IMPLEMENT_DYNAMIC_CLASS(wxString, wxObject)
#endif //WXSTRING_IS_WXOBJECT
+// allocating extra space for each string consumes more memory but speeds up
+// the concatenation operations (nLen is the current string's length)
+#define EXTRA_ALLOC 16
+
// ---------------------------------------------------------------------------
// static class variables definition
// ---------------------------------------------------------------------------
const size_t wxString::npos = STRING_MAXLEN;
#endif
-// ===========================================================================
-// static class data, special inlines
-// ===========================================================================
+// ----------------------------------------------------------------------------
+// static data
+// ----------------------------------------------------------------------------
// for an empty string, GetStringData() will return this address
static int g_strEmpty[] = { -1, // ref count (locked)
// empty C style string: points to 'string data' byte of g_strEmpty
extern const char *g_szNul = (const char *)(&g_strEmpty[3]);
-// ===========================================================================
+// ----------------------------------------------------------------------------
// global functions
-// ===========================================================================
+// ----------------------------------------------------------------------------
#ifdef STD_STRING_COMPATIBILITY
#endif //std::string compatibility
+// ----------------------------------------------------------------------------
+// private classes
+// ----------------------------------------------------------------------------
+
+// this small class is used to gather statistics for performance tuning
+//#define WXSTRING_STATISTICS
+#ifdef WXSTRING_STATISTICS
+ class Averager
+ {
+ public:
+ Averager(const char *sz) { m_sz = sz; m_nTotal = m_nCount = 0; }
+ ~Averager()
+ { printf("wxString: average %s = %f\n", m_sz, ((float)m_nTotal)/m_nCount); }
+
+ void Add(uint n) { m_nTotal += n; m_nCount++; }
+
+ private:
+ uint m_nCount, m_nTotal;
+ const char *m_sz;
+ } g_averageLength("allocation size"),
+ g_averageSummandLength("summand length"),
+ g_averageConcatHit("hit probability in concat"),
+ g_averageInitialLength("initial string length");
+
+ #define STATISTICS_ADD(av, val) g_average##av.Add(val)
+#else
+ #define STATISTICS_ADD(av, val)
+#endif // WXSTRING_STATISTICS
+
// ===========================================================================
// wxString class core
// ===========================================================================
// construction
// ---------------------------------------------------------------------------
-// construct an empty string
-wxString::wxString()
-{
- Init();
-}
-
-// copy constructor
-wxString::wxString(const wxString& stringSrc)
-{
- wxASSERT( stringSrc.GetStringData()->IsValid() );
-
- if ( stringSrc.IsEmpty() ) {
- // nothing to do for an empty string
- Init();
- }
- else {
- m_pchData = stringSrc.m_pchData; // share same data
- GetStringData()->Lock(); // => one more copy
- }
-}
-
// constructs string of <nLength> copies of character <ch>
wxString::wxString(char ch, size_t nLength)
{
if ( nLength == STRING_MAXLEN )
nLength = Strlen(psz + nPos);
+ STATISTICS_ADD(InitialLength, nLength);
+
if ( nLength > 0 ) {
// trailing '\0' is written in AllocBuffer()
AllocBuffer(nLength);
}
}
-// take first nLength characters of C string psz
-// (default value of STRING_MAXLEN means take all the string)
-wxString::wxString(const char *psz, size_t nLength)
-{
- InitWith(psz, 0, nLength);
-}
-
// the same as previous constructor, but for compilers using unsigned char
wxString::wxString(const unsigned char* psz, size_t nLength)
{
