@Advice.OnMethodExit(suppress = Throwable.class, onThrowable = Throwable.class)
public static void onExitFilterInvoke(@Advice.Argument(1) Invocation invocation,
                                      @Advice.Return Result result,
                                      @Nullable @Advice.Local("span") Span span,
                                      @Nullable @Advice.Thrown Throwable t,
                                      @Nullable @Advice.Local("transaction") Transaction transaction) {
    AbstractSpan<?> actualSpan = span != null ? span : transaction;
    if (actualSpan == null) {
        return;
    }
    actualSpan.captureException(t)
        .captureException(result.getException())
        .deactivate();
    if (!(RpcContext.getContext().getFuture() instanceof FutureAdapter)) {
        actualSpan.end();
    }
    // else: end when ResponseCallback is called (see AlibabaResponseCallbackInstrumentation)
}
 

private void asyncCallback(final Invoker<?> invoker, final Invocation invocation) {
//        从rpc上下文中取出异步执行结果的future
        Future<?> f = RpcContext.getContext().getFuture();
        if (f instanceof FutureAdapter) {
            ResponseFuture future = ((FutureAdapter<?>) f).getFuture();
            future.setCallback(new ResponseCallback() {
                @Override
                public void done(Object rpcResult) {
                    if (rpcResult == null) {
                        logger.error(new IllegalStateException("invalid result value : null, expected " + Result.class.getName()));
                        return;
                    }
                    ///must be rpcResult
                    if (!(rpcResult instanceof Result)) {
                        logger.error(new IllegalStateException("invalid result type :" + rpcResult.getClass() + ", expected " + Result.class.getName()));
                        return;
                    }
                    Result result = (Result) rpcResult;
                    if (result.hasException()) {
//                        触发异常回调=》
                        fireThrowCallback(invoker, invocation, result.getException());
                    } else {
//                        触发返回值回调=》
                        fireReturnCallback(invoker, invocation, result.getValue());
                    }
                }

                @Override
                public void caught(Throwable exception) {
//                    异常方法回调=》
                    fireThrowCallback(invoker, invocation, exception);
                }
            });
        }
    }
 

boolean ensureSpanFinishes(Future<Object> future, Invocation invocation, Invoker<?> invoker) {
    boolean deferFinish = false;
    if (future instanceof FutureAdapter) {
        deferFinish = true;
        ResponseFuture original = ((FutureAdapter<Object>) future).getFuture();
        ResponseFuture wrapped = new AsyncResponseFutureDelegate(invocation, invoker, original);
        // Ensures even if no callback added later, for example when a consumer, we finish the span
        wrapped.setCallback(null);
        RpcContext.getContext().setFuture(new FutureAdapter<>(wrapped));
    }
    return deferFinish;
}
 

private void asyncCallback(final Invoker<?> invoker, final Invocation invocation) {
    Future<?> f = RpcContext.getContext().getFuture();
    if (f instanceof FutureAdapter) {
        ResponseFuture future = ((FutureAdapter<?>)f).getFuture();
        future.setCallback(new ResponseCallback() {
            public void done(Object rpcResult) {
                if (rpcResult == null){
                    logger.error(new IllegalStateException("invalid result value : null, expected "+Result.class.getName()));
                    return;
                }
                ///must be rpcResult
                if (! (rpcResult instanceof Result)){
                    logger.error(new IllegalStateException("invalid result type :" + rpcResult.getClass() + ", expected "+Result.class.getName()));
                    return;
                }
                Result result = (Result) rpcResult;
                if (result.hasException()) {
                    fireThrowCallback(invoker, invocation, result.getException());
                } else {
                    fireReturnCallback(invoker, invocation, result.getValue());
                }
            }
            public void caught(Throwable exception) {
                fireThrowCallback(invoker, invocation, exception);
            }
        });
    }
}
 

private void asyncCallback(final Invoker<?> invoker, final Invocation invocation) {
    Future<?> f = RpcContext.getContext().getFuture();
    if (f instanceof FutureAdapter) {
        ResponseFuture future = ((FutureAdapter<?>)f).getFuture();
        future.setCallback(new ResponseCallback() {
            public void done(Object rpcResult) {
                if (rpcResult == null){
                    logger.error(new IllegalStateException("invalid result value : null, expected "+Result.class.getName()));
                    return;
                }
                ///must be rpcResult
                if (! (rpcResult instanceof Result)){
                    logger.error(new IllegalStateException("invalid result type :" + rpcResult.getClass() + ", expected "+Result.class.getName()));
                    return;
                }
                Result result = (Result) rpcResult;
                if (result.hasException()) {
                    fireThrowCallback(invoker, invocation, result.getException());
                } else {
                    fireReturnCallback(invoker, invocation, result.getValue());
                }
            }
            public void caught(Throwable exception) {
                fireThrowCallback(invoker, invocation, exception);
            }
        });
    }
}
 

