include/wx/stringimpl.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/stringimpl.h
   3 // Purpose:     wxStringImpl class, implementation of wxString
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     29/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 /*
  13     This header implements std::string-like string class, wxStringImpl, that is
  14     used by wxString to store the data. Alternatively, if wxUSE_STL=1,
  15     wxStringImpl is just a typedef to std:: string class.
  16 */
  17
  18 #ifndef _WX_WXSTRINGIMPL_H__
  19 #define _WX_WXSTRINGIMPL_H__
  20
  21 // ----------------------------------------------------------------------------
  22 // headers
  23 // ----------------------------------------------------------------------------
  24
  25 #include "wx/defs.h"        // everybody should include this
  26 #include "wx/wxchar.h"      // for wxChar, wxStrlen() etc.
  27
  28 #include <stdlib.h>
  29
  30 // ---------------------------------------------------------------------------
  31 // macros
  32 // ---------------------------------------------------------------------------
  33
  34 // implementation only
  35 #define   wxASSERT_VALID_INDEX(i) \
  36     wxASSERT_MSG( (size_t)(i) <= length(), _T("invalid index in wxString") )
  37
  38
  39 // ----------------------------------------------------------------------------
  40 // global data
  41 // ----------------------------------------------------------------------------
  42
  43 // global pointer to empty string
  44 extern WXDLLIMPEXP_DATA_BASE(const wxChar*) wxEmptyString;
  45
  46
  47 // ----------------------------------------------------------------------------
  48 // deal with STL/non-STL/non-STL-but-wxUSE_STD_STRING
  49 // ----------------------------------------------------------------------------
  50
  51 #define wxUSE_STL_BASED_WXSTRING  wxUSE_STL
  52
  53 // in both cases we need to define wxStdString
  54 #if wxUSE_STL_BASED_WXSTRING || wxUSE_STD_STRING
  55
  56 #include "wx/beforestd.h"
  57 #include <string>
  58 #include "wx/afterstd.h"
  59
  60 #if wxUSE_UNICODE_WCHAR
  61     #ifdef HAVE_STD_WSTRING
  62         typedef std::wstring wxStdString;
  63     #else
  64         typedef std::basic_string<wxChar> wxStdString;
  65     #endif
  66 #else
  67     typedef std::string wxStdString;
  68 #endif
  69
  70 #endif // need <string>
  71
  72 #if wxUSE_STL_BASED_WXSTRING
  73
  74     // we always want ctor from std::string when using std::string internally
  75     #undef wxUSE_STD_STRING
  76     #define wxUSE_STD_STRING 1
  77
  78     #if (defined(__GNUG__) && (__GNUG__ < 3)) || \
  79         (defined(_MSC_VER) && (_MSC_VER <= 1200))
  80         #define wxSTRING_BASE_HASNT_CLEAR
  81     #endif
  82
  83     typedef wxStdString wxStringImpl;
  84 #else // if !wxUSE_STL_BASED_WXSTRING
  85
  86 // in non-STL mode, compare() is implemented in wxString and not wxStringImpl
  87 #undef HAVE_STD_STRING_COMPARE
  88
  89 // ---------------------------------------------------------------------------
  90 // string data prepended with some housekeeping info (used by wxString class),
  91 // is never used directly (but had to be put here to allow inlining)
  92 // ---------------------------------------------------------------------------
  93
  94 struct WXDLLIMPEXP_BASE wxStringData
  95 {
  96   int     nRefs;        // reference count
  97   size_t  nDataLength,  // actual string length
  98           nAllocLength; // allocated memory size
  99
 100   // mimics declaration 'wxChar data[nAllocLength]'
 101   wxChar* data() const { return (wxChar*)(this + 1); }
 102
 103   // empty string has a special ref count so it's never deleted
 104   bool  IsEmpty()   const { return (nRefs == -1); }
 105   bool  IsShared()  const { return (nRefs > 1);   }
 106
 107   // lock/unlock
 108   void  Lock()   { if ( !IsEmpty() ) nRefs++;                    }
 109
 110   // VC++ will refuse to inline Unlock but profiling shows that it is wrong
 111 #if defined(__VISUALC__) && (__VISUALC__ >= 1200)
 112   __forceinline
 113 #endif
 114   // VC++ free must take place in same DLL as allocation when using non dll
 115   // run-time library (e.g. Multithreaded instead of Multithreaded DLL)
 116 #if defined(__VISUALC__) && defined(_MT) && !defined(_DLL)
 117   void  Unlock() { if ( !IsEmpty() && --nRefs == 0) Free();  }
 118   // we must not inline deallocation since allocation is not inlined
 119   void  Free();
 120 #else
 121   void  Unlock() { if ( !IsEmpty() && --nRefs == 0) free(this);  }
 122 #endif
 123
 124   // if we had taken control over string memory (GetWriteBuf), it's
 125   // intentionally put in invalid state
 126   void  Validate(bool b)  { nRefs = (b ? 1 : 0); }
 127   bool  IsValid() const   { return (nRefs != 0); }
 128 };
 129
 130 class WXDLLIMPEXP_BASE wxStringImpl
 131 {
 132 public:
 133   // an 'invalid' value for string index, moved to this place due to a CW bug
 134   static const size_t npos;
 135
 136 protected:
 137   // points to data preceded by wxStringData structure with ref count info
 138   wxStringCharType *m_pchData;
 139
 140   // accessor to string data
 141   wxStringData* GetStringData() const { return (wxStringData*)m_pchData - 1; }
 142
 143   // string (re)initialization functions
 144     // initializes the string to the empty value (must be called only from
 145     // ctors, use Reinit() otherwise)
 146   void Init() { m_pchData = (wxStringCharType *)wxEmptyString; }
 147     // initializes the string with (a part of) C-string
 148   void InitWith(const wxStringCharType *psz, size_t nPos = 0, size_t nLen = npos);
 149     // as Init, but also frees old data
 150   void Reinit() { GetStringData()->Unlock(); Init(); }
 151
 152   // memory allocation
 153     // allocates memory for string of length nLen
 154   bool AllocBuffer(size_t nLen);
 155     // effectively copies data to string
 156   bool AssignCopy(size_t, const wxStringCharType *);
 157
 158   // append a (sub)string
 159   bool ConcatSelf(size_t nLen, const wxStringCharType *src, size_t nMaxLen);
 160   bool ConcatSelf(size_t nLen, const wxStringCharType *src)
 161     { return ConcatSelf(nLen, src, nLen); }
 162
 163   // functions called before writing to the string: they copy it if there
 164   // are other references to our data (should be the only owner when writing)
 165   bool CopyBeforeWrite();
 166   bool AllocBeforeWrite(size_t);
 167
 168     // compatibility with wxString
 169   bool Alloc(size_t nLen);
 170
 171 public:
 172   // standard types
 173   typedef wxStringCharType value_type;
 174   typedef wxStringCharType char_type;
 175   typedef size_t size_type;
 176   typedef value_type& reference;
 177   typedef const value_type& const_reference;
 178   typedef value_type* pointer;
 179   typedef const value_type* const_pointer;
 180   typedef value_type *iterator;
 181   typedef const value_type *const_iterator;
 182
 183   // constructors and destructor
 184     // ctor for an empty string
 185   wxStringImpl() { Init(); }
