Implemented timestamp mark on messages to trigger message expiration logic in case something stays on the bus for longer than a minute

platypush/__init__.py

@@ -12,7 +12,6 @@ import traceback
 
 from threading import Thread
 
-from .bus import Bus
 from .bus.redis import RedisBus
 from .config import Config
 from .context import register_backends

platypush/bus/__init__.py

@@ -1,5 +1,6 @@
 import logging
 import threading
+import time
 
 from queue import Queue
 
@@ -12,6 +13,9 @@ logger = logging.getLogger(__name__)
 class Bus(object):
     """ Main local bus where the daemon will listen for new messages """
 
+    _MSG_EXPIRY_TIMEOUT = 60.0  # Consider a message on the bus as expired
+                                # after one minute without being picked up
+
     def __init__(self, on_message=None):
         self.bus = Queue()
         self.on_message = on_message
@@ -45,6 +49,11 @@ class Bus(object):
         stop=False
         while not stop:
             msg = self.get()
+            if msg.timestamp and time.time() - msg.timestamp > self._MSG_EXPIRY_TIMEOUT:
+                logger.info('{} seconds old message on the bus expired, ignoring it: {}'
+                            .format(int(time.time()-msg.timestamp), msg))
+                continue
+
             self.on_message(msg)
 
             if isinstance(msg, StopEvent) and msg.targets_me():

platypush/message/__init__.py

@@ -1,6 +1,7 @@
 import logging
 import inspect
 import json
+import time
 
 logger = logging.getLogger(__name__)
 
@@ -17,7 +18,7 @@ class Message(object):
         return json.dumps({
             attr: getattr(self, attr)
             for attr in self.__dir__()
-            if not attr.startswith('_')
+            if (attr != '_timestamp' or not attr.startswith('_'))
             and not inspect.ismethod(getattr(self, attr))
         }).replace('\n', ' ')
 
@@ -48,6 +49,10 @@ class Message(object):
                 logger.warning('Invalid JSON message: {}'.format(msg))
 
         assert isinstance(msg, dict)
+
+        if not '_timestamp' in msg:
+            msg['_timestamp'] = time.time()
+
         return msg
 
     @classmethod

platypush/message/event/__init__.py

@@ -3,6 +3,7 @@ import json
 import random
 import re
 import threading
+import time
 
 from datetime import date
 
@@ -13,7 +14,7 @@ from platypush.utils import get_event_class_by_type
 class Event(Message):
     """ Event message class """
 
-    def __init__(self, target=None, origin=None, id=None, **kwargs):
+    def __init__(self, target=None, origin=None, id=None, timestamp=None, **kwargs):
         """
         Params:
             target  -- Target node [String]
@@ -28,6 +29,7 @@ class Event(Message):
         self.type = '{}.{}'.format(self.__class__.__module__,
                                    self.__class__.__name__)
         self.args = kwargs
+        self.timestamp = timestamp or time.time()
 
     @classmethod
     def build(cls, msg):
@@ -42,6 +44,7 @@ class Event(Message):
         args['id'] = msg['id'] if 'id' in msg else cls._generate_id()
         args['target'] = msg['target'] if 'target' in msg else Config.get('device_id')
         args['origin'] = msg['origin'] if 'origin' in msg else Config.get('device_id')
+        args['timestamp'] = msg['_timestamp'] if '_timestamp' in msg else time.time()
         return event_class(**args)
 
 
@@ -168,6 +171,7 @@ class Event(Message):
             'target'   : self.target,
             'origin'   : self.origin if hasattr(self, 'origin') else None,
             'id'       : self.id if hasattr(self, 'id') else None,
+            '_timestamp' : self.timestamp,
             'args'     : {
                 'type' : self.type,
                 **args

platypush/message/request/__init__.py

@@ -4,6 +4,7 @@ import json
 import logging
 import random
 import re
+import time
 import traceback
 
 from threading import Thread
@@ -21,16 +22,17 @@ class Request(Message):
     """ Request message class """
 
     def __init__(self, target, action, origin=None, id=None, backend=None,
-                 args=None, token=None):
+                 args=None, token=None, timestamp=None):
         """
         Params:
-            target -- Target node [String]
+            target -- Target node [Str]
-            action -- Action to be executed (e.g. music.mpd.play) [String]
+            action -- Action to be executed (e.g. music.mpd.play) [Str]
-            origin -- Origin node [String]
+            origin -- Origin node [Str]
                 id -- Message ID, or None to get it auto-generated
            backend -- Backend connected to the request, where the response will be delivered
               args -- Additional arguments for the action [Dict]
              token -- Authorization token, if required on the server [Str]
+         timestamp -- Message creation timestamp [Float]
         """
 
         self.id      = id if id else self._generate_id()
@@ -40,6 +42,7 @@ class Request(Message):
         self.args    = args if args else {}
         self.backend = backend
         self.token   = token
+        self.timestamp = timestamp or time.time()
 
     @classmethod
     def build(cls, msg):
@@ -51,6 +54,7 @@ class Request(Message):
         }
 
         args['id'] = msg['id'] if 'id' in msg else cls._generate_id()
+        args['timestamp'] = msg['_timestamp'] if '_timestamp' in msg else time.time()
         if 'origin' in msg: args['origin'] = msg['origin']
         if 'token' in msg: args['token'] = msg['token']
         return cls(**args)
@@ -240,6 +244,7 @@ class Request(Message):
             'origin' : self.origin if hasattr(self, 'origin') else None,
             'id'     : self.id if hasattr(self, 'id') else None,
             'token'  : self.token if hasattr(self, 'token') else None,
+            '_timestamp' : self.timestamp,
         })
 
 

platypush/message/response/__init__.py

@@ -1,11 +1,13 @@
 import json
+import time
 
 from platypush.message import Message
 
 class Response(Message):
     """ Response message class """
 
-    def __init__(self, target=None, origin=None, id=None, output=None, errors=[]):
+    def __init__(self, target=None, origin=None, id=None, output=None, errors=[],
+                 timestamp=None):
         """
         Params:
             target -- Target [String]
@@ -13,12 +15,14 @@ class Response(Message):
             output -- Output [String]
             errors -- Errors [List of strings or exceptions]
                 id -- Message ID this response refers to
+         timestamp -- Message timestamp [Float]
         """
 
         self.target = target
         self.output = self._parse_msg(output)
         self.errors = self._parse_msg(errors)
         self.origin = origin
+        self.timestamp = timestamp or time.time()
         self.id = id
 
     def is_error(self):
@@ -45,6 +49,7 @@ class Response(Message):
             'errors' : msg['response']['errors'],
         }
 
+        args['timestamp'] = msg['_timestamp'] if '_timestamp' in msg else time.time()
         if 'id' in msg: args['id'] = msg['id']
         if 'origin' in msg: args['origin'] = msg['origin']
         return cls(**args)
@@ -61,6 +66,7 @@ class Response(Message):
             'type'       : 'response',
             'target'     : self.target if hasattr(self, 'target') else None,
             'origin'     : self.origin if hasattr(self, 'origin') else None,
+            '_timestamp' : self.timestamp,
             'response'   : {
                 'output' : self.output,
                 'errors' : self.errors,