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872d8fea PC |
1 | // Reference-counted versatile string base -*- C++ -*- |
2 | ||
b7ee72de | 3 | // Copyright (C) 2005, 2006 Free Software Foundation, Inc. |
872d8fea PC |
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 2, 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 | // You should have received a copy of the GNU General Public License along | |
17 | // with this library; see the file COPYING. If not, write to the Free | |
83f51799 | 18 | // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, |
872d8fea PC |
19 | // USA. |
20 | ||
21 | // As a special exception, you may use this file as part of a free software | |
22 | // library without restriction. Specifically, if other files instantiate | |
23 | // templates or use macros or inline functions from this file, or you compile | |
24 | // this file and link it with other files to produce an executable, this | |
25 | // file does not by itself cause the resulting executable to be covered by | |
26 | // the GNU General Public License. This exception does not however | |
27 | // invalidate any other reasons why the executable file might be covered by | |
28 | // the GNU General Public License. | |
29 | ||
30 | /** @file ext/rc_string_base.h | |
31 | * This file is a GNU extension to the Standard C++ Library. | |
32 | * This is an internal header file, included by other library headers. | |
33 | * You should not attempt to use it directly. | |
34 | */ | |
35 | ||
36 | #ifndef _RC_STRING_BASE_H | |
37 | #define _RC_STRING_BASE_H 1 | |
38 | ||
39 | #include <bits/atomicity.h> | |
40 | ||
3cbc7af0 BK |
41 | _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) |
42 | ||
872d8fea PC |
43 | /** |
44 | * @if maint | |
45 | * Documentation? What's that? | |
46 | * Nathan Myers <ncm@cantrip.org>. | |
47 | * | |
48 | * A string looks like this: | |
49 | * | |
50 | * @code | |
51 | * [_Rep] | |
52 | * _M_length | |
53 | * [__rc_string_base<char_type>] _M_capacity | |
54 | * _M_dataplus _M_refcount | |
55 | * _M_p ----------------> unnamed array of char_type | |
56 | * @endcode | |
57 | * | |
58 | * Where the _M_p points to the first character in the string, and | |
59 | * you cast it to a pointer-to-_Rep and subtract 1 to get a | |
60 | * pointer to the header. | |
61 | * | |
62 | * This approach has the enormous advantage that a string object | |
63 | * requires only one allocation. All the ugliness is confined | |
64 | * within a single pair of inline functions, which each compile to | |
65 | * a single "add" instruction: _Rep::_M_refdata(), and | |
66 | * __rc_string_base::_M_rep(); and the allocation function which gets a | |
67 | * block of raw bytes and with room enough and constructs a _Rep | |
68 | * object at the front. | |
69 | * | |
70 | * The reason you want _M_data pointing to the character array and | |
71 | * not the _Rep is so that the debugger can see the string | |
72 | * contents. (Probably we should add a non-inline member to get | |
73 | * the _Rep for the debugger to use, so users can check the actual | |
74 | * string length.) | |
75 | * | |
76 | * Note that the _Rep object is a POD so that you can have a | |
77 | * static "empty string" _Rep object already "constructed" before | |
78 | * static constructors have run. The reference-count encoding is | |
79 | * chosen so that a 0 indicates one reference, so you never try to | |
80 | * destroy the empty-string _Rep object. | |
81 | * | |
82 | * All but the last paragraph is considered pretty conventional | |
83 | * for a C++ string implementation. | |
