1. Life after Calc CoreChangeKohei Yoshida 2. Topics What change
was made in Calc core. Affected areas. Expectation vs reality.
Going forward. 3. What change was made in Calc
core.https://libreoffice-from-collabora.com 4. ScDocumentOld
modelScTableScColumnScValueCellScBaseCellBroadcaster (8
bytes)ScFormulaCellText width (2 bytes)Cell type (1 byte)Script
type (1 byte)ScStringCell ScEditCellScNoteCell* 5. New
modelScDocumentScTablemdds::multi_type_vectorsvl::SharedString
blockdouble blockEditTextObject blockScFormulaCell
blockScColumnBroadcasterText widthScript typeCell value 6.
Iterating over cells (old way) 7. Iterating over cells (new way) 8.
Before shared formulaScFormulaCell ScTokenArrayScFormulaCell
ScTokenArrayScFormulaCell ScTokenArrayScFormulaCell
ScTokenArrayScFormulaCell ScTokenArrayScFormulaCell
ScTokenArrayScFormulaCell ScTokenArray 9. After shared
formulaScFormulaCellScTokenArrayScFormulaCellScFormulaCellScFormulaCellScFormulaCellScFormulaCellScFormulaCellScFormulaCellGroup
10. Shared string
conceptsvl::SharedStringPoolsvl::SharedStringOriginal string
poolUpcased string poolsvl::SharedStringsvl::SharedString 11.
String comparison (old way) 12. String comparison (new way) 13.
Bottom line... Largest refactoring effort in Calc code. Most
critical parts of Calc code havechanged. Shared formula -
ScFormulaCell nolonger owns ScTokenArray at all times. Shared
string - all string objects need tobe pooled. Random access to cell
array is no longerO(1). 14. Affected
areashttps://libreoffice-from-collabora.com 15. Calc95
%Non-scientific estimateAffected by core change 16. What features
are affected?Undo / RedoFormula Dependency Reference Updates Copy
& PasteSorting ODS Import / ExportExcel Import / Export Named
RangeContent RenderingFind & ReplaceCell CommentCell
EditingDatabase RangeLive SpellcheckVBA API LayerUNO API LayerSYLK
Import / ExportDBF Import / ExportCppUnit TestRTF Import Quattro
Pro ImportHTML Import / ExportExternal ReferenceDIF Import /
ExportChange TrackingCSV Import / ExportConditional FormattingChart
Data ProviderCell ValidationFormula CalculationFormula Tokenization
Case ConversionAutofilter ... 17. Expectation vs
Realityhttps://libreoffice-from-collabora.com 18. Check #120 to 50%
of the code changewould cause regressions.Almost all code changes
causedregressions in some form. Some didmore than others. 19. Check
#2The worst part is behind us. We justneed to fix trivial bugs.The
worst part was yet to come.Lots of medium-to-large
follow-uprefactoring ensued. 20. Check #3Just focus on regressions
duringthe 4.2 releases, and go back tonormal for the 4.3.We did fix
the worst ones in the 4.2cycle. But many still remain. 21. Check
#4We already wrote a lot of unit testsfor Calc core prior to the
change.They should keep us safe.We ended up doubling the amountof
unit tests for Calc during the 4.2period. We still dont have
enough. 22. Check #5As a responsible coder, I will fix allthe bugs
my change caused.Calcs core is too large for onecoder to handle. We
need multiplepeople who can handle bugs inCalc core. 23. Going
forwardhttps://libreoffice-from-collabora.com 24. Challenges we
face Squash remainder of regressions causedby the core change. The
number still toohigh. Gather more people becomingcomfortable
handling bug fixes in Calccore. Build the culture of writing unit
test foreach and every bug fix. 25. Unit test is key One unit test
is worth 20 future bugfixes. A bug fix does not finish until
youwrite a test. Writing unit test is courtesy for yourfellow
developers. We really dont have a choice. 26. Unit test is key
(repeated) A bug fix without a unit test WILL GETBROKEN AGAIN in
the next release. A bug fix with a unit test WILLREMAIN FIXED
FOREVER.Which one will beyour choice? 27.
THANKS!https://libreoffice-from-collabora.com
