Fix derived source for binary and byte vectors

CHANGELOG.md

@@ -20,6 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Features
 ### Enhancements
 ### Bug Fixes
+*  Fix derived source for binary and byte vectors [#2533](https://github.com/opensearch-project/k-NN/pull/2533/)
 ### Infrastructure
 ### Documentation
 ### Maintenance

src/main/java/org/opensearch/knn/index/codec/derivedsource/AbstractPerFieldDerivedVectorInjector.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.knn.index.codec.derivedsource;
+
+import lombok.extern.log4j.Log4j2;
+import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.util.BytesRef;
+import org.opensearch.knn.common.FieldInfoExtractor;
+import org.opensearch.knn.index.VectorDataType;
+import org.opensearch.knn.index.mapper.KNNVectorFieldMapperUtil;
+import org.opensearch.knn.index.vectorvalues.KNNVectorValues;
+
+import java.io.IOException;
+
+@Log4j2
+abstract class AbstractPerFieldDerivedVectorInjector implements PerFieldDerivedVectorInjector {
+    /**
+     * Utility method for formatting the vector values based on the vector data type. KNNVectorValues must be advanced
+     * to the correct position.
+     *
+     * @param fieldInfo fieldinfo for the vector field
+     * @param vectorValues vector values of the field. getVector or getConditionalVector should return expected vector.
+     * @return vector formatted based on the vector data type
+     * @throws IOException if unable to deserialize stored vector
+     */
+    protected Object formatVector(FieldInfo fieldInfo, KNNVectorValues<?> vectorValues) throws IOException {
+        Object vectorValue = vectorValues.getVector();
+        // If the vector value is a byte[], we must deserialize
+        if (vectorValue instanceof byte[]) {
+            BytesRef vectorBytesRef = new BytesRef((byte[]) vectorValue);
+            VectorDataType vectorDataType = FieldInfoExtractor.extractVectorDataType(fieldInfo);
+            return KNNVectorFieldMapperUtil.deserializeStoredVector(vectorBytesRef, vectorDataType);
+        }
+        return vectorValues.conditionalCloneVector();
+    }
+}

src/main/java/org/opensearch/knn/index/codec/derivedsource/NestedPerFieldDerivedVectorInjector.java

@@ -29,7 +29,7 @@
 
 @Log4j2
 @AllArgsConstructor
-public class NestedPerFieldDerivedVectorInjector implements PerFieldDerivedVectorInjector {
+public class NestedPerFieldDerivedVectorInjector extends AbstractPerFieldDerivedVectorInjector {
 
     private final FieldInfo childFieldInfo;
     private final DerivedSourceReaders derivedSourceReaders;
@@ -116,7 +116,7 @@ public void inject(int parentDocId, Map<String, Object> sourceAsMap) throws IOEx
                 reconstructedSource.add(position, new HashMap<>());
                 positions.add(position, docId);
             }
-            reconstructedSource.get(position).put(childFieldName, vectorValues.conditionalCloneVector());
+            reconstructedSource.get(position).put(childFieldName, formatVector(childFieldInfo, vectorValues));
             offsetPositionsIndex = position + 1;
         }
         sourceAsMap.put(parentFieldName, reconstructedSource);
@@ -137,7 +137,7 @@ private void injectObject(int docId, Map<String, Object> sourceAsMap) throws IOE
             String field = fields[i];
             currentMap = (Map<String, Object>) currentMap.computeIfAbsent(field, k -> new HashMap<>());
         }
-        currentMap.put(fields[fields.length - 1], vectorValues.getVector());
+        currentMap.put(fields[fields.length - 1], formatVector(childFieldInfo, vectorValues));
     }
 
     /**

src/main/java/org/opensearch/knn/index/codec/derivedsource/RootPerFieldDerivedVectorInjector.java

@@ -16,7 +16,7 @@
 /**
  * {@link PerFieldDerivedVectorInjector} for root fields (i.e. non nested fields).
  */
-class RootPerFieldDerivedVectorInjector implements PerFieldDerivedVectorInjector {
+class RootPerFieldDerivedVectorInjector extends AbstractPerFieldDerivedVectorInjector {
 
     private final FieldInfo fieldInfo;
     private final CheckedSupplier<KNNVectorValues<?>, IOException> vectorValuesSupplier;
@@ -40,7 +40,7 @@ public RootPerFieldDerivedVectorInjector(FieldInfo fieldInfo, DerivedSourceReade
     public void inject(int docId, Map<String, Object> sourceAsMap) throws IOException {
         KNNVectorValues<?> vectorValues = vectorValuesSupplier.get();
         if (vectorValues.docId() == docId || vectorValues.advance(docId) == docId) {
-            sourceAsMap.put(fieldInfo.name, vectorValues.conditionalCloneVector());
+            sourceAsMap.put(fieldInfo.name, formatVector(fieldInfo, vectorValues));
         }
     }
 }

src/main/java/org/opensearch/knn/index/mapper/KNNVectorFieldMapperUtil.java

@@ -86,10 +86,10 @@ public static StoredField createStoredFieldForFloatVector(String name, float[] v
      * @return either int[] or float[] of corresponding vector
      */
     public static Object deserializeStoredVector(BytesRef storedVector, VectorDataType vectorDataType) {
-        if (VectorDataType.BYTE == vectorDataType) {
+        if (VectorDataType.BYTE == vectorDataType || VectorDataType.BINARY == vectorDataType) {
             byte[] bytes = storedVector.bytes;
-            int[] byteAsIntArray = new int[bytes.length];
-            Arrays.setAll(byteAsIntArray, i -> bytes[i]);
+            int[] byteAsIntArray = new int[storedVector.length];
+            Arrays.setAll(byteAsIntArray, i -> bytes[i + storedVector.offset]);
             return byteAsIntArray;
         }
 

src/test/java/org/opensearch/knn/index/mapper/KNNVectorFieldMapperUtilTests.java

@@ -41,6 +41,17 @@ public void testStoredFields_whenVectorIsByteType_thenSucceed() {
         assertArrayEquals(byteAsIntArray, (int[]) vector);
     }
 
+    public void testStoredFields_whenVectorIsBinaryType_thenSucceed() {
+        StoredField storedField = KNNVectorFieldMapperUtil.createStoredFieldForByteVector(TEST_FIELD_NAME, TEST_BYTE_VECTOR);
+        assertEquals(TEST_FIELD_NAME, storedField.name());
+        assertEquals(TEST_BYTE_VECTOR, storedField.binaryValue().bytes);
+        Object vector = KNNVectorFieldMapperUtil.deserializeStoredVector(storedField.binaryValue(), VectorDataType.BINARY);
+        assertTrue(vector instanceof int[]);
+        int[] byteAsIntArray = new int[TEST_BYTE_VECTOR.length];
+        Arrays.setAll(byteAsIntArray, i -> TEST_BYTE_VECTOR[i]);
+        assertArrayEquals(byteAsIntArray, (int[]) vector);
+    }
+
     public void testStoredFields_whenVectorIsFloatType_thenSucceed() {
         StoredField storedField = KNNVectorFieldMapperUtil.createStoredFieldForFloatVector(TEST_FIELD_NAME, TEST_FLOAT_VECTOR);
         assertEquals(TEST_FIELD_NAME, storedField.name());