84 | * @endif | |
85 | */ | |
86 | template<typename _CharT, typename _Traits, typename _Alloc> | |
87 | class __rc_string_base | |
88 | : protected __vstring_utility<_CharT, _Traits, _Alloc> | |
89 | { | |
90 | public: | |
91 | typedef _Traits traits_type; | |
92 | typedef typename _Traits::char_type value_type; | |
93 | typedef _Alloc allocator_type; | |
94 | ||
7697e6c6 PC |
95 | typedef __vstring_utility<_CharT, _Traits, _Alloc> _Util_Base; |
96 | typedef typename _Util_Base::_CharT_alloc_type _CharT_alloc_type; | |
872d8fea PC |
97 | typedef typename _CharT_alloc_type::size_type size_type; |
98 | ||
872d8fea | 99 | private: |
872d8fea PC |
100 | // _Rep: string representation |
101 | // Invariants: | |
102 | // 1. String really contains _M_length + 1 characters: due to 21.3.4 | |
103 | // must be kept null-terminated. | |
104 | // 2. _M_capacity >= _M_length | |
105 | // Allocated memory is always (_M_capacity + 1) * sizeof(_CharT). | |
106 | // 3. _M_refcount has three states: | |
107 | // -1: leaked, one reference, no ref-copies allowed, non-const. | |
108 | // 0: one reference, non-const. | |
109 | // n>0: n + 1 references, operations require a lock, const. | |
7697e6c6 | 110 | // 4. All fields == 0 is an empty string, given the extra storage |
872d8fea PC |
111 | // beyond-the-end for a null terminator; thus, the shared |
112 | // empty string representation needs no constructor. | |
113 | struct _Rep | |
114 | { | |
7697e6c6 PC |
115 | union |
116 | { | |
117 | struct | |
118 | { | |
119 | size_type _M_length; | |
120 | size_type _M_capacity; | |
121 | _Atomic_word _M_refcount; | |
122 | } _M_info; | |
123 | ||
124 | // Only for alignment purposes. | |
125 | _CharT _M_align; | |
126 | }; | |
872d8fea | 127 | |
7697e6c6 | 128 | typedef typename _Alloc::template rebind<_Rep>::other _Rep_alloc_type; |
872d8fea PC |
129 | |
130 | _CharT* | |
a5cee480 | 131 | _M_refdata() throw() |
872d8fea PC |
132 | { return reinterpret_cast<_CharT*>(this + 1); } |
133 | ||
a5cee480 PC |
134 | _CharT* |
135 | _M_refcopy() throw() | |
136 | { | |
b7ee72de | 137 | __atomic_add_dispatch(&_M_info._M_refcount, 1); |
a5cee480 PC |
138 | return _M_refdata(); |
139 | } // XXX MT | |
140 | ||
872d8fea PC |
141 | void |
142 | _M_set_length(size_type __n) | |
143 | { | |
7697e6c6 PC |
144 | _M_info._M_refcount = 0; // One reference. |
145 | _M_info._M_length = __n; | |
872d8fea PC |
146 | // grrr. (per 21.3.4) |
147 | // You cannot leave those LWG people alone for a second. | |
486516b6 | 148 | traits_type::assign(_M_refdata()[__n], _CharT()); |
872d8fea PC |
149 | } |
150 | ||
151 | // Create & Destroy | |
152 | static _Rep* | |
153 | _S_create(size_type, size_type, const _Alloc&); | |
154 | ||
155 | void | |
156 | _M_destroy(const _Alloc&) throw(); | |
157 | ||
158 | _CharT* | |
159 | _M_clone(const _Alloc&, size_type __res = 0); | |
160 | }; | |
161 | ||
7697e6c6 PC |
162 | struct _Rep_empty |
163 | : public _Rep | |
872d8fea | 164 | { |
7697e6c6 | 165 | _CharT _M_terminal; |
872d8fea PC |
166 | }; |
167 | ||
7697e6c6 PC |
168 | static _Rep_empty _S_empty_rep; |
169 | ||
486516b6 PC |
170 | // The maximum number of individual char_type elements of an |
171 | // individual string is determined by _S_max_size. This is the | |
172 | // value that will be returned by max_size(). (Whereas npos | |
173 | // is the maximum number of bytes the allocator can allocate.) | |
174 | // If one was to divvy up the theoretical largest size string, | |
175 | // with a terminating character and m _CharT elements, it'd | |
176 | // look like this: | |
177 | // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT) | |
2da7ea25 PC |
178 | // + sizeof(_Rep) - 1 |
179 | // (NB: last two terms for rounding reasons, see _M_create below) | |
486516b6 | 180 | // Solving for m: |
2da7ea25 | 181 | // m = ((npos - 2 * sizeof(_Rep) + 1) / sizeof(_CharT)) - 1 |
7aa6ba76 | 182 | // In addition, this implementation halfs this amount. |
2da7ea25 PC |
183 | enum { _S_max_size = (((static_cast<size_type>(-1) - 2 * sizeof(_Rep) |
184 | + 1) / sizeof(_CharT)) - 1) / 2 }; | |
486516b6 | 185 | |
872d8fea | 186 | // Data Member (private): |
7697e6c6 | 187 | mutable typename _Util_Base::template _Alloc_hider<_Alloc> _M_dataplus; |
872d8fea | 188 | |
7697e6c6 | 189 | void |
872d8fea | 190 | _M_data(_CharT* __p) |
7697e6c6 | 191 | { _M_dataplus._M_p = __p; } |
872d8fea PC |
192 | |
193 | _Rep* | |
194 | _M_rep() const | |
195 | { return &((reinterpret_cast<_Rep*>(_M_data()))[-1]); } | |
196 | ||
872d8fea | 197 | _CharT* |
b6cb8dc2 | 198 | _M_grab(const _Alloc& __alloc) const |
872d8fea | 199 | { |
b6cb8dc2 PC |
200 | return (!_M_is_leaked() && _M_get_allocator() == __alloc) |
201 | ? _M_rep()->_M_refcopy() : _M_rep()->_M_clone(__alloc); | |
872d8fea PC |
202 | } |
203 | ||
204 | void | |
b6cb8dc2 | 205 | _M_dispose() |
872d8fea | 206 | { |
b7ee72de PC |
207 | if (__exchange_and_add_dispatch(&_M_rep()->_M_info._M_refcount, |
208 | -1) <= 0) | |
b6cb8dc2 | 209 | _M_rep()->_M_destroy(_M_get_allocator()); |
872d8fea PC |
210 | } // XXX MT |
211 | ||
7697e6c6 PC |
212 | bool |
213 | _M_is_leaked() const | |
214 | { return _M_rep()->_M_info._M_refcount < 0; } | |
215 | ||
216 | void | |
217 | _M_set_sharable() | |
218 | { _M_rep()->_M_info._M_refcount = 0; } | |
219 | ||
872d8fea PC |
220 | void |
221 | _M_leak_hard(); | |
222 | ||
223 | // _S_construct_aux is used to implement the 21.3.1 para 15 which | |
7697e6c6 | 224 | // requires special behaviour if _InIterator is an integral type |
b6cb8dc2 | 225 | template<typename _InIterator> |
872d8fea PC |
226 | static _CharT* |
227 | _S_construct_aux(_InIterator __beg, _InIterator __end, | |
228 | const _Alloc& __a, __false_type) | |
229 | { | |
230 | typedef typename iterator_traits<_InIterator>::iterator_category _Tag; | |
231 | return _S_construct(__beg, __end, __a, _Tag()); | |
232 | } | |
233 | ||
b6cb8dc2 | 234 | template<typename _InIterator> |
872d8fea PC |
235 | static _CharT* |
236 | _S_construct_aux(_InIterator __beg, _InIterator __end, | |
237 | const _Alloc& __a, __true_type) | |
238 | { return _S_construct(static_cast<size_type>(__beg), | |
239 | static_cast<value_type>(__end), __a); } | |
240 | ||
b6cb8dc2 | 241 | template<typename _InIterator> |
872d8fea PC |
242 | static _CharT* |
243 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a) | |
244 | { | |
245 | typedef typename std::__is_integer<_InIterator>::__type _Integral; | |
246 | return _S_construct_aux(__beg, __end, __a, _Integral()); | |
247 | } | |
248 | ||
249 | // For Input Iterators, used in istreambuf_iterators, etc. | |
b6cb8dc2 | 250 | template<typename _InIterator> |
872d8fea PC |
251 | static _CharT* |
252 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
253 | std::input_iterator_tag); | |
254 | ||
255 | // For forward_iterators up to random_access_iterators, used for | |
256 | // string::iterator, _CharT*, etc. | |
b6cb8dc2 | 257 | template<typename _FwdIterator> |
872d8fea PC |
258 | static _CharT* |
259 | _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a, | |
260 | std::forward_iterator_tag); | |
261 | ||
262 | static _CharT* | |
263 | _S_construct(size_type __req, _CharT __c, const _Alloc& __a); | |
