1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_STREAMBUF
11#define _LIBCPP_STREAMBUF
12
13/*
14 streambuf synopsis
15
16namespace std
17{
18
19template <class charT, class traits = char_traits<charT> >
20class basic_streambuf
21{
22public:
23 // types:
24 typedef charT char_type;
25 typedef traits traits_type;
26 typedef typename traits_type::int_type int_type;
27 typedef typename traits_type::pos_type pos_type;
28 typedef typename traits_type::off_type off_type;
29
30 virtual ~basic_streambuf();
31
32 // 27.6.2.2.1 locales:
33 locale pubimbue(const locale& loc);
34 locale getloc() const;
35
36 // 27.6.2.2.2 buffer and positioning:
37 basic_streambuf* pubsetbuf(char_type* s, streamsize n);
38 pos_type pubseekoff(off_type off, ios_base::seekdir way,
39 ios_base::openmode which = ios_base::in | ios_base::out);
40 pos_type pubseekpos(pos_type sp,
41 ios_base::openmode which = ios_base::in | ios_base::out);
42 int pubsync();
43
44 // Get and put areas:
45 // 27.6.2.2.3 Get area:
46 streamsize in_avail();
47 int_type snextc();
48 int_type sbumpc();
49 int_type sgetc();
50 streamsize sgetn(char_type* s, streamsize n);
51
52 // 27.6.2.2.4 Putback:
53 int_type sputbackc(char_type c);
54 int_type sungetc();
55
56 // 27.6.2.2.5 Put area:
57 int_type sputc(char_type c);
58 streamsize sputn(const char_type* s, streamsize n);
59
60protected:
61 basic_streambuf();
62 basic_streambuf(const basic_streambuf& rhs);
63 basic_streambuf& operator=(const basic_streambuf& rhs);
64 void swap(basic_streambuf& rhs);
65
66 // 27.6.2.3.2 Get area:
67 char_type* eback() const;
68 char_type* gptr() const;
69 char_type* egptr() const;
70 void gbump(int n);
71 void setg(char_type* gbeg, char_type* gnext, char_type* gend);
72
73 // 27.6.2.3.3 Put area:
74 char_type* pbase() const;
75 char_type* pptr() const;
76 char_type* epptr() const;
77 void pbump(int n);
78 void setp(char_type* pbeg, char_type* pend);
79
80 // 27.6.2.4 virtual functions:
81 // 27.6.2.4.1 Locales:
82 virtual void imbue(const locale& loc);
83
84 // 27.6.2.4.2 Buffer management and positioning:
85 virtual basic_streambuf* setbuf(char_type* s, streamsize n);
86 virtual pos_type seekoff(off_type off, ios_base::seekdir way,
87 ios_base::openmode which = ios_base::in | ios_base::out);
88 virtual pos_type seekpos(pos_type sp,
89 ios_base::openmode which = ios_base::in | ios_base::out);
90 virtual int sync();
91
92 // 27.6.2.4.3 Get area:
93 virtual streamsize showmanyc();
94 virtual streamsize xsgetn(char_type* s, streamsize n);
95 virtual int_type underflow();
96 virtual int_type uflow();
97
98 // 27.6.2.4.4 Putback:
99 virtual int_type pbackfail(int_type c = traits_type::eof());
100
101 // 27.6.2.4.5 Put area:
102 virtual streamsize xsputn(const char_type* s, streamsize n);
103 virtual int_type overflow (int_type c = traits_type::eof());
104};
105
106} // std
107
108*/
109
110#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
111# include <__cxx03/streambuf>
112#else
113# include <__config>
114
115# if _LIBCPP_HAS_LOCALIZATION
116
117# include <__assert>
118# include <__fwd/streambuf.h>
119# include <__locale>
120# include <__memory/valid_range.h>
121# include <__type_traits/is_same.h>
122# include <__utility/scope_guard.h>
123# include <climits>
124# include <ios>
125# include <iosfwd>
126# include <version>
127
128# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
129# pragma GCC system_header
130# endif
131
132_LIBCPP_PUSH_MACROS
133# include <__undef_macros>
134
135_LIBCPP_BEGIN_NAMESPACE_STD
136
137template <class _CharT, class _Traits>
138class basic_streambuf {
