portdbapi: fix volatile cache handling

The metadata_overlay usage, that was triggered automatically for users
without depcachedir write access, has been broken since commit
2ed1cb53cc4158af08c22d466b15b9a9a7767212. The metadata_overlay class
is not compatible with the new validation code, so remove it. If users
have metadata_overlay configured as their cache module, fall back to
flat_hash.

4 files changed, 20 insertions, 120 deletions

diff --git a/pym/portage/cache/metadata_overlay.py b/pym/portage/cache/metadata_overlay.py
deleted file mode 100644
index cfa0051e6..000000000
--- a/pym/portage/cache/metadata_overlay.py
+++ /dev/null
@@ -1,105 +0,0 @@
-# Copyright 1999-2010 Gentoo Foundation
-# Distributed under the terms of the GNU General Public License v2
-
-from portage.cache import template
-from portage.cache.cache_errors import CacheCorruption
-from portage.cache.flat_hash import database as db_rw
-from portage.cache.metadata import database as db_ro
-
-class database(template.database):
-
-	serialize_eclasses = False
-
-	def __init__(self, location, label, auxdbkeys, db_rw=db_rw, db_ro=db_ro,
-		*args, **config):
-		super_config = config.copy()
-		super_config.pop("gid", None)
-		super_config.pop("perms", None)
-		super(database, self).__init__(location, label, auxdbkeys,
-			*args, **super_config)
-		self.db_rw = db_rw(location, label, auxdbkeys, **config)
-		self.commit = self.db_rw.commit
-		self.autocommits = self.db_rw.autocommits
-		if isinstance(db_ro, type):
-			ro_config = config.copy()
-			ro_config["readonly"] = True
-			self.db_ro = db_ro(label, "metadata/cache", auxdbkeys, **ro_config)
-		else:
-			self.db_ro = db_ro
-
-	def __getitem__(self, cpv):
-		"""funnel whiteout validation through here, since value needs to be fetched"""
-		try:
-			value = self.db_rw[cpv]
-		except KeyError:
-			return self.db_ro[cpv] # raises a KeyError when necessary
-		except CacheCorruption:
-			del self.db_rw[cpv]
-			return self.db_ro[cpv] # raises a KeyError when necessary
-		if self._is_whiteout(value):
-			if self._is_whiteout_valid(cpv, value):
-				raise KeyError(cpv)
-			else:
-				del self.db_rw[cpv]
-				return self.db_ro[cpv] # raises a KeyError when necessary
-		else:
-			return value
-
-	def _setitem(self, name, values):
-		try:
-			value_ro = self.db_ro.get(name)
-		except CacheCorruption:
-			value_ro = None
-		if value_ro is not None and \
-			self._are_values_identical(value_ro, values):
-			# we have matching values in the underlying db_ro
-			# so it is unnecessary to store data in db_rw
-			try:
-				del self.db_rw[name] # delete unwanted whiteout when necessary
-			except KeyError:
-				pass
-			return
-		self.db_rw[name] = values
-
-	def _delitem(self, cpv):
-		value = self[cpv] # validates whiteout and/or raises a KeyError when necessary
-		if cpv in self.db_ro:
-			self.db_rw[cpv] = self._create_whiteout(value)
-		else:
-			del self.db_rw[cpv]
-
-	def __contains__(self, cpv):
-		try:
-			self[cpv] # validates whiteout when necessary
-		except KeyError:
-			return False
-		return True
-
-	def __iter__(self):
-		s = set()
-		for cpv in self.db_rw:
-			if cpv in self: # validates whiteout when necessary
-				yield cpv
-			# set includes whiteouts so they won't be yielded later
-			s.add(cpv)
-		for cpv in self.db_ro:
-			if cpv not in s:
-				yield cpv
-
-	def _is_whiteout(self, value):
-		return value["EAPI"] == "whiteout"
-
-	def _create_whiteout(self, value):
-		return {"EAPI":"whiteout","_eclasses_":value["_eclasses_"],"_mtime_":value["_mtime_"]}
-
-	def _is_whiteout_valid(self, name, value_rw):
-		try:
-			value_ro = self.db_ro[name]
-			return self._are_values_identical(value_rw,value_ro)
-		except KeyError:
-			return False
-
-	def _are_values_identical(self, value1, value2):
-		if value1['_mtime_'] != value2['_mtime_']:
-			return False
-		return value1["_eclasses_"] == value2["_eclasses_"]
diff --git a/pym/portage/cache/volatile.py b/pym/portage/cache/volatile.py
index 18049dddb..a3c57f55f 100644
--- a/pym/portage/cache/volatile.py
+++ b/pym/portage/cache/volatile.py
@@ -8,6 +8,7 @@ class database(template.database):
 
 	autocommits = True
 	serialize_eclasses = False
+	store_eclass_paths = False
 
 	def __init__(self, *args, **config):
 		config.pop("gid", None)
@@ -16,10 +17,10 @@ class database(template.database):
 		self._data = {}
 		self._delitem = self._data.__delitem__
 
