Add interface for extended reporting of events

Not in all situation, having an EventHandler allows detailed enough
reporting on events during the build. Therefore add a new interface
that additionally allows posting arbitrary objects on the event bus.

--
Change-Id: I6ff3eebcad5f36b52c38d3f7ac20df8af2706821
Reviewed-on: https://cr.bazel.build/8793
PiperOrigin-RevId: 148078891
MOS_MIGRATED_REVID=148078891

1 files changed, 28 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/events/ExtendedEventHandler.java b/src/main/java/com/google/devtools/build/lib/events/ExtendedEventHandler.java
new file mode 100644
index 0000000000..42d3abe6b5
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/events/ExtendedEventHandler.java
@@ -0,0 +1,28 @@
+// Copyright 2014 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.events;
+
+/**
+ * Interface for reporting events during the build. It extends the {@link EventHandler} by also
+ * allowing posting arbitrary objects on the event bus.
+ */
+public interface ExtendedEventHandler extends EventHandler {
+
+  /** Interface for declaring events that can be posted via the extended event handler */
+  public interface Postable {}
+
+  /** Report arbitrary information over the evnt bus. */
+  void post(Postable obj);
+}