12 files changed, 509 insertions, 46 deletions

diff --git a/OpenSim/Framework/Communications/Cache/AssetCache.cs b/OpenSim/Framework/Communications/Cache/AssetCache.cs
index 1c8f9d6..76c6045 100644
--- a/OpenSim/Framework/Communications/Cache/AssetCache.cs
+++ b/OpenSim/Framework/Communications/Cache/AssetCache.cs
@@ -48,8 +48,67 @@ namespace OpenSim.Framework.Communications.Cache
     /// sends packetised data directly back to the client.  The only point where they meet is AssetReceived() and
     /// AssetNotFound(), which means they do share the same asset and texture caches.I agr
 
-    public class AssetCache : IAssetCache, IAssetReceiver
+    public class AssetCache : IAssetCache
     {
+
+        #region IPlugin
+
+        /// <summary>
+        /// The methods and properties in this section are needed to
+        /// support the IPlugin interface. They cann all be overridden
+        /// as needed by a derived class.
+        /// </summary>
+
+        public virtual string Name
+        {
+            get { return "OpenSim.Framework.Communications.Cache.AssetCache"; }
+        }
+
+        public virtual string Version
+        {
+            get { return "1.0"; }
+        }
+
+        public virtual void Initialise()
+        {
+            m_log.Debug("[ASSET CACHE]: Asset cache null initialisation");
+        }
+
+        public virtual void Initialise(IAssetServer assetServer)
+        {
+            m_log.Debug("[ASSET CACHE]: Asset cache server-specified initialisation");
+            m_log.InfoFormat("[ASSET CACHE]: Asset cache initialisation [{0}/{1}]", Name, Version);
+
+            Initialize();
+
+            m_assetServer = assetServer;
+            m_assetServer.SetReceiver(this);
+
+            Thread assetCacheThread = new Thread(RunAssetManager);
+            assetCacheThread.Name = "AssetCacheThread";
+            assetCacheThread.IsBackground = true;
+            assetCacheThread.Start();
+            ThreadTracker.Add(assetCacheThread);
+
+        }
+
+        public virtual void Initialise(ConfigSettings settings, IAssetServer assetServer)
+        {
+            m_log.Debug("[ASSET CACHE]: Asset cache configured initialisation");
+            Initialise(assetServer);
+        }
+
+        public AssetCache()
+        {
+            m_log.Debug("[ASSET CACHE]: Asset cache (plugin constructor)");
+        }
+
+        public void Dispose()
+        {
+        }
+
+        #endregion
+
         protected ICache m_memcache = new SimpleMemoryCache();
 
         private static readonly ILog m_log
@@ -83,7 +142,7 @@ namespace OpenSim.Framework.Communications.Cache
         /// <summary>
         /// The 'server' from which assets can be requested and to which assets are persisted.
         /// </summary>
-        private readonly IAssetServer m_assetServer;
+        private IAssetServer m_assetServer;
 
         public IAssetServer AssetServer
         {
@@ -132,17 +191,8 @@ namespace OpenSim.Framework.Communications.Cache
         /// <param name="assetServer"></param>
         public AssetCache(IAssetServer assetServer)
         {
-            m_log.Info("[ASSET CACHE]: Creating Asset cache");
-            Initialize();
-
-            m_assetServer = assetServer;
-            m_assetServer.SetReceiver(this);
-
-            Thread assetCacheThread = new Thread(RunAssetManager);
-            assetCacheThread.Name = "AssetCacheThread";
-            assetCacheThread.IsBackground = true;
-            assetCacheThread.Start();
-            ThreadTracker.Add(assetCacheThread);
+            m_log.Info("[ASSET CACHE]: Asset cache direct constructor");
+            Initialise(assetServer);
         }
 
         /// <summary>
@@ -342,7 +392,7 @@ namespace OpenSim.Framework.Communications.Cache
         }
 
         // See IAssetReceiver
-        public void AssetReceived(AssetBase asset, bool IsTexture)
+        public virtual void AssetReceived(AssetBase asset, bool IsTexture)
         {
 
             AssetInfo assetInf = new AssetInfo(asset);
@@ -393,7 +443,7 @@ namespace OpenSim.Framework.Communications.Cache
         }
 
