internal: few more marginal optimisations from profiling (#8271)

* deco: reduce local temporars and function calls

profiling shows this is a high used function, reduce the amount of
function calls and local temporar copies and also check if we even need
to add extents at all in the loop.

* popup: optimize bfhelper in popups

pass nodes as const reference and reserve the size of the children node
vector help reduce the reallocations.

* procotol: make compositor bfhelper use const ref

use const ref for nodes and reserve second nodes vector size to reduce
amount of reallocation needed.

5 files changed, 29 insertions, 20 deletions

diff --git a/src/desktop/Popup.cpp b/src/desktop/Popup.cpp
index 9e254fa6..58995f00 100644
--- a/src/desktop/Popup.cpp
+++ b/src/desktop/Popup.cpp
@@ -288,12 +288,13 @@ bool CPopup::visible() {
     return false;
 }
 
-void CPopup::bfHelper(std::vector<CPopup*> nodes, std::function<void(CPopup*, void*)> fn, void* data) {
+void CPopup::bfHelper(std::vector<CPopup*> const& nodes, std::function<void(CPopup*, void*)> fn, void* data) {
     for (auto const& n : nodes) {
         fn(n, data);
     }
 
     std::vector<CPopup*> nodes2;
+    nodes2.reserve(nodes.size() * 2);
 
     for (auto const& n : nodes) {
         for (auto const& c : n->m_vChildren) {
diff --git a/src/desktop/Popup.hpp b/src/desktop/Popup.hpp
index 04996612..f34b8a2c 100644
--- a/src/desktop/Popup.hpp
+++ b/src/desktop/Popup.hpp
@@ -81,5 +81,5 @@ class CPopup {
 
     Vector2D    localToGlobal(const Vector2D& rel);
     Vector2D    t1ParentCoords();
-    static void bfHelper(std::vector<CPopup*> nodes, std::function<void(CPopup*, void*)> fn, void* data);
+    static void bfHelper(std::vector<CPopup*> const& nodes, std::function<void(CPopup*, void*)> fn, void* data);
 };
diff --git a/src/protocols/core/Compositor.cpp b/src/protocols/core/Compositor.cpp
index 9a2e00a9..d78d3d8b 100644
--- a/src/protocols/core/Compositor.cpp
+++ b/src/protocols/core/Compositor.cpp
@@ -252,9 +252,10 @@ void CWLSurfaceResource::resetRole() {
     role = makeShared<CDefaultSurfaceRole>();
 }
 
-void CWLSurfaceResource::bfHelper(std::vector<SP<CWLSurfaceResource>> nodes, std::function<void(SP<CWLSurfaceResource>, const Vector2D&, void*)> fn, void* data) {
+void CWLSurfaceResource::bfHelper(std::vector<SP<CWLSurfaceResource>> const& nodes, std::function<void(SP<CWLSurfaceResource>, const Vector2D&, void*)> fn, void* data) {
 
     std::vector<SP<CWLSurfaceResource>> nodes2;
+    nodes2.reserve(nodes.size() * 2);
 
     // first, gather all nodes below
     for (auto const& n : nodes) {
diff --git a/src/protocols/core/Compositor.hpp b/src/protocols/core/Compositor.hpp
index fbffd966..e5bdf082 100644
--- a/src/protocols/core/Compositor.hpp
+++ b/src/protocols/core/Compositor.hpp
@@ -147,7 +147,7 @@ class CWLSurfaceResource {
     void          dropPendingBuffer();
     void          dropCurrentBuffer();
     void          commitPendingState();
-    void          bfHelper(std::vector<SP<CWLSurfaceResource>> nodes, std::function<void(SP<CWLSurfaceResource>, const Vector2D&, void*)> fn, void* data);
+    void          bfHelper(std::vector<SP<CWLSurfaceResource>> const& nodes, std::function<void(SP<CWLSurfaceResource>, const Vector2D&, void*)> fn, void* data);
     void          updateCursorShm();
 
     friend class CWLPointerResource;
diff --git a/src/render/decorations/DecorationPositioner.cpp b/src/render/decorations/DecorationPositioner.cpp
index 3eb45546..995283c6 100644
--- a/src/render/decorations/DecorationPositioner.cpp
+++ b/src/render/decorations/DecorationPositioner.cpp
@@ -294,13 +294,11 @@ SBoxExtents CDecorationPositioner::getWindowDecorationReserved(PHLWINDOW pWindow
 }
 
 SBoxExtents CDecorationPositioner::getWindowDecorationExtents(PHLWINDOW pWindow, bool inputOnly) {
-    CBox accum = pWindow->getWindowMainSurfaceBox();
+    CBox const mainSurfaceBox = pWindow->getWindowMainSurfaceBox();
+    CBox       accum          = mainSurfaceBox;
 
     for (auto const& data : m_vWindowPositioningDatas) {
-        if (!data->pDecoration)
-            continue;
-
-        if (!(data->pDecoration->getDecorationFlags() & DECORATION_ALLOWS_MOUSE_INPUT) && inputOnly)
+        if (!data->pDecoration || (inputOnly && !(data->pDecoration->getDecorationFlags() & DECORATION_ALLOWS_MOUSE_INPUT)))
             continue;
 
         auto const window = data->pWindow.lock();
@@ -308,31 +306,40 @@ SBoxExtents CDecorationPositioner::getWindowDecorationExtents(PHLWINDOW pWindow,
             continue;
 
         CBox decoBox;
-
         if (data->positioningInfo.policy == DECORATION_POSITION_ABSOLUTE) {
-            decoBox = data->pWindow->getWindowMainSurfaceBox();
+            decoBox = mainSurfaceBox;
             decoBox.addExtents(data->positioningInfo.desiredExtents);
         } else {
-            decoBox              = data->lastReply.assignedGeometry;
-            const auto EDGEPOINT = getEdgeDefinedPoint(data->positioningInfo.edges, pWindow);
-            decoBox.translate(EDGEPOINT);
+            decoBox = data->lastReply.assignedGeometry;
+            decoBox.translate(getEdgeDefinedPoint(data->positioningInfo.edges, pWindow));
         }
 
+        // Check bounds only if decoBox extends beyond accum
         SBoxExtents extentsToAdd;
+        bool        needUpdate = false;
 
-        if (decoBox.x < accum.x)
+        if (decoBox.x < accum.x) {
             extentsToAdd.topLeft.x = accum.x - decoBox.x;
-        if (decoBox.y < accum.y)
+            needUpdate             = true;
+        }
+        if (decoBox.y < accum.y) {
             extentsToAdd.topLeft.y = accum.y - decoBox.y;
-        if (decoBox.x + decoBox.w > accum.x + accum.w)
+            needUpdate             = true;
+        }
+        if (decoBox.x + decoBox.w > accum.x + accum.w) {
             extentsToAdd.bottomRight.x = (decoBox.x + decoBox.w) - (accum.x + accum.w);
-        if (decoBox.y + decoBox.h > accum.y + accum.h)
+            needUpdate                 = true;
+        }
+        if (decoBox.y + decoBox.h > accum.y + accum.h) {
             extentsToAdd.bottomRight.y = (decoBox.y + decoBox.h) - (accum.y + accum.h);
+            needUpdate                 = true;
+        }
 
-        accum.addExtents(extentsToAdd);
+        if (needUpdate)
+            accum.addExtents(extentsToAdd);
     }
 
-    return accum.extentsFrom(pWindow->getWindowMainSurfaceBox());
+    return accum.extentsFrom(mainSurfaceBox);
 }
 
 CBox CDecorationPositioner::getBoxWithIncludedDecos(PHLWINDOW pWindow) {