1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 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 import java.io.IOException; 34 35 /** 36 * This class is used internally by the Protocol Buffer library and generated 37 * message implementations. It is public only because those generated messages 38 * do not reside in the {@code protobuf} package. Others should not use this 39 * class directly. 40 * 41 * This class contains constants and helper functions useful for dealing with 42 * the Protocol Buffer wire format. 43 * 44 * @author kenton@google.com Kenton Varda 45 */ 46 public final class WireFormat { 47 // Do not allow instantiation. WireFormat()48 private WireFormat() {} 49 50 public static final int WIRETYPE_VARINT = 0; 51 public static final int WIRETYPE_FIXED64 = 1; 52 public static final int WIRETYPE_LENGTH_DELIMITED = 2; 53 public static final int WIRETYPE_START_GROUP = 3; 54 public static final int WIRETYPE_END_GROUP = 4; 55 public static final int WIRETYPE_FIXED32 = 5; 56 57 static final int TAG_TYPE_BITS = 3; 58 static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1; 59 60 /** Given a tag value, determines the wire type (the lower 3 bits). */ getTagWireType(final int tag)61 public static int getTagWireType(final int tag) { 62 return tag & TAG_TYPE_MASK; 63 } 64 65 /** Given a tag value, determines the field number (the upper 29 bits). */ getTagFieldNumber(final int tag)66 public static int getTagFieldNumber(final int tag) { 67 return tag >>> TAG_TYPE_BITS; 68 } 69 70 /** Makes a tag value given a field number and wire type. */ makeTag(final int fieldNumber, final int wireType)71 static int makeTag(final int fieldNumber, final int wireType) { 72 return (fieldNumber << TAG_TYPE_BITS) | wireType; 73 } 74 75 /** 76 * Lite equivalent to {@link Descriptors.FieldDescriptor.JavaType}. This is 77 * only here to support the lite runtime and should not be used by users. 78 */ 79 public enum JavaType { 80 INT(0), 81 LONG(0L), 82 FLOAT(0F), 83 DOUBLE(0D), 84 BOOLEAN(false), 85 STRING(""), 86 BYTE_STRING(ByteString.EMPTY), 87 ENUM(null), 88 MESSAGE(null); 89 JavaType(final Object defaultDefault)90 JavaType(final Object defaultDefault) { 91 this.defaultDefault = defaultDefault; 92 } 93 94 /** 95 * The default default value for fields of this type, if it's a primitive 96 * type. 97 */ getDefaultDefault()98 Object getDefaultDefault() { 99 return defaultDefault; 100 } 101 102 private final Object defaultDefault; 103 } 104 105 /** 106 * Lite equivalent to {@link Descriptors.FieldDescriptor.Type}. This is 107 * only here to support the lite runtime and should not be used by users. 108 */ 109 public enum FieldType { 110 DOUBLE (JavaType.DOUBLE , WIRETYPE_FIXED64 ), 111 FLOAT (JavaType.FLOAT , WIRETYPE_FIXED32 ), 112 INT64 (JavaType.LONG , WIRETYPE_VARINT ), 113 UINT64 (JavaType.LONG , WIRETYPE_VARINT ), 114 INT32 (JavaType.INT , WIRETYPE_VARINT ), 115 FIXED64 (JavaType.LONG , WIRETYPE_FIXED64 ), 116 FIXED32 (JavaType.INT , WIRETYPE_FIXED32 ), 117 BOOL (JavaType.BOOLEAN , WIRETYPE_VARINT ), STRING(JavaType.STRING , WIRETYPE_LENGTH_DELIMITED)118 STRING (JavaType.STRING , WIRETYPE_LENGTH_DELIMITED) { 119 @Override 120 public boolean isPackable() { 121 return false; } 122 }, GROUP(JavaType.MESSAGE , WIRETYPE_START_GROUP )123 GROUP (JavaType.MESSAGE , WIRETYPE_START_GROUP ) { 124 @Override 125 public boolean isPackable() { 126 return false; } 127 }, MESSAGE(JavaType.MESSAGE , WIRETYPE_LENGTH_DELIMITED)128 MESSAGE (JavaType.MESSAGE , WIRETYPE_LENGTH_DELIMITED) { 129 @Override 130 public boolean isPackable() { 131 return false; } 132 }, BYTES(JavaType.BYTE_STRING, WIRETYPE_LENGTH_DELIMITED)133 BYTES (JavaType.BYTE_STRING, WIRETYPE_LENGTH_DELIMITED) { 134 @Override 135 public boolean isPackable() { 136 return false; } 137 }, 138 UINT32 (JavaType.INT , WIRETYPE_VARINT ), 139 ENUM (JavaType.ENUM , WIRETYPE_VARINT ), 140 SFIXED32(JavaType.INT , WIRETYPE_FIXED32 ), 141 SFIXED64(JavaType.LONG , WIRETYPE_FIXED64 ), 142 SINT32 (JavaType.INT , WIRETYPE_VARINT ), 143 SINT64 (JavaType.LONG , WIRETYPE_VARINT ); 144 FieldType(final JavaType javaType, final int wireType)145 FieldType(final JavaType javaType, final int wireType) { 146 this.javaType = javaType; 147 this.wireType = wireType; 148 } 149 150 private final JavaType javaType; 151 private final int wireType; 152 getJavaType()153 public JavaType getJavaType() { return javaType; } getWireType()154 public int getWireType() { return wireType; } 155 isPackable()156 public boolean isPackable() { return true; } 157 } 158 159 // Field numbers for fields in MessageSet wire format. 