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Diffstat (limited to 'java/core/src/main/java/com/google/protobuf/WireFormat.java')
| -rw-r--r-- | java/core/src/main/java/com/google/protobuf/WireFormat.java | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/java/core/src/main/java/com/google/protobuf/WireFormat.java b/java/core/src/main/java/com/google/protobuf/WireFormat.java new file mode 100644 index 00000000..6a58b081 --- /dev/null +++ b/java/core/src/main/java/com/google/protobuf/WireFormat.java @@ -0,0 +1,256 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 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 +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (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; + +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 WireFormat { + // Do not allow instantiation. + private WireFormat() {} + + public static final int WIRETYPE_VARINT = 0; + public static final int WIRETYPE_FIXED64 = 1; + public static final int WIRETYPE_LENGTH_DELIMITED = 2; + public static final int WIRETYPE_START_GROUP = 3; + public static final int WIRETYPE_END_GROUP = 4; + public 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). */ + public 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; + } + + /** + * Lite equivalent to {@link Descriptors.FieldDescriptor.JavaType}. This is + * only here to support the lite runtime and should not be used by users. + */ + public enum JavaType { + INT(0), + LONG(0L), + FLOAT(0F), + DOUBLE(0D), + BOOLEAN(false), + STRING(""), + BYTE_STRING(ByteString.EMPTY), + ENUM(null), + MESSAGE(null); + + JavaType(final Object defaultDefault) { + this.defaultDefault = defaultDefault; + } + + /** + * The default default value for fields of this type, if it's a primitive + * type. + */ + Object getDefaultDefault() { + return defaultDefault; + } + + private final Object defaultDefault; + } + + /** + * Lite equivalent to {@link Descriptors.FieldDescriptor.Type}. This is + * only here to support the lite runtime and should not be used by users. + */ + public enum FieldType { + DOUBLE (JavaType.DOUBLE , WIRETYPE_FIXED64 ), + FLOAT (JavaType.FLOAT , WIRETYPE_FIXED32 ), + INT64 (JavaType.LONG , WIRETYPE_VARINT ), + UINT64 (JavaType.LONG , WIRETYPE_VARINT ), + INT32 (JavaType.INT , WIRETYPE_VARINT ), + FIXED64 (JavaType.LONG , WIRETYPE_FIXED64 ), + FIXED32 (JavaType.INT , WIRETYPE_FIXED32 ), + BOOL (JavaType.BOOLEAN , WIRETYPE_VARINT ), + STRING (JavaType.STRING , WIRETYPE_LENGTH_DELIMITED) { + @Override + public boolean isPackable() { + return false; } + }, + GROUP (JavaType.MESSAGE , WIRETYPE_START_GROUP ) { + @Override + public boolean isPackable() { + return false; } + }, + MESSAGE (JavaType.MESSAGE , WIRETYPE_LENGTH_DELIMITED) { + @Override + public boolean isPackable() { + return false; } + }, + BYTES (JavaType.BYTE_STRING, WIRETYPE_LENGTH_DELIMITED) { + @Override + public boolean isPackable() { + return false; } + }, + UINT32 (JavaType.INT , WIRETYPE_VARINT ), + ENUM (JavaType.ENUM , WIRETYPE_VARINT ), + SFIXED32(JavaType.INT , WIRETYPE_FIXED32 ), + SFIXED64(JavaType.LONG , WIRETYPE_FIXED64 ), + SINT32 (JavaType.INT , WIRETYPE_VARINT ), + SINT64 (JavaType.LONG , WIRETYPE_VARINT ); + + FieldType(final JavaType javaType, final int wireType) { + this.javaType = javaType; + this.wireType = wireType; + } + + private final JavaType javaType; + private final int wireType; + + public JavaType getJavaType() { return javaType; } + public int getWireType() { return wireType; } + + public boolean isPackable() { return true; } + } + + // Field numbers for fields 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); + + /** + * Validation level for handling incoming string field data which potentially + * contain non-UTF8 bytes. + */ + enum Utf8Validation { + /** Eagerly parses to String; silently accepts invalid UTF8 bytes. */ + LOOSE { + @Override + Object readString(CodedInputStream input) throws IOException { + return input.readString(); + } + }, + /** Eagerly parses to String; throws an IOException on invalid bytes. */ + STRICT { + @Override + Object readString(CodedInputStream input) throws IOException { + return input.readStringRequireUtf8(); + } + }, + /** Keep data as ByteString; validation/conversion to String is lazy. */ + LAZY { + @Override + Object readString(CodedInputStream input) throws IOException { + return input.readBytes(); + } + }; + + /** Read a string field from the input with the proper UTF8 validation. */ + abstract Object readString(CodedInputStream input) throws IOException; + } + + /** + * Read a field of any primitive type for immutable messages from a + * CodedInputStream. Enums, groups, and embedded messages are not handled by + * this method. + * + * @param input The stream from which to read. + * @param type Declared type of the field. + * @param utf8Validation Different string UTF8 validation level for handling + * string fields. + * @return An object representing the field's value, of the exact + * type which would be returned by + * {@link Message#getField(Descriptors.FieldDescriptor)} for + * this field. + */ + static Object readPrimitiveField( + CodedInputStream input, + FieldType type, + Utf8Validation utf8Validation) throws IOException { + switch (type) { + case DOUBLE : return input.readDouble (); + case FLOAT : return input.readFloat (); + case INT64 : return input.readInt64 (); + case UINT64 : return input.readUInt64 (); + case INT32 : return input.readInt32 (); + case FIXED64 : return input.readFixed64 (); + case FIXED32 : return input.readFixed32 (); + case BOOL : return input.readBool (); + case BYTES : return input.readBytes (); + case UINT32 : return input.readUInt32 (); + case SFIXED32: return input.readSFixed32(); + case SFIXED64: return input.readSFixed64(); + case SINT32 : return input.readSInt32 (); + case SINT64 : return input.readSInt64 (); + + case STRING : return utf8Validation.readString(input); + case GROUP: + throw new IllegalArgumentException( + "readPrimitiveField() cannot handle nested groups."); + case MESSAGE: + throw new IllegalArgumentException( + "readPrimitiveField() cannot handle embedded messages."); + case ENUM: + // We don't handle enums because we don't know what to do if the + // value is not recognized. + throw new IllegalArgumentException( + "readPrimitiveField() cannot handle enums."); + } + + throw new RuntimeException( + "There is no way to get here, but the compiler thinks otherwise."); + } +} |