Update preloading settings

Disable 'preload fast travel' by default.

Add 'min cache size' and 'max cache size' settings.

Split the 'cache expiry delay' into 'preload cell expiry delay' and 'cache expiry delay'.

apps/openmw/mwworld/cellpreloader.cpp

@@ -166,6 +166,8 @@ namespace MWWorld
         , mBulletShapeManager(bulletShapeManager)
         , mTerrain(terrain)
         , mExpiryDelay(0.0)
+        , mMinCacheSize(0)
+        , mMaxCacheSize(0)
     {
     }
 
@@ -197,6 +199,23 @@ namespace MWWorld
             return;
         }
 
+        while (mPreloadCells.size() >= mMaxCacheSize)
+        {
+            // throw out oldest cell to make room
+            PreloadMap::iterator oldestCell = mPreloadCells.begin();
+            double oldestTimestamp = DBL_MAX;
+            for (PreloadMap::iterator it = mPreloadCells.begin(); it != mPreloadCells.end(); ++it)
+            {
+                if (it->second.mTimeStamp < oldestTimestamp)
+                {
+                    oldestTimestamp = it->second.mTimeStamp;
+                    oldestCell = it;
+                }
+            }
+
+            mPreloadCells.erase(oldestCell);
+        }
+
         osg::ref_ptr<PreloadItem> item (new PreloadItem(cell, mResourceSystem->getSceneManager(), mBulletShapeManager, mResourceSystem->getKeyframeManager(), mTerrain));
         mWorkQueue->addWorkItem(item);
 
@@ -210,11 +229,9 @@ namespace MWWorld
 
     void CellPreloader::updateCache(double timestamp)
     {
-        // TODO: add settings for a minimum/maximum size of the cache
-
         for (PreloadMap::iterator it = mPreloadCells.begin(); it != mPreloadCells.end();)
         {
-            if (it->second.mTimeStamp < timestamp - mExpiryDelay)
+            if (mPreloadCells.size() >= mMinCacheSize && it->second.mTimeStamp < timestamp - mExpiryDelay)
                 mPreloadCells.erase(it++);
             else
                 ++it;
@@ -229,6 +246,16 @@ namespace MWWorld
         mExpiryDelay = expiryDelay;
     }
 
+    void CellPreloader::setMinCacheSize(unsigned int num)
+    {
+        mMinCacheSize = num;
+    }
+
+    void CellPreloader::setMaxCacheSize(unsigned int num)
+    {
+        mMaxCacheSize = num;
+    }
+
     void CellPreloader::setWorkQueue(osg::ref_ptr<SceneUtil::WorkQueue> workQueue)
     {
         mWorkQueue = workQueue;

apps/openmw/mwworld/cellpreloader.hpp

@@ -38,6 +38,12 @@ namespace MWWorld
         /// How long to keep a preloaded cell in cache after it's no longer requested.
         void setExpiryDelay(double expiryDelay);
 
+        /// The minimum number of preloaded cells before unused cells get thrown out.
+        void setMinCacheSize(unsigned int num);
+
+        /// The maximum number of preloaded cells.
+        void setMaxCacheSize(unsigned int num);
+
         void setWorkQueue(osg::ref_ptr<SceneUtil::WorkQueue> workQueue);
 
     private:
@@ -46,6 +52,8 @@ namespace MWWorld
         Terrain::World* mTerrain;
         osg::ref_ptr<SceneUtil::WorkQueue> mWorkQueue;
         double mExpiryDelay;
+        unsigned int mMinCacheSize;
+        unsigned int mMaxCacheSize;
 
         struct PreloadEntry
         {

apps/openmw/mwworld/scene.cpp

@@ -463,9 +463,11 @@ namespace MWWorld
 
         mPhysics->setUnrefQueue(rendering.getUnrefQueue());
 
-        float cacheExpiryDelay = Settings::Manager::getFloat("cache expiry delay", "Cells");
-        rendering.getResourceSystem()->setExpiryDelay(cacheExpiryDelay);
-        mPreloader->setExpiryDelay(cacheExpiryDelay);
+        rendering.getResourceSystem()->setExpiryDelay(Settings::Manager::getFloat("cache expiry delay", "Cells"));
+
+        mPreloader->setExpiryDelay(Settings::Manager::getFloat("preload cell expiry delay", "Cells"));
+        mPreloader->setMinCacheSize(Settings::Manager::getInt("preload cell cache min", "Cells"));
+        mPreloader->setMaxCacheSize(Settings::Manager::getInt("preload cell cache max", "Cells"));
     }
 
     Scene::~Scene()

files/settings-default.cfg

@@ -44,7 +44,7 @@ preload enabled = true
 preload exterior grid = true
 
 # Preload possible fast travel destinations.
-preload fast travel = true
+preload fast travel = false
 
 # Preload the locations that doors lead to.
 preload doors = true
@@ -52,9 +52,19 @@ preload doors = true
 # Preloading distance threshold
 preload distance = 1000
 
-# How long to keep preloaded cells and cached models/textures/collision shapes in cache
-# after they're no longer referenced/required (in seconds)
-cache expiry delay = 300
+# The minimum amount of cells in the preload cache before unused cells start to get thrown out (see "preload cell expiry delay").
+# This value should be lower or equal to 'preload cell cache max'.
+preload cell cache min = 12
+
+# The maximum amount of cells in the preload cache. A too high value could cause you to run out of memory.
+# You may need to reduce this setting when running lots of mods or high-res texture replacers.
+preload cell cache max = 20
+
+# How long to keep preloaded cells in cache after they're no longer referenced/required (in seconds)
+preload cell expiry delay = 5
+
+# How long to keep models/textures/collision shapes in cache after they're no longer referenced/required (in seconds)
+cache expiry delay = 5
 
 [Map]