Merge branch 'improvements'

1 files changed, 347 insertions, 0 deletions

diff --git a/lib/git/config.py b/lib/git/config.py
new file mode 100644
index 00000000..ccfbae48
--- /dev/null
+++ b/lib/git/config.py
@@ -0,0 +1,347 @@
+# config.py
+# Copyright (C) 2008, 2009 Michael Trier (mtrier@gmail.com) and contributors
+#
+# This module is part of GitPython and is released under
+# the BSD License: http://www.opensource.org/licenses/bsd-license.php
+"""
+Module containing module parser implementation able to properly read and write
+configuration files
+"""
+
+import re
+import os
+import ConfigParser as cp
+import inspect
+import cStringIO
+
+from git.odict import OrderedDict
+from git.utils import LockFile
+
+class _MetaParserBuilder(type):
+	"""
+	Utlity class wrapping base-class methods into decorators that assure read-only properties
+	"""
+	def __new__(metacls, name, bases, clsdict):
+		"""
+		Equip all base-class methods with a _needs_values decorator, and all non-const methods
+		with a _set_dirty_and_flush_changes decorator in addition to that.
+		"""
+		mutating_methods = clsdict['_mutating_methods_']
+		for base in bases:
+			methods = ( t for t in inspect.getmembers(base, inspect.ismethod) if not t[0].startswith("_") )
+			for name, method in methods:
+				if name in clsdict:
+					continue
+				method_with_values = _needs_values(method)
+				if name in mutating_methods:
+					method_with_values = _set_dirty_and_flush_changes(method_with_values)
+				# END mutating methods handling
+				
+				clsdict[name] = method_with_values
+		# END for each base
+		
+		new_type = super(_MetaParserBuilder, metacls).__new__(metacls, name, bases, clsdict)
+		return new_type
+	
+	
+
+def _needs_values(func):
+	"""
+	Returns method assuring we read values (on demand) before we try to access them
+	"""
+	def assure_data_present(self, *args, **kwargs):
+		self.read()
+		return func(self, *args, **kwargs)
+	# END wrapper method
+	assure_data_present.__name__ = func.__name__
+	return assure_data_present
+	
+def _set_dirty_and_flush_changes(non_const_func):
+	"""
+	Return method that checks whether given non constant function may be called.
+	If so, the instance will be set dirty.
+	Additionally, we flush the changes right to disk
+	"""
+	def flush_changes(self, *args, **kwargs):
+		rval = non_const_func(self, *args, **kwargs)
+		self.write()
+		return rval
+	# END wrapper method
+	flush_changes.__name__ = non_const_func.__name__
+	return flush_changes
+	
+	
+
+class GitConfigParser(cp.RawConfigParser, LockFile):
+	"""
+	Implements specifics required to read git style configuration files.
+	
+	This variation behaves much like the git.config command such that the configuration
+	will be read on demand based on the filepath given during initialization.
+	
+	The changes will automatically be written once the instance goes out of scope, but 
+	can be triggered manually as well.
+	
+	The configuration file will be locked if you intend to change values preventing other 
+	instances to write concurrently.
+	
+	NOTE
+		The config is case-sensitive even when queried, hence section and option names
+		must match perfectly.
+	"""
+	__metaclass__ = _MetaParserBuilder
+	
+	OPTCRE = re.compile(
+		r'\s?(?P<option>[^:=\s][^:=]*)'		  # very permissive, incuding leading whitespace
+		r'\s*(?P<vi>[:=])\s*'				  # any number of space/tab,
+											  # followed by separator
+											  # (either : or =), followed
+											  # by any # space/tab
+		r'(?P<value>.*)$'					  # everything up to eol
+		)
+	
+	# list of RawConfigParser methods able to change the instance
+	_mutating_methods_ = ("add_section", "remove_section", "remove_option", "set")
+	__slots__ = ("_sections", "_defaults", "_file_or_files", "_read_only","_is_initialized")
+	
+	def __init__(self, file_or_files, read_only=True):
+		"""
+		Initialize a configuration reader to read the given file_or_files and to 
+		possibly allow changes to it by setting read_only False
+		
+		``file_or_files``
+			A single file path or file objects or multiple of these
+		
+		``read_only``
+			If True, the ConfigParser may only read the data , but not change it.
+			If False, only a single file path or file object may be given.
+		"""
+		# initialize base with ordered dictionaries to be sure we write the same 
+		# file back 
+		self._sections = OrderedDict()
+		self._defaults = OrderedDict()
+		
+		self._file_or_files = file_or_files
+		self._read_only = read_only
+		self._is_initialized = False
+		
+		
+		if not read_only:
+			if isinstance(file_or_files, (tuple, list)):
+				raise ValueError("Write-ConfigParsers can operate on a single file only, multiple files have been passed")
+			# END single file check
+			
+			if not isinstance(file_or_files, basestring):
+				file_or_files = file_or_files.name
+			# END get filename from handle/stream
+			# initialize lock base - we want to write
+			LockFile.__init__(self, file_or_files)
+			
+			self._obtain_lock_or_raise()	
+		# END read-only check
+		
+	
+	def __del__(self):
+		"""
+		Write pending changes if required and release locks
+		"""
+		# checking for the lock here makes sure we do not raise during write()
+		# in case an invalid parser was created who could not get a lock
+		if self.read_only or not self._has_lock():
+			return
+		
+		try:
+			try:
+				self.write()
+			except IOError,e:
+				print "Exception during destruction of GitConfigParser: %s" % str(e)
+		finally:
+			self._release_lock()
+	
+	def optionxform(self, optionstr):
+		"""
+		Do not transform options in any way when writing
+		"""
+		return optionstr
+	
+	def _read(self, fp, fpname):
+		"""
+		A direct copy of the py2.4 version of the super class's _read method
+		to assure it uses ordered dicts. Had to change one line to make it work.
