Removing redundant type conversions for script scoring for hamming space with binary vectors

CHANGELOG.md

@@ -31,6 +31,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add WithFieldName implementation to KNNQueryBuilder (#2398)[https://github.com/opensearch-project/k-NN/pull/2398]
 - Make the build work for M series MacOS without manual code changes and local JAVA_HOME config (#2397)[https://github.com/opensearch-project/k-NN/pull/2397]
 - Remove DocsWithFieldSet reference from NativeEngineFieldVectorsWriter (#2408)[https://github.com/opensearch-project/k-NN/pull/2408]
+- Removing redundant type conversions for script scoring for hamming space with binary vectors (#2351)[https://github.com/opensearch-project/k-NN/pull/2351]
 ### Bug Fixes
 * Fixing the bug when a segment has no vector field present for disk based vector search (#2282)[https://github.com/opensearch-project/k-NN/pull/2282]
 * Fixing the bug where search fails with "fields" parameter for an index with a knn_vector field (#2314)[https://github.com/opensearch-project/k-NN/pull/2314]

src/main/java/org/opensearch/knn/index/KNNVectorDVLeafFieldData.java

@@ -39,7 +39,7 @@ public long ramBytesUsed() {
     }
 
     @Override
-    public ScriptDocValues<float[]> getScriptValues() {
+    public ScriptDocValues<?> getScriptValues() {
         try {
             FieldInfo fieldInfo = FieldInfoExtractor.getFieldInfo(reader, fieldName);
             if (fieldInfo == null) {

src/main/java/org/opensearch/knn/index/KNNVectorScriptDocValues.java

@@ -18,7 +18,7 @@
 import org.opensearch.index.fielddata.ScriptDocValues;
 
 @RequiredArgsConstructor(access = AccessLevel.PRIVATE)
-public abstract class KNNVectorScriptDocValues extends ScriptDocValues<float[]> {
+public abstract class KNNVectorScriptDocValues<T> extends ScriptDocValues<T> {
 
     private final DocIdSetIterator vectorValues;
     private final String fieldName;
@@ -42,7 +42,7 @@ public void setNextDocId(int docId) throws IOException {
         docExists = lastDocID == curDocID;
     }
 
-    public float[] getValue() {
+    public T getValue() {
         if (!docExists) {
             String errorMessage = String.format(
                 "One of the document doesn't have a value for field '%s'. "
@@ -60,15 +60,15 @@ public float[] getValue() {
         }
     }
 
-    protected abstract float[] doGetValue() throws IOException;
+    protected abstract T doGetValue() throws IOException;
 
     @Override
     public int size() {
         return docExists ? 1 : 0;
     }
 
     @Override
-    public float[] get(int i) {
+    public T get(int i) {
         throw new UnsupportedOperationException("knn vector does not support this operation");
     }
 
@@ -81,20 +81,20 @@ public float[] get(int i) {
      * @return A KNNVectorScriptDocValues object based on the type of the values.
      * @throws IllegalArgumentException If the type of values is unsupported.
      */
-    public static KNNVectorScriptDocValues create(DocIdSetIterator values, String fieldName, VectorDataType vectorDataType) {
+    public static KNNVectorScriptDocValues<?> create(DocIdSetIterator values, String fieldName, VectorDataType vectorDataType) {
         Objects.requireNonNull(values, "values must not be null");
         if (values instanceof ByteVectorValues) {
             return new KNNByteVectorScriptDocValues((ByteVectorValues) values, fieldName, vectorDataType);
         } else if (values instanceof FloatVectorValues) {
             return new KNNFloatVectorScriptDocValues((FloatVectorValues) values, fieldName, vectorDataType);
         } else if (values instanceof BinaryDocValues) {
-            return new KNNNativeVectorScriptDocValues((BinaryDocValues) values, fieldName, vectorDataType);
+            return new KNNNativeVectorScriptDocValues<>((BinaryDocValues) values, fieldName, vectorDataType);
         } else {
             throw new IllegalArgumentException("Unsupported values type: " + values.getClass());
         }
     }
 
