Per call storage in .asmx web service.

Question

User-313978683 posted

We have an existing .asmx web service that is using a static collection to store errors encountered during form processing.  Unfortunately, as you might have already guessed, this is not thread safe.  Consequently we are looking for a thread safe way to do this.  I would prefer to avoid passing an error object back and forth with every call.  I have currently re-written it to use the HttpContext.Current.Items collection (Asp.Net Compatibility is enabled), but was wondering if anyone could think of a better way to implement this?  Is there some kind of session-state like storage available in a .asmx web service that I am not aware of?

Thanks in advance!

-Nathan

Answer 1

User-313978683 posted

This is the current implementation for the fix.  Is there a better way I could have done this?

public class ContextErrorCollection
{
    public static void AddToErrorCollection(string error)
    {
        var nsec = ErrorCollection;
        nsec.Add(error);
        ErrorCollection = nsec;
    }

    public static List<string> ErrorCollection
    {
        get
        {
            var nsec = HttpContext.Current.Items["ErrorCollection"] as NonStaticErrorCollection ?? new NonStaticErrorCollection();
            return nsec.ItemList;
        }

        set
        {
            var nsec = new NonStaticErrorCollection();
            foreach (string error in value)
            {
                nsec.ItemList.Add(error);
            }
            HttpContext.Current.Items["ErrorCollection"] = nsec;
        }

    }
}

public class NonStaticErrorCollection
{
    public string[] list()
    {
        return m_sList.ToArray();
    }

    public List<string> ItemList
    {
        get
        {
            if (m_sList == null) return new List<string>();

            return m_sList;
        }
    }

    private readonly List<string> m_sList = new List<string>();
}

//Calling Code
ContextErrorCollection.AddToErrorCollection(string.Format("Adding error number {0} to list...", i));