264 | ||
265 | public: | |
486516b6 PC |
266 | size_type |
267 | _M_max_size() const | |
268 | { return size_type(_S_max_size); } | |
269 | ||
872d8fea PC |
270 | _CharT* |
271 | _M_data() const | |
272 | { return _M_dataplus._M_p; } | |
273 | ||
274 | size_type | |
275 | _M_length() const | |
7697e6c6 | 276 | { return _M_rep()->_M_info._M_length; } |
872d8fea PC |
277 | |
278 | size_type | |
279 | _M_capacity() const | |
7697e6c6 | 280 | { return _M_rep()->_M_info._M_capacity; } |
872d8fea PC |
281 | |
282 | bool | |
283 | _M_is_shared() const | |
7697e6c6 | 284 | { return _M_rep()->_M_info._M_refcount > 0; } |
872d8fea PC |
285 | |
286 | void | |
287 | _M_set_leaked() | |
7697e6c6 | 288 | { _M_rep()->_M_info._M_refcount = -1; } |
872d8fea PC |
289 | |
290 | void | |
291 | _M_leak() // for use in begin() & non-const op[] | |
292 | { | |
293 | if (!_M_is_leaked()) | |
294 | _M_leak_hard(); | |
295 | } | |
296 | ||
7697e6c6 PC |
297 | void |
298 | _M_set_length(size_type __n) | |
299 | { _M_rep()->_M_set_length(__n); } | |
300 | ||
872d8fea | 301 | __rc_string_base() |
7697e6c6 | 302 | : _M_dataplus(_Alloc(), _S_empty_rep._M_refcopy()) { } |
a5cee480 | 303 | |
872d8fea PC |
304 | __rc_string_base(const _Alloc& __a); |
305 | ||
306 | __rc_string_base(const __rc_string_base& __rcs); | |
307 | ||
308 | __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a); | |
309 | ||
310 | template<typename _InputIterator> | |
311 | __rc_string_base(_InputIterator __beg, _InputIterator __end, | |
7697e6c6 | 312 | const _Alloc& __a); |
872d8fea PC |
313 | |
314 | ~__rc_string_base() | |
b6cb8dc2 | 315 | { _M_dispose(); } |
872d8fea | 316 | |
cf882919 PC |
317 | allocator_type& |
318 | _M_get_allocator() | |
319 | { return _M_dataplus; } | |
320 | ||
b6cb8dc2 | 321 | const allocator_type& |
872d8fea PC |
322 | _M_get_allocator() const |
323 | { return _M_dataplus; } | |
324 | ||
325 | void | |
7697e6c6 | 326 | _M_swap(__rc_string_base& __rcs); |
872d8fea PC |
327 | |
328 | void | |
329 | _M_assign(const __rc_string_base& __rcs); | |
330 | ||
331 | void | |
332 | _M_reserve(size_type __res); | |
333 | ||
334 | void | |
cf882919 PC |
335 | _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, |
336 | size_type __len2); | |
337 | ||
338 | void | |
339 | _M_erase(size_type __pos, size_type __n); | |
b6105bf2 | 340 | |
7867a3f7 PC |
341 | void |
342 | _M_clear() | |
343 | { _M_erase(size_type(0), _M_length()); } | |
344 | ||
b6105bf2 PC |
345 | bool |
346 | _M_compare(const __rc_string_base&) const | |
347 | { return false; } | |
872d8fea PC |
348 | }; |
349 | ||
7697e6c6 PC |
350 | template<typename _CharT, typename _Traits, typename _Alloc> |
351 | typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep_empty | |
352 | __rc_string_base<_CharT, _Traits, _Alloc>::_S_empty_rep; | |
353 | ||
872d8fea | 354 | template<typename _CharT, typename _Traits, typename _Alloc> |
872d8fea PC |
355 | typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep* |
356 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
357 | _S_create(size_type __capacity, size_type __old_capacity, | |
358 | const _Alloc& __alloc) | |
359 | { | |
360 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
361 | // 83. String::npos vs. string::max_size() | |
486516b6 | 362 | if (__capacity > size_type(_S_max_size)) |
872d8fea PC |
363 | std::__throw_length_error(__N("__rc_string_base::_Rep::_S_create")); |
364 | ||
365 | // The standard places no restriction on allocating more memory | |
366 | // than is strictly needed within this layer at the moment or as | |
367 | // requested by an explicit application call to reserve(). | |
368 | ||
369 | // Many malloc implementations perform quite poorly when an | |
370 | // application attempts to allocate memory in a stepwise fashion | |
371 | // growing each allocation size by only 1 char. Additionally, | |
372 | // it makes little sense to allocate less linear memory than the | |
373 | // natural blocking size of the malloc implementation. | |
374 | // Unfortunately, we would need a somewhat low-level calculation | |
375 | // with tuned parameters to get this perfect for any particular | |
376 | // malloc implementation. Fortunately, generalizations about | |
377 | // common features seen among implementations seems to suffice. | |
378 | ||
379 | // __pagesize need not match the actual VM page size for good | |
380 | // results in practice, thus we pick a common value on the low | |
381 | // side. __malloc_header_size is an estimate of the amount of | |
382 | // overhead per memory allocation (in practice seen N * sizeof | |
383 | // (void*) where N is 0, 2 or 4). According to folklore, | |
384 | // picking this value on the high side is better than | |
385 | // low-balling it (especially when this algorithm is used with | |
386 | // malloc implementations that allocate memory blocks rounded up | |
387 | // to a size which is a power of 2). | |
388 | const size_type __pagesize = 4096; | |
389 | const size_type __malloc_header_size = 4 * sizeof(void*); | |
390 | ||
391 | // The below implements an exponential growth policy, necessary to | |
392 | // meet amortized linear time requirements of the library: see | |
393 | // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. | |
872d8fea | 394 | if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) |
2da7ea25 PC |
395 | { |
396 | __capacity = 2 * __old_capacity; | |
397 | // Never allocate a string bigger than _S_max_size. | |
398 | if (__capacity > size_type(_S_max_size)) | |
399 | __capacity = size_type(_S_max_size); | |
400 | } | |
872d8fea PC |
401 | |
402 | // NB: Need an array of char_type[__capacity], plus a terminating | |
403 | // null char_type() element, plus enough for the _Rep data structure, | |
cf882919 PC |
404 | // plus sizeof(_Rep) - 1 to upper round to a size multiple of |
405 | // sizeof(_Rep). | |
872d8fea | 406 | // Whew. Seemingly so needy, yet so elemental. |
7697e6c6 PC |
407 | size_type __size = ((__capacity + 1) * sizeof(_CharT) |
408 | + 2 * sizeof(_Rep) - 1); | |
872d8fea PC |
409 | |
410 | const size_type __adj_size = __size + __malloc_header_size; | |
411 | if (__adj_size > __pagesize && __capacity > __old_capacity) | |
412 | { | |
413 | const size_type __extra = __pagesize - __adj_size % __pagesize; | |
414 | __capacity += __extra / sizeof(_CharT); | |
486516b6 PC |
415 | if (__capacity > size_type(_S_max_size)) |
416 | __capacity = size_type(_S_max_size); | |
7697e6c6 | 417 | __size = (__capacity + 1) * sizeof(_CharT) + 2 * sizeof(_Rep) - 1; |
872d8fea PC |
418 | } |
419 | ||
420 | // NB: Might throw, but no worries about a leak, mate: _Rep() | |
421 | // does not throw. | |
7697e6c6 PC |
422 | _Rep* __place = _Rep_alloc_type(__alloc).allocate(__size / sizeof(_Rep)); |
423 | _Rep* __p = new (__place) _Rep; | |
424 | __p->_M_info._M_capacity = __capacity; | |
872d8fea PC |
425 | return __p; |
426 | } | |
427 | ||
428 | template<typename _CharT, typename _Traits, typename _Alloc> | |
429 | void | |
430 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
431 | _M_destroy(const _Alloc& __a) throw () | |
432 | { | |
7697e6c6 PC |
433 | const size_type __size = ((_M_info._M_capacity + 1) * sizeof(_CharT) |
