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git.saurik.com Git - wxWidgets.git/blob - include/wx/buffer.h
1 ///////////////////////////////////////////////////////////////////////////////
3 // Purpose: auto buffer classes: buffers which automatically free memory
4 // Author: Vadim Zeitlin
8 // Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
9 // Licence: wxWindows license
10 ///////////////////////////////////////////////////////////////////////////////
12 // these classes are for private use only for now, they're not documented
17 #include "wx/wxchar.h"
19 // ----------------------------------------------------------------------------
20 // Special classes for (wide) character strings: they use malloc/free instead
22 // ----------------------------------------------------------------------------
24 #define DEFINE_BUFFER(classname, chartype, strdupfunc) \
28 classname(const chartype *str) \
29 : m_str(str ? strdupfunc(str) : NULL) \
33 classname(size_t len) \
34 : m_str((chartype *)malloc((len + 1)*sizeof(chartype))) \
36 m_str[len] = (chartype)0; \
39 /* no need to check for NULL, free() does it */ \
40 ~classname() { free(m_str); } \
45 the copy ctor and assignment operators change the passed in object \
46 even although it is declared as "const", so: \
48 a) it shouldn't be really const \
49 b) you shouldn't use it afterwards (or know that it was reset) \
51 This is very ugly but is unfortunately needed to make the normal use\
52 of classname buffer objects possible and is very similar to what \
53 std::auto_ptr<> does (as if it were an excuse...) \
57 because of the remark above, release() is declared const even if it \
60 chartype *release() const \
62 chartype *p = m_str; \
63 ((classname *)this)->m_str = NULL; \
67 classname(const classname& src) \
68 : m_str(src.release()) \
72 classname& operator=(const chartype *str) \
75 m_str = str ? strdupfunc(str) : NULL; \
79 classname& operator=(const classname& src) \
82 m_str = src.release(); \
87 chartype *data() { return m_str; } \
88 const chartype *data() const { return m_str; } \
89 operator const chartype *() const { return m_str; } \
90 chartype operator[](size_t n) const { return m_str[n]; } \
96 DEFINE_BUFFER(wxCharBuffer
, char, wxStrdupA
);
100 DEFINE_BUFFER(wxWCharBuffer
, wchar_t, wxStrdupW
);
102 #endif // wxUSE_WCHAR_T
107 #define wxMB2WXbuf wxWCharBuffer
108 #define wxWX2MBbuf wxCharBuffer
109 #define wxWC2WXbuf wxChar*
110 #define wxWX2WCbuf wxChar*
112 #define wxMB2WXbuf wxChar*
113 #define wxWX2MBbuf wxChar*
114 #define wxWC2WXbuf wxCharBuffer
115 #define wxWX2WCbuf wxWCharBuffer
116 #endif // Unicode/ANSI
118 // ----------------------------------------------------------------------------
119 // A class for holding growable data buffers (not necessarily strings)
120 // ----------------------------------------------------------------------------
122 // This class manages the actual data buffer pointer and is ref-counted.
123 class wxMemoryBufferData
126 // the initial size and also the size added by ResizeIfNeeded()
127 enum { BLOCK_SIZE
= 1024 };
129 friend class wxMemoryBuffer
;
131 // everyting is private as it can only be used by wxMemoryBuffer
133 wxMemoryBufferData(size_t size
= wxMemoryBufferData::BLOCK_SIZE
)
134 : m_data(size
? malloc(size
) : NULL
), m_size(size
), m_len(0), m_ref(0)
137 ~wxMemoryBufferData() { free(m_data
); }
140 void ResizeIfNeeded(size_t newSize
)
142 if (newSize
> m_size
)
144 void *dataOld
= m_data
;
145 m_data
= realloc(m_data
, newSize
+ wxMemoryBufferData::BLOCK_SIZE
);
151 m_size
= newSize
+ wxMemoryBufferData::BLOCK_SIZE
;
155 void IncRef() { m_ref
+= 1; }
159 if (m_ref
== 0) // are there no more references?
164 // the buffer containing the data
167 // the size of the buffer
170 // the amount of data currently in the buffer
173 // the reference count
182 wxMemoryBuffer(size_t size
= wxMemoryBufferData::BLOCK_SIZE
)
184 m_bufdata
= new wxMemoryBufferData(size
);
188 ~wxMemoryBuffer() { m_bufdata
->DecRef(); }
191 // copy and assignment
192 wxMemoryBuffer(const wxMemoryBuffer
& src
)
193 : m_bufdata(src
.m_bufdata
)
198 wxMemoryBuffer
& operator=(const wxMemoryBuffer
& src
)
201 m_bufdata
= src
.m_bufdata
;
208 void *GetData() const { return m_bufdata
->m_data
; }
209 size_t GetBufSize() const { return m_bufdata
->m_size
; }
210 size_t GetDataLen() const { return m_bufdata
->m_len
; }
212 void SetBufSize(size_t size
) { m_bufdata
->ResizeIfNeeded(size
); }
213 void SetDataLen(size_t len
)
215 wxASSERT(len
<= m_bufdata
->m_size
);
216 m_bufdata
->m_len
= len
;
219 // Ensure the buffer is big enough and return a pointer to it
220 void *GetWriteBuf(size_t sizeNeeded
)
222 m_bufdata
->ResizeIfNeeded(sizeNeeded
);
223 return m_bufdata
->m_data
;
226 // Update the length after the write
227 void UngetWriteBuf(size_t sizeUsed
) { SetDataLen(sizeUsed
); }
229 // Like the above, but appends to the buffer
230 void *GetAppendBuf(size_t sizeNeeded
)
232 m_bufdata
->ResizeIfNeeded(m_bufdata
->m_len
+ sizeNeeded
);
233 return (char*)m_bufdata
->m_data
+ m_bufdata
->m_len
;
236 // Update the length after the append
237 void UngetAppendBuf(size_t sizeUsed
)
239 SetDataLen(m_bufdata
->m_len
+ sizeUsed
);
242 // Other ways to append to the buffer
243 void AppendByte(char data
)
245 wxCHECK_RET( m_bufdata
->m_data
, _T("invalid wxMemoryBuffer") );
247 m_bufdata
->ResizeIfNeeded(m_bufdata
->m_len
+ 1);
248 *(((char*)m_bufdata
->m_data
) + m_bufdata
->m_len
) = data
;
249 m_bufdata
->m_len
+= 1;
252 void AppendData(void* data
, size_t len
)
254 memcpy(GetAppendBuf(len
), data
, len
);
258 operator const char *() const { return (const char*)GetData(); }
261 wxMemoryBufferData
* m_bufdata
;
264 // ----------------------------------------------------------------------------
265 // template class for any kind of data
266 // ----------------------------------------------------------------------------
270 #endif // _WX_BUFFER_H