Add option to discard retransmissions and option to disable debug mes…

…sages

README.md

@@ -222,6 +222,28 @@ customSocket = CustomSocket()
 client.setCustomSocket(customSocket)
 ```
 
+# Beta features under implementation or evaluation
+
+## Discard incomming retransmission
+
+If a received message is the same as the previously message received, it can be discarded. In that case, the poll function will not return at the time of retrieval and will continue to listen for futher incomming messages. Finally the defined responseCallback will not be called. 
+
+By default this simplistic feature is disabled. To enable:
+
+```python
+client = microcoapy.Coap()
+client.discardRetransmissions = True
+```
+
+## Activate / Deactivate debug messages
+
+By default, debug prints in microcoapy are enabled. Though, the user can deactivate the prints per Coap instance:
+
+```python
+client = microcoapy.Coap()
+client.debug = False
+```
+
 # Future work
 
 * Since this library is quite fresh, the next period will be full of testing.

microcoapy/microcoapy.py

@@ -12,27 +12,28 @@
 
 import binascii
 
-MICROCOAPY_DEBUG = True
-
-def log(s):
-    if MICROCOAPY_DEBUG:
-        print(s)
-
 class Coap:
     TRANSMISSION_STATE = macros.enum(
         STATE_IDLE = 0,
         STATE_SEPARATE_ACK_RECEIVED_WAITING_DATA = 1
     )
 
     def __init__(self):
-        self.debug = False
+        self.debug = True
         self.sock = None
         self.callbacks = {}
         self.resposeCallback = None
         self.port = 0
         self.isServer = False
         self.state = self.TRANSMISSION_STATE.STATE_IDLE
 
+        #beta flags
+        self.discardRetransmissions = False
+        self.lastPacketStr = ""
+
+    def log(self, s):
+        if self.debug:
+            print("[microcoapy]: " + s)
 
     # Create and initialize a new UDP socket to listen to.
     # port: the local port to be used.
@@ -88,7 +89,7 @@ def sendPacket(self, ip, port, coapPacket):
             if status > 0:
                 status = coapPacket.messageid
 
-            log('Packet sent. messageid: ' + str(status))
+            self.log('Packet sent. messageid: ' + str(status))
         except Exception as e:
             status = 0
             print('Exception while sending packet...')
@@ -208,7 +209,7 @@ def loop(self, blocking=True):
 
             packet = CoapPacket()
 
-            log("Packet bytes: " + str(binascii.hexlify(bytearray(buffer))))
+            self.log("Incoming Packet bytes: " + str(binascii.hexlify(bytearray(buffer))))
 
             parsePacketHeaderInfo(buffer, packet)
 
@@ -218,6 +219,15 @@ def loop(self, blocking=True):
             if not parsePacketOptionsAndPayload(buffer, packet):
                 return False
 
+            # beta functionality
+            if self.discardRetransmissions:
+                if packet.toString() == self.lastPacketStr:
+                    self.log("Discarded retransmission message: " + packet.toString())
+                    return False
+                else:
+                    self.lastPacketStr = packet.toString()
+            ####
+
             if self.isServer:
                 self.handleIncomingRequest(packet, remoteAddress[0], remoteAddress[1])
             else: