/src/NUnit/core/Builders/ProviderCache.cs

// ****************************************************************

// Copyright 2008, Charlie Poole

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org.

// ****************************************************************



using System;

using System.Collections;

using System.Text;



namespace NUnit.Core.Builders

{

    class ProviderCache

    {

        private static IDictionary instances = new Hashtable();



        public static object GetInstanceOf(Type providerType)

        {

            CacheEntry entry = new CacheEntry(providerType);



            object instance = instances[entry];

            return instance == null

                ? instances[entry] = Reflect.Construct(providerType)

                : instance;

        }



        public static void Clear()

        {

            foreach (object key in instances.Keys)

            {

                IDisposable provider = instances[key] as IDisposable;

                if (provider != null)

                    provider.Dispose();

            }



            instances.Clear();

        }



        class CacheEntry

        {

            private Type providerType;



            public CacheEntry(Type providerType)

            {

                this.providerType = providerType;

            }



            public override bool Equals(object obj)

            {

                CacheEntry other = obj as CacheEntry;

                if (other == null) return false;



                return this.providerType == other.providerType;

            }



            public override int GetHashCode()

            {

                return providerType.GetHashCode();

            }

        }

    }

}