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872d8fea PC |
1 | // Reference-counted versatile string base -*- C++ -*- |
2 | ||
bc2631e0 | 3 | // Copyright (C) 2005, 2006, 2007, 2008, 2009 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 | |
748086b7 | 8 | // Free Software Foundation; either version 3, or (at your option) |
872d8fea PC |
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 | ||
748086b7 JJ |
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/>. | |
872d8fea PC |
24 | |
25 | /** @file ext/rc_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. | |
29 | */ | |
30 | ||
31 | #ifndef _RC_STRING_BASE_H | |
32 | #define _RC_STRING_BASE_H 1 | |
33 | ||
2e362c74 | 34 | #include <ext/atomicity.h> |
6116ca65 | 35 | #include <bits/stl_iterator_base_funcs.h> |
872d8fea | 36 | |
3cbc7af0 BK |
37 | _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) |
38 | ||
872d8fea | 39 | /** |
872d8fea PC |
40 | * Documentation? What's that? |
41 | * Nathan Myers <ncm@cantrip.org>. | |
42 | * | |
43 | * A string looks like this: | |
44 | * | |
45 | * @code | |
46 | * [_Rep] | |
47 | * _M_length | |
48 | * [__rc_string_base<char_type>] _M_capacity | |
49 | * _M_dataplus _M_refcount | |
50 | * _M_p ----------------> unnamed array of char_type | |
51 | * @endcode | |
52 | * | |
53 | * Where the _M_p points to the first character in the string, and | |
54 | * you cast it to a pointer-to-_Rep and subtract 1 to get a | |
55 | * pointer to the header. | |
56 | * | |
57 | * This approach has the enormous advantage that a string object | |
58 | * requires only one allocation. All the ugliness is confined | |
59 | * within a single pair of inline functions, which each compile to | |
60 | * a single "add" instruction: _Rep::_M_refdata(), and | |
61 | * __rc_string_base::_M_rep(); and the allocation function which gets a | |
62 | * block of raw bytes and with room enough and constructs a _Rep | |
63 | * object at the front. | |
64 | * | |
65 | * The reason you want _M_data pointing to the character array and | |
66 | * not the _Rep is so that the debugger can see the string | |
67 | * contents. (Probably we should add a non-inline member to get | |
68 | * the _Rep for the debugger to use, so users can check the actual | |
69 | * string length.) | |
70 | * | |
71 | * Note that the _Rep object is a POD so that you can have a | |
72 | * static "empty string" _Rep object already "constructed" before | |
73 | * static constructors have run. The reference-count encoding is | |
74 | * chosen so that a 0 indicates one reference, so you never try to | |
75 | * destroy the empty-string _Rep object. | |
76 | * | |
77 | * All but the last paragraph is considered pretty conventional | |
78 | * for a C++ string implementation. | |
872d8fea PC |
79 | */ |
80 | template<typename _CharT, typename _Traits, typename _Alloc> | |
81 | class __rc_string_base | |
82 | : protected __vstring_utility<_CharT, _Traits, _Alloc> | |
83 | { | |
84 | public: | |
85 | typedef _Traits traits_type; | |
86 | typedef typename _Traits::char_type value_type; | |
87 | typedef _Alloc allocator_type; | |
88 | ||
7697e6c6 PC |
89 | typedef __vstring_utility<_CharT, _Traits, _Alloc> _Util_Base; |
90 | typedef typename _Util_Base::_CharT_alloc_type _CharT_alloc_type; | |
872d8fea PC |
91 | typedef typename _CharT_alloc_type::size_type size_type; |
92 | ||
872d8fea | 93 | private: |
872d8fea PC |
94 | // _Rep: string representation |
95 | // Invariants: | |
96 | // 1. String really contains _M_length + 1 characters: due to 21.3.4 | |
