std::tuple sample()

in rela/prioritized_replay.h [202:233]

• 27 lines of code
• 5 McCabe index (conditional complexity)

  std::tuple<DataType, torch::Tensor> sample(int batchsize, const std::string& device) {
    if (!sampledIds_.empty()) {
      std::cout << "Error: previous samples' priority has not been updated." << std::endl;
      assert(false);
    }

    DataType batch;
    torch::Tensor priority;
    if (prefetch_ == 0) {
      std::tie(batch, priority, sampledIds_) = sample_(batchsize, device);
      return std::make_tuple(batch, priority);
    }

    if (futures_.empty()) {
      std::tie(batch, priority, sampledIds_) = sample_(batchsize, device);
    } else {
      // assert(futures_.size() == 1);
      std::tie(batch, priority, sampledIds_) = futures_.front().get();
      futures_.pop();
    }

    while ((int)futures_.size() < prefetch_) {
      auto f = std::async(std::launch::async,
                          &PrioritizedReplay<DataType>::sample_,
                          this,
                          batchsize,
                          device);
      futures_.push(std::move(f));
    }

    return std::make_tuple(batch, priority);
  }