Function AwsWriteableStreamFactory

cpp/src/arrow/filesystem/s3fs.cc:1329–1331

By default, the AWS SDK reads object data into an auto-growing StringStream. To avoid copies, read directly into our preallocated buffer instead. See https://github.com/aws/aws-sdk-cpp/issues/64 for an alternative but functionally similar recipe.

// See https://github.com/aws/aws-sdk-cpp/issues/64 for an alternative but
// functionally similar recipe.
Aws::IOStreamFactory AwsWriteableStreamFactory(void* data, int64_t nbytes) {
  return [=]() { return Aws::New<StringViewStream>("", data, nbytes); };
}

Result<S3Model::GetObjectResult> GetObjectRange(Aws::S3::S3Client* client,
                                                const S3Path& path,