#ifdef STD_STRING_COMPATIBILITY
-// ctor from a substring
-wxString::wxString(const wxString& str, size_t nPos, size_t nLen)
-{
- wxASSERT( str.GetStringData()->IsValid() );
-
- InitWith(str.c_str(), nPos, nLen == npos ? 0 : nLen);
-}
-
// poor man's iterators are "void *" pointers
wxString::wxString(const void *pStart, const void *pEnd)
{
wxASSERT( nLen > 0 ); //
wxASSERT( nLen <= INT_MAX-1 ); // max size (enough room for 1 extra)
+ STATISTICS_ADD(Length, nLen);
+
// allocate memory:
// 1) one extra character for '\0' termination
// 2) sizeof(wxStringData) for housekeeping info
- wxStringData* pData = (wxStringData*)malloc(sizeof(wxStringData) +
- (nLen + 1)*sizeof(char));
+ wxStringData* pData = (wxStringData*)
+ malloc(sizeof(wxStringData) + (nLen + EXTRA_ALLOC + 1)*sizeof(char));
pData->nRefs = 1;
- pData->data()[nLen] = '\0';
pData->nDataLength = nLen;
- pData->nAllocLength = nLen;
+ pData->nAllocLength = nLen + EXTRA_ALLOC;
m_pchData = pData->data(); // data starts after wxStringData
+ m_pchData[nLen] = '\0';
}
// must be called before changing this string
if ( pData->IsShared() ) {
pData->Unlock(); // memory not freed because shared
- AllocBuffer(pData->nDataLength);
- memcpy(m_pchData, pData->data(), (pData->nDataLength + 1)*sizeof(char));
+ uint nLen = pData->nDataLength;
+ AllocBuffer(nLen);
+ memcpy(m_pchData, pData->data(), nLen*sizeof(char));
}
- wxASSERT( !pData->IsShared() ); // we must be the only owner
+ wxASSERT( !GetStringData()->IsShared() ); // we must be the only owner
}
// must be called before replacing contents of this string
wxASSERT( nLen != 0 ); // doesn't make any sense
// must not share string and must have enough space
- register wxStringData* pData = GetStringData();
+ wxStringData* pData = GetStringData();
if ( pData->IsShared() || (nLen > pData->nAllocLength) ) {
// can't work with old buffer, get new one
pData->Unlock();
{
wxStringData *pData = GetStringData();
if ( pData->nAllocLength <= nLen ) {
- if ( pData->IsEmpty() )
+ if ( pData->IsEmpty() ) {
+ nLen += EXTRA_ALLOC;
+
+ wxStringData* pData = (wxStringData*)
+ malloc(sizeof(wxStringData) + (nLen + 1)*sizeof(char));
+ pData->nRefs = 1;
+ pData->nDataLength = 0;
+ pData->nAllocLength = nLen;
+ m_pchData = pData->data(); // data starts after wxStringData
+ m_pchData[0u] = '\0';
+ }
+ else if ( pData->IsShared() ) {
+ pData->Unlock(); // memory not freed because shared
+ uint nOldLen = pData->nDataLength;
AllocBuffer(nLen);
+ memcpy(m_pchData, pData->data(), nOldLen*sizeof(char));
+ }
else {
+ nLen += EXTRA_ALLOC;
+
wxStringData *p = (wxStringData *)
realloc(pData, sizeof(wxStringData) + (nLen + 1)*sizeof(char));
- if ( p != NULL && p != pData ) {
- // the call succeeded but the pointer changed
- pData->Unlock();
- free(pData);
-
- p->nRefs = 1;
- p->nAllocLength = nLen;
- m_pchData = p->data();
+
+ if ( p == NULL ) {
+ // @@@ what to do on memory error?
+ return;
}
- //else: do nothing: either the call failed or the pointer is unchanged
+
+ // it's not important if the pointer changed or not (the check for this
+ // is not faster than assigning to m_pchData in all cases)
+ p->nAllocLength = nLen;
+ m_pchData = p->data();
}
}
//else: we've already got enough
void wxString::Shrink()
{
wxStringData *pData = GetStringData();
- void *p = realloc(pData, sizeof(wxStringData) +
- (pData->nDataLength + 1)*sizeof(char));
- if ( p == NULL ) // huh? can't unallocate memory? unlikely but possible.
- return;
+
+ // this variable is unused in release build, so avoid the compiler warning by
+ // just not declaring it
+#ifdef __WXDEBUG__
+ void *p =
+#endif
+ realloc(pData, sizeof(wxStringData) + (pData->nDataLength + 1)*sizeof(char));
+
+ wxASSERT( p != NULL ); // can't free memory?
wxASSERT( p == pData ); // we're decrementing the size - block shouldn't move!