97 | // must be kept null-terminated. | |
98 | // 2. _M_capacity >= _M_length | |
99 | // Allocated memory is always (_M_capacity + 1) * sizeof(_CharT). | |
100 | // 3. _M_refcount has three states: | |
101 | // -1: leaked, one reference, no ref-copies allowed, non-const. | |
102 | // 0: one reference, non-const. | |
103 | // n>0: n + 1 references, operations require a lock, const. | |
7697e6c6 | 104 | // 4. All fields == 0 is an empty string, given the extra storage |
872d8fea PC |
105 | // beyond-the-end for a null terminator; thus, the shared |
106 | // empty string representation needs no constructor. | |
107 | struct _Rep | |
108 | { | |
7697e6c6 PC |
109 | union |
110 | { | |
111 | struct | |
112 | { | |
113 | size_type _M_length; | |
114 | size_type _M_capacity; | |
115 | _Atomic_word _M_refcount; | |
116 | } _M_info; | |
117 | ||
118 | // Only for alignment purposes. | |
119 | _CharT _M_align; | |
120 | }; | |
872d8fea | 121 | |
7697e6c6 | 122 | typedef typename _Alloc::template rebind<_Rep>::other _Rep_alloc_type; |
872d8fea PC |
123 | |
124 | _CharT* | |
a5cee480 | 125 | _M_refdata() throw() |
872d8fea PC |
126 | { return reinterpret_cast<_CharT*>(this + 1); } |
127 | ||
a5cee480 PC |
128 | _CharT* |
129 | _M_refcopy() throw() | |
130 | { | |
b7ee72de | 131 | __atomic_add_dispatch(&_M_info._M_refcount, 1); |
a5cee480 PC |
132 | return _M_refdata(); |
133 | } // XXX MT | |
134 | ||
872d8fea PC |
135 | void |
136 | _M_set_length(size_type __n) | |
137 | { | |
7697e6c6 PC |
138 | _M_info._M_refcount = 0; // One reference. |
139 | _M_info._M_length = __n; | |
872d8fea PC |
140 | // grrr. (per 21.3.4) |
141 | // You cannot leave those LWG people alone for a second. | |
486516b6 | 142 | traits_type::assign(_M_refdata()[__n], _CharT()); |
872d8fea PC |
143 | } |
144 | ||
145 | // Create & Destroy | |
146 | static _Rep* | |
147 | _S_create(size_type, size_type, const _Alloc&); | |
148 | ||
149 | void | |
150 | _M_destroy(const _Alloc&) throw(); | |
151 | ||
152 | _CharT* | |
153 | _M_clone(const _Alloc&, size_type __res = 0); | |
154 | }; | |
155 | ||
7697e6c6 PC |
156 | struct _Rep_empty |
157 | : public _Rep | |
872d8fea | 158 | { |
7697e6c6 | 159 | _CharT _M_terminal; |
872d8fea PC |
160 | }; |
161 | ||
7697e6c6 PC |
162 | static _Rep_empty _S_empty_rep; |
163 | ||
486516b6 PC |
164 | // The maximum number of individual char_type elements of an |
165 | // individual string is determined by _S_max_size. This is the | |
166 | // value that will be returned by max_size(). (Whereas npos | |
167 | // is the maximum number of bytes the allocator can allocate.) | |
168 | // If one was to divvy up the theoretical largest size string, | |
169 | // with a terminating character and m _CharT elements, it'd | |
170 | // look like this: | |
171 | // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT) | |
2da7ea25 PC |
172 | // + sizeof(_Rep) - 1 |
173 | // (NB: last two terms for rounding reasons, see _M_create below) | |
486516b6 | 174 | // Solving for m: |
2da7ea25 | 175 | // m = ((npos - 2 * sizeof(_Rep) + 1) / sizeof(_CharT)) - 1 |
28dac70a | 176 | // In addition, this implementation halves this amount. |
2da7ea25 PC |
177 | enum { _S_max_size = (((static_cast<size_type>(-1) - 2 * sizeof(_Rep) |
178 | + 1) / sizeof(_CharT)) - 1) / 2 }; | |
486516b6 | 179 | |
872d8fea | 180 | // Data Member (private): |
7697e6c6 | 181 | mutable typename _Util_Base::template _Alloc_hider<_Alloc> _M_dataplus; |
872d8fea | 182 | |
7697e6c6 | 183 | void |
872d8fea | 184 | _M_data(_CharT* __p) |
7697e6c6 | 185 | { _M_dataplus._M_p = __p; } |
872d8fea PC |
186 | |
187 | _Rep* | |
188 | _M_rep() const | |
189 | { return &((reinterpret_cast<_Rep*>(_M_data()))[-1]); } | |
190 | ||
872d8fea | 191 | _CharT* |
b6cb8dc2 | 192 | _M_grab(const _Alloc& __alloc) const |
872d8fea | 193 | { |
b6cb8dc2 PC |
194 | return (!_M_is_leaked() && _M_get_allocator() == __alloc) |
195 | ? _M_rep()->_M_refcopy() : _M_rep()->_M_clone(__alloc); | |
872d8fea PC |
196 | } |
197 | ||
198 | void | |
b6cb8dc2 | 199 | _M_dispose() |
872d8fea | 200 | { |
b7ee72de PC |
201 | if (__exchange_and_add_dispatch(&_M_rep()->_M_info._M_refcount, |
202 | -1) <= 0) | |
b6cb8dc2 | 203 | _M_rep()->_M_destroy(_M_get_allocator()); |
872d8fea PC |
204 | } // XXX MT |
205 | ||
7697e6c6 PC |
206 | bool |
207 | _M_is_leaked() const | |
208 | { return _M_rep()->_M_info._M_refcount < 0; } | |
209 | ||
210 | void | |
211 | _M_set_sharable() | |
212 | { _M_rep()->_M_info._M_refcount = 0; } | |
213 | ||
872d8fea PC |
214 | void |
215 | _M_leak_hard(); | |
216 | ||
217 | // _S_construct_aux is used to implement the 21.3.1 para 15 which | |
7697e6c6 | 218 | // requires special behaviour if _InIterator is an integral type |
b6cb8dc2 | 219 | template<typename _InIterator> |
872d8fea PC |
220 | static _CharT* |
221 | _S_construct_aux(_InIterator __beg, _InIterator __end, | |
78a53887 | 222 | const _Alloc& __a, std::__false_type) |
872d8fea PC |
223 | { |
224 | typedef typename iterator_traits<_InIterator>::iterator_category _Tag; | |
225 | return _S_construct(__beg, __end, __a, _Tag()); | |
226 | } | |
227 | ||
25959e29 PC |
228 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
229 | // 438. Ambiguity in the "do the right thing" clause | |
230 | template<typename _Integer> | |
872d8fea | 231 | static _CharT* |
25959e29 | 232 | _S_construct_aux(_Integer __beg, _Integer __end, |
78a53887 | 233 | const _Alloc& __a, std::__true_type) |
574f3664 | 234 | { return _S_construct(static_cast<size_type>(__beg), __end, __a); } |
872d8fea | 235 | |
b6cb8dc2 | 236 | template<typename _InIterator> |
872d8fea PC |
237 | static _CharT* |
238 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a) | |
239 | { | |
240 | typedef typename std::__is_integer<_InIterator>::__type _Integral; | |
241 | return _S_construct_aux(__beg, __end, __a, _Integral()); | |
242 | } | |
243 | ||
244 | // For Input Iterators, used in istreambuf_iterators, etc. | |
b6cb8dc2 | 245 | template<typename _InIterator> |
872d8fea PC |
246 | static _CharT* |
247 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
248 | std::input_iterator_tag); | |
249 | ||
250 | // For forward_iterators up to random_access_iterators, used for | |
251 | // string::iterator, _CharT*, etc. | |
b6cb8dc2 | 252 | template<typename _FwdIterator> |
872d8fea PC |
253 | static _CharT* |
254 | _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a, | |
255 | std::forward_iterator_tag); | |
256 | ||
257 | static _CharT* | |
258 | _S_construct(size_type __req, _CharT __c, const _Alloc& __a); | |
259 | ||
260 | public: | |
486516b6 PC |
261 | size_type |
262 | _M_max_size() const | |
263 | { return size_type(_S_max_size); } | |
264 | ||
872d8fea PC |
265 | _CharT* |
266 | _M_data() const | |
267 | { return _M_dataplus._M_p; } | |
268 | ||
269 | size_type | |
270 | _M_length() const | |
7697e6c6 | 271 | { return _M_rep()->_M_info._M_length; } |
872d8fea PC |
272 | |
273 | size_type | |
274 | _M_capacity() const | |
7697e6c6 | 275 | { return _M_rep()->_M_info._M_capacity; } |
872d8fea PC |
276 | |
277 | bool | |
278 | _M_is_shared() const | |
7697e6c6 | 279 | { return _M_rep()->_M_info._M_refcount > 0; } |
872d8fea PC |
280 | |
281 | void | |
282 | _M_set_leaked() | |
7697e6c6 | 283 | { _M_rep()->_M_info._M_refcount = -1; } |
872d8fea PC |
284 | |
285 | void | |
286 | _M_leak() // for use in begin() & non-const op[] | |
287 | { | |
288 | if (!_M_is_leaked()) | |
289 | _M_leak_hard(); | |
290 | } | |
291 | ||
7697e6c6 PC |
292 | void |
293 | _M_set_length(size_type __n) | |
294 | { _M_rep()->_M_set_length(__n); } | |
295 | ||
872d8fea | 296 | __rc_string_base() |
053cc380 | 297 | : _M_dataplus(_S_empty_rep._M_refcopy()) { } |
a5cee480 | 298 | |
872d8fea PC |
299 | __rc_string_base(const _Alloc& __a); |
300 | ||
301 | __rc_string_base(const __rc_string_base& __rcs); | |
302 | ||
053cc380 PC |
303 | #ifdef __GXX_EXPERIMENTAL_CXX0X__ |
304 | __rc_string_base(__rc_string_base&& __rcs) | |
305 | : _M_dataplus(__rcs._M_get_allocator(), __rcs._M_data()) | |
988499f4 | 306 | { __rcs._M_data(_S_empty_rep._M_refcopy()); } |
053cc380 PC |
307 | #endif |
308 | ||
872d8fea PC |
309 | __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a); |
310 | ||
311 | template<typename _InputIterator> | |
312 | __rc_string_base(_InputIterator __beg, _InputIterator __end, | |
7697e6c6 | 313 | const _Alloc& __a); |
872d8fea PC |
314 | |
315 | ~__rc_string_base() | |
b6cb8dc2 | 316 | { _M_dispose(); } |
872d8fea | 317 | |
cf882919 PC |
318 | allocator_type& |
319 | _M_get_allocator() | |
320 | { return _M_dataplus; } | |
321 | ||
b6cb8dc2 | 322 | const allocator_type& |
872d8fea PC |
323 | _M_get_allocator() const |
324 | { return _M_dataplus; } | |
325 | ||
326 | void | |
7697e6c6 | 327 | _M_swap(__rc_string_base& __rcs); |
872d8fea PC |
328 | |
329 | void | |
330 | _M_assign(const __rc_string_base& __rcs); | |
331 | ||
332 | void | |
333 | _M_reserve(size_type __res); | |
334 | ||
335 | void | |
cf882919 PC |
336 | _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, |
337 | size_type __len2); | |
338 | ||
339 | void | |
340 | _M_erase(size_type __pos, size_type __n); | |
b6105bf2 | 341 | |
7867a3f7 PC |
342 | void |
343 | _M_clear() | |
344 | { _M_erase(size_type(0), _M_length()); } | |
345 | ||
b6105bf2 PC |
346 | bool |
347 | _M_compare(const __rc_string_base&) const | |
348 | { return false; } | |
872d8fea PC |
349 | }; |
350 | ||
7697e6c6 PC |
351 | template<typename _CharT, typename _Traits, typename _Alloc> |
352 | typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep_empty | |
353 | __rc_string_base<_CharT, _Traits, _Alloc>::_S_empty_rep; | |
354 | ||
872d8fea | 355 | template<typename _CharT, typename _Traits, typename _Alloc> |
872d8fea PC |
356 | typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep* |
357 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
358 | _S_create(size_type __capacity, size_type __old_capacity, | |
359 | const _Alloc& __alloc) | |
360 | { | |
361 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
362 | // 83. String::npos vs. string::max_size() | |
486516b6 | 363 | if (__capacity > size_type(_S_max_size)) |
872d8fea PC |
364 | std::__throw_length_error(__N("__rc_string_base::_Rep::_S_create")); |
365 | ||
366 | // The standard places no restriction on allocating more memory | |
367 | // than is strictly needed within this layer at the moment or as | |
368 | // requested by an explicit application call to reserve(). | |
369 | ||
370 | // Many malloc implementations perform quite poorly when an | |
371 | // application attempts to allocate memory in a stepwise fashion | |
372 | // growing each allocation size by only 1 char. Additionally, | |
