1 // Stream buffer classes -*- C++ -*-
2 
3 // Copyright (C) 1997-2022 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file bits/streambuf.tcc
26  *  This is an internal header file, included by other library headers.
27  *  Do not attempt to use it directly. @headername{streambuf}
28  */
29 
30 //
31 // ISO C++ 14882: 27.5  Stream buffers
32 //
33 
34 #ifndef _STREAMBUF_TCC
35 #define _STREAMBUF_TCC 1
36 
37 #pragma GCC system_header
38 
39 namespace std _GLIBCXX_VISIBILITY(default)
40 {
41 _GLIBCXX_BEGIN_NAMESPACE_VERSION
42 
43   template<typename _CharT, typename _Traits>
44     streamsize
45     basic_streambuf<_CharT, _Traits>::
xsgetn(char_type * __s,streamsize __n)46     xsgetn(char_type* __s, streamsize __n)
47     {
48       streamsize __ret = 0;
49       while (__ret < __n)
50           {
51             const streamsize __buf_len = this->egptr() - this->gptr();
52             if (__buf_len)
53               {
54                 const streamsize __remaining = __n - __ret;
55                 const streamsize __len = std::min(__buf_len, __remaining);
56                 traits_type::copy(__s, this->gptr(), __len);
57                 __ret += __len;
58                 __s += __len;
59                 this->__safe_gbump(__len);
60               }
61 
62             if (__ret < __n)
63               {
64                 const int_type __c = this->uflow();
65                 if (!traits_type::eq_int_type(__c, traits_type::eof()))
66                     {
67                       traits_type::assign(*__s++, traits_type::to_char_type(__c));
68                       ++__ret;
69                     }
70                 else
71                     break;
72               }
73           }
74       return __ret;
75     }
76 
77   template<typename _CharT, typename _Traits>
78     streamsize
79     basic_streambuf<_CharT, _Traits>::
xsputn(const char_type * __s,streamsize __n)80     xsputn(const char_type* __s, streamsize __n)
81     {
82       streamsize __ret = 0;
83       while (__ret < __n)
84           {
85             const streamsize __buf_len = this->epptr() - this->pptr();
86             if (__buf_len)
87               {
88                 const streamsize __remaining = __n - __ret;
89                 const streamsize __len = std::min(__buf_len, __remaining);
90                 traits_type::copy(this->pptr(), __s, __len);
91                 __ret += __len;
92                 __s += __len;
93                 this->__safe_pbump(__len);
94               }
95 
96             if (__ret < __n)
97               {
98                 int_type __c = this->overflow(traits_type::to_int_type(*__s));
99                 if (!traits_type::eq_int_type(__c, traits_type::eof()))
100                     {
101                       ++__ret;
102                       ++__s;
103                     }
104                 else
105                     break;
106               }
107           }
108       return __ret;
109     }
110 
111   // Conceivably, this could be used to implement buffer-to-buffer
112   // copies, if this was ever desired in an un-ambiguous way by the
113   // standard.
114   template<typename _CharT, typename _Traits>
115     streamsize
__copy_streambufs_eof(basic_streambuf<_CharT,_Traits> * __sbin,basic_streambuf<_CharT,_Traits> * __sbout,bool & __ineof)116     __copy_streambufs_eof(basic_streambuf<_CharT, _Traits>* __sbin,
117                                 basic_streambuf<_CharT, _Traits>* __sbout,
118                                 bool& __ineof)
119     {
120       streamsize __ret = 0;
121       __ineof = true;
122       typename _Traits::int_type __c = __sbin->sgetc();
123       while (!_Traits::eq_int_type(__c, _Traits::eof()))
124           {
125             __c = __sbout->sputc(_Traits::to_char_type(__c));
126             if (_Traits::eq_int_type(__c, _Traits::eof()))
127               {
128                 __ineof = false;
129                 break;
130               }
131             ++__ret;
132             __c = __sbin->snextc();
133           }
134       return __ret;
135     }
136 
137   template<typename _CharT, typename _Traits>
138     inline streamsize
__copy_streambufs(basic_streambuf<_CharT,_Traits> * __sbin,basic_streambuf<_CharT,_Traits> * __sbout)139     __copy_streambufs(basic_streambuf<_CharT, _Traits>* __sbin,
140                           basic_streambuf<_CharT, _Traits>* __sbout)
141     {
142       bool __ineof;
143       return __copy_streambufs_eof(__sbin, __sbout, __ineof);
144     }
145 
146   // Inhibit implicit instantiations for required instantiations,
147   // which are defined via explicit instantiations elsewhere.
148 #if _GLIBCXX_EXTERN_TEMPLATE
149   extern template class basic_streambuf<char>;
150 
151   extern template
152     streamsize
153     __copy_streambufs(basic_streambuf<char>*,
154                           basic_streambuf<char>*);
155 
156 #ifdef _GLIBCXX_USE_WCHAR_T
157   extern template class basic_streambuf<wchar_t>;
158 
159   extern template
160     streamsize
161     __copy_streambufs(basic_streambuf<wchar_t>*,
162                           basic_streambuf<wchar_t>*);
163 #endif
164 #endif
165 
166 _GLIBCXX_END_NAMESPACE_VERSION
167 } // namespace std
168 
169 #endif
170