1 files changed, 33 insertions, 0 deletions
diff --git a/container-search/src/main/java/com/yahoo/search/searchchain/ForkingSearcher.java b/container-search/src/main/java/com/yahoo/search/searchchain/ForkingSearcher.java
new file mode 100644
index 00000000000..cae1ba36e6c
--- /dev/null
+++ b/container-search/src/main/java/com/yahoo/search/searchchain/ForkingSearcher.java
@@ -0,0 +1,33 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.search.searchchain;
+
+import com.yahoo.component.ComponentId;
+import com.yahoo.component.chain.Chain;
+import com.yahoo.search.Searcher;
+
+import java.util.Collection;
+
+/**
+ * Searchers which invokes other search chains should override this.
+ *
+ * @author bratseth
+ */
+public abstract class ForkingSearcher extends Searcher {
+
+    public ForkingSearcher() {}
+
+    /** A search chain with a comment about when it is used. */
+    public static class CommentedSearchChain {
+        public final String comment;
+        public final Chain<Searcher> searchChain;
+
+        public CommentedSearchChain(String comment, Chain<Searcher> searchChain) {
+            this.comment = comment;
+            this.searchChain = searchChain;
+        }
+    }
+
+    /** Returns which searchers this searcher may forward to, for debugging and tracing */
+    public abstract Collection<CommentedSearchChain> getSearchChainsForwarded(SearchChainRegistry registry);
+
+}