-    private static final class KNNByteVectorScriptDocValues extends KNNVectorScriptDocValues {
+    private static final class KNNByteVectorScriptDocValues extends KNNVectorScriptDocValues<byte[]> {
         private final ByteVectorValues values;
 
         KNNByteVectorScriptDocValues(ByteVectorValues values, String field, VectorDataType type) {
@@ -103,17 +103,16 @@ private static final class KNNByteVectorScriptDocValues extends KNNVectorScriptD
         }
 
         @Override
-        protected float[] doGetValue() throws IOException {
-            byte[] bytes = values.vectorValue();
-            float[] value = new float[bytes.length];
-            for (int i = 0; i < bytes.length; i++) {
-                value[i] = (float) bytes[i];
+        protected byte[] doGetValue() throws IOException {
+            try {
+                return values.vectorValue();
+            } catch (IOException e) {
+                throw ExceptionsHelper.convertToOpenSearchException(e);
             }
-            return value;
         }
     }
 
-    private static final class KNNFloatVectorScriptDocValues extends KNNVectorScriptDocValues {
+    private static final class KNNFloatVectorScriptDocValues extends KNNVectorScriptDocValues<float[]> {
         private final FloatVectorValues values;
 
         KNNFloatVectorScriptDocValues(FloatVectorValues values, String field, VectorDataType type) {
@@ -127,7 +126,7 @@ protected float[] doGetValue() throws IOException {
         }
     }
 
-    private static final class KNNNativeVectorScriptDocValues extends KNNVectorScriptDocValues {
+    private static final class KNNNativeVectorScriptDocValues<T> extends KNNVectorScriptDocValues<T> {
         private final BinaryDocValues values;
 
         KNNNativeVectorScriptDocValues(BinaryDocValues values, String field, VectorDataType type) {
@@ -136,7 +135,7 @@ private static final class KNNNativeVectorScriptDocValues extends KNNVectorScrip
         }
 
         @Override
-        protected float[] doGetValue() throws IOException {
+        protected T doGetValue() throws IOException {
             return getVectorDataType().getVectorFromBytesRef(values.binaryValue());
         }
     }
@@ -148,10 +147,18 @@ protected float[] doGetValue() throws IOException {
      * @param type      The data type of the vector.
      * @return An empty KNNVectorScriptDocValues object.
      */
-    public static KNNVectorScriptDocValues emptyValues(String fieldName, VectorDataType type) {
-        return new KNNVectorScriptDocValues(DocIdSetIterator.empty(), fieldName, type) {
+    public static KNNVectorScriptDocValues<?> emptyValues(String fieldName, VectorDataType type) {
+        if (type == VectorDataType.FLOAT) {
+            return new KNNVectorScriptDocValues<float[]>(DocIdSetIterator.empty(), fieldName, type) {
+                @Override
+                protected float[] doGetValue() throws IOException {
+                    throw new UnsupportedOperationException("empty values");
+                }
+            };
+        }
+        return new KNNVectorScriptDocValues<byte[]>(DocIdSetIterator.empty(), fieldName, type) {
             @Override
-            protected float[] doGetValue() throws IOException {
+            protected byte[] doGetValue() throws IOException {
                 throw new UnsupportedOperationException("empty values");
             }
         };

src/main/java/org/opensearch/knn/index/VectorDataType.java

@@ -46,15 +46,8 @@ public FieldType createKnnVectorFieldType(int dimension, KNNVectorSimilarityFunc
         }
 
         @Override
-        public float[] getVectorFromBytesRef(BytesRef binaryValue) {
-            float[] vector = new float[binaryValue.length];
-            int i = 0;
-            int j = binaryValue.offset;
-
-            while (i < binaryValue.length) {
-                vector[i++] = binaryValue.bytes[j++];
-            }
-            return vector;
+        public byte[] getVectorFromBytesRef(BytesRef binaryValue) {
+            return binaryValue.bytes;
         }
 
