Thanks, sempuki, for a patch that moves all grid plugins to new PluginLoader (issue 1763).

16 files changed, 314 insertions, 208 deletions

diff --git a/OpenSim/Data/GridDataBase.cs b/OpenSim/Data/GridDataBase.cs
index 0c9d24a..6480f84 100644
--- a/OpenSim/Data/GridDataBase.cs
+++ b/OpenSim/Data/GridDataBase.cs
@@ -29,19 +29,21 @@ using libsecondlife;
 
 namespace OpenSim.Data
 {
-    public abstract class GridDataBase : IGridData
+    public abstract class GridDataBase : IGridDataPlugin
     {
         public abstract RegionProfileData GetProfileByHandle(ulong regionHandle);
         public abstract RegionProfileData GetProfileByLLUUID(LLUUID UUID);
         public abstract RegionProfileData GetProfileByString(string regionName);
         public abstract RegionProfileData[] GetProfilesInRange(uint Xmin, uint Ymin, uint Xmax, uint Ymax);
         public abstract bool AuthenticateSim(LLUUID UUID, ulong regionHandle, string simrecvkey);
-        public abstract void Initialise(string connect);
-        public abstract void Close();
-        public abstract string getName();
-        public abstract string getVersion();
         public abstract DataResponse AddProfile(RegionProfileData profile);
         public abstract ReservationData GetReservationAtPoint(uint x, uint y);
         public abstract DataResponse UpdateProfile(RegionProfileData profile);
+        
+        public abstract void Initialise();
+        public abstract void Initialise(string connect);
+        public abstract void Dispose();
+        public abstract string Name { get; }
+        public abstract string Version { get; }
     }
 }
diff --git a/OpenSim/Data/IGridData.cs b/OpenSim/Data/IGridData.cs
index e242312..fa24d82 100644
--- a/OpenSim/Data/IGridData.cs
+++ b/OpenSim/Data/IGridData.cs
@@ -26,6 +26,10 @@
  */
 
 using libsecondlife;
+using Mono.Addins;
+using OpenSim.Framework;
+
+[assembly : AddinRoot("OpenSim.Data", "0.5")]
 
 namespace OpenSim.Data
 {
@@ -40,9 +44,15 @@ namespace OpenSim.Data
     /// <summary>
     /// A standard grid interface
     /// </summary>
-    public interface IGridData
+    [TypeExtensionPoint("/OpenSim/GridDataStore")]
+    public interface IGridDataPlugin : IPlugin
     {
         /// <summary>
+        /// Initialises the interface
+        /// </summary>
+        void Initialise(string connect);
+        
+        /// <summary>
         /// Returns a sim profile from a regionHandle
         /// </summary>
         /// <param name="regionHandle">A 64bit Region Handle</param>
@@ -84,28 +94,6 @@ namespace OpenSim.Data
         bool AuthenticateSim(LLUUID UUID, ulong regionHandle, string simrecvkey);
 
         /// <summary>
-        /// Initialises the interface
-        /// </summary>
-        void Initialise(string connect);
-
-        /// <summary>
-        /// Closes the interface
-        /// </summary>
-        void Close();
-
-        /// <summary>
-        /// The plugin being loaded
-        /// </summary>
-        /// <returns>A string containing the plugin name</returns>
-        string getName();
-
-        /// <summary>
-        /// The plugins version
-        /// </summary>
-        /// <returns>A string containing the plugin version</returns>
-        string getVersion();
-
-        /// <summary>
         /// Adds a new profile to the database
         /// </summary>
         /// <param name="profile">The profile to add</param>
@@ -116,4 +104,15 @@ namespace OpenSim.Data
 
         ReservationData GetReservationAtPoint(uint x, uint y);
     }
+    
+    public class GridDataStoreInitialiser : PluginInitialiserBase
+    {
+        private string connect;
+        public GridDataStoreInitialiser (string s) { connect = s; }
+        public override void Initialise (IPlugin plugin)
+        {
+            IGridDataPlugin p = plugin as IGridDataPlugin;
+            p.Initialise (connect);
+        }
+    }
 }
diff --git a/OpenSim/Data/ILogData.cs b/OpenSim/Data/ILogData.cs
index 7275637..34657dc 100644
--- a/OpenSim/Data/ILogData.cs
+++ b/OpenSim/Data/ILogData.cs
@@ -25,6 +25,9 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+using Mono.Addins;
+using OpenSim.Framework;
+
 namespace OpenSim.Data
 {
     /// <summary>
@@ -61,7 +64,8 @@ namespace OpenSim.Data
     /// <summary>
     /// An interface to a LogData storage system
     /// </summary>
-    public interface ILogData
+    [TypeExtensionPoint("/OpenSim/GridLogData")]
+    public interface ILogDataPlugin : IPlugin
     {
         void saveLog(string serverDaemon, string target, string methodCall, string arguments, int priority,
                      string logMessage);
@@ -70,22 +74,16 @@ namespace OpenSim.Data
         /// Initialises the interface
         /// </summary>
         void Initialise(string connect);
-
-        /// <summary>
-        /// Closes the interface
-        /// </summary>
-        void Close();
-
-        /// <summary>
-        /// The plugin being loaded
-        /// </summary>
-        /// <returns>A string containing the plugin name</returns>
-        string getName();
-
-        /// <summary>
-        /// The plugins version
-        /// </summary>
-        /// <returns>A string containing the plugin version</returns>
-        string getVersion();
+    }
+    
+    public class LogDataInitialiser : PluginInitialiserBase
+    {
+        private string connect;
+        public LogDataInitialiser (string s) { connect = s; }
+        public override void Initialise (IPlugin plugin)
+        {
+            ILogDataPlugin p = plugin as ILogDataPlugin;
+            p.Initialise (connect);
+        }
     }
 }
diff --git a/OpenSim/Data/MSSQL/MSSQLGridData.cs b/OpenSim/Data/MSSQL/MSSQLGridData.cs
index 0abd0d0..7de77d1 100644
--- a/OpenSim/Data/MSSQL/MSSQLGridData.cs
+++ b/OpenSim/Data/MSSQL/MSSQLGridData.cs
@@ -33,12 +33,18 @@ using System.Security.Cryptography;
 using System.Text;
 using libsecondlife;
 using log4net;
+using Mono.Addins;
+using OpenSim.Framework;
+
+[assembly : Addin]
+[assembly : AddinDependency("OpenSim.Data", "0.5")]
 
