1 files changed, 62 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/skyframe/TaggedEvents.java b/src/main/java/com/google/devtools/build/skyframe/TaggedEvents.java
new file mode 100644
index 0000000000..056175e26d
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/skyframe/TaggedEvents.java
@@ -0,0 +1,62 @@
+// Copyright 2014 Google Inc. 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.skyframe;
+
+import com.google.common.collect.ImmutableCollection;
+import com.google.common.collect.Iterables;
+import com.google.devtools.build.lib.events.Event;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A wrapper of {@link Event} that contains a tag of the label where the event was generated. This
+ * class allows us to tell where the events are coming from when we group all the tags in a
+ * NestedSet.
+ *
+ * <p>The only usage of this code for now is to be able to use --output_filter in Skyframe
+ *
+ * <p>This is intended only for use in alternative {@code MemoizingEvaluator} implementations.
+ */
+@Immutable
+public final class TaggedEvents {
+
+  @Nullable
+  private final String tag;
+  private final ImmutableCollection<Event> events;
+
+  TaggedEvents(@Nullable String tag, ImmutableCollection<Event> events) {
+
+    this.tag = tag;
+    this.events = events;
+  }
+
+  @Nullable
+  String getTag() {
+    return tag;
+  }
+
+  ImmutableCollection<Event> getEvents() {
+    return events;
+  }
+
+  /**
+   * Returns <i>some</i> moderately sane representation of the events. Should never be used in
+   * user-visible places, only for debugging and testing.
+   */
+  @Override
+  public String toString() {
+    return tag == null ? "<unknown>" : tag + ": " + Iterables.toString(events);
+  }
+}