Faster cache lookup by removing a join with the ImagePlacementTable, removing the extra loop to add the locations and filtering the images looked up by the base image

test/test_imagetree.py

@@ -91,6 +91,27 @@ class TestImageTree(unittest.TestCase):
     self.assertEquals('staging', tree.tag_containing_image(result[0]))
 
 
+  def test_longest_path_simple_repo_direct_lookup(self):
+    repository = model.get_repository(NAMESPACE, SIMPLE_REPO)
+    all_images = list(model.get_repository_images(NAMESPACE, SIMPLE_REPO))
+    all_tags = list(model.list_repository_tags(NAMESPACE, SIMPLE_REPO))
+
+    base_image = self._get_base_image(all_images)
+    tag_image = all_tags[0].image
+
+    def checker(index, image):
+      return True
+
+    filtered_images = model.get_repository_images_directly(repository, with_ancestor=base_image)
+    self.assertEquals(set([f.id for f in filtered_images]), set([a.id for a in all_images]))
+
+    tree = ImageTree(filtered_images, all_tags)
+
+    ancestors = tag_image.ancestors.split('/')[2:-1] # Skip the first image.
+    result = tree.find_longest_path(base_image.id, checker)
+    self.assertEquals(3, len(result))
+    self.assertEquals('latest', tree.tag_containing_image(result[-1]))
+
 if __name__ == '__main__':
   unittest.main()