Add a CLIArgs Singleton class that will hold the parse cli arguments

lib/ansible/arguments.py

@@ -0,0 +1,83 @@
+# Copyright: (c) 2018, Toshio Kuratomi <tkuratomi@ansible.com>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+"""
+Hold command line arguments for use in other modules
+"""
+
+from abc import ABCMeta
+
+from ansible.module_utils.common._collections_compat import (Container, Mapping, Sequence, Set)
+from ansible.module_utils.common.collections import ImmutableDict
+from ansible.module_utils.six import add_metaclass, binary_type, text_type
+from ansible.utils.singleton import Singleton
+
+
+def _make_immutable(obj):
+    """Recursively convert a container and objects inside of it into immutable data types"""
+    if isinstance(obj, (text_type, binary_type)):
+        # Strings first because they are also sequences
+        return obj
+    elif isinstance(obj, Mapping):
+        temp_dict = {}
+        for key, value in obj.items():
+            if isinstance(value, Container):
+                temp_dict[key] = _make_immutable(value)
+            else:
+                temp_dict[key] = value
+        return ImmutableDict(temp_dict)
+    elif isinstance(obj, Set):
+        temp_set = set()
+        for value in obj:
+            if isinstance(value, Container):
+                temp_set.add(_make_immutable(value))
+            else:
+                temp_set.add(value)
+        return frozenset(temp_set)
+    elif isinstance(obj, Sequence):
+        temp_sequence = []
+        for value in obj:
+            if isinstance(value, Container):
+                temp_sequence.append(_make_immutable(value))
+            else:
+                temp_sequence.append(value)
+        return tuple(temp_sequence)
+
+    return obj
+
+
+class _ABCSingleton(Singleton, ABCMeta):
+    """
+    Combine ABCMeta based classes with Singleton based classes
+
+    Combine Singleton and ABCMeta so we have a metaclass that unambiguously knows which can override
+    the other.  Useful for making new types of containers which are also Singletons.
+    """
+    pass
+
+
+class CLIArgs(ImmutableDict):
+    """Hold a parsed copy of cli arguments"""
+    def __init__(self, mapping):
+        toplevel = {}
+        for key, value in mapping.items():
+            toplevel[key] = _make_immutable(value)
+        super(CLIArgs, self).__init__(toplevel)
+
+    @classmethod
+    def from_options(cls, options):
+        return cls(vars(options))
+
+
+@add_metaclass(_ABCSingleton)
+class GlobalCLIArgs(CLIArgs):
+    """
+    Globally hold a parsed copy of cli arguments.
+
+    Only one of these exist per program as it is for global context
+    """
+    pass

lib/ansible/module_utils/common/collections.py

@@ -1,4 +1,5 @@
-# Copyright (c), Sviatoslav Sydorenko <ssydoren@redhat.com> 2018
+# Copyright: (c) 2018, Sviatoslav Sydorenko <ssydoren@redhat.com>
+# Copyright: (c) 2018, Ansible Project
 # Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause)
 """Collection of low-level utility functions."""
 
@@ -7,7 +8,52 @@ __metaclass__ = type
 
 
 from ansible.module_utils.six import binary_type, text_type
-from ansible.module_utils.common._collections_compat import Sequence
+from ansible.module_utils.common._collections_compat import Hashable, Mapping, Sequence
+
+
+class ImmutableDict(Hashable, Mapping):
+    """Dictionary that cannot be updated"""
+    def __init__(self, *args, **kwargs):
+        self._store = dict(*args, **kwargs)
+
+    def __getitem__(self, key):
+        return self._store[key]
+
+    def __iter__(self):
+        return self._store.__iter__()
+
+    def __len__(self):
+        return self._store.__len__()
+
+    def __hash__(self):
+        return hash(frozenset(self.items()))
+
+    def __repr__(self):
+        return 'ImmutableDict({0})'.format(repr(self._store))
+
+    def union(self, overriding_mapping):
+        """
+        Create an ImmutableDict as a combination of the original and overriding_mapping
+
+        :arg overriding_mapping: A Mapping of replacement and additional items
+        :return: A copy of the ImmutableDict with key-value pairs from the overriding_mapping added
+
+        If any of the keys in overriding_mapping are already present in the original ImmutableDict,
+        the overriding_mapping item replaces the one in the original ImmutableDict.
+        """
+        return ImmutableDict(self._store, **overriding_mapping)
+
+    def difference(self, subtractive_iterable):
+        """
+        Create an ImmutableDict as a combination of the original minus keys in subtractive_iterable
+
+        :arg subtractive_iterable: Any iterable containing keys that should not be present in the
+            new ImmutableDict
+        :return: A copy of the ImmutableDict with keys from the subtractive_iterable removed
+        """
+        remove_keys = frozenset(subtractive_iterable)
+        keys = (k for k in self._store.keys() if k not in remove_keys)
+        return ImmutableDict((k, self._store[k]) for k in keys)
 
 
 def is_string(seq):