Skip whirlpool digest check when unaccelerated.

If multiple digests are available and whirlpool is unaccelerated, then
skip it. This allows extreme performance problems like bug #425046 to
be avoided whenever practical, especially for cases like stage builds
where acceleration may not be available for some hashes due to
minimization of dependencies.

1 files changed, 20 insertions, 0 deletions

diff --git a/pym/portage/checksum.py b/pym/portage/checksum.py
index bd416ac12..daf4a0cbf 100644
--- a/pym/portage/checksum.py
+++ b/pym/portage/checksum.py
@@ -137,8 +137,10 @@ try:
 except ImportError:
 	pass
 
+_whirlpool_unaccelerated = False
 if "WHIRLPOOL" not in hashfunc_map:
 	# Bundled WHIRLPOOL implementation
+	_whirlpool_unaccelerated = True
 	from portage.util.whirlpool import new as _new_whirlpool
 	whirlpoolhash = _generate_hash_function("WHIRLPOOL", _new_whirlpool, origin="bundled")
 
@@ -197,6 +199,24 @@ def get_hash_origin(hashtype):
 		raise KeyError(hashtype)
 	return hashorigin_map.get(hashtype, "unknown")
 
+def _filter_unaccelarated_hashes(digests):
+	"""
+	If multiple digests are available and some are unaccelerated,
+	then return a new dict that omits the unaccelerated ones. This
+	allows extreme performance problems like bug #425046 to be
+	avoided whenever practical, especially for cases like stage
+	builds where acceleration may not be available for some hashes
+	due to minimization of dependencies.
+	"""
+	if _whirlpool_unaccelerated and "WHIRLPOOL" in digests:
+		verifiable_hash_types = set(digests).intersection(hashfunc_map)
+		verifiable_hash_types.discard("size")
+		if len(verifiable_hash_types) > 1:
+			digests = dict(digests)
+			digests.pop("WHIRLPOOL")
+
+	return digests
+
 def verify_all(filename, mydict, calc_prelink=0, strict=0):
 	"""
 	Verify all checksums against a file.