139public:
140 // types:
141 typedef _CharT char_type;
142 typedef _Traits traits_type;
143 typedef typename traits_type::int_type int_type;
144 typedef typename traits_type::pos_type pos_type;
145 typedef typename traits_type::off_type off_type;
146
147 static_assert(is_same<_CharT, typename traits_type::char_type>::value,
148 "traits_type::char_type must be the same type as CharT");
149
150 virtual ~basic_streambuf() {}
151
152 // 27.6.2.2.1 locales:
153 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 locale pubimbue(const locale& __loc) {
154 imbue(__loc);
155 locale __r = __loc_;
156 __loc_ = __loc;
157 return __r;
158 }
159
160 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 locale getloc() const { return __loc_; }
161
162 // 27.6.2.2.2 buffer and positioning:
163 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 basic_streambuf* pubsetbuf(char_type* __s, streamsize __n) {
164 return setbuf(__s, __n);
165 }
166
167 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 pos_type
168 pubseekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __which = ios_base::in | ios_base::out) {
169 return seekoff(__off, __way, __which);
170 }
171
172 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 pos_type
173 pubseekpos(pos_type __sp, ios_base::openmode __which = ios_base::in | ios_base::out) {
174 return seekpos(__sp, __which);
175 }
176
177 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 int pubsync() { return sync(); }
178
179 // Get and put areas:
180 // 27.6.2.2.3 Get area:
181 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 streamsize in_avail() {
182 __check_invariants();
183 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
184
185 if (gptr() < egptr())
186 return static_cast<streamsize>(egptr() - gptr());
187 return showmanyc();
188 }
189
190 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 int_type snextc() {
191 __check_invariants();
192 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
193
194 if (sbumpc() == traits_type::eof())
195 return traits_type::eof();
196 return sgetc();
197 }
198
199 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 int_type sbumpc() {
200 __check_invariants();
201 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
202
203 if (gptr() == egptr())
204 return uflow();
205 int_type __c = traits_type::to_int_type(*gptr());
206 this->gbump(1);
207 return __c;
208 }
209
210 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 int_type sgetc() {
211 __check_invariants();
212 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
213
214 if (gptr() == egptr())
215 return underflow();
216 return traits_type::to_int_type(*gptr());
217 }
218
219 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 streamsize sgetn(char_type* __s, streamsize __n) { return xsgetn(__s, __n); }
220
221 // 27.6.2.2.4 Putback:
222 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 int_type sputbackc(char_type __c) {
223 __check_invariants();
224 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
225
226 if (eback() == gptr() || !traits_type::eq(__c, *(gptr() - 1)))
227 return pbackfail(traits_type::to_int_type(__c));
228 this->gbump(-1);
229 return traits_type::to_int_type(*gptr());
230 }
231
232 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 int_type sungetc() {
233 __check_invariants();
234 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
235
236 if (eback() == gptr())
237 return pbackfail();
238 this->gbump(-1);
239 return traits_type::to_int_type(*gptr());
240 }
241
242 // 27.6.2.2.5 Put area:
243 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 int_type sputc(char_type __c) {
244 __check_invariants();
245 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
246
247 if (pptr() == epptr())
248 return overflow(traits_type::to_int_type(__c));
249 *pptr() = __c;
250 this->pbump(1);
251 return traits_type::to_int_type(__c);
252 }
253
254 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 streamsize sputn(const char_type* __s, streamsize __n) {
255 return xsputn(__s, __n);
256 }
257
258protected:
259 basic_streambuf() {}
260 basic_streambuf(const basic_streambuf& __sb)
261 : __loc_(__sb.__loc_),
262 __binp_(__sb.__binp_),
263 __ninp_(__sb.__ninp_),
264 __einp_(__sb.__einp_),
265 __bout_(__sb.__bout_),
266 __nout_(__sb.__nout_),
267 __eout_(__sb.__eout_) {}
268
269 basic_streambuf& operator=(const basic_streambuf& __sb) {
270 __loc_ = __sb.__loc_;
271 __binp_ = __sb.__binp_;
272 __ninp_ = __sb.__ninp_;
273 __einp_ = __sb.__einp_;
274 __bout_ = __sb.__bout_;
275 __nout_ = __sb.__nout_;
276 __eout_ = __sb.__eout_;
277 return *this;
278 }
279
280 void swap(basic_streambuf& __sb) {
281 std::swap(__loc_, __sb.__loc_);
282 std::swap(__binp_, __sb.__binp_);
283 std::swap(__ninp_, __sb.__ninp_);
284 std::swap(__einp_, __sb.__einp_);
285 std::swap(__bout_, __sb.__bout_);
286 std::swap(__nout_, __sb.__nout_);
287 std::swap(__eout_, __sb.__eout_);
288 }
289
290 // 27.6.2.3.2 Get area:
291 _LIBCPP_HIDE_FROM_ABI char_type* eback() const { return __binp_; }
292 _LIBCPP_HIDE_FROM_ABI char_type* gptr() const { return __ninp_; }
293 _LIBCPP_HIDE_FROM_ABI char_type* egptr() const { return __einp_; }
294
295 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 void gbump(int __n) { __ninp_ += __n; }
296
297 // gbump takes an int, so it might not be able to represent the offset we want to add.
298 _LIBCPP_HIDE_FROM_ABI void __gbump_ptrdiff(ptrdiff_t __n) { __ninp_ += __n; }
299
300 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 void setg(char_type* __gbeg, char_type* __gnext, char_type* __gend) {
301 _LIBCPP_ASSERT_VALID_INPUT_RANGE(std::__is_valid_range(__gbeg, __gnext), "[gbeg, gnext) must be a valid range");
302 _LIBCPP_ASSERT_VALID_INPUT_RANGE(std::__is_valid_range(__gbeg, __gend), "[gbeg, gend) must be a valid range");
303 _LIBCPP_ASSERT_VALID_INPUT_RANGE(std::__is_valid_range(__gnext, __gend), "[gnext, gend) must be a valid range");
304 __binp_ = __gbeg;
305 __ninp_ = __gnext;
306 __einp_ = __gend;
307 }
308
309 // 27.6.2.3.3 Put area:
310 _LIBCPP_HIDE_FROM_ABI char_type* pbase() const { return __bout_; }
311 _LIBCPP_HIDE_FROM_ABI char_type* pptr() const { return __nout_; }
312 _LIBCPP_HIDE_FROM_ABI char_type* epptr() const { return __eout_; }
313
314 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 void pbump(int __n) { __nout_ += __n; }
315
316 _LIBCPP_HIDE_FROM_ABI void __pbump(streamsize __n) { __nout_ += __n; }
317
318 inline _LIBCPP_HIDE_FROM_ABI_SINCE_LLVM8 void setp(char_type* __pbeg, char_type* __pend) {
319 _LIBCPP_ASSERT_VALID_INPUT_RANGE(std::__is_valid_range(__pbeg, __pend), "[pbeg, pend) must be a valid range");
320 __bout_ = __nout_ = __pbeg;
321 __eout_ = __pend;
322 }
323
324 // 27.6.2.4 virtual functions:
325 // 27.6.2.4.1 Locales:
326 virtual void imbue(const locale&) {}
327
328 // 27.6.2.4.2 Buffer management and positioning:
329 virtual basic_streambuf* setbuf(char_type*, streamsize) { return this; }
330 virtual pos_type seekoff(off_type, ios_base::seekdir, ios_base::openmode = ios_base::in | ios_base::out) {
331 return pos_type(off_type(-1));
332 }
333 virtual pos_type seekpos(pos_type, ios_base::openmode = ios_base::in | ios_base::out) {
