config: use frozenset for _constant_keys lookup

diff --git a/pym/portage/package/ebuild/config.py b/pym/portage/package/ebuild/config.py
index 9a8486c39b851966d449e328e60b4de84b1c53ef..f6166c65b6b9f0bf0452dadbb628d8540992ff6f 100644 (file)
--- a/pym/portage/package/ebuild/config.py
+++ b/pym/portage/package/ebuild/config.py
@@ -122,6 +122,9 @@ class config(object):
        virtuals ...etc you look in here.
        """
 
+       _constant_keys = frozenset(['PORTAGE_BIN_PATH', 'PORTAGE_GID',
+               'PORTAGE_PYM_PATH'])
+
        _setcpv_aux_keys = ('DEFINED_PHASES', 'DEPEND', 'EAPI',
                'INHERITED', 'IUSE', 'REQUIRED_USE', 'KEYWORDS', 'LICENSE', 'PDEPEND',
                'PROPERTIES', 'PROVIDE', 'RDEPEND', 'SLOT',
@@ -2126,14 +2129,16 @@ class config(object):
 
        def _getitem(self, mykey):
 
-               # These ones point to temporary values when
-               # portage plans to update itself.
-               if mykey == "PORTAGE_BIN_PATH":
-                       return portage._bin_path
-               elif mykey == "PORTAGE_PYM_PATH":
-                       return portage._pym_path
-               elif mykey == "PORTAGE_GID":
-                       return _unicode_decode(str(portage_gid))
+               if mykey in self._constant_keys:
+                       # These two point to temporary values when
+                       # portage plans to update itself.
+                       if mykey == "PORTAGE_BIN_PATH":
+                               return portage._bin_path
+                       elif mykey == "PORTAGE_PYM_PATH":
+                               return portage._pym_path
+
+                       elif mykey == "PORTAGE_GID":
+                               return _unicode_decode(str(portage_gid))
 
                for d in self.lookuplist:
                        try:
@@ -2186,9 +2191,7 @@ class config(object):
 
        def __iter__(self):
                keys = set()
-               keys.add("PORTAGE_BIN_PATH")
-               keys.add("PORTAGE_PYM_PATH")
-               keys.add("PORTAGE_GID")
+               keys.update(self._constant_keys)
                for d in self.lookuplist:
                        keys.update(d)
                return iter(keys)