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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.
// http://code.google.com/p/protobuf/
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.protobuf;
/**
* 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 protocol2} 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 WireFormat {
// Do not allow instantiation.
private WireFormat() {}
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(int tag) {
return tag & TAG_TYPE_MASK;
}
/** Given a tag value, determines the field number (the upper 29 bits). */
public static int getTagFieldNumber(int tag) {
return tag >>> TAG_TYPE_BITS;
}
/** Makes a tag value given a field number and wire type. */
static int makeTag(int fieldNumber, int wireType) {
return (fieldNumber << TAG_TYPE_BITS) | wireType;
}
static int getWireFormatForFieldType(Descriptors.FieldDescriptor.Type type) {
switch (type) {
case DOUBLE : return WIRETYPE_FIXED64;
case FLOAT : return WIRETYPE_FIXED32;
case INT64 : return WIRETYPE_VARINT;
case UINT64 : return WIRETYPE_VARINT;
case INT32 : return WIRETYPE_VARINT;
case FIXED64 : return WIRETYPE_FIXED64;
case FIXED32 : return WIRETYPE_FIXED32;
case BOOL : return WIRETYPE_VARINT;
case STRING : return WIRETYPE_LENGTH_DELIMITED;
case GROUP : return WIRETYPE_START_GROUP;
case MESSAGE : return WIRETYPE_LENGTH_DELIMITED;
case BYTES : return WIRETYPE_LENGTH_DELIMITED;
case UINT32 : return WIRETYPE_VARINT;
case ENUM : return WIRETYPE_VARINT;
case SFIXED32: return WIRETYPE_FIXED32;
case SFIXED64: return WIRETYPE_FIXED64;
case SINT32 : return WIRETYPE_VARINT;
case SINT64 : return WIRETYPE_VARINT;
}
throw new RuntimeException(
"There is no way to get here, but the compiler thinks otherwise.");
}
// Field numbers for feilds in MessageSet wire format.
static final int MESSAGE_SET_ITEM = 1;
static final int MESSAGE_SET_TYPE_ID = 2;
static final int MESSAGE_SET_MESSAGE = 3;
// Tag numbers.
static final int MESSAGE_SET_ITEM_TAG =
makeTag(MESSAGE_SET_ITEM, WIRETYPE_START_GROUP);
static final int MESSAGE_SET_ITEM_END_TAG =
makeTag(MESSAGE_SET_ITEM, WIRETYPE_END_GROUP);
static final int MESSAGE_SET_TYPE_ID_TAG =
makeTag(MESSAGE_SET_TYPE_ID, WIRETYPE_VARINT);
static final int MESSAGE_SET_MESSAGE_TAG =
makeTag(MESSAGE_SET_MESSAGE, WIRETYPE_LENGTH_DELIMITED);
}
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