434 | + 2 * sizeof(_Rep) - 1); | |
435 | _Rep_alloc_type(__a).deallocate(this, __size / sizeof(_Rep)); | |
872d8fea PC |
436 | } |
437 | ||
438 | template<typename _CharT, typename _Traits, typename _Alloc> | |
439 | _CharT* | |
440 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
441 | _M_clone(const _Alloc& __alloc, size_type __res) | |
442 | { | |
443 | // Requested capacity of the clone. | |
7697e6c6 PC |
444 | const size_type __requested_cap = _M_info._M_length + __res; |
445 | _Rep* __r = _Rep::_S_create(__requested_cap, _M_info._M_capacity, | |
446 | __alloc); | |
872d8fea | 447 | |
7697e6c6 PC |
448 | if (_M_info._M_length) |
449 | _S_copy(__r->_M_refdata(), _M_refdata(), _M_info._M_length); | |
872d8fea | 450 | |
7697e6c6 | 451 | __r->_M_set_length(_M_info._M_length); |
872d8fea PC |
452 | return __r->_M_refdata(); |
453 | } | |
454 | ||
455 | template<typename _CharT, typename _Traits, typename _Alloc> | |
456 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
457 | __rc_string_base(const _Alloc& __a) | |
7697e6c6 | 458 | : _M_dataplus(__a, _S_construct(size_type(), _CharT(), __a)) { } |
872d8fea PC |
459 | |
460 | template<typename _CharT, typename _Traits, typename _Alloc> | |
461 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
462 | __rc_string_base(const __rc_string_base& __rcs) | |
7697e6c6 | 463 | : _M_dataplus(__rcs._M_get_allocator(), |
b6cb8dc2 | 464 | __rcs._M_grab(__rcs._M_get_allocator())) { } |
872d8fea PC |
465 | |
466 | template<typename _CharT, typename _Traits, typename _Alloc> | |
467 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
468 | __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a) | |
7697e6c6 | 469 | : _M_dataplus(__a, _S_construct(__n, __c, __a)) { } |
872d8fea PC |
470 | |
471 | template<typename _CharT, typename _Traits, typename _Alloc> | |
472 | template<typename _InputIterator> | |
473 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
474 | __rc_string_base(_InputIterator __beg, _InputIterator __end, | |
475 | const _Alloc& __a) | |
7697e6c6 | 476 | : _M_dataplus(__a, _S_construct(__beg, __end, __a)) { } |
872d8fea PC |
477 | |
478 | template<typename _CharT, typename _Traits, typename _Alloc> | |
479 | void | |
480 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
481 | _M_leak_hard() | |
482 | { | |
872d8fea | 483 | if (_M_is_shared()) |
cf882919 | 484 | _M_erase(0, 0); |
872d8fea PC |
485 | _M_set_leaked(); |
486 | } | |
487 | ||
488 | // NB: This is the special case for Input Iterators, used in | |
489 | // istreambuf_iterators, etc. | |
490 | // Input Iterators have a cost structure very different from | |
491 | // pointers, calling for a different coding style. | |
492 | template<typename _CharT, typename _Traits, typename _Alloc> | |
493 | template<typename _InIterator> | |
494 | _CharT* | |
495 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
496 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
497 | std::input_iterator_tag) | |
498 | { | |
872d8fea | 499 | if (__beg == __end && __a == _Alloc()) |
7697e6c6 | 500 | return _S_empty_rep._M_refcopy(); |
a5cee480 | 501 | |
872d8fea PC |
502 | // Avoid reallocation for common case. |
503 | _CharT __buf[128]; | |
504 | size_type __len = 0; | |
505 | while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT)) | |
506 | { | |
507 | __buf[__len++] = *__beg; | |
508 | ++__beg; | |
509 | } | |
510 | _Rep* __r = _Rep::_S_create(__len, size_type(0), __a); | |
511 | _S_copy(__r->_M_refdata(), __buf, __len); | |
512 | try | |
513 | { | |
514 | while (__beg != __end) | |
