Migrate KNN serialization interfaces

server/src/main/java/org/opensearch/index/knn/codec/KNNVectorSerializer.java

@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.knn.codec;
+
+import org.apache.lucene.util.BytesRef;
+
+/**
+ * Interface abstracts the vector serializer object that is responsible for serialization and de-serialization of k-NN vector
+ */
+public interface KNNVectorSerializer {
+    /**
+     * Serializes array of floats to array of bytes
+     * @param input array that will be converted
+     * @return array of bytes that contains serialized input array
+     */
+    byte[] floatToByteArray(float[] input);
+
+    /**
+     * Deserializes all bytes from the stream to array of floats
+     *
+     * @param bytesRef bytes that will be used for deserialization to array of floats
+     * @return array of floats deserialized from the stream
+     */
+    float[] byteToFloatArray(BytesRef bytesRef);
+}

server/src/main/java/org/opensearch/index/knn/codec/package-info.java

@@ -0,0 +1,10 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+/** Common interfaces for knn codecs to extend. */
+package org.opensearch.index.knn.codec;