         // See IAssetReceiver
-        public void AssetNotFound(UUID assetID, bool IsTexture)
+        public virtual void AssetNotFound(UUID assetID, bool IsTexture)
         {
 //            m_log.WarnFormat("[ASSET CACHE]: AssetNotFound for {0}", assetID);
 
diff --git a/OpenSim/Framework/Communications/Cache/AssetServerBase.cs b/OpenSim/Framework/Communications/Cache/AssetServerBase.cs
index 5c902ec..7bb2ab9 100644
--- a/OpenSim/Framework/Communications/Cache/AssetServerBase.cs
+++ b/OpenSim/Framework/Communications/Cache/AssetServerBase.cs
@@ -46,6 +46,61 @@ namespace OpenSim.Framework.Communications.Cache
         protected Thread m_localAssetServerThread;
         protected IAssetDataPlugin m_assetProvider;
 
+        #region IPlugin
+ 
+        /// <summary> 
+        /// The methods and properties in this region are needed to implement
+        /// the IPlugin interface and its local extensions.
+        /// These can all be overridden as appropriate by a derived class.
+        /// These methods are only applicable when a class is loaded by the
+        /// IPlugin mechanism.
+        ///
+        /// Note that in the case of AssetServerBase, all initialization is
+        /// performed by the default constructor, so nothing additional is
+        /// required here. A derived class may wish to do more.
+        /// </summary>
+
+        public virtual string Name
+        {
+            // get { return "OpenSim.Framework.Communications.Cache.AssetServerBase"; }
+            get { return "AssetServerBase"; }
+        }
+
+        public virtual string Version
+        {
+            get { return "1.0"; }
+        }
+
+        public virtual void Initialise()
+        {
+            m_log.Debug("[ASSET SERVER]: IPlugin null initialization");
+        }
+
+        public virtual void Initialise(ConfigSettings settings)
+        {
+            m_log.Debug("[ASSET SERVER]: IPlugin null configured initialization(1)");
+            m_log.InfoFormat("[ASSET SERVER]: Initializing client [{0}/{1}", Name, Version);
+        }
+
+        public virtual void Initialise(ConfigSettings settings, string p_url)
+        {
+            m_log.Debug("[ASSET SERVER]: IPlugin null configured initialization(2)");
+            m_log.InfoFormat("[ASSET SERVER]: Initializing client [{0}/{1}", Name, Version);
+        }
+
+        public virtual void Initialise(ConfigSettings settings, string p_url, string p_dir, bool p_t)
+        {
+            m_log.Debug("[ASSET SERVER]: IPlugin null configured initialization(3)");
+            m_log.InfoFormat("[ASSET SERVER]: Initializing client [{0}/{1}", Name, Version);
+        }
+
+        public virtual void Dispose()
+        {
+            m_log.Debug("[ASSET SERVER]: dispose");
+        }
+
+        #endregion
+
         public IAssetDataPlugin AssetProviderPlugin
         {
             get { return m_assetProvider; }
diff --git a/OpenSim/Framework/Communications/Cache/CryptoGridAssetClient.cs b/OpenSim/Framework/Communications/Cache/CryptoGridAssetClient.cs
index 55db289..0f4e8ac 100644
--- a/OpenSim/Framework/Communications/Cache/CryptoGridAssetClient.cs
+++ b/OpenSim/Framework/Communications/Cache/CryptoGridAssetClient.cs
@@ -44,9 +44,37 @@ namespace OpenSim.Framework.Communications.Cache
 {
     public class CryptoGridAssetClient : AssetServerBase
     {
+
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        private string      _assetServerUrl;
+        private bool        m_encryptOnUpload;
+        private RjinKeyfile m_encryptKey;
+        private readonly Dictionary<string,RjinKeyfile> m_keyfiles = new Dictionary<string, RjinKeyfile>();
+
+        #region IPlugin
+
+        public override string Name
+        {
+            get { return "Crypto"; }
+        }
+
+        public override string Version
+        {
+            get { return "1.0"; }
+        }
+
+        public override void Initialise(ConfigSettings p_set, string p_url, string p_dir, bool p_t)
+        {
+            m_log.Debug("[CRYPTOGRID] Plugin configured initialisation");
+            Initialise(p_url, p_dir, p_t);
+        }
+
+        #endregion
+
         #region Keyfile Classes
         [Serializable]
-        private class RjinKeyfile
+        public class RjinKeyfile
         {
             public string Secret;
             public string AlsoKnownAs;
@@ -94,7 +122,7 @@ namespace OpenSim.Framework.Communications.Cache
         /// this may not be the most efficient way of handling encryption, so - as
         /// soon as you feel comfortable with it - you may want to redesign this class.
         /// </summary>
-        private class UtilRijndael
+        public class UtilRijndael
         {
             /// <summary>
             /// Encrypts specified plaintext using Rijndael symmetric key algorithm
@@ -332,15 +360,19 @@ namespace OpenSim.Framework.Communications.Cache
         }
         #endregion
 