373 | // it makes little sense to allocate less linear memory than the | |
374 | // natural blocking size of the malloc implementation. | |
375 | // Unfortunately, we would need a somewhat low-level calculation | |
376 | // with tuned parameters to get this perfect for any particular | |
377 | // malloc implementation. Fortunately, generalizations about | |
378 | // common features seen among implementations seems to suffice. | |
379 | ||
380 | // __pagesize need not match the actual VM page size for good | |
381 | // results in practice, thus we pick a common value on the low | |
382 | // side. __malloc_header_size is an estimate of the amount of | |
383 | // overhead per memory allocation (in practice seen N * sizeof | |
384 | // (void*) where N is 0, 2 or 4). According to folklore, | |
385 | // picking this value on the high side is better than | |
386 | // low-balling it (especially when this algorithm is used with | |
387 | // malloc implementations that allocate memory blocks rounded up | |
388 | // to a size which is a power of 2). | |
389 | const size_type __pagesize = 4096; | |
390 | const size_type __malloc_header_size = 4 * sizeof(void*); | |
391 | ||
392 | // The below implements an exponential growth policy, necessary to | |
393 | // meet amortized linear time requirements of the library: see | |
394 | // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. | |
872d8fea | 395 | if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) |
2da7ea25 PC |
396 | { |
397 | __capacity = 2 * __old_capacity; | |
398 | // Never allocate a string bigger than _S_max_size. | |
399 | if (__capacity > size_type(_S_max_size)) | |
400 | __capacity = size_type(_S_max_size); | |
401 | } | |
872d8fea PC |
402 | |
403 | // NB: Need an array of char_type[__capacity], plus a terminating | |
404 | // null char_type() element, plus enough for the _Rep data structure, | |
cf882919 PC |
405 | // plus sizeof(_Rep) - 1 to upper round to a size multiple of |
406 | // sizeof(_Rep). | |
872d8fea | 407 | // Whew. Seemingly so needy, yet so elemental. |
7697e6c6 PC |
408 | size_type __size = ((__capacity + 1) * sizeof(_CharT) |
409 | + 2 * sizeof(_Rep) - 1); | |
872d8fea PC |
410 | |
411 | const size_type __adj_size = __size + __malloc_header_size; | |
412 | if (__adj_size > __pagesize && __capacity > __old_capacity) | |
413 | { | |
414 | const size_type __extra = __pagesize - __adj_size % __pagesize; | |
415 | __capacity += __extra / sizeof(_CharT); | |
486516b6 PC |
416 | if (__capacity > size_type(_S_max_size)) |
417 | __capacity = size_type(_S_max_size); | |
7697e6c6 | 418 | __size = (__capacity + 1) * sizeof(_CharT) + 2 * sizeof(_Rep) - 1; |
872d8fea PC |
419 | } |
420 | ||
421 | // NB: Might throw, but no worries about a leak, mate: _Rep() | |
422 | // does not throw. | |
7697e6c6 PC |
423 | _Rep* __place = _Rep_alloc_type(__alloc).allocate(__size / sizeof(_Rep)); |
424 | _Rep* __p = new (__place) _Rep; | |
425 | __p->_M_info._M_capacity = __capacity; | |
872d8fea PC |
426 | return __p; |
427 | } | |
428 | ||
429 | template<typename _CharT, typename _Traits, typename _Alloc> | |
430 | void | |
431 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
432 | _M_destroy(const _Alloc& __a) throw () | |
433 | { | |
7697e6c6 PC |
434 | const size_type __size = ((_M_info._M_capacity + 1) * sizeof(_CharT) |
435 | + 2 * sizeof(_Rep) - 1); | |
436 | _Rep_alloc_type(__a).deallocate(this, __size / sizeof(_Rep)); | |
872d8fea PC |
437 | } |
438 | ||
439 | template<typename _CharT, typename _Traits, typename _Alloc> | |
