- Only call getKey once.

- Just use a presized array of native ints, instead of LinkedList.

2 files changed, 21 insertions, 31 deletions

diff --git a/document/src/main/java/com/yahoo/document/datatypes/Struct.java b/document/src/main/java/com/yahoo/document/datatypes/Struct.java
index bb54b41069b..badcf99b16a 100644
--- a/document/src/main/java/com/yahoo/document/datatypes/Struct.java
+++ b/document/src/main/java/com/yahoo/document/datatypes/Struct.java
@@ -130,12 +130,8 @@ public class Struct extends StructuredFieldValue {
         if (myField==null) {
             throw new IllegalArgumentException("No such field in "+getDataType()+" : "+field.getName());
         }
-        if (!myField
-                   .getDataType().isValueCompatible(value)) {
-            throw new IllegalArgumentException(
-                    "Incompatible data types. Got " + value.getDataType()
-                    + ", expected "
-                    + myField.getDataType());
+        if (!myField.getDataType().isValueCompatible(value)) {
+            throw new IllegalArgumentException("Incompatible data types. Got " + value.getDataType() + ", expected " + myField.getDataType());
         }
 
         if (myField.getId()
@@ -199,10 +195,9 @@ public class Struct extends StructuredFieldValue {
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
-        if (!(o instanceof Struct)) return false;
+        if (!(o instanceof Struct struct)) return false;
         if (!super.equals(o)) return false;
 
-        Struct struct = (Struct) o;
         return values.equals(struct.values);
     }
 
@@ -266,7 +261,7 @@ public class Struct extends StructuredFieldValue {
     }
 
     private class FieldEntry implements Map.Entry<Field, FieldValue> {
-        private int id;
+        private final int id;
 
         private FieldEntry(int id) {
             this.id = id;
@@ -300,9 +295,8 @@ public class Struct extends StructuredFieldValue {
 
         public boolean equals(Object o) {
             if (this == o) return true;
-            if (!(o instanceof FieldEntry)) return false;
+            if (!(o instanceof FieldEntry that)) return false;
 
-            FieldEntry that = (FieldEntry) o;
             return (id == that.id);
         }
 
@@ -327,7 +321,7 @@ public class Struct extends StructuredFieldValue {
 
     private class FieldSetIterator implements Iterator<Map.Entry<Field, FieldValue>> {
         private int position = 0;
-        private int [] increasing = getInOrder();
+        private final int [] increasing = getInOrder();
 
         public boolean hasNext() {
             return (position < increasing.length);
@@ -337,9 +331,7 @@ public class Struct extends StructuredFieldValue {
             if (position >= increasing.length) {
                 throw new NoSuchElementException("No more elements in collection");
             }
-            FieldEntry retval = new FieldEntry(increasing[position]);
-            position++;
-            return retval;
+            return new FieldEntry(increasing[position++]);
         }
 
         public void remove() {
diff --git a/document/src/main/java/com/yahoo/document/serialization/VespaDocumentSerializer6.java b/document/src/main/java/com/yahoo/document/serialization/VespaDocumentSerializer6.java
index 2abaa82d42c..e14d2fea0a2 100644
--- a/document/src/main/java/com/yahoo/document/serialization/VespaDocumentSerializer6.java
+++ b/document/src/main/java/com/yahoo/document/serialization/VespaDocumentSerializer6.java
@@ -60,7 +60,6 @@ import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
@@ -105,8 +104,7 @@ public class VespaDocumentSerializer6 extends BufferSerializer implements Docume
 
         doc.getDataType().serialize(this);
         if (hasHead) {
-            StructuredFieldValue asStructured = doc;
-            write(null, asStructured);
+            write(null, (StructuredFieldValue) doc);
         }
 
         int finalPos = buf.position();
@@ -327,34 +325,35 @@ public class VespaDocumentSerializer6 extends BufferSerializer implements Docume
         GrowableByteBuffer buffer = new GrowableByteBuffer(4096, 2.0f);
         buf = buffer;
 
-        List<Integer> fieldIds = new LinkedList<>();
-        List<java.lang.Integer> fieldLengths = new LinkedList<>();
+        int numFields = s.getFieldCount();
+        int [] fieldIds = new int[numFields];
+        int [] fieldLengths = new int[numFields];
 
         var iter = s.iterator();
-        while (iter.hasNext()) {
+        for (int i=0; iter.hasNext(); i++) {
             Map.Entry<Field, FieldValue> value = iter.next();
 
             int startPos = buffer.position();
-            value.getValue().serialize(value.getKey(), this);
+            Field key = value.getKey();
+            value.getValue().serialize(key, this);
 
-            fieldLengths.add(buffer.position() - startPos);
-            fieldIds.add(value.getKey().getId());
+            fieldLengths[i] = buffer.position() - startPos;
+            fieldIds[i] = key.getId();
         }
 
         // Switch buffers again:
         buffer.flip();
         buf = bigBuffer;
 
-        int sz = fieldIds.size();
         // Actual serialization starts here.
         int lenPos = buf.position();
         putInt(null, 0); // Move back to this after compression is done.
         buf.put(CompressionType.NONE.getCode());
-        buf.putInt1_4Bytes(sz);
+        buf.putInt1_4Bytes(numFields);
 
-        for (int i = 0; i < sz; ++i) {
-            putInt1_4Bytes(null, fieldIds.get(i));
-            putInt2_4_8Bytes(null, fieldLengths.get(i));
+        for (int i = 0; i < numFields; ++i) {
+            putInt1_4Bytes(null, fieldIds[i]);
+            putInt2_4_8Bytes(null, fieldLengths[i]);
         }
 
         int pos = buf.position();
@@ -374,8 +373,7 @@ public class VespaDocumentSerializer6 extends BufferSerializer implements Docume
      * @param value - field value
      */
     public void write(FieldBase field, Struct value) {
-        StructuredFieldValue asStructured = value;
-        write(field, asStructured);
+        write(field, (StructuredFieldValue) value);
     }
 
     /**