4 files changed, 144 insertions, 25 deletions

diff --git a/OpenSim/Region/CoreModules/Asset/CenomeAssetCache.cs b/OpenSim/Region/CoreModules/Asset/CenomeAssetCache.cs
index ebec9d2..14b0280 100644
--- a/OpenSim/Region/CoreModules/Asset/CenomeAssetCache.cs
+++ b/OpenSim/Region/CoreModules/Asset/CenomeAssetCache.cs
@@ -91,7 +91,7 @@ namespace OpenSim.Region.CoreModules.Asset
     /// </code>
     /// </example>
     [Extension(Path = "/OpenSim/RegionModules", NodeName = "RegionModule", Id = "CenomeMemoryAssetCache")]
-    public class CenomeMemoryAssetCache : IImprovedAssetCache, ISharedRegionModule
+    public class CenomeMemoryAssetCache : IAssetCache, ISharedRegionModule
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
         
@@ -192,7 +192,7 @@ namespace OpenSim.Region.CoreModules.Asset
                 expirationTime);
         }
 
-        #region IImprovedAssetCache Members
+        #region IAssetCache Members
 
         public bool Check(string id)
         {
@@ -221,6 +221,11 @@ namespace OpenSim.Region.CoreModules.Asset
 
         }
 
+        public void CacheNegative(string id)
+        {
+            // We don't do negative caching
+        }
+
         /// <summary>
         /// Clear asset cache.
         /// </summary>
@@ -308,7 +313,7 @@ namespace OpenSim.Region.CoreModules.Asset
         public void AddRegion(Scene scene)
         {
             if (m_enabled)
-                scene.RegisterModuleInterface<IImprovedAssetCache>(this);
+                scene.RegisterModuleInterface<IAssetCache>(this);
         }
 
         /// <summary>
diff --git a/OpenSim/Region/CoreModules/Asset/CoreAssetCache.cs b/OpenSim/Region/CoreModules/Asset/CoreAssetCache.cs
index f720748..82bc5cc 100644
--- a/OpenSim/Region/CoreModules/Asset/CoreAssetCache.cs
+++ b/OpenSim/Region/CoreModules/Asset/CoreAssetCache.cs
@@ -40,7 +40,7 @@ using OpenSim.Services.Interfaces;
 namespace OpenSim.Region.CoreModules.Asset
 {
     [Extension(Path = "/OpenSim/RegionModules", NodeName = "RegionModule", Id = "CoreAssetCache")]
-    public class CoreAssetCache : ISharedRegionModule, IImprovedAssetCache
+    public class CoreAssetCache : ISharedRegionModule, IAssetCache
     {
         private static readonly ILog m_log =
                 LogManager.GetLogger(
@@ -98,7 +98,7 @@ namespace OpenSim.Region.CoreModules.Asset
         public void AddRegion(Scene scene)
         {
             if (m_Enabled)
-                scene.RegisterModuleInterface<IImprovedAssetCache>(this);
+                scene.RegisterModuleInterface<IAssetCache>(this);
         }
 
         public void RemoveRegion(Scene scene)
@@ -110,7 +110,7 @@ namespace OpenSim.Region.CoreModules.Asset
         }
 
         ////////////////////////////////////////////////////////////
-        // IImprovedAssetCache
+        // IAssetCache
         //
         public bool Check(string id)
         {
@@ -124,6 +124,11 @@ namespace OpenSim.Region.CoreModules.Asset
                 m_Cache.Store(asset.ID, asset);
         }
 
+        public void CacheNegative(string id)
+        {
+            // We don't do negative caching
+        }
+
         public AssetBase Get(string id)
         {
             return (AssetBase)m_Cache.Get(id);
diff --git a/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs b/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs
index b6dd565..84e13a0 100644
--- a/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs
+++ b/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs
@@ -55,7 +55,7 @@ using OpenSim.Services.Interfaces;
 namespace OpenSim.Region.CoreModules.Asset
 {
     [Extension(Path = "/OpenSim/RegionModules", NodeName = "RegionModule", Id = "FlotsamAssetCache")]
-    public class FlotsamAssetCache : ISharedRegionModule, IImprovedAssetCache, IAssetService
+    public class FlotsamAssetCache : ISharedRegionModule, IAssetCache, IAssetService
     {
         private static readonly ILog m_log =
                 LogManager.GetLogger(
@@ -78,6 +78,7 @@ namespace OpenSim.Region.CoreModules.Asset
         private static ulong m_RequestsForInprogress;
         private static ulong m_DiskHits;
         private static ulong m_MemoryHits;
+        private static ulong m_weakRefHits;
 
