wip

1 files changed, 59 insertions, 0 deletions

diff --git a/src/buildstream/_scheduler/queues/cachequeryqueue.py b/src/buildstream/_scheduler/queues/cachequeryqueue.py
new file mode 100644
index 000000000..7ed7dcede
--- /dev/null
+++ b/src/buildstream/_scheduler/queues/cachequeryqueue.py
@@ -0,0 +1,59 @@
+#
+#  Copyright (C) 2020 Bloomberg Finance LP
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+
+from . import Queue, QueueStatus
+from ..resources import ResourceType
+from ..jobs import JobStatus
+from ...types import _KeyStrength
+
+
+# A queue which queries the cache for artifacts and sources
+#
+class CacheQueryQueue(Queue):
+
+    action_name = "Cache-query"
+    complete_name = "Cache queried"
+    resources = [ResourceType.CACHE]
+
+    def get_process_func(self):
+        if self._query_artifacts:
+            return CacheQueryQueue._query_artifacts_or_sources
+        else:
+            return CacheQueryQueue._query_sources
+
+    def status(self, element):
+        if not element._get_cache_key(strength=_KeyStrength.WEAK):
+            # Strict and weak cache keys are unavailable if the element or
+            # a dependency has an unresolved source
+            return QueueStatus.SKIP
+
+        return QueueStatus.READY
+
+    def done(self, _, element, result, status):
+        if status is JobStatus.FAIL:
+            return
+
+        element._cache_query_done()
+
+    @staticmethod
+    def _query_artifacts_or_sources(element):
+        element._query_cache()
+        if not element._can_query_cache() or not element._cached_success():
+            element._query_source_cache()
+
+    @staticmethod
+    def _query_sources(element):
+        element._query_source_cache()