Question

I have turned on the versioning option for my bucket. I have also uploaded a file twice to a folder in my bucket with the same name, creating two revisions of the file.

e.g. mybucket/myfile.jpg (revision 1 and revision 2 (current))

I am trying to use the AmazonS3 .NET tools to get a list of the versions for a single file as mentioned above. As I want the functionality for a user to be able to download a previous version of the uploaded file.

Here is a method that I have created, I am able to get a list of all the files in my bucket/folder. But not a specific file in the bucket/folder (I call it a folder, but is is a key / object in itself).

public String AmazonS3GetObjectVersions(Guid DocumentId)
{
    AmazonS3 s3Client = AmazonS3ClientConnection();

    GetObjectMetadataRequest ORequest = new GetObjectMetadataRequest();
    ORequest.BucketName = DocumentStorageFolder(DocumentId); // e.g. mybucket
    ORequest.Key = DocumentStorageReference(DocumentId); // e.g. myfolder/myfile.jpg

    GetObjectMetadataResponse OResponse = s3Client.GetObjectMetadata(ORequest);

    S3ObjectVersion version = new S3ObjectVersion();
    version.BucketName = DocumentStorageFolder(DocumentId);
    version.Key = DocumentStorageReference(DocumentId);
    version.IsDeleteMarker = false;

    ListVersionsRequest Request = new ListVersionsRequest();
    Request.BucketName = DocumentStorageFolder(DocumentId);

    String tmp = DocumentStorageReference(DocumentId);

    string[] tmparr = tmp.Split('/');

    Request.KeyMarker = tmparr[0];
    //Request.Delimiter = "/";
    //Request.MaxKeys = int.Parse(appConfig["MAX_VERSIONS"]);

    ListVersionsResponse Response = s3Client.ListVersions(Request);

   //Response.NextKeyMarker = tmparr[1];

   Response.KeyMarker = tmparr[1];

   List<S3ObjectVersion> Versions = new List<S3ObjectVersion>();

   Versions = Response.Versions;

   return Versions.ToString();
}

I have tried a few of the available classes, however I am unable to get the version history for a single file. (Probably missing something small)

Answer 1

As you mentioned, you are missing a small thing. Use prefix of the ListVersionsRequest

E.g.

ListVersionsRequest Request = new ListVersionsRequest();
Request.BucketName = DocumentStorageFolder(DocumentId);
Request.Prefix = KeyName

Kamal