Optimize: Prefer QVector over QList for QObserverList.

This list stores QObserverPair, i.e. a pair of a QFlags and pointer,
which by definition is larger than a pointer. Thus QList allocates
each node on the heap, whereas a QVector can use a single block
of memory.

This reduces allocations and improves iteration speed, as this reduces
the cache misses incurred with QList and pointer chasing.

Change-Id: Ib3a9fbaa099cb41785086857e856072b74211605
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/core/qchangearbiter_p.h b/src/core/qchangearbiter_p.h
index 75509ed49..6ecefebda 100644
--- a/src/core/qchangearbiter_p.h
+++ b/src/core/qchangearbiter_p.h
@@ -108,7 +108,7 @@ public:
 protected:
     typedef std::vector<QSceneChangePtr> ChangeQueue;
     typedef QPair<ChangeFlags, QObserverInterface *> QObserverPair;
-    typedef QList<QObserverPair> QObserverList;
+    typedef QVector<QObserverPair> QObserverList;
 
     void distributeQueueChanges(ChangeQueue *queue);