include/wx/buffer.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        buffer.h
   3 // Purpose:     auto buffer classes: buffers which automatically free memory
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     12.04.99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows license
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // these classes are for private use only for now, they're not documented
  13
  14 #ifndef _WX_BUFFER_H
  15 #define _WX_BUFFER_H
  16
  17 #include "wx/wxchar.h"
  18
  19 #include <string.h> // strdup
  20
  21 // ----------------------------------------------------------------------------
  22 // Special classes for (wide) character strings: they use malloc/free instead
  23 // of new/delete
  24 // ----------------------------------------------------------------------------
  25
  26 class wxCharBuffer
  27 {
  28 public:
  29     wxCharBuffer(const char *str)
  30     {
  31         wxASSERT_MSG( str, wxT("NULL string in wxCharBuffer") );
  32
  33         m_str = str ? strdup(str) : (char *)NULL;
  34     }
  35     wxCharBuffer(size_t len)
  36     {
  37         m_str = (char *)malloc(len+1);
  38         m_str[len] = '\0';
  39     }
  40     // no need to check for NULL, free() does it
  41    ~wxCharBuffer() { free(m_str); }
  42
  43    wxCharBuffer(const wxCharBuffer& src)
  44    {
  45      m_str = src.m_str;
  46      // no reference count yet...
  47      ((wxCharBuffer*)&src)->m_str = (char *)NULL;
  48    }
  49    wxCharBuffer& operator=(const wxCharBuffer& src)
  50    {
  51      m_str = src.m_str;
  52      // no reference count yet...
  53      ((wxCharBuffer*)&src)->m_str = (char *)NULL;
  54      return *this;
  55    }
  56
  57    const char *data() const { return m_str; }
  58    operator const char *() const { return m_str; }
  59    char operator[](size_t n) const { return m_str[n]; }
  60
  61 private:
  62    char *m_str;
  63 };
  64
  65 #if wxUSE_WCHAR_T
  66 class wxWCharBuffer
  67 {
  68 public:
  69     wxWCharBuffer(const wchar_t *wcs)
  70     {
  71         wxASSERT_MSG( wcs, wxT("NULL string in wxWCharBuffer") );
  72
  73         if (wcs) {
  74 #if ( defined(__BORLANDC__) && (__BORLANDC__ > 0x530) ) \
  75     || ( defined(__MWERKS__) && defined(__WXMSW__) )
  76           size_t siz = (std::wcslen(wcs)+1)*sizeof(wchar_t);
  77 #else
  78           size_t siz = (::wcslen(wcs)+1)*sizeof(wchar_t);
  79 #endif
  80           m_wcs = (wchar_t *)malloc(siz);
  81           memcpy(m_wcs, wcs, siz);
  82         }
  83         else m_wcs = (wchar_t *)NULL;
  84     }
  85     wxWCharBuffer(size_t len)
  86     {
  87         m_wcs = (wchar_t *)malloc((len+1)*sizeof(wchar_t));
  88         m_wcs[len] = L'\0';
  89     }
  90
  91     // no need to check for NULL, free() does it
  92    ~wxWCharBuffer() { free(m_wcs); }
  93
  94    wxWCharBuffer(const wxWCharBuffer& src)
  95    {
  96      m_wcs = src.m_wcs;
  97      // no reference count yet...
  98      ((wxWCharBuffer*)&src)->m_wcs = (wchar_t *)NULL;
  99    }
 100    wxWCharBuffer& operator=(const wxWCharBuffer& src)
 101    {
 102      m_wcs = src.m_wcs;
 103      // no reference count yet...
