From f81be5b4639b6b17d7c8874addd8a7fdb9206663 Mon Sep 17 00:00:00 2001
From: CedricMocquillon <cedric.mocquillon@sage.com>
Date: Thu, 13 May 2021 19:59:28 +0200
Subject: [PATCH] Replace land static container from vector to flat_set

I use a ordered container to fix the "is there any other way to speed this up?".
The flat_set allow to have the same locality when searching an element.
I use the is_transparent C++14 feature to avoid to create a dummy Land when searching
I use a unique_ptr to avoid to manualy manage the memory
---
 apps/openmw/mwworld/store.cpp | 48 +++--------------------------------
 apps/openmw/mwworld/store.hpp | 34 ++++++++++++++++++++++---
 2 files changed, 34 insertions(+), 48 deletions(-)

diff --git a/apps/openmw/mwworld/store.cpp b/apps/openmw/mwworld/store.cpp
index fb66b0a1d7..d2c4725117 100644
--- a/apps/openmw/mwworld/store.cpp
+++ b/apps/openmw/mwworld/store.cpp
@@ -11,25 +11,6 @@
 #include <iterator>
 #include <stdexcept>
 
-namespace
-{
-    struct Compare
-    {
-        bool operator()(const ESM::Land *x, const ESM::Land *y) {
-            if (x->mX == y->mX) {
-                return x->mY < y->mY;
-            }
-            return x->mX < y->mX;
-        }
-        bool operator()(const ESM::Land *x, const std::pair<int, int>& y) {
-            if (x->mX == y.first) {
-                return x->mY < y.second;
-            }
-            return x->mX < y.first;
-        }
-    };
-}
-
 namespace MWWorld
 {
     RecordId::RecordId(const std::string &id, bool isDeleted)
@@ -425,11 +406,6 @@ namespace MWWorld
     //=========================================================================
     Store<ESM::Land>::~Store()
     {
-        for (const ESM::Land* staticLand : mStatic)
-        {
-            delete staticLand;
-        }
-
     }
     size_t Store<ESM::Land>::getSize() const
     {
@@ -446,12 +422,8 @@ namespace MWWorld
     const ESM::Land *Store<ESM::Land>::search(int x, int y) const
     {
         std::pair<int, int> comp(x,y);
-
-        std::vector<ESM::Land *>::const_iterator it =
-            std::lower_bound(mStatic.begin(), mStatic.end(), comp, Compare());
-
-        if (it != mStatic.end() && (*it)->mX == x && (*it)->mY == y) {
-            return *it;
+        if (auto it = mStatic.find(comp); it != mStatic.end() && (*it)->mX == x && (*it)->mY == y) {
+            return it->get();
         }
         return nullptr;
     }
@@ -467,24 +439,13 @@ namespace MWWorld
     }
     RecordId Store<ESM::Land>::load(ESM::ESMReader &esm)
     {
-        ESM::Land *ptr = new ESM::Land();
+        auto ptr = std::make_unique<ESM::Land>();
         bool isDeleted = false;
 
         ptr->load(esm, isDeleted);
 
         // Same area defined in multiple plugins? -> last plugin wins
-        // Can't use search() because we aren't sorted yet - is there any other way to speed this up?
-        for (std::vector<ESM::Land*>::iterator it = mStatic.begin(); it != mStatic.end(); ++it)
-        {
-            if ((*it)->mX == ptr->mX && (*it)->mY == ptr->mY)
-            {
-                delete *it;
-                mStatic.erase(it);
-                break;
-            }
-        }
-
-        mStatic.push_back(ptr);
+        mStatic.insert(std::move(ptr));
 
         return RecordId("", isDeleted);
     }
@@ -494,7 +455,6 @@ namespace MWWorld
         if (mBuilt)
             return;
 
-        std::sort(mStatic.begin(), mStatic.end(), Compare());
         mBuilt = true;
     }
 
diff --git a/apps/openmw/mwworld/store.hpp b/apps/openmw/mwworld/store.hpp
index e37152431e..d65422516a 100644
--- a/apps/openmw/mwworld/store.hpp
+++ b/apps/openmw/mwworld/store.hpp
@@ -3,7 +3,9 @@
 
 #include <string>
 #include <vector>
+#include <memory>
 #include <map>
+#include <boost/container/flat_set.hpp>
 
 #include "recordcmp.hpp"
 
@@ -74,10 +76,10 @@ namespace MWWorld
         const T *find(int index) const;
     };
 
-    template <class T>
+    template <class T, class Container=std::vector<T*>>
     class SharedIterator
     {
-        typedef typename std::vector<T *>::const_iterator Iter;
+        typedef typename Container::const_iterator Iter;
 
         Iter mIter;
 
@@ -233,10 +235,34 @@ namespace MWWorld
     template <>
     class Store<ESM::Land> : public StoreBase
     {
-        std::vector<ESM::Land *> mStatic;
+        struct SpatialComparator
+        {
+            using is_transparent = void;
+
+            bool operator()(const std::unique_ptr<ESM::Land>& x, const std::unique_ptr<ESM::Land>& y) const {
+                if (x->mX == y->mX) {
+                    return x->mY < y->mY;
+                }
+                return x->mX < y->mX;
+            }
+            bool operator()(const std::unique_ptr<ESM::Land>& x, const std::pair<int, int>& y) const {
+                if (x->mX == y.first) {
+                    return x->mY < y.second;
+                }
+                return x->mX < y.first;
+            }
+            bool operator()(const std::pair<int, int>& x, const std::unique_ptr<ESM::Land>& y) const {
+                if (x.first == y->mX) {
+                    return x.second < y->mY;
+                }
+                return x.first < y->mX;
+            }
+        };
+        using Statics = boost::container::flat_set<std::unique_ptr<ESM::Land>, SpatialComparator>;
+        Statics mStatic;
 
     public:
-        typedef SharedIterator<ESM::Land> iterator;
+        typedef SharedIterator<ESM::Land, Statics> iterator;
 
         virtual ~Store();