From: Alan Webb <awebb@linux.vnet.ibm.com>

The change makes two principal implementation changes:

[1] It removes the hard coded set of possible asset server client
implementations, allowing any arbitrary implementation that has been
identified to the PluginLoader as an appropriate extension. The
extension point for asset server client extension
is /OpenSim/AssetServerClient. All of the old configuration rules have
been preserved, and any of the legacy configuration values will still
work as they did before, except the implementation is now loaded as a
plug-in, rather than as a hard-coded instantiation of a specific class.
The re-hashing of IAssetServer as an extension of IPlugin made upgrading
of the implementation classes a necessity.

Caveat: I have not been able to meaningfully test the crypto-grid
clients. I believe they should work correctly, but the refactoring
necessary to handle plug-in based initialization (vs constructor-based
initialisation) admits the possibility of a problem.

[2] The asset cache implementation, previously introduce as a hard-code
class instantiation is now implemented as an IPlugin. Once again the
previous (configurationless) behavior has been preserved. But now it is
possible for those interested in experimenting with cache technologies
to do so simply by introducing a new extension for the asset cache
extension point (/OpenSim/AssetCache).

I've tested all of the configuration settings, after applying the patch
to a newly extracted tree, and they seem to work OK.

1 files changed, 65 insertions, 15 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);