Method Lookup

cpp/src/arrow/filesystem/s3fs.cc:1033–1048

class EndpointProviderCache {
 public:
  std::shared_ptr<Aws::S3::S3EndpointProviderBase> Lookup(
      const Aws::S3::S3ClientConfiguration& config) {
    auto key = EndpointConfigKey(config);
    CacheValue* value;
    {
      std::unique_lock lock(mutex_);
      value = &cache_[std::move(key)];
    }
    std::call_once(value->once, [&]() {
      auto endpoint_provider = std::make_shared<Aws::S3::S3EndpointProvider>();
      endpoint_provider->InitBuiltInParameters(config);
      value->endpoint_provider =
          std::make_shared<InitOnceEndpointProvider>(std::move(endpoint_provider));
    });
    return value->endpoint_provider;
  }

  void Reset() {
    std::unique_lock lock(mutex_);