Appending bytes using Amazon S3 .Net SDK

Question

I have the following piece of code which works great for a simple file upload. But let's say I wanted to append to an existing file or simply upload random chunks of bytes, like the first and last 10 bytes? Is this even possible with the official SDK?

PutObjectRequest request = new PutObjectRequest();

FileStream fs = new FileStream(@"C:\myFolder\MyFile.bin", FileMode.Open);
request.WithInputStream(fs);
request.WithBucketName(bucketName);
request.WithKey(keyName);
client.PutObject(request);
fs.Close();

Answer 1

There is no way to append data to existing objects in S3. You have to overwrite the entire file.

Although, in saying that, it is possible to a degree with Amazon's large file support. With this uploads are broken into chunks and reassembled on S3. But you have to do it as part of a single transfer and its only for large files.

Answer 2

This previous answer appears to no longer be the case. You can currently manage an append like process by using an existing object as the initial part of a multi-part upload. Then delete the previous object when done transferring.

See:

http://docs.aws.amazon.com/AmazonS3/latest/dev/CopyingObjctsUsingLLNetMPUapi.html

http://docs.aws.amazon.com/AmazonS3/latest/API/mpUploadUploadPartCopy.html