         @Override
@@ -75,15 +68,8 @@ public FieldType createKnnVectorFieldType(int dimension, KNNVectorSimilarityFunc
         }
 
         @Override
-        public float[] getVectorFromBytesRef(BytesRef binaryValue) {
-            float[] vector = new float[binaryValue.length];
-            int i = 0;
-            int j = binaryValue.offset;
-
-            while (i < binaryValue.length) {
-                vector[i++] = binaryValue.bytes[j++];
-            }
-            return vector;
+        public byte[] getVectorFromBytesRef(BytesRef binaryValue) {
+            return binaryValue.bytes;
         }
 
         @Override
@@ -143,7 +129,7 @@ public void freeNativeMemory(long memoryAddress) {
      * @param binaryValue Binary Value
      * @return float vector deserialized from binary value
      */
-    public abstract float[] getVectorFromBytesRef(BytesRef binaryValue);
+    public abstract <T> T getVectorFromBytesRef(BytesRef binaryValue);
 
     /**
      * @param trainingDataAllocation training data that has been allocated in native memory

src/main/java/org/opensearch/knn/plugin/script/KNNScoreScript.java

@@ -114,9 +114,9 @@ public double execute(ScoreScript.ExplanationHolder explanationHolder) {
      * KNNVectors with float[] type. The query value passed in is expected to be float[]. The fieldType of the docs
      * being searched over are expected to be KNNVector type.
      */
-    public static class KNNVectorType extends KNNScoreScript<float[]> {
+    public static class KNNFloatVectorType extends KNNScoreScript<float[]> {
 
-        public KNNVectorType(
+        public KNNFloatVectorType(
             Map<String, Object> params,
             float[] queryValue,
             String field,
@@ -136,8 +136,45 @@ public KNNVectorType(
          * @return score of the vector to the query vector
          */
         @Override
+        @SuppressWarnings("unchecked")
         public double execute(ScoreScript.ExplanationHolder explanationHolder) {
-            KNNVectorScriptDocValues scriptDocValues = (KNNVectorScriptDocValues) getDoc().get(this.field);
+            KNNVectorScriptDocValues<float[]> scriptDocValues = (KNNVectorScriptDocValues<float[]>) getDoc().get(this.field);
+            if (scriptDocValues.isEmpty()) {
+                return 0.0;
+            }
+            return this.scoringMethod.apply(this.queryValue, scriptDocValues.getValue());
+        }
+    }
+
+    /**
+     * KNNVectors with byte[] type. The query value passed in is expected to be byte[]. The fieldType of the docs
+     * being searched over are expected to be KNNVector type.
+     */
+    public static class KNNByteVectorType extends KNNScoreScript<byte[]> {
+
+        public KNNByteVectorType(
+            Map<String, Object> params,
+            byte[] queryValue,
+            String field,
+            BiFunction<byte[], byte[], Float> scoringMethod,
+            SearchLookup lookup,
+            LeafReaderContext leafContext,
+            IndexSearcher searcher
+        ) throws IOException {
+            super(params, queryValue, field, scoringMethod, lookup, leafContext, searcher);
+        }
+
+        /**
+         * This function called for each doc in the segment. We evaluate the score of the vector in the doc
+         *
+         * @param explanationHolder A helper to take in an explanation from a script and turn
+         *                          it into an {@link org.apache.lucene.search.Explanation}
+         * @return score of the vector to the query vector
+         */
+        @Override
+        @SuppressWarnings("unchecked")
+        public double execute(ScoreScript.ExplanationHolder explanationHolder) {
+            KNNVectorScriptDocValues<byte[]> scriptDocValues = (KNNVectorScriptDocValues<byte[]>) getDoc().get(this.field);
             if (scriptDocValues.isEmpty()) {
                 return 0.0;
             }