cooker/event: Add an event which lists all stamps reachable after parsing

The metadata can potentially use such an event to clean up any
"unreachable" data, solving several problems we currently have
where obsolete data may continue to exist in the shared areas.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/bb/event.py b/lib/bb/event.py
index fec6a05b3..ba0de11cd 100644
--- a/lib/bb/event.py
+++ b/lib/bb/event.py
@@ -497,6 +497,16 @@ class TargetsTreeGenerated(Event):
         Event.__init__(self)
         self._model = model
 
+class ReachableStamps(Event):
+    """
+    An event listing all stamps reachable after parsing
+    which the metadata may use to clean up stale data
+    """
+
+    def __init__(self, stamps):
+        Event.__init__(self)
+        self.stamps = stamps
+
 class FilesMatchingFound(Event):
     """
     Event when a list of files matching the supplied pattern has