 186     // copy ctor
 187   wxStringImpl(const wxStringImpl& stringSrc)
 188   {
 189     wxASSERT_MSG( stringSrc.GetStringData()->IsValid(),
 190                   _T("did you forget to call UngetWriteBuf()?") );
 191
 192     if ( stringSrc.empty() ) {
 193       // nothing to do for an empty string
 194       Init();
 195     }
 196     else {
 197       m_pchData = stringSrc.m_pchData;            // share same data
 198       GetStringData()->Lock();                    // => one more copy
 199     }
 200   }
 201     // string containing nRepeat copies of ch
 202   wxStringImpl(size_type nRepeat, wxStringCharType ch);
 203     // ctor takes first nLength characters from C string
 204     // (default value of npos means take all the string)
 205   wxStringImpl(const wxStringCharType *psz)
 206       { InitWith(psz, 0, npos); }
 207   wxStringImpl(const wxStringCharType *psz, size_t nLength)
 208       { InitWith(psz, 0, nLength); }
 209     // take nLen chars starting at nPos
 210   wxStringImpl(const wxStringImpl& str, size_t nPos, size_t nLen)
 211   {
 212     wxASSERT_MSG( str.GetStringData()->IsValid(),
 213                   _T("did you forget to call UngetWriteBuf()?") );
 214     Init();
 215     size_t strLen = str.length() - nPos; nLen = strLen < nLen ? strLen : nLen;
 216     InitWith(str.c_str(), nPos, nLen);
 217   }
 218     // take all characters from pStart to pEnd
 219   wxStringImpl(const void *pStart, const void *pEnd);
 220
 221     // dtor is not virtual, this class must not be inherited from!
 222   ~wxStringImpl()
 223   {
 224 #if defined(__VISUALC__) && (__VISUALC__ >= 1200)
 225       //RN - according to the above VC++ does indeed inline this,
 226       //even though it spits out two warnings
 227       #pragma warning (disable:4714)
 228 #endif
 229
 230       GetStringData()->Unlock();
 231   }
 232
 233 #if defined(__VISUALC__) && (__VISUALC__ >= 1200)
 234     //re-enable inlining warning
 235     #pragma warning (default:4714)
 236 #endif
 237   // overloaded assignment
 238     // from another wxString
 239   wxStringImpl& operator=(const wxStringImpl& stringSrc);
 240     // from a character
 241   wxStringImpl& operator=(wxStringCharType ch);
 242     // from a C string
 243   wxStringImpl& operator=(const wxStringCharType *psz);
 244
 245     // return the length of the string
 246   size_type length() const { return GetStringData()->nDataLength; }
 247     // return the length of the string
 248   size_type size() const { return length(); }
 249     // return the maximum size of the string
 250   size_type max_size() const { return npos; }
 251     // resize the string, filling the space with c if c != 0
 252   void resize(size_t nSize, wxStringCharType ch = '\0');
 253     // delete the contents of the string
 254   void clear() { erase(0, npos); }
 255     // returns true if the string is empty
 256   bool empty() const { return length() == 0; }
 257     // inform string about planned change in size
 258   void reserve(size_t sz) { Alloc(sz); }
 259   size_type capacity() const { return GetStringData()->nAllocLength; }
 260
 261   // lib.string.access
 262     // return the character at position n
 263   value_type at(size_type n) const
 264     { wxASSERT_VALID_INDEX( n ); return m_pchData[n]; }
 265     // returns the writable character at position n
 266   reference at(size_type n)
 267   {
 268     wxASSERT_VALID_INDEX( n );
 269     CopyBeforeWrite();
 270     return m_pchData[n];
 271   } // FIXME-UTF8: not useful for us...?
 272
 273   // lib.string.modifiers
 274     // append elements str[pos], ..., str[pos+n]
 275   wxStringImpl& append(const wxStringImpl& str, size_t pos, size_t n)
 276   {
 277     wxASSERT(pos <= str.length());
 278     ConcatSelf(n, str.c_str() + pos, str.length() - pos);
 279     return *this;
 280   }
 281     // append a string
 282   wxStringImpl& append(const wxStringImpl& str)
 283     { ConcatSelf(str.length(), str.c_str()); return *this; }
 284     // append first n (or all if n == npos) characters of sz
 285   wxStringImpl& append(const wxStringCharType *sz)
 286     { ConcatSelf(wxStrlen(sz), sz); return *this; }
 287   wxStringImpl& append(const wxStringCharType *sz, size_t n)
 288     { ConcatSelf(n, sz); return *this; }
 289     // append n copies of ch
 290   wxStringImpl& append(size_t n, wxStringCharType ch);
 291     // append from first to last
 292   wxStringImpl& append(const_iterator first, const_iterator last)
 293     { ConcatSelf(last - first, first); return *this; }
 294
 295     // same as `this_string = str'
 296   wxStringImpl& assign(const wxStringImpl& str)
 297     { return *this = str; }
 298     // same as ` = str[pos..pos + n]
 299   wxStringImpl& assign(const wxStringImpl& str, size_t pos, size_t n)
 300     { clear(); return append(str, pos, n); }
 301     // same as `= first n (or all if n == npos) characters of sz'
 302   wxStringImpl& assign(const wxStringCharType *sz)
 303     { clear(); return append(sz, wxStrlen(sz)); }
 304   wxStringImpl& assign(const wxStringCharType *sz, size_t n)
 305     { clear(); return append(sz, n); }
 306     // same as `= n copies of ch'
 307   wxStringImpl& assign(size_t n, wxStringCharType ch)
 308     { clear(); return append(n, ch); }
 309     // assign from first to last
 310   wxStringImpl& assign(const_iterator first, const_iterator last)
 311     { clear(); return append(first, last); }
 312
 313     // first valid index position
 314   const_iterator begin() const { return m_pchData; }
 315   iterator begin();
 316     // position one after the last valid one
 317   const_iterator end() const { return m_pchData + length(); }
 318   iterator end();
 319
 320     // insert another string
 321   wxStringImpl& insert(size_t nPos, const wxStringImpl& str)
 322   {
 323     wxASSERT( str.GetStringData()->IsValid() );
 324     return insert(nPos, str.c_str(), str.length());
 325   }
 326     // insert n chars of str starting at nStart (in str)
 327   wxStringImpl& insert(size_t nPos, const wxStringImpl& str, size_t nStart, size_t n)
 328   {
 329     wxASSERT( str.GetStringData()->IsValid() );
 330     wxASSERT( nStart < str.length() );
 331     size_t strLen = str.length() - nStart;
 332     n = strLen < n ? strLen : n;
 333     return insert(nPos, str.c_str() + nStart, n);
 334   }
 335     // insert first n (or all if n == npos) characters of sz
 336   wxStringImpl& insert(size_t nPos, const wxStringCharType *sz, size_t n = npos);
 337     // insert n copies of ch
 338   wxStringImpl& insert(size_t nPos, size_t n, wxStringCharType ch)// FIXME-UTF8: tricky
 339     { return insert(nPos, wxStringImpl(n, ch)); }
 340   iterator insert(iterator it, wxStringCharType ch) // FIXME-UTF8: tricky
 341     { size_t idx = it - begin(); insert(idx, 1, ch); return begin() + idx; }
 342   void insert(iterator it, const_iterator first, const_iterator last)
 343     { insert(it - begin(), first, last - first); }
 344   void insert(iterator it, size_type n, wxStringCharType ch)
 345     { insert(it - begin(), n, ch); }
 346
 347     // delete characters from nStart to nStart + nLen
 348   wxStringImpl& erase(size_type pos = 0, size_type n = npos);
 349   iterator erase(iterator first, iterator last)
 350   {
 351     size_t idx = first - begin();
 352     erase(idx, last - first);
 353     return begin() + idx;
 354   }
 355   iterator erase(iterator first);
 356
 357   // explicit conversion to C string (use this with printf()!)
