_artifact.py: Rework to use artifact proto

This will replace the previous use of a directory structure.
Quite a lot is changed here, predominantly _artifact and _artifactcache
modules.

Part of #974

11 files changed, 122 insertions, 52 deletions

diff --git a/tests/artifactcache/junctions.py b/tests/artifactcache/junctions.py
index d2eceb842..e1bbb31fd 100644
--- a/tests/artifactcache/junctions.py
+++ b/tests/artifactcache/junctions.py
@@ -69,6 +69,8 @@ def test_push_pull(cli, tmpdir, datafiles):
         #
         cas = os.path.join(cli.directory, 'cas')
         shutil.rmtree(cas)
+        artifact_dir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifact_dir)
 
         # Assert that nothing is cached locally anymore
         state = cli.get_element_state(project, 'target.bst')
diff --git a/tests/artifactcache/pull.py b/tests/artifactcache/pull.py
index 4f34156d7..cdadf583a 100644
--- a/tests/artifactcache/pull.py
+++ b/tests/artifactcache/pull.py
@@ -257,7 +257,8 @@ def test_pull_tree(cli, tmpdir, datafiles):
             utils._kill_process_tree(process.pid)
             raise
 
-        assert directory_hash and directory_size
+        # Directory size now zero with AaaP and stack element commit #1cbc5e63dc
+        assert directory_hash and not directory_size
 
         directory_digest = remote_execution_pb2.Digest(hash=directory_hash,
                                                        size_bytes=directory_size)
diff --git a/tests/artifactcache/push.py b/tests/artifactcache/push.py
index a099ad136..4f31148b7 100644
--- a/tests/artifactcache/push.py
+++ b/tests/artifactcache/push.py
@@ -4,7 +4,7 @@ import signal
 
 import pytest
 
-from buildstream import _yaml, _signals, utils
+from buildstream import _yaml, _signals, utils, Scope
 from buildstream._context import Context
 from buildstream._project import Project
 from buildstream._protos.build.bazel.remote.execution.v2 import remote_execution_pb2
@@ -85,7 +85,7 @@ def test_push(cli, tmpdir, datafiles):
         # See https://github.com/grpc/grpc/blob/master/doc/fork_support.md for details
         process = multiprocessing.Process(target=_queue_wrapper,
                                           args=(_test_push, queue, user_config_file, project_dir,
-                                                'target.bst', element_key))
+                                                'target.bst'))
 
         try:
             # Keep SIGINT blocked in the child process
@@ -102,7 +102,7 @@ def test_push(cli, tmpdir, datafiles):
         assert share.has_artifact(cli.get_artifact_name(project_dir, 'test', 'target.bst', cache_key=element_key))
 
 
-def _test_push(user_config_file, project_dir, element_name, element_key, queue):
+def _test_push(user_config_file, project_dir, element_name, queue):
     # Fake minimal context
     context = Context()
     context.load(config=user_config_file)
@@ -118,13 +118,22 @@ def _test_push(user_config_file, project_dir, element_name, element_key, queue):
     # Load the target element
     element = project.load_elements([element_name])[0]
 
+    # Ensure the element's artifact memeber is initialised
+    # This is duplicated from Pipeline.resolve_elements()
+    # as this test does not use the cli frontend.
+    for e in element.dependencies(Scope.ALL):
+        # Preflight
+        e._preflight()
+        # Determine initial element state.
+        e._update_state()
+
     # Manually setup the CAS remotes
     artifactcache.setup_remotes(use_config=True)
     artifactcache.initialize_remotes()
 
     if artifactcache.has_push_remotes(plugin=element):
         # Push the element's artifact
-        if not artifactcache.push(element, [element_key]):
+        if not element._push():
             queue.put("Push operation failed")
         else:
             queue.put(None)
diff --git a/tests/frontend/artifact.py b/tests/frontend/artifact.py
index 716c4b8a1..eb187a168 100644
--- a/tests/frontend/artifact.py
+++ b/tests/frontend/artifact.py
@@ -92,7 +92,7 @@ def test_artifact_delete_artifact(cli, tmpdir, datafiles):
     element = 'target.bst'
 
