cache: rewrite to support arbitrary validation method

Specifically, the cache can use any portage supported checksum method,
or use the standard mtime approach.  In addition, support controlling
whether or not paths are stored, and generally try to restore some
of the centralization/encapsulation that was in place originally.
(cherry picked from commit bc1aed614fb588f0ade5bcb5d1265a8db0f8d247)

Change-Id: Ic38057e7dbb15063c64a93c99e66e113a7d4c70e

3 files changed, 19 insertions, 18 deletions

diff --git a/pym/_emerge/EbuildMetadataPhase.py b/pym/_emerge/EbuildMetadataPhase.py
index e53298bae..aeff2f0e8 100644
--- a/pym/_emerge/EbuildMetadataPhase.py
+++ b/pym/_emerge/EbuildMetadataPhase.py
@@ -20,8 +20,8 @@ class EbuildMetadataPhase(SubProcess):
 	used to extract metadata from the ebuild.
 	"""
 
-	__slots__ = ("cpv", "ebuild_path", "fd_pipes", "metadata_callback",
-		"ebuild_mtime", "metadata", "portdb", "repo_path", "settings") + \
+	__slots__ = ("cpv", "ebuild_hash", "fd_pipes", "metadata_callback",
+		"metadata", "portdb", "repo_path", "settings") + \
 		("_raw_metadata",)
 
 	_file_names = ("ebuild",)
@@ -31,7 +31,7 @@ class EbuildMetadataPhase(SubProcess):
 	def _start(self):
 		settings = self.settings
 		settings.setcpv(self.cpv)
-		ebuild_path = self.ebuild_path
+		ebuild_path = self.ebuild_hash.location
 
 		eapi = None
 		if eapi is None and \
@@ -44,8 +44,8 @@ class EbuildMetadataPhase(SubProcess):
 
 		if eapi is not None:
 			if not portage.eapi_is_supported(eapi):
-				self.metadata_callback(self.cpv, self.ebuild_path,
-					self.repo_path, {'EAPI' : eapi}, self.ebuild_mtime)
+				self.metadata_callback(self.cpv, ebuild_path,
+					self.repo_path, {'EAPI' : eapi}, self.ebuild_hash.mtime)
 				self._set_returncode((self.pid, os.EX_OK << 8))
 				self.wait()
 				return
@@ -128,6 +128,5 @@ class EbuildMetadataPhase(SubProcess):
 			else:
 				metadata = zip(portage.auxdbkeys, metadata_lines)
 				self.metadata = self.metadata_callback(self.cpv,
-					self.ebuild_path, self.repo_path, metadata,
-					self.ebuild_mtime)
+					self.repo_path, metadata, self.ebuild_hash)
 
diff --git a/pym/_emerge/MetadataRegen.py b/pym/_emerge/MetadataRegen.py
index 810317533..b3380562b 100644
--- a/pym/_emerge/MetadataRegen.py
+++ b/pym/_emerge/MetadataRegen.py
@@ -3,6 +3,7 @@
 
 import portage
 from portage import os
+from portage.eclass_cache import hashed_path
 from _emerge.EbuildMetadataPhase import EbuildMetadataPhase
 from _emerge.PollScheduler import PollScheduler
 
@@ -68,16 +69,15 @@ class MetadataRegen(PollScheduler):
 				ebuild_path, repo_path = portdb.findname2(cpv)
 				if ebuild_path is None:
 					raise AssertionError("ebuild not found for '%s'" % cpv)
-				metadata, st, emtime = portdb._pull_valid_cache(
+				metadata, ebuild_hash = portdb._pull_valid_cache(
 					cpv, ebuild_path, repo_path)
 				if metadata is not None:
 					if consumer is not None:
-						consumer(cpv, ebuild_path,
-							repo_path, metadata)
+						consumer(cpv, repo_path, metadata, ebuild_hash)
 					continue
 
-				yield EbuildMetadataPhase(cpv=cpv, ebuild_path=ebuild_path,
-					ebuild_mtime=emtime,
+				yield EbuildMetadataPhase(cpv=cpv,
+					ebuild_hash=ebuild_hash,
 					metadata_callback=portdb._metadata_callback,
 					portdb=portdb, repo_path=repo_path,
 					settings=portdb.doebuild_settings)
@@ -176,9 +176,9 @@ class MetadataRegen(PollScheduler):
 			# On failure, still notify the consumer (in this case the metadata
 			# argument is None).
 			self._consumer(metadata_process.cpv,
-				metadata_process.ebuild_path,
 				metadata_process.repo_path,
-				metadata_process.metadata)
+				metadata_process.metadata,
+				metadata_process.ebuild_hash)
 
 		self._schedule()
 
diff --git a/pym/_emerge/actions.py b/pym/_emerge/actions.py
index 844cf28ed..c449b5874 100644
--- a/pym/_emerge/actions.py
+++ b/pym/_emerge/actions.py
@@ -1737,8 +1737,9 @@ def action_metadata(settings, portdb, myopts, porttrees=None):
 
 				if dest is not None:
 					if not (dest['_mtime_'] == src['_mtime_'] and \
-						tree_data.eclass_db.is_eclass_data_valid(
-							dest['_eclasses_']) and \
+						tree_data.eclass_db.validate_and_rewrite_cache(
+							dest['_eclasses_'], tree_data.dest_db.validation_chf,
+							tree_data.dest_db.store_eclass_paths) and \
 						set(dest['_eclasses_']) == set(src['_eclasses_'])):
 						dest = None
 					else:
@@ -1763,8 +1764,9 @@ def action_metadata(settings, portdb, myopts, porttrees=None):
 					continue
 
 				if eclasses is not None:
-					if not tree_data.eclass_db.is_eclass_data_valid(
-						src['_eclasses_']):
+					if not tree_data.eclass_db.validate_and_rewrite_cache(
+						src['_eclasses_'], tree_data.src_db.validation_chf,
+						tree_data.src_db.store_eclass_paths):
 						continue
 					inherited = eclasses
 				else: