def updateprotect(self):
		"""Update internal state for isprotected() calls.  Nonexistent paths
		are ignored."""

		os = _os_merge

		self.protect = []
		self._dirs = set()
		for x in self.protect_list:
			ppath = normalize_path(
				os.path.join(self.myroot, x.lstrip(os.path.sep)))
			try:
				if stat.S_ISDIR(os.stat(ppath).st_mode):
					self._dirs.add(ppath)
				self.protect.append(ppath)
			except OSError:
				# If it doesn't exist, there's no need to protect it.
				pass

		self.protectmask = []
		for x in self.mask_list:
			ppath = normalize_path(
				os.path.join(self.myroot, x.lstrip(os.path.sep)))
			try:
				"""Use lstat so that anything, even a broken symlink can be
				protected."""
				if stat.S_ISDIR(os.lstat(ppath).st_mode):
					self._dirs.add(ppath)
				self.protectmask.append(ppath)
				"""Now use stat in case this is a symlink to a directory."""
				if stat.S_ISDIR(os.stat(ppath).st_mode):
					self._dirs.add(ppath)
			except OSError:
				# If it doesn't exist, there's no need to mask it.
				pass

	def _same_device(path1, path2):
		try:
			st1 = os.stat(path1)
			st2 = os.stat(path2)
		except OSError:
			return False
		else:
			return st1.st_dev == st2.st_dev

def exists_raise_eaccess(path):
	try:
		os.stat(path)
	except OSError as e:
		if e.errno == PermissionDenied.errno:
			raise PermissionDenied("stat('%s')" % path)
		return False
	else:
		return True

def cacheddir(my_original_path, ignorecvs, ignorelist, EmptyOnError, followSymlinks=True):
	mypath = normalize_path(my_original_path)
	try:
		pathstat = os.stat(mypath)
		if not stat.S_ISDIR(pathstat.st_mode):
			raise DirectoryNotFound(mypath)
	except EnvironmentError as e:
		if e.errno == PermissionDenied.errno:
			raise PermissionDenied(mypath)
		del e
		return [], []
	except PortageException:
		return [], []
	else:
		try:
			fpaths = os.listdir(mypath)
		except EnvironmentError as e:
			if e.errno != errno.EACCES:
				raise
			del e
			raise PermissionDenied(mypath)
		ftype = []
		for x in fpaths:
			try:
				if followSymlinks:
					pathstat = os.stat(mypath+"/"+x)
				else:
					pathstat = os.lstat(mypath+"/"+x)

				if stat.S_ISREG(pathstat[stat.ST_MODE]):
					ftype.append(0)
				elif stat.S_ISDIR(pathstat[stat.ST_MODE]):
					ftype.append(1)
				elif stat.S_ISLNK(pathstat[stat.ST_MODE]):
					ftype.append(2)
				else:
					ftype.append(3)
			except (IOError, OSError):
				ftype.append(3)

	if ignorelist or ignorecvs:
		ret_list = []
		ret_ftype = []
		for file_path, file_type in zip(fpaths, ftype):
			if file_path in ignorelist:
				pass
			elif ignorecvs:
				if file_path[:2] != ".#" and \
					not (file_type == 1 and file_path in VCS_DIRS):
					ret_list.append(file_path)
					ret_ftype.append(file_type)
	else:
		ret_list = fpaths
		ret_ftype = ftype

