Remove unused Scope argument from artifact name related APIs.tristan/artifact-dependency-names

Additionally, this reverts terminology back to calling these "artifact names",
and not "artifact refs", which is a terminology which crept in from various
underlying implementations.

Summary of changes:

  * _artifact.py:

    - get_dependency_refs() renamed to get_dependency_artifact_names()
    - get_dependency_artifact_names() loses the Scope argument
    - Consequently, a huge and needless XXX comment is removed

  * _artifactelement.py:

    - _new_from_artifact_ref() renamed to _new_from_artifact_name()
    - get_dependency_refs() renamed to get_dependency_artifact_names()
    - get_dependency_artifact_names() loses the Scope argument

  * _project.py:

    - Now call _new_from_artifact_name()
    - Removes a legacy XXX comment which is not particularly relevant

  * element.py:

    - __get_dependency_refs() renamed to __get_dependency_artifact_names()
    - Adapt __get_last_build_artifact() to updated API names.

4 files changed, 28 insertions, 61 deletions

diff --git a/src/buildstream/_artifact.py b/src/buildstream/_artifact.py
index ac33f041c..f74f3f9ff 100644
--- a/src/buildstream/_artifact.py
+++ b/src/buildstream/_artifact.py
@@ -30,7 +30,6 @@ artifact composite interaction away from Element class
 
 import os
 
-from ._exceptions import ArtifactError
 from ._protos.buildstream.v2.artifact_pb2 import Artifact as ArtifactProto
 from . import _yaml
 from . import utils
@@ -362,46 +361,28 @@ class Artifact:
 
         return self._metadata_workspaced_dependencies
 
-    # get_dependency_refs()
+    # get_dependency_artifact_names()
     #
-    # Retrieve the artifact refs of the artifact's dependencies
-    #
-    # Args:
-    #    deps (Scope): The scope of dependencies
+    # Retrieve the artifact names of all of the dependencies in Scope.BUILD
     #
     # Returns:
     #    (list [str]): A list of refs of all build dependencies in staging order.
     #
-    def get_dependency_refs(self, deps=Scope.BUILD):
+    def get_dependency_artifact_names(self):
         # XXX: The pylint disable is necessary due to upstream issue:
         # https://github.com/PyCQA/pylint/issues/850
         from .element import _get_normal_name  # pylint: disable=cyclic-import
 
-        # Extract the proto
         artifact = self._get_proto()
-
-        if deps == Scope.BUILD:
-            try:
-                dependency_refs = [
-                    os.path.join(dep.project_name, _get_normal_name(dep.element_name), dep.cache_key)
-                    for dep in artifact.build_deps
-                ]
-            except AttributeError:
-                # If the artifact has no dependencies
-                dependency_refs = []
-        elif deps == Scope.NONE:
-            dependency_refs = [self._element.get_artifact_name()]
-        else:
-            # XXX: We can only support obtaining the build dependencies of
-            #      an artifact. This is because this is the only information we store
-            #      in the proto. If we were to add runtime deps to the proto, we'd need
-            #      to include these in cache key calculation.
-            #
-            #      This would have some undesirable side effects:
-            #          1. It might trigger unnecessary rebuilds.
-            #          2. It would be impossible to support cyclic runtime dependencies
-            #             in the future
-            raise ArtifactError("Dependency scope: {} is not supported for artifacts".format(deps))
+        try:
+            dependency_refs = [
+                os.path.join(dep.project_name, _get_normal_name(dep.element_name), dep.cache_key)
+                for dep in artifact.build_deps
+            ]
+        except AttributeError:
+            # If the artifact has no dependencies, the build_deps attribute
+            # will be missing from the proto.
+            dependency_refs = []
 
         return dependency_refs
 
diff --git a/src/buildstream/_artifactelement.py b/src/buildstream/_artifactelement.py
index 44e52ea90..53a1ff72f 100644
--- a/src/buildstream/_artifactelement.py
+++ b/src/buildstream/_artifactelement.py
@@ -24,7 +24,6 @@ from . import _cachekey
 from ._exceptions import ArtifactElementError
 from ._loader import LoadElement
 from .node import Node
-from .types import Scope
 
 if TYPE_CHECKING:
     from typing import Dict
@@ -54,10 +53,10 @@ class ArtifactElement(Element):
 
         super().__init__(context, project, load_element, None)
 