     # Configure a local cache
-    local_cache = os.path.join(str(tmpdir), 'artifacts')
+    local_cache = os.path.join(str(tmpdir), 'cache')
     cli.configure({'cachedir': local_cache})
 
     # First build an element so that we can find its artifact
@@ -104,7 +104,7 @@ def test_artifact_delete_artifact(cli, tmpdir, datafiles):
     artifact = os.path.join('test', os.path.splitext(element)[0], cache_key)
 
     # Explicitly check that the ARTIFACT exists in the cache
-    assert os.path.exists(os.path.join(local_cache, 'cas', 'refs', 'heads', artifact))
+    assert os.path.exists(os.path.join(local_cache, 'artifacts', 'refs', artifact))
 
     # Delete the artifact
     result = cli.run(project=project, args=['artifact', 'delete', artifact])
@@ -122,7 +122,7 @@ def test_artifact_delete_element_and_artifact(cli, tmpdir, datafiles):
     dep = 'compose-all.bst'
 
     # Configure a local cache
-    local_cache = os.path.join(str(tmpdir), 'artifacts')
+    local_cache = os.path.join(str(tmpdir), 'cache')
     cli.configure({'cachedir': local_cache})
 
     # First build an element so that we can find its artifact
@@ -138,14 +138,14 @@ def test_artifact_delete_element_and_artifact(cli, tmpdir, datafiles):
     artifact = os.path.join('test', os.path.splitext(element)[0], cache_key)
 
     # Explicitly check that the ARTIFACT exists in the cache
-    assert os.path.exists(os.path.join(local_cache, 'cas', 'refs', 'heads', artifact))
+    assert os.path.exists(os.path.join(local_cache, 'artifacts', 'refs', artifact))
 
     # Delete the artifact
     result = cli.run(project=project, args=['artifact', 'delete', artifact, dep])
     result.assert_success()
 
     # Check that the ARTIFACT is no longer in the cache
-    assert not os.path.exists(os.path.join(local_cache, 'cas', 'refs', 'heads', artifact))
+    assert not os.path.exists(os.path.join(local_cache, 'artifacts', artifact))
 
     # Check that the dependency ELEMENT is no longer cached
     assert cli.get_element_state(project, dep) != 'cached'
diff --git a/tests/frontend/pull.py b/tests/frontend/pull.py
index bf25ab1af..dccbbfde3 100644
--- a/tests/frontend/pull.py
+++ b/tests/frontend/pull.py
@@ -66,8 +66,10 @@ def test_push_pull_all(cli, tmpdir, datafiles):
         # Now we've pushed, delete the user's local artifact cache
         # directory and try to redownload it from the share
         #
-        cas = os.path.join(cli.directory, 'cas')
-        shutil.rmtree(cas)
+        casdir = os.path.join(cli.directory, 'cas')
+        shutil.rmtree(casdir)
+        artifactdir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifactdir)
 
         # Assert that nothing is cached locally anymore
         states = cli.get_element_states(project, all_elements)
@@ -116,8 +118,10 @@ def test_push_pull_default_targets(cli, tmpdir, datafiles):
         # Now we've pushed, delete the user's local artifact cache
         # directory and try to redownload it from the share
         #
-        artifacts = os.path.join(cli.directory, 'cas')
-        shutil.rmtree(artifacts)
+        casdir = os.path.join(cli.directory, 'cas')
+        shutil.rmtree(casdir)
+        artifactdir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifactdir)
 
         # Assert that nothing is cached locally anymore
         states = cli.get_element_states(project, all_elements)
@@ -158,8 +162,10 @@ def test_pull_secondary_cache(cli, tmpdir, datafiles):
         assert_shared(cli, share2, project, 'target.bst')
 
         # Delete the user's local artifact cache.
-        cas = os.path.join(cli.directory, 'cas')
-        shutil.rmtree(cas)
+        casdir = os.path.join(cli.directory, 'cas')
+        shutil.rmtree(casdir)
+        artifactdir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifactdir)
 
         # Assert that the element is not cached anymore.
         assert cli.get_element_state(project, 'target.bst') != 'cached'
@@ -212,8 +218,10 @@ def test_push_pull_specific_remote(cli, tmpdir, datafiles):
         # Now we've pushed, delete the user's local artifact cache
         # directory and try to redownload it from the good_share.
         #
-        cas = os.path.join(cli.directory, 'cas')
-        shutil.rmtree(cas)
+        casdir = os.path.join(cli.directory, 'cas')
+        shutil.rmtree(casdir)
+        artifactdir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifactdir)
 
         result = cli.run(project=project, args=['artifact', 'pull', 'target.bst', '--remote',
                                                 good_share.repo])
@@ -243,7 +251,7 @@ def test_push_pull_non_strict(cli, tmpdir, datafiles):
         result.assert_success()
         assert cli.get_element_state(project, 'target.bst') == 'cached'
 
-        # Assert that everything is now cached in the remote.
+        # Assert that everything is now cached in the reote.
         all_elements = ['target.bst', 'import-bin.bst', 'import-dev.bst', 'compose-all.bst']
         for element_name in all_elements:
             assert_shared(cli, share, project, element_name)
@@ -251,8 +259,10 @@ def test_push_pull_non_strict(cli, tmpdir, datafiles):
         # Now we've pushed, delete the user's local artifact cache
         # directory and try to redownload it from the share
         #
-        cas = os.path.join(cli.directory, 'cas')
-        shutil.rmtree(cas)
+        casdir = os.path.join(cli.directory, 'cas')
+        shutil.rmtree(casdir)
+        artifactdir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifactdir)
 
         # Assert that nothing is cached locally anymore
         for element_name in all_elements:
@@ -301,8 +311,10 @@ def test_push_pull_track_non_strict(cli, tmpdir, datafiles):
         # Now we've pushed, delete the user's local artifact cache
         # directory and try to redownload it from the share
         #
-        cas = os.path.join(cli.directory, 'cas')
-        shutil.rmtree(cas)
+        casdir = os.path.join(cli.directory, 'cas')
+        shutil.rmtree(casdir)
+        artifactdir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifactdir)
 
         # Assert that nothing is cached locally anymore
         for element_name in all_elements:
@@ -339,6 +351,8 @@ def test_push_pull_cross_junction(cli, tmpdir, datafiles):
 
         cache_dir = os.path.join(project, 'cache', 'cas')
         shutil.rmtree(cache_dir)
+        artifact_dir = os.path.join(project, 'cache', 'artifacts')
+        shutil.rmtree(artifact_dir)
 
         assert cli.get_element_state(project, 'junction.bst:import-etc.bst') == 'buildable'
 
@@ -372,8 +386,10 @@ def test_pull_missing_blob(cli, tmpdir, datafiles):
         # Now we've pushed, delete the user's local artifact cache
         # directory and try to redownload it from the share
         #
-        cas = os.path.join(cli.directory, 'cas')
-        shutil.rmtree(cas)
+        casdir = os.path.join(cli.directory, 'cas')
+        shutil.rmtree(casdir)
+        artifactdir = os.path.join(cli.directory, 'artifacts')
+        shutil.rmtree(artifactdir)
 
         # Assert that nothing is cached locally anymore
         for element_name in all_elements:
diff --git a/tests/frontend/remote-caches.py b/tests/frontend/remote-caches.py
index e3f10e6f7..089cf96e4 100644
--- a/tests/frontend/remote-caches.py
+++ b/tests/frontend/remote-caches.py
@@ -80,8 +80,9 @@ def test_source_artifact_caches(cli, tmpdir, datafiles):
         # remove the artifact from the repo and check it pulls sources, builds
         # and then pushes the artifacts
         shutil.rmtree(os.path.join(cachedir, 'cas'))
-        print(os.listdir(os.path.join(share.repodir, 'cas', 'refs', 'heads')))
-        shutil.rmtree(os.path.join(share.repodir, 'cas', 'refs', 'heads', 'test'))
+        shutil.rmtree(os.path.join(cachedir, 'artifacts'))
+        print(os.listdir(os.path.join(share.repodir, 'artifacts', 'refs')))
+        shutil.rmtree(os.path.join(share.repodir, 'artifacts', 'refs', 'test'))
 
         res = cli.run(project=project_dir, args=['build', 'repo.bst'])
         res.assert_success()
diff --git a/tests/integration/artifact.py b/tests/integration/artifact.py
index cb9f070d5..b942c1690 100644
--- a/tests/integration/artifact.py
+++ b/tests/integration/artifact.py
@@ -48,6 +48,7 @@ DATA_DIR = os.path.join(
 def test_cache_buildtrees(cli, tmpdir, datafiles):
     project = str(datafiles)
     element_name = 'autotools/amhello.bst'
+    cwd = str(tmpdir)
 
     # Create artifact shares for pull & push testing
     with create_artifact_share(os.path.join(str(tmpdir), 'share1')) as share1,\
@@ -68,20 +69,23 @@ def test_cache_buildtrees(cli, tmpdir, datafiles):
         assert share1.has_artifact(cli.get_artifact_name(project, 'test', element_name))
 
         # The buildtree dir should not exist, as we set the config to not cache buildtrees.
-        cache_key = cli.get_element_key(project, element_name)
-        elementdigest = share1.has_artifact(cli.get_artifact_name(project, 'test', element_name, cache_key=cache_key))
-        with cli.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
-            assert not os.path.isdir(buildtreedir)
+
+        artifact_name = cli.get_artifact_name(project, 'test', element_name)
+        assert share1.has_artifact(artifact_name)
+        with cli.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
+            assert not buildtreedir
 
         # Delete the local cached artifacts, and assert the when pulled with --pull-buildtrees
         # that is was cached in share1 as expected without a buildtree dir
         shutil.rmtree(os.path.join(str(tmpdir), 'cas'))
+        shutil.rmtree(os.path.join(str(tmpdir), 'artifacts'))
         assert cli.get_element_state(project, element_name) != 'cached'
         result = cli.run(project=project, args=['--pull-buildtrees', 'artifact', 'pull', element_name])
         assert element_name in result.get_pulled_elements()
-        with cli.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
-            assert not os.path.isdir(buildtreedir)
+        with cli.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
+            assert not buildtreedir
         shutil.rmtree(os.path.join(str(tmpdir), 'cas'))
+        shutil.rmtree(os.path.join(str(tmpdir), 'artifacts'))
 
         # Assert that the default behaviour of pull to not include buildtrees on the artifact
         # in share1 which was purposely cached with an empty one behaves as expected. As such the
@@ -89,9 +93,10 @@ def test_cache_buildtrees(cli, tmpdir, datafiles):
         # leading to no buildtreedir being extracted
         result = cli.run(project=project, args=['artifact', 'pull', element_name])
         assert element_name in result.get_pulled_elements()
-        with cli.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
-            assert not os.path.isdir(buildtreedir)
+        with cli.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
+            assert not buildtreedir
         shutil.rmtree(os.path.join(str(tmpdir), 'cas'))
+        shutil.rmtree(os.path.join(str(tmpdir), 'artifacts'))
 
         # Repeat building the artifacts, this time with cache-buildtrees set to
         # 'always' via the cli, as such the buildtree dir should not be empty
@@ -105,21 +110,22 @@ def test_cache_buildtrees(cli, tmpdir, datafiles):
         assert share2.has_artifact(cli.get_artifact_name(project, 'test', element_name))
 
         # Cache key will be the same however the digest hash will have changed as expected, so reconstruct paths
-        elementdigest = share2.has_artifact(cli.get_artifact_name(project, 'test', element_name, cache_key=cache_key))
-        with cli.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
+        with cli.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
             assert os.path.isdir(buildtreedir)
             assert os.listdir(buildtreedir)
 
         # Delete the local cached artifacts, and assert that when pulled with --pull-buildtrees
         # that it was cached in share2 as expected with a populated buildtree dir
         shutil.rmtree(os.path.join(str(tmpdir), 'cas'))
+        shutil.rmtree(os.path.join(str(tmpdir), 'artifacts'))
         assert cli.get_element_state(project, element_name) != 'cached'
         result = cli.run(project=project, args=['--pull-buildtrees', 'artifact', 'pull', element_name])
         assert element_name in result.get_pulled_elements()
-        with cli.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
+        with cli.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
             assert os.path.isdir(buildtreedir)
             assert os.listdir(buildtreedir)
         shutil.rmtree(os.path.join(str(tmpdir), 'cas'))
+        shutil.rmtree(os.path.join(str(tmpdir), 'artifacts'))
 
