1 // Short-string-optimized versatile string base -*- C++ -*-
3 // Copyright (C) 2005, 2006, 2007, 2008, 2009 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 ext/sso_string_base.h
26 * This file is a GNU extension to the Standard C++ Library.
27 * This is an internal header file, included by other library headers.
28 * You should not attempt to use it directly.
31 #ifndef _SSO_STRING_BASE_H
32 #define _SSO_STRING_BASE_H 1
34 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
36 template<typename _CharT, typename _Traits, typename _Alloc>
37 class __sso_string_base
38 : protected __vstring_utility<_CharT, _Traits, _Alloc>
41 typedef _Traits traits_type;
42 typedef typename _Traits::char_type value_type;
44 typedef __vstring_utility<_CharT, _Traits, _Alloc> _Util_Base;
45 typedef typename _Util_Base::_CharT_alloc_type _CharT_alloc_type;
46 typedef typename _CharT_alloc_type::size_type size_type;
50 typename _Util_Base::template _Alloc_hider<_CharT_alloc_type>
52 size_type _M_string_length;
54 enum { _S_local_capacity = 15 };
58 _CharT _M_local_data[_S_local_capacity + 1];
59 size_type _M_allocated_capacity;
64 { _M_dataplus._M_p = __p; }
67 _M_length(size_type __length)
68 { _M_string_length = __length; }
71 _M_capacity(size_type __capacity)
72 { _M_allocated_capacity = __capacity; }
76 { return _M_data() == _M_local_data; }
80 _M_create(size_type&, size_type);
86 _M_destroy(_M_allocated_capacity);
90 _M_destroy(size_type __size) throw()
91 { _M_get_allocator().deallocate(_M_data(), __size + 1); }
93 // _M_construct_aux is used to implement the 21.3.1 para 15 which
94 // requires special behaviour if _InIterator is an integral type
95 template<typename _InIterator>
97 _M_construct_aux(_InIterator __beg, _InIterator __end,
100 typedef typename iterator_traits<_InIterator>::iterator_category _Tag;
101 _M_construct(__beg, __end, _Tag());
104 // _GLIBCXX_RESOLVE_LIB_DEFECTS
105 // 438. Ambiguity in the "do the right thing" clause
106 template<typename _Integer>
108 _M_construct_aux(_Integer __beg, _Integer __end, std::__true_type)
109 { _M_construct(static_cast<size_type>(__beg), __end); }
111 template<typename _InIterator>
113 _M_construct(_InIterator __beg, _InIterator __end)
115 typedef typename std::__is_integer<_InIterator>::__type _Integral;
116 _M_construct_aux(__beg, __end, _Integral());
119 // For Input Iterators, used in istreambuf_iterators, etc.
120 template<typename _InIterator>
122 _M_construct(_InIterator __beg, _InIterator __end,
123 std::input_iterator_tag);
125 // For forward_iterators up to random_access_iterators, used for
126 // string::iterator, _CharT*, etc.
127 template<typename _FwdIterator>
129 _M_construct(_FwdIterator __beg, _FwdIterator __end,
130 std::forward_iterator_tag);
133 _M_construct(size_type __req, _CharT __c);
138 { return (_M_get_allocator().max_size() - 1) / 2; }
142 { return _M_dataplus._M_p; }
146 { return _M_string_length; }
151 return _M_is_local() ? size_type(_S_local_capacity)
152 : _M_allocated_capacity;
166 _M_set_length(size_type __n)
169 traits_type::assign(_M_data()[__n], _CharT());
173 : _M_dataplus(_M_local_data)
174 { _M_set_length(0); }
176 __sso_string_base(const _Alloc& __a);
178 __sso_string_base(const __sso_string_base& __rcs);
180 #ifdef __GXX_EXPERIMENTAL_CXX0X__
181 __sso_string_base(__sso_string_base&& __rcs);
184 __sso_string_base(size_type __n, _CharT __c, const _Alloc& __a);
186 template<typename _InputIterator>
187 __sso_string_base(_InputIterator __beg, _InputIterator __end,
195 { return _M_dataplus; }
197 const _CharT_alloc_type&
198 _M_get_allocator() const
199 { return _M_dataplus; }
202 _M_swap(__sso_string_base& __rcs);
205 _M_assign(const __sso_string_base& __rcs);
208 _M_reserve(size_type __res);
211 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
215 _M_erase(size_type __pos, size_type __n);
219 { _M_set_length(0); }
222 _M_compare(const __sso_string_base&) const
226 template<typename _CharT, typename _Traits, typename _Alloc>
228 __sso_string_base<_CharT, _Traits, _Alloc>::
229 _M_swap(__sso_string_base& __rcs)
231 // _GLIBCXX_RESOLVE_LIB_DEFECTS
232 // 431. Swapping containers with unequal allocators.
