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.

2 files changed, 3 insertions, 2 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);
 };