ReactOS 0.4.15-dev-8339-g4028de8
_streambuf.h
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1/*
2 * Copyright (c) 1999
3 * Silicon Graphics Computer Systems, Inc.
4 *
5 * Copyright (c) 1999
6 * Boris Fomitchev
7 *
8 * This material is provided "as is", with absolutely no warranty expressed
9 * or implied. Any use is at your own risk.
10 *
11 * Permission to use or copy this software for any purpose is hereby granted
12 * without fee, provided the above notices are retained on all copies.
13 * Permission to modify the code and to distribute modified code is granted,
14 * provided the above notices are retained, and a notice that the code was
15 * modified is included with the above copyright notice.
16 *
17 */
18#ifndef _STLP_INTERNAL_STREAMBUF
19#define _STLP_INTERNAL_STREAMBUF
20
21#ifndef _STLP_IOS_BASE_H
22# include <stl/_ios_base.h> // Needed for ios_base bitfield members.
23#endif // <ios_base> includes <iosfwd>.
24
26
27//----------------------------------------------------------------------
28// Class basic_streambuf<>, the base class of the streambuf hierarchy.
29
30// A basic_streambuf<> manages an input (get) area and an output (put)
31// area. Each is described by three pointers: a beginning, an end, and a
32// current position. basic_streambuf<> contains some very simple member
33// functions that manipulate those six pointers, but almost all of the real
34// functionality gets delegated to protected virtual member functions.
35// All of the public member functions are inline, and most of the protected
36// member functions are virtual.
37
38// Although basic_streambuf<> is not abstract, it is useful only as a base
39// class. Its virtual member functions have default definitions such that
40// reading from a basic_streambuf<> will always yield EOF, and writing to a
41// basic_streambuf<> will always fail.
42
43// The second template parameter, _Traits, defaults to char_traits<_CharT>.
44// The default is declared in header <iosfwd>, and it isn't declared here
45// because C++ language rules do not allow it to be declared twice.
46
47template <class _CharT, class _Traits>
49 friend class basic_istream<_CharT, _Traits>;
50 friend class basic_ostream<_CharT, _Traits>;
51
52public: // Typedefs.
53 typedef _CharT char_type;
54 typedef typename _Traits::int_type int_type;
55 typedef typename _Traits::pos_type pos_type;
56 typedef typename _Traits::off_type off_type;
57 typedef _Traits traits_type;
58
59private: // Data members.
60
61 char_type* _M_gbegin; // Beginning of get area
62 char_type* _M_gnext; // Current position within the get area
63 char_type* _M_gend; // End of get area
64
65 char_type* _M_pbegin; // Beginning of put area
66 char_type* _M_pnext; // Current position within the put area
67 char_type* _M_pend; // End of put area
68
69 locale _M_locale; // The streambuf's locale object
70
71public: // Destructor.
72 virtual ~basic_streambuf();
73
74protected: // The default constructor.
76#if defined (_STLP_MSVC) && (_STLP_MSVC < 1300) && defined (_STLP_USE_STATIC_LIB)
77 //We make it inline to avoid unresolved symbol.
78 : _M_gbegin(0), _M_gnext(0), _M_gend(0),
79 _M_pbegin(0), _M_pnext(0), _M_pend(0),
80 _M_locale()
81 {}
82#else
83 ;
84#endif
85
86protected: // Protected interface to the get area.
87 char_type* eback() const { return _M_gbegin; } // Beginning
88 char_type* gptr() const { return _M_gnext; } // Current position
89 char_type* egptr() const { return _M_gend; } // End
90
91 void gbump(int __n) { _M_gnext += __n; }
92 void setg(char_type* __gbegin, char_type* __gnext, char_type* __gend) {
93 _M_gbegin = __gbegin;
94 _M_gnext = __gnext;
95 _M_gend = __gend;
96 }
97
98public:
99 // An alternate public interface to the above functions
100 // which allows us to avoid using templated friends which
101 // are not supported on some compilers.
102 char_type* _M_eback() const { return eback(); }
103 char_type* _M_gptr() const { return gptr(); }
104 char_type* _M_egptr() const { return egptr(); }
105 void _M_gbump(int __n) { gbump(__n); }
106 void _M_setg(char_type* __gbegin, char_type* __gnext, char_type* __gend)
107 { this->setg(__gbegin, __gnext, __gend); }
108
109protected: // Protected interface to the put area
110
111 char_type* pbase() const { return _M_pbegin; } // Beginning
112 char_type* pptr() const { return _M_pnext; } // Current position
113 char_type* epptr() const { return _M_pend; } // End
114
115 void pbump(int __n) { _M_pnext += __n; }
116 void setp(char_type* __pbegin, char_type* __pend) {
117 _M_pbegin = __pbegin;
118 _M_pnext = __pbegin;
119 _M_pend = __pend;
120 }
121
122protected: // Virtual buffer management functions.
123
125
126 // Alters the stream position, using an integer offset. In this
127 // class seekoff does nothing; subclasses are expected to override it.
129 ios_base::openmode = ios_base::in | ios_base::out);
130
131 // Alters the stream position, using a previously obtained streampos. In
132 // this class seekpos does nothing; subclasses are expected to override it.
