GLEP 59: use manifest-hashes list in layout.conf

The manifest-hashes layout.conf setting simply overrides the hashes
that are generated. When unspecified, the MANIFEST2_HASH_DEFAULTS
constant is used instead (current value contains SHA1, SHA256, and
RMD160).

In order to enable SHA512 and WHIRLPOOL, and drop RMD160 and SHA1,
simply set "manifest-hashes = SHA256 SHA512 WHIRLPOOL" in layout.conf.
As with the previous boolean flags approach, manifest-hashes settings
become redundant and can be removed from layout.conf after a version
of portage with equivalent defaults is stable.

3 files changed, 19 insertions, 31 deletions

diff --git a/pym/portage/const.py b/pym/portage/const.py
index e7eac62fb..e3627ea6e 100644
--- a/pym/portage/const.py
+++ b/pym/portage/const.py
@@ -114,20 +114,23 @@ MANIFEST1_REQUIRED_HASH  = "MD5"
 # Future events:
 #
 # After WHIRLPOOL is supported in stable portage:
-# - Add WHIRLPOOL to MANIFEST2_HASH_DEFAULTS.
+# - Add SHA256 and WHIRLPOOL to MANIFEST2_HASH_DEFAULTS.
 # - Remove SHA1 and RMD160 from MANIFEST2_HASH_*.
-# - Toggle gentoo-x86/metadata/layout.conf settings to match.
+# - Set manifest-hashes in gentoo-x86/metadata/layout.conf as follows:
+#     manifest-hashes = SHA256 SHA512 WHIRLPOOL
 #
 # After WHIRLPOOL is supported in stable portage for at least 1 year:
 # - Change MANIFEST2_REQUIRED_HASH to WHIRLPOOL.
 # - Remove SHA256 from MANIFEST2_HASH_*.
-# - Toggle gentoo-x86/metadata/layout.conf settings to match.
+# - Set manifest-hashes in gentoo-x86/metadata/layout.conf as follows:
+#     manifest-hashes = SHA512 WHIRLPOOL
 #
 # After SHA-3 is approved:
 # - Add new hashes to MANIFEST2_HASH_*.
 #
 # After SHA-3 is supported in stable portage:
-# - Toggle gentoo-x86/metadata/layout.conf settings to match.
+# - Set manifest-hashes in gentoo-x86/metadata/layout.conf as follows:
+#     manifest-hashes = SHA3 SHA512 WHIRLPOOL
 #
 # After layout.conf settings correspond to defaults in stable portage:
 # - Remove redundant settings from gentoo-x86/metadata/layout.conf.
diff --git a/pym/portage/manifest.py b/pym/portage/manifest.py
index eaea0bdf6..78153c02a 100644
--- a/pym/portage/manifest.py
+++ b/pym/portage/manifest.py
@@ -103,7 +103,7 @@ class Manifest(object):
 	parsers = (parseManifest2,)
 	def __init__(self, pkgdir, distdir, fetchlist_dict=None,
 		manifest1_compat=DeprecationWarning, from_scratch=False, thin=False,
-			allow_missing=False, allow_create=True, hash_flags=None):
+			allow_missing=False, allow_create=True, hashes=None):
 		""" Create new Manifest instance for package in pkgdir.
 		    Do not parse Manifest file if from_scratch == True (only for internal use)
 			The fetchlist_dict parameter is required only for generation of
@@ -120,14 +120,10 @@ class Manifest(object):
 		self.fhashdict = {}
 		self.hashes = set()
 
-		if hash_flags is None:
-			hash_flags = {}
-		self.hash_flags = hash_flags
-		for hash_type in MANIFEST2_HASH_FUNCTIONS:
-			default_state = hash_type in MANIFEST2_HASH_DEFAULTS
-			if hash_flags.get(hash_type, default_state):
-				self.hashes.add(hash_type)
+		if hashes is None:
+			hashes = MANIFEST2_HASH_DEFAULTS
 
+		self.hashes.update(hashes.intersection(MANIFEST2_HASH_FUNCTIONS))
 		self.hashes.difference_update(hashname for hashname in \
 			list(self.hashes) if hashname not in hashfunc_map)
 		self.hashes.add("size")
@@ -360,7 +356,7 @@ class Manifest(object):
 		self.__init__(self.pkgdir, self.distdir,
 			fetchlist_dict=self.fetchlist_dict, from_scratch=True,
 			thin=self.thin, allow_missing=self.allow_missing,
-			allow_create=self.allow_create, hash_flags=self.hash_flags)
+			allow_create=self.allow_create, hashes=self.hashes)
 		pn = os.path.basename(self.pkgdir.rstrip(os.path.sep))
 		cat = self._pkgdir_category()
 
diff --git a/pym/portage/repository/config.py b/pym/portage/repository/config.py
index c201fe751..779d432be 100644
--- a/pym/portage/repository/config.py
+++ b/pym/portage/repository/config.py
@@ -44,7 +44,7 @@ class RepoConfig(object):
 	__slots__ = ['aliases', 'eclass_overrides', 'eclass_locations', 'location', 'user_location', 'masters', 'main_repo',
 		'missing_repo_name', 'name', 'priority', 'sync', 'format', 'sign_manifest', 'thin_manifest',
 		'allow_missing_manifest', 'create_manifest', 'disable_manifest', 'cache_is_authoritative',
-		'trust_authoritative_cache', 'manifest_hash_flags']
+		'trust_authoritative_cache', 'manifest_hashes']
 
 	def __init__(self, name, repo_opts):
 		"""Build a RepoConfig with options in repo_opts
@@ -118,7 +118,7 @@ class RepoConfig(object):
 		self.allow_missing_manifest = False
 		self.create_manifest = True
 		self.disable_manifest = False
-		self.manifest_hash_flags = {}
+		self.manifest_hashes = None
 
 		self.cache_is_authoritative = False
 
@@ -131,7 +131,7 @@ class RepoConfig(object):
 		kwds['thin'] = self.thin_manifest
 		kwds['allow_missing'] = self.allow_missing_manifest
 		kwds['allow_create'] = self.create_manifest
-		kwds['hash_flags'] = self.manifest_hash_flags
+		kwds['hashes'] = self.manifest_hashes
 		if self.disable_manifest:
 			kwds['from_scratch'] = True
 		return manifest.Manifest(*args, **kwds)
@@ -382,21 +382,10 @@ class RepoConfigLoader(object):
 			repo.create_manifest = manifest_policy != 'false'
 			repo.disable_manifest = manifest_policy == 'false'
 
-			if 'manifest-rmd160' in layout_data:
-				repo.manifest_hash_flags["RMD160"] = \
-					layout_data['manifest-rmd160'].lower() == 'true'
-
-			if 'manifest-sha1' in layout_data:
-				repo.manifest_hash_flags["SHA1"] = \
-					layout_data['manifest-sha1'].lower() == 'true'
-
-			if 'manifest-sha256' in layout_data:
-				repo.manifest_hash_flags["SHA256"] = \
-					layout_data['manifest-sha256'].lower() == 'true'
-
-			if 'manifest-whirlpool' in layout_data:
-				repo.manifest_hash_flags["WHIRLPOOL"] = \
-					layout_data['manifest-whirlpool'].lower() == 'true'
+			manifest_hashes = layout_data.get('manifest-hashes')
+			if manifest_hashes is not None:
+				manifest_hashes = frozenset(manifest_hashes.upper().split())
+			repo.manifest_hashes = manifest_hashes
 
 			repo.cache_is_authoritative = layout_data.get('authoritative-cache', 'false').lower() == 'true'
 			if not repo.trust_authoritative_cache: