Flesh out gateway client

README.md

@@ -3,7 +3,6 @@ A Discord Python bot built to be easy to use and scale.
 
 ## TODOS
 
-- flesh out gateway paths (reconnect/resume)
 - flesh out API client
 - storage/database/config
 - flesh out type methods

disco/client.py

@@ -23,7 +23,7 @@ class DiscoClient(object):
         self.gw = GatewayClient(self)
 
     def run(self):
-        return self.gw.run()
+        return gevent.spawn(self.gw.run)
 
     def run_forever(self):
-        return self.gw.run().join()
+        return self.gw.run()

disco/gateway/client.py

@@ -2,6 +2,7 @@ import websocket
 import gevent
 import json
 import zlib
+import six
 
 from disco.gateway.packets import OPCode, HeartbeatPacket, ResumePacket, IdentifyPacket
 from disco.gateway.events import GatewayEvent
@@ -11,17 +12,18 @@ GATEWAY_VERSION = 6
 TEN_MEGABYTES = 10490000
 
 
-def log_error(log, msg, w):
-    def _f(*args, **kwargs):
-        try:
-            return w(*args, **kwargs)
-        except:
-            log.exception(msg)
-            raise
-    return _f
+# Hack to get websocket close information
+def websocket_get_close_args_override(data):
+    if data and len(data) >= 2:
+        code = 256 * six.byte2int(data[0:1]) + six.byte2int(data[1:2])
+        reason = data[2:].decode('utf-8')
+        return [code, reason]
+    return [None, None]
 
 
 class GatewayClient(LoggingClass):
+    MAX_RECONNECTS = 5
+
     def __init__(self, client):
         super(GatewayClient, self).__init__()
         self.client = client
@@ -42,8 +44,6 @@ class GatewayClient(LoggingClass):
         # Heartbeat
         self._heartbeat_task = None
 
-        self._fatal_error_promise = gevent.event.AsyncResult()
-
     def send(self, packet):
         self.ws.send(json.dumps({
             'op': int(packet.OP),
@@ -61,13 +61,17 @@ class GatewayClient(LoggingClass):
         self.client.events.emit(obj.__class__.__name__, obj)
 
     def handle_heartbeat(self, packet):
-        pass
+        self.send(HeartbeatPacket(data=self.seq))
 
     def handle_reconnect(self, packet):
-        pass
+        self.log.warning('Received RECONNECT request, forcing a fresh reconnect')
+        self.session_id = None
+        self.ws.close()
 
     def handle_invalid_session(self, packet):
-        pass
+        self.log.warning('Recieved INVALID_SESSIOIN, forcing a fresh reconnect')
+        self.sesion_id = None
+        self.ws.close()
 
     def handle_hello(self, packet):
         self.log.info('Recieved HELLO, starting heartbeater...')
@@ -88,11 +92,12 @@ class GatewayClient(LoggingClass):
         self.log.info('Opening websocket connection to URL `%s`', self._cached_gateway_url)
         self.ws = websocket.WebSocketApp(
             self._cached_gateway_url,
-            on_message=log_error(self.log, 'Error in on_message:', self.on_message),
-            on_error=log_error(self.log, 'Error in on_error:', self.on_error),
-            on_open=log_error(self.log, 'Error in on_open:', self.on_open),
-            on_close=log_error(self.log, 'Error in on_close:', self.on_close),
+            on_message=self.log_on_error('Error in on_message:', self.on_message),
+            on_error=self.log_on_error('Error in on_error:', self.on_error),
+            on_open=self.log_on_error('Error in on_open:', self.on_open),
+            on_close=self.log_on_error('Error in on_close:', self.on_close),
         )
+        self.ws._get_close_args = websocket_get_close_args_override
 
     def on_message(self, ws, msg):
         # Detect zlib and decompress
@@ -125,27 +130,41 @@ class GatewayClient(LoggingClass):
             raise Exception('Unknown packet: {}'.format(data['op']))
 
     def on_error(self, ws, error):
-        print 'error', error
+        raise Exception('WS recieved error: %s', error)
 
     def on_open(self, ws):
-        print 'on open'
         if self.seq and self.session_id:
+            self.log.info('WS Opened: attempting resume w/ SID: %s SEQ: %s', self.session_id, self.seq)
             self.send(ResumePacket(seq=self.seq, session_id=self.session_id, token=self.client.token))
         else:
+            self.log.info('WS Opened: sending identify payload')
             self.send(IdentifyPacket(
                 token=self.client.token,
                 compress=True,
                 large_threshold=250,
                 shard=[self.client.sharding['number'], self.client.sharding['total']]))
 
-    def on_close(self, ws):
-        print 'close'
+    def on_close(self, ws, code, reason):
+        self.reconnects += 1
+        self.log.info('WS Closed: [%s] %s (%s)', code, reason, self.reconnects)
 
-    def run(self):
-        self.connect()
+        if self.MAX_RECONNECTS and self.reconnects > self.MAX_RECONNECTS:
+            raise Exception('Failed to reconect after {} attempts, giving up'.format(self.MAX_RECONNECTS))
+
+        # Don't resume for these error codes
+        if 4000 <= code <= 4010:
+            self.session_id = None
+            self.log.info('Attempting fresh reconnect')
+        else:
+            self.log.info('Attempting resume')
 
-        # Spawn a thread to run the connection loop forever
-        gevent.spawn(self.ws.run_forever)
+        wait_time = self.reconnects * 5
+        self.log.info('Will attempt to {} after {} seconds', 'resume' if self.session_id else 'reconnect', wait_time)
+        gevent.sleep(wait_time)
 
-        # Wait for a fatal error
-        self._fatal_error_promise.get()
+        # Reconnect
+        self.connect()
+
+    def run(self):
+        self.connect()
+        self.ws.run_forever()

disco/util/logging.py

@@ -6,3 +6,12 @@ import logging
 class LoggingClass(object):
     def __init__(self):
         self.log = logging.getLogger(self.__class__.__name__)
+
+    def log_on_error(self, msg, f):
+        def _f(*args, **kwargs):
+            try:
+                return f(*args, **kwargs)
+            except:
+                self.log.exception(msg)
+                raise
+        return _f