How to use the portage.os.path.dirname function in portage

pkgindex = None
			if proc is not None:
				if proc.poll() is None:
					proc.kill()
					proc.wait()
				proc = None
			if tmp_filename is not None:
				try:
					os.unlink(tmp_filename)
				except OSError:
					pass
			if pkgindex is rmt_idx:
				pkgindex.modified = False # don't update the header
				pkgindex.header["DOWNLOAD_TIMESTAMP"] = "%d" % time.time()
				try:
					ensure_dirs(os.path.dirname(pkgindex_file))
					f = atomic_ofstream(pkgindex_file)
					pkgindex.write(f)
					f.close()
				except (IOError, PortageException):
					if os.access(os.path.dirname(pkgindex_file), os.W_OK):
						raise
					# The current user doesn't have permission to cache the
					# file, but that's alright.
			if pkgindex:
				remote_base_uri = pkgindex.header.get("URI", base_url)
				for d in pkgindex.packages:
					cpv = _pkg_str(d["CPV"], metadata=d,
						settings=self.settings, db=self.dbapi)
					# Local package instances override remote instances
					# with the same instance_key.
					if self.dbapi.cpv_exists(cpv):

mydata = myid[1]
	myindexlen = len(myindex)
	startpos = 0
	while ((startpos + 8) < myindexlen):
		namelen = decodeint(myindex[startpos:startpos + 4])
		datapos = decodeint(myindex[startpos + 4 + namelen:startpos + 8 + namelen])
		datalen = decodeint(myindex[startpos + 8 + namelen:startpos + 12 + namelen])
		myname = myindex[startpos + 4:startpos + 4 + namelen]
		myname = _unicode_decode(myname,
			encoding=_encodings['repo.content'], errors='replace')
		filename = os.path.join(mydest, myname.lstrip(os.sep))
		filename = normalize_path(filename)
		if not filename.startswith(mydest):
			# myname contains invalid ../ component(s)
			continue
		dirname = os.path.dirname(filename)
		if dirname:
			if not os.path.exists(dirname):
				os.makedirs(dirname)
		mydat = open(_unicode_encode(filename,
			encoding=_encodings['fs'], errors='strict'), 'wb')
		mydat.write(mydata[datapos:datapos + datalen])
		mydat.close()
		startpos = startpos + namelen + 12

if cfgprot:
								mydest = new_protect_filename(mydest, newmd5=mymd5)

				# whether config protection or not, we merge the new file the
				# same way.  Unless moveme=0 (blocking directory)
				if moveme:
					# Do not hardlink files unless they are in the same
					# directory, since otherwise tar may not be able to
					# extract a tarball of the resulting hardlinks due to
					# 'Invalid cross-device link' errors (depends on layout of
					# mount points). Also, don't hardlink zero-byte files since
					# it doesn't save any space, and don't hardlink
					# CONFIG_PROTECTed files since config files shouldn't be
					# hardlinked to eachother (for example, shadow installs
					# several identical config files inside /etc/pam.d/).
					parent_dir = os.path.dirname(myrealdest)
					hardlink_key = (parent_dir, mymd5, mystat.st_size,
						mystat.st_mode, mystat.st_uid, mystat.st_gid)

					hardlink_candidates = None
					if not protected and mystat.st_size != 0:
						hardlink_candidates = self._md5_merge_map.get(hardlink_key)
						if hardlink_candidates is None:
							hardlink_candidates = []
							self._md5_merge_map[hardlink_key] = hardlink_candidates

					mymtime = movefile(mysrc, mydest, newmtime=thismtime,
						sstat=mystat, mysettings=self.settings,
						hardlink_candidates=hardlink_candidates,
						encoding=_encodings['merge'])
					if mymtime is None:
						return 1

proc = None
			if tmp_filename is not None:
				try:
					os.unlink(tmp_filename)
				except OSError:
					pass
			if pkgindex is rmt_idx:
				pkgindex.modified = False # don't update the header
				pkgindex.header["DOWNLOAD_TIMESTAMP"] = "%d" % time.time()
				try:
					ensure_dirs(os.path.dirname(pkgindex_file))
					f = atomic_ofstream(pkgindex_file)
					pkgindex.write(f)
					f.close()
				except (IOError, PortageException):
					if os.access(os.path.dirname(pkgindex_file), os.W_OK):
						raise
					# The current user doesn't have permission to cache the
					# file, but that's alright.
			if pkgindex:
				remote_base_uri = pkgindex.header.get("URI", base_url)
				for d in pkgindex.packages:
					cpv = _pkg_str(d["CPV"], metadata=d,
						settings=self.settings, db=self.dbapi)
					# Local package instances override remote instances
					# with the same instance_key.
					if self.dbapi.cpv_exists(cpv):
						continue

