From: Roger A. Light <roger@atchoo.org>
Date: Sat, 7 Jun 2014 20:00:05 +0000 (+0100)
Subject: Add support for "session present" in CONNACK and on_connect.
X-Git-Tag: v1.0~1^2~2
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=713955bd6123059044d928526d01d3aa4f8b16ca;p=packages%2Fp%2Fpaho-mqtt.git

Add support for "session present" in CONNACK and on_connect.

Change-Id: Icbcb603f4e5f42ff2fa35fb780ba5410248c1db0
---

diff --git a/README.rst b/README.rst
index ddc5149..e93611d 100644
--- a/README.rst
+++ b/README.rst
@@ -82,7 +82,7 @@ Here is a very simple example that subscribes to the broker $SYS topic tree and
     import paho.mqtt.client as mqtt
     
     # The callback for when the client receives a CONNACK response from the server.
-    def on_connect(client, userdata, rc):
+    def on_connect(client, userdata, flags, rc):
         print("Connected with result code "+str(rc))
 
         # Subscribing in on_connect() means that if we lose the connection and
@@ -566,7 +566,7 @@ on_connect()
 
 ::
 
-    on_connect(client, userdata, rc)
+    on_connect(client, userdata, flags, rc)
     
 Called when the broker responds to our connection request.
 
@@ -576,9 +576,19 @@ client
 userdata
     the private user data as set in ``Client()`` or ``userdata_set()``
 
+flags
+    response flags sent by the broker
 rc
     the connection result
 
+
+flags is a dict that contains response flags from the broker:
+    flags['session present'] - this flag is useful for clients that are
+        using clean session set to 0 only. If a client with clean
+        session=0, that reconnects to a broker that it has previously
+        connected to, this flag indicates whether the broker still has the
+        session information for the client. If 1, the session still exists.
+
 The value of rc indicates success or not: 
 
     0: Connection successful 
@@ -594,7 +604,7 @@ Example
 
 ::
 
-    def on_connect(client, userdata, rc):
+    def on_connect(client, userdata, flags, rc):
         print("Connection returned result: "+connack_string(rc))
         
     mqttc.on_connect = on_connect
diff --git a/examples/mqtt_clear_retain.py b/examples/mqtt_clear_retain.py
index dc88a4b..13f5754 100755
--- a/examples/mqtt_clear_retain.py
+++ b/examples/mqtt_clear_retain.py
@@ -31,7 +31,7 @@ except ImportError:
 
 final_mid = 0
 
-def on_connect(mqttc, userdata, rc):
+def on_connect(mqttc, userdata, flags, rc):
     if userdata == True:
         print("rc: "+str(rc))
 
diff --git a/examples/session_present.py b/examples/session_present.py
new file mode 100755
index 0000000..b5e2271
--- /dev/null
+++ b/examples/session_present.py
@@ -0,0 +1,68 @@
+#!/usr/bin/python
+
+# Copyright (c) 2014 Roger Light <roger@atchoo.org>
+#
+# All rights reserved. This program and the accompanying materials
+# are made available under the terms of the Eclipse Distribution License v1.0
+# which accompanies this distribution. 
+#
+# The Eclipse Distribution License is available at 
+#   http://www.eclipse.org/org/documents/edl-v10.php.
+#
+# Contributors:
+#    Roger Light - initial implementation
+# Copyright (c) 2014 Roger Light <roger@atchoo.org>
+# All rights reserved.
+
+# This demonstrates the session present flag when connecting.
+
+import sys
+try:
+    import paho.mqtt.client as mqtt
+except ImportError:
+    # This part is only required to run the example from within the examples
+    # directory when the module itself is not installed.
+    #
+    # If you have the module installed, just use "import paho.mqtt.client"
+    import os
+    import inspect
+    cmd_subfolder = os.path.realpath(os.path.abspath(os.path.join(os.path.split(inspect.getfile( inspect.currentframe() ))[0],"../src")))
+    if cmd_subfolder not in sys.path:
+        sys.path.insert(0, cmd_subfolder)
+    import paho.mqtt.client as mqtt
+
+def on_connect(mqttc, obj, flags, rc):
+    if obj == 0:
+        print("First connection:")
+    elif obj == 1:
+        print("Second connection:")
+    elif obj == 2:
+        print("Third connection (with clean session=True):")
+    print("    Session present: "+str(flags['session present']))
+    print("    Connection result: "+str(rc))
+    mqttc.disconnect()
+
+def on_disconnect(mqttc, obj, rc):
+    mqttc.user_data_set(obj+1)
+    if obj == 0:
+        mqttc.reconnect()
+
+def on_log(mqttc, obj, level, string):
+    print(string)
+
+mqttc = mqtt.Client(client_id="asdfj", clean_session=False)
+mqttc.on_connect = on_connect
+mqttc.on_disconnect = on_disconnect
+# Uncomment to enable debug messages
+#mqttc.on_log = on_log
+mqttc.user_data_set(0)
+mqttc.connect("test.mosquitto.org", 1883, 60)
+
+mqttc.loop_forever()
+
+# Clear session
+mqttc = mqtt.Client(client_id="asdfj", clean_session=True)
+mqttc.on_connect = on_connect
+mqttc.user_data_set(2)
+mqttc.connect("test.mosquitto.org", 1883, 60)
+mqttc.loop_forever()
diff --git a/examples/sub-class.py b/examples/sub-class.py
index 20e6fe4..1bc9b43 100755
--- a/examples/sub-class.py
+++ b/examples/sub-class.py
@@ -37,7 +37,7 @@ class MyMQTTClass:
         self._mqttc.on_publish = self.mqtt_on_publish
         self._mqttc.on_subscribe = self.mqtt_on_subscribe
 
