fix: adding test ffm comp

java/memory/memory-core/src/test/java/org/apache/arrow/memory/TestFFM.java

@@ -0,0 +1,79 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.arrow.memory;
+
+import java.lang.foreign.MemorySegment;
+import java.nio.ByteBuffer;
+import org.apache.arrow.memory.util.MemoryUtil;
+import org.junit.jupiter.api.Test;
+
+public class TestFFM {
+
+  @Test
+  public void testBufferCopyWithUnsafe() {
+    ByteBuffer srcBuffer = ByteBuffer.allocateDirect(10);
+    ByteBuffer destBuffer = ByteBuffer.allocateDirect(10);
+
+    // Fill source buffer with data
+    for (int i = 0; i < 10; i++) {
+      srcBuffer.put((byte) i);
+    }
+
+    // Flip the buffer to prepare for reading
+    srcBuffer.flip();
+
+    // Get the memory addresses of the buffers
+    long srcAddress = MemoryUtil.getByteBufferAddress(srcBuffer);
+    long destAddress = MemoryUtil.getByteBufferAddress(destBuffer);
+
+    // Copy the data from the source buffer to the destination buffer
+    MemoryUtil.copyMemory(srcAddress, destAddress, 10);
+    // Verify the copy
+    destBuffer.flip();
+    while (destBuffer.hasRemaining()) {
+      System.out.println(destBuffer.get());
+    }
+  }
+
+  @Test
+  public void testBufferCopyWithFFM() {
+    // Allocate two ByteBuffers
+    ByteBuffer srcBuffer = ByteBuffer.allocateDirect(10);
+    ByteBuffer destBuffer = ByteBuffer.allocateDirect(10);
+
+    // Fill source buffer with data
+    for (int i = 0; i < 10; i++) {
+      srcBuffer.put((byte) i);
+    }
+
+    // Flip the source buffer to prepare for reading
+    srcBuffer.flip();
+
+    // Wrap the ByteBuffers with MemorySegments
+    MemorySegment srcSegment = MemorySegment.ofBuffer(srcBuffer);
+    MemorySegment destSegment = MemorySegment.ofBuffer(destBuffer);
+
+    // Copy memory from srcSegment to destSegment
+    srcSegment.copyFrom(destSegment.asSlice(0, 10));
+
+    // Verify the copy
+    destBuffer.flip();
+    while (destBuffer.hasRemaining()) {
+      System.out.println(destBuffer.get());
+    }
+  }
+}