	return ret_list, ret_ftype

	def getfetchsizes(self, mypkg, useflags=None, debug=0, myrepo=None):
		# returns a filename:size dictionnary of remaining downloads
		myebuild, mytree = self.findname2(mypkg, myrepo=myrepo)
		if myebuild is None:
			raise AssertionError(_("ebuild not found for '%s'") % mypkg)
		pkgdir = os.path.dirname(myebuild)
		mf = self.repositories.get_repo_for_location(
			os.path.dirname(os.path.dirname(pkgdir))).load_manifest(
				pkgdir, self.settings["DISTDIR"])
		checksums = mf.getDigests()
		if not checksums:
			if debug: 
				writemsg(_("[empty/missing/bad digest]: %s\n") % (mypkg,))
			return {}
		filesdict={}
		myfiles = self.getFetchMap(mypkg, useflags=useflags, mytree=mytree)
		#XXX: maybe this should be improved: take partial downloads
		# into account? check checksums?
		for myfile in myfiles:
			try:
				fetch_size = int(checksums[myfile]["size"])
			except (KeyError, ValueError):
				if debug:
					writemsg(_("[bad digest]: missing %(file)s for %(pkg)s\n") % {"file":myfile, "pkg":mypkg})
				continue
			file_path = os.path.join(self.settings["DISTDIR"], myfile)
			mystat = None
			try:
				mystat = os.stat(file_path)
			except OSError:
				pass
			if mystat is None:
				existing_size = 0
				ro_distdirs = self.settings.get("PORTAGE_RO_DISTDIRS")
				if ro_distdirs is not None:
					for x in shlex_split(ro_distdirs):
						try:
							mystat = os.stat(os.path.join(x, myfile))
						except OSError:
							pass
						else:
							if mystat.st_size == fetch_size:
								existing_size = fetch_size
								break
			else:
				existing_size = mystat.st_size
			remaining_size = fetch_size - existing_size
			if remaining_size > 0:
				# Assume the download is resumable.
				filesdict[myfile] = remaining_size
			elif remaining_size < 0:
				# The existing file is too large and therefore corrupt.
				filesdict[myfile] = int(checksums[myfile]["size"])
		return filesdict

	def load(self):
		atoms = []
		nonatoms = []
		atoms_changed = False
		# load atoms and non-atoms from different files so the worldfile is 
		# backwards-compatible with older versions and other PMs, even though 
		# it's supposed to be private state data :/
		try:
			mtime = os.stat(self._filename).st_mtime
		except (OSError, IOError):
			mtime = None
		if (not self._loaded or self._mtime != mtime):
			try:
				data, errors = self.loader.load()
				for fname in errors:
					for e in errors[fname]:
						self.errors.append(fname+": "+e)
			except EnvironmentError as e:
				if e.errno != errno.ENOENT:
					raise
				del e
				data = {}
			atoms = list(data)
			self._mtime = mtime
			atoms_changed = True
		else:
			atoms.extend(self._atoms)
		try:
			mtime = os.stat(self._filename2).st_mtime
		except (OSError, IOError):
			mtime = None
		if (not self._loaded or self._mtime2 != mtime):
			try:
				data, errors = self.loader2.load()
				for fname in errors:
					for e in errors[fname]:
						self.errors.append(fname+": "+e)
			except EnvironmentError as e:
				if e.errno != errno.ENOENT:
					raise
				del e
				data = {}
			nonatoms = list(data)
			self._mtime2 = mtime
			atoms_changed = True
		else:
			nonatoms.extend(self._nonatoms)
		if atoms_changed:
			self._setAtoms(atoms+nonatoms)

def grab_updates(updpath, prev_mtimes=None):
	"""Returns all the updates from the given directory as a sorted list of
	tuples, each containing (file_path, statobj, content).  If prev_mtimes is
	given then only updates with differing mtimes are considered."""
	try:
		mylist = os.listdir(updpath)
	except OSError as oe:
		if oe.errno == errno.ENOENT:
			raise DirectoryNotFound(updpath)
		raise
	if prev_mtimes is None:
		prev_mtimes = {}
	# validate the file name (filter out CVS directory, etc...)
	mylist = [myfile for myfile in mylist if len(myfile) == 7 and myfile[1:3] == "Q-"]
	if len(mylist) == 0:
		return []
	
	# update names are mangled to make them sort properly
	mylist = [myfile[3:]+"-"+myfile[:2] for myfile in mylist]
	mylist.sort()
	mylist = [myfile[5:]+"-"+myfile[:4] for myfile in mylist]

	update_data = []
	for myfile in mylist:
		file_path = os.path.join(updpath, myfile)
		mystat = os.stat(file_path)
		if file_path not in prev_mtimes or \
		long(prev_mtimes[file_path]) != mystat[stat.ST_MTIME]:
			content = codecs.open(_unicode_encode(file_path,
				encoding=_encodings['fs'], errors='strict'),
				mode='r', encoding=_encodings['repo.content'], errors='replace'
				).read()
			update_data.append((file_path, mystat, content))
	return update_data

 def load(self):
     try:
         mtime = os.stat(self._filename).st_mtime
     except (OSError, IOError):
         mtime = None
     if not self._loaded or self._mtime != mtime:
         try:
             data, errors = self.loader.load()
             for fname in errors:
                 for e in errors[fname]:
                     self.errors.append(fname + ": " + e)
         except EnvironmentError as e:
             if e.errno != errno.ENOENT:
                 raise
             del e
             data = {}
         if self.greedy:
             atoms = []
             for a in data:
                 matches = self.dbapi.match(a)
                 for cpv in matches:
                     atoms.append("%s:%s" % (cpv_getkey(cpv), self.dbapi.aux_get(cpv, ["SLOT"])[0]))
                     # In addition to any installed slots, also try to pull
                     # in the latest new slot that may be available.
                 atoms.append(a)
         else:
             atoms = iter(data)
         self._setAtoms(atoms)
         self._mtime = mtime