-    def mqtt_on_connect(self, mqttc, obj, rc):
+    def mqtt_on_connect(self, mqttc, obj, flags, rc):
         print("rc: "+str(rc))
 
     def mqtt_on_message(self, mqttc, obj, msg):
diff --git a/examples/sub-srv.py b/examples/sub-srv.py
index b5103a0..aa731d1 100755
--- a/examples/sub-srv.py
+++ b/examples/sub-srv.py
@@ -31,7 +31,7 @@ except ImportError:
         sys.path.insert(0, cmd_subfolder)
     import paho.mqtt.client as mqtt
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     print "Connected to %s:%s" % (mqttc._host, mqttc._port)
 
 def on_message(mqttc, obj, msg):
diff --git a/examples/sub.py b/examples/sub.py
index 0b121eb..c7c233c 100755
--- a/examples/sub.py
+++ b/examples/sub.py
@@ -31,7 +31,7 @@ except ImportError:
         sys.path.insert(0, cmd_subfolder)
     import paho.mqtt.client as mqtt
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     print("rc: "+str(rc))
 
 def on_message(mqttc, obj, msg):
diff --git a/src/paho/mqtt/client.py b/src/paho/mqtt/client.py
index 1f75483..2f47861 100755
--- a/src/paho/mqtt/client.py
+++ b/src/paho/mqtt/client.py
@@ -318,7 +318,7 @@ class Client(object):
     broker. To use a callback, define a function and then assign it to the
     client:
 
-    def on_connect(client, userdata, rc):
+    def on_connect(client, userdata, flags, rc):
         print("Connection returned " + str(rc))
 
     client.on_connect = on_connect
@@ -330,15 +330,22 @@ class Client(object):
 
     The callbacks:
 
-    on_connect(client, userdata, rc): called when the broker responds to our connection
-      request. The value of rc determines success or not:
-      0: Connection successful
-      1: Connection refused - incorrect protocol version
-      2: Connection refused - invalid client identifier
-      3: Connection refused - server unavailable
-      4: Connection refused - bad username or password
-      5: Connection refused - not authorised
-      6-255: Currently unused.
+    on_connect(client, userdata, flags, rc): called when the broker responds to our connection
+      request.
+      flags is a dict that contains response flags from the broker:
+        flags['session present'] - this flag is useful for clients that are
+            using clean session set to 0 only. If a client with clean
+            session=0, that reconnects to a broker that it has previously
+            connected to, this flag indicates whether the broker still has the
+            session information for the client. If 1, the session still exists.
+      The value of rc determines success or not:
+        0: Connection successful
+        1: Connection refused - incorrect protocol version
+        2: Connection refused - invalid client identifier
+        3: Connection refused - server unavailable
+        4: Connection refused - bad username or password
+        5: Connection refused - not authorised
+        6-255: Currently unused.
 
     on_disconnect(client, userdata, rc): called when the client disconnects from the broker.
       The rc parameter indicates the disconnection state. If MQTT_ERR_SUCCESS
@@ -1904,22 +1911,35 @@ class Client(object):
         if len(self._in_packet['packet']) != 2:
             return MQTT_ERR_PROTOCOL
 
