--- /dev/null	2019-01-28 17:48:24.000000000 +0800
+++ new/src/share/vm/jfr/writers/jfrEncoders.hpp	2019-01-28 17:48:24.000000000 +0800
@@ -0,0 +1,298 @@
+/*
+ * Copyright (c) 2015, 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_JFRENCODERS_HPP
+#define SHARE_VM_JFR_WRITERS_JFRENCODERS_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/bytes.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+//
+// The Encoding policy prescribes a template
+// method taking a first parameter of type T.
+// This is the value to be encoded. The second
+// parameter is a memory address - where to write
+// the encoded value.
+// The encoder method(s) should return the
+// number of bytes encoded into that memory address.
+//
+// template <typename T>
+// size_t encoder(T value, u1* dest);
+//
+// The caller ensures the destination
+// address is not null and that T can be fitted
+// in encoded form.
+//
+
+// Encoding policy classes
+
+class BigEndianEncoderImpl {
+ public:
+  template <typename T>
+  static size_t encode(T value, u1* dest);
+
+  template <typename T>
+  static size_t encode(const T* src, size_t len, u1* dest);
+
+  template <typename T>
+  static size_t encode_padded(T value, u1* dest);
+
+  template <typename T>
+  static size_t encode_padded(const T* src, size_t len, u1* dest);
+
+};
+
+template <typename T>
+inline size_t BigEndianEncoderImpl::encode(T value, u1* dest) {
+  assert(dest != NULL, "invariant");
+  switch (sizeof(T)) {
+    case 1: {
+      ShouldNotReachHere();
+       return 0;
+     }
+     case 2: {
+       Bytes::put_Java_u2(dest, value);
+       return 2;
+     }
+     case 4: {
+       Bytes::put_Java_u4(dest, value);
+       return 4;
+     }
+     case 8: {
+       Bytes::put_Java_u8(dest, value);
+       return 8;
+     }
+  }
+  ShouldNotReachHere();
+  return 0;
+}
+
+template <typename T>
+inline size_t BigEndianEncoderImpl::encode(const T* src, size_t len, u1* dest) {
+  assert(dest != NULL, "invariant");
+  assert(len >= 1, "invariant");
+  if (1 == sizeof(T)) {
+    memcpy(dest, src, len);
+    return len;
+  }
+  size_t size = encode(*src, dest);
+  if (len > 1) {
+    for (size_t i = 1; i < len; ++i) {
+      size += encode(*(src + i), dest + size);
+    }
+  }
+  return size;
+}
+
+template <typename T>
+inline size_t BigEndianEncoderImpl::encode_padded(T value, u1* dest) {
+  return encode(value, dest);
+}
+
+template <typename T>
+inline size_t BigEndianEncoderImpl::encode_padded(const T* src, size_t len, u1* dest) {
+  assert(dest != NULL, "invariant");
+  assert(len >= 1, "invariant");
+  if (1 == sizeof(T)) {
+    memcpy(dest, src, len);
+    return len;
+  }
+  size_t size = encode_padded(*src, dest);
+  if (len > 1) {
+    for (size_t i = 1; i < len; ++i) {
+      size += encode_padded(*(src + i), dest + size);
+    }
+  }
+  return size;
+}
+
+
+// The Varint128 encoder implements encoding according to
+// msb(it) 128bit encoding (1 encode bit | 7 value bits),
+// using least significant byte order.
+//
+// Example (little endian platform):
+// Value: 25674
+// Binary: 00000000 0000000 01100100 01001010
+// Varint encoded (3 bytes):
+// Value: 13289473
+// Varint encoded: 11001010 11001000 00000001
+//
+
+class Varint128EncoderImpl {
+ private:
+  template <typename T>
+  static u8 to_u8(T value);
+
+ public:
+  template <typename T>
+  static size_t encode(T value, u1* dest);
+
+  template <typename T>
+  static size_t encode(const T* src, size_t len, u1* dest);
+
+  template <typename T>
+  static size_t encode_padded(T value, u1* dest);
+
+  template <typename T>
+  static size_t encode_padded(const T* src, size_t len, u1* dest);
+
+};
+
+template <typename T>
+inline u8 Varint128EncoderImpl::to_u8(T value) {
+  switch(sizeof(T)) {
+    case 1:
+     return static_cast<u8>(static_cast<u1>(value) & static_cast<u1>(0xff));
+    case 2:
+      return static_cast<u8>(static_cast<u2>(value) & static_cast<u2>(0xffff));
+    case 4:
+      return static_cast<u8>(static_cast<u4>(value) & static_cast<u4>(0xffffffff));
+    case 8:
+      return static_cast<u8>(value);
+    default:
+      fatal("unsupported type");
+  }
+  return 0;
+}
+
+static const u1 ext_bit = 0x80;
+#define GREATER_THAN_OR_EQUAL_TO_128(v) (((u8)(~(ext_bit - 1)) & (v)))
+#define LESS_THAN_128(v) !GREATER_THAN_OR_EQUAL_TO_128(v)
+
+template <typename T>
+inline size_t Varint128EncoderImpl::encode(T value, u1* dest) {
+  assert(dest != NULL, "invariant");
+
+  const u8 v = to_u8(value);
+
+  if (LESS_THAN_128(v)) {
+    *dest = static_cast<u1>(v); // set bit 0-6, no extension
+    return 1;
+  }
+  *dest = static_cast<u1>(v | ext_bit); // set bit 0-6, with extension
+  if (LESS_THAN_128(v >> 7)) {
+    *(dest + 1) = static_cast<u1>(v >> 7); // set bit 7-13, no extension
+    return 2;
+  }
+  *(dest + 1) = static_cast<u1>((v >> 7) | ext_bit); // set bit 7-13, with extension
+  if (LESS_THAN_128(v >> 14)) {
+    *(dest + 2) = static_cast<u1>(v >> 14); // set bit 14-20, no extension
+    return 3;
+  }
+  *(dest + 2) = static_cast<u1>((v >> 14) | ext_bit); // set bit 14-20, with extension
+  if (LESS_THAN_128(v >> 21)) {
+    *(dest + 3) = static_cast<u1>(v >> 21); // set bit 21-27, no extension
+    return 4;
+  }
+  *(dest + 3) = static_cast<u1>((v >> 21) | ext_bit); // set bit 21-27, with extension
+  if (LESS_THAN_128(v >> 28)) {
+    *(dest + 4) = static_cast<u1>(v >> 28); // set bit 28-34, no extension
+    return 5;
+  }
+  *(dest + 4) = static_cast<u1>((v >> 28) | ext_bit); // set bit 28-34, with extension
+  if (LESS_THAN_128(v >> 35)) {
+    *(dest + 5) = static_cast<u1>(v >> 35); // set bit 35-41, no extension
+    return 6;
+  }
+  *(dest + 5) = static_cast<u1>((v >> 35) | ext_bit); // set bit 35-41, with extension
+  if (LESS_THAN_128(v >> 42)) {
+    *(dest + 6) = static_cast<u1>(v >> 42); // set bit 42-48, no extension
+    return 7;
+  }
+  *(dest + 6) = static_cast<u1>((v >> 42) | ext_bit); // set bit 42-48, with extension
+  if (LESS_THAN_128(v >> 49)) {
+    *(dest + 7) = static_cast<u1>(v >> 49); // set bit 49-55, no extension
+    return 8;
+  }
+  *(dest + 7) = static_cast<u1>((v >> 49) | ext_bit); // set bit 49-55, with extension
+  // no need to extend since only 64 bits allowed.
+  *(dest + 8) = static_cast<u1>(v >> 56);  // set bit 56-63
+  return 9;
+}
+
+template <typename T>
+inline size_t Varint128EncoderImpl::encode(const T* src, size_t len, u1* dest) {
+  assert(dest != NULL, "invariant");
+  assert(len >= 1, "invariant");
+  size_t size = encode(*src, dest);
+  if (len > 1) {
+    for (size_t i = 1; i < len; ++i) {
+      size += encode(*(src + i), dest + size);
+    }
+  }
+  return size;
+}
+
+template <typename T>
+inline size_t Varint128EncoderImpl::encode_padded(T value, u1* dest) {
+  assert(dest != NULL, "invariant");
+  const u8 v = to_u8(value);
+  switch (sizeof(T)) {
+    case 1:
+      dest[0] = static_cast<u1>(v);
+      return 1;
+    case 2:
+      dest[0] = static_cast<u1>(v | 0x80);
+      dest[1] = static_cast<u1>(v >> 7);
+      return 2;
+    case 4:
+      dest[0] = static_cast<u1>(v | 0x80);
+      dest[1] = static_cast<u1>(v >> 7 | 0x80);
+      dest[2] = static_cast<u1>(v >> 14 | 0x80);
+      dest[3] = static_cast<u1>(v >> 21);
+      return 4;
+    case 8:
+      dest[0] = static_cast<u1>(v | 0x80);
+      dest[1] = static_cast<u1>(v >> 7 | 0x80);
+      dest[2] = static_cast<u1>(v >> 14 | 0x80);
+      dest[3] = static_cast<u1>(v >> 21 | 0x80);
+      dest[4] = static_cast<u1>(v >> 28 | 0x80);
+      dest[5] = static_cast<u1>(v >> 35 | 0x80);
+      dest[6] = static_cast<u1>(v >> 42 | 0x80);
+      dest[7] = static_cast<u1>(v >> 49);
+      return 8;
+    default:
+      ShouldNotReachHere();
+    }
+  return 0;
+}
+
+
+template <typename T>
+inline size_t Varint128EncoderImpl::encode_padded(const T* src, size_t len, u1* dest) {
+  assert(dest != NULL, "invariant");
+  assert(len >= 1, "invariant");
+  size_t size = encode_padded(*src, dest);
+  if (len > 1) {
+    for (size_t i = 1; i < len; ++i) {
+      size += encode_padded(*(src + i), dest + size);
+    }
+  }
+  return size;
+}
+
+#endif // SHARE_VM_JFR_WRITERS_JFRENCODERS_HPP