cascache.py: Add pull_key_only

1 files changed, 23 insertions, 0 deletions

diff --git a/buildstream/_artifactcache/cascache.py b/buildstream/_artifactcache/cascache.py
index b95d38e9f..dce6a90b0 100644
--- a/buildstream/_artifactcache/cascache.py
+++ b/buildstream/_artifactcache/cascache.py
@@ -215,6 +215,29 @@ class CASCache(ArtifactCache):
             remotes_for_project = self._remotes[element._get_project()]
             return any(remote.spec.push for remote in remotes_for_project)
 
+
+    def pull_key_only(self, key, size_bytes, project):
+        """ Like pull but doesn't need an element and takes a key instead of a ref"""
+
+        for remote in self._remotes[project]:
+            try:
+                remote.init()
+
+                tree = remote_execution_pb2.Digest()
+                tree.hash = key
+                tree.size_bytes = size_bytes
+
+                self._fetch_directory(remote, tree)
+
+                # no need to pull from additional remotes
+                return True
+
+            except grpc.RpcError as e:
+                if e.code() != grpc.StatusCode.NOT_FOUND:
+                    raise
+
+        return False
+
     def pull(self, element, key, *, progress=None):
         ref = self.get_artifact_fullname(element, key)