 #if WAIT_ON_INPROGRESS_REQUESTS
         private Dictionary<string, ManualResetEvent> m_CurrentlyWriting = new Dictionary<string, ManualResetEvent>();
@@ -91,9 +92,15 @@ namespace OpenSim.Region.CoreModules.Asset
         private ExpiringCache<string, AssetBase> m_MemoryCache;
         private bool m_MemoryCacheEnabled = false;
 
+        private ExpiringCache<string, object> m_negativeCache;
+        private bool m_negativeCacheEnabled = true;
+        private bool m_negativeCacheSliding = false;
+
         // Expiration is expressed in hours.
-        private double m_MemoryExpiration = 0.001;
+        private double m_MemoryExpiration = 0.016;
         private const double m_DefaultFileExpiration = 48;
+        // Negative cache is in seconds
+        private int m_negativeExpiration = 120;
         private TimeSpan m_FileExpiration = TimeSpan.FromHours(m_DefaultFileExpiration);
         private TimeSpan m_FileExpirationCleanupTimer = TimeSpan.FromHours(1.0);
 
@@ -107,6 +114,10 @@ namespace OpenSim.Region.CoreModules.Asset
         private List<Scene> m_Scenes = new List<Scene>();
         private object timerLock = new object();
         
+        private Dictionary<string,WeakReference> weakAssetReferences = new Dictionary<string, WeakReference>();
+        private object weakAssetReferencesLock = new object();
+        private bool m_updateFileTimeOnCacheHit = false;
+
         public FlotsamAssetCache()
         {
             m_InvalidChars.AddRange(Path.GetInvalidPathChars());
@@ -134,6 +145,7 @@ namespace OpenSim.Region.CoreModules.Asset
                 if (name == Name)
                 {
                     m_MemoryCache = new ExpiringCache<string, AssetBase>();
+                    m_negativeCache = new ExpiringCache<string, object>();
                     m_Enabled = true;
 
                     m_log.InfoFormat("[FLOTSAM ASSET CACHE]: {0} enabled", this.Name);
@@ -152,6 +164,11 @@ namespace OpenSim.Region.CoreModules.Asset
                         m_MemoryCacheEnabled = assetConfig.GetBoolean("MemoryCacheEnabled", m_MemoryCacheEnabled);
                         m_MemoryExpiration = assetConfig.GetDouble("MemoryCacheTimeout", m_MemoryExpiration);
                         m_MemoryExpiration *= 3600.0; // config in hours to seconds
+
+                        m_negativeCacheEnabled = assetConfig.GetBoolean("NegativeCacheEnabled", m_negativeCacheEnabled);
+                        m_negativeExpiration = assetConfig.GetInt("NegativeCacheTimeout", m_negativeExpiration);
+                        m_negativeCacheSliding = assetConfig.GetBoolean("NegativeCacheSliding", m_negativeCacheSliding);
+                        m_updateFileTimeOnCacheHit = assetConfig.GetBoolean("UpdateFileTimeOnCacheHit", m_updateFileTimeOnCacheHit);
     
     #if WAIT_ON_INPROGRESS_REQUESTS
                         m_WaitOnInprogressTimeout = assetConfig.GetInt("WaitOnInprogressTimeout", 3000);
@@ -212,7 +229,7 @@ namespace OpenSim.Region.CoreModules.Asset
         {
             if (m_Enabled)
             {
-                scene.RegisterModuleInterface<IImprovedAssetCache>(this);
+                scene.RegisterModuleInterface<IAssetCache>(this);
                 m_Scenes.Add(scene);
             }
         }
@@ -221,7 +238,7 @@ namespace OpenSim.Region.CoreModules.Asset
         {
             if (m_Enabled)
             {
-                scene.UnregisterModuleInterface<IImprovedAssetCache>(this);
+                scene.UnregisterModuleInterface<IAssetCache>(this);
                 m_Scenes.Remove(scene);
                 lock(timerLock)
                 {
@@ -255,12 +272,23 @@ namespace OpenSim.Region.CoreModules.Asset
                         }
                     }
                  }
+                if (m_MemoryCacheEnabled)
+                    m_MemoryCache = new ExpiringCache<string, AssetBase>();
+            
+                lock(weakAssetReferencesLock)
+                    weakAssetReferences = new Dictionary<string, WeakReference>();
             }
         }
 
