DataServiceFactory.cs :  » Bloggers » dasBlog » newtelligence » DasBlog » Runtime » C# / CSharp Open Source

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;

namespace newtelligence.DasBlog.Runtime{
    public static class DataServiceFactory<T>
    {
        static readonly object servicesLock = new object();

        static readonly IDictionary<string, T> services = new Dictionary<string, T>(StringComparer.OrdinalIgnoreCase);

        public static T GetService(string location, Type defaultType)
        {
            return GetService(location, defaultType, null);
        }

        public static T GetService(string location, Type defaultType, params object[] optArgs)
        {
            if (string.IsNullOrEmpty(location)) { throw new ArgumentNullException("location"); }

            T service;

            // try to get the service
            if (!services.TryGetValue(location, out service))
            {
                // setup the arguments for the dynamic constructor
                // invocation.
                object[] args;

                if (optArgs == null || optArgs.Length == 0)
                {
                    args = new object[] { location };
                }
                else
                {
                    args = new object[optArgs.Length + 1];
                    args[0] = location;
                    Array.Copy(optArgs, 0, args, 1, optArgs.Length);
                }

                // find the type to init
                var type = StorageConfigManager.GetServiceType(typeof(T)) ?? defaultType;

                lock (servicesLock)
                {
                    // did someone beat us?
                    if (!services.TryGetValue(location, out service))
                    {
                        // Create new
                        service = (T)Activator.CreateInstance(type, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.CreateInstance | BindingFlags.Instance, null, args, null);
                        services.Add(location, service);
                    }
                }
            }
            return service;
        }
    }
}