-        (resvd, result) = struct.unpack("!BB", self._in_packet['packet'])
+        (flags, result) = struct.unpack("!BB", self._in_packet['packet'])
         if result == CONNACK_REFUSED_PROTOCOL_VERSION and self._protocol == MQTTv311:
-            self._easy_log(MQTT_LOG_DEBUG, "Received CONNACK ("+str(resvd)+", "+str(result)+"), attempting downgrade to MQTT v3.1.")
+            self._easy_log(MQTT_LOG_DEBUG, "Received CONNACK ("+str(flags)+", "+str(result)+"), attempting downgrade to MQTT v3.1.")
             # Downgrade to MQTT v3.1
             self._protocol = MQTTv31
             return self.reconnect()
 
-        self._easy_log(MQTT_LOG_DEBUG, "Received CONNACK ("+str(resvd)+", "+str(result)+")")
+        if result == 0:
+            self._state = mqtt_cs_connected
+
+        self._easy_log(MQTT_LOG_DEBUG, "Received CONNACK ("+str(flags)+", "+str(result)+")")
         self._callback_mutex.acquire()
         if self.on_connect:
             self._in_callback = True
-            self.on_connect(self, self._userdata, result)
+
+            if sys.version_info[0] < 3:
+                argcount = self.on_connect.func_code.co_argcount
+            else:
+                argcount = self.on_connect.__code__.co_argcount
+
+            if argcount == 3:
+                self.on_connect(self, self._userdata, result)
+            else:
+                flags_dict = dict()
+                flags_dict['session present'] = flags & 0x01
+                self.on_connect(self, self._userdata, flags_dict, result)
             self._in_callback = False
         self._callback_mutex.release()
         if result == 0:
-            self._state = mqtt_cs_connected
             return MQTT_ERR_SUCCESS
         elif result > 0 and result < 6:
             return MQTT_ERR_CONN_REFUSED
diff --git a/src/paho/mqtt/publish.py b/src/paho/mqtt/publish.py
index 89aae28..6a0e045 100644
--- a/src/paho/mqtt/publish.py
+++ b/src/paho/mqtt/publish.py
@@ -49,7 +49,7 @@ def _do_publish(c):
     c.publish(topic, payload, qos, retain)
 
 
-def _on_connect(c, userdata, rc):
+def _on_connect(c, userdata, flags, rc):
     """Internal callback"""
     _do_publish(c)
 
diff --git a/test/lib/python/01-con-discon-success.test b/test/lib/python/01-con-discon-success.test
index 489fece..b150f9c 100755
--- a/test/lib/python/01-con-discon-success.test
+++ b/test/lib/python/01-con-discon-success.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/01-keepalive-pingreq.test b/test/lib/python/01-keepalive-pingreq.test
index 8dd7512..7a092b5 100755
--- a/test/lib/python/01-keepalive-pingreq.test
+++ b/test/lib/python/01-keepalive-pingreq.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
 
diff --git a/test/lib/python/02-subscribe-qos0.test b/test/lib/python/02-subscribe-qos0.test
index b964f62..001e0f8 100755
--- a/test/lib/python/02-subscribe-qos0.test
+++ b/test/lib/python/02-subscribe-qos0.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/02-subscribe-qos1.test b/test/lib/python/02-subscribe-qos1.test
index 6fc247f..3400dc5 100755
--- a/test/lib/python/02-subscribe-qos1.test
+++ b/test/lib/python/02-subscribe-qos1.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/02-subscribe-qos2.test b/test/lib/python/02-subscribe-qos2.test
index 9d52faa..2776317 100755
--- a/test/lib/python/02-subscribe-qos2.test
+++ b/test/lib/python/02-subscribe-qos2.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/02-unsubscribe.test b/test/lib/python/02-unsubscribe.test
index 4a52779..eab5e8a 100755
--- a/test/lib/python/02-unsubscribe.test
+++ b/test/lib/python/02-unsubscribe.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/03-publish-b2c-qos1.test b/test/lib/python/03-publish-b2c-qos1.test
index ef6d100..3b553df 100755
--- a/test/lib/python/03-publish-b2c-qos1.test
+++ b/test/lib/python/03-publish-b2c-qos1.test
@@ -27,7 +27,7 @@ def on_message(mqttc, obj, msg):
         exit(1)
     exit(0)
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         print("Connect failed ("+str(rc)+")")
         exit(rc)
diff --git a/test/lib/python/03-publish-b2c-qos2.test b/test/lib/python/03-publish-b2c-qos2.test
index 4540b55..da8da76 100755
--- a/test/lib/python/03-publish-b2c-qos2.test
+++ b/test/lib/python/03-publish-b2c-qos2.test
@@ -30,7 +30,7 @@ def on_message(mqttc, obj, msg):
 
