ofz#24932-1 speed up GetItemState when iterating

by having SfxWhichIter track the current position in
the m_ppItems table, which means GetItemState does
not need to traverse the ranges table to find the
item position.

shaves 75% off the time of
./instdir/program/soffice.bin --calc --convert-to pdf
~/Downloads/ofz24932-1.rtf

Change-Id: Ib5fe61c75ca05bc2f1932e84b57ccfa55f8b7f74
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/135023
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 23 insertions, 7 deletions

diff --git a/include/svl/itemset.hxx b/include/svl/itemset.hxx
index 7b535fb93d6f..746ba8448afb 100644
--- a/include/svl/itemset.hxx
+++ b/include/svl/itemset.hxx
@@ -23,6 +23,7 @@
 #include <cassert>
 #include <cstddef>
 #include <memory>
+#include <optional>
 #include <utility>
 
 #include <svl/svldllapi.h>
@@ -35,6 +36,7 @@ class SfxItemPool;
 class SAL_WARN_UNUSED SVL_DLLPUBLIC SfxItemSet
 {
     friend class SfxItemIter;
+    friend class SfxWhichIter;
 
     SfxItemPool*      m_pPool;         ///< pool that stores the items
     const SfxItemSet* m_pParent;       ///< derivation
@@ -223,6 +225,12 @@ public:
     bool                        Equals(const SfxItemSet &, bool bComparePool) const;
 
     void dumpAsXml(xmlTextWriterPtr pWriter) const;
+
+private:
+    SfxItemState  GetItemStateImpl( sal_uInt16 nWhich,
+                                bool bSrchInParent,
+                                const SfxPoolItem **ppItem,
+                                std::optional<sal_uInt16> oItemsOffsetHint) const;
 };
 
 inline void SfxItemSet::SetParent( const SfxItemSet* pNew )
diff --git a/include/svl/whiter.hxx b/include/svl/whiter.hxx
index c4a49a06b622..df8c6fea79f2 100644
--- a/include/svl/whiter.hxx
+++ b/include/svl/whiter.hxx
@@ -16,19 +16,27 @@
  *   except in compliance with the License. You may obtain a copy of
  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  */
-#ifndef INCLUDED_SVL_WHITER_HXX
-#define INCLUDED_SVL_WHITER_HXX
+#pragma once
 
 #include <svl/svldllapi.h>
 #include <svl/whichranges.hxx>
 
 class SfxItemSet;
+class SfxPoolItem;
+enum class SfxItemState;
 
+/**
+ * Iterates over the which ids and the pool items arrays together (which are stored in parallel arrays).
+ * Primarily so that we can call GetItemSet on the SfxItemSet and pass in a hint, which avoids
+ * searching the array the SfxItemSet, which speeds up GetItemState greatly.
+ */
 class SVL_DLLPUBLIC SfxWhichIter
 {
-    const WhichRangesContainer& pStart;
-    const WhichPair* pRanges;
-    sal_uInt16 nOffset;
+    const SfxItemSet& m_rItemSet;
+    const WhichPair* m_pCurrentWhichPair;
+    sal_uInt16 m_nOffsetFromStartOfCurrentWhichPair;
+    /// Offset into m_ppItems array in SfxItemSet
+    sal_uInt16 m_nItemsOffset;
 
 public:
     SfxWhichIter(const SfxItemSet& rSet);
@@ -36,8 +44,8 @@ public:
     sal_uInt16 GetCurWhich() const;
     sal_uInt16 NextWhich();
     sal_uInt16 FirstWhich();
+    SfxItemState GetItemState(bool bSrchInParent = true,
+                              const SfxPoolItem** ppItem = nullptr) const;
 };
 
-#endif
-
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */