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/project/jni/stlport/stlport/stl/_streambuf.h

https://github.com/aichunyu/FFPlayer
C Header | 301 lines | 159 code | 62 blank | 80 comment | 6 complexity | d5205f0ad12c52461baebb9597dbe2d3 MD5 | raw file
  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
 25_STLP_BEGIN_NAMESPACE
 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>
 48class basic_streambuf {
 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
 71//public:                         // Extension: locking, for thread safety.
 72//  _STLP_mutex _M_lock;
 73
 74public:                         // Destructor.
 75  virtual ~basic_streambuf();
 76
 77protected:                      // The default constructor.
 78  basic_streambuf()
 79#if defined (_STLP_MSVC) && (_STLP_MSVC < 1300) && defined (_STLP_USE_STATIC_LIB)
 80    //We make it inline to avoid unresolved symbol.
 81    : _M_gbegin(0), _M_gnext(0), _M_gend(0),
 82      _M_pbegin(0), _M_pnext(0), _M_pend(0),
 83      _M_locale()
 84  {}
 85#else
 86  ;
 87#endif
 88
 89protected:                      // Protected interface to the get area.
 90  char_type* eback() const { return _M_gbegin; } // Beginning
 91  char_type* gptr()  const { return _M_gnext; }  // Current position
 92  char_type* egptr() const { return _M_gend; }   // End
 93
 94  void gbump(int __n) { _M_gnext += __n; }
 95  void setg(char_type* __gbegin, char_type* __gnext, char_type* __gend) {
 96    _M_gbegin = __gbegin;
 97    _M_gnext  = __gnext;
 98    _M_gend   = __gend;
 99  }
100
101public:
102  // An alternate public interface to the above functions
103  // which allows us to avoid using templated friends which
104  // are not supported on some compilers.
105  char_type* _M_eback() const { return eback(); }
106  char_type* _M_gptr()  const { return gptr(); }
107  char_type* _M_egptr() const { return egptr(); }
108  void _M_gbump(int __n)      { gbump(__n); }
109  void _M_setg(char_type* __gbegin, char_type* __gnext, char_type* __gend)
110  { this->setg(__gbegin, __gnext, __gend); }
111
112protected:                      // Protected interface to the put area
113
114  char_type* pbase() const { return _M_pbegin; } // Beginning
115  char_type* pptr()  const { return _M_pnext; }  // Current position
116  char_type* epptr() const { return _M_pend; }   // End
117
118  void pbump(int __n) { _M_pnext += __n; }
119  void setp(char_type* __pbegin, char_type* __pend) {
120    _M_pbegin = __pbegin;
121    _M_pnext  = __pbegin;
122    _M_pend   = __pend;
123  }
124
125protected:                      // Virtual buffer management functions.
126
127  virtual basic_streambuf<_CharT, _Traits>* setbuf(char_type*, streamsize);
128
129  // Alters the stream position, using an integer offset.  In this
130  // class seekoff does nothing; subclasses are expected to override it.
131  virtual pos_type seekoff(off_type, ios_base::seekdir,
132                           ios_base::openmode = ios_base::in | ios_base::out);
133
134  // Alters the stream position, using a previously obtained streampos.  In
135  // this class seekpos does nothing; subclasses are expected to override it.
136  virtual pos_type
137  seekpos(pos_type, ios_base::openmode = ios_base::in | ios_base::out);
138
139  // Synchronizes (i.e. flushes) the buffer.  All subclasses are expected to
140  // override this virtual member function.
141  virtual int sync();
142
143
144public:                         // Buffer management.
145  basic_streambuf<_CharT, _Traits>* pubsetbuf(char_type* __s, streamsize __n)
146  { return this->setbuf(__s, __n); }
147
148  pos_type pubseekoff(off_type __offset, ios_base::seekdir __way,
149                      ios_base::openmode __mod = ios_base::in | ios_base::out)
150  { return this->seekoff(__offset, __way, __mod); }
151
152  pos_type pubseekpos(pos_type __sp,
153                      ios_base::openmode __mod = ios_base::in | ios_base::out)
154  { return this->seekpos(__sp, __mod); }
155
156  int pubsync() { return this->sync(); }
157
158protected:                      // Virtual get area functions, as defined in
159                                // 17.5.2.4.3 and 17.5.2.4.4 of the standard.
160  // Returns a lower bound on the number of characters that we can read,
161  // with underflow, before reaching end of file.  (-1 is a special value:
162  // it means that underflow will fail.)  Most subclasses should probably
163  // override this virtual member function.
164  virtual streamsize showmanyc();
165
166  // Reads up to __n characters.  Return value is the number of
167  // characters read.
168  virtual streamsize xsgetn(char_type* __s, streamsize __n);
169
170  // Called when there is no read position, i.e. when gptr() is null
171  // or when gptr() >= egptr().  Subclasses are expected to override
172  // this virtual member function.