					d["CPV"] = cpv
					d["BASE_URI"] = remote_base_uri
					d["PKGINDEX_URI"] = url

def read_ld_so_conf(path):
		for l in grabfile(path):
			include_match = _ld_so_include_re.match(l)
			if include_match is not None:
				subpath = os.path.join(os.path.dirname(path),
					include_match.group(1))
				for p in glob.glob(subpath):
					for r in read_ld_so_conf(p):
						yield r
			else:
				yield l

dest_path = normalize_path(
					os.path.join(destroot, f.lstrip(os.path.sep)))
				try:
					dest_lstat = os.lstat(dest_path)
				except EnvironmentError as e:
					if e.errno == errno.ENOENT:
						del e
						continue
					elif e.errno == errno.ENOTDIR:
						del e
						# A non-directory is in a location where this package
						# expects to have a directory.
						dest_lstat = None
						parent_path = dest_path
						while len(parent_path) > len(destroot):
							parent_path = os.path.dirname(parent_path)
							try:
								dest_lstat = os.lstat(parent_path)
								break
							except EnvironmentError as e:
								if e.errno != errno.ENOTDIR:
									raise
								del e
						if not dest_lstat:
							raise AssertionError(
								"unable to find non-directory " + \
								"parent for '%s'" % dest_path)
						dest_path = parent_path
						f = os.path.sep + dest_path[len(destroot):]
						if f in collisions:
							continue
					else:

import portage
from portage import normalize_path
from portage import os
from portage.output import green
from portage.util.futures.extendedfutures import ExtendedFuture
from repoman.metadata import get_metadata_xsd
from repoman.modules.commit import repochecks
from repoman.modules.commit import manifest
from repoman.profile import check_profiles, dev_profile_keywords, setup_profile
from repoman.repos import repo_metadata
from repoman.modules.scan.scan import scan
from repoman.modules.vcs.vcs import vcs_files_to_cps

from portage.module import Modules

MODULES_PATH = os.path.join(os.path.dirname(__file__), "modules", "scan")
# initial development debug info
logging.debug("module path: %s", MODULES_PATH)

MODULE_CONTROLLER = Modules(path=MODULES_PATH, namepath="repoman.modules.scan")

MODULE_NAMES = MODULE_CONTROLLER.module_names[:]
# initial development debug info
logging.debug("module_names: %s", MODULE_NAMES)

DATA_TYPES = {'dict': dict, 'Future': ExtendedFuture, 'list': list, 'set': set}


class Scanner(object):
	'''Primary scan class.  Operates all the small Q/A tests and checks'''

	def __init__(self, repo_settings, myreporoot, config_root, options,

def digests(self, checkdir):
		'''Returns the freshly loaded digests

		@param checkdir: string, directory path
		'''
		mf = self.repoman_settings.repositories.get_repo_for_location(
			os.path.dirname(os.path.dirname(checkdir)))
		mf = mf.load_manifest(checkdir, self.repoman_settings["DISTDIR"])
		_digests = mf.getTypeDigests("DIST")
		del mf
		return _digests

# This will probably never happen, but it might if one of the
				# paths returned from findConsumers() refers to one of the libs
				# that should be preserved yet the path is not listed in the
				# contents. Such a path might belong to some other package, so
				# it shouldn't be preserved here.
				showMessage(_("!!! File '%s' will not be preserved "
					"due to missing contents entry\n") % (f_abs,),
					level=logging.ERROR, noiselevel=-1)
				preserve_paths.remove(f)
				continue
			new_contents[f_abs] = contents_entry
			obj_type = contents_entry[0]
			showMessage(_(">>> needed    %s %s\n") % (obj_type, f_abs),
				noiselevel=-1)
			# Add parent directories to contents if necessary.
			parent_dir = os.path.dirname(f_abs)
			while len(parent_dir) > len(root):
				new_contents[parent_dir] = ["dir"]
				prev = parent_dir
				parent_dir = os.path.dirname(parent_dir)
				if prev == parent_dir:
					break
		outfile = atomic_ofstream(os.path.join(self.dbtmpdir, "CONTENTS"))
		write_contents(new_contents, root, outfile)
		outfile.close()
		self._clear_contents_cache()

def counter_tick_core(self, myroot=None, incrementing=1, mycpv=None):
		"""
		This method will grab the next COUNTER value and record it back
		to the global file.  Returns new counter value.

		@param myroot: ignored, self._eroot is used instead
		"""
		myroot = None
		counter = self.get_counter_tick_core(mycpv=mycpv) - 1
		if incrementing:
			#increment counter
			counter += 1
			# use same permissions as config._init_dirs()
			ensure_dirs(os.path.dirname(self._counter_path),
				gid=portage_gid, mode=0o2750, mask=0o2)
			# update new global counter file
			write_atomic(self._counter_path, str(counter))
		return counter