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| // Stream buffer classes -*- C++ -*- |
| |
| // Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 2, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License along |
| // with this library; see the file COPYING. If not, write to the Free |
| // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
| // USA. |
| |
| // As a special exception, you may use this file as part of a free software |
| // library without restriction. Specifically, if other files instantiate |
| // templates or use macros or inline functions from this file, or you compile |
| // this file and link it with other files to produce an executable, this |
| // file does not by itself cause the resulting executable to be covered by |
| // the GNU General Public License. This exception does not however |
| // invalidate any other reasons why the executable file might be covered by |
| // the GNU General Public License. |
| |
| // |
| // ISO C++ 14882: 27.5 Stream buffers |
| // |
| |
| #ifndef _CPP_STREAMBUF |
| #define _CPP_STREAMBUF 1 |
| |
| #pragma GCC system_header |
| |
| #include <bits/c++config.h> |
| #include <bits/std_iosfwd.h> |
| #include <bits/std_cstdio.h> // For SEEK_SET, SEEK_CUR, SEEK_END |
| #include <bits/localefwd.h> |
| #include <bits/ios_base.h> |
| |
| namespace std |
| { |
| template<typename _CharT, typename _Traits> |
| streamsize |
| __copy_streambufs(basic_ios<_CharT, _Traits>& _ios, |
| basic_streambuf<_CharT, _Traits>* __sbin, |
| basic_streambuf<_CharT, _Traits>* __sbout); |
| |
| // 27.5.2 Template class basic_streambuf<_CharT, _Traits> |
| template<typename _CharT, typename _Traits> |
| class basic_streambuf |
| { |
| public: |
| // Types: |
| typedef _CharT char_type; |
| typedef _Traits traits_type; |
| typedef typename traits_type::int_type int_type; |
| typedef typename traits_type::pos_type pos_type; |
| typedef typename traits_type::off_type off_type; |
| |
| // Non-standard Types: |
| typedef ctype<char_type> __ctype_type; |
| typedef basic_streambuf<char_type, traits_type> __streambuf_type; |
| |
| friend class basic_ios<char_type, traits_type>; |
| friend class basic_istream<char_type, traits_type>; |
| friend class basic_ostream<char_type, traits_type>; |
| friend class istreambuf_iterator<char_type, traits_type>; |
| friend class ostreambuf_iterator<char_type, traits_type>; |
| |
| friend streamsize |
| __copy_streambufs<>(basic_ios<char_type, traits_type>& __ios, |
| __streambuf_type* __sbin,__streambuf_type* __sbout); |
| |
| protected: |
| |
| // Pointer to the beginning of internally-allocated |
| // space. Filebuf manually allocates/deallocates this, whereas |
| // stringstreams attempt to use the built-in intelligence of the |
| // string class. If you are managing memory, set this. If not, |
| // leave it NULL. |
| char_type* _M_buf; |
| |
| // Actual size of allocated internal buffer, in bytes. |
| int_type _M_buf_size; |
| |
| // Optimal or preferred size of internal buffer, in bytes. |
| int_type _M_buf_size_opt; |
| |
| // True iff _M_in_* and _M_out_* buffers should always point to |
| // the same place. True for fstreams, false for sstreams. |
| bool _M_buf_unified; |
| |
| // This is based on _IO_FILE, just reordered to be more |
| // consistent, and is intended to be the most minimal abstraction |
| // for an internal buffer. |
| // get == input == read |
| // put == output == write |
| char_type* _M_in_beg; // Start of get area. |
| char_type* _M_in_cur; // Current read area. |
| char_type* _M_in_end; // End of get area. |
| char_type* _M_out_beg; // Start of put area. |
