Revert "Revert "Bratseth/allocation free hit field traversal""

3 files changed, 49 insertions, 71 deletions

diff --git a/container-search/src/main/java/com/yahoo/search/rendering/DefaultRenderer.java b/container-search/src/main/java/com/yahoo/search/rendering/DefaultRenderer.java
index bae1185d6a9..2d69a262f15 100644
--- a/container-search/src/main/java/com/yahoo/search/rendering/DefaultRenderer.java
+++ b/container-search/src/main/java/com/yahoo/search/rendering/DefaultRenderer.java
@@ -185,28 +185,19 @@ public final class DefaultRenderer extends AsynchronousSectionedRenderer<Result>
 
     private void renderHitFields(XMLWriter writer, Hit hit) {
         renderSyntheticRelevanceField(writer, hit);
-        for (Iterator<Map.Entry<String, Object>> it = hit.fieldIterator(); it.hasNext(); ) {
-            renderField(writer, hit, it);
-        }
-    }
-
-    private void renderField(XMLWriter writer, Hit hit, Iterator<Map.Entry<String, Object>> it) {
-        renderGenericField(writer, hit, it.next());
+        hit.forEachField((name, value) -> renderField(writer, name, value));
     }
 
-    private void renderGenericField(XMLWriter writer, Hit hit, Map.Entry<String, Object> entry) {
-        String fieldName = entry.getKey();
-
-        // skip depending on hit type
-        if (fieldName.startsWith("$")) return; // Don't render fields that start with $ // TODO: Move to should render
+    private void renderField(XMLWriter writer, String name, Object value) {
+        if (name.startsWith("$")) return;
 
-        writeOpenFieldElement(writer, fieldName);
-        renderFieldContent(writer, hit, fieldName);
+        writeOpenFieldElement(writer, name);
+        renderFieldContent(writer, value);
         writeCloseFieldElement(writer);
     }
 
-    private void renderFieldContent(XMLWriter writer, Hit hit, String fieldName) {
-        writer.escapedContent(asXML(hit.getField(fieldName)), false);
+    private void renderFieldContent(XMLWriter writer, Object value) {
+        writer.escapedContent(asXML(value), false);
     }
 
     private String asXML(Object value) {
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 34b02b1bee8..6c7018317c3 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
@@ -14,7 +14,7 @@ import com.yahoo.document.datatypes.FieldValue;
 import com.yahoo.document.datatypes.StringFieldValue;
 import com.yahoo.document.datatypes.TensorFieldValue;
 import com.yahoo.document.json.JsonWriter;
-import com.yahoo.prelude.fastsearch.FastHit;
+import com.yahoo.lang.MutableBoolean;
 import com.yahoo.processing.Response;
 import com.yahoo.processing.execution.Execution.Trace;
 import com.yahoo.processing.rendering.AsynchronousSectionedRenderer;
@@ -49,6 +49,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.io.UncheckedIOException;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.nio.charset.StandardCharsets;
@@ -472,14 +473,14 @@ public class JsonRenderer extends AsynchronousSectionedRenderer<Result> {
         return ! (hit instanceof DefaultErrorHit);
     }
 
-    private boolean fieldsStart(boolean hasFieldsField) throws IOException {
-        if (hasFieldsField) return true;
+    private void fieldsStart(MutableBoolean hasFieldsField) throws IOException {
+        if (hasFieldsField.get()) return;
         generator.writeObjectFieldStart(FIELDS);
-        return true;
+        hasFieldsField.set(true);
     }
 
-    private void fieldsEnd(boolean hasFieldsField) throws IOException {
-        if (!hasFieldsField) return;
+    private void fieldsEnd(MutableBoolean hasFieldsField) throws IOException {
+        if ( ! hasFieldsField.get()) return;
         generator.writeEndObject();
     }
 
@@ -508,39 +509,37 @@ public class JsonRenderer extends AsynchronousSectionedRenderer<Result> {
     }
 
     private void renderAllFields(Hit hit) throws IOException {
-        boolean hasFieldsField = false;
-
-        hasFieldsField |= renderTotalHitCount(hit, hasFieldsField);
-        hasFieldsField |= renderStandardFields(hit, hasFieldsField);
+        MutableBoolean hasFieldsField = new MutableBoolean(false);
+        renderTotalHitCount(hit, hasFieldsField);
+        renderStandardFields(hit, hasFieldsField);
         fieldsEnd(hasFieldsField);
     }
 
-    private boolean renderStandardFields(Hit hit, boolean initialHasFieldsField) throws IOException {
-        boolean hasFieldsField = initialHasFieldsField;
-        for (String fieldName : hit.fieldKeys()) {
-            if (!shouldRender(fieldName, hit)) continue;
-
-            // We can't look at the size of fieldKeys() and know whether we need
-            // the fields object, as all fields may be hidden.
-            hasFieldsField |= fieldsStart(hasFieldsField);
-            renderField(fieldName, hit);
-        }
-        return hasFieldsField;
+    private void renderStandardFields(Hit hit, MutableBoolean hasFieldsField) {
+        hit.forEachField((name, value) -> {
+            try {
+                if (shouldRender(name, value)) {
+                    fieldsStart(hasFieldsField);
+                    renderField(name, value);
+                }
+            }
+            catch (IOException e) {
+                throw new UncheckedIOException(e);
+            }
+        });
     }
 
