateShortMessage:
+            if not tlobject.out:
+                print('> User with ID {} said "{}"'.format(tlobject.user_id, tlobject.message))
 
     # endregion

tl_generator.py

@@ -54,6 +54,7 @@ def generate_tlobjects(scheme_file):
         with open(filename, 'w', encoding='utf-8') as file:
             # Let's build the source code!
             with SourceBuilder(file) as builder:
+                # Both types and functions inherit from MTProtoRequest so they all can be sent
                 builder.writeln('from tl.mtproto_request import MTProtoRequest')
                 builder.writeln()
                 builder.writeln()
@@ -105,6 +106,9 @@ def generate_tlobjects(scheme_file):
                     builder.writeln('self.result = None')
                     builder.writeln('self.confirmed = True  # Confirmed by default')
 
+                # Create an attribute that stores the TLObject's constructor ID
+                builder.writeln('self.constructor_id = {}'.format(hex(tlobject.id)))
+
                 # Set the arguments
                 if args:
                     # Leave an empty line if there are any args
@@ -115,7 +119,7 @@ def generate_tlobjects(scheme_file):
 
                 # Write the on_send(self, writer) function
                 builder.writeln('def on_send(self, writer):')
-                builder.writeln("writer.write_int({}, signed=False)  # {}'s constructor ID"
+                builder.writeln('writer.write_int(self.constructor_id, signed=False)'
                                 .format(hex(tlobject.id), tlobject.name))
 
                 for arg in tlobject.args: