Make currently implemented jobs use @functools.total_ordering

This allows jobs to be fully be comparable using the total
ordering function to provide the complexity around the various
functions needed to achieve/perform comparisons.

Also fixes up the various job __eq__ and __lt__ methods to
correctly return 'NotImplemented' on unknown types and adds
a __hash__ to the redis job (so that it can be used in hashable
collections, just like the zookeeper job class).

Change-Id: I8820d5cc6b2e7f346ac329f011f41b76fa94b777

taskflow/jobs/backends/impl_redis.py

@@ -16,6 +16,7 @@
 
 import contextlib
 import datetime
+import functools
 import string
 import threading
 import time
@@ -59,6 +60,7 @@ def _translate_failures():
                              " internal error")
 
 
+@functools.total_ordering
 class RedisJob(base.Job):
     """A redis job."""
 
@@ -127,10 +129,24 @@ class RedisJob(base.Job):
                                    prior_version=self._redis_version)
 
     def __lt__(self, other):
-        if self.created_on == other.created_on:
-            return self.sequence < other.sequence
+        if not isinstance(other, RedisJob):
+            return NotImplemented
+        if self.board.listings_key == other.board.listings_key:
+            if self.created_on == other.created_on:
+                return self.sequence < other.sequence
+            else:
+                return self.created_on < other.created_on
         else:
-            return self.created_on < other.created_on
+            return self.board.listings_key < other.board.listings_key
+
+    def __eq__(self, other):
+        if not isinstance(other, RedisJob):
+            return NotImplemented
+        return ((self.board.listings_key, self.created_on, self.sequence) ==
+                (other.board.listings_key, other.created_on, other.sequence))
+
+    def __hash__(self):
+        return hash((self.board.listings_key, self.created_on, self.sequence))
 
     @property
     def created_on(self):

taskflow/jobs/backends/impl_zookeeper.py

@@ -41,6 +41,7 @@ from taskflow.utils import misc
 LOG = logging.getLogger(__name__)
 
 
+@functools.total_ordering
 class ZookeeperJob(base.Job):
     """A zookeeper job."""
 
@@ -171,11 +172,19 @@ class ZookeeperJob(base.Job):
         return states.CLAIMED
 
     def __lt__(self, other):
+        if not isinstance(other, ZookeeperJob):
+            return NotImplemented
         if self.root == other.root:
             return self.sequence < other.sequence
         else:
             return self.root < other.root
 
+    def __eq__(self, other):
+        if not isinstance(other, ZookeeperJob):
+            return NotImplemented
+        return ((self.root, self.sequence) ==
+                (other.root, other.sequence))
+
     def __hash__(self):
         return hash(self.path)