Question

I’m left with an old code that uses remoting. I need to upgrade this code to WCF.

Quite frankly, I’m stuck on how to redesign the interface that client & server use for communication. It looks like this:

public interface IDDCEngine
    {
        ReadDiagnosticEntirePointValuesResponse ReadDiagnosticEntirePointValues(string host);
        GetEntirePointListResponse GetEntirePointList(string host);

        SetSerialPortListResponse SetSerialPointList(string host, SetSerialPortList serialPortList);
        SetNationalListResponse SetNationalList(string host, SetNationalList nationalList, int count);
        SetModbusListResponse SetModbusList(string host, SetModbusList modbusList, int count);

        SetIOPointListResponse SetIOPointList(string host, SetIOPoint pointList, int count);
        GetIOPointResponse GetIOPointList(string host);
        SetLogicListResponse SetLogicList(string host, SetLogicList logicList, int count);
        GetDDCVersionResponse GetDDCVersion(string host);
        GetDDCUptimeResponse GetDDCUptime(string host);
        GetDDCCPUMemoryStatusResponse GetDDCCPUMemoryStatus(string host, int count);
        ...about 20 more interfaces
    }

And the classes for request/response:

[Serializable]
    public class SetIOPoint
    {
        public string[] pointidentifier;
        public string[] pointname;
        public string[] pointaddress;
        public string[] pointtype;
        public string[] devicetype;
        public string[] description;
        public string[] backup;
        public string[] relinquishdefault;
        public string[] unit;
        public string[] minpresvalue;
        public string[] maxpresvalue;
        public string[] correctvalue;
        public string[] covenable;
        public string[] covincrement;
        public string[] covtarget;
        public string[] covlifetime;
        public string[] historyenable;
        public string[] historyincrement;
        public string[] alarmenable;
        public string[] highlimit;
        public string[] lowlimit;
        public string[] polarity;
        public string[] inactivetext;
        public string[] activetext;
        public string[] feedbackenable;
        public string[] feedbacktime;
        public string[] numofstates;
        public string[] statetext;
    }

    [Serializable]
    public class GetIOPointResponse
    {
        public string[] pointidentifier;
        public string[] pointname;
        public string[] pointaddress;
        public string[] pointtype;
        public string[] devicetype;
        public string[] description;
        public string[] backup;
        public string[] relinquishdefault;
        public string[] unit;
        public string[] minpresvalue;
        public string[] maxpresvalue;
        public string[] correctvalue;
        public string[] covenable;
        public string[] covincrement;
        public string[] covtarget;
        public string[] covlifetime;
        public string[] historyenable;
        public string[] historyincrement;
        public string[] alarmenable;
        public string[] highlimit;
        public string[] lowlimit;
        public string[] polarity;
        public string[] inactivetext;
        public string[] activetext;
        public string[] feedbackenable;
        public string[] feedbacktime;
        public string[] numofstates;
        public string[] statetext;
    }

    [Serializable]
public class RequestDDCRebootResponse
{
    public string result;
}

[Serializable]
public class GetDDCCurrenttimeResponse
{
    public string result;
}

[Serializable]
public class StartDDCBackupResponse
{
    public string result;
}

[Serializable]
public class EndDDCBackupResponse
{
    public string result;
}

[Serializable]
public class StartDDCRestoreResponse
{
    public string result;
}

[Serializable]
public class EndDDCRestoreResponse
{
    public string result;
}
...List goes ON

Pretty badly written interfaces and datastructure. I’d like to rewrite the interfaces and the datastructure so that I don’t have to define millions of operationcontracts.

Are there any good recommendations on strategies of solid interface and datastructure design for WCF?

Answer 1

Take a look at this article:

Writing Highly Maintainable WCF Services

This article talks writing a WCF service as realy thin layer on top of an SOLIDly designed architectural pattern based on commands and queries. When using this command/query style of programming, the WCF service can be defined as a really tiny piece of infrastructure code that won’t have to be changed, even when new operations are added.