440 | _CharT* | |
441 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
442 | _M_clone(const _Alloc& __alloc, size_type __res) | |
443 | { | |
444 | // Requested capacity of the clone. | |
7697e6c6 PC |
445 | const size_type __requested_cap = _M_info._M_length + __res; |
446 | _Rep* __r = _Rep::_S_create(__requested_cap, _M_info._M_capacity, | |
447 | __alloc); | |
872d8fea | 448 | |
7697e6c6 PC |
449 | if (_M_info._M_length) |
450 | _S_copy(__r->_M_refdata(), _M_refdata(), _M_info._M_length); | |
872d8fea | 451 | |
7697e6c6 | 452 | __r->_M_set_length(_M_info._M_length); |
872d8fea PC |
453 | return __r->_M_refdata(); |
454 | } | |
455 | ||
456 | template<typename _CharT, typename _Traits, typename _Alloc> | |
457 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
458 | __rc_string_base(const _Alloc& __a) | |
7697e6c6 | 459 | : _M_dataplus(__a, _S_construct(size_type(), _CharT(), __a)) { } |
872d8fea PC |
460 | |
461 | template<typename _CharT, typename _Traits, typename _Alloc> | |
462 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
463 | __rc_string_base(const __rc_string_base& __rcs) | |
7697e6c6 | 464 | : _M_dataplus(__rcs._M_get_allocator(), |
b6cb8dc2 | 465 | __rcs._M_grab(__rcs._M_get_allocator())) { } |
872d8fea PC |
466 | |
467 | template<typename _CharT, typename _Traits, typename _Alloc> | |
468 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
469 | __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a) | |
7697e6c6 | 470 | : _M_dataplus(__a, _S_construct(__n, __c, __a)) { } |
872d8fea PC |
471 | |
472 | template<typename _CharT, typename _Traits, typename _Alloc> | |
473 | template<typename _InputIterator> | |
474 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
475 | __rc_string_base(_InputIterator __beg, _InputIterator __end, | |
476 | const _Alloc& __a) | |
7697e6c6 | 477 | : _M_dataplus(__a, _S_construct(__beg, __end, __a)) { } |
872d8fea PC |
478 | |
479 | template<typename _CharT, typename _Traits, typename _Alloc> | |
480 | void | |
481 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
482 | _M_leak_hard() | |
483 | { | |
872d8fea | 484 | if (_M_is_shared()) |
cf882919 | 485 | _M_erase(0, 0); |
872d8fea PC |
486 | _M_set_leaked(); |
487 | } | |
488 | ||
489 | // NB: This is the special case for Input Iterators, used in | |
490 | // istreambuf_iterators, etc. | |
491 | // Input Iterators have a cost structure very different from | |
492 | // pointers, calling for a different coding style. | |
493 | template<typename _CharT, typename _Traits, typename _Alloc> | |
494 | template<typename _InIterator> | |
495 | _CharT* | |
496 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
497 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
498 | std::input_iterator_tag) | |
499 | { | |
872d8fea | 500 | if (__beg == __end && __a == _Alloc()) |
7697e6c6 | 501 | return _S_empty_rep._M_refcopy(); |
a5cee480 | 502 | |
872d8fea PC |
503 | // Avoid reallocation for common case. |
504 | _CharT __buf[128]; | |
505 | size_type __len = 0; | |
506 | while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT)) | |
507 | { | |
508 | __buf[__len++] = *__beg; | |
509 | ++__beg; | |
510 | } | |
511 | _Rep* __r = _Rep::_S_create(__len, size_type(0), __a); | |
512 | _S_copy(__r->_M_refdata(), __buf, __len); | |
bc2631e0 | 513 | __try |
872d8fea PC |
514 | { |
515 | while (__beg != __end) | |
516 | { | |
cf882919 | 517 | if (__len == __r->_M_info._M_capacity) |
872d8fea PC |
518 | { |
519 | // Allocate more space. | |
520 | _Rep* __another = _Rep::_S_create(__len + 1, __len, __a); | |