 namespace OpenSim.Data.MSSQL
 {
     /// <summary>
     /// A grid data interface for MSSQL Server
     /// </summary>
+    [Extension("/OpenSim/GridDataStore")]
     public class MSSQLGridData : GridDataBase
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
@@ -50,6 +56,12 @@ namespace OpenSim.Data.MSSQL
 
         private string m_regionsTableName;
 
+        override public void Initialise() 
+        { 
+            m_log.Info("[MSSQLGridData]: " + Name + " cannot be default-initialized!");
+            throw new PluginNotInitialisedException (Name);
+        }
+
         /// <summary>
         /// Initialises the Grid Interface
         /// </summary>
@@ -101,7 +113,7 @@ namespace OpenSim.Data.MSSQL
         /// <summary>
         /// Shuts down the grid interface
         /// </summary>
-        override public void Close()
+        override public void Dispose()
         {
             // nothing to close
         }
@@ -110,18 +122,18 @@ namespace OpenSim.Data.MSSQL
         /// The name of this DB provider. 
         /// </summary>
         /// <returns>A string containing the storage system name</returns>
-        override public string getName()
+        override public string Name
         {
-            return "Sql OpenGridData";
+            get { return "Sql OpenGridData"; }
         }
 
         /// <summary>
         /// Database provider version. 
         /// </summary>
         /// <returns>A string containing the storage system version</returns>
-        override public string getVersion()
+        override public string Version
         {
-            return "0.1";
+            get { return "0.1"; }
         }
 
         /// <summary>
diff --git a/OpenSim/Data/MSSQL/MSSQLLogData.cs b/OpenSim/Data/MSSQL/MSSQLLogData.cs
index 849d0fb..d0d81b6 100644
--- a/OpenSim/Data/MSSQL/MSSQLLogData.cs
+++ b/OpenSim/Data/MSSQL/MSSQLLogData.cs
@@ -25,21 +25,39 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+using System;
+using System.Reflection;
 using System.Collections.Generic;
 using System.Data;
+using log4net;
+using Mono.Addins;
+using OpenSim.Framework;
+
+// Only one attribute per assembly. See: *GridData.cs
+// [assembly : Addin]
+// [assembly : AddinDependency("OpenSim.Data", "0.5")]
 
 namespace OpenSim.Data.MSSQL
 {
     /// <summary>
     /// An interface to the log database for MSSQL
     /// </summary>
-    internal class MSSQLLogData : ILogData
+    [Extension("/OpenSim/GridLogData")]
+    internal class MSSQLLogData : ILogDataPlugin
     {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+        
         /// <summary>
         /// The database manager
         /// </summary>
         public MSSQLManager database;
 
+        public void Initialise() 
+        { 
+            m_log.Info("[MSSQLLogData]: " + Name + " cannot be default-initialized!");
+            throw new PluginNotInitialisedException (Name);
+        }
+
         /// <summary>
         /// Artificial constructor called when the plugin is loaded
         /// </summary>
@@ -97,15 +115,15 @@ namespace OpenSim.Data.MSSQL
         /// Returns the name of this DB provider
         /// </summary>
         /// <returns>A string containing the DB provider name</returns>
-        public string getName()
+        public string Name
         {
-            return "MSSQL Logdata Interface";
+            get { return "MSSQL Logdata Interface"; }
         }
 
         /// <summary>
         /// Closes the database provider
         /// </summary>
-        public void Close()
+        public void Dispose()
         {
             // Do nothing.
         }
@@ -114,9 +132,9 @@ namespace OpenSim.Data.MSSQL
         /// Returns the version of this DB provider
         /// </summary>
         /// <returns>A string containing the provider version</returns>
-        public string getVersion()
+        public string Version
         {
-            return "0.1";
+            get { return "0.1"; }
         }
     }
 }
diff --git a/OpenSim/Data/MySQL/MySQLAssetData.cs b/OpenSim/Data/MySQL/MySQLAssetData.cs
index 6cb0b4c..9284ba9 100644
--- a/OpenSim/Data/MySQL/MySQLAssetData.cs
+++ b/OpenSim/Data/MySQL/MySQLAssetData.cs
@@ -34,6 +34,7 @@ using log4net;
 using MySql.Data.MySqlClient;
 using OpenSim.Framework;
 