-        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
-
-        private readonly string _assetServerUrl;
-        private readonly bool m_encryptOnUpload;
-        private readonly RjinKeyfile m_encryptKey;
-        private readonly Dictionary<string,RjinKeyfile> m_keyfiles = new Dictionary<string, RjinKeyfile>();
+        public CryptoGridAssetClient() {}
 
         public CryptoGridAssetClient(string serverUrl, string keydir, bool decOnly)
         {
+            m_log.Debug("[CRYPTOGRID] Direct constructor");
+            Initialise(serverUrl, keydir, decOnly);
+        }
+
+        public void Initialise(string serverUrl, string keydir, bool decOnly)
+        {
+
+            m_log.Debug("[CRYPTOGRID] Common constructor");
+
             _assetServerUrl = serverUrl;
 
             string[] keys = Directory.GetFiles(keydir, "*.deckey");
diff --git a/OpenSim/Framework/Communications/Cache/FileAssetClient.cs b/OpenSim/Framework/Communications/Cache/FileAssetClient.cs
index 9a60b53..e6574a1 100644
--- a/OpenSim/Framework/Communications/Cache/FileAssetClient.cs
+++ b/OpenSim/Framework/Communications/Cache/FileAssetClient.cs
@@ -26,16 +26,49 @@
  */
 
 using System.IO;
+using System.Reflection;
+using log4net;
 using System.Xml.Serialization;
 
 namespace OpenSim.Framework.Communications.Cache
 {
     public class FileAssetClient : AssetServerBase
     {
-        private readonly string m_dir;
+
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        #region IPlugin
+
+        public override string Name
+        {
+            get { return "File"; }
+        }
+
+        public override string Version
+        {
+            get { return "1.0"; }
+        }
+
+        public override void Initialise(ConfigSettings p_set, string p_url)
+        {
+            m_log.Debug("[FILEASSET] Plugin configured initialisation");
+            Initialise(p_url);
+        }
+
+        #endregion
+
+        private string m_dir;
         private readonly XmlSerializer m_xs = new XmlSerializer(typeof(AssetBase));
 
-        public FileAssetClient(string dir)
+        public FileAssetClient() {}
+
+        public FileAssetClient(string p_url)
+        {
+            m_log.Debug("[FILEASSET] Direct constructor");
+            Initialise(p_url);
+        }
+
+        public void Initialise(string dir)
         {
             if (!Directory.Exists(dir))
             {
diff --git a/OpenSim/Framework/Communications/Cache/GridAssetClient.cs b/OpenSim/Framework/Communications/Cache/GridAssetClient.cs
index 1cc9833..6522ad0 100644
--- a/OpenSim/Framework/Communications/Cache/GridAssetClient.cs
+++ b/OpenSim/Framework/Communications/Cache/GridAssetClient.cs
@@ -36,11 +36,40 @@ namespace OpenSim.Framework.Communications.Cache
 {
     public class GridAssetClient : AssetServerBase
     {
+
+        #region IPlugin
+
+        public override string Name
+        {
+            get { return "Grid"; }
+        }
+
+        public override string Version
+        {
+            get { return "1.0"; }
+        }
+
+        public override void Initialise(ConfigSettings p_set, string p_url)
+        {
+            m_log.Debug("[GRIDASSET] Plugin configured initialisation");
+            Initialise(p_url);
+        }
+
+        #endregion
+
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
 
         private string _assetServerUrl;
 
