RawBinaryTranscoder problem

skaryshev · November 23, 2020, 11:19pm

DotNet SDK 3.0.7
I am trying some code samples right from SDK 3.0 documentation: Transcoders and Non-JSON Documents | Couchbase Docs and getting InvalidOperationException:The RawBinaryTranscoder can only decode byte arrays on ContentAs. What am I missing here?
My complete code:

static async Task Main(string args)
{
ICluster _cluster = await Cluster.ConnectAsync(“couchbase://192.168.0.6”, “test”, “test”);
var docId = “doc”;
var bytes = System.Text.Encoding.UTF8.GetBytes(“hello world”);
var bucket = await _cluster.BucketAsync(“TEST”);
var _collection = bucket.DefaultCollection();
await _collection.UpsertAsync(docId, bytes, options => options.Transcoder(new RawBinaryTranscoder()));
var result = await _collection.GetAsync(docId, options => options.Transcoder(new RawBinaryTranscoder()));
var returned = result.ContentAs<byte>();
string s = System.Text.Encoding.UTF8.GetString(returned);
Console.WriteLine(s);
}

btburnett3 · November 23, 2020, 11:58pm

Looking at the SDK code, it appears that for the RawBinaryTranscoder to work the data must also be flagged as binary on the server. You might try using the RawStringTranscoder, since you’re decoding the byte array to a string anyway.

github.com

couchbase/couchbase-net-client/blob/3.0.7/src/Couchbase/Core/IO/Transcoders/RawBinaryTranscoder.cs#L34


            {
                stream.Write(bytes, 0, bytes.Length);
                return;
            }

            throw new InvalidOperationException("The RawBinaryTranscoder can only encode byte arrays.");
        }

        public override T Decode<T>(ReadOnlyMemory<byte> buffer, Flags flags, OpCode opcode)
        {
            if (flags.DataFormat == DataFormat.Binary)
            {
                object value = DecodeBinary(buffer.Span);
                return (T) value;
            }

            throw new InvalidOperationException("The RawBinaryTranscoder can only decode byte arrays.");
        }
    }
}

skaryshev · November 24, 2020, 12:06am

Looks like the server knows the data is binary. Also I need it for binary data. The string here is coming from SDK doc sample.

btburnett3 · November 24, 2020, 12:30am

I believe that document is actually encoded as a Private data format (lower bits of flags = 1, not 3). However, regardless, it should work.

It appears that it’s a known bug which has been fixed for the next release: https://github.com/couchbase/couchbase-net-client/commit/0913ff1a4fb6d3202ee5408343e021373182a489#diff-5453e0f28a6f33806dd83565adf020c393637b16023e745c4cea3ec460f3d3b6

Until then, you might try the LegacyTranscoder. Looking at the logic I think it will work for you.

skaryshev · November 24, 2020, 12:34am

Off the topic but .RawStringTranscoder example from the same document. does not work either System.InvalidOperationException: 'The RawStringTranscoder can only decode strings.'https://docs.couchbase.com/dotnet-sdk/current/howtos/transcoders-nonjson.html#rawstringtranscoder

btburnett3 · November 24, 2020, 12:42am

@skaryshev

You’re right, it does have the same problem. It appears to have been fixed in the same change that fixed RawBinaryTranscoder.