515 | { | |
cf882919 | 516 | if (__len == __r->_M_info._M_capacity) |
872d8fea PC |
517 | { |
518 | // Allocate more space. | |
519 | _Rep* __another = _Rep::_S_create(__len + 1, __len, __a); | |
520 | _S_copy(__another->_M_refdata(), __r->_M_refdata(), __len); | |
521 | __r->_M_destroy(__a); | |
522 | __r = __another; | |
523 | } | |
524 | __r->_M_refdata()[__len++] = *__beg; | |
525 | ++__beg; | |
526 | } | |
527 | } | |
528 | catch(...) | |
529 | { | |
530 | __r->_M_destroy(__a); | |
531 | __throw_exception_again; | |
532 | } | |
533 | __r->_M_set_length(__len); | |
534 | return __r->_M_refdata(); | |
535 | } | |
536 | ||
537 | template<typename _CharT, typename _Traits, typename _Alloc> | |
b6cb8dc2 | 538 | template<typename _InIterator> |
872d8fea PC |
539 | _CharT* |
540 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
541 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
542 | std::forward_iterator_tag) | |
543 | { | |
872d8fea | 544 | if (__beg == __end && __a == _Alloc()) |
7697e6c6 | 545 | return _S_empty_rep._M_refcopy(); |
a5cee480 | 546 | |
872d8fea | 547 | // NB: Not required, but considered best practice. |
7697e6c6 | 548 | if (__builtin_expect(_S_is_null_pointer(__beg) && __beg != __end, 0)) |
872d8fea PC |
549 | std::__throw_logic_error(__N("__rc_string_base::" |
550 | "_S_construct NULL not valid")); | |
551 | ||
552 | const size_type __dnew = static_cast<size_type>(std::distance(__beg, | |
553 | __end)); | |
554 | // Check for out_of_range and length_error exceptions. | |
555 | _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a); | |
556 | try | |
557 | { _S_copy_chars(__r->_M_refdata(), __beg, __end); } | |
558 | catch(...) | |
559 | { | |
560 | __r->_M_destroy(__a); | |
561 | __throw_exception_again; | |
562 | } | |
563 | __r->_M_set_length(__dnew); | |
564 | return __r->_M_refdata(); | |
565 | } | |
566 | ||
567 | template<typename _CharT, typename _Traits, typename _Alloc> | |
568 | _CharT* | |
569 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
570 | _S_construct(size_type __n, _CharT __c, const _Alloc& __a) | |
571 | { | |
872d8fea | 572 | if (__n == 0 && __a == _Alloc()) |
7697e6c6 | 573 | return _S_empty_rep._M_refcopy(); |
a5cee480 | 574 | |
872d8fea PC |
575 | // Check for out_of_range and length_error exceptions. |
576 | _Rep* __r = _Rep::_S_create(__n, size_type(0), __a); | |
577 | if (__n) | |
578 | _S_assign(__r->_M_refdata(), __n, __c); | |
579 | ||
580 | __r->_M_set_length(__n); | |
581 | return __r->_M_refdata(); | |
582 | } | |
583 | ||
7697e6c6 PC |
584 | template<typename _CharT, typename _Traits, typename _Alloc> |
585 | void | |
586 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
587 | _M_swap(__rc_string_base& __rcs) | |
588 | { | |
589 | if (_M_is_leaked()) | |
590 | _M_set_sharable(); | |
591 | if (__rcs._M_is_leaked()) | |
592 | __rcs._M_set_sharable(); | |
593 | ||
594 | _CharT* __tmp = _M_data(); | |
595 | _M_data(__rcs._M_data()); | |
596 | __rcs._M_data(__tmp); | |
f7ace77f PC |
597 | |
598 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
599 | // 431. Swapping containers with unequal allocators. | |
600 | std::__alloc_swap<allocator_type>::_S_do_it(_M_get_allocator(), | |
601 | __rcs._M_get_allocator()); | |
7697e6c6 PC |
602 | } |
603 | ||
872d8fea PC |
604 | template<typename _CharT, typename _Traits, typename _Alloc> |
605 | void | |
606 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
607 | _M_assign(const __rc_string_base& __rcs) | |
608 | { | |
609 | if (_M_rep() != __rcs._M_rep()) | |
610 | { | |
b6cb8dc2 PC |
