00001 // Temporary buffer implementation -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 2, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // You should have received a copy of the GNU General Public License along 00017 // with this library; see the file COPYING. If not, write to the Free 00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 00019 // USA. 00020 00021 // As a special exception, you may use this file as part of a free software 00022 // library without restriction. Specifically, if other files instantiate 00023 // templates or use macros or inline functions from this file, or you compile 00024 // this file and link it with other files to produce an executable, this 00025 // file does not by itself cause the resulting executable to be covered by 00026 // the GNU General Public License. This exception does not however 00027 // invalidate any other reasons why the executable file might be covered by 00028 // the GNU General Public License. 00029 00030 /* 00031 * 00032 * Copyright (c) 1994 00033 * Hewlett-Packard Company 00034 * 00035 * Permission to use, copy, modify, distribute and sell this software 00036 * and its documentation for any purpose is hereby granted without fee, 00037 * provided that the above copyright notice appear in all copies and 00038 * that both that copyright notice and this permission notice appear 00039 * in supporting documentation. Hewlett-Packard Company makes no 00040 * representations about the suitability of this software for any 00041 * purpose. It is provided "as is" without express or implied warranty. 00042 * 00043 * 00044 * Copyright (c) 1996,1997 00045 * Silicon Graphics Computer Systems, Inc. 00046 * 00047 * Permission to use, copy, modify, distribute and sell this software 00048 * and its documentation for any purpose is hereby granted without fee, 00049 * provided that the above copyright notice appear in all copies and 00050 * that both that copyright notice and this permission notice appear 00051 * in supporting documentation. Silicon Graphics makes no 00052 * representations about the suitability of this software for any 00053 * purpose. It is provided "as is" without express or implied warranty. 00054 */ 00055 00056 /** @file stl_tempbuf.h 00057 * This is an internal header file, included by other library headers. 00058 * You should not attempt to use it directly. 00059 */ 00060 00061 #ifndef __GLIBCPP_INTERNAL_TEMPBUF_H 00062 #define __GLIBCPP_INTERNAL_TEMPBUF_H 00063 00064 namespace std 00065 { 00066 00067 /** 00068 * @if maint 00069 * This class is used in two places: stl_algo.h and ext/memory, where it 00070 * is wrapped as the temporary_buffer class. See temporary_buffer docs for 00071 * more notes. 00072 * @endif 00073 */ 00074 template <class _ForwardIterator, class _Tp> 00075 class _Temporary_buffer 00076 { 00077 // concept requirements 00078 __glibcpp_class_requires(_ForwardIterator, _ForwardIteratorConcept) 00079 00080 ptrdiff_t _M_original_len; 00081 ptrdiff_t _M_len; 00082 _Tp* _M_buffer; 00083 00084 // this is basically get_temporary_buffer() all over again 00085 void _M_allocate_buffer() { 00086 _M_original_len = _M_len; 00087 _M_buffer = 0; 00088 00089 if (_M_len > (ptrdiff_t)(INT_MAX / sizeof(_Tp))) 00090 _M_len = INT_MAX / sizeof(_Tp); 00091 00092 while (_M_len > 0) { 00093 _M_buffer = (_Tp*) malloc(_M_len * sizeof(_Tp)); 00094 if (_M_buffer) 00095 break; 00096 _M_len /= 2; 00097 } 00098 } 00099 00100 void _M_initialize_buffer(const _Tp&, __true_type) {} 00101 void _M_initialize_buffer(const _Tp& val, __false_type) { 00102 uninitialized_fill_n(_M_buffer, _M_len, val); 00103 } 00104 00105 public: 00106 /// As per Table mumble. 00107 ptrdiff_t size() const { return _M_len; } 00108 /// Returns the size requested by the constructor; may be >size(). 00109 ptrdiff_t requested_size() const { return _M_original_len; } 00110 /// As per Table mumble. 00111 _Tp* begin() { return _M_buffer; } 00112 /// As per Table mumble. 00113 _Tp* end() { return _M_buffer + _M_len; } 00114 00115 _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last) { 00116 // Workaround for a __type_traits bug in the pre-7.3 compiler. 00117 typedef typename __type_traits<_Tp>::has_trivial_default_constructor 00118 _Trivial; 00119 00120 try { 00121 _M_len = distance(__first, __last); 00122 _M_allocate_buffer(); 00123 if (_M_len > 0) 00124 _M_initialize_buffer(*__first, _Trivial()); 00125 } 00126 catch(...) 00127 { 00128 free(_M_buffer); 00129 _M_buffer = 0; 00130 _M_len = 0; 00131 __throw_exception_again; 00132 } 00133 } 00134 00135 ~_Temporary_buffer() { 00136 _Destroy(_M_buffer, _M_buffer + _M_len); 00137 free(_M_buffer); 00138 } 00139 00140 private: 00141 // Disable copy constructor and assignment operator. 00142 _Temporary_buffer(const _Temporary_buffer&) {} 00143 void operator=(const _Temporary_buffer&) {} 00144 }; 00145 00146 } // namespace std 00147 00148 #endif /* __GLIBCPP_INTERNAL_TEMPBUF_H */ 00149