+
 namespace OpenSim.Data.MySQL
 {
     /// <summary>
diff --git a/OpenSim/Data/MySQL/MySQLGridData.cs b/OpenSim/Data/MySQL/MySQLGridData.cs
index bb71c99..8142c74 100644
--- a/OpenSim/Data/MySQL/MySQLGridData.cs
+++ b/OpenSim/Data/MySQL/MySQLGridData.cs
@@ -33,12 +33,18 @@ using System.Security.Cryptography;
 using System.Text;
 using libsecondlife;
 using log4net;
+using Mono.Addins;
+using OpenSim.Framework;
+
+[assembly : Addin]
+[assembly : AddinDependency("OpenSim.Data", "0.5")]
 
 namespace OpenSim.Data.MySQL
 {
     /// <summary>
     /// A MySQL Interface for the Grid Server
     /// </summary>
+    [Extension("/OpenSim/GridDataStore")]
     public class MySQLGridData : GridDataBase
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
@@ -48,6 +54,12 @@ namespace OpenSim.Data.MySQL
         /// </summary>
         private MySQLManager database;
 
+        override public void Initialise() 
+        { 
+            m_log.Info("[MySQLLogData]: " + Name + " cannot be default-initialized!");
+            throw new PluginNotInitialisedException (Name);
+        }
+
         /// <summary>
         /// <para>Initialises Grid interface</para>
         /// <para>
@@ -144,7 +156,7 @@ namespace OpenSim.Data.MySQL
         /// <summary>
         /// Shuts down the grid interface
         /// </summary>
-        override public void Close()
+        override public void Dispose()
         {
             database.Close();
         }
@@ -153,18 +165,18 @@ namespace OpenSim.Data.MySQL
         /// Returns the plugin name
         /// </summary>
         /// <returns>Plugin name</returns>
-        override public string getName()
+        override public string Name
         {
-            return "MySql OpenGridData";
+            get { return "MySql OpenGridData"; }
         }
 
         /// <summary>
         /// Returns the plugin version
         /// </summary>
         /// <returns>Plugin version</returns>
-        override public string getVersion()
+        override public string Version
         {
-            return "0.1";
+            get { return "0.1"; }
         }
 
         /// <summary>
diff --git a/OpenSim/Data/MySQL/MySQLLogData.cs b/OpenSim/Data/MySQL/MySQLLogData.cs
index fee7f2f..f11aec5 100644
--- a/OpenSim/Data/MySQL/MySQLLogData.cs
+++ b/OpenSim/Data/MySQL/MySQLLogData.cs
@@ -28,20 +28,34 @@ using System;
 using System.Reflection;
 using System.Collections.Generic;
 using log4net;
+using Mono.Addins;
+using OpenSim.Framework;
+
+// Only one attribute per assembly. See: *GridData.cs
+// [assembly : Addin]
+// [assembly : AddinDependency("OpenSim.Data", "0.5")]
 
 namespace OpenSim.Data.MySQL
 {
     /// <summary>
     /// An interface to the log database for MySQL
     /// </summary>
-    internal class MySQLLogData : ILogData
+    [Extension("/OpenSim/GridLogData")]
+    internal class MySQLLogData : ILogDataPlugin
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
         /// <summary>
         /// The database manager
         /// </summary>
         public MySQLManager database;
 
+        public void Initialise() 
+        { 
+            m_log.Info("[MySQLLogData]: " + Name + " cannot be default-initialized!");
+            throw new PluginNotInitialisedException (Name);
+        }
+        
         /// <summary>
         /// Artificial constructor called when the plugin is loaded
         /// Uses the obsolete mysql_connection.ini if connect string is empty.
@@ -128,16 +142,16 @@ namespace OpenSim.Data.MySQL
         /// Returns the name of this DB provider
         /// </summary>
         /// <returns>A string containing the DB provider name</returns>
-        public string getName()
+        public string Name
         {
-            return "MySQL Logdata Interface";
+            get { return "MySQL Logdata Interface";}
         }
 
         /// <summary>
         /// Closes the database provider
         /// </summary>
         /// <remarks>do nothing</remarks>
-        public void Close()
+        public void Dispose()
         {
             // Do nothing.
         }
@@ -146,9 +160,9 @@ namespace OpenSim.Data.MySQL
         /// Returns the version of this DB provider
         /// </summary>
         /// <returns>A string containing the provider version</returns>
-        public string getVersion()
+        public string Version
         {
-            return "0.1";
+            get { return "0.1"; }
         }
     }
 }
diff --git a/OpenSim/Data/MySQL/MySQLManager.cs b/OpenSim/Data/MySQL/MySQLManager.cs
index cf4bce3..89d0672 100644
--- a/OpenSim/Data/MySQL/MySQLManager.cs
+++ b/OpenSim/Data/MySQL/MySQLManager.cs
@@ -227,7 +227,7 @@ namespace OpenSim.Data.MySQL
 
             return
                 string.Format("{0}.{1}.{2}.{3}", dllVersion.Major, dllVersion.Minor, dllVersion.Build,
-                              dllVersion.Revision);
+                        dllVersion.Revision);
         }
 
         /// <summary>
diff --git a/OpenSim/Data/SQLite/SQLiteGridData.cs b/OpenSim/Data/SQLite/SQLiteGridData.cs
index 6fd7235..1e07458 100644
--- a/OpenSim/Data/SQLite/SQLiteGridData.cs
+++ b/OpenSim/Data/SQLite/SQLiteGridData.cs
@@ -28,23 +28,38 @@
 using System;
 using System.Collections.Generic;
 using System.Data;
+using System.Reflection;
 using System.Security.Cryptography;
 using System.Text;
 using libsecondlife;
+using log4net;
+using Mono.Addins;
 using OpenSim.Framework;
 
+[assembly : Addin]
+[assembly : AddinDependency("OpenSim.Data", "0.5")]
+
 namespace OpenSim.Data.SQLite
 {
     /// <summary>
     /// A Grid Interface to the SQLite database
     /// </summary>
+    [Extension("/OpenSim/GridDataStore")]
     public class SQLiteGridData : GridDataBase
     {
+        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
         /// <summary>
         /// SQLite database manager
         /// </summary>
         private SQLiteManager database;
 
+        override public void Initialise() 
+        { 
+            m_log.Info("[SQLite]: " + Name + " cannot be default-initialized!");
+            throw new PluginNotInitialisedException (Name);
+        }
+
         /// <summary>
         /// <list type="bullet">
         /// <item>Initialises Inventory interface</item>
@@ -61,7 +76,7 @@ namespace OpenSim.Data.SQLite
         /// <summary>
         /// Shuts down the grid interface
         /// </summary>
-        override public void Close()
+        override public void Dispose()
         {
             database.Close();
         }
@@ -70,18 +85,18 @@ namespace OpenSim.Data.SQLite
         /// Returns the name of this grid interface
         /// </summary>
         /// <returns>A string containing the grid interface</returns>
-        override public string getName()
+        override public string Name
         {
-            return "SQLite OpenGridData";
+            get { return "SQLite OpenGridData"; }
         }
 
         /// <summary>
         /// Returns the version of this grid interface
         /// </summary>
         /// <returns>A string containing the version</returns>
-        override public string getVersion()
+        override public string Version
         {
-            return "0.1";
+            get { return "0.1"; }
         }
 
         /// <summary>
diff --git a/OpenSim/Framework/PluginLoader.cs b/OpenSim/Framework/PluginLoader.cs
index 9104958..2d61b2c 100644
--- a/OpenSim/Framework/PluginLoader.cs
+++ b/OpenSim/Framework/PluginLoader.cs
@@ -32,6 +32,7 @@ using System.Reflection;
 using log4net;
 using Mono.Addins;
 
+
 namespace OpenSim.Framework
 {
     /// <summary>
@@ -50,8 +51,17 @@ namespace OpenSim.Framework
     /// </summary>
     public interface IPluginConstraint
     {
-        bool Fail (string extpoint);
         string Message { get; }
+        bool Apply (string extpoint);
+    }
+
+    /// <summary>
+    /// Classes wishing to select specific plugins from a range of possible options
+    /// must implement this class and pass it to PluginLoader Load()
+    /// </summary>
+    public interface IPluginFilter
+    {
+        bool Apply (ExtensionNode plugin);
     }
 
     /// <summary>
@@ -64,18 +74,22 @@ namespace OpenSim.Framework
         private List<T> loaded = new List<T>();
         private List<string> extpoints = new List<string>();
         private PluginInitialiserBase initialiser;
+        
         private Dictionary<string,IPluginConstraint> constraints 
             = new Dictionary<string,IPluginConstraint>();
-        
+
+        private Dictionary<string,IPluginFilter> filters 
+            = new Dictionary<string,IPluginFilter>();
+
         private static readonly ILog log 
             = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
-        
+
         public PluginInitialiserBase Initialiser
         { 
             set { initialiser = value; } 
             get { return initialiser; } 
         }
-        
+
         public List<T> Plugins 
         { 
             get { return loaded; } 
@@ -84,25 +98,19 @@ namespace OpenSim.Framework
         public PluginLoader () 
         {
             Initialiser = new PluginInitialiserBase();
+            initialise_plugin_dir_ (".");
         }
 
         public PluginLoader (PluginInitialiserBase init)
         {            
-           Initialiser = init;
+            Initialiser = init;
+            initialise_plugin_dir_ (".");
         }
 
         public PluginLoader (PluginInitialiserBase init, string dir)
         {            
-           Initialiser = init;
-           AddPluginDir (dir);
-        }
-
-        public void AddPluginDir (string dir)
-        {
-            suppress_console_output_ (true);
-            AddinManager.Initialize (dir);
-            AddinManager.Registry.Update (null);            
-            suppress_console_output_ (false);
+            Initialiser = init;
+            initialise_plugin_dir_ (dir);
         }
 
         public void AddExtensionPoint (string extpoint)
@@ -114,50 +122,88 @@ namespace OpenSim.Framework
         {
             constraints.Add (extpoint, cons);
         }
-        
-        public void Load (string extpoint, string dir)
+
+        public void AddFilter (string extpoint, IPluginFilter filter)
+        {
+            filters.Add (extpoint, filter);
+        }
+
+        public void Load (string extpoint)
         {
-            AddPluginDir (dir);
             AddExtensionPoint (extpoint);
             Load();
         }
 
         public void Load ()
         {            
-            suppress_console_output_ (true);
-            AddinManager.Registry.Update (null);            
-            suppress_console_output_ (false);
-
             foreach (string ext in extpoints)
             {
+                log.Info("[PLUGINS]: Loading extension point " + ext);
+
                 if (constraints.ContainsKey (ext))
                 {
                     IPluginConstraint cons = constraints [ext];
-                    if (cons.Fail (ext))
-                        throw new PluginConstraintViolatedException (cons.Message);
+                    if (cons.Apply (ext))
+                        log.Error ("[PLUGINS]: " + ext + " failed constraint: " + cons.Message);
                 }
 
