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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
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 [email protected] Kenton Varda
*/
public final class WireFormat {
// Do not allow instantiation.
private WireFormat() {}
static final int FIXED32_SIZE = 4;
static final int FIXED64_SIZE = 8;
static final int MAX_VARINT32_SIZE = 5;
static final int MAX_VARINT64_SIZE = 10;
static final int MAX_VARINT_SIZE = 10;
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.");
}
}