// Protocol Buffers - Google's data interchange format
// Copyright 2013 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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// 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.
//
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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;
}
}