wxStringBase strTmp;
strTmp.reserve(length()); // micro optimisation to avoid multiple mem allocs
- if ( nStart != 0 )
- strTmp.append(c_str(), nStart);
+ //This is kind of inefficient, but its pretty good considering...
+ //we don't want to use character access operators here because on STL
+ //it will freeze the reference count of strTmp, which means a deep copy
+ //at the end when swap is called
+ //
+ //Also, we can't use append with the full character pointer and must
+ //do it manually because this string can contain null characters
+ for(size_t i1 = 0; i1 < nStart; ++i1)
+ strTmp.append(1, this->c_str()[i1]);
+
+ //its safe to do the full version here because
+ //sz must be a normal c string
strTmp.append(sz);
- strTmp.append(c_str() + nStart + nLen);
+
+ for(size_t i2 = nStart + nLen; i2 < length(); ++i2)
+ strTmp.append(1, this->c_str()[i2]);
swap(strTmp);
return *this;
}
// replace first (or all) occurences of some substring with another one
-size_t
-wxString::Replace(const wxChar *szOld, const wxChar *szNew, bool bReplaceAll)
+size_t wxString::Replace(const wxChar *szOld,
+ const wxChar *szNew, bool bReplaceAll)
{
// if we tried to replace an empty string we'd enter an infinite loop below
wxCHECK_MSG( szOld && *szOld && szNew, 0,
_T("wxString::Replace(): invalid parameter") );
- size_t uiCount = 0; // count of replacements made
-
- size_t uiOldLen = wxStrlen(szOld);
-
- wxString strTemp;
- const wxChar *pCurrent = c_str();
- const wxChar *pSubstr;
- while ( *pCurrent != wxT('\0') ) {
- pSubstr = wxStrstr(pCurrent, szOld);
- if ( pSubstr == NULL ) {
- // strTemp is unused if no replacements were made, so avoid the copy
- if ( uiCount == 0 )
- return 0;
+ size_t uiCount = 0; // count of replacements made
- strTemp += pCurrent; // copy the rest
- break; // exit the loop
- }
- else {
- // take chars before match
- size_type len = strTemp.length();
- strTemp.append(pCurrent, pSubstr - pCurrent);
- if ( strTemp.length() != (size_t)(len + pSubstr - pCurrent) ) {
- wxFAIL_MSG( _T("out of memory in wxString::Replace") );
- return 0;
- }
- strTemp += szNew;
- pCurrent = pSubstr + uiOldLen; // restart after match
+ size_t uiOldLen = wxStrlen(szOld);
+ size_t uiNewLen = wxStrlen(szNew);
- uiCount++;
+ size_t dwPos = 0;
- // stop now?
- if ( !bReplaceAll ) {
- strTemp += pCurrent; // copy the rest
- break; // exit the loop
- }
+ while ( this->c_str()[dwPos] != wxT('\0') )
+ {
+ //DO NOT USE STRSTR HERE
+ //this string can contain embedded null characters,
+ //so strstr will function incorrectly
+ dwPos = find(szOld, dwPos);
+ if ( dwPos == npos )
+ break; // exit the loop
+ else
+ {
+ //replace this occurance of the old string with the new one
+ replace(dwPos, uiOldLen, szNew, uiNewLen);
+
+ //move up pos past the old string
+ dwPos += uiOldLen;
+
+ //increase replace count
+ ++uiCount;
+
+ // stop now?
+ if ( !bReplaceAll )
+ break; // exit the loop
+ }
}
- }
-
- // only done if there were replacements, otherwise would have returned above
- swap(strTemp);
- return uiCount;
+ return uiCount;
}
bool wxString::IsAscii() const