[Libreoffice-commits] core.git: Branch 'distro/collabora/cp-6.4' - sc/source

[Michael Meeks (via logerrit)]

 sc/source/core/data/table2.cxx |   23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

New commits:
commit d12db838aa9da414af999707f531e5d34784772c
Author:     Michael Meeks <michael.meeks at collabora.com>
AuthorDate: Fri Jan 22 21:17:25 2021 +0000
Commit:     Michael Meeks <michael.meeks at collabora.com>
CommitDate: Sun Jan 24 01:05:52 2021 +0100

    sc: GetRowForHeight performance improvement.
    
    Instead of just skipping hidden rows, either skip or interpolate
    into visible ones.
    
    This method, and it's single caller look rather unusual to me. It is
    unclear why we would want to return the results we do, and why the
    one caller subtracts a row.
    
    Some surprising proportion of tile rendering was exercising this code
    path extremely slowly.
    
    --5.94%--ScDocument::GetPrintArea
              |
              |--5.04%--ScDrawLayer::GetPrintArea
              |          ScTable::GetRowForHeight
              |          |
              |           --4.58%--ScFlatBoolRowSegments::getRangeData
              |                     |
              |                      --2.46%--ScFlatSegmentsImpl<bool, bool>::getRangeData
    
    Change-Id: I75418d6af59a33b99e8bb0c374139e1a4ee6ef87
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109837
    Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice at gmail.com>
    Tested-by: Michael Meeks <michael.meeks at collabora.com>
    Reviewed-by: Ashod Nakashian <ash at collabora.com>
    Reviewed-by: Michael Meeks <michael.meeks at collabora.com>

diff --git a/sc/source/core/data/table2.cxx b/sc/source/core/data/table2.cxx
index 5a12b0bba520..971c8ad7cd31 100644
--- a/sc/source/core/data/table2.cxx
+++ b/sc/source/core/data/table2.cxx
@@ -3971,16 +3971,25 @@ SCROW ScTable::GetRowForHeight(sal_uLong nHeight) const
                 break;
         }
 
-        nSum += aRowHeightRange.mnValue;
+        // find the last common row between hidden & height spans
+        SCROW nLastCommon = std::min(aData.mnRow2, aRowHeightRange.mnRow2);
+        assert (nLastCommon >= nRow);
+        SCROW nCommon = nLastCommon - nRow + 1;
 
-        if (nSum > nHeight)
+        // how much further to go ?
+        sal_uLong nPixelsLeft = nHeight - nSum;
+        sal_uLong nCommonPixels = aRowHeightRange.mnValue * nCommon;
+
+        // are we in the zone ?
+        if (nCommonPixels > nPixelsLeft)
         {
+            nRow += (nPixelsLeft + aRowHeightRange.mnValue - 1) / aRowHeightRange.mnValue;
+
+            // FIXME: finding this next row is far from elegant,
+            // we have a single caller, which subtracts one as well(!?)
             if (nRow >= pDocument->MaxRow())
                 return pDocument->MaxRow();
 
-            // Find the next visible row.
-            ++nRow;
-
             if (!mpHiddenRows->getRangeData(nRow, aData))
                 // Failed to fetch the range data for whatever reason.
                 break;
@@ -3991,6 +4000,10 @@ SCROW ScTable::GetRowForHeight(sal_uLong nHeight) const
 
             return nRow <= pDocument->MaxRow() ? nRow : pDocument->MaxRow();
         }
+
+        // skip the range and keep hunting
+        nSum += nCommonPixels;
+        nRow = nLastCommon;
     }
     return -1;
 }