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diff --git a/java/core/src/main/java/com/google/protobuf/BinaryProtocolUtil.java b/java/core/src/main/java/com/google/protobuf/BinaryProtocolUtil.java
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+/** Common methods and constants for the binary protobuf protocol. */
+@ExperimentalApi
+final class BinaryProtocolUtil {
+  private BinaryProtocolUtil() {}
+
+  private static final int TAG_TYPE_BITS = 3;
+  private static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1;
+
+  static final byte WIRETYPE_VARINT = 0;
+  static final byte WIRETYPE_FIXED64 = 1;
+  static final byte WIRETYPE_LENGTH_DELIMITED = 2;
+  static final byte WIRETYPE_START_GROUP = 3;
+  static final byte WIRETYPE_END_GROUP = 4;
+  static final byte WIRETYPE_FIXED32 = 5;
+  static final byte MAX_VARINT32_SIZE = 5;
+  static final byte MAX_VARINT64_SIZE = 10;
+  static final byte FIXED32_SIZE = 4;
+  static final byte FIXED64_SIZE = 8;
+
+  static int tagFor(int fieldNumber, byte wireType) {
+    return (fieldNumber << TAG_TYPE_BITS) | wireType;
+  }
+
+  static int getFieldNumber(final int tag) {
+    return tag >>> TAG_TYPE_BITS;
+  }
+
+  static int getWireType(final int tag) {
+    return tag & TAG_TYPE_MASK;
+  }
+
+  /**
+   * Decode a ZigZag-encoded 32-bit value. ZigZag encodes signed integers into values that can be
+   * efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
+   * to be varint encoded, thus always taking 10 bytes on the wire.)
+   *
+   * @param n An unsigned 32-bit integer, stored in a signed int because Java has no explicit
+   *     unsigned support.
+   * @return A signed 32-bit integer.
+   */
+  static int decodeZigZag32(final int n) {
+    return (n >>> 1) ^ -(n & 1);
+  }
+
+  /**
+   * Decode a ZigZag-encoded 64-bit value. ZigZag encodes signed integers into values that can be
+   * efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
+   * to be varint encoded, thus always taking 10 bytes on the wire.)
+   *
+   * @param n An unsigned 64-bit integer, stored in a signed int because Java has no explicit
+   *     unsigned support.
+   * @return A signed 64-bit integer.
+   */
+  static long decodeZigZag64(final long n) {
+    return (n >>> 1) ^ -(n & 1);
+  }
+
+  /**
+   * Encode a ZigZag-encoded 32-bit value. ZigZag encodes signed integers into values that can be
+   * efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
+   * to be varint encoded, thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 32-bit integer.
+   * @return An unsigned 32-bit integer, stored in a signed int because Java has no explicit
+   *     unsigned support.
+   */
+  static int encodeZigZag32(final int n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 31);
+  }
+
+  /**
+   * Encode a ZigZag-encoded 64-bit value. ZigZag encodes signed integers into values that can be
+   * efficiently encoded with varint. (Otherwise, negative values must be sign-extended to 64 bits
+   * to be varint encoded, thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 64-bit integer.
+   * @return An unsigned 64-bit integer, stored in a signed int because Java has no explicit
+   *     unsigned support.
+   */
+  static long encodeZigZag64(final long n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 63);
+  }
+}