From 714458fd079343ac9698436d3c7fcc4203b7d41f Mon Sep 17 00:00:00 2001
From: Narayan Desai <desai@mcs.anl.gov>
Date: Thu, 1 Dec 2005 21:40:48 +0000
Subject: change to event coalescing

git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@1605 ce84e21b-d406-0410-9b95-82705330c041
---
 src/lib/Server/Core.py | 99 ++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 71 insertions(+), 28 deletions(-)

(limited to 'src/lib/Server/Core.py')

diff --git a/src/lib/Server/Core.py b/src/lib/Server/Core.py
index 979d86f5f..a2100ea53 100644
--- a/src/lib/Server/Core.py
+++ b/src/lib/Server/Core.py
@@ -65,12 +65,37 @@ class FamFam(object):
     def Service(self):
         '''Handle all fam work'''
         count = 0
-        t1 = time()
-        while self.fm.pending():
-            count += 1
-            self.HandleEvent()
-        t2 = time()
-        syslog(LOG_INFO, "Processed %s fam events in %s seconds" % (count, (t2 - t1)))
+        collapsed = 0
+        rawevents = []
+        start = time()
+        now = time()
+        while (time() - now) < 0.10:
+            if self.fm.pending():
+                while self.fm.pending():
+                    count += 1
+                    rawevents.append(self.fm.nextEvent())
+                now = time()
+        unique = []
+        bookkeeping = []
+        for event in rawevents:
+            if event.code2str() != 'changed':
+                # process all non-change events
+                unique.append(event)
+            else:
+                if (event.filename, event.requestID) not in bookkeeping:
+                    bookkeeping.append((event.filename, event.requestID))
+                    unique.append(event)
+                else:
+                    collapsed += 1
+        for event in unique:
+            if self.users.has_key(event.requestID):
+                try:
+                    self.users[event.requestID].HandleEvent(event)
+                except:
+                    log_failure("handling event for file %s" % (event.filename))
+        end = time()
+        syslog(LOG_INFO, "Processed %s fam events in %03.03f seconds. %s coalesced" %
+               (count, (end - start), collapsed))
 
 class GaminEvent(object):
     '''This class provides an event analogous to python-fam events based on gamin sources'''
@@ -93,20 +118,15 @@ class GaminFam(object):
         self.mon = WatchMonitor()
         self.handles = {}
         self.counter = 0
+        self.events = []
 
     def fileno(self):
         '''return fam file handle number'''
         return self.mon.get_fd()
 
-    def dispatch(self, path, action, request_id):
-        '''find the right object to dispatch to'''
-        if self.handles.has_key(request_id):
-            evt = GaminEvent(request_id, path, action)
-            #print "e %s %s to obj %s handle :%s:" % (evt.code2str(), evt.filename,
-            #                                         self.handles[request_id], evt.requestID)
-            self.handles[request_id].HandleEvent(evt)
-        else:
-            print "got crazy event for nonexistant handle %s" % request_id
+    def queue(self, path, action, request_id):
+        '''queue up the event for later handling'''
+        self.events.append(GaminEvent(request_id, path, action))
 
     def AddMonitor(self, path, obj):
         '''add a monitor to path, installing a callback to obj.HandleEvent'''
@@ -114,26 +134,49 @@ class GaminFam(object):
         self.counter += 1
         mode = stat(path)[ST_MODE]
         if S_ISDIR(mode):
-            self.mon.watch_directory(path, self.dispatch, handle)
+            self.mon.watch_directory(path, self.queue, handle)
             #print "adding callback for directory %s to %s, handle :%s:" % ( path, obj, handle.requestID())
         else:
-            self.mon.watch_file(path, self.dispatch, handle)
+            self.mon.watch_file(path, self.queue, handle)
         self.handles[handle] = obj
         return handle
 
-    def HandleEvent(self):
-        '''Call Gamin, which will call the callback'''
-        self.mon.handle_one_event()
-
     def Service(self):
-        '''Handle any pending Gamin work'''
+        '''Handle all gamin work'''
         count = 0
-        t1 = time()
-        while self.mon.event_pending():
-            count += 1
-            self.mon.handle_one_event()
-        t2 = time()
-        syslog(LOG_INFO, "Processed %s gamin events in %s seconds" % (count, (t2 - t1)))
+        collapsed = 0
+        start = time()
+        now = time()
+        while (time() - now) < 0.10:
+            if self.mon.event_pending():
+                while self.mon.event_pending():
+                    count += 1
+                    self.mon.handle_one_event()
+                now = time()
+        unique = []
+        bookkeeping = []
+        for event in self.events:
+            if event.code2str() != 'changed':
+                # process all non-change events
+                unique.append(event)
+            else:
+                if (event.filename, event.requestID) not in bookkeeping:
+                    bookkeeping.append((event.filename, event.requestID))
+                    unique.append(event)
+                else:
+                    collapsed += 1
+        self.events = []
+        for event in unique:
+            if self.handles.has_key(event.requestID):
+                try:
+                    self.handles[event.requestID].HandleEvent(event)
+                except:
+                    log_failure("handling of gamin event for %s" % (event.filename))
+            else:
+                syslog(LOG_INFO, "Got event for unexpected id %s, file %s" % (event.requestID, event.filename))
+        end = time()
+        syslog(LOG_INFO, "Processed %s gamin events in %03.03f seconds. %s collapsed" %
+               (count, (end - start), collapsed))
         
 try:
     from gamin import WatchMonitor, GAMCreated, GAMExists, GAMEndExist, GAMChanged, GAMDeleted
-- 
cgit v1.2.3-1-g7c22