-        public GridAssetClient(string serverUrl)
+        public GridAssetClient() {}
+
+        public GridAssetClient(string p_url)
+        {
+            m_log.Debug("[GRIDASSET] Direct constructor");
+            Initialise(p_url);
+        }
+
+        public void Initialise(string serverUrl)
         {
             _assetServerUrl = serverUrl;
         }
diff --git a/OpenSim/Framework/Communications/Cache/SQLAssetServer.cs b/OpenSim/Framework/Communications/Cache/SQLAssetServer.cs
index 6266bf0..5274288 100644
--- a/OpenSim/Framework/Communications/Cache/SQLAssetServer.cs
+++ b/OpenSim/Framework/Communications/Cache/SQLAssetServer.cs
@@ -34,10 +34,39 @@ namespace OpenSim.Framework.Communications.Cache
 {
     public class SQLAssetServer : AssetServerBase
     {
+
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
 
+        #region IPlugin
+
+        public override string Name
+        {
+            get { return "SQL"; }
+        }
+
+        public override string Version
+        {
+            get { return "1.0"; }
+        }
+
+        public override void Initialise(ConfigSettings p_set)
+        {
+            m_log.Debug("[SQLASSET] Plugin configured initialisation");
+            Initialise(p_set.StandaloneAssetPlugin,p_set.StandaloneAssetSource);
+        }
+
+        #endregion
+
+        public SQLAssetServer() {}
+
         public SQLAssetServer(string pluginName, string connect)
         {
+            m_log.Debug("[SQLASSET] Direct constructor");
+            Initialise(pluginName, connect);
+        }
+
+        public void Initialise(string pluginName, string connect)
+        {
             AddPlugin(pluginName, connect);
         }
 
diff --git a/OpenSim/Framework/Communications/Resources/AssetCache.addin.xml b/OpenSim/Framework/Communications/Resources/AssetCache.addin.xml
new file mode 100644
index 0000000..61a9f0f
--- /dev/null
+++ b/OpenSim/Framework/Communications/Resources/AssetCache.addin.xml
@@ -0,0 +1,17 @@
+<Addin id="OpenSim.Framework.Communications" version="1.0">
+    <Runtime>
+        <Import assembly="OpenSim.Framework.Communications.dll"/>
+    </Runtime>
+    <Dependencies>
+        <Addin id="OpenSim" version="0.5" />
+    </Dependencies>
+    <Extension path="/OpenSim/AssetCache">
+        <Cache id="Default" provider="Default" type="OpenSim.Framework.Communications.Cache.AssetCache" />
+    </Extension>
+    <Extension path="/OpenSim/AssetServerClient">
+        <ServerClient id="Crypto" provider="Crypto" type="OpenSim.Framework.Communications.Cache.CryptoGridAssetClient" />
+        <ServerClient id="Grid"   provider="Grid"   type="OpenSim.Framework.Communications.Cache.GridAssetClient" />
+        <ServerClient id="File"   provider="File"   type="OpenSim.Framework.Communications.Cache.FileAssetClient" />
+        <ServerClient id="SQL"    provider="SQL"    type="OpenSim.Framework.Communications.Cache.SQLAssetServer" />
+    </Extension>
+</Addin>
diff --git a/OpenSim/Framework/ConfigSettings.cs b/OpenSim/Framework/ConfigSettings.cs
index 3d66311..5f5e16f 100644
--- a/OpenSim/Framework/ConfigSettings.cs
+++ b/OpenSim/Framework/ConfigSettings.cs
@@ -156,6 +156,14 @@ namespace OpenSim.Framework
             set { m_assetStorage = value; }
         }
 
+        private string m_assetCache;
+
+        public string AssetCache
+        {
+            get { return m_assetCache; }
+            set { m_assetCache = value; }
+        }
+
         protected string m_storageConnectionString;
 
         public string StorageConnectionString
diff --git a/OpenSim/Framework/IAssetCache.cs b/OpenSim/Framework/IAssetCache.cs
index b90dffc..22f5755 100644
--- a/OpenSim/Framework/IAssetCache.cs
+++ b/OpenSim/Framework/IAssetCache.cs
@@ -33,7 +33,7 @@ namespace OpenSim.Framework
 
     public delegate void AssetRequestCallback(UUID assetId, AssetBase asset);
 
-    public interface IAssetCache : IAssetReceiver
+    public interface IAssetCache : IAssetReceiver, IPlugin
     {
 
         IAssetServer AssetServer { get; }
@@ -47,5 +47,25 @@ namespace OpenSim.Framework
         void ExpireAsset(UUID assetID);
         void AddAssetRequest(IClientAPI userInfo, TransferRequestPacket transferRequest);
 
