CR: Add separate context for scriptheuristic

Author: original-brownbear

server/src/main/java/org/elasticsearch/script/ScriptHeuristicScript.java

@@ -0,0 +1,38 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you 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 org.elasticsearch.script;
+
+import java.util.Map;
+
+/**
+ * A script used in script heuristics.
+ */
+public abstract class ScriptHeuristicScript {
+
+    public static final String[] PARAMETERS = { "params" };
+
+    public static final ScriptContext<Factory> CONTEXT = new ScriptContext<>("script_heuristic", Factory.class);
+
+    public abstract double execute(Map<String, Object> params);
+
+    public interface Factory {
+        ScriptHeuristicScript newInstance();
+    }
+}

server/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ScriptHeuristic.java

@@ -28,8 +28,8 @@
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.query.QueryShardException;
-import org.elasticsearch.script.BucketAggregationScript;
 import org.elasticsearch.script.Script;
+import org.elasticsearch.script.ScriptHeuristicScript;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.internal.SearchContext;
 
@@ -50,10 +50,10 @@ static class ExecutableScriptHeuristic extends ScriptHeuristic {
         private final LongAccessor supersetSizeHolder;
         private final LongAccessor subsetDfHolder;
         private final LongAccessor supersetDfHolder;
-        private final BucketAggregationScript executableScript;
+        private final ScriptHeuristicScript executableScript;
         private final Map<String, Object> params = new HashMap<>();
 
-        ExecutableScriptHeuristic(Script script, BucketAggregationScript executableScript) {
+        ExecutableScriptHeuristic(Script script, ScriptHeuristicScript executableScript) {
             super(script);
             subsetSizeHolder = new LongAccessor();
             supersetSizeHolder = new LongAccessor();
@@ -95,14 +95,14 @@ public void writeTo(StreamOutput out) throws IOException {
 
     @Override
     public SignificanceHeuristic rewrite(InternalAggregation.ReduceContext context) {
-        BucketAggregationScript.Factory factory = context.scriptService().compile(script, BucketAggregationScript.CONTEXT);
+        ScriptHeuristicScript.Factory factory = context.scriptService().compile(script, ScriptHeuristicScript.CONTEXT);
         return new ExecutableScriptHeuristic(script, factory.newInstance());
     }
 
     @Override
     public SignificanceHeuristic rewrite(SearchContext context) {
         QueryShardContext shardContext = context.getQueryShardContext();
-        BucketAggregationScript.Factory compiledScript = shardContext.getScriptService().compile(script, BucketAggregationScript.CONTEXT);
+        ScriptHeuristicScript.Factory compiledScript = shardContext.getScriptService().compile(script, ScriptHeuristicScript.CONTEXT);
         return new ExecutableScriptHeuristic(script, compiledScript.newInstance());
     }