content: // Protocol Buffers - Google's data interchange format
  // Copyright 2013 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
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  // (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.nano;
  
  import java.io.IOException;
  
  /**
   * This class is used internally by the Protocol Buffer library and generated
   * message implementations.  It is public only because those generated messages
   * do not reside in the {@code protobuf} package.  Others should not use this
   * class directly.
   *
   * This class contains constants and helper functions useful for dealing with
   * the Protocol Buffer wire format.
   *
   * @author kenton@google.com Kenton Varda
   */
  public final class WireFormatNano {
    // Do not allow instantiation.
    private WireFormatNano() {}
  
    static final int WIRETYPE_VARINT           = 0;
    static final int WIRETYPE_FIXED64          = 1;
    static final int WIRETYPE_LENGTH_DELIMITED = 2;
    static final int WIRETYPE_START_GROUP      = 3;
    static final int WIRETYPE_END_GROUP        = 4;
    static final int WIRETYPE_FIXED32          = 5;
  
    static final int TAG_TYPE_BITS = 3;
    static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1;
  
    /** Given a tag value, determines the wire type (the lower 3 bits). */
    static int getTagWireType(final int tag) {
      return tag & TAG_TYPE_MASK;
    }
  
    /** Given a tag value, determines the field number (the upper 29 bits). */
    public static int getTagFieldNumber(final int tag) {
      return tag >>> TAG_TYPE_BITS;
    }
  
    /** Makes a tag value given a field number and wire type. */
    static int makeTag(final int fieldNumber, final int wireType) {
      return (fieldNumber << TAG_TYPE_BITS) | wireType;
    }
  
    public static final int EMPTY_INT_ARRAY[] = {};
    public static final long EMPTY_LONG_ARRAY[] = {};
    public static final float EMPTY_FLOAT_ARRAY[] = {};
    public static final double EMPTY_DOUBLE_ARRAY[] = {};
    public static final boolean EMPTY_BOOLEAN_ARRAY[] = {};
    public static final String EMPTY_STRING_ARRAY[] = {};
    public static final byte[] EMPTY_BYTES_ARRAY[] = {};
    public static final byte[] EMPTY_BYTES = {};
  
    /**
     * Parses an unknown field. This implementation skips the field.
     *
     * <p>Generated messages will call this for unknown fields if the store_unknown_fields
     * option is off.
     *
     * @return {@literal true} unless the tag is an end-group tag.
     */
    public static boolean parseUnknownField(
        final CodedInputByteBufferNano input,
        final int tag) throws IOException {
      return input.skipField(tag);
    }
  
    /**
     * Computes the array length of a repeated field. We assume that in the common case repeated
     * fields are contiguously serialized but we still correctly handle interspersed values of a
     * repeated field (but with extra allocations).
     *
     * Rewinds to current input position before returning.
     *
     * @param input stream input, pointing to the byte after the first tag
     * @param tag repeated field tag just read
     * @return length of array
     * @throws IOException
     */
    public static final int getRepeatedFieldArrayLength(
        final CodedInputByteBufferNano input,
        final int tag) throws IOException {
      int arrayLength = 1;
      int startPos = input.getPosition();
      input.skipField(tag);
      while (input.readTag() == tag) {
        input.skipField(tag);
        arrayLength++;
      }
      input.rewindToPosition(startPos);
      return arrayLength;
    }
  
  }
  