	def sync_timestamp(self):
			# If possible, update the mtime to match the remote package if
			# the fetcher didn't already do it automatically.
			bintree = self.pkg.root_config.trees["bintree"]
			if bintree._remote_has_index:
				remote_mtime = bintree._remotepkgs[
					bintree.dbapi._instance_key(
					self.pkg.cpv)].get("_mtime_")
				if remote_mtime is not None:
					try:
						remote_mtime = long(remote_mtime)
					except ValueError:
						pass
					else:
						try:
							local_mtime = os.stat(self.pkg_path)[stat.ST_MTIME]
						except OSError:
							pass
						else:
							if remote_mtime != local_mtime:
								try:
									os.utime(self.pkg_path,
										(remote_mtime, remote_mtime))
								except OSError:
									pass

	def __getattr__(self, attr):
		if attr == 'mtime':
			# use stat.ST_MTIME; accessing .st_mtime gets you a float
			# depending on the python version, and long(float) introduces
			# some rounding issues that aren't present for people using
			# the straight c api.
			# thus use the defacto python compatibility work around;
			# access via index, which guarantees you get the raw long.
			try:
				self.mtime = obj = os.stat(self.location)[stat.ST_MTIME]
			except OSError as e:
				if e.errno in (errno.ENOENT, errno.ESTALE):
					raise FileNotFound(self.location)
				elif e.errno == PermissionDenied.errno:
					raise PermissionDenied(self.location)
				raise
			return obj
		if not attr.islower():
			# we don't care to allow .mD5 as an alias for .md5
			raise AttributeError(attr)
		hashname = attr.upper()
		if hashname not in checksum.hashfunc_map:
			raise AttributeError(attr)
		val = checksum.perform_checksum(self.location, hashname)[0]
		setattr(self, attr, val)
		return val

	def _apply_max_mtime(self, existing_st, entries):
		"""
		Set the Manifest mtime to the max mtime of all relevant files
		(the existing Manifest mtime is included in order to account for
		eclass modifications that change DIST entries). This results in a
		stable/predictable mtime, which is useful when converting thin
		manifests to thick manifests for distribution via rsync. For
		portability, the mtime is set with 1 second resolution.

		@param existing_st: stat result for existing Manifest
		@type existing_st: posix.stat_result
		@param entries: list of current Manifest2Entry instances
		@type entries: list
		"""
		# Use stat_result[stat.ST_MTIME] for 1 second resolution, since
		# it always rounds down. Note that stat_result.st_mtime will round
		# up from 0.999999999 to 1.0 when precision is lost during conversion
		# from nanosecond resolution to float.
		max_mtime = None if existing_st is None else existing_st[stat.ST_MTIME]
		for entry in entries:
			if entry.type == 'DIST':
				continue
			abs_path = (os.path.join(self.pkgdir, 'files', entry.name) if
				entry.type == 'AUX' else os.path.join(self.pkgdir, entry.name))
			mtime = os.stat(abs_path)[stat.ST_MTIME]
			if max_mtime is None or mtime > max_mtime:
				max_mtime = mtime

		if max_mtime is not None:
			os.utime(self.getFullname(), (max_mtime, max_mtime))

	def close(self):
		"""Closes the temporary file, copies permissions (if possible),
		and performs the atomic replacement via os.rename().  If the abort()
		method has been called, then the temp file is closed and removed."""
		f = object.__getattribute__(self, '_file')
		real_name = object.__getattribute__(self, '_real_name')
		if not f.closed:
			try:
				f.close()
				if not object.__getattribute__(self, '_aborted'):
					try:
						apply_stat_permissions(f.name, os.stat(real_name))
					except OperationNotPermitted:
						pass
					except FileNotFound:
						pass
					except OSError as oe: # from the above os.stat call
						if oe.errno in (errno.ENOENT, errno.EPERM):
							pass
						else:
							raise
					os.rename(f.name, real_name)
			finally:
				# Make sure we cleanup the temp file
				# even if an exception is raised.
				try:
					os.unlink(f.name)
				except OSError as oe:
					pass