611 | _CharT* __tmp = __rcs._M_grab(_M_get_allocator()); |
612 | _M_dispose(); | |
872d8fea PC |
613 | _M_data(__tmp); |
614 | } | |
615 | } | |
616 | ||
617 | template<typename _CharT, typename _Traits, typename _Alloc> | |
618 | void | |
619 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
620 | _M_reserve(size_type __res) | |
621 | { | |
cf882919 PC |
622 | // Make sure we don't shrink below the current size. |
623 | if (__res < _M_length()) | |
624 | __res = _M_length(); | |
625 | ||
872d8fea PC |
626 | if (__res != _M_capacity() || _M_is_shared()) |
627 | { | |
b6cb8dc2 PC |
628 | _CharT* __tmp = _M_rep()->_M_clone(_M_get_allocator(), |
629 | __res - _M_length()); | |
630 | _M_dispose(); | |
872d8fea PC |
631 | _M_data(__tmp); |
632 | } | |
633 | } | |
634 | ||
635 | template<typename _CharT, typename _Traits, typename _Alloc> | |
636 | void | |
637 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
cf882919 PC |
638 | _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, |
639 | size_type __len2) | |
872d8fea | 640 | { |
cf882919 PC |
641 | const size_type __how_much = _M_length() - __pos - __len1; |
642 | ||
643 | _Rep* __r = _Rep::_S_create(_M_length() + __len2 - __len1, | |
644 | _M_capacity(), _M_get_allocator()); | |
872d8fea | 645 | |
cf882919 PC |
646 | if (__pos) |
647 | _S_copy(__r->_M_refdata(), _M_data(), __pos); | |
648 | if (__s && __len2) | |
649 | _S_copy(__r->_M_refdata() + __pos, __s, __len2); | |
650 | if (__how_much) | |
651 | _S_copy(__r->_M_refdata() + __pos + __len2, | |
652 | _M_data() + __pos + __len1, __how_much); | |
653 | ||
654 | _M_dispose(); | |
655 | _M_data(__r->_M_refdata()); | |
656 | } | |
657 | ||
658 | template<typename _CharT, typename _Traits, typename _Alloc> | |
659 | void | |
660 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
661 | _M_erase(size_type __pos, size_type __n) | |
662 | { | |
663 | const size_type __new_size = _M_length() - __n; | |
664 | const size_type __how_much = _M_length() - __pos - __n; | |
665 | ||
666 | if (_M_is_shared()) | |
872d8fea PC |
667 | { |
668 | // Must reallocate. | |
b6cb8dc2 PC |
669 | _Rep* __r = _Rep::_S_create(__new_size, _M_capacity(), |
670 | _M_get_allocator()); | |
872d8fea PC |
671 | |
672 | if (__pos) | |
673 | _S_copy(__r->_M_refdata(), _M_data(), __pos); | |
674 | if (__how_much) | |
cf882919 PC |
675 | _S_copy(__r->_M_refdata() + __pos, |
676 | _M_data() + __pos + __n, __how_much); | |
872d8fea | 677 | |
b6cb8dc2 | 678 | _M_dispose(); |
872d8fea PC |
679 | _M_data(__r->_M_refdata()); |
680 | } | |
cf882919 | 681 | else if (__how_much && __n) |
872d8fea PC |
682 | { |
683 | // Work in-place. | |
cf882919 PC |
684 | _S_move(_M_data() + __pos, |
685 | _M_data() + __pos + __n, __how_much); | |
872d8fea | 686 | } |
cf882919 PC |
687 | |
688 | _M_rep()->_M_set_length(__new_size); | |
872d8fea | 689 | } |
b6105bf2 PC |
690 | |
691 | template<> | |
692 | inline bool | |
693 | __rc_string_base<char, std::char_traits<char>, | |
694 | std::allocator<char> >:: | |
695 | _M_compare(const __rc_string_base& __rcs) const | |
696 | { | |
697 | if (_M_rep() == __rcs._M_rep()) | |
698 | return true; | |
699 | return false; | |
700 | } | |
701 | ||
702 | template<> | |
703 | inline bool | |
704 | __rc_string_base<wchar_t, std::char_traits<wchar_t>, | |
705 | std::allocator<wchar_t> >:: | |
706 | _M_compare(const __rc_string_base& __rcs) const | |
707 | { | |
708 | if (_M_rep() == __rcs._M_rep()) | |
709 | return true; | |
710 | return false; | |
711 | } | |
3cbc7af0 BK |
712 | |
713 | _GLIBCXX_END_NAMESPACE | |
872d8fea PC |
714 | |
715 | #endif /* _RC_STRING_BASE_H */ |