render maps with string keys as JSON objects

* if structured data is an array of <key,value> objects,
  we prefer to render it as a JSON object since it is most
  likely a map in the document definition.
* makes docsum rendering a closer match with document rendering
  and feed input format.

2 files changed, 90 insertions, 4 deletions

diff --git a/container-search/src/main/java/com/yahoo/search/rendering/JsonRenderer.java b/container-search/src/main/java/com/yahoo/search/rendering/JsonRenderer.java
index 55c846ccb5b..f8750e984a6 100644
--- a/container-search/src/main/java/com/yahoo/search/rendering/JsonRenderer.java
+++ b/container-search/src/main/java/com/yahoo/search/rendering/JsonRenderer.java
@@ -9,6 +9,8 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Preconditions;
 import com.yahoo.data.JsonProducer;
 import com.yahoo.data.access.Inspectable;
+import com.yahoo.data.access.Inspector;
+import com.yahoo.data.access.Type;
 import com.yahoo.data.access.simple.JsonRender;
 import com.yahoo.document.datatypes.FieldValue;
 import com.yahoo.document.datatypes.StringFieldValue;
@@ -45,6 +47,7 @@ import com.yahoo.yolean.trace.TraceVisitor;
 import org.json.JSONArray;
 import org.json.JSONObject;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintWriter;
@@ -313,6 +316,32 @@ public class JsonRenderer extends AsynchronousSectionedRenderer<Result> {
         generator.writeFieldName(ROOT);
     }
 
+    public String renderAsMap(Inspector data) throws IOException {
+        if (data.type() != Type.ARRAY) return null;
+        if (data.entryCount() == 0) return null;
+        ByteArrayOutputStream subStream = new ByteArrayOutputStream();
+        JsonGenerator subGenerator = generatorFactory.createGenerator(subStream, JsonEncoding.UTF8);
+        subGenerator.writeStartObject();
+        for (int i = 0; i < data.entryCount(); i++) {
+            Inspector obj = data.entry(i);
+            if (obj.type() != Type.OBJECT) return null;
+            if (obj.fieldCount() != 2) return null;
+            Inspector keyObj = obj.field("key");
+            if (keyObj.type() != Type.STRING) return null;
+
+            subGenerator.writeFieldName(keyObj.asString());
+
+            Inspector valueObj = obj.field("value");
+            if (! valueObj.valid()) return null;
+            StringBuilder intermediate = new StringBuilder();
+            JsonRender.render(valueObj, intermediate, true);
+            subGenerator.writeRawValue(intermediate.toString());
+        }
+        subGenerator.writeEndObject();
+        subGenerator.close();
+        return subStream.toString("UTF-8");
+    }
+
     private void renderTiming() throws IOException {
         if (!getResult().getQuery().getPresentation().getTiming()) return;
 
@@ -662,7 +691,7 @@ public class JsonRenderer extends AsynchronousSectionedRenderer<Result> {
      * This instance is reused for all hits of a Result since we are in a single-threaded context
      * and want to limit object creation.
      */
-    private static class FieldConsumer implements Hit.RawUtf8Consumer {
+    private class FieldConsumer implements Hit.RawUtf8Consumer {
 
         private final JsonGenerator generator;
         private final boolean debugRendering;
@@ -741,6 +770,17 @@ public class JsonRenderer extends AsynchronousSectionedRenderer<Result> {
             return true;
         }
 
+        private void renderInspector(Inspector data) throws IOException {
+            String asMap = renderAsMap(data);
+            if (asMap != null) {
+                generator.writeRawValue(asMap);
+            } else {
+                StringBuilder intermediate = new StringBuilder();
+                JsonRender.render(data, intermediate, true);
+                generator.writeRawValue(intermediate.toString());
+            }
+        }
+
         private void renderFieldContents(Object field) throws IOException {
             if (field == null) {
                 generator.writeNull();
@@ -753,9 +793,7 @@ public class JsonRenderer extends AsynchronousSectionedRenderer<Result> {
             } else if (field instanceof JsonProducer) {
                 generator.writeRawValue(((JsonProducer) field).toJson());
             } else if (field instanceof Inspectable) {
-                StringBuilder intermediate = new StringBuilder();
-                JsonRender.render((Inspectable) field, intermediate, true);
-                generator.writeRawValue(intermediate.toString());
+                renderInspector(((Inspectable)field).inspect());
             } else if (field instanceof StringFieldValue) {
                 generator.writeString(((StringFieldValue)field).getString());
             } else if (field instanceof TensorFieldValue) {
diff --git a/container-search/src/test/java/com/yahoo/search/rendering/JsonRendererTestCase.java b/container-search/src/test/java/com/yahoo/search/rendering/JsonRendererTestCase.java
index bf56ad19f44..caad1c76362 100644
--- a/container-search/src/test/java/com/yahoo/search/rendering/JsonRendererTestCase.java
+++ b/container-search/src/test/java/com/yahoo/search/rendering/JsonRendererTestCase.java
@@ -9,6 +9,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.yahoo.component.chain.Chain;
+import com.yahoo.data.access.simple.Value;
 import com.yahoo.data.access.slime.SlimeAdapter;
 import com.yahoo.document.DataType;
 import com.yahoo.document.DocumentId;
@@ -1111,6 +1112,53 @@ public class JsonRendererTestCase {
     }
 
     @Test
+    public final void testMapInField() throws IOException, InterruptedException, ExecutionException, JSONException {
+        String expected = "{\n"
+                + "    \"root\": {\n"
+                + "        \"children\": [\n"
+                + "            {\n"
+                + "                \"fields\": {\n"
+                + "                    \"structured\": {\n"
+                + "                        \"foo\": \"string foo\",\n"
+                + "                        \"bar\": [\"array bar elem 1\", \"array bar elem 2\"],\n"
+                + "                        \"baz\": {\"f1\": \"object baz field 1\", \"f2\": \"object baz field 2\"}\n"
+                + "                    }\n"
+                + "                },\n"
+                + "                \"id\": \"MapInField\",\n"
+                + "                \"relevance\": 1.0\n"
+                + "            }\n"
+                + "        ],\n"
+                + "        \"fields\": {\n"
+                + "            \"totalCount\": 1\n"
+                + "        },\n"
+                + "        \"id\": \"toplevel\",\n"
+                + "        \"relevance\": 1.0\n"
+                + "    }\n"
+                + "}\n";
+        Result r = newEmptyResult();
+        Hit h = new Hit("MapInField");
+        Value.ArrayValue atop = new Value.ArrayValue();
+        atop.add(new Value.ObjectValue()
+                 .put("key", new Value.StringValue("foo"))
+                 .put("value", new Value.StringValue("string foo")))
+            .add(new Value.ObjectValue()
+                 .put("key", new Value.StringValue("bar"))
+                 .put("value", new Value.ArrayValue()
+                      .add(new Value.StringValue("array bar elem 1"))
+                      .add(new Value.StringValue("array bar elem 2"))))
+            .add(new Value.ObjectValue()
+                 .put("key", new Value.StringValue("baz"))
+                 .put("value", new Value.ObjectValue()
+                      .put("f1", new Value.StringValue("object baz field 1"))
+                      .put("f2", new Value.StringValue("object baz field 2"))));
+        h.setField("structured", atop);
+        r.hits().add(h);
+        r.setTotalHitCount(1L);
+        String summary = render(r);
+        assertEqualJson(expected, summary);
+    }
+
+    @Test
     public void testThatTheJsonValidatorCanCatchErrors() {
         String json = "{"
                 + "    \"root\": {"