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  # Copyright 2011 OpenStack Foundation
  # 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.
  
  from contextlib import contextmanager
  import datetime
  import hashlib
  import os
  import StringIO
  import tempfile
  import time
  
  import fixtures
  import stubout
  
  from glance.common import exception
  from glance import image_cache
  #NOTE(bcwaldon): This is imported to load the registry config options
  import glance.registry
  import glance.store.filesystem as fs_store
  import glance.store.s3 as s3_store
  from glance.tests import utils as test_utils
  from glance.tests.utils import skip_if_disabled, xattr_writes_supported
  
  FIXTURE_LENGTH = 1024
  FIXTURE_DATA = '*' * FIXTURE_LENGTH
  
  
  class ImageCacheTestCase(object):
  
      def _setup_fixture_file(self):
          FIXTURE_FILE = StringIO.StringIO(FIXTURE_DATA)
  
          self.assertFalse(self.cache.is_cached(1))
  
          self.assertTrue(self.cache.cache_image_file(1, FIXTURE_FILE))
  
          self.assertTrue(self.cache.is_cached(1))
  
      @skip_if_disabled
      def test_is_cached(self):
          """Verify is_cached(1) returns 0, then add something to the cache
          and verify is_cached(1) returns 1.
          """
          self._setup_fixture_file()
  
      @skip_if_disabled
      def test_read(self):
          """Verify is_cached(1) returns 0, then add something to the cache
          and verify after a subsequent read from the cache that
          is_cached(1) returns 1.
          """
          self._setup_fixture_file()
  
          buff = StringIO.StringIO()
          with self.cache.open_for_read(1) as cache_file:
              for chunk in cache_file:
                  buff.write(chunk)
  
          self.assertEqual(FIXTURE_DATA, buff.getvalue())
  
      @skip_if_disabled
      def test_open_for_read(self):
          """Test convenience wrapper for opening a cache file via
          its image identifier.
          """
          self._setup_fixture_file()
  
          buff = StringIO.StringIO()
          with self.cache.open_for_read(1) as cache_file:
              for chunk in cache_file:
                  buff.write(chunk)
  
          self.assertEqual(FIXTURE_DATA, buff.getvalue())
  
      @skip_if_disabled
      def test_get_image_size(self):
          """Test convenience wrapper for querying cache file size via
          its image identifier.
          """
          self._setup_fixture_file()
  
          size = self.cache.get_image_size(1)
  
          self.assertEqual(FIXTURE_LENGTH, size)
  
      @skip_if_disabled
      def test_delete(self):
          """Test delete method that removes an image from the cache."""
          self._setup_fixture_file()
  
          self.cache.delete_cached_image(1)
  
          self.assertFalse(self.cache.is_cached(1))
  
      @skip_if_disabled
      def test_delete_all(self):
          """Test delete method that removes an image from the cache."""
          for image_id in (1, 2):
              self.assertFalse(self.cache.is_cached(image_id))
  
          for image_id in (1, 2):
              FIXTURE_FILE = StringIO.StringIO(FIXTURE_DATA)
              self.assertTrue(self.cache.cache_image_file(image_id,
                                                          FIXTURE_FILE))
  
          for image_id in (1, 2):
              self.assertTrue(self.cache.is_cached(image_id))
  
          self.cache.delete_all_cached_images()
  
          for image_id in (1, 2):
              self.assertFalse(self.cache.is_cached(image_id))
  
      @skip_if_disabled
      def test_clean_stalled(self):
          """Test the clean method removes expected images."""
          incomplete_file_path = os.path.join(self.cache_dir, 'incomplete', '1')
          incomplete_file = open(incomplete_file_path, 'w')
          incomplete_file.write(FIXTURE_DATA)
          incomplete_file.close()
  
          self.assertTrue(os.path.exists(incomplete_file_path))
  
          self.cache.clean(stall_time=0)
  
          self.assertFalse(os.path.exists(incomplete_file_path))
  
