NodeJS Addon从NAN AsyncWorker :: Execute内部调用Javascript回调

Question

我想从异步插件函数中调用nodejs回调.我已经看到了同步示例(这里),我正在使用一个很棒的异步示例(这里)作为起始基础.

但是,当我尝试执行给c ++ AsyncWorker子类的回调时,我收到了Segmentation错误.

这是我的代码:

#include <nan.h>
#include <functional>
#include <iostream>
#include <exception>
using namespace Nan;
using namespace v8;
using namespace std;

class ScriptWorker : public AsyncWorker {
  public:
    ScriptWorker(Callback *callback, const std::map<std::string, Callback*>)
    : AsyncWorker(callback), script(script), cbs(cbs) {}

    ~ScriptWorker() {}

    void Execute () {

      // ------------------------
      // Segmentation fault after
      // ------------------------

      Local<Value> argv[] = {
        New<v8::Number>(id)
      };

      // -------------------------
      // Segmentation fault before
      // -------------------------

      cbs["getUser"]->Call(1, argv);
    }

  private:
    std::string script;
    std::map<std::string, Callback*> cbs;
};

NAN_METHOD(Method) {
  Local<Object> array = info[0]->ToObject();
  Callback *callback = new Callback(info[1].As<Function>());

  // Build up callbacks passed in from javascript.
  // Will be a dynamic loop, but for now, hard code the one getUser example.
  std::map<std::string, Callback*> cbs;
  cbs.insert(std::pair<std::string, Callback*>("getUser",
    new Callback(
      array->Get(
        v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), "getUser")
      ).As<Function>()
    )
  ));
  AsyncQueueWorker(new ScriptWorker(callback, cbs));
}

NAN_MODULE_INIT(Init) {
  Nan::Set(target, Nan::New<String>("hello").ToLocalChecked(), Nan::GetFunction(Nan::New<FunctionTemplate>(Method)).ToLocalChecked());
}

NODE_MODULE(hello, Init)

我的问题:

1. 我不应该使用Nan的AsyncWorker而是自己滚动吗？
2. 如何设置执行函数以调用Javascript？

Answer 1

编辑:

看到这个回购:

https://github.com/xavero/node_addon_sample

它有一个关于如何使用回调函数和从C land发出事件的示例.

您不应该在ScriptWorker的Execute方法中调用v8/Nan函数,否则会出现段错误.覆盖HandleOKCallback函数以使用javascript回调.

要从javascript中调用,请在c ++插件中调用:

NAN_MODULE_INIT(Init) {
  Nan::Set(target, Nan::New("myJsFunctionName").ToLocalChecked(),
    Nan::GetFunction(Nan::New<FunctionTemplate>(Method)).ToLocalChecked());
}

NODE_MODULE(anyNameHere, Init)

并在您的JavaScript中:

// run "npm install bindings --save" in console first
var addon = require('bindings')('NativeExtension');

addon.myJsFunctionName({ foo: "bar"}, (arg1,arg2) => console.log(`${arg1} - ${arg2}`))