Merge pull request #25 from strayge/master

Add periodic pings (fixes #24)

telethon/network/mtproto_sender.py

@@ -1,13 +1,14 @@
 import gzip
 from datetime import timedelta
 from threading import RLock, Thread
-from time import sleep
+from time import sleep, time
 
 import telethon.helpers as utils
 from telethon.crypto import AES
 from telethon.errors import *
 from telethon.tl.all_tlobjects import tlobjects
 from telethon.tl.types import MsgsAck
+from telethon.tl.functions import PingRequest
 from telethon.utils import BinaryReader, BinaryWriter
 
 
@@ -30,7 +31,13 @@ class MtProtoSender:
 
         self.updates_thread = Thread(
             target=self.updates_thread_method, name='Updates thread')
-        self.updates_thread_running = False
+
+        # Signal for correct stopping update thread
+        self.updates_thread_stopping = False
+
+        self.ping_interval = 60
+        self.ping_time_last = time()
+
         self.updates_thread_receiving = False
 
         # Determine whether the received acknowledge request confirm
@@ -39,9 +46,15 @@ class MtProtoSender:
         # TODO There might be a better way to handle msgs_ack requests
         self.ack_requests_confirm = False
 
+        # Always running thread for periodical ping requests
+        # after all initialization is complete
+        self.updates_thread.start()
+
     def disconnect(self):
         """Disconnects and **stops all the running threads** if any"""
         self.set_listen_for_updates(enabled=False)
+        # Stop thread on next loop cycle
+        self.updates_thread_stopping = True
         self.transport.close()
 
     def add_update_handler(self, handler):
@@ -75,6 +88,12 @@ class MtProtoSender:
 
     # region Send and receive
 
+    def send_ping(self):
+        """Sends PingRequest"""
+        request = PingRequest(0)
+        self.send(request)
+        self.receive(request)
+
     def send(self, request):
         """Sends the specified MTProtoRequest, previously sending any message
            which needed confirmation. This also pauses the updates thread"""
@@ -340,13 +359,8 @@ class MtProtoSender:
 
     def set_listen_for_updates(self, enabled):
         if enabled:
-            if not self.updates_thread_running:
+            self.updates_thread_receiving = False
-                self.updates_thread_running = True
-                self.updates_thread_receiving = False
-
-                self.updates_thread.start()
         else:
-            self.updates_thread_running = False
             if self.updates_thread_receiving:
                 self.transport.cancel_receive()
 
@@ -356,11 +370,20 @@ class MtProtoSender:
         # Set a reasonable timeout when checking for updates
         timeout = timedelta(minutes=1)
 
-        while self.updates_thread_running:
+        while not self.updates_thread_stopping:
             # Only try to receive updates if we're not waiting to receive a request
             if not self.waiting_receive:
                 with self.lock:
                     try:
+                        now = time()
+                        # if ping_interval seconds passed since last ping
+                        # (or startup) - send new one
+                        if now >= self.ping_time_last + self.ping_interval:
+                            self.ping_time_last = now
+                            self.send_ping()
+                            # if sending ping - we doesn't processing any other updates
+                            continue
+
                         self.updates_thread_receiving = True
                         seq, body = self.transport.receive(timeout)
                         message, remote_msg_id, remote_sequence = self.decode_msg(
@@ -378,5 +401,5 @@ class MtProtoSender:
             # If we are here, it is because the read was cancelled
             # Sleep a bit just to give enough time for the other thread
             # to acquire the lock. No need to sleep if we're not running anymore
-            if self.updates_thread_running:
+            if not self.updates_thread_stopping:
                 sleep(0.1)

telethon_tests/network_test.py

@@ -32,7 +32,7 @@ class NetworkTests(unittest.TestCase):
         client.connect('localhost', port)
         client.write(msg)
         assert msg == client.read(
-            16), 'Read message does not equal sent message'
+            15), 'Read message does not equal sent message'
         client.close()
 
     @staticmethod