1 files changed, 83 insertions, 0 deletions
diff --git a/nova/validate.py b/nova/validate.py
new file mode 100644
index 000000000..d1358d402
--- /dev/null
+++ b/nova/validate.py
@@ -0,0 +1,83 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+# Copyright [2010] [Anso Labs, LLC]
+#
+#    Licensed under the Apache License, Version 2.0 (the "License");
+#    you may not use this file except in compliance with the License.
+#    You may obtain a copy of the License at
+#
+#        http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS,
+#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#    See the License for the specific language governing permissions and
+#    limitations under the License.
+
+"""
+  Decorators for argument validation, courtesy of 
+  http://rmi.net/~lutz/rangetest.html
+"""
+
+def rangetest(**argchecks):                 # validate ranges for both+defaults
+    def onDecorator(func):                  # onCall remembers func and argchecks
+        import sys
+        code = func.__code__ if sys.version_info[0] == 3 else func.func_code
+        allargs  = code.co_varnames[:code.co_argcount]
+        funcname = func.__name__
+        
+        def onCall(*pargs, **kargs):
+            # all pargs match first N args by position
+            # the rest must be in kargs or omitted defaults
+            positionals = list(allargs)
+            positionals = positionals[:len(pargs)]
+
+            for (argname, (low, high)) in argchecks.items():
+                # for all args to be checked
+                if argname in kargs:
+                    # was passed by name
+                    if kargs[argname] < low or kargs[argname] > high:
+                        errmsg = '{0} argument "{1}" not in {2}..{3}'
+                        errmsg = errmsg.format(funcname, argname, low, high)
+                        raise TypeError(errmsg)
+
+                elif argname in positionals:
+                    # was passed by position
+                    position = positionals.index(argname)
+                    if pargs[position] < low or pargs[position] > high:
+                        errmsg = '{0} argument "{1}" not in {2}..{3}'
+                        errmsg = errmsg.format(funcname, argname, low, high)
+                        raise TypeError(errmsg)
+                else:
+                    pass
+
+            return func(*pargs, **kargs)    # okay: run original call
+        return onCall
+    return onDecorator
+
+def typetest(**argchecks):
+    def onDecorator(func):
+        import sys
+        code = func.__code__ if sys.version_info[0] == 3 else func.func_code
+        allargs  = code.co_varnames[:code.co_argcount]
+        funcname = func.__name__
+    
+        def onCall(*pargs, **kargs):
+            positionals = list(allargs)[:len(pargs)]
+            for (argname, type) in argchecks.items():
+                 if argname in kargs:
+                    if not isinstance(kargs[argname], type):
+                        errmsg = '{0} argument "{1}" not of type {2}'
+                        errmsg = errmsg.format(funcname, argname, type)
+                        raise TypeError(errmsg)
+                elif argname in positionals:
+                    position = positionals.index(argname)
+                    if not isinstance(pargs[position], type):
+                        errmsg = '{0} argument "{1}" not of type {2}'
+                        errmsg = errmsg.format(funcname, argname, type)
+                        raise TypeError(errmsg)
+                else:
+                    pass
+            return func(*pargs, **kargs)
+        return onCall
+    return onDecorator
+