Improve message_id generation speed.

bombela · bombela · commit 93c4e889634b · 2012-06-01T15:20:07.000-07:00
Messages ids are currently UUID4, and can't be yet replaced by a faster
and more efficient format because of some backward compatibilities
issues.

The solution here is to generate an UUID4 as a base, and then replace
its "time_low" part (4 bytes) by a randomly chosen unsigned integer
(32bits) incrementing until a randomly chosen limit.  When the limit is
reached, a new UUID4 is generated and a new value is randomly chosen for
the unsigned integer and its limit.

Speedup is between ~4x and ~20x depending of the speed of the local
entropy generation.
diff --git a/zerorpc/context.py b/zerorpc/context.py
@@ -25,6 +25,7 @@
 
 import uuid
 import functools
+import random
 
 import gevent_zmq as zmq
 
@@ -42,15 +43,25 @@ def __init__(self):
             'get_task_context': [],
             'inspect_error': []
         }
+        self._reset_msgid()
 
     @staticmethod
     def get_instance():
         if Context._instance is None:
             Context._instance = Context()
         return Context._instance
 
+    def _reset_msgid(self):
+        self._msg_id_base = str(uuid.uuid4())[8:]
+        self._msg_id_counter = random.randrange(0, 2**32)
+        self._msg_id_counter_stop = random.randrange(self._msg_id_counter, 2**32)
+
     def new_msgid(self):
-        return str(uuid.uuid4())
+        if (self._msg_id_counter >= self._msg_id_counter_stop):
+            self._reset_msgid()
+        else:
+            self._msg_id_counter = (self._msg_id_counter + 1) & 0xffffffff
+        return '{0:08x}{1}'.format(self._msg_id_counter, self._msg_id_base)
 
     def register_middleware(self, middleware_instance):
         registered_count = 0