| char_type* _M_out_cur; // Current put area. |
| char_type* _M_out_end; // End of put area. |
| |
| // Place to stash in || out || in | out settings for current streambuf. |
| ios_base::openmode _M_mode; |
| |
| // Current locale setting. |
| locale _M_buf_locale; |
| |
| // True iff locale is initialized. |
| bool _M_buf_locale_init; |
| |
| // Necessary bits for putback buffer management. Only used in |
| // the basic_filebuf class, as necessary for the standard |
| // requirements. The only basic_streambuf member function that |
| // needs access to these data members is in_avail... |
| // NB: pbacks of over one character are not currently supported. |
| int_type _M_pback_size; |
| char_type* _M_pback; |
| char_type* _M_pback_cur_save; |
| char_type* _M_pback_end_save; |
| bool _M_pback_init; |
| |
| // Initializes pback buffers, and moves normal buffers to safety. |
| // Assumptions: |
| // _M_in_cur has already been moved back |
| void |
| _M_pback_create() |
| { |
| if (!_M_pback_init) |
| { |
| int_type __dist = _M_in_end - _M_in_cur; |
| int_type __len = min(_M_pback_size, __dist); |
| traits_type::copy(_M_pback, _M_in_cur, __len); |
| _M_pback_cur_save = _M_in_cur; |
| _M_pback_end_save = _M_in_end; |
| this->setg(_M_pback, _M_pback, _M_pback + __len); |
| _M_pback_init = true; |
| } |
| } |
| |
| // Deactivates pback buffer contents, and restores normal buffer. |
| // Assumptions: |
| // The pback buffer has only moved forward. |
| void |
| _M_pback_destroy() |
| { |
| if (_M_pback_init) |
| { |
| // Length _M_in_cur moved in the pback buffer. |
| int_type __off_cur = _M_in_cur - _M_pback; |
| |
| // For in | out buffers, the end can be pushed back... |
| int_type __off_end = 0; |
| int_type __pback_len = _M_in_end - _M_pback; |
| int_type __save_len = _M_pback_end_save - _M_buf; |
| if (__pback_len > __save_len) |
| __off_end = __pback_len - __save_len; |
| |
| this->setg(_M_buf, _M_pback_cur_save + __off_cur, |
| _M_pback_end_save + __off_end); |
| _M_pback_cur_save = NULL; |
| _M_pback_end_save = NULL; |
| _M_pback_init = false; |
| } |
| } |
| |
| // Correctly sets the _M_in_cur pointer, and bumps the |
| // _M_out_cur pointer as well if necessary. |
| void |
| _M_in_cur_move(off_type __n) // argument needs to be +- |
| { |
| bool __testout = _M_out_cur; |
| _M_in_cur += __n; |
| if (__testout && _M_buf_unified) |
| _M_out_cur += __n; |
| } |
| |
| // Correctly sets the _M_out_cur pointer, and bumps the |
| // appropriate _M_*_end pointers as well. Necessary for the |
| // un-tied stringbufs, in in|out mode. |
| // Invariant: |
| // __n + _M_out_[cur, end] <= _M_buf + _M_buf_size |
| // Assuming all _M_*_[beg, cur, end] pointers are operating on |
| // the same range: |
| // _M_buf <= _M_*_ <= _M_buf + _M_buf_size |
| void |
| _M_out_cur_move(off_type __n) // argument needs to be +- |
| { |
| bool __testin = _M_in_cur; |
| |
| _M_out_cur += __n; |
| if (__testin && _M_buf_unified) |
| _M_in_cur += __n; |
| if (_M_out_cur > _M_out_end) |
| { |
| _M_out_end = _M_out_cur; |
| // NB: in | out buffers drag the _M_in_end pointer along... |
| if (__testin) |
| _M_in_end += __n; |
| } |
| } |
| |
| // Return the size of the output buffer. This depends on the |
| // buffer in use: allocated buffers have a stored size in |
| // _M_buf_size and setbuf() buffers don't. |
| off_type |
| _M_out_buf_size() |
| { |
| off_type __ret = 0; |
| if (_M_out_cur) |
| { |
| // Using allocated buffer. |
| if (_M_out_beg == _M_buf) |
| __ret = _M_out_beg + _M_buf_size - _M_out_cur; |
| // Using non-allocated buffer. |
| else |
| __ret = _M_out_end - _M_out_cur; |
| } |
