Class AsyncProgressQueueWorker

nan.h:2310–2379

abstract */

template<class T>
/* abstract */
class AsyncProgressQueueWorker : public AsyncBareProgressQueueWorker<T> {
 public:
  explicit AsyncProgressQueueWorker(
      Callback *callback_,
      const char* resource_name = "nan:AsyncProgressQueueWorker")
      : AsyncBareProgressQueueWorker<T>(callback_) {
    uv_mutex_init(&async_lock);
  }

  virtual ~AsyncProgressQueueWorker() {
    uv_mutex_lock(&async_lock);

    while (!asyncdata_.empty()) {
      std::pair<T*, size_t> &datapair = asyncdata_.front();
      T *data = datapair.first;

      asyncdata_.pop();

      delete[] data;
    }

    uv_mutex_unlock(&async_lock);
    uv_mutex_destroy(&async_lock);
  }

  void WorkComplete() {
    WorkProgress();
    AsyncWorker::WorkComplete();
  }

  void WorkProgress() {
    uv_mutex_lock(&async_lock);

    while (!asyncdata_.empty()) {
      std::pair<T*, size_t> &datapair = asyncdata_.front();

      T *data = datapair.first;
      size_t size = datapair.second;

      asyncdata_.pop();
      uv_mutex_unlock(&async_lock);

      // Don't send progress events after we've already completed.
      if (this->callback) {
          this->HandleProgressCallback(data, size);
      }

      delete[] data;

      uv_mutex_lock(&async_lock);
    }

    uv_mutex_unlock(&async_lock);
  }

 private:
  void SendProgress_(const T *data, size_t count) {
    T *new_data = new T[count];