dynamic column container: more efficient loops over all cols

Create an ScColumnsRange class that returns a pair of (start,end)
iterators to go through the list of currently allocated columns.
This is a fairly thing wrapper around the underlying std::vector,
so it should be fairly efficient (two pointers, and pointer increment
for iteration).

If this style of iteration is acceptable, I'll go through the rest
of the code that does:

    for (SCCOL nCol=0; nCol<MAXCOLCOUNT; nCol++)

type stuff, and change it to use ScColumnsRange.

Change-Id: I81501c69b7f5566c6204dde0d87a6fe0deb9743c
Reviewed-on: https://gerrit.libreoffice.org/41413
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 10 insertions, 4 deletions

diff --git a/sc/source/core/data/table1.cxx b/sc/source/core/data/table1.cxx
index ad1a50ee3828..c10100d4777b 100644
--- a/sc/source/core/data/table1.cxx
+++ b/sc/source/core/data/table1.cxx
@@ -1681,14 +1681,14 @@ void ScTable::UpdateReference(
 void ScTable::UpdateTranspose( const ScRange& rSource, const ScAddress& rDest,
                                     ScDocument* pUndoDoc )
 {
-    for ( SCCOL i=0; i<=MAXCOL; i++ )
-        aCol[i].UpdateTranspose( rSource, rDest, pUndoDoc );
+    for (ScColumn* pCol : GetColumnsRange(0, MAXCOL))
+        pCol->UpdateTranspose( rSource, rDest, pUndoDoc );
 }
 
 void ScTable::UpdateGrow( const ScRange& rArea, SCCOL nGrowX, SCROW nGrowY )
 {
-    for ( SCCOL i=0; i<=MAXCOL; i++ )
-        aCol[i].UpdateGrow( rArea, nGrowX, nGrowY );
+    for (ScColumn* pCol : GetColumnsRange(0, MAXCOL))
+        pCol->UpdateGrow( rArea, nGrowX, nGrowY );
 }
 
 void ScTable::UpdateInsertTab( sc::RefUpdateInsertTabContext& rCxt )
@@ -2383,4 +2383,10 @@ const ScConditionalFormatList* ScTable::GetCondFormList() const
     return mpCondFormatList.get();
 }
 
+ScColumnsRange ScTable::GetColumnsRange(SCCOL nColBegin, SCCOL nColEnd) const
+{
+    // because the range is inclusive, some code will pass nColEnd<nColBegin to indicate an empty range
+    return ScColumnsRange(aCol.begin() + nColBegin, nColEnd < nColBegin ? (aCol.begin() + nColBegin) : (aCol.begin() + nColEnd + 1));
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */