1 files changed, 112 insertions, 0 deletions
diff --git a/lib/ansible/module_utils/common/collections.py b/lib/ansible/module_utils/common/collections.py
new file mode 100644
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+++ b/lib/ansible/module_utils/common/collections.py
@@ -0,0 +1,112 @@
+# 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."""
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+from ansible.module_utils.six import binary_type, text_type
+from ansible.module_utils.common._collections_compat import Hashable, Mapping, MutableMapping, 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 __eq__(self, other):
+        try:
+            if self.__hash__() == hash(other):
+                return True
+        except TypeError:
+            pass
+
+        return False
+
+    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):
+    """Identify whether the input has a string-like type (inclding bytes)."""
+    # AnsibleVaultEncryptedUnicode inherits from Sequence, but is expected to be a string like object
+    return isinstance(seq, (text_type, binary_type)) or getattr(seq, '__ENCRYPTED__', False)
+
+
+def is_iterable(seq, include_strings=False):
+    """Identify whether the input is an iterable."""
+    if not include_strings and is_string(seq):
+        return False
+
+    try:
+        iter(seq)
+        return True
+    except TypeError:
+        return False
+
+
+def is_sequence(seq, include_strings=False):
+    """Identify whether the input is a sequence.
+
+    Strings and bytes are not sequences here,
+    unless ``include_string`` is ``True``.
+
+    Non-indexable things are never of a sequence type.
+    """
+    if not include_strings and is_string(seq):
+        return False
+
+    return isinstance(seq, Sequence)
+
+
+def count(seq):
+    """Returns a dictionary with the number of appearances of each element of the iterable.
+
+    Resembles the collections.Counter class functionality. It is meant to be used when the
+    code is run on Python 2.6.* where collections.Counter is not available. It should be
+    deprecated and replaced when support for Python < 2.7 is dropped.
+    """
+    if not is_iterable(seq):
+        raise Exception('Argument provided  is not an iterable')
+    counters = dict()
+    for elem in seq:
+        counters[elem] = counters.get(elem, 0) + 1
+    return counters