Added Traverse Helper

Added Traverse Helper and unit-tests
Simplified generate UUID function

Change-Id: I307fc689e592b94e4e084d0e6a164e11c5ec4429

muranoapi/common/utils.py

@@ -13,12 +13,88 @@
 #    under the License.
 
 import eventlet
+import types
+from collections import deque
 from functools import wraps
 from muranoapi.openstack.common import log as logging
 
 log = logging.getLogger(__name__)
 
 
+class TraverseHelper(object):
+    @staticmethod
+    def get(path, source):
+        """
+        Provides the ability to traverse a data source made up of any
+        combination of lists and dicts.  Has simple rules for selecting item of
+        the list:
+        * each item should have id property
+        * to select item from the list, specify id value
+
+        Examples:
+            source = {'obj': {'attr': True}}
+            value = TraverseHelper.get('/obj/attr', source)
+
+            source = {'obj': [
+                {'id': '1', 'value': 1},
+                {'id': '2s', 'value': 2},
+            ]}
+            value = TraverseHelper.get('/obj/2s/value', source)
+
+
+        :param path: string with path to desired value
+        :param source: python object (list or dict)
+        :return: object
+        :raise: ValueError if object is malformed
+        """
+        if path.startswith('/'):
+            path = path[1:]
+
+        queue = deque(path.split('/'))
+        obj = source
+
+        while len(queue):
+            path = queue.popleft()
+
+            if isinstance(obj, types.ListType):
+                filtered = filter(lambda i: 'id' in i and i['id'] == path, obj)
+                obj = filtered[0] if filtered else None
+            elif isinstance(obj, types.DictionaryType):
+                obj = obj[path] if path else obj
+            else:
+                raise ValueError('Object or path is malformed')
+
+        return obj
+
+    @staticmethod
+    def update(path, value, source):
+        """
+        Updates value selected with specified path.
+
+        Warning: Root object could not be updated
+
+        :param path: string with path to desired value
+        :param value: value
+        :param source: python object (list or dict)
+        """
+        parent_path = '/'.join(path.split('/')[:-1])
+        node = TraverseHelper.get(parent_path, source)
+        key = path[1:].split('/')[-1]
+        node[key] = value
+
+    @staticmethod
+    def insert(path, value, source):
+        """
+        Inserts new item to selected list.
+
+        :param path: string with path to desired value
+        :param value: value
+        :param source: python object (list or dict)
+        """
+        node = TraverseHelper.get(path, source)
+        node.append(value)
+
+
 def retry(ExceptionToCheck, tries=4, delay=3, backoff=2):
     """Retry calling the decorated function using an exponential backoff.
 

muranoapi/common/uuidutils.py

@@ -16,4 +16,4 @@ import uuid
 
 
 def generate_uuid():
-    return str(uuid.uuid4()).replace('-', '')
+    return uuid.uuid4().hex

muranoapi/tests/common/__init__.py

@@ -0,0 +1,13 @@
+#    Copyright (c) 2013 Mirantis, Inc.
+#
+#    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.

muranoapi/tests/common/traverse_helper_tests.py

@@ -0,0 +1,70 @@
+#    Copyright (c) 2013 Mirantis, Inc.
+#
+#    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.
+import unittest
+from muranoapi.common.utils import TraverseHelper
+
+
+class TraverseHelperTests(unittest.TestCase):
+    def test_simple_root_get(self):
+        source = {"attr": True}
+        value = TraverseHelper.get('/', source)
+        self.assertEqual(value, {"attr": True})
+
+    def test_simple_attribute_get(self):
+        source = {"attr": True}
+        value = TraverseHelper.get('/attr', source)
+        self.assertEqual(value, True)
+
+    def test_attribute_get(self):
+        source = {'obj': {'attr': True}}
+        value = TraverseHelper.get('/obj/attr', source)
+        self.assertEqual(value, True)
+
+    def test_list_item_attribute_get_(self):
+        source = {'obj': [
+            {'id': '1', 'value': 1},
+            {'id': '2s', 'value': 2},
+        ]}
+        value = TraverseHelper.get('/obj/2s/value', source)
+        self.assertEqual(value, 2)
+
+    def test_simple_attribute_set(self):
+        source = {"attr": True}
+        TraverseHelper.update('/newAttr', False, source)
+        value = TraverseHelper.get('/newAttr', source)
+        self.assertEqual(value, False)
+
+    def test_simple_attribute_update(self):
+        source = {"attr": True}
+        TraverseHelper.update('/attr', False, source)
+        value = TraverseHelper.get('/attr', source)
+        self.assertEqual(value, False)
+
+    def test_attribute_update(self):
+        source = {"obj": {"attr": True}}
+        TraverseHelper.update('/obj/attr', False, source)
+        value = TraverseHelper.get('/obj/attr', source)
+        self.assertEqual(value, False)
+
+    def test_simple_adding_item_to_list(self):
+        source = {"attr": [1, 2, 3]}
+        TraverseHelper.insert('/attr', 4, source)
+        value = TraverseHelper.get('/attr', source)
+        self.assertEqual(value, [1, 2, 3, 4])
+
+    def test_adding_item_to_list(self):
+        source = {"obj": {"attr": [1, 2, 3]}}
+        TraverseHelper.insert('/obj/attr', 4, source)
+        value = TraverseHelper.get('/obj/attr', source)
+        self.assertEqual(value, [1, 2, 3, 4])