      @skip_if_disabled
      def test_clean_stalled_nonzero_stall_time(self):
          """
          Test the clean method removes the stalled images as expected
          """
          incomplete_file_path_1 = os.path.join(self.cache_dir,
                                                'incomplete', '1')
          incomplete_file_path_2 = os.path.join(self.cache_dir,
                                                'incomplete', '2')
          for f in (incomplete_file_path_1, incomplete_file_path_2):
              incomplete_file = open(f, 'w')
              incomplete_file.write(FIXTURE_DATA)
              incomplete_file.close()
  
          mtime = os.path.getmtime(incomplete_file_path_1)
          pastday = datetime.datetime.fromtimestamp(mtime) - \
              datetime.timedelta(days=1)
          atime = int(time.mktime(pastday.timetuple()))
          mtime = atime
          os.utime(incomplete_file_path_1, (atime, mtime))
  
          self.assertTrue(os.path.exists(incomplete_file_path_1))
          self.assertTrue(os.path.exists(incomplete_file_path_2))
  
          self.cache.clean(stall_time=3600)
  
          self.assertFalse(os.path.exists(incomplete_file_path_1))
          self.assertTrue(os.path.exists(incomplete_file_path_2))
  
      @skip_if_disabled
      def test_prune(self):
          """
          Test that pruning the cache works as expected...
          """
          self.assertEqual(0, self.cache.get_cache_size())
  
          # Add a bunch of images to the cache. The max cache
          # size for the cache is set to 5KB and each image is
          # 1K. We add 10 images to the cache and then we'll
          # prune it. We should see only 5 images left after
          # pruning, and the images that are least recently accessed
          # should be the ones pruned...
          for x in xrange(10):
              FIXTURE_FILE = StringIO.StringIO(FIXTURE_DATA)
              self.assertTrue(self.cache.cache_image_file(x,
                                                          FIXTURE_FILE))
  
          self.assertEqual(10 * 1024, self.cache.get_cache_size())
  
          # OK, hit the images that are now cached...
          for x in xrange(10):
              buff = StringIO.StringIO()
              with self.cache.open_for_read(x) as cache_file:
                  for chunk in cache_file:
                      buff.write(chunk)
  
          self.cache.prune()
  
          self.assertEqual(5 * 1024, self.cache.get_cache_size())
  
          for x in xrange(0, 5):
              self.assertFalse(self.cache.is_cached(x),
                               "Image %s was cached!" % x)
  
          for x in xrange(5, 10):
              self.assertTrue(self.cache.is_cached(x),
                              "Image %s was not cached!" % x)
  
      @skip_if_disabled
      def test_prune_to_zero(self):
          """Test that an image_cache_max_size of 0 doesn't kill the pruner
  
          This is a test specifically for LP #1039854
          """
          self.assertEqual(0, self.cache.get_cache_size())
  
          FIXTURE_FILE = StringIO.StringIO(FIXTURE_DATA)
          self.assertTrue(self.cache.cache_image_file('xxx', FIXTURE_FILE))
  
          self.assertEqual(1024, self.cache.get_cache_size())
  
          # OK, hit the image that is now cached...
          buff = StringIO.StringIO()
          with self.cache.open_for_read('xxx') as cache_file:
              for chunk in cache_file:
                  buff.write(chunk)
  
          self.config(image_cache_max_size=0)
          self.cache.prune()
  
          self.assertEqual(0, self.cache.get_cache_size())
          self.assertFalse(self.cache.is_cached('xxx'))
  
      @skip_if_disabled
      def test_queue(self):
          """
          Test that queueing works properly
          """
  
          self.assertFalse(self.cache.is_cached(1))
          self.assertFalse(self.cache.is_queued(1))
  
          FIXTURE_FILE = StringIO.StringIO(FIXTURE_DATA)
  
          self.assertTrue(self.cache.queue_image(1))
  
          self.assertTrue(self.cache.is_queued(1))
          self.assertFalse(self.cache.is_cached(1))
  