-                ExtensionNodeList ns = AddinManager.GetExtensionNodes (ext);
-                foreach (TypeExtensionNode n in ns)
-                {
-                    T p = (T) n.CreateInstance();
-                    Initialiser.Initialise (p);
-                    Plugins.Add (p);
+                IPluginFilter filter = null;
+                
+                if (filters.ContainsKey (ext))
+                    filter = filters [ext];
 
-                    log.Info("[PLUGINS]: Loading plugin " + n.Path);
+                foreach (TypeExtensionNode node in AddinManager.GetExtensionNodes (ext))
+                {
+                    log.Info("[PLUGINS]: Trying plugin " + node.Path);
+                    
+                    if ((filter != null) && (filter.Apply (node) == false))
+                        continue;
+                        
+                    T plugin = (T) node.CreateInstance();
+                    Initialiser.Initialise (plugin);
+                    Plugins.Add (plugin);
                 }
             }
         }
 
         public void Dispose ()
         {
-            foreach (T p in Plugins)
-                p.Dispose ();
+            foreach (T plugin in Plugins)
+                plugin.Dispose ();
         }
 
-        public void ClearCache()
+        private void initialise_plugin_dir_ (string dir)
         {
-            // The Mono addin manager (in Mono.Addins.dll version 0.2.0.0) occasionally seems to corrupt its addin cache
+            if (AddinManager.IsInitialized == true)
+                return;
+
+            log.Info("[PLUGINS]: Initialzing");
+
+            AddinManager.AddinLoadError += on_addinloaderror_;
+            AddinManager.AddinLoaded += on_addinloaded_;
+
+            clear_registry_();
+
+            suppress_console_output_ (true);
+            AddinManager.Initialize (dir);
+            AddinManager.Registry.Update (null);
+            suppress_console_output_ (false);
+        }
+
+        private void on_addinloaded_(object sender, AddinEventArgs args)
+        {
+            log.Info ("[PLUGINS]: Plugin Loaded: " + args.AddinId);
+        }
+
+        private void on_addinloaderror_(object sender, AddinErrorEventArgs args)
+        {
+            log.Error ("[PLUGINS]: Plugin Error: " + args.Message);
+        }
+
+        private void clear_registry_ ()
+        {
+            // The Mono addin manager (in Mono.Addins.dll version 0.2.0.0) 
+            // occasionally seems to corrupt its addin cache
             // Hence, as a temporary solution we'll remove it before each startup
             if (Directory.Exists("addin-db-000"))
                 Directory.Delete("addin-db-000", true);
@@ -182,6 +228,9 @@ namespace OpenSim.Framework
         }
     }
 
+    /// <summary>
+    /// Constraint that bounds the number of plugins to be loaded.
+    /// </summary>
     public class PluginCountConstraint : IPluginConstraint
     { 
         private int min; 
@@ -208,45 +257,32 @@ namespace OpenSim.Framework
             } 
         }
 
-        public bool Fail (string extpoint)
+        public bool Apply (string extpoint)
         {
-            ExtensionNodeList ns = AddinManager.GetExtensionNodes (extpoint);
-            if ((ns.Count < min) || (ns.Count > max))
-                return true;
-            else
-                return false;
-        }
-    }
+            int count = AddinManager.GetExtensionNodes (extpoint).Count;
 
-    public class PluginFilenameConstraint : IPluginConstraint
-    { 
-        private string filename; 
+            if ((count < min) || (count > max))
+                throw new PluginConstraintViolatedException (Message);
 
-        public PluginFilenameConstraint (string name)
-        { 
-            filename = name; 
-            
-        } 
-
-        public string Message 
-        { 
-            get 
-            { 
-                return "The plugin must have the following name: " + filename; 
-            } 
+            return true;
         }
+    }
+    
+    /// <summary>
+    /// Filters out which plugin to load based on its "Id", which is name given by the namespace or by Mono.Addins.
+    /// </summary>
+    public class PluginIdFilter : IPluginFilter
+    {
+        private string id;
 
-        public bool Fail (string extpoint)
+        public PluginIdFilter (string id) 
         {
-            ExtensionNodeList ns = AddinManager.GetExtensionNodes (extpoint);
-            if (ns.Count != 1)
-                return true;
+            this.id = id;
+        }
 
-            string[] path = ns[0].Path.Split('/');
-            if (path [path.Length-1] == filename)
-                return false;
-                
-            return true;
+        public bool Apply (ExtensionNode plugin)
+        {
+            return (plugin.Id == id);
         }
     }
 }
diff --git a/OpenSim/Grid/GridServer/GridManager.cs b/OpenSim/Grid/GridServer/GridManager.cs
index c539e66..ebc6ac3 100644
--- a/OpenSim/Grid/GridServer/GridManager.cs
+++ b/OpenSim/Grid/GridServer/GridManager.cs
@@ -26,6 +26,7 @@
  */
 
 using System;
+using System.Text;
 using System.Collections;
 using System.Collections.Generic;
 using System.IO;
@@ -46,8 +47,8 @@ namespace OpenSim.Grid.GridServer
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
 
