1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // http://code.google.com/p/protobuf/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 package com.google.protobuf; 32 33 /** 34 * This class is used internally by the Protocol Buffer library and generated 35 * message implementations. It is public only because those generated messages 36 * do not reside in the {@code protobuf} package. Others should not use this 37 * class directly. 38 * 39 * This class contains constants and helper functions useful for dealing with 40 * the Protocol Buffer wire format. 41 * 42 * @author kenton (at) google.com Kenton Varda 43 */ 44 public final class WireFormat { 45 // Do not allow instantiation. 46 private WireFormat() {} 47 48 static final int WIRETYPE_VARINT = 0; 49 static final int WIRETYPE_FIXED64 = 1; 50 static final int WIRETYPE_LENGTH_DELIMITED = 2; 51 static final int WIRETYPE_START_GROUP = 3; 52 static final int WIRETYPE_END_GROUP = 4; 53 static final int WIRETYPE_FIXED32 = 5; 54 55 static final int TAG_TYPE_BITS = 3; 56 static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1; 57 58 /** Given a tag value, determines the wire type (the lower 3 bits). */ 59 static int getTagWireType(final int tag) { 60 return tag & TAG_TYPE_MASK; 61 } 62 63 /** Given a tag value, determines the field number (the upper 29 bits). */ 64 public static int getTagFieldNumber(final int tag) { 65 return tag >>> TAG_TYPE_BITS; 66 } 67 68 /** Makes a tag value given a field number and wire type. */ 69 static int makeTag(final int fieldNumber, final int wireType) { 70 return (fieldNumber << TAG_TYPE_BITS) | wireType; 71 } 72 73 /** 74 * Lite equivalent to {@link Descriptors.FieldDescriptor.JavaType}. This is 75 * only here to support the lite runtime and should not be used by users. 76 */ 77 public enum JavaType { 78 INT(0), 79 LONG(0L), 80 FLOAT(0F), 81 DOUBLE(0D), 82 BOOLEAN(false), 83 STRING(""), 84 BYTE_STRING(ByteString.EMPTY), 85 ENUM(null), 86 MESSAGE(null); 87 88 JavaType(final Object defaultDefault) { 89 this.defaultDefault = defaultDefault; 90 } 91 92 /** 93 * The default default value for fields of this type, if it's a primitive 94 * type. 95 */ 96 Object getDefaultDefault() { 97 return defaultDefault; 98 } 99 100 private final Object defaultDefault; 101 } 102 103 /** 104 * Lite equivalent to {@link Descriptors.FieldDescriptor.Type}. This is 105 * only here to support the lite runtime and should not be used by users. 106 */ 107 public enum FieldType { 108 DOUBLE (JavaType.DOUBLE , WIRETYPE_FIXED64 ), 109 FLOAT (JavaType.FLOAT , WIRETYPE_FIXED32 ), 110 INT64 (JavaType.LONG , WIRETYPE_VARINT ), 111 UINT64 (JavaType.LONG , WIRETYPE_VARINT ), 112 INT32 (JavaType.INT , WIRETYPE_VARINT ), 113 FIXED64 (JavaType.LONG , WIRETYPE_FIXED64 ), 114 FIXED32 (JavaType.INT , WIRETYPE_FIXED32 ), 115 BOOL (JavaType.BOOLEAN , WIRETYPE_VARINT ), 116 STRING (JavaType.STRING , WIRETYPE_LENGTH_DELIMITED) { 117 public boolean isPackable() { return false; } 118 }, 119 GROUP (JavaType.MESSAGE , WIRETYPE_START_GROUP ) { 120 public boolean isPackable() { return false; } 121 }, 122 MESSAGE (JavaType.MESSAGE , WIRETYPE_LENGTH_DELIMITED) { 123 public boolean isPackable() { return false; } 124 }, 125 BYTES (JavaType.BYTE_STRING, WIRETYPE_LENGTH_DELIMITED) { 126 public boolean isPackable() { return false; } 127 }, 128 UINT32 (JavaType.INT , WIRETYPE_VARINT ), 129 ENUM (JavaType.ENUM , WIRETYPE_VARINT ), 130 SFIXED32(JavaType.INT , WIRETYPE_FIXED32 ), 131 SFIXED64(JavaType.LONG , WIRETYPE_FIXED64 ), 132 SINT32 (JavaType.INT , WIRETYPE_VARINT ), 133 SINT64 (JavaType.LONG , WIRETYPE_VARINT ); 134 135 FieldType(final JavaType javaType, final int wireType) { 136 this.javaType = javaType; 137 this.wireType = wireType; 138 } 139 140 private final JavaType javaType; 141 private final int wireType; 142 143 public JavaType getJavaType() { return javaType; } 144 public int getWireType() { return wireType; } 145 146 public boolean isPackable() { return true; } 147 } 148 149 // Field numbers for feilds in MessageSet wire format. 150 static final int MESSAGE_SET_ITEM = 1; 151 static final int MESSAGE_SET_TYPE_ID = 2; 152 static final int MESSAGE_SET_MESSAGE = 3; 153 154 // Tag numbers. 155 static final int MESSAGE_SET_ITEM_TAG = 156 makeTag(MESSAGE_SET_ITEM, WIRETYPE_START_GROUP); 157 static final int MESSAGE_SET_ITEM_END_TAG = 158 makeTag(MESSAGE_SET_ITEM, WIRETYPE_END_GROUP); 159 static final int MESSAGE_SET_TYPE_ID_TAG = 160 makeTag(MESSAGE_SET_TYPE_ID, WIRETYPE_VARINT); 161 static final int MESSAGE_SET_MESSAGE_TAG = 162 makeTag(MESSAGE_SET_MESSAGE, WIRETYPE_LENGTH_DELIMITED); 163 } 164