+        void Initialise(ConfigSettings cs, IAssetServer server);
+
+    }
+
+    public class AssetCachePluginInitialiser : PluginInitialiserBase
+    {
+        private ConfigSettings config;
+        private IAssetServer   server;
+
+        public AssetCachePluginInitialiser (ConfigSettings p_sv, IAssetServer p_as)
+        {
+            config = p_sv;
+            server = p_as;
+        }
+        public override void Initialise (IPlugin plugin)
+        {
+            IAssetCache p = plugin as IAssetCache;
+            p.Initialise (config, server);
+        }
     }
+
 }
diff --git a/OpenSim/Framework/IAssetServer.cs b/OpenSim/Framework/IAssetServer.cs
index d2f5ce7..0d9afe9 100644
--- a/OpenSim/Framework/IAssetServer.cs
+++ b/OpenSim/Framework/IAssetServer.cs
@@ -32,8 +32,11 @@ namespace OpenSim.Framework
     /// <summary>
     /// Description of IAssetServer.
     /// </summary>
-    public interface IAssetServer
+    public interface IAssetServer : IPlugin
     {
+        void Initialise(ConfigSettings settings);
+        void Initialise(ConfigSettings settings, string url, string dir, bool test);
+        void Initialise(ConfigSettings settings, string url);
         void SetReceiver(IAssetReceiver receiver);
         void RequestAsset(UUID assetID, bool isTexture);
         void StoreAsset(AssetBase asset);
@@ -62,8 +65,62 @@ namespace OpenSim.Framework
         void AssetNotFound(UUID assetID, bool IsTexture);
     }
 
+    public class AssetServerClientPluginInitialiser : PluginInitialiserBase
+    {
+        private ConfigSettings config;
+
+        public AssetServerClientPluginInitialiser (ConfigSettings p_sv)
+        {
+            config = p_sv;
+        }
+        public override void Initialise (IPlugin plugin)
+        {
+            IAssetServer p = plugin as IAssetServer;
+            p.Initialise (config);
+        }
+    }
+
+    public class LegacyAssetServerClientPluginInitialiser : PluginInitialiserBase
+    {
+        private ConfigSettings config;
+        private string assetURL;
+
+        public LegacyAssetServerClientPluginInitialiser (ConfigSettings p_sv, string p_url)
+        {
+            config   = p_sv;
+            assetURL = p_url;
+        }
+        public override void Initialise (IPlugin plugin)
+        {
+            IAssetServer p = plugin as IAssetServer;
+            p.Initialise (config, assetURL);
+        }
+    }
+
+    public class CryptoAssetServerClientPluginInitialiser : PluginInitialiserBase
+    {
+        private ConfigSettings config;
+        private string assetURL;
+        private string currdir;
+        private bool   test;
+
+        public CryptoAssetServerClientPluginInitialiser (ConfigSettings p_sv, string p_url, string p_dir, bool p_test)
+        {
+            config   = p_sv;
+            assetURL = p_url;
+            currdir  = p_dir;
+            test     = p_test;
+        }
+        public override void Initialise (IPlugin plugin)
+        {
+            IAssetServer p = plugin as IAssetServer;
+            p.Initialise (config, assetURL, currdir, test);
+        }
+    }
+
     public interface IAssetPlugin
     {
         IAssetServer GetAssetServer();
     }
+
 }
diff --git a/OpenSim/Region/Application/ConfigurationLoader.cs b/OpenSim/Region/Application/ConfigurationLoader.cs
index 228c0aa..638125c 100644
--- a/OpenSim/Region/Application/ConfigurationLoader.cs
+++ b/OpenSim/Region/Application/ConfigurationLoader.cs
@@ -268,6 +268,7 @@ namespace OpenSim
                 m_configSettings.StorageConnectionString = startupConfig.GetString("storage_connection_string");
                 m_configSettings.EstateConnectionString = startupConfig.GetString("estate_connection_string", m_configSettings.StorageConnectionString);
                 m_configSettings.AssetStorage = startupConfig.GetString("asset_database");
+                m_configSettings.AssetCache = startupConfig.GetString("AssetCache");
                 m_configSettings.ClientstackDll = startupConfig.GetString("clientstack_plugin");
             }
 
diff --git a/OpenSim/Region/Application/OpenSimBase.cs b/OpenSim/Region/Application/OpenSimBase.cs
index 914bd7e..8198138 100644
--- a/OpenSim/Region/Application/OpenSimBase.cs
+++ b/OpenSim/Region/Application/OpenSimBase.cs
@@ -55,6 +55,12 @@ namespace OpenSim
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
 
+        // These are the names of the plugin-points extended by this
+        // class during system startup.
+
+        private const string PLUGIN_ASSET_CACHE         = "/OpenSim/AssetCache";
+        private const string PLUGIN_ASSET_SERVER_CLIENT = "/OpenSim/AssetServerClient";
+
         protected string proxyUrl;
         protected int proxyOffset = 0;                
 
@@ -309,57 +315,183 @@ namespace OpenSim
         }
 
         /// <summary>
-        /// Initialises the assetcache
+        /// Initialises the asset cache. This supports legacy configuration values
+        /// to ensure consistent operation, but values outside of that namespace
+        /// are handled by the more generic resolution mechanism provided by 
+        /// the ResolveAssetServer virtual method. If extended resolution fails, 
+        /// then the normal default action is taken.
+        /// Creation of the AssetCache is handled by ResolveAssetCache. This
+        /// function accepts a reference to the instantiated AssetServer and
+        /// returns an IAssetCache implementation, if possible. This is a virtual
+        /// method.
         /// </summary>
+
         protected virtual void InitialiseAssetCache()
         {
 
+            LegacyAssetServerClientPluginInitialiser linit = null;
+            CryptoAssetServerClientPluginInitialiser cinit = null;
+            AssetServerClientPluginInitialiser        init = null;
+
             IAssetServer assetServer = null;
             string mode = m_configSettings.AssetStorage;
 
-            if (m_configSettings.Standalone   == false &&
-                m_configSettings.AssetStorage == "default")
-                    mode = "grid";
+           if (mode == null | mode == String.Empty)
+                mode = "default";
 
-            switch (mode)
+            // If "default" is specified, then the value is adjusted
+            // according to whether or not the server is running in
+            // standalone mode.
+
+            if (mode.ToLower()  == "default")
             {
+                if (m_configSettings.Standalone == false)
+                        mode = "grid";
+                else
+                        mode = "local";
+            }
+
+            switch (mode.ToLower())
+            {
+
+                // If grid is specified then the grid server is chose regardless 
+                // of whether the server is standalone.
+
                 case "grid" :
-                    assetServer = new GridAssetClient(m_networkServersInfo.AssetURL);
+                    linit = new LegacyAssetServerClientPluginInitialiser(m_configSettings, m_networkServersInfo.AssetURL);
+                    assetServer = loadAssetServer("Grid", linit);
                     break;
+
+
+                // If cryptogrid is specified then the cryptogrid server is chose regardless 
+                // of whether the server is standalone.
+
                 case "cryptogrid" :
-                    assetServer = new CryptoGridAssetClient(m_networkServersInfo.AssetURL,
+                    cinit = new CryptoAssetServerClientPluginInitialiser(m_configSettings, m_networkServersInfo.AssetURL,
                                                         Environment.CurrentDirectory, true);
+                    assetServer = loadAssetServer("Crypto", cinit);
                     break;
+
+                // If cryptogrid_eou is specified then the cryptogrid_eou server is chose regardless 
+                // of whether the server is standalone.
+
                 case "cryptogrid_eou" :
-                    assetServer = new CryptoGridAssetClient(m_networkServersInfo.AssetURL,
+                    cinit = new CryptoAssetServerClientPluginInitialiser(m_configSettings, m_networkServersInfo.AssetURL,
                                                         Environment.CurrentDirectory, false);
+                    assetServer = loadAssetServer("Crypto", cinit);
                     break;
+
+                // If file is specified then the file server is chose regardless 
+                // of whether the server is standalone.
+
                 case "file" :
-                    assetServer = new FileAssetClient(m_networkServersInfo.AssetURL);
+                    linit = new LegacyAssetServerClientPluginInitialiser(m_configSettings, m_networkServersInfo.AssetURL);
+                    assetServer = loadAssetServer("File", linit);
+                    break;
+
+                // If local is specified then we're going to use the local SQL server
+                // implementation. We drop through, because that will be the fallback
+                // for the following default clause too.
+
+                case "local" :
                     break;
+
+                // If the asset_database value is none of the previously mentioned strings, then we
+                // try to load a turnkey plugin that matches this value. If not we drop through to 
+                // a local default.
+
                 default :
-                    if (!ResolveAssetServer(out assetServer))
+                    try
                     {
-                        SQLAssetServer sqlAssetServer = new SQLAssetServer(m_configSettings.StandaloneAssetPlugin, m_configSettings.StandaloneAssetSource);
-                        sqlAssetServer.LoadDefaultAssets(m_configSettings.AssetSetsXMLFile);
-                        assetServer = sqlAssetServer;
+                        init = new AssetServerClientPluginInitialiser(m_configSettings);
+                        assetServer = loadAssetServer(m_configSettings.AssetStorage, init);
+                        break;
                     }
+                    catch {}
+                    m_log.Info("[OPENSIMBASE] Default assetserver will be used");
                     break;
+
+            }
+
+            // Open the local SQL-based database asset server
+
+           if (assetServer == null)
+            {
+                init = new AssetServerClientPluginInitialiser(m_configSettings);
+                SQLAssetServer sqlAssetServer = (SQLAssetServer) loadAssetServer("SQL", init);
+                sqlAssetServer.LoadDefaultAssets(m_configSettings.AssetSetsXMLFile);
+                assetServer = sqlAssetServer;
             }
 
+            // Initialize the asset cache, passing a reference to the selected
+            // asset server interface.
+
             m_assetCache = ResolveAssetCache(assetServer);
 
         }
 
-        private bool ResolveAssetServer(out IAssetServer assetServer)
+        // This method loads the identified asset server, passing an approrpiately
+        // initialized Initialise wrapper. There should to be exactly one match,
+        // if not, then the first match is used.
+
+        private IAssetServer loadAssetServer(string id, PluginInitialiserBase pi)
         {
-            assetServer = null;
-            return false;
+
+            m_log.DebugFormat("[OPENSIMBASE] Attempting to load asset server id={0}", id);
+
+            PluginLoader<IAssetServer> loader = new PluginLoader<IAssetServer>(pi);
+            loader.AddFilter(PLUGIN_ASSET_SERVER_CLIENT, new PluginProviderFilter(id));
+            loader.Load(PLUGIN_ASSET_SERVER_CLIENT);
+           if (loader.Plugins.Count > 0)
+                return (IAssetServer) loader.Plugins[0];
+            else
+                return null;
+
         }
 
-        private IAssetCache ResolveAssetCache(IAssetServer assetServer)
+        /// <summary>
+        /// Attempt to instantiate an IAssetCache implementation, using the
+        /// provided IAssetServer reference.
+        /// An asset cache implementation must provide a constructor that
+        /// accepts two parameters;
+        ///   [1] A ConfigSettings reference.
+        ///   [2] An IAssetServer reference.
+        /// The AssetCache value is obtained from the 
+        /// [StartUp]/AssetCache value in the configuration file.
+        /// </summary>
+
+        protected virtual IAssetCache ResolveAssetCache(IAssetServer assetServer)
         {
-            return new AssetCache(assetServer);
+
+            IAssetCache assetCache = null;
+
+            m_log.DebugFormat("[OPENSIMBASE] Attempting to load asset cache id={0}", m_configSettings.AssetCache);
+
+            if (m_configSettings.AssetCache != null && m_configSettings.AssetCache != String.Empty)
+            {
+                try
+                {
+
+                    PluginInitialiserBase init = new AssetCachePluginInitialiser(m_configSettings, assetServer);
+                    PluginLoader<IAssetCache> loader = new PluginLoader<IAssetCache>(init);
+                    loader.AddFilter(PLUGIN_ASSET_SERVER_CLIENT, new PluginProviderFilter(m_configSettings.AssetCache));
+
+                    loader.Load(PLUGIN_ASSET_CACHE);
+                   if (loader.Plugins.Count > 0)
+                        assetCache = (IAssetCache) loader.Plugins[0];
+     
+                }
+                catch (Exception e)
+                {
+                    m_log.Debug("[OPENSIMBASE] ResolveAssetCache completed");
+                    m_log.Debug(e);
+                }
+            }
+
+            // If everything else fails, we force load the built-in asset cache
+
+            return (IAssetCache) ((assetCache != null) ? assetCache : new AssetCache(assetServer));
+
         }
 
         public void ProcessLogin(bool LoginEnabled)