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