1 // wstring_convert implementation -*- C++ -*-
3 // Copyright (C) 2015 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file bits/locale_conv.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{locale}
30 #ifndef _LOCALE_CONV_H
31 #define _LOCALE_CONV_H 1
33 #if __cplusplus < 201103L
34 # include <bits/c++0x_warning.h>
38 #include "stringfwd.h"
39 #include "allocator.h"
41 #include "unique_ptr.h"
43 namespace std _GLIBCXX_VISIBILITY(default)
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
47 #ifdef _GLIBCXX_USE_WCHAR_T
54 _GLIBCXX_BEGIN_NAMESPACE_CXX11
55 /// String conversions
56 template<typename _Codecvt, typename _Elem = wchar_t,
57 typename _Wide_alloc = allocator<_Elem>,
58 typename _Byte_alloc = allocator<char>>
62 typedef basic_string<char, char_traits<char>, _Byte_alloc> byte_string;
63 typedef basic_string<_Elem, char_traits<_Elem>, _Wide_alloc> wide_string;
64 typedef typename _Codecvt::state_type state_type;
65 typedef typename wide_string::traits_type::int_type int_type;
67 /** Default constructor.
69 * @param __pcvt The facet to use for conversions.
71 * Takes ownership of @p __pcvt and will delete it in the destructor.
74 wstring_convert(_Codecvt* __pcvt = new _Codecvt()) : _M_cvt(__pcvt)
77 __throw_logic_error("wstring_convert");
80 /** Construct with an initial converstion state.
82 * @param __pcvt The facet to use for conversions.
83 * @param __state Initial conversion state.
85 * Takes ownership of @p __pcvt and will delete it in the destructor.
86 * The object's conversion state will persist between conversions.
88 wstring_convert(_Codecvt* __pcvt, state_type __state)
89 : _M_cvt(__pcvt), _M_state(__state), _M_with_cvtstate(true)
92 __throw_logic_error("wstring_convert");
95 /** Construct with error strings.
97 * @param __byte_err A string to return on failed conversions.
98 * @param __wide_err A wide string to return on failed conversions.
101 wstring_convert(const byte_string& __byte_err,
102 const wide_string& __wide_err = wide_string())
103 : _M_cvt(new _Codecvt),
104 _M_byte_err_string(__byte_err), _M_wide_err_string(__wide_err),
105 _M_with_strings(true)
108 __throw_logic_error("wstring_convert");
111 ~wstring_convert() = default;
113 // _GLIBCXX_RESOLVE_LIB_DEFECTS
114 // 2176. Special members for wstring_convert and wbuffer_convert
115 wstring_convert(const wstring_convert&) = delete;
116 wstring_convert& operator=(const wstring_convert&) = delete;
118 /// @{ Convert from bytes.
120 from_bytes(char __byte)
122 char __bytes[2] = { __byte };
123 return from_bytes(__bytes, __bytes+1);
127 from_bytes(const char* __ptr)
128 { return from_bytes(__ptr, __ptr+char_traits<char>::length(__ptr)); }
131 from_bytes(const byte_string& __str)
133 auto __ptr = __str.data();
134 return from_bytes(__ptr, __ptr + __str.size());
138 from_bytes(const char* __first, const char* __last)
140 auto __errstr = _M_with_strings ? &_M_wide_err_string : nullptr;
141 _ConvFn<char, _Elem> __fn = &_Codecvt::in;
142 return _M_conv(__first, __last, __errstr, __fn);
146 /// @{ Convert to bytes.
148 to_bytes(_Elem __wchar)
150 _Elem __wchars[2] = { __wchar };
151 return to_bytes(__wchars, __wchars+1);
155 to_bytes(const _Elem* __ptr)
157 return to_bytes(__ptr, __ptr+wide_string::traits_type::length(__ptr));
161 to_bytes(const wide_string& __wstr)
163 auto __ptr = __wstr.data();
164 return to_bytes(__ptr, __ptr + __wstr.size());
168 to_bytes(const _Elem* __first, const _Elem* __last)
170 auto __errstr = _M_with_strings ? &_M_byte_err_string : nullptr;
171 _ConvFn<_Elem, char> __fn = &_Codecvt::out;
172 return _M_conv(__first, __last, __errstr, __fn);
176 // _GLIBCXX_RESOLVE_LIB_DEFECTS
177 // 2174. wstring_convert::converted() should be noexcept
178 /// The number of elements successfully converted in the last conversion.
179 size_t converted() const noexcept { return _M_count; }
181 /// The final conversion state of the last conversion.
182 state_type state() const { return _M_state; }
185 template<typename _InC, typename _OutC>
187 = codecvt_base::result
188 (_Codecvt::*)(state_type&, const _InC*, const _InC*, const _InC*&,
189 _OutC*, _OutC*, _OutC*&) const;
191 template<typename _InChar, typename _OutStr, typename _MemFn>
193 _M_conv(const _InChar* __first, const _InChar* __last,
194 const _OutStr* __err, _MemFn __memfn)
196 auto __outstr = __err ? _OutStr(__err->get_allocator()) : _OutStr();
198 if (__first == __last)
204 if (!_M_with_cvtstate)
205 _M_state = state_type();
207 size_t __outchars = 0;
208 auto __next = __first;
209 const auto __maxlen = _M_cvt->max_length() + 1;
211 codecvt_base::result __result;
214 __outstr.resize(__outstr.size() + (__last - __next) * __maxlen);
215 auto __outnext = &__outstr.front() + __outchars;
216 auto const __outlast = &__outstr.back() + 1;
217 __result = ((*_M_cvt).*__memfn)(_M_state, __next, __last, __next,
218 __outnext, __outlast, __outnext);
219 __outchars = __outnext - &__outstr.front();
221 while (__result == codecvt_base::partial && __next != __last
222 && (__outstr.size() - __outchars) < __maxlen);
224 if (__result == codecvt_base::noconv)
226 __outstr.assign(__first, __last);
227 _M_count = __outstr.size();
231 __outstr.resize(__outchars);
232 _M_count = __next - __first;
234 if (__result != codecvt_base::error)
239 __throw_range_error("wstring_convert");
242 unique_ptr<_Codecvt> _M_cvt;
243 byte_string _M_byte_err_string;
244 wide_string _M_wide_err_string;
245 state_type _M_state = state_type();
247 bool _M_with_cvtstate = false;
248 bool _M_with_strings = false;
250 _GLIBCXX_END_NAMESPACE_CXX11
252 /// Buffer conversions
253 template<typename _Codecvt, typename _Elem = wchar_t,
254 typename _Tr = char_traits<_Elem>>
255 class wbuffer_convert : public basic_streambuf<_Elem, _Tr>
257 typedef basic_streambuf<_Elem, _Tr> _Wide_streambuf;
260 typedef typename _Codecvt::state_type state_type;
262 /** Default constructor.
264 * @param __bytebuf The underlying byte stream buffer.
265 * @param __pcvt The facet to use for conversions.
266 * @param __state Initial conversion state.
268 * Takes ownership of @p __pcvt and will delete it in the destructor.
271 wbuffer_convert(streambuf* __bytebuf = 0, _Codecvt* __pcvt = new _Codecvt,
272 state_type __state = state_type())
273 : _M_buf(__bytebuf), _M_cvt(__pcvt), _M_state(__state)
276 __throw_logic_error("wbuffer_convert");
278 _M_always_noconv = _M_cvt->always_noconv();
282 this->setp(_M_put_area, _M_put_area + _S_buffer_length);
283 this->setg(_M_get_area + _S_putback_length,
284 _M_get_area + _S_putback_length,
285 _M_get_area + _S_putback_length);
289 ~wbuffer_convert() = default;
291 // _GLIBCXX_RESOLVE_LIB_DEFECTS
292 // 2176. Special members for wstring_convert and wbuffer_convert
293 wbuffer_convert(const wbuffer_convert&) = delete;
294 wbuffer_convert& operator=(const wbuffer_convert&) = delete;
296 streambuf* rdbuf() const noexcept { return _M_buf; }
299 rdbuf(streambuf *__bytebuf) noexcept
301 auto __prev = _M_buf;
306 /// The conversion state following the last conversion.
