wip: tests succeeding but cache query queue not used yet

2 files changed, 10 insertions, 2 deletions

diff --git a/src/buildstream/_scheduler/__init__.py b/src/buildstream/_scheduler/__init__.py
index d2f458fa5..fcde00dff 100644
--- a/src/buildstream/_scheduler/__init__.py
+++ b/src/buildstream/_scheduler/__init__.py
@@ -25,6 +25,7 @@ from .queues.trackqueue import TrackQueue
 from .queues.buildqueue import BuildQueue
 from .queues.artifactpushqueue import ArtifactPushQueue
 from .queues.pullqueue import PullQueue
+from .queues.cachequeryqueue import CacheQueryQueue
 
 from .scheduler import Scheduler, SchedStatus
 from .jobs import ElementJob, JobStatus
diff --git a/src/buildstream/_stream.py b/src/buildstream/_stream.py
index dc76edad9..f25c2dcd6 100644
--- a/src/buildstream/_stream.py
+++ b/src/buildstream/_stream.py
@@ -38,6 +38,7 @@ from ._scheduler import (
     Scheduler,
     SchedStatus,
     TrackQueue,
+    CacheQueryQueue,
     FetchQueue,
     SourcePushQueue,
     BuildQueue,
@@ -172,8 +173,14 @@ class Stream:
     #    elements (list of Element): The elements to check
     #
     def query_cache(self, elements):
-        # Cache is implicitly queried on demand
-        pass
+        with self._context.messenger.timed_activity("Query cache", silent_nested=True):
+            # Enqueue complete build plan as this is required to determine `buildable` status.
+            plan = self._pipeline.plan(elements)
+
+            self._scheduler.clear_queues()
+            self._add_queue(CacheQueryQueue(self._scheduler))
+            self._enqueue_plan(plan)
+            self._run()
 
     # shell()
     #