tdf#89436 fix ScHorizontalAttrIterator performance

Change-Id: I69be1a85b74ede8f02788a6370d4ebb40bddbe11

sc/inc/dociter.hxx

@@ -487,11 +487,14 @@ private:
     SCROW                   nEndRow;
 
     SCROW*                  pNextEnd;
+    SCCOL*                  pPrevColEnd;
     SCSIZE*                 pIndices;
     const ScPatternAttr**   ppPatterns;
     SCCOL                   nCol;
     SCROW                   nRow;
     bool                    bRowEmpty;
+    bool                    bRepeatedRow;
+    SCROW                   nMinNextEnd;
 
 public:
             ScHorizontalAttrIterator( ScDocument* pDocument, SCTAB nTable,

sc/source/core/data/dociter.cxx

@@ -2235,12 +2235,14 @@ ScHorizontalAttrIterator::ScHorizontalAttrIterator( ScDocument* pDocument, SCTAB
     nRow = nStartRow;
     nCol = nStartCol;
     bRowEmpty = false;
+    bRepeatedRow = false;
 
     pIndices    = new SCSIZE[nEndCol-nStartCol+1];
     pNextEnd    = new SCROW[nEndCol-nStartCol+1];
+    pPrevColEnd = new SCCOL[nEndCol-nStartCol+1];
     ppPatterns  = new const ScPatternAttr*[nEndCol-nStartCol+1];
 
-    SCROW nSkipTo = MAXROW;
+    nMinNextEnd = MAXROW;
     bool bEmpty = true;
     for (i=nStartCol; i<=nEndCol; i++)
     {
@@ -2253,12 +2255,12 @@ ScHorizontalAttrIterator::ScHorizontalAttrIterator( ScDocument* pDocument, SCTAB
 
         const ScPatternAttr* pPattern = pArray->pData[nIndex].pPattern;
         SCROW nThisEnd = pArray->pData[nIndex].nRow;
+
+        if ( nThisEnd < nMinNextEnd )
+            nMinNextEnd = nThisEnd; // nMinNextEnd can be set here already
+
         if ( IsDefaultItem( pPattern ) )
-        {
             pPattern = NULL;
-            if ( nThisEnd < nSkipTo )
-                nSkipTo = nThisEnd; // nSkipTo can be set here already
-        }
         else
             bEmpty = false; // Found attributes
 
@@ -2268,7 +2270,7 @@ ScHorizontalAttrIterator::ScHorizontalAttrIterator( ScDocument* pDocument, SCTAB
     }
 
     if (bEmpty)
-        nRow = nSkipTo; // Skip until end of next section
+        nRow = nMinNextEnd; // Skip until end of next section
 
     bRowEmpty = bEmpty;
 }
@@ -2277,6 +2279,7 @@ ScHorizontalAttrIterator::~ScHorizontalAttrIterator()
 {
     delete[] ppPatterns;
     delete[] pNextEnd;
+    delete[] pPrevColEnd;
     delete[] pIndices;
 }
 
@@ -2297,8 +2300,15 @@ const ScPatternAttr* ScHorizontalAttrIterator::GetNext( SCCOL& rCol1, SCCOL& rCo
                 const ScPatternAttr* pPat = ppPatterns[nCol-nStartCol];
                 rRow = nRow;
                 rCol1 = nCol;
-                while ( nCol < nEndCol && ppPatterns[nCol+1-nStartCol] == pPat )
-                    ++nCol;
+                if ( bRepeatedRow )
+                    nCol = pPrevColEnd[nCol];
+                else
+                {
+                    while ( nCol < nEndCol && ( ppPatterns[nCol+1-nStartCol] == pPat) )
+                        ++nCol;
+                    // store the result to avoid the previous very expensive comparisons
+                    pPrevColEnd[rCol1] = nCol;
+                }
                 rCol2 = nCol;
                 ++nCol; // Count up for next call
                 return pPat; // Found it!
@@ -2309,7 +2319,13 @@ const ScPatternAttr* ScHorizontalAttrIterator::GetNext( SCCOL& rCol1, SCCOL& rCo
         ++nRow;
         if ( nRow > nEndRow ) // Already at the end?
             return NULL; // Found nothing
+        nCol = nStartCol; // Start at the left again
+
+        if ( bRepeatedRow && ! nMinNextEnd < nRow ) // use the data of the previous row
+           continue;
 
+        bRepeatedRow = true; // ppPatterns is not modified
+        nMinNextEnd = MAXROW;
         bool bEmpty = true;
         SCCOL i;
 
@@ -2319,6 +2335,7 @@ const ScPatternAttr* ScHorizontalAttrIterator::GetNext( SCCOL& rCol1, SCCOL& rCo
             if ( pNextEnd[nPos] < nRow )
             {
                 const ScAttrArray* pArray = pDoc->maTabs[nTab]->aCol[i].pAttrArray;
+                bRepeatedRow = false;
 
                 SCSIZE nIndex = ++pIndices[nPos];
                 if ( nIndex < pArray->nCount )
@@ -2344,19 +2361,15 @@ const ScPatternAttr* ScHorizontalAttrIterator::GetNext( SCCOL& rCol1, SCCOL& rCo
             }
             else if ( ppPatterns[nPos] )
                 bEmpty = false; // Area not at the end yet
+
+            if ( nMinNextEnd > pNextEnd[nPos] )
+                nMinNextEnd = pNextEnd[nPos];
+
         }
 
         if (bEmpty)
-        {
-            SCCOL nCount = nEndCol-nStartCol+1;
-            SCROW nSkipTo = pNextEnd[0]; // Search next end of area
-            for (i=1; i<nCount; i++)
-                if ( pNextEnd[i] < nSkipTo )
-                    nSkipTo = pNextEnd[i];
-            nRow = nSkipTo; // Skip empty rows
-        }
+            nRow = nMinNextEnd; // Skip empty rows
         bRowEmpty = bEmpty;
-        nCol = nStartCol; // Start at the left again
     }
 }