From 65264a936a6c9d0a8c4eae69acaee2c3ee54b5d6 Mon Sep 17 00:00:00 2001
From: pandatt <guojy8993@163.com>
Date: Thu, 9 May 2019 10:48:48 +0800
Subject: [PATCH] Add sort_keys retrieving function

This patch provides a tool function to retrieve valid sort keys
from `attr_info` dict. And it's necessary prerequisite to fix
bug-1659175.

Related-bug: #1659175
Change-Id: I5ef7a0730122011f5ef18c1b4e2c0bfe82ed585b
---
 neutron_lib/api/attributes.py                 | 13 +++++++++++
 neutron_lib/tests/unit/api/test_attributes.py | 23 +++++++++++++++++++
 ...s-from-attribute-map-ae53d67e0be2ace0.yaml |  5 ++++
 3 files changed, 41 insertions(+)
 create mode 100644 releasenotes/notes/add-retrieve-sort-keys-from-attribute-map-ae53d67e0be2ace0.yaml

diff --git a/neutron_lib/api/attributes.py b/neutron_lib/api/attributes.py
index 6a19aae28..4eb30acc8 100644
--- a/neutron_lib/api/attributes.py
+++ b/neutron_lib/api/attributes.py
@@ -297,3 +297,16 @@ def _core_resource_attributes():
 
 # populate core resources into singleton global
 RESOURCES = _core_resource_attributes()
+
+
+def retrieve_valid_sort_keys(attr_info):
+    """Retrieve sort keys from `attr_info` dict.
+
+    Iterate the `attr_info`, filter and return the attributes that are
+    defined with `is_sort_key=True`.
+
+    :param attr_info: The attribute dict for common neutron resource.
+    :returns: Set of sort keys.
+    """
+    return set(attr for attr, schema in attr_info.items()
+               if schema.get('is_sort_key', False))
diff --git a/neutron_lib/tests/unit/api/test_attributes.py b/neutron_lib/tests/unit/api/test_attributes.py
index c9d031399..496e366dd 100644
--- a/neutron_lib/tests/unit/api/test_attributes.py
+++ b/neutron_lib/tests/unit/api/test_attributes.py
@@ -321,3 +321,26 @@ class TestValidatePriviliges(base.BaseTestCase):
             attributes._validate_privileges(ctx, res_dict)
         except exc.HTTPBadRequest:
             self.fail("HTTPBadRequest exception should not be raised.")
+
+
+class TestRetrieveValidSortKeys(base.BaseTestCase):
+
+    def test_retrieve_valid_sort_keys(self):
+        attr_info = {
+            "id": {
+                "visible": True,
+                "is_sort_key": True
+            },
+            "name": {
+                "is_sort_key": True
+            },
+            "created_at": {
+                "is_sort_key": False
+            },
+            "tenant_id": {
+                "visible": True,
+            }
+        }
+        expect_val = set(["id", "name"])
+        actual_val = attributes.retrieve_valid_sort_keys(attr_info)
+        self.assertEqual(expect_val, actual_val)
diff --git a/releasenotes/notes/add-retrieve-sort-keys-from-attribute-map-ae53d67e0be2ace0.yaml b/releasenotes/notes/add-retrieve-sort-keys-from-attribute-map-ae53d67e0be2ace0.yaml
new file mode 100644
index 000000000..19880e2f0
--- /dev/null
+++ b/releasenotes/notes/add-retrieve-sort-keys-from-attribute-map-ae53d67e0be2ace0.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    A new method ``retrieve_valid_sort_keys`` was added to ``neutron_lib.api.attributes``.
+    This method can help retrieve valid sort keys from a given resource attribute map.