-    private boolean shouldRender(String fieldName, Hit hit) {
+    private boolean shouldRender(String name, Object value) {
         if (debugRendering) return true;
 
-        if (fieldName.startsWith(VESPA_HIDDEN_FIELD_PREFIX)) return false;
+        if (name.startsWith(VESPA_HIDDEN_FIELD_PREFIX)) return false;
 
-        Object field = hit.getField(fieldName);
-
-        if (field instanceof CharSequence && ((CharSequence) field).length() == 0) return false;
+        if (value instanceof CharSequence && ((CharSequence) value).length() == 0) return false;
 
         // StringFieldValue cannot hold a null, so checking length directly is OK:
-        if (field instanceof StringFieldValue && ((StringFieldValue) field).getString().isEmpty()) return false;
+        if (value instanceof StringFieldValue && ((StringFieldValue) value).getString().isEmpty()) return false;
 
-        if (field instanceof NanNumber) return false;
+        if (value instanceof NanNumber) return false;
 
         return true;
     }
@@ -607,17 +606,16 @@ public class JsonRenderer extends AsynchronousSectionedRenderer<Result> {
         return (id instanceof RawBucketId ? Arrays.toString(((RawBucketId) id).getTo()) : id.getTo()).toString();
     }
 
-    private boolean renderTotalHitCount(Hit hit, boolean hasFieldsField) throws IOException {
-        if ( ! (getRecursionLevel() == 1 && hit instanceof HitGroup)) return false;
+    private void renderTotalHitCount(Hit hit, MutableBoolean hasFieldsField) throws IOException {
+        if ( ! (getRecursionLevel() == 1 && hit instanceof HitGroup)) return;
 
         fieldsStart(hasFieldsField);
         generator.writeNumberField(TOTAL_COUNT, getResult().getTotalHitCount());
-        return true;
     }
 
-    private void renderField(String fieldName, Hit hit) throws IOException {
-        generator.writeFieldName(fieldName);
-        renderFieldContents(hit.getField(fieldName));
+    private void renderField(String name, Object value) throws IOException {
+        generator.writeFieldName(name);
+        renderFieldContents(value);
     }
 
     private void renderFieldContents(Object field) throws IOException {
diff --git a/container-search/src/main/java/com/yahoo/search/rendering/SyncDefaultRenderer.java b/container-search/src/main/java/com/yahoo/search/rendering/SyncDefaultRenderer.java
index dc72061e224..08599540cb1 100644
--- a/container-search/src/main/java/com/yahoo/search/rendering/SyncDefaultRenderer.java
+++ b/container-search/src/main/java/com/yahoo/search/rendering/SyncDefaultRenderer.java
@@ -271,25 +271,19 @@ public final class SyncDefaultRenderer extends Renderer {
 
     private void renderHitFields(XMLWriter writer, Hit hit) {
         renderSyntheticRelevanceField(writer, hit);
-        for (Iterator<Map.Entry<String, Object>> it = hit.fieldIterator(); it.hasNext(); ) {
-            renderField(writer, hit, it);
-        }
+        hit.forEachField((name, value) -> renderField(writer, name, value));
     }
 
-    private void renderField(XMLWriter writer, Hit hit, Iterator<Map.Entry<String, Object>> it) {
-        Map.Entry<String, Object> entry = it.next();
-        String fieldName = entry.getKey();
-
-        if ( ! shouldRenderField(hit, fieldName)) return;
-        if (fieldName.startsWith("$")) return; // Don't render fields that start with $ // TODO: Move to should render
+    private void renderField(XMLWriter writer, String name, Object value) {
+        if (name.startsWith("$")) return;
 
-        writeOpenFieldElement(writer, fieldName);
-        renderFieldContent(writer, hit, fieldName);
+        writeOpenFieldElement(writer, name);
+        renderFieldContent(writer, value);
         writeCloseFieldElement(writer);
     }
 
-    private void renderFieldContent(XMLWriter writer, Hit hit, String fieldName) {
-        writer.escapedContent(asXML(hit.getField(fieldName)), false);
+    private void renderFieldContent(XMLWriter writer, Object value) {
+        writer.escapedContent(asXML(value), false);
     }
 
     private String asXML(Object value) {
@@ -304,10 +298,10 @@ public final class SyncDefaultRenderer extends Renderer {
     }
 
     private void renderSyntheticRelevanceField(XMLWriter writer, Hit hit) {
-        final String relevancyFieldName = "relevancy";
-        final Relevance relevance = hit.getRelevance();
+        String relevancyFieldName = "relevancy";
+        Relevance relevance = hit.getRelevance();
 
-        if (shouldRenderField(hit, relevancyFieldName) && relevance != null) {
+        if (relevance != null) {
             renderSimpleField(writer, relevancyFieldName, relevance);
         }
     }
@@ -332,11 +326,6 @@ public final class SyncDefaultRenderer extends Renderer {
         writer.closeStartTag();
     }
 
-    private boolean shouldRenderField(Hit hit, String relevancyFieldName) {
-        // skip depending on hit type
-        return true;
-    }
-
     private void renderHitAttributes(XMLWriter writer, Hit hit) {
         writer.attribute(TYPE, hit.types().stream().collect(Collectors.joining(" ")));
         if (hit.getRelevance() != null) {