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Editing: sso_string_base.h
// Short-string-optimized versatile string base -*- C++ -*- // Copyright (C) 2005-2018 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file ext/sso_string_base.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{ext/vstring.h} */ #ifndef _SSO_STRING_BASE_H #define _SSO_STRING_BASE_H 1 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _CharT, typename _Traits, typename _Alloc> class __sso_string_base : protected __vstring_utility<_CharT, _Traits, _Alloc> { public: typedef _Traits traits_type; typedef typename _Traits::char_type value_type; typedef __vstring_utility<_CharT, _Traits, _Alloc> _Util_Base; typedef typename _Util_Base::_CharT_alloc_type _CharT_alloc_type; typedef typename _CharT_alloc_type::size_type size_type; private: // Data Members: typename _Util_Base::template _Alloc_hider<_CharT_alloc_type> _M_dataplus; size_type _M_string_length; enum { _S_local_capacity = 15 }; union { _CharT _M_local_data[_S_local_capacity + 1]; size_type _M_allocated_capacity; }; void _M_data(_CharT* __p) { _M_dataplus._M_p = __p; } void _M_length(size_type __length) { _M_string_length = __length; } void _M_capacity(size_type __capacity) { _M_allocated_capacity = __capacity; } bool _M_is_local() const { return _M_data() == _M_local_data; } // Create & Destroy _CharT* _M_create(size_type&, size_type); void _M_dispose() { if (!_M_is_local()) _M_destroy(_M_allocated_capacity); } void _M_destroy(size_type __size) throw() { _M_get_allocator().deallocate(_M_data(), __size + 1); } // _M_construct_aux is used to implement the 21.3.1 para 15 which // requires special behaviour if _InIterator is an integral type template<typename _InIterator> void _M_construct_aux(_InIterator __beg, _InIterator __end, std::__false_type) { typedef typename iterator_traits<_InIterator>::iterator_category _Tag; _M_construct(__beg, __end, _Tag()); } // _GLIBCXX_RESOLVE_LIB_DEFECTS // 438. Ambiguity in the "do the right thing" clause template<typename _Integer> void _M_construct_aux(_Integer __beg, _Integer __end, std::__true_type) { _M_construct_aux_2(static_cast<size_type>(__beg), __end); } void _M_construct_aux_2(size_type __req, _CharT __c) { _M_construct(__req, __c); } template<typename _InIterator> void _M_construct(_InIterator __beg, _InIterator __end) { typedef typename std::__is_integer<_InIterator>::__type _Integral; _M_construct_aux(__beg, __end, _Integral()); } // For Input Iterators, used in istreambuf_iterators, etc. template<typename _InIterator> void _M_construct(_InIterator __beg, _InIterator __end, std::input_iterator_tag); // For forward_iterators up to random_access_iterators, used for // string::iterator, _CharT*, etc. template<typename _FwdIterator> void _M_construct(_FwdIterator __beg, _FwdIterator __end, std::forward_iterator_tag); void _M_construct(size_type __req, _CharT __c); public: size_type _M_max_size() const { return (_M_get_allocator().max_size() - 1) / 2; } _CharT* _M_data() const { return _M_dataplus._M_p; } size_type _M_length() const { return _M_string_length; } size_type _M_capacity() const { return _M_is_local() ? size_type(_S_local_capacity) : _M_allocated_capacity; } bool _M_is_shared() const { return false; } void _M_set_leaked() { } void _M_leak() { } void _M_set_length(size_type __n) { _M_length(__n); traits_type::assign(_M_data()[__n], _CharT()); } __sso_string_base() : _M_dataplus(_M_local_data) { _M_set_length(0); } __sso_string_base(const _Alloc& __a); __sso_string_base(const __sso_string_base& __rcs); #if __cplusplus >= 201103L __sso_string_base(__sso_string_base&& __rcs); #endif __sso_string_base(size_type __n, _CharT __c, const _Alloc& __a); template<typename _InputIterator> __sso_string_base(_InputIterator __beg, _InputIterator __end, const _Alloc& __a); ~__sso_string_base() { _M_dispose(); } _CharT_alloc_type& _M_get_allocator() { return _M_dataplus; } const _CharT_alloc_type& _M_get_allocator() const { return _M_dataplus; } void _M_swap(__sso_string_base& __rcs); void _M_assign(const __sso_string_base& __rcs); void _M_reserve(size_type __res); void _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, size_type __len2); void _M_erase(size_type __pos, size_type __n); void _M_clear() { _M_set_length(0); } bool _M_compare(const __sso_string_base&) const { return false; } }; template<typename _CharT, typename _Traits, typename _Alloc> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_swap(__sso_string_base& __rcs) { if (this == &__rcs) return; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 431. Swapping containers with unequal allocators. std::__alloc_swap<_CharT_alloc_type>::_S_do_it(_M_get_allocator(), __rcs._M_get_allocator()); if (_M_is_local()) if (__rcs._M_is_local()) { if (_M_length() && __rcs._M_length()) { _CharT __tmp_data[_S_local_capacity + 1]; traits_type::copy(__tmp_data, __rcs._M_local_data, _S_local_capacity + 1); traits_type::copy(__rcs._M_local_data, _M_local_data, _S_local_capacity + 1); traits_type::copy(_M_local_data, __tmp_data, _S_local_capacity + 1); } else if (__rcs._M_length()) { traits_type::copy(_M_local_data, __rcs._M_local_data, _S_local_capacity + 1); _M_length(__rcs._M_length()); __rcs._M_set_length(0); return; } else if (_M_length()) { traits_type::copy(__rcs._M_local_data, _M_local_data, _S_local_capacity + 1); __rcs._M_length(_M_length()); _M_set_length(0); return; } } else { const size_type __tmp_capacity = __rcs._M_allocated_capacity; traits_type::copy(__rcs._M_local_data, _M_local_data, _S_local_capacity + 1); _M_data(__rcs._M_data()); __rcs._M_data(__rcs._M_local_data); _M_capacity(__tmp_capacity); } else { const size_type __tmp_capacity = _M_allocated_capacity; if (__rcs._M_is_local()) { traits_type::copy(_M_local_data, __rcs._M_local_data, _S_local_capacity + 1); __rcs._M_data(_M_data()); _M_data(_M_local_data); } else { _CharT* __tmp_ptr = _M_data(); _M_data(__rcs._M_data()); __rcs._M_data(__tmp_ptr); _M_capacity(__rcs._M_allocated_capacity); } __rcs._M_capacity(__tmp_capacity); } const size_type __tmp_length = _M_length(); _M_length(__rcs._M_length()); __rcs._M_length(__tmp_length); } template<typename _CharT, typename _Traits, typename _Alloc> _CharT* __sso_string_base<_CharT, _Traits, _Alloc>:: _M_create(size_type& __capacity, size_type __old_capacity) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // 83. String::npos vs. string::max_size() if (__capacity > _M_max_size()) std::__throw_length_error(__N("__sso_string_base::_M_create")); // The below implements an exponential growth policy, necessary to // meet amortized linear time requirements of the library: see // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) { __capacity = 2 * __old_capacity; // Never allocate a string bigger than max_size. if (__capacity > _M_max_size()) __capacity = _M_max_size(); } // NB: Need an array of char_type[__capacity], plus a terminating // null char_type() element. return _M_get_allocator().allocate(__capacity + 1); } template<typename _CharT, typename _Traits, typename _Alloc> __sso_string_base<_CharT, _Traits, _Alloc>:: __sso_string_base(const _Alloc& __a) : _M_dataplus(__a, _M_local_data) { _M_set_length(0); } template<typename _CharT, typename _Traits, typename _Alloc> __sso_string_base<_CharT, _Traits, _Alloc>:: __sso_string_base(const __sso_string_base& __rcs) : _M_dataplus(__rcs._M_get_allocator(), _M_local_data) { _M_construct(__rcs._M_data(), __rcs._M_data() + __rcs._M_length()); } #if __cplusplus >= 201103L template<typename _CharT, typename _Traits, typename _Alloc> __sso_string_base<_CharT, _Traits, _Alloc>:: __sso_string_base(__sso_string_base&& __rcs) : _M_dataplus(__rcs._M_get_allocator(), _M_local_data) { if (__rcs._M_is_local()) { if (__rcs._M_length()) traits_type::copy(_M_local_data, __rcs._M_local_data, _S_local_capacity + 1); } else { _M_data(__rcs._M_data()); _M_capacity(__rcs._M_allocated_capacity); } _M_set_length(__rcs._M_length()); __rcs._M_data(__rcs._M_local_data); __rcs._M_set_length(0); } #endif template<typename _CharT, typename _Traits, typename _Alloc> __sso_string_base<_CharT, _Traits, _Alloc>:: __sso_string_base(size_type __n, _CharT __c, const _Alloc& __a) : _M_dataplus(__a, _M_local_data) { _M_construct(__n, __c); } template<typename _CharT, typename _Traits, typename _Alloc> template<typename _InputIterator> __sso_string_base<_CharT, _Traits, _Alloc>:: __sso_string_base(_InputIterator __beg, _InputIterator __end, const _Alloc& __a) : _M_dataplus(__a, _M_local_data) { _M_construct(__beg, __end); } // NB: This is the special case for Input Iterators, used in // istreambuf_iterators, etc. // Input Iterators have a cost structure very different from // pointers, calling for a different coding style. template<typename _CharT, typename _Traits, typename _Alloc> template<typename _InIterator> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_construct(_InIterator __beg, _InIterator __end, std::input_iterator_tag) { size_type __len = 0; size_type __capacity = size_type(_S_local_capacity); while (__beg != __end && __len < __capacity) { _M_data()[__len++] = *__beg; ++__beg; } __try { while (__beg != __end) { if (__len == __capacity) { // Allocate more space. __capacity = __len + 1; _CharT* __another = _M_create(__capacity, __len); this->_S_copy(__another, _M_data(), __len); _M_dispose(); _M_data(__another); _M_capacity(__capacity); } _M_data()[__len++] = *__beg; ++__beg; } } __catch(...) { _M_dispose(); __throw_exception_again; } _M_set_length(__len); } template<typename _CharT, typename _Traits, typename _Alloc> template<typename _InIterator> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_construct(_InIterator __beg, _InIterator __end, std::forward_iterator_tag) { // NB: Not required, but considered best practice. if (__is_null_pointer(__beg) && __beg != __end) std::__throw_logic_error(__N("__sso_string_base::" "_M_construct null not valid")); size_type __dnew = static_cast<size_type>(std::distance(__beg, __end)); if (__dnew > size_type(_S_local_capacity)) { _M_data(_M_create(__dnew, size_type(0))); _M_capacity(__dnew); } // Check for out_of_range and length_error exceptions. __try { this->_S_copy_chars(_M_data(), __beg, __end); } __catch(...) { _M_dispose(); __throw_exception_again; } _M_set_length(__dnew); } template<typename _CharT, typename _Traits, typename _Alloc> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_construct(size_type __n, _CharT __c) { if (__n > size_type(_S_local_capacity)) { _M_data(_M_create(__n, size_type(0))); _M_capacity(__n); } if (__n) this->_S_assign(_M_data(), __n, __c); _M_set_length(__n); } template<typename _CharT, typename _Traits, typename _Alloc> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_assign(const __sso_string_base& __rcs) { if (this != &__rcs) { const size_type __rsize = __rcs._M_length(); const size_type __capacity = _M_capacity(); if (__rsize > __capacity) { size_type __new_capacity = __rsize; _CharT* __tmp = _M_create(__new_capacity, __capacity); _M_dispose(); _M_data(__tmp); _M_capacity(__new_capacity); } if (__rsize) this->_S_copy(_M_data(), __rcs._M_data(), __rsize); _M_set_length(__rsize); } } template<typename _CharT, typename _Traits, typename _Alloc> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_reserve(size_type __res) { // Make sure we don't shrink below the current size. if (__res < _M_length()) __res = _M_length(); const size_type __capacity = _M_capacity(); if (__res != __capacity) { if (__res > __capacity || __res > size_type(_S_local_capacity)) { _CharT* __tmp = _M_create(__res, __capacity); this->_S_copy(__tmp, _M_data(), _M_length() + 1); _M_dispose(); _M_data(__tmp); _M_capacity(__res); } else if (!_M_is_local()) { this->_S_copy(_M_local_data, _M_data(), _M_length() + 1); _M_destroy(__capacity); _M_data(_M_local_data); } } } template<typename _CharT, typename _Traits, typename _Alloc> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, size_type __len2) { const size_type __how_much = _M_length() - __pos - __len1; size_type __new_capacity = _M_length() + __len2 - __len1; _CharT* __r = _M_create(__new_capacity, _M_capacity()); if (__pos) this->_S_copy(__r, _M_data(), __pos); if (__s && __len2) this->_S_copy(__r + __pos, __s, __len2); if (__how_much) this->_S_copy(__r + __pos + __len2, _M_data() + __pos + __len1, __how_much); _M_dispose(); _M_data(__r); _M_capacity(__new_capacity); } template<typename _CharT, typename _Traits, typename _Alloc> void __sso_string_base<_CharT, _Traits, _Alloc>:: _M_erase(size_type __pos, size_type __n) { const size_type __how_much = _M_length() - __pos - __n; if (__how_much && __n) this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much); _M_set_length(_M_length() - __n); } _GLIBCXX_END_NAMESPACE_VERSION } // namespace #endif /* _SSO_STRING_BASE_H */
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