 104      ((wxWCharBuffer*)&src)->m_wcs = (wchar_t *)NULL;
 105      return *this;
 106    }
 107
 108    const wchar_t *data() const { return m_wcs; }
 109    operator const wchar_t *() const { return m_wcs; }
 110    wchar_t operator[](size_t n) const { return m_wcs[n]; }
 111
 112 private:
 113    wchar_t *m_wcs;
 114 };
 115 #endif
 116
 117 #if wxUSE_UNICODE
 118     #define wxMB2WXbuf wxWCharBuffer
 119     #define wxWX2MBbuf wxCharBuffer
 120     #define wxWC2WXbuf wxChar*
 121     #define wxWX2WCbuf wxChar*
 122 #else // ANSI
 123     #define wxMB2WXbuf wxChar*
 124     #define wxWX2MBbuf wxChar*
 125     #define wxWC2WXbuf wxCharBuffer
 126     #define wxWX2WCbuf wxWCharBuffer
 127 #endif // Unicode/ANSI
 128
 129
 130
 131 // ----------------------------------------------------------------------------
 132 // A class for holding growable data buffers (not necessarily strings)
 133 // ----------------------------------------------------------------------------
 134
 135 class wxMemoryBuffer
 136 {
 137 public:
 138     enum { BLOCK_SIZE = 1024 };
 139     wxMemoryBuffer(size_t size=wxMemoryBuffer::BLOCK_SIZE)
 140     {
 141         wxASSERT(size > 0);
 142         m_data = malloc(size);
 143         wxASSERT(m_data != NULL);
 144         m_size = size;
 145         m_len  = 0;
 146     }
 147
 148     ~wxMemoryBuffer() { free(m_data); }
 149
 150     // Accessors
 151     void*  GetData() const    { return m_data; }
 152     size_t GetBufSize() const { return m_size; }
 153     size_t GetDataLen() const { return m_len; }
 154
 155     void   SetBufSize(size_t size) { ResizeIfNeeded(size); }
 156     void   SetDataLen(size_t len)
 157     {
 158         wxASSERT(len <= m_size);
 159         m_len = len;
 160     }
 161
 162     // Ensure the buffer is big enough and return a pointer to it
 163     void* GetWriteBuf(size_t sizeNeeded)
 164     {
 165         ResizeIfNeeded(sizeNeeded);
 166         return m_data;
 167     }
 168     // Update the length after the write
 169     void  UngetWriteBuf(size_t sizeUsed) { SetDataLen(sizeUsed); }
 170
 171     // Like the above, but appends to the buffer
 172     void* GetAppendBuf(size_t sizeNeeded)
 173     {
 174         ResizeIfNeeded(m_len + sizeNeeded);
 175         return (char*)m_data + m_len;
 176     }
 177     void  UngetAppendBuf(size_t sizeUsed) { SetDataLen(m_len + sizeUsed); }
 178
 179     // Other ways to append to the buffer
 180     void  AppendByte(char data) {
 181         ResizeIfNeeded(m_len + 1);
 182         *(((char*)m_data)+m_len) = data;
 183         m_len += 1;
 184     }
 185     void  AppendData(void* data, size_t len)
 186     {
 187         memcpy(GetAppendBuf(len), data, len);
 188         UngetAppendBuf(len);
 189     }
 190
 191     operator const char *() const { return (const char*)m_data; }
 192
 193
 194     // Copy and assignment
 195     wxMemoryBuffer(const wxMemoryBuffer& src)
 196     {
 197         m_data = src.m_data;
 198         m_size = src.m_size;
 199         m_len  = src.m_len;
 200
 201         // no reference count yet...
 202         ((wxMemoryBuffer*)&src)->m_data = NULL;
 203         ((wxMemoryBuffer*)&src)->m_size = 0;
 204         ((wxMemoryBuffer*)&src)->m_len  = 0;
 205     }
 206
 207     wxMemoryBuffer& operator=(const wxMemoryBuffer& src)
 208     {
 209         m_data = src.m_data;
 210         m_size = src.m_size;
 211         m_len  = src.m_len;
 212
 213         // no reference count yet...
 214         ((wxMemoryBuffer*)&src)->m_data = NULL;
 215         ((wxMemoryBuffer*)&src)->m_size = 0;
 216         ((wxMemoryBuffer*)&src)->m_len  = 0;
 217
 218         return *this;
 219    }
 220
 221
 222 protected:
 223
 224     void ResizeIfNeeded(size_t newSize)
 225     {
 226         if (newSize > m_size)
 227         {
 228             m_data = realloc(m_data, newSize + wxMemoryBuffer::BLOCK_SIZE);
 229             wxASSERT(m_data != NULL);
 230             m_size = newSize + wxMemoryBuffer::BLOCK_SIZE;
 231         }
 232     }
 233
 234 private:
 235     void*       m_data;
 236     size_t      m_size;
 237     size_t      m_len;
 238 };
 239
 240
 241
 242 // ----------------------------------------------------------------------------
 243 // template class for any kind of data
 244 // ----------------------------------------------------------------------------
 245
 246 // TODO
 247
 248 #endif // _WX_BUFFER_H