173  virtual int_type underflow();
174
175  // Similar to underflow(), but used for unbuffered input.  Most
176  // subclasses should probably override this virtual member function.
177  virtual int_type uflow();
178
179  // Called when there is no putback position, i.e. when gptr() is null
180  // or when gptr() == eback().  All subclasses are expected to override
181  // this virtual member function.
182  virtual int_type pbackfail(int_type = traits_type::eof());
183
184protected:                      // Virtual put area functions, as defined in
185                                // 27.5.2.4.5 of the standard.
186
187  // Writes up to __n characters.  Return value is the number of characters
188  // written.
189  virtual streamsize xsputn(const char_type* __s, streamsize __n);
190
191  // Extension: writes up to __n copies of __c.  Return value is the number
192  // of characters written.
193  virtual streamsize _M_xsputnc(char_type __c, streamsize __n);
194
195  // Called when there is no write position.  All subclasses are expected to
196  // override this virtual member function.
197  virtual int_type overflow(int_type = traits_type::eof());
198
199public:                         // Public members for writing characters.
200  // Write a single character.
201  int_type sputc(char_type __c) {
202    return ((_M_pnext < _M_pend) ? _Traits::to_int_type(*_M_pnext++ = __c)
203      : this->overflow(_Traits::to_int_type(__c)));
204  }
205
206  // Write __n characters.
207  streamsize sputn(const char_type* __s, streamsize __n)
208  { return this->xsputn(__s, __n); }
209
210  // Extension: write __n copies of __c.
211  streamsize _M_sputnc(char_type __c, streamsize __n)
212  { return this->_M_xsputnc(__c, __n); }
213
214private:                        // Helper functions.
215  int_type _M_snextc_aux();
216
217public:                         // Public members for reading characters.
218  streamsize in_avail() {
219    return (_M_gnext < _M_gend) ? (_M_gend - _M_gnext) : this->showmanyc();
220  }
221
222  // Advance to the next character and return it.
223  int_type snextc() {
224  return ( _M_gend - _M_gnext > 1 ?
225             _Traits::to_int_type(*++_M_gnext) :
226             this->_M_snextc_aux());
227  }
228
229  // Return the current character and advance to the next.
230  int_type sbumpc() {
231    return _M_gnext < _M_gend ? _Traits::to_int_type(*_M_gnext++)
232      : this->uflow();
233  }
234
235  // Return the current character without advancing to the next.
236  int_type sgetc() {
237    return _M_gnext < _M_gend ? _Traits::to_int_type(*_M_gnext)
238      : this->underflow();
239  }
240
241  streamsize sgetn(char_type* __s, streamsize __n)
242  { return this->xsgetn(__s, __n); }
243
244  int_type sputbackc(char_type __c) {
245    return ((_M_gbegin < _M_gnext) && _Traits::eq(__c, *(_M_gnext - 1)))
246      ? _Traits::to_int_type(*--_M_gnext)
247      : this->pbackfail(_Traits::to_int_type(__c));
248  }
249
250  int_type sungetc() {
251    return (_M_gbegin < _M_gnext)
252      ? _Traits::to_int_type(*--_M_gnext)
253      : this->pbackfail();
254  }
255
256protected:                      // Virtual locale functions.
257
258  // This is a hook, called by pubimbue() just before pubimbue()
259  // sets the streambuf's locale to __loc.  Note that imbue should
260  // not (and cannot, since it has no access to streambuf's private
261  // members) set the streambuf's locale itself.
262  virtual void imbue(const locale&);
263
264public:                         // Locale-related functions.
265  locale pubimbue(const locale&);
266  locale getloc() const { return _M_locale; }
267
268#if !defined (_STLP_NO_ANACHRONISMS)
269  void stossc() { this->sbumpc(); }
270#endif
271#if defined (__MVS__) || defined (__OS400__)
272private: // Data members.
273
274  char_type* _M_gbegin; // Beginning of get area
275  char_type* _M_gnext; // Current position within the get area
276  char_type* _M_gend; // End of get area
277
278  char_type* _M_pbegin; // Beginning of put area
279  char_type* _M_pnext; // Current position within the put area
280  char_type* _M_pend; // End of put area
281#endif
282};
283
284#if defined (_STLP_USE_TEMPLATE_EXPORT)
285_STLP_EXPORT_TEMPLATE_CLASS basic_streambuf<char, char_traits<char> >;
286#  if !defined (_STLP_NO_WCHAR_T)
287_STLP_EXPORT_TEMPLATE_CLASS basic_streambuf<wchar_t, char_traits<wchar_t> >;
288#  endif // _STLP_NO_WCHAR_T
289#endif // _STLP_USE_TEMPLATE_EXPORT
290
291_STLP_END_NAMESPACE
292
293#if defined (_STLP_EXPOSE_STREAM_IMPLEMENTATION) && !defined (_STLP_LINK_TIME_INSTANTIATION)
294#  include <stl/_streambuf.c>
295#endif
296
297#endif
298
299// Local Variables:
300// mode:C++
301// End: