try to limit cell interpreting to only visible cells when drawing

If there's a document with a huge formula group, InterpretDirtyCells()
on load will only interpret the range needed for drawing. But then
scrolling just a bit could result in e.g. IsValue() call on a cell,
and that could result in unrestricted Interpret() on the whole
huge formula group, which could be slow. So explicitly interpret
just the drawn cells in the hope that it'll avoid any further
Interpret() calls.

Change-Id: I01c9f95cf8a1cf240b798feef27d21010957030c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/133306
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>
(cherry picked from commit 64cb1d10fffccebbc825c858083f13eb717b0553)

7 files changed, 66 insertions, 6 deletions

diff --git a/sc/inc/column.hxx b/sc/inc/column.hxx
index fd1b42a0f81b..5658915007a1 100644
--- a/sc/inc/column.hxx
+++ b/sc/inc/column.hxx
@@ -714,6 +714,7 @@ public:
     bool IsDrawObjectsEmptyBlock(SCROW nStartRow, SCROW nEndRow) const;
 
     void InterpretDirtyCells( SCROW nRow1, SCROW nRow2 );
+    void InterpretCellsIfNeeded( SCROW nRow1, SCROW nRow2 );
 
     static void JoinNewFormulaCell( const sc::CellStoreType::position_type& aPos, ScFormulaCell& rCell );
 
diff --git a/sc/inc/document.hxx b/sc/inc/document.hxx
index fc96571c0b5d..76798748e04f 100644
--- a/sc/inc/document.hxx
+++ b/sc/inc/document.hxx
@@ -1359,6 +1359,8 @@ public:
     void              SetDirty( const ScRange&, bool bIncludeEmptyCells );
     void              SetTableOpDirty( const ScRange& );  // for Interpreter TableOp
     void              InterpretDirtyCells( const ScRangeList& rRanges );
+    // Interprets cells that have NeedsInterpret(), i.e. the same like calling MaybeInterpret() on them.
+    void              InterpretCellsIfNeeded( const ScRangeList& rRanges );
     SC_DLLPUBLIC void CalcAll();
     SC_DLLPUBLIC void CalcAfterLoad( bool bStartListening = true );
     void              CompileAll();
diff --git a/sc/inc/table.hxx b/sc/inc/table.hxx
index 57a332d8708f..4e4e9d8d00c3 100644
--- a/sc/inc/table.hxx
+++ b/sc/inc/table.hxx
@@ -1051,6 +1051,7 @@ public:
     void FillMatrix( ScMatrix& rMat, SCCOL nCol1, SCROW nRow1, SCCOL nCol2, SCROW nRow2, svl::SharedStringPool* pPool ) const;
 
     void InterpretDirtyCells( SCCOL nCol1, SCROW nRow1, SCCOL nCol2, SCROW nRow2 );
+    void InterpretCellsIfNeeded( SCCOL nCol1, SCROW nRow1, SCCOL nCol2, SCROW nRow2 );
 
     void SetFormulaResults( SCCOL nCol, SCROW nRow, const double* pResults, size_t nLen );
 
diff --git a/sc/source/core/data/column3.cxx b/sc/source/core/data/column3.cxx
index ba494e62bb98..851abbad39ba 100644
--- a/sc/source/core/data/column3.cxx
+++ b/sc/source/core/data/column3.cxx
@@ -104,13 +104,11 @@ void ScColumn::BroadcastRows( SCROW nStartRow, SCROW nEndRow, SfxHintId nHint )
 
 namespace {
 
-class DirtyCellInterpreter
+class CellInterpreterBase
 {
-public:
-    void operator() (size_t, ScFormulaCell* p)
+protected:
+    void Interpret(ScFormulaCell* p)
     {
-        if(!p->GetDirty())
-            return;
         // Interpret() takes a range in a formula group, so group those together.
         if( firstCell != nullptr && p->GetCellGroup() == p->GetCellGroup()
             && p->aPos.Row() == lastPos.Row() + 1 )
@@ -129,7 +127,7 @@ public:
         lastPos = p->aPos;
 
     }
-    ~DirtyCellInterpreter()
+    ~CellInterpreterBase()
     {
         flushPending();
     }
@@ -146,6 +144,26 @@ private:
     ScAddress lastPos;
 };
 
