Add a low bandwidth feed

lambda/sns_to_mqtt/__init__.py

@@ -23,6 +23,9 @@ logs = boto3.client('logs')
 sequenceToken = None
 log_stream_name = str(uuid.uuid4())
 
+MAX_CACHE = 10000 # how many serials should we cache
+cache = {}
+
 def handle_error(message, event, stream_name):
     global sequenceToken
     print(message)
@@ -125,6 +128,17 @@ def lambda_handler(event, context):
                     qos=0,
                     retain=False
                 )
+                if serial not in cache: # low bandwidth feeds with just the first packet
+                    client.publish(
+                        topic=f'{os.getenv("MQTT_PREFIX")}-new/{serial}',
+                        payload=body,
+                        qos=0,
+                        retain=False
+                    )
+                    cache[serial] = body
+                    # clean up cache if its too long
+                    while len(cache) > MAX_CACHE:
+                        del cache[next(iter(cache))]
             client.publish(
                 topic=os.getenv("MQTT_BATCH"),
                 payload=json.dumps(payloads),