          # Should not return True if the image is already
          # queued for caching...
          self.assertFalse(self.cache.queue_image(1))
  
          self.assertFalse(self.cache.is_cached(1))
  
          # Test that we return False if we try to queue
          # an image that has already been cached
  
          self.assertTrue(self.cache.cache_image_file(1, FIXTURE_FILE))
  
          self.assertFalse(self.cache.is_queued(1))
          self.assertTrue(self.cache.is_cached(1))
  
          self.assertFalse(self.cache.queue_image(1))
  
          self.cache.delete_cached_image(1)
  
          for x in xrange(3):
              self.assertTrue(self.cache.queue_image(x))
  
          self.assertEqual(self.cache.get_queued_images(),
                           ['0', '1', '2'])
  
      def test_open_for_write_good(self):
          """
          Test to see if open_for_write works in normal case
          """
  
          # test a good case
          image_id = '1'
          self.assertFalse(self.cache.is_cached(image_id))
          with self.cache.driver.open_for_write(image_id) as cache_file:
              cache_file.write('a')
          self.assertTrue(self.cache.is_cached(image_id),
                          "Image %s was NOT cached!" % image_id)
          # make sure it has tidied up
          incomplete_file_path = os.path.join(self.cache_dir,
                                              'incomplete', image_id)
          invalid_file_path = os.path.join(self.cache_dir, 'invalid', image_id)
          self.assertFalse(os.path.exists(incomplete_file_path))
          self.assertFalse(os.path.exists(invalid_file_path))
  
      def test_open_for_write_with_exception(self):
          """
          Test to see if open_for_write works in a failure case for each driver
          This case is where an exception is raised while the file is being
          written. The image is partially filled in cache and filling wont resume
          so verify the image is moved to invalid/ directory
          """
          # test a case where an exception is raised while the file is open
          image_id = '1'
          self.assertFalse(self.cache.is_cached(image_id))
          try:
              with self.cache.driver.open_for_write(image_id) as cache_file:
                  raise IOError
          except Exception as e:
              self.assertEqual(type(e), IOError)
          self.assertFalse(self.cache.is_cached(image_id),
                           "Image %s was cached!" % image_id)
          # make sure it has tidied up
          incomplete_file_path = os.path.join(self.cache_dir,
                                              'incomplete', image_id)
          invalid_file_path = os.path.join(self.cache_dir, 'invalid', image_id)
          self.assertFalse(os.path.exists(incomplete_file_path))
          self.assertTrue(os.path.exists(invalid_file_path))
  
      def test_caching_iterator(self):
          """
          Test to see if the caching iterator interacts properly with the driver
          When the iterator completes going through the data the driver should
          have closed the image and placed it correctly
          """
          # test a case where an exception NOT raised while the file is open,
          # and a consuming iterator completes
          def consume(image_id):
              data = ['a', 'b', 'c', 'd', 'e', 'f']
              checksum = None
              caching_iter = self.cache.get_caching_iter(image_id, checksum,
                                                         iter(data))
              self.assertEqual(list(caching_iter), data)
  
          image_id = '1'
          self.assertFalse(self.cache.is_cached(image_id))
          consume(image_id)
          self.assertTrue(self.cache.is_cached(image_id),
                          "Image %s was NOT cached!" % image_id)
          # make sure it has tidied up
          incomplete_file_path = os.path.join(self.cache_dir,
                                              'incomplete', image_id)
          invalid_file_path = os.path.join(self.cache_dir, 'invalid', image_id)
          self.assertFalse(os.path.exists(incomplete_file_path))
          self.assertFalse(os.path.exists(invalid_file_path))
  
      def test_caching_iterator_handles_backend_failure(self):
          """
          Test that when the backend fails, caching_iter does not continue trying
          to consume data, and rolls back the cache.
          """
          def faulty_backend():
              data = ['a', 'b', 'c', 'Fail', 'd', 'e', 'f']
              for d in data:
                  if d == 'Fail':
                      raise exception.GlanceException('Backend failure')
                  yield d
  
