From 2b6a8698c1b979c4ea3130a36eeabaa415bcec36 Mon Sep 17 00:00:00 2001
From: UbitUmarov <ajlduarte@sapo.pt>
Date: Sun, 4 Jul 2021 03:13:43 +0100
Subject: [PATCH] flotsam cache: reduce number of calls to
 File.SetLastAccessTime, (if that option is enabled )

---
 .../CoreModules/Asset/FlotsamAssetCache.cs    | 26 +++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs b/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs
index 6a0d2c6a04..29b047cce6 100755
--- a/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs
+++ b/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs
@@ -115,6 +115,8 @@ namespace OpenSim.Region.CoreModules.Asset
         private readonly object weakAssetReferencesLock = new object();
         private bool m_updateFileTimeOnCacheHit = false;
 
+        private static ExpiringKey<string> m_lastFileAccessTimeChange = null;
+
         public FlotsamAssetCache()
         {
             List<char> invalidChars = new List<char>();
@@ -183,6 +185,9 @@ namespace OpenSim.Region.CoreModules.Asset
                         m_CacheWarnAt = assetConfig.GetInt("CacheWarnAt", m_CacheWarnAt);
                     }
 
+                    if(m_updateFileTimeOnCacheHit)
+                        m_lastFileAccessTimeChange = new ExpiringKey<string>(300000);
+
                     if(m_MemoryCacheEnabled)
                         m_MemoryCache = new ExpiringCacheOS<string, AssetBase>((int)m_MemoryExpiration * 500);
 
@@ -430,11 +435,12 @@ namespace OpenSim.Region.CoreModules.Asset
         /// </summary>
         /// <param name="filename">Filename.</param>
         /// <returns><c>true</c>, if the update was successful, false otherwise.</returns>
-        private static bool UpdateFileLastAccessTime(string filename)
+        private static bool CheckUpdateFileLastAccessTime(string filename)
         {
             try
             {
                 File.SetLastAccessTime(filename, DateTime.Now);
+                m_lastFileAccessTimeChange.Add(filename, 900000);
                 return true;
             }
             catch (FileNotFoundException)
@@ -447,6 +453,21 @@ namespace OpenSim.Region.CoreModules.Asset
             }
         }
 
+        private static void UpdateFileLastAccessTime(string filename)
+        {
+            try
+            {
+                if(!m_lastFileAccessTimeChange.ContainsKey(filename))
+                {
+                    File.SetLastAccessTime(filename, DateTime.Now);
+                    m_lastFileAccessTimeChange.Add(filename, 900000);
+                }
+            }
+            catch
+            {
+            }
+        }
+
         private AssetBase GetFromWeakReference(string id)
         {
             AssetBase asset = null;
@@ -974,6 +995,7 @@ namespace OpenSim.Region.CoreModules.Asset
                         bformatter.Serialize(stream, asset);
                         stream.Flush();
                     }
+                    m_lastFileAccessTimeChange.Add(filename, 900000);
                 }
                 catch (IOException e)
                 {
@@ -1096,7 +1118,7 @@ namespace OpenSim.Region.CoreModules.Asset
                     break;
 
                 string idstr = id.ToString();
-                if (!UpdateFileLastAccessTime(GetFileName(idstr)) && tryGetUncached)
+                if (tryGetUncached && !CheckUpdateFileLastAccessTime(GetFileName(idstr)))
                 {
                     cooldown += 5;
                     m_AssetService.Get(idstr);