Add database_backup.py for rotated database backups

.gitignore

@@ -66,3 +66,5 @@ target/
 *.conf
 modules/nongit-*.py
 bot.log.*
+bot.db.*
+test-databases/*

modules/database_backup.py

@@ -0,0 +1,28 @@
+import datetime, glob, os, shutil, time
+
+BACKUP_INTERVAL = 60*60 # 1 hour
+BACKUP_COUNT = 5
+
+class Module(object):
+    def __init__(self, bot, events, exports):
+        self.bot = bot
+        now = datetime.datetime.now()
+        until_next_hour = 60-now.second
+        until_next_hour += ((60-(now.minute+1))*60)
+
+        events.on("timer").on("database-backup").hook(self.backup)
+        bot.add_timer("database-backup", BACKUP_INTERVAL, persist=False,
+            next_due=time.time()+until_next_hour)
+
+    def backup(self, event):
+        files = glob.glob("%s.*" % self.bot.args.database)
+        files = sorted(files)
+
+        if len(files) == 5:
+            os.remove(files[0])
+
+        suffix = datetime.datetime.now().strftime("%y-%m-%d.%H:%M:%S")
+        backup_file = "%s.%s" % (self.bot.args.database, suffix)
+        shutil.copy2(self.bot.args.database, backup_file)
+
+        event["timer"].redo()