private void asyncCallback(final Invoker<?> invoker, final Invocation invocation) {
    Future<?> f = RpcContext.getContext().getFuture();
    if (f instanceof FutureAdapter) {
        ResponseFuture future = ((FutureAdapter<?>)f).getFuture();
        future.setCallback(new ResponseCallback() {
            public void done(Object rpcResult) {
                if (rpcResult == null){
                    logger.error(new IllegalStateException("invalid result value : null, expected "+Result.class.getName()));
                    return;
                }
                ///must be rpcResult
                if (! (rpcResult instanceof Result)){
                    logger.error(new IllegalStateException("invalid result type :" + rpcResult.getClass() + ", expected "+Result.class.getName()));
                    return;
                }
                Result result = (Result) rpcResult;
                if (result.hasException()) {
                    fireThrowCallback(invoker, invocation, result.getException());
                } else {
                    fireReturnCallback(invoker, invocation, result.getValue());
                }
            }
            public void caught(Throwable exception) {
                fireThrowCallback(invoker, invocation, exception);
            }
        });
    }
}
 

private void asyncCallback(final Invoker<?> invoker, final Invocation invocation) {
    Future<?> f = RpcContext.getContext().getFuture();
    if (f instanceof FutureAdapter) {
        ResponseFuture future = ((FutureAdapter<?>)f).getFuture();
        future.setCallback(new ResponseCallback() {
            public void done(Object rpcResult) {
                if (rpcResult == null){
                    logger.error(new IllegalStateException("invalid result value : null, expected "+Result.class.getName()));
                    return;
                }
                ///must be rpcResult
                if (! (rpcResult instanceof Result)){
                    logger.error(new IllegalStateException("invalid result type :" + rpcResult.getClass() + ", expected "+Result.class.getName()));
                    return;
                }
                Result result = (Result) rpcResult;
                if (result.hasException()) {
                    fireThrowCallback(invoker, invocation, result.getException());
                } else {
                    fireReturnCallback(invoker, invocation, result.getValue());
                }
            }
            public void caught(Throwable exception) {
                fireThrowCallback(invoker, invocation, exception);
            }
        });
    }
}
 

private void asyncCallback(final Invoker<?> invoker, final Invocation invocation) {
    Future<?> f = RpcContext.getContext().getFuture();
    if (f instanceof FutureAdapter) {
        ResponseFuture future = ((FutureAdapter<?>)f).getFuture();
        future.setCallback(new ResponseCallback() {
            public void done(Object rpcResult) {
                if (rpcResult == null){
                    logger.error(new IllegalStateException("invalid result value : null, expected "+Result.class.getName()));
                    return;
                }
                ///must be rpcResult
                if (! (rpcResult instanceof Result)){
                    logger.error(new IllegalStateException("invalid result type :" + rpcResult.getClass() + ", expected "+Result.class.getName()));
                    return;
                }
                Result result = (Result) rpcResult;
                if (result.hasException()) {
                    fireThrowCallback(invoker, invocation, result.getException());
                } else {
                    fireReturnCallback(invoker, invocation, result.getValue());
                }
            }
            public void caught(Throwable exception) {
                fireThrowCallback(invoker, invocation, exception);
            }
        });
    }
}
 

@Advice.OnMethodEnter(suppress = Throwable.class)
private static void onEnter(@Advice.Argument(0) Future<?> future) {
    if (future instanceof FutureAdapter) {
        ElasticApmAgent.ensureInstrumented(((FutureAdapter<?>) future).getFuture().getClass(), RESPONSE_FUTURE_INSTRUMENTATION);
    }
}
 

/**
 * rpc client handler
 * @param rpcContext
 * @param invoker
 * @param invocation
 * @return
 */
private Result doClientFilter(RpcContext rpcContext, Invoker<?> invoker, Invocation invocation) {
    // to build tracer instance
    if (dubboConsumerSofaTracer == null) {
        this.dubboConsumerSofaTracer = DubboConsumerSofaTracer
            .getDubboConsumerSofaTracerSingleton();
    }
    // get methodName
    String methodName = rpcContext.getMethodName();
    // get service interface
    String service = invoker.getInterface().getSimpleName();
    // build a dubbo rpc span
    SofaTracerSpan sofaTracerSpan = dubboConsumerSofaTracer.clientSend(service + "#"
                                                                       + methodName);
    // set tags to span
    appendRpcClientSpanTags(invoker, sofaTracerSpan);
    // do serialized and then transparent transmission to the rpc server
    String serializedSpanContext = sofaTracerSpan.getSofaTracerSpanContext()
        .serializeSpanContext();
    //put into attachments
    invocation.getAttachments().put(CommonSpanTags.RPC_TRACE_NAME, serializedSpanContext);

    boolean isOneWay = false, deferFinish = false;