| return __ret; |
| } |
| |
| // These three functions are used to clarify internal buffer |
| // maintenance. After an overflow, or after a seekoff call that |
| // started at beg or end, or possibly when the stream becomes |
| // unbuffered, and a myrid other obscure corner cases, the |
| // internal buffer does not truly reflect the contents of the |
| // external buffer. At this point, for whatever reason, it is in |
| // an indeterminate state. |
| void |
| _M_set_indeterminate(void) |
| { |
| if (_M_mode & ios_base::in) |
| this->setg(_M_buf, _M_buf, _M_buf); |
| if (_M_mode & ios_base::out) |
| this->setp(_M_buf, _M_buf); |
| } |
| |
| void |
| _M_set_determinate(off_type __off) |
| { |
| bool __testin = _M_mode & ios_base::in; |
| bool __testout = _M_mode & ios_base::out; |
| if (__testin) |
| this->setg(_M_buf, _M_buf, _M_buf + __off); |
| if (__testout) |
| this->setp(_M_buf, _M_buf + __off); |
| } |
| |
| bool |
| _M_is_indeterminate(void) |
| { |
| bool __ret = false; |
| // Don't return true if unbuffered. |
| if (_M_buf) |
| { |
| if (_M_mode & ios_base::in) |
| __ret = _M_in_beg == _M_in_cur && _M_in_cur == _M_in_end; |
| if (_M_mode & ios_base::out) |
| __ret = _M_out_beg == _M_out_cur && _M_out_cur == _M_out_end; |
| } |
| return __ret; |
| } |
| |
| public: |
| virtual |
| ~basic_streambuf() |
| { |
| _M_buf_unified = false; |
| _M_buf_size = 0; |
| _M_buf_size_opt = 0; |
| _M_mode = ios_base::openmode(0); |
| _M_buf_locale_init = false; |
| } |
| |
| // Locales: |
| locale |
| pubimbue(const locale &__loc) |
| { |
| locale __tmp(this->getloc()); |
| this->imbue(__loc); |
| return __tmp; |
| } |
| |
| locale |
| getloc() const |
| { |
| if (_M_buf_locale_init) |
| return _M_buf_locale; |
| else |
| return locale(); |
| } |
| |
| // Buffer and positioning: |
| __streambuf_type* |
| pubsetbuf(char_type* __s, streamsize __n) |
| { return this->setbuf(__s, __n); } |
| |
| pos_type |
| pubseekoff(off_type __off, ios_base::seekdir __way, |
| ios_base::openmode __mode = ios_base::in | ios_base::out) |
| { return this->seekoff(__off, __way, __mode); } |
| |
| pos_type |
| pubseekpos(pos_type __sp, |
| ios_base::openmode __mode = ios_base::in | ios_base::out) |
| { return this->seekpos(__sp, __mode); } |
| |
| int |
| pubsync() { return this->sync(); } |
| |
| // Get and put areas: |
| // Get area: |
| streamsize |
| in_avail() |
| { |
| streamsize __ret; |
| if (_M_in_cur && _M_in_cur < _M_in_end) |
| { |
| if (_M_pback_init) |
| { |
| int_type __save_len = _M_pback_end_save - _M_pback_cur_save; |
| int_type __pback_len = _M_in_cur - _M_pback; |
| __ret = __save_len - __pback_len; |
| } |
| else |
| __ret = this->egptr() - this->gptr(); |
| } |
| else |
| __ret = this->showmanyc(); |
| return __ret; |
| } |
| |
| int_type |
| snextc() |
| { |
| int_type __eof = traits_type::eof(); |
| return (this->sbumpc() == __eof ? __eof : this->sgetc()); |
| } |
| |
| int_type |
| sbumpc(); |
| |
| int_type |
| sgetc() |
| { |
| int_type __ret; |
| if (_M_in_cur && _M_in_cur < _M_in_end) |
| __ret = traits_type::to_int_type(*(this->gptr())); |
| else |
| __ret = this->underflow(); |
| return __ret; |
| } |
| |
| streamsize |
| sgetn(char_type* __s, streamsize __n) |
| { return this->xsgetn(__s, __n); } |
| |
| // Putback: |
| int_type |
| sputbackc(char_type __c); |
| |
| int_type |
| sungetc(); |
| |
| // Put area: |
| int_type |
| sputc(char_type __c); |
| |
| streamsize |
| sputn(const char_type* __s, streamsize __n) |
| { return this->xsputn(__s, __n); } |
| |
| protected: |
| basic_streambuf() |
| : _M_buf(NULL), _M_buf_size(0), |