}
GetStringData()->Validate(TRUE);
}
-// dtor frees memory if no other strings use it
-wxString::~wxString()
-{
- GetStringData()->Unlock();
-}
-
// ---------------------------------------------------------------------------
// data access
// ---------------------------------------------------------------------------
// string concatenation
// ---------------------------------------------------------------------------
-// concatenate two sources
-// NB: assume that 'this' is a new wxString object
-void wxString::ConcatCopy(int nSrc1Len, const char *pszSrc1Data,
- int nSrc2Len, const char *pszSrc2Data)
-{
- int nNewLen = nSrc1Len + nSrc2Len;
- if ( nNewLen != 0 )
- {
- AllocBuffer(nNewLen);
- memcpy(m_pchData, pszSrc1Data, nSrc1Len*sizeof(char));
- memcpy(m_pchData + nSrc1Len, pszSrc2Data, nSrc2Len*sizeof(char));
- }
-}
-
// add something to this string
void wxString::ConcatSelf(int nSrcLen, const char *pszSrcData)
{
- // concatenating an empty string is a NOP
- if ( nSrcLen != 0 ) {
- register wxStringData *pData = GetStringData();
-
- // alloc new buffer if current is too small
- if ( pData->IsShared() ||
- pData->nDataLength + nSrcLen > pData->nAllocLength ) {
- // we have to grow the buffer, use the ConcatCopy routine
- // (which will allocate memory)
- wxStringData* pOldData = GetStringData();
- ConcatCopy(pOldData->nDataLength, m_pchData, nSrcLen, pszSrcData);
- pOldData->Unlock();
- }
- else {
- // fast concatenation when buffer big enough
- memcpy(m_pchData + pData->nDataLength, pszSrcData, nSrcLen*sizeof(char));
- pData->nDataLength += nSrcLen;
+ STATISTICS_ADD(SummandLength, nSrcLen);
- // should be enough space
- wxASSERT( pData->nDataLength <= pData->nAllocLength );
+ // concatenating an empty string is a NOP, but it happens quite rarely,
+ // so we don't waste our time checking for it
+ // if ( nSrcLen > 0 )
+ wxStringData *pData = GetStringData();
+ uint nLen = pData->nDataLength;
+ uint nNewLen = nLen + nSrcLen;
- m_pchData[pData->nDataLength] = '\0'; // put terminating '\0'
- }
+ // alloc new buffer if current is too small
+ if ( pData->IsShared() ) {
+ STATISTICS_ADD(ConcatHit, 0);
+
+ // we have to allocate another buffer
+ wxStringData* pOldData = GetStringData();
+ AllocBuffer(nNewLen);
+ memcpy(m_pchData, pOldData->data(), nLen*sizeof(char));
+ pOldData->Unlock();
}
+ else if ( nNewLen > pData->nAllocLength ) {
+ STATISTICS_ADD(ConcatHit, 0);
+
+ // we have to grow the buffer
+ Alloc(nNewLen);
+ }
+ else {
+ STATISTICS_ADD(ConcatHit, 1);
+
+ // the buffer is already big enough
+ }
+
+ // should be enough space
+ wxASSERT( nNewLen <= GetStringData()->nAllocLength );
+
+ // fast concatenation - all is done in our buffer
+ memcpy(m_pchData + nLen, pszSrcData, nSrcLen*sizeof(char));
+
+ m_pchData[nNewLen] = '\0'; // put terminating '\0'
+ GetStringData()->nDataLength = nNewLen; // and fix the length
}
/*
wxASSERT( string1.GetStringData()->IsValid() );
wxASSERT( string2.GetStringData()->IsValid() );
- wxString s;
- s.ConcatCopy(string1.GetStringData()->nDataLength, string1.m_pchData,
- string2.GetStringData()->nDataLength, string2.m_pchData);
+ wxString s = string1;
+ s += string2;
+
return s;
}
-wxString operator+(const wxString& string1, char ch)
+wxString operator+(const wxString& string, char ch)
{
- wxASSERT( string1.GetStringData()->IsValid() );
+ wxASSERT( string.GetStringData()->IsValid() );
+
+ wxString s = string;
+ s += ch;
- wxString s;
- s.ConcatCopy(string1.GetStringData()->nDataLength, string1.m_pchData, 1, &ch);