233 std::__alloc_swap<_CharT_alloc_type>::_S_do_it(_M_get_allocator(),
234 __rcs._M_get_allocator());
237 if (__rcs._M_is_local())
239 if (_M_length() && __rcs._M_length())
241 _CharT __tmp_data[_S_local_capacity + 1];
242 traits_type::copy(__tmp_data, __rcs._M_local_data,
243 _S_local_capacity + 1);
244 traits_type::copy(__rcs._M_local_data, _M_local_data,
245 _S_local_capacity + 1);
246 traits_type::copy(_M_local_data, __tmp_data,
247 _S_local_capacity + 1);
249 else if (__rcs._M_length())
251 traits_type::copy(_M_local_data, __rcs._M_local_data,
252 _S_local_capacity + 1);
253 _M_length(__rcs._M_length());
254 __rcs._M_set_length(0);
257 else if (_M_length())
259 traits_type::copy(__rcs._M_local_data, _M_local_data,
260 _S_local_capacity + 1);
261 __rcs._M_length(_M_length());
268 const size_type __tmp_capacity = __rcs._M_allocated_capacity;
269 traits_type::copy(__rcs._M_local_data, _M_local_data,
270 _S_local_capacity + 1);
271 _M_data(__rcs._M_data());
272 __rcs._M_data(__rcs._M_local_data);
273 _M_capacity(__tmp_capacity);
277 const size_type __tmp_capacity = _M_allocated_capacity;
278 if (__rcs._M_is_local())
280 traits_type::copy(_M_local_data, __rcs._M_local_data,
281 _S_local_capacity + 1);
282 __rcs._M_data(_M_data());
283 _M_data(_M_local_data);
287 _CharT* __tmp_ptr = _M_data();
288 _M_data(__rcs._M_data());
289 __rcs._M_data(__tmp_ptr);
290 _M_capacity(__rcs._M_allocated_capacity);
292 __rcs._M_capacity(__tmp_capacity);
295 const size_type __tmp_length = _M_length();
296 _M_length(__rcs._M_length());
297 __rcs._M_length(__tmp_length);
300 template<typename _CharT, typename _Traits, typename _Alloc>
302 __sso_string_base<_CharT, _Traits, _Alloc>::
303 _M_create(size_type& __capacity, size_type __old_capacity)
305 // _GLIBCXX_RESOLVE_LIB_DEFECTS
306 // 83. String::npos vs. string::max_size()
307 if (__capacity > _M_max_size())
308 std::__throw_length_error(__N("__sso_string_base::_M_create"));
310 // The below implements an exponential growth policy, necessary to
311 // meet amortized linear time requirements of the library: see
312 // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
313 if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
315 __capacity = 2 * __old_capacity;
316 // Never allocate a string bigger than max_size.
317 if (__capacity > _M_max_size())
318 __capacity = _M_max_size();
321 // NB: Need an array of char_type[__capacity], plus a terminating
322 // null char_type() element.
323 return _M_get_allocator().allocate(__capacity + 1);
326 template<typename _CharT, typename _Traits, typename _Alloc>
327 __sso_string_base<_CharT, _Traits, _Alloc>::
328 __sso_string_base(const _Alloc& __a)
329 : _M_dataplus(__a, _M_local_data)
330 { _M_set_length(0); }
332 template<typename _CharT, typename _Traits, typename _Alloc>
333 __sso_string_base<_CharT, _Traits, _Alloc>::
334 __sso_string_base(const __sso_string_base& __rcs)
335 : _M_dataplus(__rcs._M_get_allocator(), _M_local_data)
336 { _M_construct(__rcs._M_data(), __rcs._M_data() + __rcs._M_length()); }
338 #ifdef __GXX_EXPERIMENTAL_CXX0X__
339 template<typename _CharT, typename _Traits, typename _Alloc>
340 __sso_string_base<_CharT, _Traits, _Alloc>::
341 __sso_string_base(__sso_string_base&& __rcs)
342 : _M_dataplus(__rcs._M_get_allocator(), _M_local_data)
344 if (__rcs._M_is_local())
346 if (__rcs._M_length())
347 traits_type::copy(_M_local_data, __rcs._M_local_data,
348 _S_local_capacity + 1);
352 _M_data(__rcs._M_data());
353 _M_capacity(__rcs._M_allocated_capacity);
356 _M_length(__rcs._M_length());
358 __rcs._M_data(__rcs._M_local_data);
362 template<typename _CharT, typename _Traits, typename _Alloc>
363 __sso_string_base<_CharT, _Traits, _Alloc>::
364 __sso_string_base(size_type __n, _CharT __c, const _Alloc& __a)
365 : _M_dataplus(__a, _M_local_data)
366 { _M_construct(__n, __c); }
368 template<typename _CharT, typename _Traits, typename _Alloc>
369 template<typename _InputIterator>
370 __sso_string_base<_CharT, _Traits, _Alloc>::
371 __sso_string_base(_InputIterator __beg, _InputIterator __end,
373 : _M_dataplus(__a, _M_local_data)
374 { _M_construct(__beg, __end); }
376 // NB: This is the special case for Input Iterators, used in
377 // istreambuf_iterators, etc.
