- Added a PID lock file class

git-svn-id: https://fail2ban.svn.sourceforge.net/svnroot/fail2ban/branches/FAIL2BAN-0_5@168 a942ae1a-1317-0410-a47c-b1dcaea8d605

utils/pidlock.py

@@ -0,0 +1,98 @@
+# This file is part of Fail2Ban.
+#
+# Fail2Ban is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# Fail2Ban is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Fail2Ban; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+# Author: Cyril Jaquier
+# 
+# $Revision$
+
+__author__ = "Cyril Jaquier"
+__version__ = "$Revision$"
+__date__ = "$Date$"
+__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
+__license__ = "GPL"
+
+import os, logging
+
+# Gets the instance of the logger.
+logSys = logging.getLogger("fail2ban")
+
+class PIDLock:
+	""" Manages the PID lock file.
+	
+		The following class shows how to implement the singleton pattern[1] in
+		Python. A singleton is a class that makes sure only one instance of it
+		is ever created. Typically such classes are used to manage resources
+		that by their very nature can only exist once.
+		
+		http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52558
+	"""
+	
+	class __impl:
+		""" Implementation of the singleton interface """
+
+		def setPath(self, path):
+			""" Set PID lock file path.
+			"""
+			self.path = path
+		
+		def create(self):
+			""" Create PID lock.
+			"""
+			fileHandler = open(self.path, mode='w')
+			pid = os.getpid()
+			fileHandler.write(`pid` + '\n')
+			fileHandler.close()
+			logSys.debug("Created PID lock (" + `pid` + ") in " + self.path)
+		
+		def remove(self):
+			""" Remove PID lock.
+			"""
+			os.remove(self.path)
+			logSys.debug("Removed PID lock " + self.path)
+		
+		def exists(self):
+			""" Returns the current PID if Fail2Ban is running or False
+				if no instance found.
+			"""
+			try:
+				fileHandler = open(self.path)
+				pid = fileHandler.readline()
+				fileHandler.close()
+				return pid
+			except IOError:
+				return False
+
+	# storage for the instance reference
+	__instance = None
+
+	def __init__(self):
+		""" Create singleton instance """
+		# Check whether we already have an instance
+		if PIDLock.__instance is None:
+			# Create and remember instance
+			PIDLock.__instance = PIDLock.__impl()
+
+		# Store instance reference as the only member in the handle
+		self.__dict__['_PIDLock__instance'] = PIDLock.__instance
+
+	def __getattr__(self, attr):
+		""" Delegate access to implementation """
+		return getattr(self.__instance, attr)
+
+	def __setattr__(self, attr, value):
+		""" Delegate access to implementation """
+		return setattr(self.__instance, attr, value)
+	

utils/process.py

@@ -30,10 +30,10 @@ import os, logging, signal
 logSys = logging.getLogger("fail2ban")
 
 def createDaemon():
-	"""Detach a process from the controlling terminal and run it in the
-	background as a daemon.
+	""" Detach a process from the controlling terminal and run it in the
+		background as a daemon.
 	
-	http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/278731
+		http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/278731
 	"""
 
 	try:
@@ -101,35 +101,6 @@ def createDaemon():
 	os.open("/dev/null", os.O_RDWR)		# standard error (2)
 
 	return True
-	
-def checkForPID(lockfile):
-	""" Checks for running Fail2Ban.
-	
-		Returns the current PID if Fail2Ban is running or False
-		if no instance found.
-	"""
-	try:
-		fileHandler = open(lockfile)
-		pid = fileHandler.readline()
-		fileHandler.close()
-		return pid
-	except IOError:
-		return False
-		
-def createPID(lockfile):
-	""" Creates a PID lock file with the current PID.
-	"""
-	fileHandler = open(lockfile, mode='w')
-	pid = os.getpid()
-	fileHandler.write(`pid`+'\n')
-	fileHandler.close()
-	logSys.debug("Created PID lock ("+`pid`+") in "+lockfile)
-		
-def removePID(lockfile):
-	""" Remove PID lock.
-	"""
-	os.remove(lockfile)
-	logSys.debug("Removed PID lock "+lockfile)
 
 def killPID(pid):
 	""" Kills the process with the given PID using the