Add unit tests for size_checked_iter

Change-Id: I3822d093571b02b2bb9a7d0b7d6cb4c1a0b9e812

glance/tests/unit/api/test_common.py

@@ -0,0 +1,124 @@
+# Copyright 2012 OpenStack, LLC
+# All Rights Reserved.
+#
+#    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
+
+import webob
+
+from glance.common import exception
+import glance.api.common
+
+
+class SimpleIterator(object):
+    def __init__(self, file_object, chunk_size):
+        self.file_object = file_object
+        self.chunk_size = chunk_size
+
+    def __iter__(self):
+        def read_chunk():
+            return self.fobj.read(self.chunk_size)
+
+        chunk = read_chunk()
+        while chunk:
+            yield chunk
+            chunk = read_chunk()
+        else:
+            raise StopIteration()
+
+
+class TestSizeCheckedIter(unittest.TestCase):
+    def _get_image_metadata(self):
+        return {'id': 'e31cb99c-fe89-49fb-9cc5-f5104fffa636'}
+
+    def _get_webob_response(self):
+        request = webob.Request.blank('/')
+        response = webob.Response()
+        response.request = request
+        return response
+
+    def test_uniform_chunk_size(self):
+        resp = self._get_webob_response()
+        meta = self._get_image_metadata()
+        checked_image = glance.api.common.size_checked_iter(
+                resp, meta, 4, ['AB', 'CD'], None)
+
+        self.assertEqual('AB', checked_image.next())
+        self.assertEqual('CD', checked_image.next())
+        self.assertRaises(StopIteration, checked_image.next)
+
+    def test_small_last_chunk(self):
+        resp = self._get_webob_response()
+        meta = self._get_image_metadata()
+        checked_image = glance.api.common.size_checked_iter(
+                resp, meta, 3, ['AB', 'C'], None)
+
+        self.assertEqual('AB', checked_image.next())
+        self.assertEqual('C', checked_image.next())
+        self.assertRaises(StopIteration, checked_image.next)
+
+    def test_variable_chunk_size(self):
+        resp = self._get_webob_response()
+        meta = self._get_image_metadata()
+        checked_image = glance.api.common.size_checked_iter(
+                resp, meta, 6, ['AB', '', 'CDE', 'F'], None)
+
+        self.assertEqual('AB', checked_image.next())
+        self.assertEqual('', checked_image.next())
+        self.assertEqual('CDE', checked_image.next())
+        self.assertEqual('F', checked_image.next())
+        self.assertRaises(StopIteration, checked_image.next)
+
+    def test_too_many_chunks(self):
+        """An image should streamed regardless of expected_size"""
+        resp = self._get_webob_response()
+        meta = self._get_image_metadata()
+        checked_image = glance.api.common.size_checked_iter(
+                resp, meta, 4, ['AB', 'CD', 'EF'], None)
+
+        self.assertEqual('AB', checked_image.next())
+        self.assertEqual('CD', checked_image.next())
+        self.assertEqual('EF', checked_image.next())
+        self.assertRaises(exception.GlanceException, checked_image.next)
+
+    def test_too_few_chunks(self):
+        resp = self._get_webob_response()
+        meta = self._get_image_metadata()
+        checked_image = glance.api.common.size_checked_iter(
+                 resp, meta, 6, ['AB', 'CD'], None)
+
+        self.assertEqual('AB', checked_image.next())
+        self.assertEqual('CD', checked_image.next())
+        self.assertRaises(exception.GlanceException, checked_image.next)
+
+    def test_too_much_data(self):
+        resp = self._get_webob_response()
+        meta = self._get_image_metadata()
+        checked_image = glance.api.common.size_checked_iter(
+                 resp, meta, 3, ['AB', 'CD'], None)
+
+        self.assertEqual('AB', checked_image.next())
+        self.assertEqual('CD', checked_image.next())
+        self.assertRaises(exception.GlanceException, checked_image.next)
+
+    def test_too_little_data(self):
+        resp = self._get_webob_response()
+        meta = self._get_image_metadata()
+        checked_image = glance.api.common.size_checked_iter(
+                 resp, meta, 6, ['AB', 'CD', 'E'], None)
+
+        self.assertEqual('AB', checked_image.next())
+        self.assertEqual('CD', checked_image.next())
+        self.assertEqual('E', checked_image.next())
+        self.assertRaises(exception.GlanceException, checked_image.next)