-    # _new_from_artifact_ref():
+    # _new_from_artifact_name():
     #
     # Recursively instantiate a new ArtifactElement instance, and its
-    # dependencies from an artifact ref
+    # dependencies from an artifact name
     #
     # Args:
     #    ref (String): The artifact ref
@@ -68,7 +67,7 @@ class ArtifactElement(Element):
     #    (ArtifactElement): A newly created Element instance
     #
     @classmethod
-    def _new_from_artifact_ref(cls, ref, context, task=None):
+    def _new_from_artifact_name(cls, ref, context, task=None):
 
         if ref in cls.__instantiated_artifacts:
             return cls.__instantiated_artifacts[ref]
@@ -79,8 +78,8 @@ class ArtifactElement(Element):
         artifact_element._initialize_state()
         cls.__instantiated_artifacts[ref] = artifact_element
 
-        for dep_ref in artifact_element.get_dependency_refs(Scope.BUILD):
-            dependency = ArtifactElement._new_from_artifact_ref(dep_ref, context, task)
+        for dep_ref in artifact_element.get_dependency_artifact_names():
+            dependency = ArtifactElement._new_from_artifact_name(dep_ref, context, task)
             artifact_element._add_build_dependency(dependency)
 
         return artifact_element
@@ -112,19 +111,16 @@ class ArtifactElement(Element):
     def preflight(self):
         pass
 
-    # get_dependency_refs()
+    # get_dependency_artifact_names()
     #
-    # Obtain the refs of a particular scope of dependencies
-    #
-    # Args:
-    #   scope (Scope): The scope of dependencies for which we want to obtain the refs
+    # Retrieve the artifact names of all of the dependencies in Scope.BUILD
     #
     # Returns:
     #   (list [str]): A list of artifact refs
     #
-    def get_dependency_refs(self, scope=Scope.BUILD):
+    def get_dependency_artifact_names(self):
         artifact = self._get_artifact()
-        return artifact.get_dependency_refs(deps=scope)
+        return artifact.get_dependency_artifact_names()
 
     # configure_sandbox()
     #
diff --git a/src/buildstream/_project.py b/src/buildstream/_project.py
index 87772995a..209ba516c 100644
--- a/src/buildstream/_project.py
+++ b/src/buildstream/_project.py
@@ -467,16 +467,9 @@ class Project:
     #
     def load_artifacts(self, targets):
         with self._context.messenger.simple_task("Loading artifacts") as task:
-            # XXX: Here, we are explicitly checking for refs in the artifactdir
-            #      for two reasons:
-            #          1. The Project, or the Context, do not currently have
-            #             access to the ArtifactCache
-            #          2. The ArtifactCache.contains() method expects an Element
-            #             and a key, not a ref.
-            #
             artifacts = []
             for ref in targets:
-                artifacts.append(ArtifactElement._new_from_artifact_ref(ref, self._context, task))
+                artifacts.append(ArtifactElement._new_from_artifact_name(ref, self._context, task))
 
         ArtifactElement._clear_artifact_refs_cache()
 
diff --git a/src/buildstream/element.py b/src/buildstream/element.py
index 4995f1f37..4b53aa3dd 100644
--- a/src/buildstream/element.py
+++ b/src/buildstream/element.py
@@ -2259,20 +2259,17 @@ class Element(Plugin):
             if redundant_ref is not None:
                 self.__redundant_source_refs.append((source, redundant_ref))
 
-    # __get_dependency_refs()
+    # __get_dependency_artifact_names()
     #
-    # Retrieve the artifact refs of the element's dependencies
-    #
-    # Args:
-    #    scope (Scope): The scope of dependencies
+    # Retrieve the artifact names of all of the dependencies in Scope.BUILD
     #
     # Returns:
     #    (list [str]): A list of refs of all dependencies in staging order.
     #
-    def __get_dependency_refs(self, scope):
+    def __get_dependency_artifact_names(self):
         return [
             os.path.join(dep.project_name, _get_normal_name(dep.name), dep._get_cache_key())
-            for dep in self.dependencies(scope)
+            for dep in self.dependencies(Scope.BUILD)
         ]
 
     # __get_last_build_artifact()
@@ -2305,8 +2302,8 @@ class Element(Plugin):
 
         # Don't perform an incremental build if there has been a change in
         # build dependencies.
-        old_dep_refs = artifact.get_dependency_refs(Scope.BUILD)
-        new_dep_refs = self.__get_dependency_refs(Scope.BUILD)
+        old_dep_refs = artifact.get_dependency_artifact_names()
+        new_dep_refs = self.__get_dependency_artifact_names()
         if old_dep_refs != new_dep_refs:
             return None