/[pcsx2_0.9.7]/trunk/3rdparty/wxWidgets/src/common/fileback.cpp
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Contents of /trunk/3rdparty/wxWidgets/src/common/fileback.cpp

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Revision 31 - (show annotations) (download)
Tue Sep 7 03:24:11 2010 UTC (10 years, 3 months ago) by william
File size: 8781 byte(s)
committing r3113 initial commit again...
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: src/common/fileback.cpp
3 // Purpose: Back an input stream with memory or a file
4 // Author: Mike Wetherell
5 // RCS-ID: $Id: fileback.cpp 42651 2006-10-29 20:06:45Z MW $
6 // Copyright: (c) 2006 Mike Wetherell
7 // Licence: wxWindows licence
8 /////////////////////////////////////////////////////////////////////////////
9
10 // For compilers that support precompilation, includes "wx.h".
11 #include "wx/wxprec.h"
12
13 #ifdef __BORLANDC__
14 #pragma hdrstop
15 #endif
16
17 #if wxUSE_FILESYSTEM
18
19 #include "wx/private/fileback.h"
20
21 #ifndef WX_PRECOMP
22 #include "wx/utils.h"
23 #include "wx/log.h"
24 #endif
25
26 #include "wx/private/filename.h"
27
28 // Prefer wxFFile unless wxFile has large file support but wxFFile does not.
29 //
30 #if wxUSE_FFILE && (defined wxHAS_LARGE_FFILES || !defined wxHAS_LARGE_FILES)
31 typedef wxFFile wxBFFile;
32 static const bool wxBadSeek = false;
33 #else
34 typedef wxFile wxBFFile;
35 static const wxFileOffset wxBadSeek = wxInvalidOffset;
36 #endif
37
38 /////////////////////////////////////////////////////////////////////////////
39 // Backing file implementation
40
41 class wxBackingFileImpl
42 {
43 public:
44 wxBackingFileImpl(wxInputStream *stream,
45 size_t bufsize,
46 const wxString& prefix);
47 ~wxBackingFileImpl();
48
49 void Release() { if (--m_refcount == 0) delete this; }
50 wxBackingFileImpl *AddRef() { m_refcount++; return this; }
51
52 wxStreamError ReadAt(wxFileOffset pos, void *buffer, size_t *size);
53 wxFileOffset GetLength() const;
54
55 private:
56 int m_refcount;
57
58 wxInputStream *m_stream;
59 wxStreamError m_parenterror;
60
61 char *m_buf;
62 size_t m_bufsize;
63 size_t m_buflen;
64
65 wxString m_prefix;
66 wxString m_filename;
67 wxBFFile m_file;
68 wxFileOffset m_filelen;
69 };
70
71 wxBackingFileImpl::wxBackingFileImpl(wxInputStream *stream,
72 size_t bufsize,
73 const wxString& prefix)
74 : m_refcount(1),
75 m_stream(stream),
76 m_parenterror(wxSTREAM_NO_ERROR),
77 m_buf(NULL),
78 m_bufsize(bufsize),
79 m_buflen(0),
80 m_prefix(prefix),
81 m_filelen(0)
82 {
83 wxFileOffset len = m_stream->GetLength();
84
85 if (len >= 0 && len + size_t(1) < m_bufsize)
86 m_bufsize = size_t(len + 1);
87
88 if (m_bufsize)
89 m_buf = new char[m_bufsize];
90 }
91
92 wxBackingFileImpl::~wxBackingFileImpl()
93 {
94 delete m_stream;
95 delete [] m_buf;
96
97 if (!m_filename.empty())
98 wxRemoveFile(m_filename);
99 }
100
101 wxStreamError wxBackingFileImpl::ReadAt(wxFileOffset pos,
102 void *buffer,
103 size_t *size)
104 {
105 size_t reqestedSize = *size;
106 *size = 0;
107
108 // size1 is the number of bytes it will read directly from the backing
109 // file. size2 is any remaining bytes not yet backed, these are returned
110 // from the buffer or read from the parent stream.