+class DirtyCellInterpreter : public CellInterpreterBase
+{
+public:
+    void operator() (size_t, ScFormulaCell* p)
+    {
+        if(p->GetDirty())
+            Interpret(p);
+    }
+};
+
+class NeedsInterpretCellInterpreter : public CellInterpreterBase
+{
+public:
+    void operator() (size_t, ScFormulaCell* p)
+    {
+        if(p->NeedsInterpret())
+            Interpret(p);
+    }
+};
+
 }
 
 void ScColumn::InterpretDirtyCells( SCROW nRow1, SCROW nRow2 )
@@ -157,6 +175,15 @@ void ScColumn::InterpretDirtyCells( SCROW nRow1, SCROW nRow2 )
     sc::ProcessFormula(maCells.begin(), maCells, nRow1, nRow2, aFunc);
 }
 
+void ScColumn::InterpretCellsIfNeeded( SCROW nRow1, SCROW nRow2 )
+{
+    if (!GetDoc().ValidRow(nRow1) || !GetDoc().ValidRow(nRow2) || nRow1 > nRow2)
+        return;
+
+    NeedsInterpretCellInterpreter aFunc;
+    sc::ProcessFormula(maCells.begin(), maCells, nRow1, nRow2, aFunc);
+}
+
 void ScColumn::DeleteContent( SCROW nRow, bool bBroadcast )
 {
     sc::CellStoreType::position_type aPos = maCells.position(nRow);
diff --git a/sc/source/core/data/document.cxx b/sc/source/core/data/document.cxx
index 7cf852ecc9e4..9847e1f60bea 100644
--- a/sc/source/core/data/document.cxx
+++ b/sc/source/core/data/document.cxx
@@ -3935,6 +3935,23 @@ void ScDocument::InterpretDirtyCells( const ScRangeList& rRanges )
     mpFormulaGroupCxt.reset();
 }
 
+void ScDocument::InterpretCellsIfNeeded( const ScRangeList& rRanges )
+{
+    for (size_t nPos=0, nRangeCount = rRanges.size(); nPos < nRangeCount; nPos++)
+    {
+        const ScRange& rRange = rRanges[nPos];
+        for (SCTAB nTab = rRange.aStart.Tab(); nTab <= rRange.aEnd.Tab(); ++nTab)
+        {
+            ScTable* pTab = FetchTable(nTab);
+            if (!pTab)
+                return;
+
+            pTab->InterpretCellsIfNeeded(
+                rRange.aStart.Col(), rRange.aStart.Row(), rRange.aEnd.Col(), rRange.aEnd.Row());
+        }
+    }
+}
+
 void ScDocument::AddTableOpFormulaCell( ScFormulaCell* pCell )
 {
     if (m_TableOpList.empty())
diff --git a/sc/source/core/data/table1.cxx b/sc/source/core/data/table1.cxx
index 377dfa3d2114..71985c0475e7 100644
--- a/sc/source/core/data/table1.cxx
+++ b/sc/source/core/data/table1.cxx
@@ -2603,6 +2603,13 @@ void ScTable::InterpretDirtyCells( SCCOL nCol1, SCROW nRow1, SCCOL nCol2, SCROW
         aCol[nCol].InterpretDirtyCells(nRow1, nRow2);
 }
 
+void ScTable::InterpretCellsIfNeeded( SCCOL nCol1, SCROW nRow1, SCCOL nCol2, SCROW nRow2 )
+{
+    nCol2 = ClampToAllocatedColumns(nCol2);
+    for (SCCOL nCol = nCol1; nCol <= nCol2; ++nCol)
+        aCol[nCol].InterpretCellsIfNeeded(nRow1, nRow2);
+}
+
 void ScTable::SetFormulaResults( SCCOL nCol, SCROW nRow, const double* pResults, size_t nLen )
 {
     if (!ValidCol(nCol))
diff --git a/sc/source/ui/view/output2.cxx b/sc/source/ui/view/output2.cxx
index e10349ed6a06..ce247163c853 100644
--- a/sc/source/ui/view/output2.cxx
+++ b/sc/source/ui/view/output2.cxx
@@ -1552,6 +1552,11 @@ tools::Rectangle ScOutputData::LayoutStrings(bool bPixelToLogic, bool bPaint, co
     const SfxItemSet* pOldCondSet = nullptr;
     SvtScriptType nOldScript = SvtScriptType::NONE;
 
+    // Try to limit interpreting to only visible cells. Calling e.g. IsValue()
+    // on a formula cell that needs interpreting would call Interpret()
+    // for the entire formula group, which could be large.
+    mpDoc->InterpretCellsIfNeeded( ScRange( nX1, nY1, nTab, nX2, nY2, nTab ));
+
     // alternative pattern instances in case we need to modify the pattern
     // before processing the cell value.
     std::vector<std::unique_ptr<ScPatternAttr> > aAltPatterns;