521 | _S_copy(__another->_M_refdata(), __r->_M_refdata(), __len); | |
522 | __r->_M_destroy(__a); | |
523 | __r = __another; | |
524 | } | |
525 | __r->_M_refdata()[__len++] = *__beg; | |
526 | ++__beg; | |
527 | } | |
528 | } | |
bc2631e0 | 529 | __catch(...) |
872d8fea PC |
530 | { |
531 | __r->_M_destroy(__a); | |
532 | __throw_exception_again; | |
533 | } | |
534 | __r->_M_set_length(__len); | |
535 | return __r->_M_refdata(); | |
536 | } | |
537 | ||
538 | template<typename _CharT, typename _Traits, typename _Alloc> | |
b6cb8dc2 | 539 | template<typename _InIterator> |
872d8fea PC |
540 | _CharT* |
541 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
542 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
543 | std::forward_iterator_tag) | |
544 | { | |
872d8fea | 545 | if (__beg == __end && __a == _Alloc()) |
7697e6c6 | 546 | return _S_empty_rep._M_refcopy(); |
a5cee480 | 547 | |
872d8fea | 548 | // NB: Not required, but considered best practice. |
e762c6f4 | 549 | if (__is_null_pointer(__beg) && __beg != __end) |
872d8fea PC |
550 | std::__throw_logic_error(__N("__rc_string_base::" |
551 | "_S_construct NULL not valid")); | |
552 | ||
553 | const size_type __dnew = static_cast<size_type>(std::distance(__beg, | |
554 | __end)); | |
555 | // Check for out_of_range and length_error exceptions. | |
556 | _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a); | |
bc2631e0 | 557 | __try |
872d8fea | 558 | { _S_copy_chars(__r->_M_refdata(), __beg, __end); } |
bc2631e0 | 559 | __catch(...) |
872d8fea PC |
560 | { |
561 | __r->_M_destroy(__a); | |
562 | __throw_exception_again; | |
563 | } | |
564 | __r->_M_set_length(__dnew); | |
565 | return __r->_M_refdata(); | |
566 | } | |
567 | ||
568 | template<typename _CharT, typename _Traits, typename _Alloc> | |
569 | _CharT* | |
570 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
571 | _S_construct(size_type __n, _CharT __c, const _Alloc& __a) | |
572 | { | |
872d8fea | 573 | if (__n == 0 && __a == _Alloc()) |
7697e6c6 | 574 | return _S_empty_rep._M_refcopy(); |
a5cee480 | 575 | |
872d8fea PC |
576 | // Check for out_of_range and length_error exceptions. |
577 | _Rep* __r = _Rep::_S_create(__n, size_type(0), __a); | |
578 | if (__n) | |
579 | _S_assign(__r->_M_refdata(), __n, __c); | |
580 | ||
581 | __r->_M_set_length(__n); | |
582 | return __r->_M_refdata(); | |
583 | } | |
584 | ||
7697e6c6 PC |
585 | template<typename _CharT, typename _Traits, typename _Alloc> |
586 | void | |
587 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
588 | _M_swap(__rc_string_base& __rcs) | |
589 | { | |
590 | if (_M_is_leaked()) | |
591 | _M_set_sharable(); | |
592 | if (__rcs._M_is_leaked()) | |
593 | __rcs._M_set_sharable(); | |
594 | ||
595 | _CharT* __tmp = _M_data(); | |
596 | _M_data(__rcs._M_data()); | |
597 | __rcs._M_data(__tmp); | |
f7ace77f PC |
598 | |
599 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
600 | // 431. Swapping containers with unequal allocators. | |
601 | std::__alloc_swap<allocator_type>::_S_do_it(_M_get_allocator(), | |
602 | __rcs._M_get_allocator()); | |
7697e6c6 PC |
603 | } |
604 | ||
872d8fea PC |
605 | template<typename _CharT, typename _Traits, typename _Alloc> |
606 | void | |
607 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
608 | _M_assign(const __rc_string_base& __rcs) | |
609 | { | |
610 | if (_M_rep() != __rcs._M_rep()) | |
611 | { | |
b6cb8dc2 PC |
612 | _CharT* __tmp = __rcs._M_grab(_M_get_allocator()); |
613 | _M_dispose(); | |
872d8fea PC |
614 | _M_data(__tmp); |
615 | } | |
616 | } | |
