Future runImpl()

in lib/RetryableOperation.h [82:129]
46 lines of code
8 McCabe index (conditional complexity)

    Future<Result, T> runImpl(TimeDuration remainingTime) {
        std::weak_ptr<RetryableOperation<T>> weakSelf{this->shared_from_this()};
        func_().addListener([this, weakSelf, remainingTime](Result result, const T& value) {
            auto self = weakSelf.lock();
            if (!self) {
                return;
            }
            if (result == ResultOk) {
                promise_.setValue(value);
                return;
            }
            if (result != ResultRetryable) {
                promise_.setFailed(result);
                return;
            }
            if (remainingTime.total_milliseconds() <= 0) {
                promise_.setFailed(ResultTimeout);
                return;
            }

            auto delay = std::min(backoff_.next(), remainingTime);
            timer_->expires_from_now(delay);

            auto nextRemainingTime = remainingTime - delay;
            LOG_INFO("Reschedule " << name_ << " for " << delay.total_milliseconds()
                                   << " ms, remaining time: " << nextRemainingTime.total_milliseconds()
                                   << " ms");
            timer_->async_wait([this, weakSelf, nextRemainingTime](const boost::system::error_code& ec) {
                auto self = weakSelf.lock();
                if (!self) {
                    return;
                }
                if (ec) {
                    if (ec == boost::asio::error::operation_aborted) {
                        LOG_DEBUG("Timer for " << name_ << " is cancelled");
                        promise_.setFailed(ResultTimeout);
                    } else {
                        LOG_WARN("Timer for " << name_ << " failed: " << ec.message());
                    }
                } else {
                    LOG_DEBUG("Run operation " << name_ << ", remaining time: "
                                               << nextRemainingTime.total_milliseconds() << " ms");
                    runImpl(nextRemainingTime);
                }
            });
        });
        return promise_.getFuture();
    }