dubbo-serialization-extensions/dubbo-serialization-protobuf/src/main/java/org/apache/dubbo/common/serialize/protobuf/support/GenericProtobufObjectInput.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.dubbo.common.serialize.protobuf.support;

import com.google.protobuf.BoolValue;
import com.google.protobuf.BytesValue;
import com.google.protobuf.DoubleValue;
import com.google.protobuf.FloatValue;
import com.google.protobuf.Int32Value;
import com.google.protobuf.Int64Value;
import com.google.protobuf.StringValue;

import org.apache.dubbo.common.serialize.ObjectInput;
import org.apache.dubbo.common.serialize.protobuf.support.wrapper.MapValue;
import org.apache.dubbo.common.serialize.protobuf.support.wrapper.ThrowablePB;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
import java.util.Map;

import static org.apache.dubbo.common.constants.CommonConstants.HEARTBEAT_EVENT;
import static org.apache.dubbo.common.constants.CommonConstants.MOCK_HEARTBEAT_EVENT;

public class GenericProtobufObjectInput implements ObjectInput {
    private final InputStream is;

    public GenericProtobufObjectInput(InputStream is) {
        this.is = is;
    }

    @Override
    public boolean readBool() throws IOException {
        return read(BoolValue.class).getValue();
    }

    @Override
    public byte readByte() throws IOException {
        return (byte) read(Int32Value.class).getValue();
    }

    @Override
    public short readShort() throws IOException {
        return (short) read(Int32Value.class).getValue();
    }

    @Override
    public int readInt() throws IOException {
        return read(Int32Value.class).getValue();
    }

    @Override
    public long readLong() throws IOException {
        return read(Int64Value.class).getValue();
    }

    @Override
    public float readFloat() throws IOException {
        return read(FloatValue.class).getValue();
    }

    @Override
    public double readDouble() throws IOException {
        return read(DoubleValue.class).getValue();
    }

    @Override
    public String readUTF() throws IOException {
        return read(StringValue.class).getValue();
    }

    @Override
    public byte[] readBytes() throws IOException {
        return read(BytesValue.class).getValue().toByteArray();
    }

    /**
     * Avoid using readObject, always try to pass the target class type for the data you want to read.
     *
     * @return
     */
    @Override
    public Object readObject() {
        throw new UnsupportedOperationException("Provide the protobuf message type you want to read.");
    }

    @Override
    public <T> T readObject(Class<T> cls) throws IOException {
        return read(cls);
    }

    @Override
    public <T> T readObject(Class<T> cls, Type type) throws IOException {
        return readObject(cls);
    }

    @SuppressWarnings("unchecked")
    private <T> T read(Class<T> cls) throws IOException {
        if (!ProtobufUtils.isSupported(cls)) {
            throw new IllegalArgumentException("This serialization only support google protobuf messages, but the actual input type is :" + cls.getName());
        }

        return ProtobufUtils.deserialize(is, cls);
    }

    @Override
    public Throwable readThrowable() throws IOException {
        ThrowablePB.ThrowableProto throwableProto = ProtobufUtils.deserialize(is, ThrowablePB.ThrowableProto.class);
        return ProtobufUtils.convertToException(throwableProto);
    }

    @Override
    public Object readEvent() throws IOException {
        String eventData = readUTF();
        if (eventData.equals(MOCK_HEARTBEAT_EVENT)) {
            eventData = HEARTBEAT_EVENT;
        }
        return eventData;
    }

    @Override
    public Map<String, Object> readAttachments() throws IOException, ClassNotFoundException {
        MapValue.Map map = ProtobufUtils.deserialize(is, MapValue.Map.class);
        return ProtobufAttachmentUtils.unwrap(map);
    }
}