JSONSerializer.java

package org.corfudb.util.serializer;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufInputStream;
import io.netty.buffer.ByteBufOutputStream;
import lombok.extern.slf4j.Slf4j;
import org.corfudb.runtime.CorfuRuntime;
import org.corfudb.runtime.object.ICorfuSMR;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.UUID;

/**
 * Created by mwei on 2/10/16.
 */
@Slf4j
public class JSONSerializer implements ISerializer {
    final private byte type;

    private static final Gson gson = new GsonBuilder()
            .create();

    public JSONSerializer(byte type) {
        this.type = type;
    }

    @Override
    public byte getType() {
        return type;
    }

    /**
     * Deserialize an object from a given byte buffer.
     *
     * @param b The bytebuf to deserialize.
     * @return The deserialized object.
     */
    @Override
    public Object deserialize(ByteBuf b, CorfuRuntime rt) {
        int classNameLength = b.readShort();
        byte[] classNameBytes = new byte[classNameLength];
        b.readBytes(classNameBytes, 0, classNameLength);
        String className = new String(classNameBytes);
        if (className.equals("null")) {
            return null;
        } else if (className.equals("CorfuObject")) {
            int SMRClassNameLength = b.readShort();
            byte[] SMRClassNameBytes = new byte[SMRClassNameLength];
            b.readBytes(SMRClassNameBytes, 0, SMRClassNameLength);
            String SMRClassName = new String(SMRClassNameBytes);
            try {
                return rt.getObjectsView().build()
                        .setStreamID(new UUID(b.readLong(), b.readLong()))
                        .setType(Class.forName(SMRClassName))
                        .open();
            } catch (ClassNotFoundException cnfe) {
                log.error("Exception during deserialization!", cnfe);
                throw new RuntimeException(cnfe);
            }
        } else {
            try (ByteBufInputStream bbis = new ByteBufInputStream(b)) {
                try (InputStreamReader r = new InputStreamReader(bbis)) {
                    return gson.fromJson(r, Class.forName(className));
                }
            } catch (IOException | ClassNotFoundException ie) {
                log.error("Exception during deserialization!", ie);
                throw new RuntimeException(ie);
            }
        }
    }

    /**
     * Serialize an object into a given byte buffer.
     *
     * @param o The object to serialize.
     * @param b The bytebuf to serialize it into.
     */
    @Override
    public void serialize(Object o, ByteBuf b) {
        String className = o == null ? "null" : o.getClass().getName();
        if (className.endsWith(ICorfuSMR.CORFUSMR_SUFFIX)) {
            String SMRClass = className.split("\\$")[0];
            className = "CorfuObject";
            byte[] classNameBytes = className.getBytes();
            b.writeShort(classNameBytes.length);
            b.writeBytes(classNameBytes);
            byte[] SMRClassNameBytes = SMRClass.getBytes();
            b.writeShort(SMRClassNameBytes.length);
            b.writeBytes(SMRClassNameBytes);
            UUID id = ((ICorfuSMR) o).getCorfuStreamID();
            log.trace("Serializing a CorfuObject of type {} as a stream pointer to {}", SMRClass, id);
            b.writeLong(id.getMostSignificantBits());
            b.writeLong(id.getLeastSignificantBits());
        }
        else {
            byte[] classNameBytes = className.getBytes();
            b.writeShort(classNameBytes.length);
            b.writeBytes(classNameBytes);
            if (o == null) {
                return;
            }
            try (ByteBufOutputStream bbos = new ByteBufOutputStream(b)) {
                try (OutputStreamWriter osw = new OutputStreamWriter(bbos)) {
                    gson.toJson(o, o.getClass(), osw);
                }
            } catch (IOException ie) {
                log.error("Exception during serialization!", ie);
            }
        }
    }
}