tdf#88810 avoid unnecessary massive O(U)String allocations in XLSX export

Using OStringBuffer instead of fixed size character arrays.

Change-Id: I06b705e2159a1ef5990f9eb0ffedd20fe277c616

3 files changed, 17 insertions, 4 deletions

diff --git a/sc/source/filter/excel/xeroot.cxx b/sc/source/filter/excel/xeroot.cxx
index 819fe93553db..29f655160771 100644
--- a/sc/source/filter/excel/xeroot.cxx
+++ b/sc/source/filter/excel/xeroot.cxx
@@ -57,6 +57,7 @@ XclExpRootData::XclExpRootData( XclBiff eBiff, SfxMedium& rMedium,
 {
     SvtSaveOptions aSaveOpt;
     mbRelUrl = mrMedium.IsRemote() ? aSaveOpt.IsSaveRelINet() : aSaveOpt.IsSaveRelFSys();
+    maStringBuf = OStringBuffer(10); // for simple addresses, like ABC1000000
 }
 
 XclExpRootData::~XclExpRootData()
diff --git a/sc/source/filter/excel/xestream.cxx b/sc/source/filter/excel/xestream.cxx
index e5ff50c431c7..04dbb5f0086a 100644
--- a/sc/source/filter/excel/xestream.cxx
+++ b/sc/source/filter/excel/xestream.cxx
@@ -718,6 +718,11 @@ OString XclXmlUtils::ToOString( const OUString& s )
     return OUStringToOString( s, RTL_TEXTENCODING_UTF8  );
 }
 
+bool XclXmlUtils::TryToOString( OStringBuffer& s, const ScAddress& rAddress )
+{
+    return rAddress.TryFormat(s, SCA_VALID, NULL, ScAddress::Details( FormulaGrammar::CONV_XL_A1));
+}
+
 OString XclXmlUtils::ToOString( const ScAddress& rAddress )
 {
     OUString sAddress(rAddress.Format(SCA_VALID, NULL, ScAddress::Details( FormulaGrammar::CONV_XL_A1)));
@@ -760,6 +765,11 @@ static ScAddress lcl_ToAddress( const XclAddress& rAddress )
     return aAddress;
 }
 
+bool XclXmlUtils::TryToOString( OStringBuffer& s, const XclAddress& rAddress )
+{
+    return TryToOString( s, lcl_ToAddress( rAddress ));
+}
+
 OString XclXmlUtils::ToOString( const XclAddress& rAddress )
 {
     return ToOString( lcl_ToAddress( rAddress ) );
diff --git a/sc/source/filter/excel/xetable.cxx b/sc/source/filter/excel/xetable.cxx
index 70f3373771b4..5919c6145c01 100644
--- a/sc/source/filter/excel/xetable.cxx
+++ b/sc/source/filter/excel/xetable.cxx
@@ -631,8 +631,9 @@ static OString lcl_GetStyleId( XclExpXmlStream& rStrm, const XclExpCellBase& rCe
 void XclExpNumberCell::SaveXml( XclExpXmlStream& rStrm )
 {
     sax_fastparser::FSHelperPtr& rWorksheet = rStrm.GetCurrentStream();
+    OStringBuffer rBuf = rStrm.GetRoot().GetStringBuf();
     rWorksheet->startElement( XML_c,
-            XML_r,      XclXmlUtils::ToOString( GetXclPos() ).getStr(),
+            XML_r,      XclXmlUtils::TryToOString( rBuf, GetXclPos() ) ? rBuf.getStr() : XclXmlUtils::ToOString( GetXclPos() ).getStr(),
             XML_s,      lcl_GetStyleId( rStrm, *this ).getStr(),
             XML_t,      "n",
             // OOXTODO: XML_cm, XML_vm, XML_ph
@@ -923,11 +924,11 @@ void XclExpFormulaCell::SaveXml( XclExpXmlStream& rStrm )
 {
     const char* sType = NULL;
     OUString    sValue;
-
     XclXmlUtils::GetFormulaTypeAndValue( mrScFmlaCell, sType, sValue );
     sax_fastparser::FSHelperPtr& rWorksheet = rStrm.GetCurrentStream();
+    OStringBuffer rBuf = rStrm.GetRoot().GetStringBuf();
     rWorksheet->startElement( XML_c,
-            XML_r,      XclXmlUtils::ToOString( GetXclPos() ).getStr(),
+            XML_r,      XclXmlUtils::TryToOString( rBuf, GetXclPos() ) ? rBuf.getStr() : XclXmlUtils::ToOString( GetXclPos() ).getStr(),
             XML_s,      lcl_GetStyleId( rStrm, *this ).getStr(),
             XML_t,      sType,
             // OOXTODO: XML_cm, XML_vm, XML_ph
@@ -1308,8 +1309,9 @@ bool XclExpRkCell::TryMerge( const XclExpCellBase& rCell )
 void XclExpRkCell::WriteXmlContents( XclExpXmlStream& rStrm, const XclAddress& rAddress, sal_uInt32 nXFId, sal_uInt16 nRelCol )
 {
     sax_fastparser::FSHelperPtr& rWorksheet = rStrm.GetCurrentStream();
+    OStringBuffer rBuf = rStrm.GetRoot().GetStringBuf();
     rWorksheet->startElement( XML_c,
-            XML_r,      XclXmlUtils::ToOString( rAddress ).getStr(),
+            XML_r,      XclXmlUtils::TryToOString( rBuf, rAddress ) ? rBuf.getStr() : XclXmlUtils::ToOString( rAddress ).getStr(),
             XML_s,      lcl_GetStyleId( rStrm, nXFId ).getStr(),
             XML_t,      "n",
             // OOXTODO: XML_cm, XML_vm, XML_ph