617 | ||
618 | template<typename _CharT, typename _Traits, typename _Alloc> | |
619 | void | |
620 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
621 | _M_reserve(size_type __res) | |
622 | { | |
cf882919 PC |
623 | // Make sure we don't shrink below the current size. |
624 | if (__res < _M_length()) | |
625 | __res = _M_length(); | |
626 | ||
872d8fea PC |
627 | if (__res != _M_capacity() || _M_is_shared()) |
628 | { | |
b6cb8dc2 PC |
629 | _CharT* __tmp = _M_rep()->_M_clone(_M_get_allocator(), |
630 | __res - _M_length()); | |
631 | _M_dispose(); | |
872d8fea PC |
632 | _M_data(__tmp); |
633 | } | |
634 | } | |
635 | ||
636 | template<typename _CharT, typename _Traits, typename _Alloc> | |
637 | void | |
638 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
cf882919 PC |
639 | _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, |
640 | size_type __len2) | |
872d8fea | 641 | { |
cf882919 PC |
642 | const size_type __how_much = _M_length() - __pos - __len1; |
643 | ||
644 | _Rep* __r = _Rep::_S_create(_M_length() + __len2 - __len1, | |
645 | _M_capacity(), _M_get_allocator()); | |
872d8fea | 646 | |
cf882919 PC |
647 | if (__pos) |
648 | _S_copy(__r->_M_refdata(), _M_data(), __pos); | |
649 | if (__s && __len2) | |
650 | _S_copy(__r->_M_refdata() + __pos, __s, __len2); | |
651 | if (__how_much) | |
652 | _S_copy(__r->_M_refdata() + __pos + __len2, | |
653 | _M_data() + __pos + __len1, __how_much); | |
654 | ||
655 | _M_dispose(); | |
656 | _M_data(__r->_M_refdata()); | |
657 | } | |
658 | ||
659 | template<typename _CharT, typename _Traits, typename _Alloc> | |
660 | void | |
661 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
662 | _M_erase(size_type __pos, size_type __n) | |
663 | { | |
664 | const size_type __new_size = _M_length() - __n; | |
665 | const size_type __how_much = _M_length() - __pos - __n; | |
666 | ||
667 | if (_M_is_shared()) | |
872d8fea PC |
668 | { |
669 | // Must reallocate. | |
b6cb8dc2 PC |
670 | _Rep* __r = _Rep::_S_create(__new_size, _M_capacity(), |
671 | _M_get_allocator()); | |
872d8fea PC |
672 | |
673 | if (__pos) | |
674 | _S_copy(__r->_M_refdata(), _M_data(), __pos); | |
675 | if (__how_much) | |
cf882919 PC |
676 | _S_copy(__r->_M_refdata() + __pos, |
677 | _M_data() + __pos + __n, __how_much); | |
872d8fea | 678 | |
b6cb8dc2 | 679 | _M_dispose(); |
872d8fea PC |
680 | _M_data(__r->_M_refdata()); |
681 | } | |
cf882919 | 682 | else if (__how_much && __n) |
872d8fea PC |
683 | { |
684 | // Work in-place. | |
cf882919 PC |
685 | _S_move(_M_data() + __pos, |
686 | _M_data() + __pos + __n, __how_much); | |
872d8fea | 687 | } |
cf882919 PC |
688 | |
689 | _M_rep()->_M_set_length(__new_size); | |
872d8fea | 690 | } |
b6105bf2 PC |
691 | |
692 | template<> | |
693 | inline bool | |
694 | __rc_string_base<char, std::char_traits<char>, | |
695 | std::allocator<char> >:: | |
696 | _M_compare(const __rc_string_base& __rcs) const | |
697 | { | |
698 | if (_M_rep() == __rcs._M_rep()) | |
699 | return true; | |
700 | return false; | |
701 | } | |
702 | ||
1c846af9 | 703 | #ifdef _GLIBCXX_USE_WCHAR_T |
b6105bf2 PC |
704 | template<> |
705 | inline bool | |
706 | __rc_string_base<wchar_t, std::char_traits<wchar_t>, | |
707 | std::allocator<wchar_t> >:: | |
708 | _M_compare(const __rc_string_base& __rcs) const | |
709 | { | |
710 | if (_M_rep() == __rcs._M_rep()) | |
711 | return true; | |
712 | return false; | |
713 | } | |
1c846af9 | 714 | #endif |
3cbc7af0 BK |
715 | |
716 | _GLIBCXX_END_NAMESPACE | |
872d8fea PC |
717 | |
718 | #endif /* _RC_STRING_BASE_H */ |