111 size_t size1, size2;
112
113 if (pos + reqestedSize <= m_filelen + size_t(0)) {
114 size1 = reqestedSize;
115 size2 = 0;
116 } else if (pos < m_filelen) {
117 size1 = size_t(m_filelen - pos);
118 size2 = reqestedSize - size1;
119 } else {
120 size1 = 0;
121 size2 = reqestedSize;
122 }
123
124 if (pos < 0)
125 return wxSTREAM_READ_ERROR;
126
127 // read the backing file
128 if (size1) {
129 if (m_file.Seek(pos) == wxBadSeek)
130 return wxSTREAM_READ_ERROR;
131
132 ssize_t n = m_file.Read(buffer, size1);
133 if (n > 0) {
134 *size = n;
135 pos += n;
136 }
137
138 if (*size < size1)
139 return wxSTREAM_READ_ERROR;
140 }
141
142 // read from the buffer or parent stream
143 if (size2)
144 {
145 while (*size < reqestedSize)
146 {
147 // if pos is further ahead than the parent has been read so far,
148 // then read forward in the parent stream
149 while (pos - m_filelen + size_t(0) >= m_buflen)
150 {
151 // if the parent is small enough, don't use a backing file
152 // just the buffer memory
153 if (!m_stream && m_filelen == 0)
154 return m_parenterror;
155
156 // before refilling the buffer write out the current buffer
157 // to the backing file if there is anything in it
158 if (m_buflen)
159 {
160 if (!m_file.IsOpened())
161 if (!wxCreateTempFile(m_prefix, &m_file, &m_filename))
162 return wxSTREAM_READ_ERROR;
163
164 if (m_file.Seek(m_filelen) == wxBadSeek)
165 return wxSTREAM_READ_ERROR;
166
167 size_t count = m_file.Write(m_buf, m_buflen);
168 m_filelen += count;
169
170 if (count < m_buflen) {
171 delete m_stream;
172 m_stream = NULL;
173 if (count > 0) {
174 delete[] m_buf;
175 m_buf = NULL;
176 m_buflen = 0;
177 }
178 m_parenterror = wxSTREAM_READ_ERROR;
179 return m_parenterror;
180 }
181
182 m_buflen = 0;
183
184 if (!m_stream) {
185 delete[] m_buf;
186 m_buf = NULL;
187 }
188 }
189
190 if (!m_stream)
191 return m_parenterror;
192
193 // refill buffer
194 m_buflen = m_stream->Read(m_buf, m_bufsize).LastRead();
195
196 if (m_buflen < m_bufsize) {
197 m_parenterror = m_stream->GetLastError();
198 if (m_parenterror == wxSTREAM_NO_ERROR)
199 m_parenterror = wxSTREAM_EOF;
200 delete m_stream;
201 m_stream = NULL;
202 }
203 }
204
205 // copy to the user's buffer
206 size_t start = size_t(pos - m_filelen);
207 size_t len = wxMin(m_buflen - start, reqestedSize - *size);
208
209 memcpy((char*)buffer + *size, m_buf + start, len);
210 *size += len;
211 pos += len;
212 }
213 }
214
215 return wxSTREAM_NO_ERROR;
216 }
217
218 wxFileOffset wxBackingFileImpl::GetLength() const
219 {
220 if (m_parenterror != wxSTREAM_EOF) {
221 wxLogNull nolog;
222 return m_stream->GetLength();
223 }
224 return m_filelen + m_buflen;
225 }
226
227
228 /////////////////////////////////////////////////////////////////////////////
229 // Backing File, the handle part
230
231 wxBackingFile::wxBackingFile(wxInputStream *stream,
232 size_t bufsize,
233 const wxString& prefix)
234 : m_impl(new wxBackingFileImpl(stream, bufsize, prefix))
235 {
236 }
237
238 wxBackingFile::wxBackingFile(const wxBackingFile& backer)
239 : m_impl(backer.m_impl ? backer.m_impl->AddRef() : NULL)
240 {
241 }
242
243 wxBackingFile& wxBackingFile::operator=(const wxBackingFile& backer)
244 {
245 if (backer.m_impl != m_impl) {
246 if (m_impl)
247 m_impl->Release();
248
249 m_impl = backer.m_impl;
250
251 if (m_impl)
252 m_impl->AddRef();
253 }
254
255 return *this;
256 }
257
258 wxBackingFile::~wxBackingFile()
259 {
260 if (m_impl)
261 m_impl->Release();
262 }
263
264
265 /////////////////////////////////////////////////////////////////////////////
266 // Input stream
267
268 wxBackedInputStream::wxBackedInputStream(const wxBackingFile& backer)
269 : m_backer(backer),
270 m_pos(0)
271 {
272 }
273
274 wxFileOffset wxBackedInputStream::GetLength() const
275 {
276 return m_backer.m_impl->GetLength();
277 }
278
279 wxFileOffset wxBackedInputStream::FindLength() const
280 {
281 wxFileOffset len = GetLength();
282
283 if (len == wxInvalidOffset && IsOk()) {
284 // read a byte at 7ff...ffe
285 wxFileOffset pos = 1;
286 pos <<= sizeof(pos) * 8 - 1;
287 pos = ~pos - 1;
288 char ch;
289 size_t size = 1;
290 m_backer.m_impl->ReadAt(pos, &ch, &size);
291 len = GetLength();
292 }
293
294 return len;
295 }
296
297 size_t wxBackedInputStream::OnSysRead(void *buffer, size_t size)
298 {
299 if (!IsOk())
300 return 0;
301
302 m_lasterror = m_backer.m_impl->ReadAt(m_pos, buffer, &size);
303 m_pos += size;
304 return size;
305 }
306
307 wxFileOffset wxBackedInputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
308 {
309 switch (mode) {
310 case wxFromCurrent:
311 {
312 m_pos += pos;
313 break;
314 }
315 case wxFromEnd:
316 {
317 wxFileOffset len = GetLength();
318 if (len == wxInvalidOffset)
319 return wxInvalidOffset;
320 m_pos = len + pos;
321 break;
322 }
323 default:
324 {
325 m_pos = pos;
326 break;
327 }
328 }
329
330 return m_pos;
331 }
332
333 wxFileOffset wxBackedInputStream::OnSysTell() const
334 {
335 return m_pos;
336 }
337
338 #endif // wxUSE_FILESYSTEM

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