projects.py: Optimize os_cascade()

Signed-off-by: Jan Lindemann <jan@janware.com>

scripts/projects.py

@@ -56,7 +56,7 @@ class ResultCache(object):
 class Build(object):
 
     def __init__(self):
-        self.__os_cascade = os_cascade()
+        pass
 
     def find_proj_path(self, name):
         name=name.replace("dspider-", "")
@@ -156,8 +156,9 @@ class Build(object):
         # -- check exclude
         exclude = get_modules_from_project_txt([ module ], 'build', 'exclude',
                 scope = 1, add_self=False, names_only=True)
+        cascade = os_cascade() + [ 'all' ]
         for p1 in exclude:
-            for p2 in self.__os_cascade + [ 'all' ]:
+            for p2 in cascade:
                 if p1 == p2:
                     print('| Configured to skip build on platform >' + p1 + '<')
                     print('`' + delim + ' <')
@@ -304,6 +305,9 @@ def htdocs_dir(name):
     return None
 
 def os_cascade():
+    global glob_os_cascade
+    if glob_os_cascade is not None:
+        return glob_os_cascade
     r = [ 'os', platform.system().lower() ]
     os = res_cache.run(get_os, [])
     name = re.sub('-.*', '', os)
@@ -320,6 +324,7 @@ def os_cascade():
 	r.append(os)
     # e.g. os, linux, suse, suse-tumbleweed
     #return [ 'os', platform.system().lower(), name, os ]
+    glob_os_cascade = r
     return r
 
 def strip_module_from_spec(mod):
@@ -819,6 +824,9 @@ res_cache = ResultCache()
 dep_cache = {}
 my_dir = os.path.dirname(os.path.realpath(__file__))
 do_debug = False
+topdir = None
+top_name = None
+glob_os_cascade = None
 
 skip = 0
 for a in sys.argv[1::]:
@@ -832,9 +840,6 @@ for a in sys.argv[1::]:
     if a[0] != '-':
         break
 
-topdir = None
-top_name = None
-
 parser = argparse.ArgumentParser(description='Project metadata evaluation')
 parser.add_argument('cmd', default='', help='Command')
 parser.add_argument('--debug', '-d', action='store_true',