This function is called extremely frequently with similar arguments, so
this optimization reduces "emerge -uDvpU --with-bdeps=y @world" runtime from
43.5 -> 34.5s -- a 25.8% speedup.
---
lib/portage/dep/__init__.py | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/lib/portage/dep/__init__.py b/lib/portage/dep/__init__.py
index 72988357a..df296dd81 100644
--- a/lib/portage/dep/__init__.py
+++ b/lib/portage/dep/__init__.py
@@ -404,6 +404,8 @@ def paren_enclose(mylist, unevaluated_atom=False,
opconvert=False):
mystrparts.append(x)
return " ".join(mystrparts)
+_use_reduce_cache = {}
+
def use_reduce(depstr, uselist=(), masklist=(), matchall=False, excludeall=(),
is_src_uri=False, \
eapi=None, opconvert=False, flat=False, is_valid_flag=None,
token_class=None, matchnone=False,
subset=None):
@@ -440,6 +442,27 @@ def use_reduce(depstr, uselist=(), masklist=(),
matchall=False, excludeall=(), i
@rtype: List
@return: The use reduced depend array
"""
+ uselist_key = None
+ masklist_key = None
+ excludeall_key = None
+ subset_key = None
+ if uselist is not None:
+ uselist_key = tuple(uselist)
+ if masklist is not None:
+ masklist_key = tuple(masklist)
+ if excludeall is not None:
+ excludeall_key = tuple(excludeall)
+ if subset is not None:
+ subset_key = tuple(subset)
+ cache_key = (depstr, uselist_key, masklist_key, matchall,
excludeall_key, \
+ is_src_uri, eapi, opconvert, flat, is_valid_flag, token_class, \
+ matchnone, subset_key)
+
+ cache_entry = _use_reduce_cache.get(cache_key)
+ if cache_entry is not None:
+ # The list returned by this function may be modified, so return
a copy.
+ return cache_entry[:]
+
if isinstance(depstr, list):
if portage._internal_caller:
warnings.warn(_("Passing paren_reduced dep arrays to %s
is deprecated. " + \
@@ -767,6 +790,9 @@ def use_reduce(depstr, uselist=(), masklist=(),
matchall=False, excludeall=(), i
raise InvalidDependString(
_("Missing file name at end of string"))
+ # The list returned by this function may be modified, so store a copy.
+ _use_reduce_cache[cache_key] = stack[0][:]
+
return stack[0]
def dep_opconvert(deplist):
--
2.27.0.212.ge8ba1cc988-goog
