--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.util/src/org/graalvm/util/TypedDataOutputStream.java	Thu Oct 31 16:54:16 2019 -0700
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+
+package org.graalvm.util;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * A stream that can write (trivial) values together with their data type, for use with
+ * {@link TypedDataInputStream}.
+ */
+public class TypedDataOutputStream extends DataOutputStream {
+    /** Determines if {@code value} is supported by {@link #writeTypedValue(Object)}. */
+    public static boolean isValueSupported(Object value) {
+        if (value == null) {
+            return false;
+        }
+        Class<?> valueClass = value.getClass();
+        return valueClass == Boolean.class ||
+                        valueClass == Byte.class ||
+                        valueClass == Short.class ||
+                        valueClass == Character.class ||
+                        valueClass == Integer.class ||
+                        valueClass == Long.class ||
+                        valueClass == Float.class ||
+                        valueClass == Double.class ||
+                        valueClass == String.class ||
+                        value.getClass().isEnum();
+    }
+
+    public TypedDataOutputStream(OutputStream out) {
+        super(out);
+    }
+
+    /**
+     * Writes the value that is represented by the given non-null object, together with information
+     * on the value's data type.
+     *
+     * @param value A value of a {@linkplain #isValueSupported supported type}.
+     * @exception IllegalArgumentException when the provided type is not supported.
+     * @exception IOException in case of an I/O error.
+     */
+    public void writeTypedValue(Object value) throws IOException {
+        Class<?> valueClz = value.getClass();
+        if (valueClz == Boolean.class) {
+            this.writeByte('Z');
+            this.writeBoolean((Boolean) value);
+        } else if (valueClz == Byte.class) {
+            this.writeByte('B');
+            this.writeByte((Byte) value);
+        } else if (valueClz == Short.class) {
+            this.writeByte('S');
+            this.writeShort((Short) value);
+        } else if (valueClz == Character.class) {
+            this.writeByte('C');
+            this.writeChar((Character) value);
+        } else if (valueClz == Integer.class) {
+            this.writeByte('I');
+            this.writeInt((Integer) value);
+        } else if (valueClz == Long.class) {
+            this.writeByte('J');
+            this.writeLong((Long) value);
+        } else if (valueClz == Float.class) {
+            this.writeByte('F');
+            this.writeFloat((Float) value);
+        } else if (valueClz == Double.class) {
+            this.writeByte('D');
+            this.writeDouble((Double) value);
+        } else if (valueClz == String.class) {
+            this.writeByte('U');
+            this.writeUTF((String) value);
+        } else if (valueClz.isEnum()) {
+            this.writeByte('U');
+            this.writeUTF(((Enum<?>) value).name());
+        } else {
+            throw new IllegalArgumentException(String.format("Unsupported type: Value: %s, Value type: %s", value, valueClz));
+        }
+    }
+}