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added ctor for wxChar/WCharBuffer from wxCStrData in ANSI/Unicode build to make it...
[wxWidgets.git] / include / wx / buffer.h
1 ///////////////////////////////////////////////////////////////////////////////
2 // Name: wx/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 licence
10 ///////////////////////////////////////////////////////////////////////////////
11
12 #ifndef _WX_BUFFER_H
13 #define _WX_BUFFER_H
14
15 #include "wx/wxchar.h"
16
17 #include <stdlib.h> // malloc() and free()
18
19 // ----------------------------------------------------------------------------
20 // Special classes for (wide) character strings: they use malloc/free instead
21 // of new/delete
22 // ----------------------------------------------------------------------------
23
24 #define DEFINE_BUFFER(classname, chartype, strdupfunc) \
25 class WXDLLIMPEXP_BASE classname \
26 { \
27 public: \
28 classname(const chartype *str = NULL) \
29 : m_str(str ? strdupfunc(str) : NULL) \
30 { \
31 } \
32 \
33 classname(const wxCStrData& cstr); \
34 \
35 classname(size_t len) \
36 : m_str((chartype *)malloc((len + 1)*sizeof(chartype))) \
37 { \
38 m_str[len] = (chartype)0; \
39 } \
40 \
41 /* no need to check for NULL, free() does it */ \
42 ~classname() { free(m_str); } \
43 \
44 /* \
45 WARNING: \
46 \
47 the copy ctor and assignment operators change the passed in object \
48 even although it is declared as "const", so: \
49 \
50 a) it shouldn't be really const \
51 b) you shouldn't use it afterwards (or know that it was reset) \
52 \
53 This is very ugly but is unfortunately needed to make the normal use\
54 of classname buffer objects possible and is very similar to what \
55 std::auto_ptr<> does (as if it were an excuse...) \
56 */ \
57 \
58 /* \
59 because of the remark above, release() is declared const even if it \
60 isn't really const \
61 */ \
62 chartype *release() const \
63 { \
64 chartype *p = m_str; \
65 ((classname *)this)->m_str = NULL; \
66 return p; \
67 } \
68 \
69 void reset() \
70 { \
71 free(m_str); \
72 m_str = NULL; \
73 } \
74 \
75 classname(const classname& src) \
76 : m_str(src.release()) \
77 { \
78 } \
79 \
80 classname& operator=(const chartype *str) \
81 { \
82 free(m_str); \
83 m_str = str ? strdupfunc(str) : NULL; \
84 return *this; \
85 } \
86 \
87 classname& operator=(const classname& src) \
88 { \
89 free(m_str); \
90 m_str = src.release(); \
91 \
92 return *this; \
93 } \
94 \
95 bool extend(size_t len) \
96 { \
97 chartype * \
98 str = (chartype *)realloc(m_str, (len + 1)*sizeof(chartype)); \
99 if ( !str ) \
100 return false; \
101 \
102 m_str = str; \
103 \
104 return true; \
105 } \
106 \
107 chartype *data() { return m_str; } \
108 const chartype *data() const { return m_str; } \
109 operator const chartype *() const { return m_str; } \
110 chartype operator[](size_t n) const { return m_str[n]; } \
111 \
112 private: \
113 chartype *m_str; \
114 }
115
116 DEFINE_BUFFER(wxCharBuffer, char, wxStrdupA);
117
118 #if wxUSE_WCHAR_T
119
120 DEFINE_BUFFER(wxWCharBuffer, wchar_t, wxStrdupW);
121
122 #endif // wxUSE_WCHAR_T
123
124 #undef DEFINE_BUFFER
125
126 #if wxUSE_UNICODE
127 typedef wxWCharBuffer wxWxCharBuffer;
128
129 #define wxMB2WXbuf wxWCharBuffer
130 #define wxWX2MBbuf wxCharBuffer
131 #define wxWC2WXbuf wxChar*
132 #define wxWX2WCbuf wxChar*
133 #else // ANSI
134 typedef wxCharBuffer wxWxCharBuffer;
135
136 #define wxMB2WXbuf wxChar*
137 #define wxWX2MBbuf wxChar*
138 #define wxWC2WXbuf wxCharBuffer
139 #define wxWX2WCbuf wxWCharBuffer
140 #endif // Unicode/ANSI
141
142 // ----------------------------------------------------------------------------
143 // A class for holding growable data buffers (not necessarily strings)
144 // ----------------------------------------------------------------------------
145
146 // This class manages the actual data buffer pointer and is ref-counted.