return s;
}
{
wxASSERT( string.GetStringData()->IsValid() );
- wxString s;
- s.ConcatCopy(1, &ch, string.GetStringData()->nDataLength, string.m_pchData);
+ wxString s = ch;
+ s += string;
+
return s;
}
wxASSERT( string.GetStringData()->IsValid() );
wxString s;
- s.ConcatCopy(string.GetStringData()->nDataLength, string.m_pchData,
- Strlen(psz), psz);
+ s.Alloc(Strlen(psz) + string.Len());
+ s = string;
+ s += psz;
+
return s;
}
wxASSERT( string.GetStringData()->IsValid() );
wxString s;
- s.ConcatCopy(Strlen(psz), psz,
- string.GetStringData()->nDataLength, string.m_pchData);
+ s.Alloc(Strlen(psz) + string.Len());
+ s = psz;
+ s += string;
+
return s;
}
// helper function: clone the data attached to this string
void wxString::AllocCopy(wxString& dest, int nCopyLen, int nCopyIndex) const
{
- if ( nCopyLen == 0 )
- {
+ if ( nCopyLen == 0 ) {
dest.Init();
}
- else
- {
+ else {
dest.AllocBuffer(nCopyLen);
memcpy(dest.m_pchData, m_pchData + nCopyIndex, nCopyLen*sizeof(char));
}
return iLen;
}
-#if 0
-int wxString::Scanf(const char *pszFormat, ...) const
-{
- va_list argptr;
- va_start(argptr, pszFormat);
-
- int iLen = ScanfV(pszFormat, argptr);
-
- va_end(argptr);
-
- return iLen;
-}
-
-int wxString::ScanfV(const char *pszFormat, va_list argptr) const
-{
-#ifdef __WXMSW__
- wxMessageBox("ScanfV not implemented");
- return 0;
-#else
- return vsscanf(c_str(), pszFormat, argptr);
-#endif
-}
-#endif
-
// ----------------------------------------------------------------------------
// misc other operations
// ----------------------------------------------------------------------------
// copy ctor
wxArrayString::wxArrayString(const wxArrayString& src)
{
- m_nSize = src.m_nSize;
- m_nCount = src.m_nCount;
-
- if ( m_nSize != 0 )
- m_pItems = new char *[m_nSize];
- else
- m_pItems = NULL;
+ m_nSize =
+ m_nCount = 0;
+ m_pItems = NULL;
- if ( m_nCount != 0 )
- memcpy(m_pItems, src.m_pItems, m_nCount*sizeof(char *));
+ *this = src;
}
-// copy operator
+// assignment operator
wxArrayString& wxArrayString::operator=(const wxArrayString& src)
{
- DELETEA(m_pItems);
+ Clear();
- m_nSize = src.m_nSize;
- m_nCount = src.m_nCount;
+ m_nSize = 0;
+ if ( src.m_nCount > ARRAY_DEFAULT_INITIAL_SIZE )
+ Alloc(src.m_nCount);
- if ( m_nSize != 0 )
- m_pItems = new char *[m_nCount];
- else
- m_pItems = NULL;
+ // we can't just copy the pointers here because otherwise we would share
+ // the strings with another array
+ for ( uint n = 0; n < src.m_nCount; n++ )
+ Add(src[n]);
if ( m_nCount != 0 )
memcpy(m_pItems, src.m_pItems, m_nCount*sizeof(char *));
m_pItems = new char *[m_nSize];
}
else {
+ // otherwise when it's called for the first time, nIncrement would be 0
+ // and the array would never be expanded
+ wxASSERT( ARRAY_DEFAULT_INITIAL_SIZE != 0 );
+
// add 50% but not too much
- size_t nIncrement = m_nSize >> 1;
+ size_t nIncrement = m_nSize < ARRAY_DEFAULT_INITIAL_SIZE
+ ? ARRAY_DEFAULT_INITIAL_SIZE : m_nSize >> 1;
if ( nIncrement > ARRAY_MAXSIZE_INCREMENT )
nIncrement = ARRAY_MAXSIZE_INCREMENT;
m_nSize += nIncrement;
}
// searches the array for an item (forward or backwards)
-
-// Robert Roebling (changed to bool from bool)
-
int wxArrayString::Index(const char *sz, bool bCase, bool bFromEnd) const
{
if ( bFromEnd ) {
// sort array elements using passed comparaison function
-void wxArrayString::Sort(bool bCase, bool bReverse)
+void wxArrayString::Sort(bool WXUNUSED(bCase), bool WXUNUSED(bReverse) )
{
//@@@@ TO DO
//qsort(m_pItems, m_nCount, sizeof(char *), fCmp);