Thank you very much, Xantor for a patch that:

If a request is made for an asset which is not in the cache yet, 
but has already been requested by something else, queue up the 
callbacks on that requester instead of swamping the asset server 
with multiple requests for the same asset. 

1 files changed, 34 insertions, 1 deletions

diff --git a/OpenSim/Framework/Communications/Cache/AssetCache.cs b/OpenSim/Framework/Communications/Cache/AssetCache.cs
index 3ae18f1..feac65a 100644
--- a/OpenSim/Framework/Communications/Cache/AssetCache.cs
+++ b/OpenSim/Framework/Communications/Cache/AssetCache.cs
@@ -248,6 +248,12 @@ namespace OpenSim.Framework.Communications.Cache
         {
             //m_log.DebugFormat("[ASSET CACHE]: Requesting {0} {1}", isTexture ? "texture" : "asset", assetId);
 
+
+            // Xantor 20080526: 
+            // if a request is made for an asset which is not in the cache yet, but has already been requested by
+            // something else, queue up the callbacks on that requestor instead of swamping the assetserver 
+            // with multiple requests for the same asset.
+            
             AssetBase asset;
 
             if (TryGetCachedAsset(assetId, out asset))
@@ -257,9 +263,33 @@ namespace OpenSim.Framework.Communications.Cache
             else
             {
 #if DEBUG
-                //m_log.DebugFormat("[ASSET CACHE]: Adding request for {0} {1}", isTexture ? "texture" : "asset", assetId);
+                // m_log.DebugFormat("[ASSET CACHE]: Adding request for {0} {1}", isTexture ? "texture" : "asset", assetId);
 #endif
+                               
+                
+                NewAssetRequest req = new NewAssetRequest(assetId, callback);
+                AssetRequestsList requestList;
+
+                lock (RequestLists)
+                {
+                    if (RequestLists.TryGetValue(assetId, out requestList)) // do we already have a request pending?
+                    {
+                        // m_log.DebugFormat("[ASSET CACHE]: Intercepted Duplicate request for {0} {1}", isTexture ? "texture" : "asset", assetId);
+                        // add to callbacks for this assetId
+                        RequestLists[assetId].Requests.Add(req);
+                    }
+                    else
+                    {
+                        // m_log.DebugFormat("[ASSET CACHE]: Adding request for {0} {1}", isTexture ? "texture" : "asset", assetId);
+                        requestList = new AssetRequestsList(assetId);
+                        RequestLists.Add(assetId, requestList);
+                        requestList.Requests.Add(req);
+                        m_assetServer.RequestAsset(assetId, isTexture);
+                    }
+                }
+
 
+                /*  Old code doesn't handle duplicate requests right
                 NewAssetRequest req = new NewAssetRequest(assetId, callback);
 
                 // Make sure we always have a request list to which to add the asset
@@ -278,6 +308,7 @@ namespace OpenSim.Framework.Communications.Cache
                 requestList.Requests.Add(req);
 
                 m_assetServer.RequestAsset(assetId, isTexture);
+                */
             }
         }
 
@@ -447,6 +478,8 @@ namespace OpenSim.Framework.Communications.Cache
 
                     foreach (NewAssetRequest req in theseRequests)
                     {
+                        // Xantor 20080526 are we really calling all the callbacks if multiple queued for 1 request? -- Yes, checked
+                        // m_log.DebugFormat("[ASSET CACHE]: Callback for asset {0}", asset.FullID);
                         req.Callback(asset.FullID, asset);
                     }
                 }