+		
+		Future versions have this fixed, but in fact its quite embarassing for the 
+		guys not to have done it right in the first place !
+		
+		Removed big comments to make it more compact.
+		
+		Made sure it ignores initial whitespace as git uses tabs
+		"""
+		cursect = None							  # None, or a dictionary
+		optname = None
+		lineno = 0
+		e = None								  # None, or an exception
+		while True:
+			line = fp.readline()
+			if not line:
+				break
+			lineno = lineno + 1
+			# comment or blank line?
+			if line.strip() == '' or line[0] in '#;':
+				continue
+			if line.split(None, 1)[0].lower() == 'rem' and line[0] in "rR":
+				# no leading whitespace
+				continue
+			else:
+				# is it a section header?
+				mo = self.SECTCRE.match(line)
+				if mo:
+					sectname = mo.group('header')
+					if sectname in self._sections:
+						cursect = self._sections[sectname]
+					elif sectname == cp.DEFAULTSECT:
+						cursect = self._defaults
+					else:
+						# THE ONLY LINE WE CHANGED !
+						cursect = OrderedDict((('__name__', sectname),))
+						self._sections[sectname] = cursect
+					# So sections can't start with a continuation line
+					optname = None
+				# no section header in the file?
+				elif cursect is None:
+					raise cp.MissingSectionHeaderError(fpname, lineno, line)
+				# an option line?
+				else:
+					mo = self.OPTCRE.match(line)
+					if mo:
+						optname, vi, optval = mo.group('option', 'vi', 'value')
+						if vi in ('=', ':') and ';' in optval:
+							pos = optval.find(';')
+							if pos != -1 and optval[pos-1].isspace():
+								optval = optval[:pos]
+						optval = optval.strip()
+						if optval == '""':
+							optval = ''
+						optname = self.optionxform(optname.rstrip())
+						cursect[optname] = optval
+					else:
+						if not e:
+							e = cp.ParsingError(fpname)
+						e.append(lineno, repr(line))
+					# END  
+				# END ? 
+			# END ?
+		# END while reading 
+		# if any parsing errors occurred, raise an exception
+		if e:
+			raise e
+	
+	
+	def read(self):
+		"""
+		Reads the data stored in the files we have been initialized with. It will 
+		ignore files that cannot be read, possibly leaving an empty configuration
+		
+		Returns
+			Nothing
+		
+		Raises
+			IOError if a file cannot be handled
+		"""
+		if self._is_initialized:
+			return
+			
+		
+		files_to_read = self._file_or_files
+		if not isinstance(files_to_read, (tuple, list)):
+			files_to_read = [ files_to_read ]
+		
+		for file_object in files_to_read:
+			fp = file_object
+			close_fp = False
+			# assume a path if it is not a file-object
+			if not hasattr(file_object, "seek"):
+				try:
+					fp = open(file_object)
+				except IOError,e:
+					continue
+				close_fp = True
+			# END fp handling
+				
+			try:
+				self._read(fp, fp.name)
+			finally:
+				if close_fp:
+					fp.close()
+			# END read-handling
+		# END  for each file object to read
+		self._is_initialized = True
+		
+	def _write(self, fp):
+		"""Write an .ini-format representation of the configuration state in 
+		git compatible format"""
+		def write_section(name, section_dict):
+			fp.write("[%s]\n" % name)
+			for (key, value) in section_dict.items():
+				if key != "__name__":
+					fp.write("\t%s = %s\n" % (key, str(value).replace('\n', '\n\t')))
+				# END if key is not __name__
+		# END section writing 
+		
+		if self._defaults:
+			write_section(cp.DEFAULTSECT, self._defaults)
+		map(lambda t: write_section(t[0],t[1]), self._sections.items())
+
+		
+	@_needs_values
+	def write(self):
+		"""
+		Write changes to our file, if there are changes at all
+		
+		Raise
+			IOError if this is a read-only writer instance or if we could not obtain 
+			a file lock
+		"""
+		self._assure_writable("write")
+		self._obtain_lock_or_raise()
+		
+		
+		fp = self._file_or_files
+		close_fp = False
+		
+		if not hasattr(fp, "seek"):
+			fp = open(self._file_or_files, "w")
+			close_fp = True
+		else:
+			fp.seek(0)
+		
+		# WRITE DATA
+		try:
+			self._write(fp)
+		finally:
+			if close_fp:
+				fp.close()
+		# END data writing
+			
+		# we do not release the lock - it will be done automatically once the 
+		# instance vanishes
+		
+	def _assure_writable(self, method_name):
+		if self.read_only:
+			raise IOError("Cannot execute non-constant method %s.%s" % (self, method_name))
+		
+	@_needs_values
+	@_set_dirty_and_flush_changes
+	def add_section(self, section):
+		"""
+		Assures added options will stay in order
+		"""
+		super(GitConfigParser, self).add_section(section)
+		self._sections[section] = OrderedDict()
+		
+	@property
+	def read_only(self):
+		"""
+		Returns
+			True if this instance may change the configuration file
+		"""
+		return self._read_only