Add “took” timing info to response for _msearch/template API

Closes #30957

Author: markharwood

modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MultiSearchTemplateResponse.java

@@ -20,12 +20,14 @@
 package org.elasticsearch.script.mustache;
 
 import org.elasticsearch.ElasticsearchException;
+import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionResponse;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Streamable;
+import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.ToXContentObject;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -107,12 +109,14 @@ public Exception getFailure() {
     }
 
     private Item[] items;
-
+    private long tookInMillis; 
+    
     MultiSearchTemplateResponse() {
     }
 
-    public MultiSearchTemplateResponse(Item[] items) {
+    public MultiSearchTemplateResponse(Item[] items, long tookInMillis) {
         this.items = items;
+        this.tookInMillis = tookInMillis;
     }
 
     @Override
@@ -126,6 +130,13 @@ public Iterator<Item> iterator() {
     public Item[] getResponses() {
         return this.items;
     }
+    
+    /**
+     * How long the msearch_template took.
+     */
+    public TimeValue getTook() {
+        return new TimeValue(tookInMillis);
+    }
 
     @Override
     public void readFrom(StreamInput in) throws IOException {
@@ -134,6 +145,9 @@ public void readFrom(StreamInput in) throws IOException {
         for (int i = 0; i < items.length; i++) {
             items[i] = Item.readItem(in);
         }
+        if (in.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            tookInMillis = in.readVLong();
+        }
     }
 
     @Override
@@ -143,11 +157,15 @@ public void writeTo(StreamOutput out) throws IOException {
         for (Item item : items) {
             item.writeTo(out);
         }
+        if (out.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+            out.writeVLong(tookInMillis);
+        }
     }
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, ToXContent.Params params) throws IOException {
         builder.startObject();
+        builder.field("took", tookInMillis);       
         builder.startArray(Fields.RESPONSES);
         for (Item item : items) {
             if (item.isFailure()) {

modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/TransportMultiSearchTemplateAction.java

@@ -94,7 +94,7 @@ protected void doExecute(MultiSearchTemplateRequest request, ActionListener<Mult
                     items[originalSlot].getResponse().setResponse(item.getResponse());
                 }
             }
-            listener.onResponse(new MultiSearchTemplateResponse(items));
+            listener.onResponse(new MultiSearchTemplateResponse(items, r.getTook().millis()));
         }, listener::onFailure));
     }
 }

modules/lang-mustache/src/test/java/org/elasticsearch/script/mustache/MultiSearchTemplateIT.java

@@ -37,6 +37,7 @@
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.arrayWithSize;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.core.Is.is;
 
@@ -140,6 +141,7 @@ public void testBasic() throws Exception {
 
         MultiSearchTemplateResponse response = client().execute(MultiSearchTemplateAction.INSTANCE, multiRequest).get();
         assertThat(response.getResponses(), arrayWithSize(5));
+        assertThat(response.getTook().millis(), greaterThan(0l));
 
         MultiSearchTemplateResponse.Item response1 = response.getResponses()[0];
         assertThat(response1.isFailure(), is(false));