378 // Input Iterators have a cost structure very different from
379 // pointers, calling for a different coding style.
380 template<typename _CharT, typename _Traits, typename _Alloc>
381 template<typename _InIterator>
383 __sso_string_base<_CharT, _Traits, _Alloc>::
384 _M_construct(_InIterator __beg, _InIterator __end,
385 std::input_iterator_tag)
388 size_type __capacity = size_type(_S_local_capacity);
390 while (__beg != __end && __len < __capacity)
392 _M_data()[__len++] = *__beg;
398 while (__beg != __end)
400 if (__len == __capacity)
402 // Allocate more space.
403 __capacity = __len + 1;
404 _CharT* __another = _M_create(__capacity, __len);
405 _S_copy(__another, _M_data(), __len);
408 _M_capacity(__capacity);
410 _M_data()[__len++] = *__beg;
417 __throw_exception_again;
420 _M_set_length(__len);
423 template<typename _CharT, typename _Traits, typename _Alloc>
424 template<typename _InIterator>
426 __sso_string_base<_CharT, _Traits, _Alloc>::
427 _M_construct(_InIterator __beg, _InIterator __end,
428 std::forward_iterator_tag)
430 // NB: Not required, but considered best practice.
431 if (__is_null_pointer(__beg) && __beg != __end)
432 std::__throw_logic_error(__N("__sso_string_base::"
433 "_M_construct NULL not valid"));
435 size_type __dnew = static_cast<size_type>(std::distance(__beg, __end));
437 if (__dnew > size_type(_S_local_capacity))
439 _M_data(_M_create(__dnew, size_type(0)));
443 // Check for out_of_range and length_error exceptions.
445 { _S_copy_chars(_M_data(), __beg, __end); }
449 __throw_exception_again;
452 _M_set_length(__dnew);
455 template<typename _CharT, typename _Traits, typename _Alloc>
457 __sso_string_base<_CharT, _Traits, _Alloc>::
458 _M_construct(size_type __n, _CharT __c)
460 if (__n > size_type(_S_local_capacity))
462 _M_data(_M_create(__n, size_type(0)));
467 _S_assign(_M_data(), __n, __c);
472 template<typename _CharT, typename _Traits, typename _Alloc>
474 __sso_string_base<_CharT, _Traits, _Alloc>::
475 _M_assign(const __sso_string_base& __rcs)
479 const size_type __rsize = __rcs._M_length();
480 const size_type __capacity = _M_capacity();
482 if (__rsize > __capacity)
484 size_type __new_capacity = __rsize;
485 _CharT* __tmp = _M_create(__new_capacity, __capacity);
488 _M_capacity(__new_capacity);
492 _S_copy(_M_data(), __rcs._M_data(), __rsize);
494 _M_set_length(__rsize);
498 template<typename _CharT, typename _Traits, typename _Alloc>
500 __sso_string_base<_CharT, _Traits, _Alloc>::
501 _M_reserve(size_type __res)
503 // Make sure we don't shrink below the current size.
504 if (__res < _M_length())
507 const size_type __capacity = _M_capacity();
508 if (__res != __capacity)
510 if (__res > __capacity
511 || __res > size_type(_S_local_capacity))
513 _CharT* __tmp = _M_create(__res, __capacity);
514 _S_copy(__tmp, _M_data(), _M_length() + 1);
519 else if (!_M_is_local())
521 _S_copy(_M_local_data, _M_data(), _M_length() + 1);
522 _M_destroy(__capacity);
523 _M_data(_M_local_data);
528 template<typename _CharT, typename _Traits, typename _Alloc>
530 __sso_string_base<_CharT, _Traits, _Alloc>::
531 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
532 const size_type __len2)
534 const size_type __how_much = _M_length() - __pos - __len1;
536 size_type __new_capacity = _M_length() + __len2 - __len1;
537 _CharT* __r = _M_create(__new_capacity, _M_capacity());
540 _S_copy(__r, _M_data(), __pos);
542 _S_copy(__r + __pos, __s, __len2);
544 _S_copy(__r + __pos + __len2,
545 _M_data() + __pos + __len1, __how_much);
549 _M_capacity(__new_capacity);
552 template<typename _CharT, typename _Traits, typename _Alloc>
554 __sso_string_base<_CharT, _Traits, _Alloc>::
555 _M_erase(size_type __pos, size_type __n)
557 const size_type __how_much = _M_length() - __pos - __n;
559 if (__how_much && __n)
560 _S_move(_M_data() + __pos, _M_data() + __pos + __n,
563 _M_set_length(_M_length() - __n);
566 _GLIBCXX_END_NAMESPACE
568 #endif /* _SSO_STRING_BASE_H */