307 state_type state() const noexcept { return _M_state; }
312 { return _M_buf && _M_conv_put() && _M_buf->pubsync() ? 0 : -1; }
314 typename _Wide_streambuf::int_type
315 overflow(typename _Wide_streambuf::int_type __out)
317 if (!_M_buf || !_M_conv_put())
319 else if (!_Tr::eq_int_type(__out, _Tr::eof()))
320 return this->sputc(__out);
321 return _Tr::not_eof(__out);
324 typename _Wide_streambuf::int_type
330 if (this->gptr() < this->egptr() || (_M_buf && _M_conv_get()))
331 return _Tr::to_int_type(*this->gptr());
337 xsputn(const typename _Wide_streambuf::char_type* __s, streamsize __n)
339 if (!_M_buf || __n == 0)
341 streamsize __done = 0;
344 auto __nn = std::min<streamsize>(this->epptr() - this->pptr(),
346 _Tr::copy(this->pptr(), __s + __done, __nn);
349 } while (__done < __n && _M_conv_put());
354 // fill the get area from converted contents of the byte stream buffer
358 const streamsize __pb1 = this->gptr() - this->eback();
359 const streamsize __pb2 = _S_putback_length;
360 const streamsize __npb = std::min(__pb1, __pb2);
362 _Tr::move(_M_get_area + _S_putback_length - __npb,
363 this->gptr() - __npb, __npb);
365 streamsize __nbytes = sizeof(_M_get_buf) - _M_unconv;
366 __nbytes = std::min(__nbytes, _M_buf->in_avail());
369 __nbytes = _M_buf->sgetn(_M_get_buf + _M_unconv, __nbytes);
372 __nbytes += _M_unconv;
374 // convert _M_get_buf into _M_get_area
376 _Elem* __outbuf = _M_get_area + _S_putback_length;
377 _Elem* __outnext = __outbuf;
378 const char* __bnext = _M_get_buf;
380 codecvt_base::result __result;
381 if (_M_always_noconv)
382 __result = codecvt_base::noconv;
385 _Elem* __outend = _M_get_area + _S_buffer_length;
387 __result = _M_cvt->in(_M_state,
388 __bnext, __bnext + __nbytes, __bnext,
389 __outbuf, __outend, __outnext);
392 if (__result == codecvt_base::noconv)
394 // cast is safe because noconv means _Elem is same type as char
395 auto __get_buf = reinterpret_cast<const _Elem*>(_M_get_buf);
396 _Tr::copy(__outbuf, __get_buf, __nbytes);
401 if ((_M_unconv = _M_get_buf + __nbytes - __bnext))
402 char_traits<char>::move(_M_get_buf, __bnext, _M_unconv);
404 this->setg(__outbuf, __outbuf, __outnext);
406 return __result != codecvt_base::error;
415 _M_put(const char* __p, streamsize __n)
417 if (_M_buf->sputn(__p, __n) < __n)
421 // convert the put area and write to the byte stream buffer
425 _Elem* const __first = this->pbase();
426 const _Elem* const __last = this->pptr();
427 const streamsize __pending = __last - __first;
429 if (_M_always_noconv)
430 return _M_put(__first, __pending);
432 char __outbuf[2 * _S_buffer_length];
434 const _Elem* __next = __first;
435 const _Elem* __start;
439 char* __outnext = __outbuf;
440 char* const __outlast = __outbuf + sizeof(__outbuf);
441 auto __result = _M_cvt->out(_M_state, __next, __last, __next,
442 __outnext, __outlast, __outnext);
443 if (__result == codecvt_base::error)
445 else if (__result == codecvt_base::noconv)
446 return _M_put(__next, __pending);
448 if (!_M_put(__outbuf, __outnext - __outbuf))
451 while (__next != __last && __next != __start);
453 if (__next != __last)
454 _Tr::move(__first, __next, __last - __next);
456 this->pbump(__first - __next);
457 return __next != __first;
461 unique_ptr<_Codecvt> _M_cvt;
464 static const streamsize _S_buffer_length = 32;
465 static const streamsize _S_putback_length = 3;
466 _Elem _M_put_area[_S_buffer_length];
467 _Elem _M_get_area[_S_buffer_length];
468 streamsize _M_unconv = 0;
469 char _M_get_buf[_S_buffer_length-_S_putback_length];
470 bool _M_always_noconv;
475 #endif // _GLIBCXX_USE_WCHAR_T
477 _GLIBCXX_END_NAMESPACE_VERSION
480 #endif // __cplusplus
482 #endif /* _LOCALE_CONV_H */