-        private Dictionary<string, IGridData> _plugins = new Dictionary<string, IGridData>();
-        private Dictionary<string, ILogData> _logplugins = new Dictionary<string, ILogData>();
+        private List<IGridDataPlugin> _plugins = new List<IGridDataPlugin>();
+        private List<ILogDataPlugin> _logplugins = new List<ILogDataPlugin>();
 
         // This is here so that the grid server can hand out MessageServer settings to regions on registration
         private List<MessageServerInfo> _MessageServers = new List<MessageServerInfo>();
@@ -57,42 +58,39 @@ namespace OpenSim.Grid.GridServer
         /// <summary>
         /// Adds a new grid server plugin - grid servers will be requested in the order they were loaded.
         /// </summary>
-        /// <param name="FileName">The filename to the grid server plugin DLL</param>
-        public void AddPlugin(string FileName, string Connect)
+        /// <param name="provider">The name of the grid server plugin DLL</param>
+        public void AddPlugin(string provider, string connect)
         {
-            m_log.Info("[DATA]: Attempting to load " + FileName);
-            Assembly pluginAssembly = Assembly.LoadFrom(FileName);
-
-            m_log.Info("[DATA]: Found " + pluginAssembly.GetTypes().Length + " interfaces.");
-            foreach (Type pluginType in pluginAssembly.GetTypes())
-            {
-                if (!pluginType.IsAbstract)
-                {
-                    // Regions go here
-                    Type typeInterface = pluginType.GetInterface("IGridData", true);
-
-                    if (typeInterface != null)
-                    {
-                        IGridData plug =
-                            (IGridData)Activator.CreateInstance(pluginAssembly.GetType(pluginType.ToString()));
-                        plug.Initialise(Connect);
-                        _plugins.Add(plug.getName(), plug);
-                        m_log.Info("[DATA]: Added IGridData Interface");
-                    }
-
-                    // Logs go here
-                    typeInterface = pluginType.GetInterface("ILogData", true);
-
-                    if (typeInterface != null)
-                    {
-                        ILogData plug =
-                            (ILogData)Activator.CreateInstance(pluginAssembly.GetType(pluginType.ToString()));
-                        plug.Initialise(Connect);
-                        _logplugins.Add(plug.getName(), plug);
-                        m_log.Info("[DATA]: Added ILogData Interface");
-                    }
-                }
-            }
+            // FIXME: convert "provider" DLL file name to Mono.Addins "id", 
+            // which unless it is changed in the source code, is the .NET namespace.
+            // In the future, the "provider" should be changed to "id" in the 
+            // config files, and is independent of filenames or namespaces.
+            string[] s = provider.Split ('.');
+            int len = s.Length;
+            if ((len >= 2) && (s [len-1] == "dll"))
+                s [len-1] = s [len-2];
+
+            provider = String.Join (".", s); 
+
+            PluginLoader<IGridDataPlugin> gridloader = 
+                new PluginLoader<IGridDataPlugin> (new GridDataStoreInitialiser (connect));
+
+            PluginLoader<ILogDataPlugin> logloader = 
+                new PluginLoader<ILogDataPlugin> (new LogDataInitialiser (connect));
+
+            gridloader.AddExtensionPoint ("/OpenSim/GridDataStore");
+            logloader.AddExtensionPoint ("/OpenSim/GridLogData");
+            
+            // loader will try to load all providers (MySQL, MSSQL, etc) 
+            // unless it is constrainted to the correct "id"
+            gridloader.AddFilter ("/OpenSim/GridDataStore", new PluginIdFilter (provider + "GridData"));
+            logloader.AddFilter ("/OpenSim/GridLogData", new PluginIdFilter (provider + "LogData"));
+            
+            gridloader.Load();
+            logloader.Load();
+            
+            _plugins = gridloader.Plugins;
+            _logplugins = logloader.Plugins;
         }
 