-	def _setitem(self, name, values):
+	def __setitem__(self, name, values):
 		self._data[name] = copy.deepcopy(values)
 
-	def _getitem(self, cpv):
+	def __getitem__(self, cpv):
 		return copy.deepcopy(self._data[cpv])
 
 	def __iter__(self):
diff --git a/pym/portage/dbapi/porttree.py b/pym/portage/dbapi/porttree.py
index 6ad7a6b37..aad72e144 100644
--- a/pym/portage/dbapi/porttree.py
+++ b/pym/portage/dbapi/porttree.py
@@ -17,7 +17,7 @@ portage.proxy.lazyimport.lazyimport(globals(),
 	'portage.versions:best,catpkgsplit,_pkgsplit@pkgsplit,ver_regexp',
 )
 
-from portage.cache import metadata_overlay, volatile
+from portage.cache import volatile
 from portage.cache.cache_errors import CacheError
 from portage.cache.mappings import Mapping
 from portage.dbapi import dbapi
@@ -150,6 +150,9 @@ class portdbapi(dbapi):
 		self.auxdbmodule = self.settings.load_best_module("portdbapi.auxdbmodule")
 		self.auxdb = {}
 		self._pregen_auxdb = {}
+		# If the current user doesn't have depcachedir write permission,
+		# then the depcachedir cache is kept here read-only access.
+		self._ro_auxdb = {}
 		self._init_cache_dirs()
 		try:
 			depcachedir_st = os.stat(self.depcachedir)
@@ -189,18 +192,14 @@ class portdbapi(dbapi):
 		# to the cache entries/directories.
 		if (secpass < 1 and not depcachedir_unshared) or not depcachedir_w_ok:
 			for x in self.porttrees:
+				self.auxdb[x] = volatile.database(
+					self.depcachedir, x, filtered_auxdbkeys,
+					**cache_kwargs)
 				try:
-					db_ro = self.auxdbmodule(self.depcachedir, x,
+					self._ro_auxdb[x] = self.auxdbmodule(self.depcachedir, x,
 						filtered_auxdbkeys, readonly=True, **cache_kwargs)
 				except CacheError:
-					self.auxdb[x] = volatile.database(
-						self.depcachedir, x, filtered_auxdbkeys,
-						**cache_kwargs)
-				else:
-					self.auxdb[x] = metadata_overlay.database(
-						self.depcachedir, x, filtered_auxdbkeys,
-						db_rw=volatile.database, db_ro=db_ro,
-						**cache_kwargs)
+					pass
 		else:
 			for x in self.porttrees:
 				if x in self.auxdb:
@@ -208,8 +207,6 @@ class portdbapi(dbapi):
 				# location, label, auxdbkeys
 				self.auxdb[x] = self.auxdbmodule(
 					self.depcachedir, x, filtered_auxdbkeys, **cache_kwargs)
-				if self.auxdbmodule is metadata_overlay.database:
-					self.auxdb[x].db_ro.ec = self._repo_info[x].eclass_db
 		if "metadata-transfer" not in self.settings.features:
 			for x in self.porttrees:
 				if x in self._pregen_auxdb:
@@ -440,6 +437,9 @@ class portdbapi(dbapi):
 		pregen_auxdb = self._pregen_auxdb.get(repo_path)
 		if pregen_auxdb is not None:
 			auxdbs.append(pregen_auxdb)
+		ro_auxdb = self._ro_auxdb.get(repo_path)
+		if ro_auxdb is not None:
+			auxdbs.append(ro_auxdb)
 		auxdbs.append(self.auxdb[repo_path])
 		eclass_db = self._repo_info[repo_path].eclass_db
 
diff --git a/pym/portage/package/ebuild/config.py b/pym/portage/package/ebuild/config.py
index a80c82dd5..2739584c5 100644
--- a/pym/portage/package/ebuild/config.py
+++ b/pym/portage/package/ebuild/config.py
@@ -887,7 +887,11 @@ class config(object):
 				try:
 					mod = load_mod(best_mod)
 				except ImportError:
-					raise
+					if best_mod == "portage.cache.metadata_overlay.database":
+						best_mod = "portage.cache.flat_hash.database"
+						mod = load_mod(best_mod)
+					else:
+						raise
 		return mod
 
 	def lock(self):