Add a float array to byte array utility method (#3374)

* Add a float array to byte array utility method

* test

src/main/java/redis/clients/jedis/search/RediSearchUtil.java

@@ -1,11 +1,22 @@
 package redis.clients.jedis.search;
 
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
 import java.util.HashMap;
 import java.util.Map;
+
 import redis.clients.jedis.util.SafeEncoder;
 
 public class RediSearchUtil {
 
+  /**
+   * Jedis' {@code hset} methods do not support {@link Object}s as values. This method eases process
+   * of converting a {@link Map} with Objects as values so that the returning Map can be set to a
+   * {@code hset} method.
+   * @param input map with object value
+   * @return map with string value
+   */
   public static Map<String, String> toStringMap(Map<String, Object> input) {
     Map<String, String> output = new HashMap<>(input.size());
     for (Map.Entry<String, Object> entry : input.entrySet()) {
@@ -30,6 +41,19 @@ public static Map<String, String> toStringMap(Map<String, Object> input) {
     return output;
   }
 
+  /**
+   * x86 systems are little-endian and Java defaults to big-endian. This causes mismatching query
+   * results when RediSearch is running in a x86 system. This method helps to convert concerned
+   * arrays.
+   * @param input float array
+   * @return byte array
+   */
+  public static byte[] ToByteArray(float[] input) {
+    byte[] bytes = new byte[Float.BYTES * input.length];
+    ByteBuffer.wrap(bytes).order(ByteOrder.LITTLE_ENDIAN).asFloatBuffer().put(input);
+    return bytes;
+  }
+
   private RediSearchUtil() {
     throw new InstantiationError("Must not instantiate this class");
   }

src/test/java/redis/clients/jedis/modules/search/SearchConfigTest.java

@@ -2,13 +2,13 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.fail;
 
 import java.util.Collections;
 import java.util.Map;
+
 import org.junit.BeforeClass;
 import org.junit.Test;
-import redis.clients.jedis.exceptions.JedisDataException;
+
 import redis.clients.jedis.modules.RedisModuleCommandsTestBase;
 
 public class SearchConfigTest extends RedisModuleCommandsTestBase {

src/test/java/redis/clients/jedis/modules/search/UtilTest.java

@@ -0,0 +1,16 @@
+package redis.clients.jedis.modules.search;
+
+import org.junit.Assert;
+import org.junit.Test;
+import redis.clients.jedis.search.RediSearchUtil;
+
+public class UtilTest {
+
+  @Test
+  public void floatArrayToByteArray() {
+    float[] floats = new float[]{0.2f};
+    byte[] bytes = RediSearchUtil.ToByteArray(floats);
+    byte[] expected = new byte[]{-51, -52, 76, 62};
+    Assert.assertArrayEquals(expected, bytes);
+  }
+}