Add utils.streaming test cases

Add  test cases for freezer.utils.streaming module

Change-Id: I2aa0aacd96c5c614fc2ef39e70d648c7921c056e

freezer/tests/unit/utils/test_streaming.py

@@ -0,0 +1,70 @@
+# (c) Copyright 2020 ZTE Corporation.
+#
+# 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 queue
+import unittest
+
+from freezer.utils import streaming
+
+
+class StreamingTestCase(unittest.TestCase):
+
+    def create_fifo(self, size):
+        input_queue = streaming.RichQueue(size)
+        read_except_queue = queue.Queue()
+        write_except_queue = queue.Queue()
+
+        read_stream = streaming.QueuedThread(self.backup_stream,
+                                             input_queue,
+                                             read_except_queue)
+
+        write_stream = streaming.QueuedThread(self.write_stream,
+                                              input_queue,
+                                              write_except_queue)
+
+        read_stream.daemon = True
+        write_stream.daemon = True
+        read_stream.start()
+        write_stream.start()
+        read_stream.join()
+        write_stream.join()
+
+        return input_queue
+
+    def backup_stream(self, rich_queue):
+        rich_queue.put_messages('ancd')
+
+    def write_stream(self, rich_queue):
+        for message in rich_queue.get_messages():
+            pass
+
+    def test_stream_1(self):
+        input_queue = self.create_fifo(1)
+        assert input_queue.finish_transmission is True
+
+    def test_stream_2(self):
+        input_queue = self.create_fifo(2)
+        assert input_queue.finish_transmission is True
+
+    def test_stream_3(self):
+        input_queue = self.create_fifo(3)
+        assert input_queue.finish_transmission is True
+
+    def test_stream_4(self):
+        input_queue = self.create_fifo(4)
+        assert input_queue.finish_transmission is True
+
+    def test_stream_5(self):
+        input_queue = self.create_fifo(5)
+        assert input_queue.finish_transmission is True