Question

I’m trying to fix a bug where the following code results in a 0 byte file on S3, and no error message.

This code feeds in a Stream (from the poorly-named FileUpload4) which contains an image and the desired image path (from a database wrapper object) to Amazon’s S3, but the file itself is never uploaded.

CloudUtils.UploadAssetToCloud(FileUpload4.FileContent, ((ImageContent)auxSRC.Content).PhysicalLocationUrl);
ContentWrapper.SaveOrUpdateAuxiliarySalesRoleContent(auxSRC);

The second line simply saves the database object which stores information about the (supposedly) uploaded picture. This save is going through, demonstrating that the above line runs without error.

The first line above calls in to this method, after retrieving an appropriate bucketname:

public static bool UploadAssetToCloud(Stream asset, string path, string bucketName, AssetSecurity security = AssetSecurity.PublicRead)
{
    TransferUtility txferUtil;
    S3CannedACL ACL = GetS3ACL(security);

    using (txferUtil = new Amazon.S3.Transfer.TransferUtility(AWSKEY, AWSSECRETKEY))
    {
        TransferUtilityUploadRequest request = new TransferUtilityUploadRequest()
            .WithBucketName(bucketName)
            .WithTimeout(TWO_MINUTES)
            .WithCannedACL(ACL)
            .WithKey(path);
        request.InputStream = asset;
        txferUtil.Upload(request);
    }

    return true;
}

I have made sure that the stream is a good stream – I can save it anywhere else I have permissions for, the bucket exists and the path is fine (the file is created at the destination on S3, it just doesn’t get populated with the content of the stream). I’m close to my wits end, here – what am I missing?

EDIT: One of my coworkers pointed out that it would be better to the FileUpload’s PostedFile property. I’m now pulling the stream off of that, instead. It still isn’t working.

Answer 1

Is the stream positioned correctly? Check asset.Position to make sure the position is set to the beginning of the stream.

asset.Seek(0, SeekOrigin.Begin);

Edit

OK, more guesses (I’m down to guesses, though):
(all of this is assuming that you can still read from your incoming stream just fine “by hand”)

1. Just for testing, try one of the simpler Upload methods on the TransferUtility — maybe one that just takes a file path string. If that works, then maybe there are additional properties to set on the UploadRequest object.

2. If you hook the UploadProgressEvent on the UploadRequest object, do you get any additional clues to what’s going wrong?

3. I noticed that the UploadRequest’s api includes both an InputStream property, and a WithInputStream fluent API. Maybe there’s a bug with setting InputStream? Maybe try using the .WithInputStream API instead