         /// <summary>
@@ -105,15 +103,15 @@ namespace OpenSim.Grid.GridServer
         /// <param name="message">The message to log</param>
         private void logToDB(string target, string method, string args, int priority, string message)
         {
-            foreach (KeyValuePair<string, ILogData> kvp in _logplugins)
+            foreach (ILogDataPlugin plugin in _logplugins)
             {
                 try
                 {
-                    kvp.Value.saveLog("Gridserver", target, method, args, priority, message);
+                    plugin.saveLog("Gridserver", target, method, args, priority, message);
                 }
                 catch (Exception)
                 {
-                    m_log.Warn("[storage]: Unable to write log via " + kvp.Key);
+                    m_log.Warn("[storage]: Unable to write log via ");
                 }
             }
         }
@@ -125,11 +123,11 @@ namespace OpenSim.Grid.GridServer
         /// <returns>A SimProfileData for the region</returns>
         public RegionProfileData GetRegion(LLUUID uuid)
         {
-            foreach (KeyValuePair<string, IGridData> kvp in _plugins)
+            foreach (IGridDataPlugin plugin in _plugins)
             {
                 try
                 {
-                    return kvp.Value.GetProfileByLLUUID(uuid);
+                    return plugin.GetProfileByLLUUID(uuid);
                 }
                 catch (Exception e)
                 {
@@ -146,15 +144,15 @@ namespace OpenSim.Grid.GridServer
         /// <returns>A SimProfileData for the region</returns>
         public RegionProfileData GetRegion(ulong handle)
         {
-            foreach (KeyValuePair<string, IGridData> kvp in _plugins)
+            foreach (IGridDataPlugin plugin in _plugins)
             {
                 try
                 {
-                    return kvp.Value.GetProfileByHandle(handle);
+                    return plugin.GetProfileByHandle(handle);
                 }
                 catch
                 {
-                    m_log.Warn("[storage]: Unable to find region " + handle.ToString() + " via " + kvp.Key);
+                    m_log.Warn("[storage]: Unable to find region " + handle.ToString() + " via " + plugin.Name);
                 }
             }
             return null;
@@ -167,15 +165,15 @@ namespace OpenSim.Grid.GridServer
         /// <returns>A SimProfileData for the region</returns>
         public RegionProfileData GetRegion(string regionName)
         {
-            foreach (KeyValuePair<string, IGridData> kvp in _plugins)
+            foreach (IGridDataPlugin plugin in _plugins)
             {
                 try
                 {
-                    return kvp.Value.GetProfileByString(regionName);
+                    return plugin.GetProfileByString(regionName);
                 }
                 catch
                 {
-                    m_log.Warn("[storage]: Unable to find region " + regionName + " via " + kvp.Key);
+                    m_log.Warn("[storage]: Unable to find region " + regionName + " via " + plugin.Name);
                 }
             }
             return null;
@@ -185,11 +183,11 @@ namespace OpenSim.Grid.GridServer
         {
             Dictionary<ulong, RegionProfileData> regions = new Dictionary<ulong, RegionProfileData>();
 
-            foreach (KeyValuePair<string, IGridData> kvp in _plugins)
+            foreach (IGridDataPlugin plugin in _plugins)
             {
                 try
                 {
-                    RegionProfileData[] neighbours = kvp.Value.GetProfilesInRange(xmin, ymin, xmax, ymax);
+                    RegionProfileData[] neighbours = plugin.GetProfilesInRange(xmin, ymin, xmax, ymax);
                     foreach (RegionProfileData neighbour in neighbours)
                     {
                         regions[neighbour.regionHandle] = neighbour;
@@ -197,7 +195,7 @@ namespace OpenSim.Grid.GridServer
                 }
                 catch
                 {
-                    m_log.Warn("[storage]: Unable to query regionblock via " + kvp.Key);
+                    m_log.Warn("[storage]: Unable to query regionblock via " + plugin.Name);
                 }
             }
 
@@ -404,7 +402,7 @@ namespace OpenSim.Grid.GridServer
                     return e.XmlRpcErrorResponse;
                 }
 
-                foreach (KeyValuePair<string, IGridData> kvp in _plugins)
+                foreach (IGridDataPlugin plugin in _plugins)
                 {
                     try
                     {
@@ -412,11 +410,11 @@ namespace OpenSim.Grid.GridServer
 
                         if (existingSim == null)
                         {
-                            insertResponse = kvp.Value.AddProfile(sim);
+                            insertResponse = plugin.AddProfile(sim);
                         }
                         else
                         {
-                            insertResponse = kvp.Value.UpdateProfile(sim);
+                            insertResponse = plugin.UpdateProfile(sim);
                         }
 
                         switch (insertResponse)
@@ -441,7 +439,7 @@ namespace OpenSim.Grid.GridServer
                     catch (Exception e)
                     {
                         m_log.Warn("[LOGIN END]: " +
-                                              "Unable to login region " + sim.UUID.ToString() + " via " + kvp.Key);
+                                              "Unable to login region " + sim.UUID.ToString() + " via " + plugin.Name);
                         m_log.Warn("[LOGIN END]: " + e.ToString());
                     }
                 }
@@ -682,12 +680,12 @@ namespace OpenSim.Grid.GridServer
                 return response;
             }
 
-            foreach (KeyValuePair<string, IGridData> kvp in _plugins)
+            foreach (IGridDataPlugin plugin in _plugins)
             {
                 //OpenSim.Data.MySQL.MySQLGridData dbengine = new OpenSim.Data.MySQL.MySQLGridData();
                 try
                 {
-                    MySQLGridData mysqldata = (MySQLGridData)(kvp.Value);
+                    MySQLGridData mysqldata = (MySQLGridData)(plugin);
                     //DataResponse insertResponse = mysqldata.DeleteProfile(TheSim);
                     DataResponse insertResponse = mysqldata.DeleteProfile(uuid);
                     switch (insertResponse)
@@ -1053,17 +1051,17 @@ namespace OpenSim.Grid.GridServer
                 m_log.Info("[DATA]: " +
                            "Updating / adding via " + _plugins.Count + " storage provider(s) registered.");
 