         ////////////////////////////////////////////////////////////
-        // IImprovedAssetCache
+        // IAssetCache
         //
+        private void UpdateWeakReference(string key, AssetBase asset)
+        {
+            WeakReference aref = new WeakReference(asset);
+            lock(weakAssetReferencesLock)
+                weakAssetReferences[key] = aref;
+        }
 
         private void UpdateMemoryCache(string key, AssetBase asset)
         {
@@ -327,6 +355,7 @@ namespace OpenSim.Region.CoreModules.Asset
             if (asset != null)
             {
                 //m_log.DebugFormat("[FLOTSAM ASSET CACHE]: Caching asset with id {0}", asset.ID);
+                UpdateWeakReference(asset.ID, asset);
 
                 if (m_MemoryCacheEnabled)
                     UpdateMemoryCache(asset.ID, asset);
@@ -336,6 +365,17 @@ namespace OpenSim.Region.CoreModules.Asset
             }
         }
 
+        public void CacheNegative(string id)
+        {
+            if (m_negativeCacheEnabled)
+            {
+                if (m_negativeCacheSliding)
+                    m_negativeCache.AddOrUpdate(id, null, TimeSpan.FromSeconds(m_negativeExpiration));
+                else
+                    m_negativeCache.AddOrUpdate(id, null, m_negativeExpiration);
+            }
+        }
+
         /// <summary>
         /// Updates the cached file with the current time.
         /// </summary>
@@ -354,6 +394,25 @@ namespace OpenSim.Region.CoreModules.Asset
             }
         }
 
+        private AssetBase GetFromWeakReference(string id)
+        {
+            AssetBase asset = null;
+            WeakReference aref;
+
+            lock(weakAssetReferencesLock)
+            {
+                if (weakAssetReferences.TryGetValue(id, out aref))
+                {
+                    asset = aref.Target as AssetBase;
+                    if(asset == null)
+                        weakAssetReferences.Remove(id);
+                    else
+                        m_weakRefHits++;
+                }
+            }
+            return asset;
+        }
+
         /// <summary>
         /// Try to get an asset from the in-memory cache.
         /// </summary>
@@ -476,13 +535,38 @@ namespace OpenSim.Region.CoreModules.Asset
         {
             m_Requests++;
 
+            object dummy;
+            if (m_negativeCache.TryGetValue(id, out dummy))
+                return null;
+
             AssetBase asset = null;
+            asset = GetFromWeakReference(id);
+            if (asset != null && m_updateFileTimeOnCacheHit)
+            {
+                string filename = GetFileName(id);
+                UpdateFileLastAccessTime(filename);
+            }
 
-            if (m_MemoryCacheEnabled)
+            if (m_MemoryCacheEnabled && asset == null)
+            {
                 asset = GetFromMemoryCache(id);
+                if(asset != null)
+                {
+                    UpdateWeakReference(id,asset);
+                    if (m_updateFileTimeOnCacheHit)
+                    {
+                        string filename = GetFileName(id);
+                        UpdateFileLastAccessTime(filename);
+                    }
+                }
+            }
 
             if (asset == null && m_FileCacheEnabled)
+            {
                 asset = GetFromFileCache(id);
+                if(asset != null)
+                    UpdateWeakReference(id,asset);
+            }
 
             if (m_MemoryCacheEnabled && asset != null)
                 UpdateMemoryCache(id, asset);
@@ -494,6 +578,12 @@ namespace OpenSim.Region.CoreModules.Asset
                 GenerateCacheHitReport().ForEach(l => m_log.InfoFormat("[FLOTSAM ASSET CACHE]: {0}", l));
             }
 
+            if(asset == null)
+            {
+
+
+            }
+
             return asset;
         }
 
@@ -530,6 +620,9 @@ namespace OpenSim.Region.CoreModules.Asset
 
                 if (m_MemoryCacheEnabled)
                     m_MemoryCache.Remove(id);
+
+                lock(weakAssetReferencesLock)
+                    weakAssetReferences.Remove(id);
             }
             catch (Exception e)
             {
@@ -553,7 +646,12 @@ namespace OpenSim.Region.CoreModules.Asset
             }
 
             if (m_MemoryCacheEnabled)
-                m_MemoryCache.Clear();
+                m_MemoryCache = new ExpiringCache<string, AssetBase>();
+            if (m_negativeCacheEnabled)
+                m_negativeCache = new ExpiringCache<string, object>();
+            
+            lock(weakAssetReferencesLock)
+                weakAssetReferences = new Dictionary<string, WeakReference>();
         }
 
         private void CleanupExpiredFiles(object source, ElapsedEventArgs e)
@@ -911,28 +1009,34 @@ namespace OpenSim.Region.CoreModules.Asset
             List<string> outputLines = new List<string>();
 
             double invReq = 100.0 / m_Requests;
+
+            double weakHitRate = m_weakRefHits * invReq;
+            int weakEntries = weakAssetReferences.Count;
             
             double fileHitRate = m_DiskHits * invReq;
+            double TotalHitRate = weakHitRate + fileHitRate;
+
             outputLines.Add(
-                string.Format("File Hit Rate: {0}% for {1} requests", fileHitRate.ToString("0.00"), m_Requests));
+                string.Format("Total requests: {0}", m_Requests));
+            outputLines.Add(
+                string.Format("unCollected Hit Rate: {0}% ({1} entries)", weakHitRate.ToString("0.00"),weakEntries));
+            outputLines.Add(
+                string.Format("File Hit Rate: {0}%", fileHitRate.ToString("0.00")));
 
             if (m_MemoryCacheEnabled)
             {
                 double HitRate = m_MemoryHits * invReq;
-
                 outputLines.Add(
-                    string.Format("Memory Hit Rate: {0}% for {1} requests", HitRate.ToString("0.00"), m_Requests));
+                    string.Format("Memory Hit Rate: {0}%", HitRate.ToString("0.00")));
 
-                HitRate += fileHitRate;
-
-                outputLines.Add(
-                    string.Format("Total Hit Rate: {0}% for {1} requests", HitRate.ToString("0.00"), m_Requests));
+                TotalHitRate += HitRate;
             }
+            outputLines.Add(
+                string.Format("Total Hit Rate: {0}%", TotalHitRate.ToString("0.00")));
 
             outputLines.Add(
                 string.Format(
-                    "Unnecessary requests due to requests for assets that are currently downloading: {0}", 
-                    m_RequestsForInprogress));
+                    "Requests overlap during file writing: {0}", m_RequestsForInprogress));
 
             return outputLines;
         }
diff --git a/OpenSim/Region/CoreModules/Asset/GlynnTuckerAssetCache.cs b/OpenSim/Region/CoreModules/Asset/GlynnTuckerAssetCache.cs
index 5f76ac2..195bdaa 100644
--- a/OpenSim/Region/CoreModules/Asset/GlynnTuckerAssetCache.cs
+++ b/OpenSim/Region/CoreModules/Asset/GlynnTuckerAssetCache.cs
@@ -41,7 +41,7 @@ using OpenSim.Services.Interfaces;
 namespace OpenSim.Region.CoreModules.Asset
 {
     [Extension(Path = "/OpenSim/RegionModules", NodeName = "RegionModule", Id = "GlynnTuckerAssetCache")]
-    public class GlynnTuckerAssetCache : ISharedRegionModule, IImprovedAssetCache
+    public class GlynnTuckerAssetCache : ISharedRegionModule, IAssetCache
     {
         private static readonly ILog m_log =
                 LogManager.GetLogger(
@@ -100,7 +100,7 @@ namespace OpenSim.Region.CoreModules.Asset
         public void AddRegion(Scene scene)
         {
             if (m_Enabled)
-                scene.RegisterModuleInterface<IImprovedAssetCache>(this);
+                scene.RegisterModuleInterface<IAssetCache>(this);
         }
 
         public void RemoveRegion(Scene scene)
@@ -112,7 +112,7 @@ namespace OpenSim.Region.CoreModules.Asset
         }
 
         ////////////////////////////////////////////////////////////
-        // IImprovedAssetCache
+        // IAssetCache
         //
 
         public bool Check(string id)
@@ -126,6 +126,11 @@ namespace OpenSim.Region.CoreModules.Asset
                 m_Cache.AddOrUpdate(asset.ID, asset);
         }
 
+        public void CacheNegative(string id)
+        {
+            // We don't do negative caching
+        }
+
         public AssetBase Get(string id)
         {
             Object asset = null;