133 virtual pos_type
134 seekpos(pos_type, ios_base::openmode = ios_base::in | ios_base::out);
135
136 // Synchronizes (i.e. flushes) the buffer. All subclasses are expected to
137 // override this virtual member function.
138 virtual int sync();
139
140
141public: // Buffer management.
143 { return this->setbuf(__s, __n); }
144
146 ios_base::openmode __mod = ios_base::in | ios_base::out)
147 { return this->seekoff(__offset, __way, __mod); }
148
150 ios_base::openmode __mod = ios_base::in | ios_base::out)
151 { return this->seekpos(__sp, __mod); }
152
153 int pubsync() { return this->sync(); }
154
155protected: // Virtual get area functions, as defined in
156 // 17.5.2.4.3 and 17.5.2.4.4 of the standard.
157 // Returns a lower bound on the number of characters that we can read,
158 // with underflow, before reaching end of file. (-1 is a special value:
159 // it means that underflow will fail.) Most subclasses should probably
160 // override this virtual member function.
161 virtual streamsize showmanyc();
162
163 // Reads up to __n characters. Return value is the number of
164 // characters read.
166
167 // Called when there is no read position, i.e. when gptr() is null
168 // or when gptr() >= egptr(). Subclasses are expected to override
169 // this virtual member function.
170 virtual int_type underflow();
171
172 // Similar to underflow(), but used for unbuffered input. Most
173 // subclasses should probably override this virtual member function.
174 virtual int_type uflow();
175
176 // Called when there is no putback position, i.e. when gptr() is null
177 // or when gptr() == eback(). All subclasses are expected to override
178 // this virtual member function.
179 virtual int_type pbackfail(int_type = traits_type::eof());
180
181protected: // Virtual put area functions, as defined in
182 // 27.5.2.4.5 of the standard.
183
184 // Writes up to __n characters. Return value is the number of characters
185 // written.
186 virtual streamsize xsputn(const char_type* __s, streamsize __n);
187
188 // Extension: writes up to __n copies of __c. Return value is the number
189 // of characters written.
191
192 // Called when there is no write position. All subclasses are expected to
193 // override this virtual member function.
194 virtual int_type overflow(int_type = traits_type::eof());
195
196public: // Public members for writing characters.
197 // Write a single character.
199 return ((_M_pnext < _M_pend) ? _Traits::to_int_type(*_M_pnext++ = __c)
200 : this->overflow(_Traits::to_int_type(__c)));
201 }
202
203 // Write __n characters.
205 { return this->xsputn(__s, __n); }
206
207 // Extension: write __n copies of __c.
209 { return this->_M_xsputnc(__c, __n); }
210
211private: // Helper functions.
213
214public: // Public members for reading characters.
216 return (_M_gnext < _M_gend) ? (_M_gend - _M_gnext) : this->showmanyc();
217 }
218
219 // Advance to the next character and return it.
220 int_type snextc() {
221 return ( _M_gend - _M_gnext > 1 ?
222 _Traits::to_int_type(*++_M_gnext) :
223 this->_M_snextc_aux());
224 }
225
226 // Return the current character and advance to the next.
227 int_type sbumpc() {
228 return _M_gnext < _M_gend ? _Traits::to_int_type(*_M_gnext++)
229 : this->uflow();
230 }
231
232 // Return the current character without advancing to the next.
233 int_type sgetc() {
234 return _M_gnext < _M_gend ? _Traits::to_int_type(*_M_gnext)
235 : this->underflow();
236 }
237
239 { return this->xsgetn(__s, __n); }
240
242 return ((_M_gbegin < _M_gnext) && _Traits::eq(__c, *(_M_gnext - 1)))
243 ? _Traits::to_int_type(*--_M_gnext)
244 : this->pbackfail(_Traits::to_int_type(__c));
245 }
246
248 return (_M_gbegin < _M_gnext)
249 ? _Traits::to_int_type(*--_M_gnext)
250 : this->pbackfail();
251 }
252
253protected: // Virtual locale functions.
254
255 // This is a hook, called by pubimbue() just before pubimbue()
256 // sets the streambuf's locale to __loc. Note that imbue should
257 // not (and cannot, since it has no access to streambuf's private
258 // members) set the streambuf's locale itself.
259 virtual void imbue(const locale&);
260
261public: // Locale-related functions.
