1 files changed, 62 insertions, 0 deletions
diff --git a/src/buildstream/_scheduler/queues/trackqueue.py b/src/buildstream/_scheduler/queues/trackqueue.py
new file mode 100644
index 000000000..72a79a532
--- /dev/null
+++ b/src/buildstream/_scheduler/queues/trackqueue.py
@@ -0,0 +1,62 @@
+#
+#  Copyright (C) 2016 Codethink Limited
+#
+#  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/>.
+#
+#  Authors:
+#        Tristan Van Berkom <tristan.vanberkom@codethink.co.uk>
+#        Jürg Billeter <juerg.billeter@codethink.co.uk>
+
+# BuildStream toplevel imports
+from ...plugin import Plugin
+
+# Local imports
+from . import Queue, QueueStatus
+from ..resources import ResourceType
+from ..jobs import JobStatus
+
+
+# A queue which tracks sources
+#
+class TrackQueue(Queue):
+
+    action_name = "Track"
+    complete_name = "Tracked"
+    resources = [ResourceType.DOWNLOAD]
+
+    def process(self, element):
+        return element._track()
+
+    def status(self, element):
+        # We can skip elements entirely if they have no sources.
+        if not list(element.sources()):
+
+            # But we still have to mark them as tracked
+            element._tracking_done()
+            return QueueStatus.SKIP
+
+        return QueueStatus.READY
+
+    def done(self, _, element, result, status):
+
+        if status == JobStatus.FAIL:
+            return
+
+        # Set the new refs in the main process one by one as they complete,
+        # writing to bst files this time
+        for unique_id, new_ref in result:
+            source = Plugin._lookup(unique_id)
+            source._set_ref(new_ref, save=True)
+
+        element._tracking_done()