    // check invoke type
    boolean isAsync = RpcUtils.isAsync(invoker.getUrl(), invocation);

    // set invoke type tag
    if (isAsync) {
        sofaTracerSpan.setTag(CommonSpanTags.INVOKE_TYPE, "future");
    } else {
        isOneWay = RpcUtils.isOneway(invoker.getUrl(), invocation);
        if (isOneWay) {
            sofaTracerSpan.setTag(CommonSpanTags.INVOKE_TYPE, "oneway");
        } else {
            sofaTracerSpan.setTag(CommonSpanTags.INVOKE_TYPE, "sync");
        }
    }

    Result result;
    Throwable exception = null;
    String resultCode = SofaTracerConstant.RESULT_CODE_SUCCESS;
    try {
        // do invoke
        result = invoker.invoke(invocation);
        if (result.hasException()) {
            exception = result.getException();
        }
        // the case on async client invocation
        Future<Object> future = rpcContext.getFuture();
        if (future instanceof FutureAdapter) {
            deferFinish = ensureSpanFinishes(future, invocation, invoker);
        }
        return result;
    } catch (RpcException e) {
        exception = e;
        throw e;
    } catch (Throwable t) {
        exception = t;
        throw new RpcException(t);
    } finally {
        if (exception != null) {
            // finish span on exception, delay to clear tl in handleError
            handleError(exception, null);
        } else {
            // sync invoke
            if (isOneWay || !deferFinish) {
                dubboConsumerSofaTracer.clientReceive(resultCode);
            } else {
                // to clean SofaTraceContext
                SofaTraceContext sofaTraceContext = SofaTraceContextHolder
                    .getSofaTraceContext();
                SofaTracerSpan clientSpan = sofaTraceContext.pop();
                if (clientSpan != null) {
                    // Record client send event
                    sofaTracerSpan.log(LogData.CLIENT_SEND_EVENT_VALUE);
                }
                // cache the current span
                TracerSpanMap.put(getTracerSpanMapKey(invoker), sofaTracerSpan);
                if (clientSpan != null && clientSpan.getParentSofaTracerSpan() != null) {
                    //restore parent
                    sofaTraceContext.push(clientSpan.getParentSofaTracerSpan());
                }
            }
        }
    }
}
 

@Override
public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    if(!RpcTraceContext.getTraceConfig().isEnabled()){
        return invoker.invoke(invocation);
    }

    ZipkinCollectorConfigurationFactory zipkinCollectorConfigurationFactory=
            SpringContextUtils.getApplicationContext().getBean(ZipkinCollectorConfigurationFactory.class);
    Tracer tracer= zipkinCollectorConfigurationFactory.getTracing().tracer();

    if(null==RpcTraceContext.getTraceId()){
        RpcTraceContext.start();
        RpcTraceContext.setTraceId(IdUtils.get());
        RpcTraceContext.setParentId(null);
        RpcTraceContext.setSpanId(IdUtils.get());
    }
    else {
        RpcTraceContext.setParentId(RpcTraceContext.getSpanId());
        RpcTraceContext.setSpanId(IdUtils.get());
    }
    TraceContext traceContext= TraceContext.newBuilder()
            .traceId(RpcTraceContext.getTraceId())
            .parentId(RpcTraceContext.getParentId())
            .spanId(RpcTraceContext.getSpanId())
            .sampled(true)
            .build();

    Span span=tracer.toSpan(traceContext).start();

    invocation.getAttachments().put(RpcTraceContext.TRACE_ID_KEY, String.valueOf(span.context().traceId()));
    invocation.getAttachments().put(RpcTraceContext.SPAN_ID_KEY, String.valueOf(span.context().spanId()));
    logger.info("consumer:traceId={},parentId={},spanId={}",
            span.context().traceId(),
            span.context().parentId(),
            span.context().spanId());

    RpcContext rpcContext = RpcContext.getContext();
    boolean isAsync=false;
    Future<Object> future = rpcContext.getFuture();
    if (future instanceof FutureAdapter) {
        isAsync = true;
        ((FutureAdapter) future).getFuture().setCallback(new AsyncSpanCallback(span));
    }

    Result result = null;
    boolean isOneway = RpcUtils.isOneway(invoker.getUrl(), invocation);
    try {
        result = invoker.invoke(invocation);
    }
    finally {
        if(isOneway) {
            span.flush();
        }
        else if(!isAsync) {
            span.finish();
        }
    }

    return result;
}