WhichRangesContainer, reduce malloc in SfxItemSet

SfxItemSet shows up in perf profiles frequently,
and the hottest part is the malloc of the two arrays we need.
But most of the time, one of those arrays is a compile-time
constant.

So this change introduces
(*) WhichRangesContainer, which manages whether the SfxItemSet
owns the array it points at or not.
(*) a static const member in svl::Items (idea from mkaganski)
to store the data.

Change-Id: Icb8cdbc4d54fd76739565c575e16a744515e5355
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/118703
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/cui/source/inc/page.hxx b/cui/source/inc/page.hxx
index f38283c1c61d..02af8079a88c 100644
--- a/cui/source/inc/page.hxx
+++ b/cui/source/inc/page.hxx
@@ -64,7 +64,7 @@ typedef sal_uInt16 MarginPosition;
 
 class SvxPageDescPage : public SfxTabPage
 {
-    static const sal_uInt16 pRanges[];
+    static const WhichRangesContainer pRanges;
 private:
     OUString            sStandardRegister;
     tools::Long                nFirstLeftMargin;
@@ -174,7 +174,7 @@ public:
     virtual ~SvxPageDescPage() override;
 
     // returns the range of the Which values
-    static const sal_uInt16* GetRanges() { return pRanges; }
+    static WhichRangesContainer GetRanges() { return pRanges; }
 
     virtual bool        FillItemSet( SfxItemSet* rOutSet ) override;
     virtual void        Reset( const SfxItemSet* rSet ) override;