Ignite序列化及反序列化 BinaryMarshaller 源码分析

实现接口

public interface Marshaller {
    /**
     * Sets marshaller context.
     *
     * @param ctx Marshaller context.
     */
    public void setContext(MarshallerContext ctx);

    /**
     * Marshals object to the output stream. This method should not close
     * given output stream.
     *
     * @param obj Object to marshal.
     * @param out Output stream to marshal into.
     * @throws IgniteCheckedException If marshalling failed.
     */
    public void marshal(@Nullable Object obj, OutputStream out) throws IgniteCheckedException;

    /**
     * Marshals object to byte array.
     *
     * @param obj Object to marshal.
     * @return Byte array.
     * @throws IgniteCheckedException If marshalling failed.
     */
    public byte[] marshal(@Nullable Object obj) throws IgniteCheckedException;

    /**
     * Unmarshals object from the input stream using given class loader.
     * This method should not close given input stream.
     *
     * @param  Type of unmarshalled object.
     * @param in Input stream.
     * @param clsLdr Class loader to use.
     * @return Unmarshalled object.
     * @throws IgniteCheckedException If unmarshalling failed.
     */
    public  T unmarshal(InputStream in, @Nullable ClassLoader clsLdr) throws IgniteCheckedException;

    /**
     * Unmarshals object from byte array using given class loader.
     *
     * @param  Type of unmarshalled object.
     * @param arr Byte array.
     * @param clsLdr Class loader to use.
     * @return Unmarshalled object.
     * @throws IgniteCheckedException If unmarshalling failed.
     */
    public  T unmarshal(byte[] arr, @Nullable ClassLoader clsLdr) throws IgniteCheckedException;
}

最终实现是调用 org.apache.ignite.internal.binary.GridBinaryMarshaller中的方法

序列化方法

/**
     * @param obj Object to marshal.
     * @param failIfUnregistered Throw exception if class isn't registered.
     * @return Byte array.
     * @throws org.apache.ignite.binary.BinaryObjectException In case of error.
     */
    public byte[] marshal(@Nullable Object obj, boolean failIfUnregistered) throws BinaryObjectException {
        if (obj == null)
            return new byte[] { NULL };

        try (BinaryWriterExImpl writer = new BinaryWriterExImpl(ctx)) {
            writer.failIfUnregistered(failIfUnregistered);

            writer.marshal(obj);

            return writer.array();
        }
    }

反序列化

/**
     * @param arr Byte array.
     * @param ldr Class loader.
     * @return Deserialized object.
     * @throws org.apache.ignite.binary.BinaryObjectException In case of error.
     */
    @SuppressWarnings("unchecked")
    @Nullable public  T deserialize(byte[] arr, @Nullable ClassLoader ldr) throws BinaryObjectException {
        assert arr != null;
        assert arr.length > 0;

        if (arr[0] == NULL)
            return null;

        BinaryContext oldCtx = pushContext(ctx);

        try {
            return (T)new BinaryReaderExImpl(ctx, BinaryHeapInputStream.create(arr, 0), ldr, true).deserialize();
        }
        finally {
            popContext(oldCtx);
        }
    }

这里面引入2个类 BinaryWriterExImpl, BinaryReaderExImpl

往里面走

GridBinaryMarshaller.deserialize
(T)new BinaryReaderExImpl(ctx, BinaryHeapInputStream.create(arr, 0), ldr, true).deserialize()

case OPTM_MARSH:
 obj = BinaryUtils.doReadOptimized(in, ctx, ldr);

ctx.optimizedMarsh().unmarshal(input, U.resolveClassLoader(clsLdr, ctx.configuration())) -> unmarshal0


ctx.optiomizedMarsh() = OptimizedMarshaller

return (T)objIn.readObject();

objIn = OptimizedObjectInputStream -> readObject0() -> case HANDLE:
 return handles.lookup(readInt());

OptimizedObjectInputStream

这段代码比较特殊
case HANDLE:
 return handles.lookup(readInt());
handles = HandleTable

是handle类型的,直接取数据
这个handle类型的意思是, 如果是使用优化方式的序列化, 在遇到相同字符的时候,只会记录一个数字,而不需要把整个字符都重复记录一遍, 这样大大节省了空间, 这要求读跟写都遵循这套方法, 才能正确解出数据

TcpDiscoveryNode [id=8164f1e1-ff3f-4d6f-bdc5-d9615339d292, addrs=[0:0:0:0:0:0:0:1, 127.0.0.1, 192.168.120.80], sockAddrs=[WLPF15J9DQ.wks.jnj.com/192.168.120.80:47501, /0:0:0:0:0:0:0:1:47501, /127.0.0.1:47501], discPort=47501, order=2, intOrder=2, lastExchangeTime=1555666131881, loc=false, ver=2.7.0#20181201-sha1:256ae401, isClient=false]

下面分析一下序列化

OptimizedObjectOutputStream.writeObject0

待续