Implement UI support for manifest lists

image/docker/interfaces.py

@@ -46,6 +46,12 @@ class ManifestInterface(object):
     """
     pass
 
+  @abstractproperty
+  def layers_compressed_size(self):
+    """ Returns the total compressed size of all the layers in this manifest. Returns None if this
+        cannot be computed locally.
+    """
+
   @abstractproperty
   def blob_digests(self):
     """ Returns an iterator over all the blob digests referenced by this manifest,

image/docker/schema1.py

@@ -251,6 +251,10 @@ class DockerSchema1Manifest(ManifestInterface):
   def manifest_dict(self):
     return self._parsed
 
+  @property
+  def layers_compressed_size(self):
+    return None
+
   @property
   def digest(self):
     return digest_tools.sha256_digest(self._payload)

image/docker/schema2/list.py

@@ -228,6 +228,10 @@ class DockerSchema2ManifestList(ManifestInterface):
   def local_blob_digests(self):
     return self.blob_digests
 
+  @property
+  def layers_compressed_size(self):
+    return None
+
   @lru_cache(maxsize=1)
   def manifests(self, lookup_manifest_fn):
     """ Returns the manifests in the list. The `lookup_manifest_fn` is a function

image/docker/schema2/manifest.py

@@ -169,6 +169,10 @@ class DockerSchema2Manifest(ManifestInterface):
       self._layers = list(self._generate_layers())
     return self._layers
 
+  @property
+  def layers_compressed_size(self):
+    return sum(layer.compressed_size for layer in self.layers)
+
   @property
   def leaf_layer(self):
     return self.layers[-1]