          def consume(image_id):
              caching_iter = self.cache.get_caching_iter(image_id, None,
                                                         faulty_backend())
              # excercise the caching_iter
              list(caching_iter)
  
          image_id = '1'
          self.assertRaises(exception.GlanceException, consume, image_id)
          # make sure bad image was not cached
          self.assertFalse(self.cache.is_cached(image_id))
  
      def test_caching_iterator_falloffend(self):
          """
          Test to see if the caching iterator interacts properly with the driver
          in a case where the iterator is only partially consumed. In this case
          the image is only partially filled in cache and filling wont resume.
          When the iterator goes out of scope the driver should have closed the
          image and moved it from incomplete/ to invalid/
          """
          # test a case where a consuming iterator just stops.
          def falloffend(image_id):
              data = ['a', 'b', 'c', 'd', 'e', 'f']
              checksum = None
              caching_iter = self.cache.get_caching_iter(image_id, checksum,
                                                         iter(data))
              self.assertEqual(caching_iter.next(), 'a')
  
          image_id = '1'
          self.assertFalse(self.cache.is_cached(image_id))
          falloffend(image_id)
          self.assertFalse(self.cache.is_cached(image_id),
                           "Image %s was cached!" % image_id)
          # make sure it has tidied up
          incomplete_file_path = os.path.join(self.cache_dir,
                                              'incomplete', image_id)
          invalid_file_path = os.path.join(self.cache_dir, 'invalid', image_id)
          self.assertFalse(os.path.exists(incomplete_file_path))
          self.assertTrue(os.path.exists(invalid_file_path))
  
      def test_gate_caching_iter_good_checksum(self):
          image = "12345678990abcdefghijklmnop"
          image_id = 123
  
          md5 = hashlib.md5()
          md5.update(image)
          checksum = md5.hexdigest()
  
          cache = image_cache.ImageCache()
          img_iter = cache.get_caching_iter(image_id, checksum, image)
          for chunk in img_iter:
              pass
          # checksum is valid, fake image should be cached:
          self.assertTrue(cache.is_cached(image_id))
  
      def test_gate_caching_iter_fs_chunked_file(self):
          """Tests get_caching_iter when using a filesystem ChunkedFile"""
          image_id = 123
  
          with tempfile.NamedTemporaryFile() as test_data_file:
              test_data_file.write(FIXTURE_DATA)
              test_data_file.seek(0)
              image = fs_store.ChunkedFile(test_data_file.name)
              md5 = hashlib.md5()
              md5.update(FIXTURE_DATA)
              checksum = md5.hexdigest()
  
              cache = image_cache.ImageCache()
              img_iter = cache.get_caching_iter(image_id, checksum, image)
              for chunk in img_iter:
                  pass
              # checksum is valid, fake image should be cached:
              self.assertTrue(cache.is_cached(image_id))
  
      def test_gate_caching_iter_s3_chunked_file(self):
          """Tests get_caching_iter when using an S3 ChunkedFile"""
          image_id = 123
  
          with tempfile.NamedTemporaryFile() as test_data_file:
              test_data_file.write(FIXTURE_DATA)
              test_data_file.seek(0)
              image = s3_store.ChunkedFile(test_data_file)
              md5 = hashlib.md5()
              md5.update(FIXTURE_DATA)
              checksum = md5.hexdigest()
  
              cache = image_cache.ImageCache()
              img_iter = cache.get_caching_iter(image_id, checksum, image)
              for chunk in img_iter:
                  pass
              # checksum is valid, fake image should be cached:
              self.assertTrue(cache.is_cached(image_id))
  
      def test_gate_caching_iter_bad_checksum(self):
          image = "12345678990abcdefghijklmnop"
          image_id = 123
          checksum = "foobar"  # bad.
  
