Difference between revisions of "Calc/Performance/Specific Bottlenecks"

Revision as of 20:15, 12 February 2009

Specific bottlenecks to be worked on, identified using tools such as valgrind --tool=callgrind.

Content relocated to Calc/Performance/Zaske, section preserved for external references linking here.

Content relocated to Calc/Performance/sorting_values_within_functions, section preserved for external references linking here.

An internal customer's document (sorry, can't publish) doing lookup queries that don't fit into the current caching strategy.

Findings:

8% in 51613353 calls to com::sun::star::i18n::casefolding::getNextChar() via
- 39696595 calls to utl::TransliterationWrapper::isEqual() via
  - ScTable::ValidQuery() via
    - 8888 calls to ScQueryCellIterator::GetThis() via
      - lcl_LookupQuery()

200873636 calls to com::sun::star::i18n::casefolding::getNextChar() via
- 33173401 calls to com::sun::star::i18n::Transliteration_caseignore::compare()

5% in com::sun::star::i18n::oneToOneMappingWithFlag::find()
- Replicated mpIndex[high] access, might be better using temporary pointer.

58% overall in ScTable::ValidQuery() and below
- TODO: Cache results of ValidQuery()? Similar to ScLookupCache?

11% overall in 27341713 calls to ScBroadcastAreaSlot::StartListeningArea() and below, of which 10% are in ::std::set::insert() and below.
- TODO: refactor implementation of broadcast slots.

@@ Line 6: / Line 6: @@
 Content relocated to [[Calc/Performance/Zaske]], section preserved for external references linking here.
-== The Ou case ==
-Loading a large plain data file takes very long.
-References:
-* [http://blogs.zdnet.com/Ou/?p=120 George Ou's blog entry]
-* [http://www.lanarchitect.net/Examples/200264-l.sxc The test case file] (.sxc)
-* [http://www.lanarchitect.net/Examples/200264-l.zip Same data, but zip'ed Excel-XML]
-Findings:
-* source/filter/xml/xmlsubti.cxx
-** 38% of time spent in ScMyTables::NewColumn() because of replicated use of aTableVec[nTableCount - 1]  (vector::operator[]) <br> Note: percentage may be off due to compilation without optimization to obtain exact line numbers that may result in STLport's vector methods being differently compiled.
-*** proposed fix: should obtain the pointer once instead.
-** Similar for other places where aTableVec[xxx] is used.
-* '''TODO:''' Check all ScMyTables::.*() and ScMyTableData::.*()
-** Especially for 63342857 calls to AddColumn() and NewColumn() that result in 1168654944 calls to operator[] ...
-** 63081776 calls to AddColumn() originate from ScXMLTableRowCellContext::EndElement()
-** Those are highly suspicious and seem to indicate that too many temporary elements are created for empty columns/cells (needs verification).
 == Sorting values within functions ==