[Bf-blender-cvs] [a264dff4fa7] master: BLI: optimize Map/Set/VectorSet.clear methods

[Jacques Lucke]

Commit: a264dff4fa7dd0bb2e3c9abe805376b730d28c34
Author: Jacques Lucke
Date:   Tue Mar 29 10:40:47 2022 +0200
Branches: master
https://developer.blender.org/rBa264dff4fa7dd0bb2e3c9abe805376b730d28c34

BLI: optimize Map/Set/VectorSet.clear methods

Previously, those methods would destruct and reconstruct
the data structure. While that was more simple in initial
implementation, it has some downsides which are not resolved:
* Already allocated memory is lost. So new memory would have
  to be allocated when the data structure is refilled.
* The clearing process itself was slower because it did unnecessary
  work.

===================================================================

M	source/blender/blenlib/BLI_map.hh
M	source/blender/blenlib/BLI_set.hh
M	source/blender/blenlib/BLI_vector_set.hh

===================================================================

diff --git a/source/blender/blenlib/BLI_map.hh b/source/blender/blenlib/BLI_map.hh
index 3cbb81b5c7d..d76aa46502d 100644
--- a/source/blender/blenlib/BLI_map.hh
+++ b/source/blender/blenlib/BLI_map.hh
@@ -962,7 +962,13 @@ class Map {
    */
   void clear()
   {
-    this->noexcept_reset();
+    for (Slot &slot : slots_) {
+      slot.~Slot();
+      new (&slot) Slot();
+    }
+
+    removed_slots_ = 0;
+    occupied_and_removed_slots_ = 0;
   }
 
   /**
diff --git a/source/blender/blenlib/BLI_set.hh b/source/blender/blenlib/BLI_set.hh
index bf177802c97..391d31c2228 100644
--- a/source/blender/blenlib/BLI_set.hh
+++ b/source/blender/blenlib/BLI_set.hh
@@ -515,8 +515,13 @@ class Set {
    */
   void clear()
   {
-    this->~Set();
-    new (this) Set();
+    for (Slot &slot : slots_) {
+      slot.~Slot();
+      new (&slot) Slot();
+    }
+
+    removed_slots_ = 0;
+    occupied_and_removed_slots_ = 0;
   }
 
   /**
diff --git a/source/blender/blenlib/BLI_vector_set.hh b/source/blender/blenlib/BLI_vector_set.hh
index 23284fd94bc..4ae1bf9000d 100644
--- a/source/blender/blenlib/BLI_vector_set.hh
+++ b/source/blender/blenlib/BLI_vector_set.hh
@@ -531,7 +531,14 @@ class VectorSet {
    */
   void clear()
   {
-    this->noexcept_reset();
+    destruct_n(keys_, this->size());
+    for (Slot &slot : slots_) {
+      slot.~Slot();
+      new (&slot) Slot();
+    }
+
+    removed_slots_ = 0;
+    occupied_and_removed_slots_ = 0;
   }
 
   /**