revdep_rebuild/assign.py: handle directory symlinks (bug 611808)

Use a _file_matcher class to make file comparisons work regardless
of directory symlinks.

X-Gentoo-bug: 611808
X-Gentoo-bug-url: https://bugs.gentoo.org/show_bug.cgi?id=611808
Acked-by: Brian Dolbec <dolsen@gentoo.org>

1 files changed, 60 insertions, 7 deletions

diff --git a/pym/gentoolkit/revdep_rebuild/assign.py b/pym/gentoolkit/revdep_rebuild/assign.py
index 00dda6e..84bd59f 100644
--- a/pym/gentoolkit/revdep_rebuild/assign.py
+++ b/pym/gentoolkit/revdep_rebuild/assign.py
@@ -6,6 +6,7 @@ Functions used for determining the package the broken lib belongs to.
 
 from __future__ import print_function
 
+import errno
 import os
 import io
 import re
@@ -22,11 +23,61 @@ try:
 except NameError:
 	pass
 
+
+class _file_matcher(object):
+	"""
+	Compares files by basename and parent directory (device, inode),
+	so comparisons work regardless of directory symlinks. If a
+	parent directory does not exist, the realpath of the parent
+	directory is used instead of the (device, inode). When multiple
+	files share the same parent directory, stat is only called
+	once per directory, and the result is cached internally.
+	"""
+	def __init__(self):
+		self._file_ids = {}
+		self._added = {}
+
+	def _file_id(self, filename):
+		try:
+			return self._file_ids[filename]
+		except KeyError:
+			try:
+				st = os.stat(filename)
+			except OSError as e:
+				if e.errno != errno.ENOENT:
+					raise
+				file_id = (os.path.realpath(filename),)
+			else:
+				file_id = (st.st_dev, st.st_ino)
+
+			self._file_ids[filename] = file_id
+			return file_id
+
+	def _file_key(self, filename):
+		head, tail = os.path.split(filename)
+		key = self._file_id(head) + (tail,)
+		return key
+
+	def add(self, filename):
+		self._added[self._file_key(filename)] = filename
+
+	def intersection(self, other):
+		for file_key in self._added:
+			match = other._added.get(file_key)
+			if match is not None:
+				yield match
+
+
 def assign_packages(broken, logger, settings):
 	''' Finds and returns packages that owns files placed in broken.
 		Broken is list of files
 	'''
 	stime = current_milli_time()
+
+	broken_matcher = _file_matcher()
+	for filename in broken:
+		broken_matcher.add(filename)
+
 	assigned_pkgs = set()
 	assigned_filenames = set()
 	for group in os.listdir(settings['PKG_DIR']):
@@ -39,21 +90,23 @@ def assign_packages(broken, logger, settings):
 				continue
 			f = pkgpath + '/CONTENTS'
 			if os.path.exists(f):
+				contents_matcher = _file_matcher()
 				try:
 					with io.open(f, 'r', encoding='utf_8') as cnt:
 						for line in cnt.readlines():
 							m = re.match('^obj (/[^ ]+)', line)
 							if m is not None:
-								m = m.group(1)
-								if m in broken:
-									found = group+'/'+pkg
-									assigned_pkgs.add(found)
-									assigned_filenames.add(m)
-									logger.info('\t' + green('* ') + m +
-												' -> ' + bold(found))
+								contents_matcher.add(m.group(1))
 				except Exception as e:
 					logger.warning(red(' !! Failed to read ' + f))
 					logger.warning(red(' !! Error was:' + str(e)))
+				else:
+					for m in contents_matcher.intersection(broken_matcher):
+						found = group+'/'+pkg
+						assigned_pkgs.add(found)
+						assigned_filenames.add(m)
+						logger.info('\t' + green('* ') + m +
+									' -> ' + bold(found))
 
 	broken_filenames = set(broken)
 	orphaned = broken_filenames.difference(assigned_filenames)