Download large files in ASP.NET

[cvetomir-todorov]

I am simply referencing the incorrectly closed issue #225 about the same problem which is especially valid in ASP.NET and, consequently, for a big part, if not majority, of .NET applications.

Giving access to the underlying Stream for the file object stored in MinIO only via a callback is not idiomatic .NET code. It is weird and unusable in the use case where an ASP.NET controller needs to return the large file via return File(stream, mimeType);

[HttpGet]
public async Task<IActionResult> DownloadFile(
    [FromQuery] string bucketName,
    [FromQuery] string objectName)
{
    GetObjectArgs getObjectArgs = new GetObjectArgs()
        .WithBucket(bucketName)
        .WithObject(objectName)
        .WithCallbackStream(async (stream, ct) =>
        {
            // copying the stream to Response.Body results into
            // the entire file being loaded in the memory of the server
        });
    ObjectStat objectStat = await minio.GetObjectAsync(getObjectArgs);
    
    return File(whatStream???, objectStat.ContentType);
}

What is needed here is the actual Stream instance, so that it can be passed to the File method.

[martijn00]

Isn't it an idea to implement https://github.com/microsoft/Microsoft.IO.RecyclableMemoryStream and instead of a callback return that?