1 files changed, 274 insertions, 0 deletions
diff --git a/portato/config_parser.py b/portato/config_parser.py
new file mode 100644
index 0000000..8418a6a
--- /dev/null
+++ b/portato/config_parser.py
@@ -0,0 +1,274 @@
+# -*- coding: utf-8 -*-
+#
+# File: portato/config_parser.py
+# This file is part of the Portato-Project, a graphical portage-frontend.
+#
+# Copyright (C) 2006 René 'Necoro' Neumann
+# This is free software.  You may redistribute copies of it under the terms of
+# the GNU General Public License version 2.
+# There is NO WARRANTY, to the extent permitted by law.
+#
+# Written by René 'Necoro' Neumann <necoro@necoro.net>
+
+from helper import debug
+
+import re
+import types
+
+DELIMITER = ["=", ":"]
+COMMENT = [";","#"]
+
+# precompiled expressions
+TRUE = re.compile("((true)|(1)|(on)|(wahr)|(ja)|(yes))", re.I)
+FALSE = re.compile("((false)|(0)|(off)|(falsch)|(nein)|(no))", re.I)
+SECTION = re.compile("\s*\[(\w+)\]\s*")
+EXPRESSION = re.compile(r"\s*(\w+)\s*[:=]\s*(.*)\s*")
+
+class Value (object):
+	"""Class defining a value of a key."""
+
+	def __init__ (self, value, line, bool = None):
+		"""Constructor.
+
+		@param value: the value
+		@type value: string
+		@param line: the line in the config file
+		@type line: int
+		@param bool: boolean meaning of the value
+		@type bool: boolean"""
+
+		self.__value = value
+		self.line = line
+		self.boolean = bool
+		
+		self.changed = False # true if we changed it
+		self.old = value # keep the original one ... so if we change it back to this one, we do not have to write
+
+	def set (self, value):
+		"""Sets the value to a new one.
+		
+		@param value: new value
+		@type value: string"""
+
+		self.__value = value
+		
+		if value != self.old:
+			self.changed = True
+		else:
+			self.changed = False
+
+	def get (self):
+		"""Returns the actual value.
+		
+		@returns: the actual value
+		@rtype: string"""
+
+		return self.__value
+	
+	def is_bool (self):
+		"""Returns whether the actual value has a boolean meaning.
+		
+		@returns: True if the actual value can be interpreted as a boolean
+		@rtype: boolean"""
+
+		return (self.boolean != None)
+
+	def __str__ (self):
+		return str(self.__value)
+
+	def __repr__ (self):
+		return self.__str__()
+	
+	value = property(get,set)
+	
+class ConfigParser:
+	"""The newly implemented Config-Parser."""
+
+	# generates the complementary true-false-pairs
+	true_false = {
+				"true" 	: "false",
+				"1"		: "0",
+				"on"	: "off",
+				"yes"	: "no",
+				"ja"	: "nein",
+				"wahr"	: "falsch"}
+	true_false.update(zip(true_false.values(), true_false.keys()))
+
+	def __init__ (self, file):
+		"""Constructor.
+
+		@param file: the configuration file to open
+		@type file: string"""
+
+		self.file = file
+		self.__initialize()
+
+	def __initialize (self):
+		"""Private method which initializes our dictionaries."""
+
+		self.vars = {"MAIN": {}}
+		self.cache = None # file cache
+		self.pos = {} # stores the positions of the matches
+
+	def _invert (self, val):
+		"""Invertes a given boolean.
+
+		@param val: value to invert
+		@type val: string
+		@returns: inverted value
+		@rtype: string"""
+
+		return self.true_false[val.lower()]
+
+	def parse (self):
+		"""Parses the file."""
+
+		# read into cache
+		file = open(self.file, "r")
+		self.cache = file.readlines()
+		file.close()
+
+		# implicit first section is main
+		section = "MAIN"
+		count = -1
+		for line in self.cache:
+			count += 1
+
+			ls = line.strip()
+			if not ls: continue # empty
+			if ls[0] in COMMENT: continue # comment
+			
+			# look for a section
+			match = SECTION.search(line)
+			if match:
+				sec = match.group(1).upper()
+				if sec != section:
+					self.vars[sec] = {}
+					section = sec
+				continue
+
+			# look for an expression
+			match = EXPRESSION.search(line)
+			if match: 
+				val = match.group(2)
+				
+				# find the boolean value
+				bool = None
+				if TRUE.match(val):
+					bool = True
+				elif FALSE.match(val):
+					bool = False
+				
+				# insert
+				key = match.group(1).lower()
+				self.vars[section][key] = Value(val, count, bool = bool)
+				self.pos[count] = match.span(2)
+			else: # neither comment nor empty nor expression nor section => error
+				debug("Unrecognized line:",line)
+
+	def get (self, key, section = "MAIN"):
+		"""Returns the value of a given key in a section.
+
+		@param key: the key
+		@type key: string
+		@param section: the section
+		@type section: string
+		
+		@returns: value
+		@rtype: string
+		
+		@raises KeyError: if section or key could not be found"""
+
+		section = section.upper()
+		key = key.lower()
+		return self.vars[section][key].value
+
+	def get_boolean (self, key, section = "MAIN"):
+		"""Returns the boolean value of a given key in a section.
+
+		@param key: the key
+		@type key: string
+		@param section: the section
+		@type section: string
+		
+		@returns: value
+		@rtype: boolean
+		
+		@raises KeyError: if section or key could not be found
+		@raises ValueError: if key does not have a boolean value"""
+		
+		section = section.upper()
+		key = key.lower()
+
+		val = self.vars[section][key]
+
+		if val.is_bool():
+			return val.boolean
+
+		raise ValueError, "\"%s\" is not a boolean." % key
+
+	def set (self, key, value = "", section = "MAIN"):
+		"""Sets a new value of a given key in a section.
+
+		@param key: the key
+		@type key: string
+		@param value: the new value
+		@type value: string
+		@param section: the section
+		@type section: string
+		
+		@raises KeyError: if section or key could not be found"""
+		
+		section = section.upper()
+		key = key.lower()
+
+		self.vars[section][key].value = value
+
+	def set_boolean (self, key, value, section = "MAIN"):
+		"""Sets a new boolean value of a given key in a section.
+		Therefore it invertes the string representation of the boolean (in lowercase).
+
+		@param key: the key
+		@type key: string
+		@param value: the new value
+		@type value: boolean
+		@param section: the section
+		@type section: string
+		
+		@raises KeyError: if section or key could not be found
+		@raises ValueError: if the old/new value is not a boolean"""
+		
+		section = section.upper()
+		key = key.lower()
+		
+		if not isinstance(value, types.BooleanType):
+			raise ValueError, "Passed value must be a boolean."
+
+		val = self.vars[section][key]
+		if val.is_bool():
+			if value is not val.boolean:
+				val.boolean = value
+				val.value = self._invert(val.value)
+		else:
+			raise ValueError, "\"%s\" is not a boolean." % key
+
+	def write (self):
+		"""Writes file."""
+
+		for sec in self.vars:
+			for key in self.vars[sec]:
+				val = self.vars[sec][key]
+				if val.changed:
+					part1 = self.cache[val.line][:self.pos[val.line][0]] 	# key+DELIMITER
+					part2 = val.value										# value
+					part3 = self.cache[val.line][self.pos[val.line][1]:]	# everything behind the vale (\n in normal cases)
+					self.cache[val.line] = part1 + part2 + part3
+		
+		# write
+		f = open(self.file, "w")
+		f.writelines(self.cache)
+		f.close()
+
+		# reload
+		self.__initialize()
+		self.parse()