From fa34b05c6c81063e7bb8fc6486a0c51e0969ae56 Mon Sep 17 00:00:00 2001
From: Fabio Manganiello <blacklight86@gmail.com>
Date: Thu, 4 Jan 2018 19:19:56 +0100
Subject: [PATCH] Priority-based algorithm for hooks, solves #41
---
platypush/event/hook.py | 12 +++++++++---
platypush/event/processor/__init__.py | 14 ++++++++++----
2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/platypush/event/hook.py b/platypush/event/hook.py
index fb81e785e..788acf617 100644
--- a/platypush/event/hook.py
+++ b/platypush/event/hook.py
@@ -114,13 +114,17 @@ class EventHook(object):
""" Event hook class. It consists of one conditionss and
one or multiple actions to be executed """
- def __init__(self, name, condition=None, actions=[]):
+ def __init__(self, name, priority=None, condition=None, actions=[]):
""" Construtor. Takes a name, a EventCondition object and a list of
- EventAction objects as input """
+ EventAction objects as input. It may also have a priority attached
+ as a positive number. If multiple hooks match against an event,
+ only the ones that have either the maximum match score or the
+ maximum pre-configured priority will be run. """
self.name = name
self.condition = EventCondition.build(condition or {})
self.actions = actions
+ self.priority = priority or 0
@classmethod
@@ -134,13 +138,15 @@ class EventHook(object):
condition = EventCondition.build(hook['if']) if 'if' in hook else None
actions = []
+ priority = hook['priority'] if 'priority' in hook else None
+
if 'then' in hook:
if isinstance(hook['then'], list):
actions = [EventAction.build(action) for action in hook['then']]
else:
actions = [EventAction.build(hook['then'])]
- return cls(name=name, condition=condition, actions=actions)
+ return cls(name=name, condition=condition, actions=actions, priority=priority)
def matches_event(self, event):
diff --git a/platypush/event/processor/__init__.py b/platypush/event/processor/__init__.py
index 06ce12e63..6753ab8a7 100644
--- a/platypush/event/processor/__init__.py
+++ b/platypush/event/processor/__init__.py
@@ -27,17 +27,23 @@ class EventProcessor(object):
def process_event(self, event):
""" Processes an event and runs the matched hooks with the highest score """
- matched_hooks = []
- max_score = -sys.maxsize
+ matched_hooks = set(); priority_hooks = set()
+ max_score = -sys.maxsize; max_prio = 0
for hook in self.hooks:
match = hook.matches_event(event)
if match.is_match:
if match.score > max_score:
- matched_hooks = [hook]
+ matched_hooks = set((hook,))
elif match.score == max_score:
- matched_hooks.append(hook)
+ matched_hooks.add(hook)
+ if hook.priority > max_prio:
+ priority_hooks = set((hook,))
+ elif hook.priority == max_prio:
+ priority_hooks.add(hook)
+
+ matched_hooks.update(priority_hooks)
for hook in matched_hooks:
hook.run(event)