262 locale pubimbue(const locale&);
263 locale getloc() const { return _M_locale; }
264
265#if !defined (_STLP_NO_ANACHRONISMS)
266 void stossc() { this->sbumpc(); }
267#endif
268};
269
270#if defined (_STLP_USE_TEMPLATE_EXPORT)
272# if !defined (_STLP_NO_WCHAR_T)
274# endif // _STLP_NO_WCHAR_T
275#endif // _STLP_USE_TEMPLATE_EXPORT
276
278
279#if defined (_STLP_EXPOSE_STREAM_IMPLEMENTATION) && !defined (_STLP_LINK_TIME_INSTANTIATION)
280# include <stl/_streambuf.c>
281#endif
282
283#endif
284
285// Local Variables:
286// mode:C++
287// End:
return __n
Definition: _algo.h:75
ptrdiff_t streamsize
Definition: char_traits.h:81
char_type * _M_pbegin
Definition: _streambuf.h:65
char_type * pbase() const
Definition: _streambuf.h:111
streamsize _M_sputnc(char_type __c, streamsize __n)
Definition: _streambuf.h:208
_CharT char_type
Definition: _streambuf.h:53
virtual pos_type seekoff(off_type, ios_base::seekdir, ios_base::openmode=ios_base::in|ios_base::out)
Definition: _streambuf.c:193
char_type * _M_eback() const
Definition: _streambuf.h:102
char_type * _M_egptr() const
Definition: _streambuf.h:104
char_type * epptr() const
Definition: _streambuf.h:113
virtual streamsize xsputn(const char_type *__s, streamsize __n)
Definition: _streambuf.c:84
int_type snextc()
Definition: _streambuf.h:220
virtual int_type uflow()
Definition: _streambuf.c:162
void _M_gbump(int __n)
Definition: _streambuf.h:105
virtual streamsize _M_xsputnc(char_type __c, streamsize __n)
Definition: _streambuf.c:112
streamsize sgetn(char_type *__s, streamsize __n)
Definition: _streambuf.h:238
int_type sputbackc(char_type __c)
Definition: _streambuf.h:241
locale _M_locale
Definition: _streambuf.h:69
virtual void imbue(const locale &)
Definition: _streambuf.c:180
_Traits traits_type
Definition: _streambuf.h:57
virtual int_type underflow()
Definition: _streambuf.c:170
locale getloc() const
Definition: _streambuf.h:263
pos_type pubseekoff(off_type __offset, ios_base::seekdir __way, ios_base::openmode __mod=ios_base::in|ios_base::out)
Definition: _streambuf.h:145
char_type * egptr() const
Definition: _streambuf.h:89
virtual streamsize xsgetn(char_type *__s, streamsize __n)
Definition: _streambuf.c:54
char_type * gptr() const
Definition: _streambuf.h:88
void pbump(int __n)
Definition: _streambuf.h:115
char_type * _M_gptr() const
Definition: _streambuf.h:103
locale pubimbue(const locale &)
Definition: _streambuf.c:45
void setp(char_type *__pbegin, char_type *__pend)
Definition: _streambuf.h:116
basic_streambuf< _CharT, _Traits > * pubsetbuf(char_type *__s, streamsize __n)
Definition: _streambuf.h:142
int_type _M_snextc_aux()
Definition: _streambuf.c:137
virtual int_type pbackfail(int_type=traits_type::eof())
Definition: _streambuf.c:150
virtual pos_type seekpos(pos_type, ios_base::openmode=ios_base::in|ios_base::out)
Definition: _streambuf.c:188
_Traits::off_type off_type
Definition: _streambuf.h:56
pos_type pubseekpos(pos_type __sp, ios_base::openmode __mod=ios_base::in|ios_base::out)
Definition: _streambuf.h:149
virtual ~basic_streambuf()
Definition: _streambuf.c:40
char_type * _M_gnext
Definition: _streambuf.h:62
int_type sbumpc()
Definition: _streambuf.h:227
char_type * _M_pend
Definition: _streambuf.h:67
virtual int_type overflow(int_type=traits_type::eof())
Definition: _streambuf.c:156
virtual streamsize showmanyc()
Definition: _streambuf.c:175
int_type sgetc()
Definition: _streambuf.h:233
streamsize in_avail()
Definition: _streambuf.h:215
virtual int sync()
Definition: _streambuf.c:184
_Traits::pos_type pos_type
Definition: _streambuf.h:55
void setg(char_type *__gbegin, char_type *__gnext, char_type *__gend)
Definition: _streambuf.h:92
char_type * _M_gbegin
Definition: _streambuf.h:61
char_type * eback() const
Definition: _streambuf.h:87
_Traits::int_type int_type
Definition: _streambuf.h:54
char_type * pptr() const
Definition: _streambuf.h:112
char_type * _M_pnext
Definition: _streambuf.h:66
void _M_setg(char_type *__gbegin, char_type *__gnext, char_type *__gend)
Definition: _streambuf.h:106
char_type * _M_gend
Definition: _streambuf.h:63
void gbump(int __n)
Definition: _streambuf.h:91
virtual basic_streambuf< _CharT, _Traits > * setbuf(char_type *, streamsize)
Definition: _streambuf.c:199
streamsize sputn(const char_type *__s, streamsize __n)
Definition: _streambuf.h:204
int_type sputc(char_type __c)
Definition: _streambuf.h:198
int_type sungetc()
Definition: _streambuf.h:247
int openmode
Definition: _ios_base.h:59
int seekdir
Definition: _ios_base.h:60
Definition: _locale.h:75
#define _STLP_EXPORT_TEMPLATE_CLASS
Definition: features.h:987
#define _STLP_BEGIN_NAMESPACE
Definition: features.h:501
#define _STLP_END_NAMESPACE
Definition: features.h:503
#define __c
Definition: schilyio.h:209