         # Clarify that the user config option for cache-buildtrees works as the cli
         # main option does. Point to share3 which does not have the artifacts cached to force
@@ -132,7 +138,6 @@ def test_cache_buildtrees(cli, tmpdir, datafiles):
         result = cli.run(project=project, args=['build', element_name])
         assert result.exit_code == 0
         assert cli.get_element_state(project, element_name) == 'cached'
-        elementdigest = share3.has_artifact(cli.get_artifact_name(project, 'test', element_name))
-        with cli.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
+        with cli.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
             assert os.path.isdir(buildtreedir)
             assert os.listdir(buildtreedir)
diff --git a/tests/integration/pullbuildtrees.py b/tests/integration/pullbuildtrees.py
index dfef18e7f..f37023e49 100644
--- a/tests/integration/pullbuildtrees.py
+++ b/tests/integration/pullbuildtrees.py
@@ -40,6 +40,7 @@ def default_state(cli, tmpdir, share):
 def test_pullbuildtrees(cli2, tmpdir, datafiles):
     project = str(datafiles)
     element_name = 'autotools/amhello.bst'
+    cwd = str(tmpdir)
 
     # Create artifact shares for pull & push testing
     with create_artifact_share(os.path.join(str(tmpdir), 'share1')) as share1,\
@@ -75,12 +76,12 @@ def test_pullbuildtrees(cli2, tmpdir, datafiles):
         # Also assert that the buildtree is added to the local CAS.
         result = cli2.run(project=project, args=['artifact', 'pull', element_name])
         assert element_name in result.get_pulled_elements()
-        elementdigest = share1.has_artifact(cli2.get_artifact_name(project, 'test', element_name))
-        with cli2.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
+        artifact_name = cli2.get_artifact_name(project, 'test', element_name)
+        with cli2.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
             assert not buildtreedir
         result = cli2.run(project=project, args=['--pull-buildtrees', 'artifact', 'pull', element_name])
         assert element_name in result.get_pulled_elements()
-        with cli2.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
+        with cli2.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
             assert os.path.isdir(buildtreedir)
         default_state(cli2, tmpdir, share1)
 
@@ -139,7 +140,7 @@ def test_pullbuildtrees(cli2, tmpdir, datafiles):
         result = cli2.run(project=project, args=['--pull-buildtrees', 'artifact', 'push', element_name])
         assert "Attempting to fetch missing artifact buildtrees" in result.stderr
         assert element_name not in result.get_pulled_elements()
-        with cli2.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
+        with cli2.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
             assert not buildtreedir
         assert element_name not in result.get_pushed_elements()
         assert not share3.has_artifact(cli2.get_artifact_name(project, 'test', element_name))
@@ -152,7 +153,7 @@ def test_pullbuildtrees(cli2, tmpdir, datafiles):
         result = cli2.run(project=project, args=['--pull-buildtrees', 'artifact', 'push', element_name])
         assert "Attempting to fetch missing artifact buildtrees" in result.stderr
         assert element_name in result.get_pulled_elements()
-        with cli2.artifact.extract_buildtree(tmpdir, elementdigest) as buildtreedir:
+        with cli2.artifact.extract_buildtree(cwd, cwd, artifact_name) as buildtreedir:
             assert os.path.isdir(buildtreedir)
         assert element_name in result.get_pushed_elements()
         assert share3.has_artifact(cli2.get_artifact_name(project, 'test', element_name))
diff --git a/tests/integration/shellbuildtrees.py b/tests/integration/shellbuildtrees.py
index d03344992..aa41eba36 100644
--- a/tests/integration/shellbuildtrees.py
+++ b/tests/integration/shellbuildtrees.py
@@ -196,6 +196,7 @@ def test_buildtree_pulled(cli, tmpdir, datafiles):
 
         # Discard the cache
         shutil.rmtree(str(os.path.join(str(tmpdir), 'cache', 'cas')))
+        shutil.rmtree(str(os.path.join(str(tmpdir), 'cache', 'artifacts')))
         assert cli.get_element_state(project, element_name) != 'cached'
 
         # Pull from cache, ensuring cli options is set to pull the buildtree
@@ -229,6 +230,7 @@ def test_buildtree_options(cli, tmpdir, datafiles):
 
