Method getFuture

bolt/common/caching/AsyncDataCache.h:296–301

Returns a future that will be realized when a caller can retry getting 'this'. Must be called inside the mutex of 'shard_'.

  // Returns a future that will be realized when a caller can retry getting
  // 'this'. Must be called inside the mutex of 'shard_'.
  folly::SemiFuture<bool> getFuture() {
    if (promise_ == nullptr) {
      promise_ = std::make_unique<folly::SharedPromise<bool>>();
    }
    return promise_->getSemiFuture();
  }

  // Holds an owning reference to the file number.
  FileCacheKey key_;