Topic plugin: Add persistence support.

Topics now persist between restarts.

Rationale: Useful when reloading/restarting; previously the topics would
be just forgotten. Don't use database, as that would be an unnecessary
overkill and in any case not needed.

(Also, remove the unused `re' module import.)

Signed-off-by: James Vega <jamessan@users.sourceforge.net>

plugins/Topic/__init__.py

@@ -42,7 +42,7 @@ __author__ = supybot.authors.jemfinch
 
 # This is a dictionary mapping supybot.Author instances to lists of
 # contributions.
-__contributors__ = {}
+__contributors__ = { supybot.authors.stepnem: ['persistence support'] }
 
 import config
 import plugin

plugins/Topic/plugin.py

@@ -27,17 +27,22 @@
 # POSSIBILITY OF SUCH DAMAGE.
 ###
 
-import re
+import os
 import random
+import shutil
+import tempfile
+import cPickle as pickle
 
 import supybot.conf as conf
+import supybot.ircdb as ircdb
 import supybot.utils as utils
+import supybot.world as world
 from supybot.commands import *
 import supybot.ircmsgs as ircmsgs
 import supybot.plugins as plugins
 import supybot.ircutils as ircutils
 import supybot.callbacks as callbacks
-import supybot.ircdb as ircdb
+
 
 def canChangeTopic(irc, msg, args, state):
     assert not state.channel
@@ -96,6 +101,9 @@ addConverter('canChangeTopic', canChangeTopic)
 def splitTopic(topic, separator):
     return filter(None, topic.split(separator))
 
+datadir = conf.supybot.directories.data()
+filename = conf.supybot.directories.data.dirize('Topic.pickle')
+
 class Topic(callbacks.Plugin):
     def __init__(self, irc):
         self.__parent = super(Topic, self)
@@ -104,6 +112,39 @@ class Topic(callbacks.Plugin):
         self.redos = ircutils.IrcDict()
         self.lastTopics = ircutils.IrcDict()
         self.watchingFor332 = ircutils.IrcSet()
+        try:
+            pkl = open(filename, 'rb')
+            try:
+                self.undos = pickle.load(pkl)
+                self.redos = pickle.load(pkl)
+                self.lastTopics = pickle.load(pkl)
+                self.watchingFor332 = pickle.load(pkl)
+            except Exception, e:
+                self.log.debug('Unable to load pickled data: %s', e)
+            pkl.close()
+        except IOError, e:
+            self.log.debug('Unable to open pickle file: %s', e)
+        world.flushers.append(self._flush)
+
+    def die(self):
+        world.flushers.remove(self._flush)
+        self.__parent.die()
+
+    def _flush(self):
+        try:
+            pklfd, tempfn = tempfile.mkstemp(suffix='topic', dir=datadir)
+            pkl = os.fdopen(pklfd, 'wb')
+            try:
+                pickle.dump(self.undos, pkl)
+                pickle.dump(self.redos, pkl)
+                pickle.dump(self.lastTopics, pkl)
+                pickle.dump(self.watchingFor332, pkl)
+            except Exception, e:
+                self.log.warning('Unable to store pickled data: %s', e)
+            pkl.close()
+            shutil.move(tempfn, filename)
+        except (IOError, shutil.Error), e:
+            self.log.warning('File error: %s', e)
 
     def _splitTopic(self, topic, channel):
         separator = self.registryValue('separator', channel)
@@ -165,10 +206,10 @@ class Topic(callbacks.Plugin):
     def _checkManageCapabilities(self, irc, msg, channel):
         """Check if the user has any of the required capabilities to manage
         the channel topic.
-        
+
         The list of required capabilities is in requireManageCapability
         channel config.
-        
+
         Also allow if the user is a chanop. Since he can change the topic
         manually anyway.
         """

src/__init__.py

@@ -1,3 +1,4 @@
+# coding: utf-8
 ###
 # Copyright (c) 2002-2005, Jeremiah Fincher
 # All rights reserved.
@@ -56,6 +57,7 @@ class authors(object): # This is basically a bag.
     bwp = Author('Brett Phipps', 'bwp', 'phippsb@gmail.com')
     bear = Author('Mike Taylor', 'bear', 'bear@code-bear.com')
     grantbow = Author('Grant Bowman', 'Grantbow', 'grantbow@grantbow.com')
+    stepnem = Author('Štěpán Němec', 'stepnem', 'stepnem@gmail.com')
     unknown = Author('Unknown author', 'unknown', 'unknown@supybot.org')
 
     # Let's be somewhat safe about this.