Add an ImageTree class and change to searching *all applicable* branches when looking for the best cache tag.

test/test_imagetree.py

@@ -0,0 +1,96 @@
+import unittest
+
+from app import app
+from util.imagetree import ImageTree
+from initdb import setup_database_for_testing, finished_database_for_testing
+from data import model
+
+NAMESPACE = 'devtable'
+SIMPLE_REPO = 'simple'
+COMPLEX_REPO = 'complex'
+
+class TestImageTree(unittest.TestCase):
+  def setUp(self):
+    setup_database_for_testing(self)
+    self.app = app.test_client()
+    self.ctx = app.test_request_context()
+    self.ctx.__enter__()
+
+  def tearDown(self):
+    finished_database_for_testing(self)
+    self.ctx.__exit__(True, None, None)
+
+  def _get_base_image(self, all_images):
+    for image in all_images:
+      if image.ancestors == '/':
+        return image
+
+    return None
+
+  def test_longest_path_simple_repo(self):
+    all_images = list(model.get_repository_images(NAMESPACE, SIMPLE_REPO))
+    all_tags = list(model.list_repository_tags(NAMESPACE, SIMPLE_REPO))
+    tree = ImageTree(all_images, all_tags)
+
+    base_image = self._get_base_image(all_images)
+    tag_image = all_tags[0].image
+
+    def checker(index, image):
+      return True
+
+    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))
+    for index in range(0, 2):
+      self.assertEquals(int(ancestors[index]), result[index].id)
+
+    self.assertEquals('latest', tree.tag_containing_image(result[-1]))
+
+  def test_longest_path_complex_repo(self):
+    all_images = list(model.get_repository_images(NAMESPACE, COMPLEX_REPO))
+    all_tags = list(model.list_repository_tags(NAMESPACE, COMPLEX_REPO))
+    tree = ImageTree(all_images, all_tags)
+
+    base_image = self._get_base_image(all_images)
+
+    def checker(index, image):
+      return True
+
+    result = tree.find_longest_path(base_image.id, checker)
+    self.assertEquals(4, len(result))
+    self.assertEquals('v2.0', tree.tag_containing_image(result[-1]))
+
+  def test_filtering(self):
+    all_images = list(model.get_repository_images(NAMESPACE, COMPLEX_REPO))
+    all_tags = list(model.list_repository_tags(NAMESPACE, COMPLEX_REPO))
+    tree = ImageTree(all_images, all_tags, parent_filter=1245)
+
+    base_image = self._get_base_image(all_images)
+
+    def checker(index, image):
+      return True
+
+    result = tree.find_longest_path(base_image.id, checker)
+    self.assertEquals(0, len(result))
+
+  def test_find_tag_parent_image(self):
+    all_images = list(model.get_repository_images(NAMESPACE, COMPLEX_REPO))
+    all_tags = list(model.list_repository_tags(NAMESPACE, COMPLEX_REPO))
+    tree = ImageTree(all_images, all_tags)
+
+    base_image = self._get_base_image(all_images)
+
+    def checker(index, image):
+      return True
+
+    result = tree.find_longest_path(base_image.id, checker)
+    self.assertEquals(4, len(result))
+
+    # Only use the first two images. They don't have tags, but the method should
+    # still return the tag that contains them.
+    self.assertEquals('v2.0', tree.tag_containing_image(result[0]))
+
+
+if __name__ == '__main__':
+  unittest.main()
+