147 class wxMemoryBufferData
148 {
149 public:
150 // the initial size and also the size added by ResizeIfNeeded()
151 enum { DefBufSize = 1024 };
152
153 friend class wxMemoryBuffer;
154
155 // everyting is private as it can only be used by wxMemoryBuffer
156 private:
157 wxMemoryBufferData(size_t size = wxMemoryBufferData::DefBufSize)
158 : m_data(size ? malloc(size) : NULL), m_size(size), m_len(0), m_ref(0)
159 {
160 }
161 ~wxMemoryBufferData() { free(m_data); }
162
163
164 void ResizeIfNeeded(size_t newSize)
165 {
166 if (newSize > m_size)
167 {
168 void *dataOld = m_data;
169 m_data = realloc(m_data, newSize + wxMemoryBufferData::DefBufSize);
170 if ( !m_data )
171 {
172 free(dataOld);
173 }
174
175 m_size = newSize + wxMemoryBufferData::DefBufSize;
176 }
177 }
178
179 void IncRef() { m_ref += 1; }
180 void DecRef()
181 {
182 m_ref -= 1;
183 if (m_ref == 0) // are there no more references?
184 delete this;
185 }
186
187
188 // the buffer containing the data
189 void *m_data;
190
191 // the size of the buffer
192 size_t m_size;
193
194 // the amount of data currently in the buffer
195 size_t m_len;
196
197 // the reference count
198 size_t m_ref;
199
200 DECLARE_NO_COPY_CLASS(wxMemoryBufferData)
201 };
202
203
204 class wxMemoryBuffer
205 {
206 public:
207 // ctor and dtor
208 wxMemoryBuffer(size_t size = wxMemoryBufferData::DefBufSize)
209 {
210 m_bufdata = new wxMemoryBufferData(size);
211 m_bufdata->IncRef();
212 }
213
214 ~wxMemoryBuffer() { m_bufdata->DecRef(); }
215
216
217 // copy and assignment
218 wxMemoryBuffer(const wxMemoryBuffer& src)
219 : m_bufdata(src.m_bufdata)
220 {
221 m_bufdata->IncRef();
222 }
223
224 wxMemoryBuffer& operator=(const wxMemoryBuffer& src)
225 {
226 m_bufdata->DecRef();
227 m_bufdata = src.m_bufdata;
228 m_bufdata->IncRef();
229 return *this;
230 }
231
232
233 // Accessors
234 void *GetData() const { return m_bufdata->m_data; }
235 size_t GetBufSize() const { return m_bufdata->m_size; }
236 size_t GetDataLen() const { return m_bufdata->m_len; }
237
238 void SetBufSize(size_t size) { m_bufdata->ResizeIfNeeded(size); }
239 void SetDataLen(size_t len)
240 {
241 wxASSERT(len <= m_bufdata->m_size);
242 m_bufdata->m_len = len;
243 }
244
245 // Ensure the buffer is big enough and return a pointer to it
246 void *GetWriteBuf(size_t sizeNeeded)
247 {
248 m_bufdata->ResizeIfNeeded(sizeNeeded);
249 return m_bufdata->m_data;
250 }
251
252 // Update the length after the write
253 void UngetWriteBuf(size_t sizeUsed) { SetDataLen(sizeUsed); }
254
255 // Like the above, but appends to the buffer
256 void *GetAppendBuf(size_t sizeNeeded)
257 {
258 m_bufdata->ResizeIfNeeded(m_bufdata->m_len + sizeNeeded);
259 return (char*)m_bufdata->m_data + m_bufdata->m_len;
260 }
261
262 // Update the length after the append
263 void UngetAppendBuf(size_t sizeUsed)
264 {
265 SetDataLen(m_bufdata->m_len + sizeUsed);
266 }
267
268 // Other ways to append to the buffer
269 void AppendByte(char data)
270 {
271 wxCHECK_RET( m_bufdata->m_data, _T("invalid wxMemoryBuffer") );
272
273 m_bufdata->ResizeIfNeeded(m_bufdata->m_len + 1);
274 *(((char*)m_bufdata->m_data) + m_bufdata->m_len) = data;
275 m_bufdata->m_len += 1;
276 }
277
278 void AppendData(const void *data, size_t len)
279 {
280 memcpy(GetAppendBuf(len), data, len);
281 UngetAppendBuf(len);
282 }
283
284 operator const char *() const { return (const char*)GetData(); }
285
286 private:
287 wxMemoryBufferData* m_bufdata;
288 };
289
290 // ----------------------------------------------------------------------------
291 // template class for any kind of data
292 // ----------------------------------------------------------------------------
293
294 // TODO
295
296 #endif // _WX_BUFFER_H
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