-                foreach (KeyValuePair<string, IGridData> kvp in _plugins)
+                foreach (IGridDataPlugin plugin in _plugins)
                 {
                     try
                     {
                         //Check reservations
                         ReservationData reserveData =
-                            kvp.Value.GetReservationAtPoint(theSim.regionLocX, theSim.regionLocY);
+                            plugin.GetReservationAtPoint(theSim.regionLocX, theSim.regionLocY);
                         if ((reserveData != null && reserveData.gridRecvKey == theSim.regionRecvKey) ||
                             (reserveData == null && authkeynode.InnerText != theSim.regionRecvKey))
                         {
-                            kvp.Value.AddProfile(theSim);
+                            plugin.AddProfile(theSim);
                             m_log.Info("[grid]: New sim added to grid (" + theSim.regionName + ")");
                             logToDB(theSim.UUID.ToString(), "RestSetSimMethod", String.Empty, 5,
                                     "Region successfully updated and connected to grid.");
@@ -1078,7 +1076,7 @@ namespace OpenSim.Grid.GridServer
                     }
                     catch (Exception e)
                     {
-                        m_log.Warn("[GRID]: GetRegionPlugin Handle " + kvp.Key + " unable to add new sim: " +
+                        m_log.Warn("[GRID]: GetRegionPlugin Handle " + plugin.Name + " unable to add new sim: " +
                                                       e.ToString());
                     }
                 }
diff --git a/OpenSim/Grid/GridServer/GridServerBase.cs b/OpenSim/Grid/GridServer/GridServerBase.cs
index 3cd7489..a8ebd27 100644
--- a/OpenSim/Grid/GridServer/GridServerBase.cs
+++ b/OpenSim/Grid/GridServer/GridServerBase.cs
@@ -31,7 +31,6 @@ using System.IO;
 using System.Reflection;
 using System.Timers;
 using log4net;
-using Mono.Addins;
 using OpenSim.Framework;
 using OpenSim.Framework.Console;
 using OpenSim.Framework.Servers;
@@ -121,7 +120,7 @@ namespace OpenSim.Grid.GridServer
             PluginLoader<IGridPlugin> loader = 
                 new PluginLoader<IGridPlugin> (new GridPluginInitialiser (this));
 
-            loader.Load ("/OpenSim/GridServer", ".");
+            loader.Load ("/OpenSim/GridServer");
             m_plugins = loader.Plugins;
         }
 
diff --git a/OpenSim/Grid/GridServer/IGridPlugin.cs b/OpenSim/Grid/GridServer/IGridPlugin.cs
index 6593962..418caec 100644
--- a/OpenSim/Grid/GridServer/IGridPlugin.cs
+++ b/OpenSim/Grid/GridServer/IGridPlugin.cs
@@ -29,7 +29,7 @@
 using Mono.Addins;
 using OpenSim.Framework;
 
-[assembly : AddinRoot("OpenSim", "0.5")]
+[assembly : AddinRoot("OpenSim.Grid.GridServer", "0.5")]
 
 namespace OpenSim.Grid.GridServer
 {
@@ -37,7 +37,6 @@ namespace OpenSim.Grid.GridServer
     public interface IGridPlugin : IPlugin
     {
         void Initialise(GridServerBase gridServer);
-        void Close();
     }
     
     public class GridPluginInitialiser : PluginInitialiserBase
diff --git a/OpenSim/Region/Application/OpenSimBase.cs b/OpenSim/Region/Application/OpenSimBase.cs
index 380df73..910ec55 100644
--- a/OpenSim/Region/Application/OpenSimBase.cs
+++ b/OpenSim/Region/Application/OpenSimBase.cs
@@ -34,7 +34,6 @@ using System.Text;
 using System.Threading;
 using libsecondlife;
 using log4net;
-using Mono.Addins;
 using Nini.Config;
 using OpenSim.Framework;
 using OpenSim.Framework.Communications.Cache;
@@ -338,7 +337,7 @@ namespace OpenSim
             PluginLoader<IApplicationPlugin> loader = 
                 new PluginLoader<IApplicationPlugin> (new ApplicationPluginInitialiser (this));
 
-            loader.Load ("/OpenSim/Startup", ".");
+            loader.Load ("/OpenSim/Startup");
             m_plugins = loader.Plugins;
         }
 
diff --git a/prebuild.xml b/prebuild.xml
index e66f470..97f9394 100644
--- a/prebuild.xml
+++ b/prebuild.xml
@@ -218,6 +218,7 @@
       <Reference name="OpenSim.Framework"/>
       <Reference name="OpenSim.Data.Base"/>
       <Reference name="log4net.dll"/>
+      <Reference name="Mono.Addins.dll" />
       <Files>
         <Match pattern="*.cs" recurse="false"/>
         <Match pattern="Properties/*.cs" recurse="false"/>
@@ -1293,6 +1294,7 @@
       <Reference name="OpenSim.Framework.Console"/>
       <Reference name="OpenSim.Region.Environment"/>
       <Reference name="log4net.dll"/>
+      <Reference name="Mono.Addins.dll" />
 
       <Files>
         <Match pattern="*.cs" recurse="true"/>
@@ -1322,6 +1324,7 @@
       <Reference name="OpenSim.Framework.Console"/>
       <Reference name="libsecondlife.dll"/>
       <Reference name="log4net.dll"/>
+      <Reference name="Mono.Addins.dll" />
 
       <Files>
         <Match pattern="*.cs" recurse="true"/>
@@ -1352,6 +1355,7 @@
       <Reference name="OpenSim.Region.Environment"/>
       <Reference name="libsecondlife.dll"/>
       <Reference name="Mono.Data.SqliteClient"/>
+      <Reference name="Mono.Addins.dll" />
       <Reference name="log4net.dll"/>
 
       <Files>