Does Streaming a WCF Soap Help the Client Send Using Less Memory?

Friday, October 22, 2010 by Nate Bross

Someone asked on Stack Overflow:

I have a windows mobile application that sends data via WCF to a server.

The data it sends sometimes exceeds the limit on the windows mobile device. I am wondering if streaming would help not need to hold all the data I must send in memory at once.

Here is a simple example:

[DataContract]
public class MainContract
{
    [DataMember]
    public Guid  ID { get; set; }

    [DataMember]
    public List<SubContract> SubContract { get; set; }
}

[DataContract]
public class SubContract
{
    [DataMember]
    public Guid ID { get; set; }

    [DataMember]
    public string ImageCaption { get; set; }

    [DataMember]
    public Byte[] ImageAsBytes { get; set; }
}

Say I have only 1 MainContract object. But it has a lot of SubContract objects in it. (My real scenario is more compelex).

Holding all of MainContract in memory is too much for the client side to do.

Will streaming allow me to send send the data over the wire in pieces? Or do I still have to buffer it all on the client side and the streaming just helps with the receiving of large data?

I posted the following answer, which was chosen as the accepted answer and received 1 upvote:

As far as I know, if your method accepts a MainContract you will need to have that completely in memory on the client side in order to stream the serialized result to the WCF host.

If loading up a full MainContract will take too much memory on the client side, I would adjust the service to allow for something like this:

public Guid CreateMainContract(MainContract obj); // return unique id
public Guid CreateSubContract(Guid mainContractToAddTo, SubContract obj);

and then modify the calling code to pseduo-stream the data to the WCF host, by means of calling the above operations in a loop. (Obviously, you’ll need to change it up for update/delete situations, etc).

Originally posted on Stack Overflow — 1 upvotes (accepted answer). Licensed under CC BY-SA.