| _M_buf_size_opt(static_cast<int_type>(BUFSIZ)), _M_buf_unified(false), |
| _M_in_beg(0), _M_in_cur(0), _M_in_end(0), _M_out_beg(0), _M_out_cur(0), |
| _M_out_end(0), _M_mode(ios_base::openmode(0)), _M_buf_locale(locale()), |
| _M_buf_locale_init(false), _M_pback_size(1), _M_pback(NULL), |
| _M_pback_cur_save(NULL), _M_pback_end_save(NULL), _M_pback_init(false) |
| { } |
| |
| // Get area: |
| char_type* |
| eback() const { return _M_in_beg; } |
| |
| char_type* |
| gptr() const { return _M_in_cur; } |
| |
| char_type* |
| egptr() const { return _M_in_end; } |
| |
| void |
| gbump(int __n) { _M_in_cur += __n; } |
| |
| void |
| setg(char_type* __gbeg, char_type* __gnext, char_type* __gend) |
| { |
| _M_in_beg = __gbeg; |
| _M_in_cur = __gnext; |
| _M_in_end = __gend; |
| if (!(_M_mode & ios_base::in) && __gbeg && __gnext && __gend) |
| _M_mode = _M_mode | ios_base::in; |
| } |
| |
| // Put area: |
| char_type* |
| pbase() const { return _M_out_beg; } |
| |
| char_type* |
| pptr() const { return _M_out_cur; } |
| |
| char_type* |
| epptr() const { return _M_out_end; } |
| |
| void |
| pbump(int __n) { _M_out_cur += __n; } |
| |
| void |
| setp(char_type* __pbeg, char_type* __pend) |
| { |
| _M_out_beg = _M_out_cur = __pbeg; |
| _M_out_end = __pend; |
| if (!(_M_mode & ios_base::out) && __pbeg && __pend) |
| _M_mode = _M_mode | ios_base::out; |
| } |
| |
| // Virtual functions: |
| // Locales: |
| virtual void |
| imbue(const locale& __loc) |
| { |
| _M_buf_locale_init = true; |
| if (_M_buf_locale != __loc) |
| _M_buf_locale = __loc; |
| } |
| |
| // Buffer management and positioning: |
| virtual basic_streambuf<char_type,_Traits>* |
| setbuf(char_type*, streamsize) |
| { return this; } |
| |
| virtual pos_type |
| seekoff(off_type, ios_base::seekdir, |
| ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out) |
| { return pos_type(off_type(-1)); } |
| |
| virtual pos_type |
| seekpos(pos_type, |
| ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out) |
| { return pos_type(off_type(-1)); } |
| |
| virtual int |
| sync() { return 0; } |
| |
| // Get area: |
| virtual streamsize |
| showmanyc() { return 0; } |
| |
| virtual streamsize |
| xsgetn(char_type* __s, streamsize __n); |
| |
| virtual int_type |
| underflow() |
| { return traits_type::eof(); } |
| |
| virtual int_type |
| uflow() |
| { |
| int_type __ret = traits_type::eof(); |
| bool __testeof = this->underflow() == __ret; |
| bool __testpending = _M_in_cur && _M_in_cur < _M_in_end; |
| if (!__testeof && __testpending) |
| { |
| __ret = traits_type::to_int_type(*_M_in_cur); |
| ++_M_in_cur; |
| if (_M_buf_unified && _M_mode & ios_base::out) |
| ++_M_out_cur; |
| } |
| return __ret; |
| } |
| |
| // Putback: |
| virtual int_type |
| pbackfail(int_type /* __c */ = traits_type::eof()) |
| { return traits_type::eof(); } |
| |
| // Put area: |
| virtual streamsize |
| xsputn(const char_type* __s, streamsize __n); |
| |
| virtual int_type |
| overflow(int_type /* __c */ = traits_type::eof()) |
| { return traits_type::eof(); } |
| |
| #ifdef _GLIBCPP_DEPRECATED |
| public: |
| void |
| stossc() |
| { |
| if (_M_in_cur < _M_in_end) |
| ++_M_in_cur; |
| else |
| this->uflow(); |
| } |
| #endif |
| |
| #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS |
| private: |
| basic_streambuf(const __streambuf_type&); |
| |
| __streambuf_type& |
| operator=(const __streambuf_type&); |
| #endif |
| }; |
| |
| } // namespace std |
| |
| #ifdef _GLIBCPP_NO_TEMPLATE_EXPORT |
| # define export |
| #ifdef _GLIBCPP_FULLY_COMPLIANT_HEADERS |
| #include <bits/streambuf.tcc> |
| #endif |
| #endif |
| |
| #endif /* _CPP_STREAMBUF */ |
| |