hsf笔记-InvocationHandler

InvocationHandler使用责任链的方式来调用,总体思路就是一(出口)带多(拦截器)

1.InvocationHandlerChainFactory

InvocationHandlerChainFactory用于构建InvocationHandler链路

public interface InvocationHandlerInterceptor extends InvocationHandler {
    void setInvocationHandler(InvocationHandler var1);
}

public class InvocationHandlerChainFactory {
    public InvocationHandlerChainFactory() {
    }

    public static InvocationHandler buildHandlerChain(ServiceMetadata metadata, InvocationHandler invocationHandler) {
        List handlers;
        if (metadata.isProvider()) {
            handlers = HSFServiceContainer.getInstances(InvocationHandlerInterceptor.class, new String[]{"server"});
        } else {
            handlers = HSFServiceContainer.getInstances(InvocationHandlerInterceptor.class, new String[]{"client"});
        }

        InvocationHandler last = invocationHandler;

        for(int i = handlers.size() - 1; i >= 0; --i) {
            InvocationHandlerInterceptor handler = (InvocationHandlerInterceptor)handlers.get(i);
            handler.setInvocationHandler((InvocationHandler)last);
            if (handler instanceof ServiceMetadataAware) {
                ((ServiceMetadataAware)handler).setServiceMetadata(metadata);
            }

            if (handler instanceof LifeCycle) {
                ((LifeCycle)handler).start();
            }

            last = handler;
        }

        return (InvocationHandler)last;
    }
}

以Consumer为例,获取到6个InvocationHandler

转换成责任链模式

2.InvocationHandler

2.1 DubboAsyncInvocationHandler

根据InvokeMode类型执行,这里是同步则直接掉到下个InvocationHandler

    public ListenableFuture invoke(Invocation invocation) throws Throwable {
        InvokeMode invokeType = invocation.getInvokeType();
        ListenableFuture rpcFuture;
        if (InvokeMode.FUTURE == invokeType) {
            rpcFuture = this.delegate.invoke(invocation);
            this.futureInvoke(invocation, rpcFuture);
        } else if (InvokeMode.CALLBACK == invokeType) {
            rpcFuture = callbackInvoke(invocation, this.delegate, this.threadPoolService.callbackExecutor());
        } else {
            rpcFuture = this.delegate.invoke(invocation);
        }

        return rpcFuture;
    }

2.2 FutureInvocationHandler

将UserThreadPreferedExecutor设置为Invocation的executor属性

    public ListenableFuture invoke(Invocation invocation) throws Throwable {
        InvokeMode invokeType = invocation.getInvokeType();
        if (InvokeMode.SYNC == invokeType) {
            UserThreadPreferedExecutor userThreadPreferedExecutor = new UserThreadPreferedExecutor(this.threadPoolService.internalCallbackExecutor());
            invocation.setExecutor(userThreadPreferedExecutor);
            ListenableFuture rpcFuture = this.delegate.invoke(invocation);
            ListenableFuture rpcFuture = new UserThreadPreferedListenableFuture(userThreadPreferedExecutor, rpcFuture);
            return rpcFuture;
        } else if (InvokeMode.NEW_FUTURE == invokeType) {
            Executor futureListenerExecutor = FutureInvocationHelper.futureListenerExecutor;
            if (futureListenerExecutor == null) {
                futureListenerExecutor = this.threadPoolService.getExecutorManager().getDefaultExecutor();
            }

            UserThreadPreferedExecutor userThreadPreferedExecutor = new UserThreadPreferedExecutor((Executor)futureListenerExecutor);
            invocation.setExecutor(userThreadPreferedExecutor);
            ListenableFuture future = this.delegate.invoke(invocation);
            if (this.serviceMetadata.getConfigStyle() == EnumConfigStyle.HSF) {
                ListenableFuture