         # Discard the cache
         shutil.rmtree(str(os.path.join(str(tmpdir), 'cache', 'cas')))
+        shutil.rmtree(str(os.path.join(str(tmpdir), 'cache', 'artifacts')))
         assert cli.get_element_state(project, element_name) != 'cached'
 
         # Pull from cache, but do not include buildtrees.
@@ -269,6 +271,7 @@ def test_buildtree_options(cli, tmpdir, datafiles):
         assert 'Attempting to fetch missing artifact buildtree' in res.stderr
         assert 'Hi' in res.output
         shutil.rmtree(os.path.join(os.path.join(str(tmpdir), 'cache', 'cas')))
+        shutil.rmtree(os.path.join(os.path.join(str(tmpdir), 'cache', 'artifacts')))
         assert cli.get_element_state(project, element_name) != 'cached'
 
         # Check it's not loading the shell at all with always set for the buildtree, when the
diff --git a/tests/sourcecache/fetch.py b/tests/sourcecache/fetch.py
index bc025cbd5..899e162aa 100644
--- a/tests/sourcecache/fetch.py
+++ b/tests/sourcecache/fetch.py
@@ -95,6 +95,7 @@ def test_source_fetch(cli, tmpdir, datafiles):
             os.path.join(str(tmpdir), 'cache', 'cas'),
             os.path.join(str(tmpdir), 'sourceshare', 'repo'))
         shutil.rmtree(os.path.join(str(tmpdir), 'cache', 'sources'))
+        shutil.rmtree(os.path.join(str(tmpdir), 'cache', 'artifacts'))
 
         digest = share.cas.resolve_ref(source._get_source_name())
         assert share.has_object(digest)
diff --git a/tests/testutils/artifactshare.py b/tests/testutils/artifactshare.py
index fca01497a..bc69a87d8 100644
--- a/tests/testutils/artifactshare.py
+++ b/tests/testutils/artifactshare.py
@@ -10,6 +10,7 @@ from buildstream._cas import CASCache
 from buildstream._cas.casserver import create_server
 from buildstream._exceptions import CASError
 from buildstream._protos.build.bazel.remote.execution.v2 import remote_execution_pb2
+from buildstream._protos.buildstream.v2 import artifact_pb2
 
 
 # ArtifactShare()
@@ -42,6 +43,8 @@ class ArtifactShare():
         #
         self.repodir = os.path.join(self.directory, 'repo')
         os.makedirs(self.repodir)
+        self.artifactdir = os.path.join(self.repodir, 'artifacts', 'refs')
+        os.makedirs(self.artifactdir)
 
         self.cas = CASCache(self.repodir)
 
@@ -126,17 +129,45 @@ class ArtifactShare():
     # Returns:
     #    (str): artifact digest if the artifact exists in the share, otherwise None.
     def has_artifact(self, artifact_name):
+
+        artifact_proto = artifact_pb2.Artifact()
+        artifact_path = os.path.join(self.artifactdir, artifact_name)
+
+        try:
+            with open(artifact_path, 'rb') as f:
+                artifact_proto.ParseFromString(f.read())
+        except FileNotFoundError:
+            return None
+
+        reachable = set()
+
+        def reachable_dir(digest):
+            self.cas._reachable_refs_dir(
+                reachable, digest, update_mtime=False, check_exists=True)
+
         try:
-            tree = self.cas.resolve_ref(artifact_name)
-            reachable = set()
-            try:
-                self.cas._reachable_refs_dir(reachable, tree, update_mtime=False, check_exists=True)
-            except FileNotFoundError:
-                return None
-            return tree
+            if str(artifact_proto.files):
+                reachable_dir(artifact_proto.files)
+
+            if str(artifact_proto.buildtree):
+                reachable_dir(artifact_proto.buildtree)
+
+            if str(artifact_proto.public_data):
+                if not os.path.exists(self.cas.objpath(artifact_proto.public_data)):
+                    return None
+
+            for log_file in artifact_proto.logs:
+                if not os.path.exists(self.cas.objpath(log_file.digest)):
+                    return None
+
+            return artifact_proto.files
+
         except CASError:
             return None
 
+        except FileNotFoundError:
+            return None
+
     # close():
     #
     # Remove the artifact share.