lib/cache_unittest.py

# Copyright 2015 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Unittests for the cache.py module."""

from __future__ import print_function

import mock
import os

from chromite.lib import gs_unittest
from chromite.lib import cros_test_lib
from chromite.lib import cache
from chromite.lib import osutils
from chromite.lib import partial_mock
from chromite.lib import retry_util


class CacheReferenceTest(cros_test_lib.TestCase):
  """Tests for CacheReference.

  Largely focused on exercising the API other objects expect from it.
  """

  # pylint: disable=protected-access

  def setUp(self):
    # These are the funcs CacheReference expects the cache object to have.
    spec = (
        '_GetKeyPath',
        '_Insert',
        '_InsertText',
        '_KeyExists',
        '_LockForKey',
        '_Remove',
    )
    self.cache = mock.Mock(spec=spec)
    self.lock = mock.MagicMock()
    self.cache._LockForKey.return_value = self.lock

  def testContext(self):
    """Verify we can use it as a context manager."""
    # We should set the acquire member and grab/release the lock.
    ref = cache.CacheReference(self.cache, 'key')
    self.assertFalse(ref.acquired)
    self.assertFalse(self.lock.__enter__.called)
    with ref as newref:
      self.assertEqual(ref, newref)
      self.assertTrue(ref.acquired)
      self.assertTrue(self.lock.__enter__.called)
      self.assertFalse(self.lock.__exit__.called)
    self.assertFalse(ref.acquired)
    self.assertTrue(self.lock.__exit__.called)

  def testPath(self):
    """Verify we get a file path for the ref."""
    self.cache._GetKeyPath.return_value = '/foo/bar'

    ref = cache.CacheReference(self.cache, 'key')
    self.assertEqual(ref.path, '/foo/bar')

    self.cache._GetKeyPath.assert_called_once_with('key')

  def testLocking(self):
    """Verify Acquire & Release work as expected."""
    ref = cache.CacheReference(self.cache, 'key')

    # Check behavior when the lock is free.
    self.assertRaises(AssertionError, ref.Release)
    self.assertFalse(ref.acquired)

    # Check behavior when the lock is held.
    self.assertEqual(ref.Acquire(), None)
    self.assertRaises(AssertionError, ref.Acquire)
    self.assertTrue(ref.acquired)

    # Check behavior after the lock is freed.
    self.assertEqual(ref.Release(), None)
    self.assertFalse(ref.acquired)

  def testExists(self):
    """Verify Exists works when the entry is not in the cache."""
    ref = cache.CacheReference(self.cache, 'key')
    self.cache._KeyExists.return_value = False
    self.assertFalse(ref.Exists())

  def testExistsMissing(self):
    """Verify Exists works when the entry is in the cache."""
    ref = cache.CacheReference(self.cache, 'key')
    self.cache._KeyExists.return_value = True
    self.assertTrue(ref.Exists())

  def testAssign(self):
    """Verify Assign works as expected."""
    ref = cache.CacheReference(self.cache, 'key')
    ref.Assign('/foo')
    self.cache._Insert.assert_called_once_with('key', '/foo')

  def testAssignText(self):
    """Verify AssignText works as expected."""
    ref = cache.CacheReference(self.cache, 'key')
    ref.AssignText('text!')
    self.cache._InsertText.assert_called_once_with('key', 'text!')

  def testRemove(self):
    """Verify Remove works as expected."""
    ref = cache.CacheReference(self.cache, 'key')
    ref.Remove()
    self.cache._Remove.assert_called_once_with('key')

  def testSetDefault(self):
    """Verify SetDefault works when the entry is not in the cache."""
    ref = cache.CacheReference(self.cache, 'key')
    self.cache._KeyExists.return_value = False
    ref.SetDefault('/foo')
    self.cache._Insert.assert_called_once_with('key', '/foo')

  def testSetDefaultExists(self):
    """Verify SetDefault works when the entry is in the cache."""
    ref = cache.CacheReference(self.cache, 'key')
    self.cache._KeyExists.return_value = True
    ref.SetDefault('/foo')
    self.assertFalse(self.cache._Insert.called)


class CacheTestCase(cros_test_lib.MockTempDirTestCase):
  """Tests for any type of Cache object."""

