// File based streams -*- C++ -*- // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003 // 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: 27.8 File-based streams // /** @file fstream * This is a Standard C++ Library header. You should @c #include this header * in your programs, rather than any of the "st[dl]_*.h" implementation files. */ #ifndef _CPP_FSTREAM #define _CPP_FSTREAM 1 #pragma GCC system_header #include #include #include // For codecvt #include #include namespace std { template class basic_filebuf : public basic_streambuf<_CharT, _Traits> { 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 basic_streambuf __streambuf_type; typedef basic_filebuf __filebuf_type; typedef __basic_file __file_type; typedef typename traits_type::state_type __state_type; typedef codecvt __codecvt_type; typedef typename __codecvt_type::result __res_type; typedef ctype __ctype_type; friend class ios_base; // For sync_with_stdio. protected: // Data Members: // MT lock inherited from libio or other low-level io library. __c_lock _M_lock; // External buffer. __file_type _M_file; // Current and beginning state type for codecvt. __state_type _M_state_cur; __state_type _M_state_beg; // Set iff _M_buf is allocated memory from _M_allocate_internal_buffer. bool _M_buf_allocated; // XXX Needed? bool _M_last_overflowed; // The position in the buffer corresponding to the external file // pointer. char_type* _M_filepos; public: // Constructors/destructor: basic_filebuf(); virtual ~basic_filebuf() { this->close(); _M_last_overflowed = false; } // Members: bool is_open() const { return _M_file.is_open(); } __filebuf_type* open(const char* __s, ios_base::openmode __mode); __filebuf_type* close(); protected: void _M_allocate_internal_buffer(); void _M_destroy_internal_buffer(); // Overridden virtual functions: virtual streamsize showmanyc(); // Stroustrup, 1998, p. 628 // underflow() and uflow() functions are called to get the next // charater from the real input source when the buffer is empty. // Buffered input uses underflow() // The only difference between underflow() and uflow() is that the // latter bumps _M_in_cur after the read. In the sync_with_stdio // case, this is important, as we need to unget the read character in // the underflow() case in order to maintain synchronization. So // instead of calling underflow() from uflow(), we create a common // subroutine to do the real work. int_type _M_underflow_common(bool __bump); virtual int_type underflow(); virtual int_type uflow(); virtual int_type pbackfail(int_type __c = _Traits::eof()); // NB: For what the standard expects of the overflow function, // see _M_really_overflow(), below. Because basic_streambuf's // sputc/sputn call overflow directly, and the complications of // this implementation's setting of the initial pointers all // equal to _M_buf when initializing, it seems essential to have // this in actuality be a helper function that checks for the // eccentricities of this implementation, and then call // overflow() if indeed the buffer is full. virtual int_type overflow(int_type __c = _Traits::eof()); // Stroustrup, 1998, p 648 // The overflow() function is called to transfer characters to the // real output destination when the buffer is full. A call to // overflow(c) outputs the contents of the buffer plus the // character c. // 27.5.2.4.5 // Consume some sequence of the characters in the pending sequence. int_type _M_really_overflow(int_type __c = _Traits::eof()); // Convert internal byte sequence to external, char-based // sequence via codecvt. void _M_convert_to_external(char_type*, streamsize, streamsize&, streamsize&); virtual __streambuf_type* setbuf(char_type* __s, streamsize __n); virtual pos_type seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode = ios_base::in | ios_base::out); virtual pos_type seekpos(pos_type __pos, ios_base::openmode __mode = ios_base::in | ios_base::out); virtual int sync() { bool __testput = this->_M_out_cur && this->_M_out_beg < this->_M_out_end; // Make sure that the internal buffer resyncs its idea of // the file position with the external file. if (__testput) { // Need to restore current position after the write. off_type __off = this->_M_out_cur - this->_M_out_end; _M_really_overflow(); // _M_file.sync() will be called within if (__off) _M_file.seekoff(__off, ios_base::cur); } else _M_file.sync(); _M_last_overflowed = false; return 0; } virtual void imbue(const locale& __loc); virtual streamsize xsgetn(char_type* __s, streamsize __n) { streamsize __ret = 0; // Clear out pback buffer before going on to the real deal... if (this->_M_pback_init) { while (__ret < __n && this->_M_in_cur < this->_M_in_end) { *__s = *this->_M_in_cur; ++__ret; ++__s; ++this->_M_in_cur; } this->_M_pback_destroy(); } if (__ret < __n) __ret += __streambuf_type::xsgetn(__s, __n - __ret); return __ret; } virtual streamsize xsputn(const char_type* __s, streamsize __n) { this->_M_pback_destroy(); return __streambuf_type::xsputn(__s, __n); } void _M_output_unshift(); // 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 (this->_M_mode & ios_base::in) this->setg(this->_M_buf, this->_M_buf, this->_M_buf); if (this->_M_mode & ios_base::out) this->setp(this->_M_buf, this->_M_buf); this->_M_filepos = this->_M_buf; } void _M_set_determinate(off_type __off) { bool __testin = this->_M_mode & ios_base::in; bool __testout = this->_M_mode & ios_base::out; if (__testin) this->setg(this->_M_buf, this->_M_buf, this->_M_buf + __off); if (__testout) this->setp(this->_M_buf, this->_M_buf + __off); this->_M_filepos = this->_M_buf + __off; } bool _M_is_indeterminate(void) { bool __ret = false; // Don't return true if unbuffered. if (this->_M_buf) { if (this->_M_mode & ios_base::in) __ret = this->_M_in_beg == this->_M_in_cur && this->_M_in_cur == this->_M_in_end; if (this->_M_mode & ios_base::out) __ret = this->_M_out_beg == this->_M_out_cur && this->_M_out_cur == this->_M_out_end; } return __ret; } }; // Explicit specializations. template<> basic_filebuf::int_type basic_filebuf::_M_underflow_common(bool __bump); #ifdef _GLIBCPP_USE_WCHAR_T template<> basic_filebuf::int_type basic_filebuf::_M_underflow_common(bool __bump); #endif // Generic definitions. template typename basic_filebuf<_CharT, _Traits>::int_type basic_filebuf<_CharT, _Traits>::underflow() { return _M_underflow_common(false); } template typename basic_filebuf<_CharT, _Traits>::int_type basic_filebuf<_CharT, _Traits>::uflow() { return _M_underflow_common(true); } // 27.8.1.5 Template class basic_ifstream /** * Derivation of general input streams, specific to files. */ template class basic_ifstream : public basic_istream<_CharT, _Traits> { 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 basic_filebuf __filebuf_type; typedef basic_istream __istream_type; private: __filebuf_type _M_filebuf; public: // Constructors/Destructors: /** Default constructor. Create an input file stream. */ basic_ifstream() : __istream_type(NULL), _M_filebuf() { this->init(&_M_filebuf); } /** * @brief Create an input file stream. * @param s Null terminated string specifying filename. * @param mode Open file in specified mode (see std::ios_base). * * Tip: When using std::string to hold the filename, you must use * .c_str() before passing it to this constructor. */ explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in) : __istream_type(NULL), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } ~basic_ifstream() { } // Members: /** * @brief Get a pointer to the file stream's buffer. * @return Pointer to basic_filebuf. */ __filebuf_type* rdbuf() const { return const_cast<__filebuf_type*>(&_M_filebuf); } bool is_open() { return _M_filebuf.is_open(); } void open(const char* __s, ios_base::openmode __mode = ios_base::in) { if (!_M_filebuf.open(__s, __mode | ios_base::in)) this->setstate(ios_base::failbit); } /** Close the file. */ void close() { if (!_M_filebuf.close()) this->setstate(ios_base::failbit); } }; // 27.8.1.8 Template class basic_ofstream /** * Derivation of general output streams, specific to files. */ template class basic_ofstream : public basic_ostream<_CharT,_Traits> { 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 basic_filebuf __filebuf_type; typedef basic_ostream __ostream_type; private: __filebuf_type _M_filebuf; public: // Constructors: /** Default constructor for output file_stream. */ basic_ofstream() : __ostream_type(NULL), _M_filebuf() { this->init(&_M_filebuf); } /** * @brief Create an output stream. * @param s Null terminated string specifying filename. * @param mode Open file in specified mode (see std::ios_base). * * Tip: When using std::string to hold the filename, you must use * .c_str() before passing it to this constructor. */ explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out|ios_base::trunc) : __ostream_type(NULL), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } ~basic_ofstream() { } // Members: /** * @brief Get a pointer to the file stream's buffer. * @return Pointer to basic_filebuf. */ __filebuf_type* rdbuf() const { return const_cast<__filebuf_type*>(&_M_filebuf); } /** * @brief Query to see if file stream is open. * @return True if stream is open. */ bool is_open() { return _M_filebuf.is_open(); } /** * @brief Specify a file to open for output. * @param s Null terminated string specifying filename. * @param mode Mode in which to open file (see std::ios_base). * * Tip: When using std::string to hold the filename, you must use * .c_str() before passing it to this constructor. */ void open(const char* __s, ios_base::openmode __mode = ios_base::out | ios_base::trunc) { if (!_M_filebuf.open(__s, __mode | ios_base::out)) this->setstate(ios_base::failbit); } /** Close the file stream. */ void close() { if (!_M_filebuf.close()) this->setstate(ios_base::failbit); } }; // 27.8.1.11 Template class basic_fstream /** * Derivation of general input/output streams, specific to files. */ template class basic_fstream : public basic_iostream<_CharT, _Traits> { 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 basic_filebuf __filebuf_type; typedef basic_ios __ios_type; typedef basic_iostream __iostream_type; private: __filebuf_type _M_filebuf; public: // Constructors/destructor: /** Default constructor. Create a file stream. */ basic_fstream() : __iostream_type(NULL), _M_filebuf() { this->init(&_M_filebuf); } /** * @brief Create an input/output stream. * @param s Null terminated string specifying filename. * @param mode Open file in specified mode (see std::ios_base). * * Tip: When using std::string to hold the filename, you must use * .c_str() before passing it to this constructor. */ explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out) : __iostream_type(NULL), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } ~basic_fstream() { } // Members: /** * @brief Get a pointer to the file stream's buffer. * @return Pointer to basic_filebuf. */ __filebuf_type* rdbuf() const { return const_cast<__filebuf_type*>(&_M_filebuf); } /** * @brief Query to see if file stream is open. * @return True if stream is open. */ bool is_open() { return _M_filebuf.is_open(); } /** * @brief Specify a file to open for input and/or output. * @param s Null terminated string specifying filename. * @param mode Mode in which to open file (see std::ios_base). * * Tip: When using std::string to hold the filename, you must use * .c_str() before passing it to this constructor. */ void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out) { if (!_M_filebuf.open(__s, __mode)) this->setstate(ios_base::failbit); } /** Close the file stream. */ void close() { if (!_M_filebuf.close()) this->setstate(ios_base::failbit); } }; } // namespace std #ifdef _GLIBCPP_NO_TEMPLATE_EXPORT # define export #endif #ifdef _GLIBCPP_FULLY_COMPLIANT_HEADERS # include #endif #endif