git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@36037 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
		
			
				
	
	
		
			273 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			273 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| ///////////////////////////////////////////////////////////////////////////////
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| // Name:        wx/buffer.h
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| // Purpose:     auto buffer classes: buffers which automatically free memory
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| // Author:      Vadim Zeitlin
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| // Modified by:
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| // Created:     12.04.99
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| // RCS-ID:      $Id$
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| // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
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| // Licence:     wxWindows licence
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| ///////////////////////////////////////////////////////////////////////////////
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| 
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| #ifndef _WX_BUFFER_H
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| #define _WX_BUFFER_H
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| 
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| #include "wx/wxchar.h"
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| 
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| #include <stdlib.h>             // malloc() and free()
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| 
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| // ----------------------------------------------------------------------------
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| // Special classes for (wide) character strings: they use malloc/free instead
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| // of new/delete
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| // ----------------------------------------------------------------------------
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| 
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| #define DEFINE_BUFFER(classname, chartype, strdupfunc)                      \
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| class WXDLLIMPEXP_BASE classname                                            \
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| {                                                                           \
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| public:                                                                     \
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|     classname(const chartype *str)                                          \
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|         : m_str(str ? strdupfunc(str) : NULL)                               \
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|     {                                                                       \
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|     }                                                                       \
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|                                                                             \
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|     classname(size_t len=0)                                                 \
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|         : m_str((chartype *)malloc((len + 1)*sizeof(chartype)))             \
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|     {                                                                       \
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|         m_str[len] = (chartype)0;                                           \
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|     }                                                                       \
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|                                                                             \
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|     /* no need to check for NULL, free() does it */                         \
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|     ~classname() { free(m_str); }                                           \
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|                                                                             \
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|     /*                                                                      \
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|         WARNING:                                                            \
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|                                                                             \
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|         the copy ctor and assignment operators change the passed in object  \
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|         even although it is declared as "const", so:                        \
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|                                                                             \
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|         a) it shouldn't be really const                                     \
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|         b) you shouldn't use it afterwards (or know that it was reset)      \
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|                                                                             \
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|         This is very ugly but is unfortunately needed to make the normal use\
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|         of classname buffer objects possible and is very similar to what    \
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|         std::auto_ptr<> does (as if it were an excuse...)                   \
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|     */                                                                      \
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|                                                                             \
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|     /*                                                                      \
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|        because of the remark above, release() is declared const even if it  \
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|        isn't really const                                                   \
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|      */                                                                     \
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|     chartype *release() const                                               \
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|     {                                                                       \
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|         chartype *p = m_str;                                                \
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|         ((classname *)this)->m_str = NULL;                                  \
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|         return p;                                                           \
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|     }                                                                       \
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|                                                                             \
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|     classname(const classname& src)                                         \
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|         : m_str(src.release())                                              \
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|     {                                                                       \
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|     }                                                                       \
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|                                                                             \
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|     classname& operator=(const chartype *str)                               \
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|     {                                                                       \
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|         free(m_str);                                                        \
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|         m_str = str ? strdupfunc(str) : NULL;                               \
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|         return *this;                                                       \
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|     }                                                                       \
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|                                                                             \
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|     classname& operator=(const classname& src)                              \
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|     {                                                                       \
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|         free(m_str);                                                        \
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|         m_str = src.release();                                              \
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|                                                                             \
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|         return *this;                                                       \
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|     }                                                                       \
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|                                                                             \
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|     chartype *data() { return m_str; }                                      \
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|     const chartype *data() const { return m_str; }                          \
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|     operator const chartype *() const { return m_str; }                     \
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|     chartype operator[](size_t n) const { return m_str[n]; }                \
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|                                                                             \
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| private:                                                                    \
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|     chartype *m_str;                                                        \
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| }
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| 
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| DEFINE_BUFFER(wxCharBuffer, char, wxStrdupA);
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| 
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| #if wxUSE_WCHAR_T
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| 
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| DEFINE_BUFFER(wxWCharBuffer, wchar_t, wxStrdupW);
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| 
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| #endif // wxUSE_WCHAR_T
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| 
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| #undef DEFINE_BUFFER
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| 
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| #if wxUSE_UNICODE
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|     #define wxMB2WXbuf wxWCharBuffer
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|     #define wxWX2MBbuf wxCharBuffer
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|     #define wxWC2WXbuf wxChar*
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|     #define wxWX2WCbuf wxChar*
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| #else // ANSI
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|     #define wxMB2WXbuf wxChar*