def _check_distfile(filename, digests, eout, show_errors=1):
	"""
	@return a tuple of (match, stat_obj) where match is True if filename
	matches all given digests (if any) and stat_obj is a stat result, or
	None if the file does not exist.
	"""
	if digests is None:
		digests = {}
	size = digests.get("size")
	if size is not None and len(digests) == 1:
		digests = None

	try:
		st = os.stat(filename)
	except OSError:
		return (False, None)
	if size is not None and size != st.st_size:
		return (False, st)
	if not digests:
		if size is not None:
			eout.ebegin(_("%s size ;-)") % os.path.basename(filename))
			eout.eend(0)
		elif st.st_size == 0:
			# Zero-byte distfiles are always invalid.
			return (False, st)
	else:
		if _check_digests(filename, digests, show_errors=show_errors):
			eout.ebegin("%s %s ;-)" % (os.path.basename(filename),
				" ".join(sorted(digests))))
			eout.eend(0)
		else:
			return (False, st)
	return (True, st)

def verify_all(filename, mydict, calc_prelink=0, strict=0):
    """
	Verify all checksums against a file.

	@param filename: File to run the checksums against
	@type filename: String
	@param calc_prelink: Whether or not to reverse prelink before running the checksum
	@type calc_prelink: Integer
	@param strict: Enable/Disable strict checking (which stops exactly at a checksum failure and throws an exception)
	@type strict: Integer
	@rtype: Tuple
	@return: Result of the checks and possible message:
		1) If size fails, False, and a tuple containing a message, the given size, and the actual size
		2) If there is an os error, False, and a tuple containing the system error followed by 2 nulls
		3) If a checksum fails, False and a tuple containing a message, the given hash, and the actual hash
		4) If all checks succeed, return True and a fake reason
	"""
    # Dict relates to single file only.
    # returns: (passed,reason)
    file_is_ok = True
    reason = "Reason unknown"
    try:
        mysize = os.stat(filename)[stat.ST_SIZE]
        if mydict["size"] != mysize:
            return False, (_("Filesize does not match recorded size"), mysize, mydict["size"])
    except OSError as e:
        if e.errno == errno.ENOENT:
            raise portage.exception.FileNotFound(filename)
        return False, (str(e), None, None)

    verifiable_hash_types = set(mydict).intersection(hashfunc_map)
    verifiable_hash_types.discard("size")
    if not verifiable_hash_types:
        expected = set(hashfunc_map)
        expected.discard("size")
        expected = list(expected)
        expected.sort()
        expected = " ".join(expected)
        got = set(mydict)
        got.discard("size")
        got = list(got)
        got.sort()
        got = " ".join(got)
        return False, (_("Insufficient data for checksum verification"), got, expected)

    for x in sorted(mydict):
        if x == "size":
            continue
        elif x in hashfunc_map:
            myhash = perform_checksum(filename, x, calc_prelink=calc_prelink)[0]
            if mydict[x] != myhash:
                if strict:
                    raise portage.exception.DigestException(
                        ("Failed to verify '$(file)s' on " + "checksum type '%(type)s'") % {"file": filename, "type": x}
                    )
                else:
                    file_is_ok = False
                    reason = (("Failed on %s verification" % x), myhash, mydict[x])
                    break
    return file_is_ok, reason

def _ensure_log_subdirs(logdir, subdir):
	"""
	This assumes that logdir exists, and creates subdirectories down
	to subdir as necessary. The gid of logdir is copied to all
	subdirectories, along with 0x2070 mode bits if present. Both logdir
	and subdir are assumed to be normalized absolute paths.
	"""
	st = os.stat(logdir)
	uid = -1
	gid = st.st_gid
	grp_mode = 0o2070 & st.st_mode

