From 89ac0fa232112ee3bf4b61e545b0a823b9ffbfe0 Mon Sep 17 00:00:00 2001
From: Marc Zinnschlag <marc@zpages.de>
Date: Thu, 21 Jun 2012 11:43:18 +0200
Subject: [PATCH] Issue #312: Implemented ID-search caching to speed up some
 badly written scripts

---
 apps/openmw/mwworld/cells.cpp | 42 +++++++++++++++++++++++++++++------
 apps/openmw/mwworld/cells.hpp |  4 ++++
 2 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/apps/openmw/mwworld/cells.cpp b/apps/openmw/mwworld/cells.cpp
index 990a4cc4a3..3d6042e466 100644
--- a/apps/openmw/mwworld/cells.cpp
+++ b/apps/openmw/mwworld/cells.cpp
@@ -70,8 +70,26 @@ void MWWorld::Cells::fillContainers (Ptr::CellStore& cellStore)
     }
 }
 
+MWWorld::Ptr MWWorld::Cells::getPtrAndCache (const std::string& name, Ptr::CellStore& cellStore)
+{
+    Ptr ptr = getPtr (name, cellStore);
+
+    if (!ptr.isEmpty())
+    {
+        mIdCache[mIdCacheIndex].first = name;
+        mIdCache[mIdCacheIndex].second = &cellStore;
+        if (++mIdCacheIndex>=mIdCache.size())
+            mIdCacheIndex = 0;
+    }
+
+    return ptr;
+}
+
 MWWorld::Cells::Cells (const ESMS::ESMStore& store, ESM::ESMReader& reader, MWWorld::World& world)
-: mStore (store), mReader (reader), mWorld (world) {}
+: mStore (store), mReader (reader), mWorld (world),
+  mIdCache (20, std::pair<std::string, Ptr::CellStore *> ("", 0)), /// \todo make cache size configurable
+  mIdCacheIndex (0)
+{}
 
 MWWorld::Ptr::CellStore *MWWorld::Cells::getExterior (int x, int y)
 {
@@ -215,19 +233,29 @@ MWWorld::Ptr MWWorld::Cells::getPtr (const std::string& name, Ptr::CellStore& ce
 
 MWWorld::Ptr MWWorld::Cells::getPtr (const std::string& name)
 {
-    // First check cells that are already listed
+    // First check the cache
+    for (std::vector<std::pair<std::string, Ptr::CellStore *> >::iterator iter (mIdCache.begin());
+        iter!=mIdCache.end(); ++iter)
+        if (iter->first==name && iter->second)
+        {
+            Ptr ptr = getPtr (name, *iter->second);
+            if (!ptr.isEmpty())
+                return ptr;
+        }
+
+    // Then check cells that are already listed
     for (std::map<std::string, Ptr::CellStore>::iterator iter = mInteriors.begin();
         iter!=mInteriors.end(); ++iter)
     {
-        Ptr ptr = getPtr (name, iter->second);
+        Ptr ptr = getPtrAndCache (name, iter->second);
         if (!ptr.isEmpty())
-            return ptr;
+             return ptr;
     }
 
     for (std::map<std::pair<int, int>, Ptr::CellStore>::iterator iter = mExteriors.begin();
         iter!=mExteriors.end(); ++iter)
     {
-        Ptr ptr = getPtr (name, iter->second);
+        Ptr ptr = getPtrAndCache (name, iter->second);
         if (!ptr.isEmpty())
             return ptr;
     }
@@ -238,7 +266,7 @@ MWWorld::Ptr MWWorld::Cells::getPtr (const std::string& name)
     {
         Ptr::CellStore *cellStore = getCellStore (iter->second);
 
-        Ptr ptr = getPtr (name, *cellStore);
+        Ptr ptr = getPtrAndCache (name, *cellStore);
 
         if (!ptr.isEmpty())
             return ptr;
@@ -249,7 +277,7 @@ MWWorld::Ptr MWWorld::Cells::getPtr (const std::string& name)
     {
         Ptr::CellStore *cellStore = getCellStore (iter->second);
 
-        Ptr ptr = getPtr (name, *cellStore);
+        Ptr ptr = getPtrAndCache (name, *cellStore);
 
         if (!ptr.isEmpty())
             return ptr;
diff --git a/apps/openmw/mwworld/cells.hpp b/apps/openmw/mwworld/cells.hpp
index 42aa1050c0..05367138f2 100644
--- a/apps/openmw/mwworld/cells.hpp
+++ b/apps/openmw/mwworld/cells.hpp
@@ -28,6 +28,8 @@ namespace MWWorld
             std::map<std::string, Ptr::CellStore> mInteriors;
             std::map<std::pair<int, int>, Ptr::CellStore> mExteriors;
             MWWorld::World& mWorld;
+            std::vector<std::pair<std::string, Ptr::CellStore *> > mIdCache;
+            std::size_t mIdCacheIndex;
 
             Cells (const Cells&);
             Cells& operator= (const Cells&);
@@ -36,6 +38,8 @@ namespace MWWorld
 
             void fillContainers (Ptr::CellStore& cellStore);
 
+            Ptr getPtrAndCache (const std::string& name, Ptr::CellStore& cellStore);
+
         public:
 
             Cells (const ESMS::ESMStore& store, ESM::ESMReader& reader, MWWorld::World& world);