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|     #define wxWX2MBbuf wxChar*
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|     #define wxWC2WXbuf wxCharBuffer
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|     #define wxWX2WCbuf wxWCharBuffer
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| #endif // Unicode/ANSI
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| 
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| // ----------------------------------------------------------------------------
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| // A class for holding growable data buffers (not necessarily strings)
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| // ----------------------------------------------------------------------------
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| 
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| // This class manages the actual data buffer pointer and is ref-counted.
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| class wxMemoryBufferData
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| {
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| public:
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|     // the initial size and also the size added by ResizeIfNeeded()
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|     enum { DefBufSize = 1024 };
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| 
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|     friend class wxMemoryBuffer;
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| 
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|     // everyting is private as it can only be used by wxMemoryBuffer
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| private:
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|     wxMemoryBufferData(size_t size = wxMemoryBufferData::DefBufSize)
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|         : m_data(size ? malloc(size) : NULL), m_size(size), m_len(0), m_ref(0)
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|     {
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|     }
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|     ~wxMemoryBufferData() { free(m_data); }
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| 
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| 
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|     void ResizeIfNeeded(size_t newSize)
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|     {
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|         if (newSize > m_size)
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|         {
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|             void *dataOld = m_data;
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|             m_data = realloc(m_data, newSize + wxMemoryBufferData::DefBufSize);
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|             if ( !m_data )
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|             {
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|                 free(dataOld);
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|             }
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| 
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|             m_size = newSize + wxMemoryBufferData::DefBufSize;
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|         }
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|     }
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| 
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|     void IncRef() { m_ref += 1; }
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|     void DecRef()
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|     {
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|         m_ref -= 1;
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|         if (m_ref == 0)  // are there no more references?
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|             delete this;
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|     }
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| 
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| 
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|     // the buffer containing the data
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|     void  *m_data;
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| 
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|     // the size of the buffer
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|     size_t m_size;
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| 
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|     // the amount of data currently in the buffer
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|     size_t m_len;
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| 
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|     // the reference count
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|     size_t m_ref;
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| 
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|     DECLARE_NO_COPY_CLASS(wxMemoryBufferData)
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| };
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| 
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| 
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| class wxMemoryBuffer
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| {
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| public:
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|     // ctor and dtor
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|     wxMemoryBuffer(size_t size = wxMemoryBufferData::DefBufSize)
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|     {
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|         m_bufdata = new wxMemoryBufferData(size);
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|         m_bufdata->IncRef();
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|     }
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| 
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|     ~wxMemoryBuffer() { m_bufdata->DecRef(); }
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| 
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| 
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|     // copy and assignment
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|     wxMemoryBuffer(const wxMemoryBuffer& src)
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|         : m_bufdata(src.m_bufdata)
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|     {
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|         m_bufdata->IncRef();
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|     }
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| 
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|     wxMemoryBuffer& operator=(const wxMemoryBuffer& src)
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|     {
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|         m_bufdata->DecRef();
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|         m_bufdata = src.m_bufdata;
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|         m_bufdata->IncRef();
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|         return *this;
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|     }
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| 
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| 
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|     // Accessors
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|     void  *GetData() const    { return m_bufdata->m_data; }
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|     size_t GetBufSize() const { return m_bufdata->m_size; }
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|     size_t GetDataLen() const { return m_bufdata->m_len; }
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| 
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|     void   SetBufSize(size_t size) { m_bufdata->ResizeIfNeeded(size); }
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|     void   SetDataLen(size_t len)
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|     {
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|         wxASSERT(len <= m_bufdata->m_size);
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|         m_bufdata->m_len = len;
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|     }
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| 
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|     // Ensure the buffer is big enough and return a pointer to it
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|     void *GetWriteBuf(size_t sizeNeeded)
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|     {
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|         m_bufdata->ResizeIfNeeded(sizeNeeded);
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|         return m_bufdata->m_data;
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|     }
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| 
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|     // Update the length after the write
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|     void  UngetWriteBuf(size_t sizeUsed) { SetDataLen(sizeUsed); }
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| 
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|     // Like the above, but appends to the buffer
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|     void *GetAppendBuf(size_t sizeNeeded)
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|     {
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|         m_bufdata->ResizeIfNeeded(m_bufdata->m_len + sizeNeeded);
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|         return (char*)m_bufdata->m_data + m_bufdata->m_len;
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|     }
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| 
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|     // Update the length after the append
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|     void  UngetAppendBuf(size_t sizeUsed)
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|     {
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|         SetDataLen(m_bufdata->m_len + sizeUsed);
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|     }
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| 
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|     // Other ways to append to the buffer
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|     void  AppendByte(char data)
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|     {
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|         wxCHECK_RET( m_bufdata->m_data, _T("invalid wxMemoryBuffer") );
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| 
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|         m_bufdata->ResizeIfNeeded(m_bufdata->m_len + 1);
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|         *(((char*)m_bufdata->m_data) + m_bufdata->m_len) = data;
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|         m_bufdata->m_len += 1;
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|     }
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| 
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|     void  AppendData(const void *data, size_t len)
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|     {
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|         memcpy(GetAppendBuf(len), data, len);
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|         UngetAppendBuf(len);
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|     }
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| 
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|     operator const char *() const { return (const char*)GetData(); }
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| 
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| private:
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|     wxMemoryBufferData*  m_bufdata;
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| };
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| 
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| // ----------------------------------------------------------------------------
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| // template class for any kind of data
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| // ----------------------------------------------------------------------------
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| 
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| // TODO
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| 
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| #endif // _WX_BUFFER_H
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