 358   const wxStringCharType* c_str() const { return m_pchData; }
 359   const wxStringCharType* data() const { return m_pchData; }
 360
 361     // replaces the substring of length nLen starting at nStart
 362   wxStringImpl& replace(size_t nStart, size_t nLen, const wxStringCharType* sz);
 363     // replaces the substring of length nLen starting at nStart
 364   wxStringImpl& replace(size_t nStart, size_t nLen, const wxStringImpl& str)
 365     { return replace(nStart, nLen, str.c_str()); }
 366     // replaces the substring with nCount copies of ch
 367   wxStringImpl& replace(size_t nStart, size_t nLen, size_t nCount, wxStringCharType ch);
 368     // replaces a substring with another substring
 369   wxStringImpl& replace(size_t nStart, size_t nLen,
 370                         const wxStringImpl& str, size_t nStart2, size_t nLen2);
 371     // replaces the substring with first nCount chars of sz
 372   wxStringImpl& replace(size_t nStart, size_t nLen,
 373                         const wxStringCharType* sz, size_t nCount);
 374   wxStringImpl& replace(iterator first, iterator last, const_pointer s)
 375     { return replace(first - begin(), last - first, s); }
 376   wxStringImpl& replace(iterator first, iterator last, const_pointer s,
 377                         size_type n)
 378     { return replace(first - begin(), last - first, s, n); }
 379   wxStringImpl& replace(iterator first, iterator last, const wxStringImpl& s)
 380     { return replace(first - begin(), last - first, s); }
 381   wxStringImpl& replace(iterator first, iterator last, size_type n, wxStringCharType c)
 382     { return replace(first - begin(), last - first, n, c); }
 383   wxStringImpl& replace(iterator first, iterator last,
 384                         const_iterator first1, const_iterator last1)
 385     { return replace(first - begin(), last - first, first1, last1 - first1); }
 386
 387     // swap two strings
 388   void swap(wxStringImpl& str);
 389
 390     // All find() functions take the nStart argument which specifies the
 391     // position to start the search on, the default value is 0. All functions
 392     // return npos if there were no match.
 393
 394     // find a substring
 395   size_t find(const wxStringImpl& str, size_t nStart = 0) const;
 396
 397     // find first n characters of sz
 398   size_t find(const wxStringCharType* sz, size_t nStart = 0, size_t n = npos) const;
 399
 400     // find the first occurence of character ch after nStart
 401   size_t find(wxStringCharType ch, size_t nStart = 0) const;
 402
 403     // rfind() family is exactly like find() but works right to left
 404
 405     // as find, but from the end
 406   size_t rfind(const wxStringImpl& str, size_t nStart = npos) const;
 407
 408     // as find, but from the end
 409   size_t rfind(const wxStringCharType* sz, size_t nStart = npos,
 410                size_t n = npos) const;
 411     // as find, but from the end
 412   size_t rfind(wxStringCharType ch, size_t nStart = npos) const;
 413
 414   size_type copy(wxStringCharType* s, size_type n, size_type pos = 0);
 415
 416   // substring extraction
 417   wxStringImpl substr(size_t nStart = 0, size_t nLen = npos) const;
 418
 419       // string += string
 420   wxStringImpl& operator+=(const wxStringImpl& s) { return append(s); }
 421       // string += C string
 422   wxStringImpl& operator+=(const wxStringCharType *psz) { return append(psz); }
 423       // string += char
 424   wxStringImpl& operator+=(wxStringCharType ch) { return append(1, ch); }
 425
 426 #if !wxUSE_UNICODE_UTF8
 427   // helpers for wxStringBuffer and wxStringBufferLength
 428   wxStringCharType *DoGetWriteBuf(size_t nLen);
 429   void DoUngetWriteBuf();
 430   void DoUngetWriteBuf(size_t nLen);
 431 #endif
 432
 433   friend class WXDLLIMPEXP_BASE wxString;
 434 };
 435
 436 #endif // !wxUSE_STL_BASED_WXSTRING
 437
 438 // don't pollute the library user's name space
 439 #undef wxASSERT_VALID_INDEX
 440
 441 #endif  // _WX_WXSTRINGIMPL_H__