Introduce kudo writer.

src/main/java/com/nvidia/spark/rapids/jni/Preconditions.java

@@ -21,7 +21,7 @@
 /**
  * This class contains utility methods for checking preconditions.
  */
-class Preconditions {
+public class Preconditions {
     /**
      * Check if the condition is true, otherwise throw an IllegalStateException with the given message.
      */

src/main/java/com/nvidia/spark/rapids/jni/kudo/DataOutputStreamWriter.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2024, NVIDIA CORPORATION.
+ *
+ * Licensed 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 com.nvidia.spark.rapids.jni.kudo;
+
+import ai.rapids.cudf.HostMemoryBuffer;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+
+/**
+ * Visible for testing
+ */
+class DataOutputStreamWriter extends DataWriter {
+  private final byte[] arrayBuffer = new byte[1024 * 128];
+  private final DataOutputStream dout;
+
+  public DataOutputStreamWriter(DataOutputStream dout) {
+    this.dout = dout;
+  }
+
+  @Override
+  public void writeByte(byte b) throws IOException {
+    dout.writeByte(b);
+  }
+
+  @Override
+  public void writeShort(short s) throws IOException {
+    dout.writeShort(s);
+  }
+
+  @Override
+  public void writeInt(int i) throws IOException {
+    dout.writeInt(i);
+  }
+
+  @Override
+  public void writeIntNativeOrder(int i) throws IOException {
+    // TODO this only works on Little Endian Architectures, x86.  If we need
+    // to support others we need to detect the endianness and switch on the right implementation.
+    writeInt(Integer.reverseBytes(i));
+  }
+
+  @Override
+  public void writeLong(long val) throws IOException {
+    dout.writeLong(val);
+  }
+
+  @Override
+  public void copyDataFrom(HostMemoryBuffer src, long srcOffset, long len) throws IOException {
+    long dataLeft = len;
+    while (dataLeft > 0) {
+      int amountToCopy = (int) Math.min(arrayBuffer.length, dataLeft);
+      src.getBytes(arrayBuffer, 0, srcOffset, amountToCopy);
+      dout.write(arrayBuffer, 0, amountToCopy);
+      srcOffset += amountToCopy;
+      dataLeft -= amountToCopy;
+    }
+  }
+
+  @Override
+  public void flush() throws IOException {
+    dout.flush();
+  }
+
+  @Override
+  public void write(byte[] arr, int offset, int length) throws IOException {
+    dout.write(arr, offset, length);
+  }
+}

src/main/java/com/nvidia/spark/rapids/jni/kudo/DataWriter.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2024, NVIDIA CORPORATION.
+ *
+ * Licensed 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 com.nvidia.spark.rapids.jni.kudo;
+
+import ai.rapids.cudf.HostMemoryBuffer;
+
+import java.io.IOException;
+
+/**
+ * Visible for testing
+ */
+abstract class DataWriter {
+
+  public abstract void writeByte(byte b) throws IOException;
+
+  public abstract void writeShort(short s) throws IOException;
+
+  public abstract void writeInt(int i) throws IOException;
+
+  public abstract void writeIntNativeOrder(int i) throws IOException;
+
+  public abstract void writeLong(long val) throws IOException;
+
+  /**
+   * Copy data from src starting at srcOffset and going for len bytes.
+   *
+   * @param src       where to copy from.
+   * @param srcOffset offset to start at.
+   * @param len       amount to copy.
+   */
+  public abstract void copyDataFrom(HostMemoryBuffer src, long srcOffset, long len) throws IOException;
+
+  public void flush() throws IOException {
+    // NOOP by default
+  }
+
+  public abstract void write(byte[] arr, int offset, int length) throws IOException;
+}