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diff --git a/keystone-moon/keystone/common/driver_hints.py b/keystone-moon/keystone/common/driver_hints.py
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+++ b/keystone-moon/keystone/common/driver_hints.py
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+# Copyright 2013 OpenStack Foundation
+# Copyright 2013 IBM Corp.
+#
+# 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.
+
+
+class Hints(object):
+    """Encapsulate driver hints for listing entities.
+
+    Hints are modifiers that affect the return of entities from a
+    list_<entities> operation.  They are typically passed to a driver to give
+    direction as to what filtering, pagination or list limiting actions are
+    being requested.
+
+    It is optional for a driver to action some or all of the list hints,
+    but any filters that it does satisfy must be marked as such by calling
+    removing the filter from the list.
+
+    A Hint object contains filters, which is a list of dicts that can be
+    accessed publicly. Also it contains a dict called limit, which will
+    indicate the amount of data we want to limit our listing to.
+
+    Each filter term consists of:
+
+    * ``name``: the name of the attribute being matched
+    * ``value``: the value against which it is being matched
+    * ``comparator``: the operation, which can be one of ``equals``,
+                      ``startswith`` or ``endswith``
+    * ``case_sensitive``: whether any comparison should take account of
+                          case
+    * ``type``: will always be 'filter'
+
+    """
+    def __init__(self):
+        self.limit = None
+        self.filters = list()
+
+    def add_filter(self, name, value, comparator='equals',
+                   case_sensitive=False):
+        """Adds a filter to the filters list, which is publicly accessible."""
+        self.filters.append({'name': name, 'value': value,
+                             'comparator': comparator,
+                             'case_sensitive': case_sensitive,
+                             'type': 'filter'})
+
+    def get_exact_filter_by_name(self, name):
+        """Return a filter key and value if exact filter exists for name."""
+        for entry in self.filters:
+            if (entry['type'] == 'filter' and entry['name'] == name and
+                    entry['comparator'] == 'equals'):
+                return entry
+
+    def set_limit(self, limit, truncated=False):
+        """Set a limit to indicate the list should be truncated."""
+        self.limit = {'limit': limit, 'type': 'limit', 'truncated': truncated}