     run = 0
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
 
diff --git a/test/lib/python/03-publish-c2b-qos1-disconnect.test b/test/lib/python/03-publish-c2b-qos1-disconnect.test
index 8fc4a1d..a409cb9 100755
--- a/test/lib/python/03-publish-c2b-qos1-disconnect.test
+++ b/test/lib/python/03-publish-c2b-qos1-disconnect.test
@@ -11,7 +11,7 @@ import paho.mqtt.client as mqtt
 
 sent_mid = -1
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     global sent_mid
     if rc != 0:
         exit(rc)
diff --git a/test/lib/python/03-publish-c2b-qos1-timeout.test b/test/lib/python/03-publish-c2b-qos1-timeout.test
index 26a24ca..b691267 100755
--- a/test/lib/python/03-publish-c2b-qos1-timeout.test
+++ b/test/lib/python/03-publish-c2b-qos1-timeout.test
@@ -11,7 +11,7 @@ import paho.mqtt.client as mqtt
 
 sent_mid = -1
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     global sent_mid
     if rc != 0:
         exit(rc)
diff --git a/test/lib/python/03-publish-c2b-qos2-disconnect.test b/test/lib/python/03-publish-c2b-qos2-disconnect.test
index d4c6f69..f3bf38b 100755
--- a/test/lib/python/03-publish-c2b-qos2-disconnect.test
+++ b/test/lib/python/03-publish-c2b-qos2-disconnect.test
@@ -11,7 +11,7 @@ import paho.mqtt.client as mqtt
 
 first_connection = 1
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     global first_connection
     if rc != 0:
         exit(rc)
diff --git a/test/lib/python/03-publish-c2b-qos2-timeout.test b/test/lib/python/03-publish-c2b-qos2-timeout.test
index 892204b..17f8b7c 100755
--- a/test/lib/python/03-publish-c2b-qos2-timeout.test
+++ b/test/lib/python/03-publish-c2b-qos2-timeout.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/03-publish-qos0-no-payload.test b/test/lib/python/03-publish-qos0-no-payload.test
index f247f40..fa44204 100755
--- a/test/lib/python/03-publish-qos0-no-payload.test
+++ b/test/lib/python/03-publish-qos0-no-payload.test
@@ -11,7 +11,7 @@ import paho.mqtt.client as mqtt
 
 sent_mid = -1
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     global sent_mid
     if rc != 0:
         exit(rc)
diff --git a/test/lib/python/03-publish-qos0.test b/test/lib/python/03-publish-qos0.test
index 0cbb7da..af4f892 100755
--- a/test/lib/python/03-publish-qos0.test
+++ b/test/lib/python/03-publish-qos0.test
@@ -11,7 +11,7 @@ import paho.mqtt.client as mqtt
 
 sent_mid = -1
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     global sent_mid
     if rc != 0:
         exit(rc)
diff --git a/test/lib/python/04-retain-qos0.test b/test/lib/python/04-retain-qos0.test
index 1564648..4a46249 100755
--- a/test/lib/python/04-retain-qos0.test
+++ b/test/lib/python/04-retain-qos0.test
@@ -10,7 +10,7 @@ from struct import *
 import paho.mqtt.client as mqtt
 
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/08-ssl-connect-cert-auth.test b/test/lib/python/08-ssl-connect-cert-auth.test
index a7b4835..8f2eba8 100755
--- a/test/lib/python/08-ssl-connect-cert-auth.test
+++ b/test/lib/python/08-ssl-connect-cert-auth.test
@@ -13,7 +13,7 @@ if sys.version < '2.7':
     print("WARNING: SSL/TLS not supported on Python 2.6")
     exit(0)
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/08-ssl-connect-no-auth.test b/test/lib/python/08-ssl-connect-no-auth.test
index 1f30937..ce48e03 100755
--- a/test/lib/python/08-ssl-connect-no-auth.test
+++ b/test/lib/python/08-ssl-connect-no-auth.test
@@ -13,7 +13,7 @@ if sys.version < '2.7':
     print("WARNING: SSL/TLS not supported on Python 2.6")
     exit(0)
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     if rc != 0:
         exit(rc)
     else:
diff --git a/test/lib/python/08-ssl-fake-cacert.test b/test/lib/python/08-ssl-fake-cacert.test
index f876a10..2afc198 100755
--- a/test/lib/python/08-ssl-fake-cacert.test
+++ b/test/lib/python/08-ssl-fake-cacert.test
@@ -14,7 +14,7 @@ if sys.version < '2.7':
     print("WARNING: SSL/TLS not supported on Python 2.6")
     exit(0)
 
-def on_connect(mqttc, obj, rc):
+def on_connect(mqttc, obj, flags, rc):
     exit(1)
 
 mqttc = mqtt.Client("08-ssl-fake-cacert")