[catapult] - Copy Telemetry's gsutilz over to third_party.

third_party/gsutil/gslib/tests/test_file_part.py

+# -*- coding: utf-8 -*-
+# Copyright 2013 Google Inc. 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.
+"""Unit tests for FilePart class."""
+
+from __future__ import absolute_import
+
+import os
+
+from gslib.file_part import FilePart
+import gslib.tests.testcase as testcase
+
+
+# pylint: disable=protected-access
+class TestFilePart(testcase.GsUtilUnitTestCase):
+  """Unit tests for FilePart class."""
+
+  def test_tell(self):
+    filename = 'test_tell'
+    contents = 100 * 'x'
+    fpath = self.CreateTempFile(file_name=filename, contents=contents)
+    part_length = 23
+    start_pos = 50
+    fp = FilePart(fpath, start_pos, part_length)
+    self.assertEqual(start_pos, fp._fp.tell())
+    self.assertEqual(0, fp.tell())
+
+  def test_seek(self):
+    """Tests seeking in a FilePart."""
+    filename = 'test_seek'
+    contents = 100 * 'x'
+    part_length = 23
+    start_pos = 50
+    fpath = self.CreateTempFile(file_name=filename, contents=contents)
+    fp = FilePart(fpath, start_pos, part_length)
+    offset = 10
+
+    # Absolute positioning.
+    fp.seek(offset)
+    self.assertEqual(start_pos + offset, fp._fp.tell())
+    self.assertEqual(offset, fp.tell())
+
+    # Relative positioning.
+    fp.seek(offset, whence=os.SEEK_CUR)
+    self.assertEqual(start_pos + 2 * offset, fp._fp.tell())
+    self.assertEqual(2 * offset, fp.tell())
+
+    # Absolute positioning from EOF.
+    fp.seek(-offset, whence=os.SEEK_END)
+    self.assertEqual(start_pos + part_length - offset, fp._fp.tell())
+    self.assertEqual(part_length - offset, fp.tell())
+
+    # Seek past EOF.
+    fp.seek(1, whence=os.SEEK_END)
+    self.assertEqual(start_pos + part_length + 1, fp._fp.tell())
+    self.assertEqual(part_length + 1, fp.tell())
+
+  def test_read(self):
+    """Tests various reaad operations with FilePart."""
+    filename = 'test_read'
+    contents = ''
+    for i in range(1, 256):
+      contents += str(i)
+    part_length = 23
+    start_pos = 50
+    fpath = self.CreateTempFile(file_name=filename, contents=contents)
+
+    # Read in the whole file.
+    fp = FilePart(fpath, start_pos, part_length)
+    whole_file = fp.read()
+    self.assertEqual(contents[start_pos:(start_pos + part_length)], whole_file)
+
+    # Read in a piece of the file from the beginning.
+    fp.seek(0)
+    offset = 10
+    partial_file = fp.read(offset)
+    self.assertEqual(
+        contents[start_pos:(start_pos + offset)],
+        partial_file)
+
+    # Read in the rest of the file.
+    remaining_file = fp.read(part_length - offset)
+    self.assertEqual(
+        contents[(start_pos + offset):(start_pos + part_length)],
+        remaining_file)
+    self.assertEqual(
+        contents[start_pos:(start_pos + part_length)],
+        partial_file + remaining_file)
+
+    # Try to read after reaching EOF.
+    empty_file = fp.read(100)
+    self.assertEqual('', empty_file)
+
+    empty_file = fp.read()
+    self.assertEqual('', empty_file)