  def setUp(self):
    self.gs_mock = self.StartPatcher(gs_unittest.GSContextMock())

  def _testAssign(self):
    """Verify we can assign a file to the cache and get it back out."""
    key = ('foo', 'bar')
    data = r'text!\nthere'

    path = os.path.join(self.tempdir, 'test-file')
    osutils.WriteFile(path, data)

    with self.cache.Lookup(key) as ref:
      self.assertFalse(ref.Exists())
      ref.Assign(path)
      self.assertTrue(ref.Exists())
      self.assertEqual(osutils.ReadFile(ref.path), data)

    with self.cache.Lookup(key) as ref:
      self.assertTrue(ref.Exists())
      self.assertEqual(osutils.ReadFile(ref.path), data)

  def _testAssignData(self):
    """Verify we can assign data to the cache and get it back out."""
    key = ('foo', 'bar')
    data = r'text!\nthere'

    with self.cache.Lookup(key) as ref:
      self.assertFalse(ref.Exists())
      ref.AssignText(data)
      self.assertTrue(ref.Exists())
      self.assertEqual(osutils.ReadFile(ref.path), data)

    with self.cache.Lookup(key) as ref:
      self.assertTrue(ref.Exists())
      self.assertEqual(osutils.ReadFile(ref.path), data)

  def _testRemove(self):
    """Verify we can remove entries from the cache."""
    key = ('foo', 'bar')
    data = r'text!\nthere'

    with self.cache.Lookup(key) as ref:
      self.assertFalse(ref.Exists())
      ref.AssignText(data)
      self.assertTrue(ref.Exists())
      ref.Remove()
      self.assertFalse(ref.Exists())


class DiskCacheTest(CacheTestCase):
  """Tests for DiskCache."""

  def setUp(self):
    self.cache = cache.DiskCache(self.tempdir)

  testAssign = CacheTestCase._testAssign
  testAssignData = CacheTestCase._testAssignData
  testRemove = CacheTestCase._testRemove


class RemoteCacheTest(CacheTestCase):
  """Tests for RemoteCache."""

  def setUp(self):
    self.cache = cache.RemoteCache(self.tempdir)

  testAssign = CacheTestCase._testAssign
  testAssignData = CacheTestCase._testAssignData
  testRemove = CacheTestCase._testRemove

  def testFetchFile(self):
    """Verify we handle file:// URLs."""
    key = ('file', 'foo')
    data = 'daaaaata'

    path = os.path.join(self.tempdir, 'test-file')
    url = 'file://%s' % path
    osutils.WriteFile(path, data)

    with self.cache.Lookup(key) as ref:
      self.assertFalse(ref.Exists())
      ref.Assign(url)
      self.assertTrue(ref.Exists())
      self.assertEqual(osutils.ReadFile(ref.path), data)

  def testFetchNonGs(self):
    """Verify we fetch remote URLs and save the result."""
    def _Fetch(*args, **_kwargs):
      # Probably shouldn't assume this ordering, but best way for now.
      cmd = args[0]
      local_path = cmd[-1]
      osutils.Touch(local_path)
    self.PatchObject(retry_util, 'RunCurl', side_effect=_Fetch)

    schemes = ('ftp', 'http', 'https')
    for scheme in schemes:
      key = (scheme, 'foo')
      url = '%s://some.site.localdomain/file_go_boom' % scheme
      with self.cache.Lookup(key) as ref:
        self.assertFalse(ref.Exists())
        ref.Assign(url)
        self.assertTrue(ref.Exists())

  def testFetchGs(self):
    """Verify we fetch from Google Storage and save the result."""
    # pylint: disable=unused-argument
    def _Fetch(_ctx, cmd, capture_output):
      # Touch file we tried to copy too.
      osutils.Touch(cmd[-1])

    self.gs_mock.AddCmdResult(
        ['cp', '-v', '--', partial_mock.Ignore(), partial_mock.Ignore()],
        side_effect=_Fetch)

    key = ('gs',)
    url = 'gs://some.site.localdomain/file_go_boom'
    with self.cache.Lookup(key) as ref:
      self.assertFalse(ref.Exists())
      ref.Assign(url)
      self.assertTrue(ref.Exists())


class TarballCacheTest(CacheTestCase):
  """Tests for TarballCache."""

  def setUp(self):
    self.cache = cache.RemoteCache(self.tempdir)

  testAssign = CacheTestCase._testAssign
  testAssignData = CacheTestCase._testAssignData
  testRemove = CacheTestCase._testRemove