334 return pos_type(off_type(-1));
335 }
336 virtual int sync() { return 0; }
337
338 // 27.6.2.4.3 Get area:
339 virtual streamsize showmanyc() { return 0; }
340
341 virtual streamsize xsgetn(char_type* __s, streamsize __n) {
342 __check_invariants();
343 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
344
345 int_type __c;
346 streamsize __i = 0;
347 while (__i < __n) {
348 if (gptr() < egptr()) {
349 const streamsize __len = std::min(static_cast<streamsize>(INT_MAX), std::min(egptr() - gptr(), __n - __i));
350 traits_type::copy(__s, gptr(), __len);
351 __s += __len;
352 __i += __len;
353 this->gbump(__len);
354 } else if ((__c = uflow()) != traits_type::eof()) {
355 *__s = traits_type::to_char_type(__c);
356 ++__s;
357 ++__i;
358 } else
359 break;
360 }
361 return __i;
362 }
363
364 virtual int_type underflow() { return traits_type::eof(); }
365 virtual int_type uflow() {
366 __check_invariants();
367 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
368
369 if (underflow() == traits_type::eof())
370 return traits_type::eof();
371 int_type __c = traits_type::to_int_type(*gptr());
372 this->gbump(1);
373 return __c;
374 }
375
376 // 27.6.2.4.4 Putback:
377 virtual int_type pbackfail(int_type = traits_type::eof()) { return traits_type::eof(); }
378
379 // 27.6.2.4.5 Put area:
380 virtual streamsize xsputn(const char_type* __s, streamsize __n) {
381 __check_invariants();
382 auto __guard = std::__make_scope_guard([this] { this->__check_invariants(); });
383
384 streamsize __i = 0;
385 while (__i < __n) {
386 if (pptr() >= epptr()) {
387 if (overflow(traits_type::to_int_type(*__s)) == traits_type::eof())
388 break;
389 ++__s;
390 ++__i;
391 } else {
392 streamsize __chunk_size = std::min(epptr() - pptr(), __n - __i);
393 traits_type::copy(pptr(), __s, __chunk_size);
394 __pbump(n: __chunk_size);
395 __s += __chunk_size;
396 __i += __chunk_size;
397 }
398 }
399 return __i;
400 }
401
402 virtual int_type overflow(int_type = traits_type::eof()) { return traits_type::eof(); }
403
404 // This function checks some invariants of the class (it isn't exhaustive).
405 _LIBCPP_HIDE_FROM_ABI void __check_invariants() const {
406 _LIBCPP_ASSERT_INTERNAL(pbase() <= pptr(), "this is an invariant of the class");
407 _LIBCPP_ASSERT_INTERNAL(pptr() <= epptr(), "this is an invariant of the class");
408
409 _LIBCPP_ASSERT_INTERNAL(eback() <= gptr(), "this is an invariant of the class");
410 _LIBCPP_ASSERT_INTERNAL(gptr() <= egptr(), "this is an invariant of the class");
411 }
412
413private:
414 locale __loc_;
415 char_type* __binp_ = nullptr;
416 char_type* __ninp_ = nullptr;
417 char_type* __einp_ = nullptr;
418 char_type* __bout_ = nullptr;
419 char_type* __nout_ = nullptr;
420 char_type* __eout_ = nullptr;
421
422 template <class _CharT2, class _Traits2, class _Allocator>
423 _LIBCPP_HIDE_FROM_ABI friend basic_istream<_CharT2, _Traits2>&
424 getline(basic_istream<_CharT2, _Traits2>&, basic_string<_CharT2, _Traits2, _Allocator>&, _CharT2);
425};
426
427extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_streambuf<char>;
428
429# if _LIBCPP_HAS_WIDE_CHARACTERS
430extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_streambuf<wchar_t>;
431# endif
432
433_LIBCPP_END_NAMESPACE_STD
434
435_LIBCPP_POP_MACROS
436
437# endif // _LIBCPP_HAS_LOCALIZATION
438
439# if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
440# include <cstdint>
441# include <optional>
442# endif
443#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
444
445#endif // _LIBCPP_STREAMBUF
446