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.

1 files changed, 2 insertions, 1 deletions

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) {