--- /dev/null	2019-01-28 17:48:40.000000000 +0800
+++ new/src/share/vm/jfr/writers/jfrWriterHost.hpp	2019-01-28 17:48:40.000000000 +0800
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2016, 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.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_WRITERS_JFRWRITERHOST_HPP
+#define SHARE_VM_JFR_WRITERS_JFRWRITERHOST_HPP
+
+#include "jni.h"
+#include "utilities/globalDefinitions.hpp"
+
+class ClassLoaderData;
+class Klass;
+class Method;
+class Thread;
+
+// BE == Base Encoder
+// IE == Integer Encoder
+template <typename BE, typename IE, typename WriterPolicyImpl >
+class WriterHost : public WriterPolicyImpl {
+ private:
+  const bool _compressed_integers;
+
+  template <typename T>
+  void write_padded(T value);
+  template <typename T>
+  void write_padded(const T* value, size_t len);
+  template <typename T>
+  u1* write_padded(const T* value, size_t len, u1* pos);
+  template <typename T>
+  void write(const T* value, size_t len);
+  template <typename T>
+  u1* write(const T* value, size_t len, u1* pos);
+  void write_utf8(const char* value);
+  void write_utf16(const jchar* value, jint len);
+
+ protected:
+  template <typename T>
+  void be_write(T value);
+  template <typename T>
+  void be_write(const T* value, size_t len);
+  template <typename StorageType>
+  WriterHost(StorageType* storage, Thread* thread);
+  template <typename StorageType>
+  WriterHost(StorageType* storage, size_t size);
+  WriterHost(Thread* thread);
+  u1* ensure_size(size_t requested_size);
+
+ public:
+  template <typename T>
+  void write(T value);
+  void write(bool value);
+  void write(float value);
+  void write(double value);
+  void write(const char* value);
+  void write(char* value);
+  void write(jstring value);
+  void write(const ClassLoaderData* cld);
+  void write(const Klass* klass);
+  void write(const Method* method);
+  void write(const Symbol* symbol);
+  void write(const Ticks& time);
+  void write(const Tickspan& time);
+  void bytes(const void* buf, size_t len);
+  void write_utf8_u2_len(const char* value);
+  template <typename T>
+  void write_padded_at_offset(T value, intptr_t offset);
+  template <typename T>
+  void write_at_offset(T value, intptr_t offset);
+  template <typename T>
+  void write_be_at_offset(T value, intptr_t offset);
+  intptr_t reserve(size_t size);
+};
+
+#endif // SHARE_VM_JFR_WRITERS_JFRWRITERHOST_HPP