160 static final int MESSAGE_SET_ITEM = 1; 161 static final int MESSAGE_SET_TYPE_ID = 2; 162 static final int MESSAGE_SET_MESSAGE = 3; 163 164 // Tag numbers. 165 static final int MESSAGE_SET_ITEM_TAG = 166 makeTag(MESSAGE_SET_ITEM, WIRETYPE_START_GROUP); 167 static final int MESSAGE_SET_ITEM_END_TAG = 168 makeTag(MESSAGE_SET_ITEM, WIRETYPE_END_GROUP); 169 static final int MESSAGE_SET_TYPE_ID_TAG = 170 makeTag(MESSAGE_SET_TYPE_ID, WIRETYPE_VARINT); 171 static final int MESSAGE_SET_MESSAGE_TAG = 172 makeTag(MESSAGE_SET_MESSAGE, WIRETYPE_LENGTH_DELIMITED); 173 174 /** 175 * Validation level for handling incoming string field data which potentially 176 * contain non-UTF8 bytes. 177 */ 178 enum Utf8Validation { 179 /** Eagerly parses to String; silently accepts invalid UTF8 bytes. */ 180 LOOSE { 181 @Override readString(CodedInputStream input)182 Object readString(CodedInputStream input) throws IOException { 183 return input.readString(); 184 } 185 }, 186 /** Eagerly parses to String; throws an IOException on invalid bytes. */ 187 STRICT { 188 @Override readString(CodedInputStream input)189 Object readString(CodedInputStream input) throws IOException { 190 return input.readStringRequireUtf8(); 191 } 192 }, 193 /** Keep data as ByteString; validation/conversion to String is lazy. */ 194 LAZY { 195 @Override readString(CodedInputStream input)196 Object readString(CodedInputStream input) throws IOException { 197 return input.readBytes(); 198 } 199 }; 200 201 /** Read a string field from the input with the proper UTF8 validation. */ readString(CodedInputStream input)202 abstract Object readString(CodedInputStream input) throws IOException; 203 } 204 205 /** 206 * Read a field of any primitive type for immutable messages from a 207 * CodedInputStream. Enums, groups, and embedded messages are not handled by 208 * this method. 209 * 210 * @param input The stream from which to read. 211 * @param type Declared type of the field. 212 * @param utf8Validation Different string UTF8 validation level for handling 213 * string fields. 214 * @return An object representing the field's value, of the exact 215 * type which would be returned by 216 * {@link Message#getField(Descriptors.FieldDescriptor)} for 217 * this field. 218 */ readPrimitiveField( CodedInputStream input, FieldType type, Utf8Validation utf8Validation)219 static Object readPrimitiveField( 220 CodedInputStream input, 221 FieldType type, 222 Utf8Validation utf8Validation) throws IOException { 223 switch (type) { 224 case DOUBLE : return input.readDouble (); 225 case FLOAT : return input.readFloat (); 226 case INT64 : return input.readInt64 (); 227 case UINT64 : return input.readUInt64 (); 228 case INT32 : return input.readInt32 (); 229 case FIXED64 : return input.readFixed64 (); 230 case FIXED32 : return input.readFixed32 (); 231 case BOOL : return input.readBool (); 232 case BYTES : return input.readBytes (); 233 case UINT32 : return input.readUInt32 (); 234 case SFIXED32: return input.readSFixed32(); 235 case SFIXED64: return input.readSFixed64(); 236 case SINT32 : return input.readSInt32 (); 237 case SINT64 : return input.readSInt64 (); 238 239 case STRING : return utf8Validation.readString(input); 240 case GROUP: 241 throw new IllegalArgumentException( 242 "readPrimitiveField() cannot handle nested groups."); 243 case MESSAGE: 244 throw new IllegalArgumentException( 245 "readPrimitiveField() cannot handle embedded messages."); 246 case ENUM: 247 // We don't handle enums because we don't know what to do if the 248 // value is not recognized. 249 throw new IllegalArgumentException( 250 "readPrimitiveField() cannot handle enums."); 251 } 252 253 throw new RuntimeException( 254 "There is no way to get here, but the compiler thinks otherwise."); 255 } 256 } 257