          cache = image_cache.ImageCache()
          img_iter = cache.get_caching_iter(image_id, checksum, image)
  
          def reader():
              for chunk in img_iter:
                  pass
          self.assertRaises(exception.GlanceException, reader)
          # checksum is invalid, caching will fail:
          self.assertFalse(cache.is_cached(image_id))
  
  
  class TestImageCacheXattr(test_utils.BaseTestCase,
                            ImageCacheTestCase):
  
      """Tests image caching when xattr is used in cache"""
  
      def setUp(self):
          """
          Test to see if the pre-requisites for the image cache
          are working (python-xattr installed and xattr support on the
          filesystem)
          """
          super(TestImageCacheXattr, self).setUp()
  
          if getattr(self, 'disable', False):
              return
  
          self.cache_dir = self.useFixture(fixtures.TempDir()).path
  
          if not getattr(self, 'inited', False):
              try:
                  import xattr
              except ImportError:
                  self.inited = True
                  self.disabled = True
                  self.disabled_message = ("python-xattr not installed.")
                  return
  
          self.inited = True
          self.disabled = False
          self.config(image_cache_dir=self.cache_dir,
                      image_cache_driver='xattr',
                      image_cache_max_size=1024 * 5)
          self.cache = image_cache.ImageCache()
  
          if not xattr_writes_supported(self.cache_dir):
              self.inited = True
              self.disabled = True
              self.disabled_message = ("filesystem does not support xattr")
              return
  
  
  class TestImageCacheSqlite(test_utils.BaseTestCase,
                             ImageCacheTestCase):
  
      """Tests image caching when SQLite is used in cache"""
  
      def setUp(self):
          """
          Test to see if the pre-requisites for the image cache
          are working (python-sqlite3 installed)
          """
          super(TestImageCacheSqlite, self).setUp()
  
          if getattr(self, 'disable', False):
              return
  
          if not getattr(self, 'inited', False):
              try:
                  import sqlite3
              except ImportError:
                  self.inited = True
                  self.disabled = True
                  self.disabled_message = ("python-sqlite3 not installed.")
                  return
  
          self.inited = True
          self.disabled = False
          self.cache_dir = self.useFixture(fixtures.TempDir()).path
          self.config(image_cache_dir=self.cache_dir,
                      image_cache_driver='sqlite',
                      image_cache_max_size=1024 * 5)
          self.cache = image_cache.ImageCache()
  
  
  class TestImageCacheNoDep(test_utils.BaseTestCase):
  
      def setUp(self):
          super(TestImageCacheNoDep, self).setUp()
  
          self.driver = None
  
          def init_driver(self2):
              self2.driver = self.driver
  
          self.stubs = stubout.StubOutForTesting()
          self.stubs.Set(image_cache.ImageCache, 'init_driver', init_driver)
          self.addCleanup(self.stubs.UnsetAll)
  
      def test_get_caching_iter_when_write_fails(self):
  
          class FailingFile(object):
  
              def write(self, data):
                  if data == "Fail":
                      raise IOError
  
          class FailingFileDriver(object):
  
              def is_cacheable(self, *args, **kwargs):
                  return True
  
              @contextmanager
              def open_for_write(self, *args, **kwargs):
                  yield FailingFile()
  
          self.driver = FailingFileDriver()
          cache = image_cache.ImageCache()
          data = ['a', 'b', 'c', 'Fail', 'd', 'e', 'f']
  
          caching_iter = cache.get_caching_iter('dummy_id', None, iter(data))
          self.assertEqual(list(caching_iter), data)
  
      def test_get_caching_iter_when_open_fails(self):
  
          class OpenFailingDriver(object):
  
              def is_cacheable(self, *args, **kwargs):
                  return True
  
              @contextmanager
              def open_for_write(self, *args, **kwargs):
                  raise IOError
  
          self.driver = OpenFailingDriver()
          cache = image_cache.ImageCache()
          data = ['a', 'b', 'c', 'd', 'e', 'f']
  
          caching_iter = cache.get_caching_iter('dummy_id', None, iter(data))
          self.assertEqual(list(caching_iter), data)
  