	# If logdir is writable by the portage group but its uid
	# is not portage_uid, then set the uid to portage_uid if
	# we have privileges to do so, for compatibility with our
	# default logrotate config (see bug 378451). With the
	# "su portage portage" directive and logrotate-3.8.0,
	# logrotate's chown call during the compression phase will
	# only succeed if the log file's uid is portage_uid.
	if grp_mode and gid == portage_gid and \
		portage.data.secpass >= 2:
		uid = portage_uid
		if st.st_uid != portage_uid:
			ensure_dirs(logdir, uid=uid)

	logdir_split_len = len(logdir.split(os.sep))
	subdir_split = subdir.split(os.sep)[logdir_split_len:]
	subdir_split.reverse()
	current = logdir
	while subdir_split:
		current = os.path.join(current, subdir_split.pop())
		ensure_dirs(current, uid=uid, gid=gid, mode=grp_mode, mask=0)

	def _migrate(self, update_location):
		"""
		When repo.user_location is a normal directory, migrate it to
		storage so that it can be replaced with a symlink. After migration,
		commit the content as the latest snapshot.
		"""
		try:
			os.rename(self._user_location, update_location)
		except OSError:
			portage.util.ensure_dirs(update_location)
			portage.util.apply_stat_permissions(update_location,
				os.stat(self._user_location))
			# It's probably on a different device, so copy it.
			yield self._check_call(['rsync', '-a',
				self._user_location + '/', update_location + '/'])

			# Remove the old copy so that symlink can be created. Run with
			# maximum privileges, since removal requires write access to
			# the parent directory.
			yield self._check_call(['rm', '-rf', user_location], privileged=True)

		self._update_location = update_location

		# Make this copy the latest snapshot
		yield self.commit_update()

def RecursiveFileLoader(filename):
    """
	If filename is of type file, return a generate that yields filename
	else if filename is of type directory, return a generator that fields
	files in that directory.
	
	Ignore files beginning with . or ending in ~.
	Prune CVS directories.

	@param filename: name of a file/directory to traverse
	@rtype: list
	@returns: List of files to process
	"""

    try:
        st = os.stat(filename)
    except OSError:
        return
    if stat.S_ISDIR(st.st_mode):
        for root, dirs, files in os.walk(filename):
            for d in list(dirs):
                if d[:1] == "." or d == "CVS":
                    dirs.remove(d)
            for f in files:
                try:
                    f = _unicode_decode(f, encoding=_encodings["fs"], errors="strict")
                except UnicodeDecodeError:
                    continue
                if f[:1] == "." or f[-1:] == "~":
                    continue
                yield os.path.join(root, f)
    else:
        yield filename

def have_ebuild_dir(path, maxdepth=3):
	""" 
	Try to figure out if 'path' or a subdirectory contains one or more
	ebuild files named appropriately for their parent directory.
	"""
	stack = [(normalize_path(path), 1)]
	while stack:
		path, depth = stack.pop()
		basename = os.path.basename(path)
		try:
			listdir = os.listdir(path)
		except OSError:
			continue
		for filename in listdir:
			abs_filename = os.path.join(path, filename)
			try:
				st = os.stat(abs_filename)
			except OSError:
				continue
			if stat.S_ISDIR(st.st_mode):
				if depth < maxdepth:
					stack.append((abs_filename, depth + 1))
			elif stat.S_ISREG(st.st_mode):
				if filename.endswith(".ebuild") and \
					filename.startswith(basename + "-"):
					return os.path.dirname(os.path.dirname(path))

	def _pkgindex_entry(self, cpv):
		"""
		Performs checksums and evaluates USE flag conditionals.
		Raises InvalidDependString if necessary.
		@rtype: dict
		@return: a dict containing entry for the give cpv.
		"""

		pkg_path = self.getname(cpv)

		d = dict(zip(self._pkgindex_aux_keys,
			self.dbapi.aux_get(cpv, self._pkgindex_aux_keys)))

		d.update(perform_multiple_checksums(
			pkg_path, hashes=self._pkgindex_hashes))

		d["CPV"] = cpv
		st = os.stat(pkg_path)
		d["MTIME"] = str(st[stat.ST_MTIME])
		d["SIZE"] = str(st.st_size)

		rel_path = self._pkg_paths[cpv]
		# record location if it's non-default
		if rel_path != cpv + ".tbz2":
			d["PATH"] = rel_path

		self._eval_use_flags(cpv, d)
		return d

	def load(self):
		atoms_changed = False
		try:
			mtime = os.stat(self._filename).st_mtime
		except (OSError, IOError):
			mtime = None
		if (not self._loaded or self._mtime != mtime):
			try:
				data, errors = self.loader.load()
				for fname in errors:
					for e in errors[fname]:
						self.errors.append(fname+": "+e)
			except EnvironmentError as e:
				if e.errno != errno.ENOENT:
					raise
				del e
				data = {}
			nonatoms = list(data)
			self._mtime = mtime
			atoms_changed = True
		else:
			nonatoms = list(self._nonatoms)

		if atoms_changed:
			self._setAtoms(nonatoms)