williamr@4: /*
williamr@4:  * Copyright (c) 1997-1999
williamr@4:  * Silicon Graphics Computer Systems, Inc.
williamr@4:  *
williamr@4:  * Copyright (c) 1999
williamr@4:  * Boris Fomitchev
williamr@4:  *
williamr@4:  * Copyright (c) 2003
williamr@4:  * Francois Dumont
williamr@4:  *
williamr@4:  * This material is provided "as is", with absolutely no warranty expressed
williamr@4:  * or implied. Any use is at your own risk.
williamr@4:  *
williamr@4:  * Permission to use or copy this software for any purpose is hereby granted
williamr@4:  * without fee, provided the above notices are retained on all copies.
williamr@4:  * Permission to modify the code and to distribute modified code is granted,
williamr@4:  * provided the above notices are retained, and a notice that the code was
williamr@4:  * modified is included with the above copyright notice.
williamr@4:  *
williamr@4:  */
williamr@4: 
williamr@4: #ifndef _STLP_STRING_BASE_H
williamr@4: #define _STLP_STRING_BASE_H
williamr@4: 
williamr@4: // ------------------------------------------------------------
williamr@4: // Class _String_base.
williamr@4: 
williamr@4: // _String_base is a helper class that makes it it easier to write an
williamr@4: // exception-safe version of basic_string.  The constructor allocates,
williamr@4: // but does not initialize, a block of memory.  The destructor
williamr@4: // deallocates, but does not destroy elements within, a block of
williamr@4: // memory.  The destructor assumes that _M_start either is null, or else
williamr@4: // points to a block of memory that was allocated using _String_base's
williamr@4: // allocator and whose size is _M_end_of_storage._M_data - _M_start.
williamr@4: 
williamr@4: _STLP_BEGIN_NAMESPACE
williamr@4: 
williamr@4: _STLP_MOVE_TO_PRIV_NAMESPACE
williamr@4: 
williamr@4: #ifndef _STLP_SHORT_STRING_SZ
williamr@4: #  define _STLP_SHORT_STRING_SZ 16
williamr@4: #endif
williamr@4: 
williamr@4: template <class _Tp, class _Alloc>
williamr@4: class _String_base {
williamr@4:   typedef _String_base<_Tp, _Alloc> _Self;
williamr@4: protected:
williamr@4:   _STLP_FORCE_ALLOCATORS(_Tp, _Alloc)
williamr@4: public:
williamr@4:   //dums: Some compiler(MSVC6) require it to be public not simply protected!
williamr@4:   enum {_DEFAULT_SIZE = _STLP_SHORT_STRING_SZ};
williamr@4:   //This is needed by the full move framework
williamr@4:   typedef typename _Alloc_traits<_Tp, _Alloc>::allocator_type allocator_type;
williamr@4:   typedef _STLP_alloc_proxy<_Tp*, _Tp, allocator_type> _AllocProxy;
williamr@4:   typedef size_t size_type;
williamr@4: private:
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:   union _Buffers {
williamr@4:     _Tp*  _M_dynamic_buf;
williamr@4:     _Tp   _M_static_buf[_DEFAULT_SIZE];
williamr@4:   } _M_buffers;
williamr@4: #else
williamr@4:   _Tp*    _M_start;
williamr@4: #endif /* _STLP_USE_SHORT_STRING_OPTIM */
williamr@4: protected:
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:   bool _M_using_static_buf() const {
williamr@4:     return (_M_end_of_storage._M_data == _M_buffers._M_static_buf + _DEFAULT_SIZE);
williamr@4:   }
williamr@4:   _Tp const* _M_Start() const {
williamr@4:     return _M_using_static_buf()?_M_buffers._M_static_buf:_M_buffers._M_dynamic_buf;
williamr@4:   }
williamr@4:   _Tp* _M_Start() {
williamr@4:     return _M_using_static_buf()?_M_buffers._M_static_buf:_M_buffers._M_dynamic_buf;
williamr@4:   }
williamr@4: #else
williamr@4:   _Tp const* _M_Start() const {return _M_start;}
williamr@4:   _Tp* _M_Start() {return _M_start;}
williamr@4: #endif /* _STLP_USE_SHORT_STRING_OPTIM */
williamr@4: 
williamr@4:   _Tp*    _M_finish;
williamr@4:   _AllocProxy _M_end_of_storage;
williamr@4: 
williamr@4:   _Tp const* _M_Finish() const {return _M_finish;}
williamr@4:   _Tp* _M_Finish() {return _M_finish;}
williamr@4: 
williamr@4:   // Precondition: 0 < __n <= max_size().
williamr@4:   void _M_allocate_block(size_t __n = _DEFAULT_SIZE);
williamr@4:   void _M_deallocate_block() {
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     if (!_M_using_static_buf() && (_M_buffers._M_dynamic_buf != 0))
williamr@4:       _M_end_of_storage.deallocate(_M_buffers._M_dynamic_buf, _M_end_of_storage._M_data - _M_buffers._M_dynamic_buf);
williamr@4: #else
williamr@4:     if (_M_start != 0)
williamr@4:       _M_end_of_storage.deallocate(_M_start, _M_end_of_storage._M_data - _M_start);
williamr@4: #endif /* _STLP_USE_SHORT_STRING_OPTIM */
williamr@4:   }
williamr@4: 
williamr@4:   size_t max_size() const {
williamr@4:     const size_type __string_max_size = size_type(-1) / sizeof(_Tp);
williamr@4:     typename allocator_type::size_type __alloc_max_size = _M_end_of_storage.max_size();
williamr@4:     return (min)(__alloc_max_size, __string_max_size) - 1;
williamr@4:   }
williamr@4: 
williamr@4:   _String_base(const allocator_type& __a)
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     : _M_finish(_M_buffers._M_static_buf), _M_end_of_storage(__a, _M_buffers._M_static_buf + _DEFAULT_SIZE)
williamr@4: #else
williamr@4:     : _M_start(0), _M_finish(0), _M_end_of_storage(__a, (_Tp*)0)
williamr@4: #endif
williamr@4:     {}
williamr@4: 
williamr@4:   _String_base(const allocator_type& __a, size_t __n)
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     : _M_finish(_M_buffers._M_static_buf), _M_end_of_storage(__a, _M_buffers._M_static_buf + _DEFAULT_SIZE) {
williamr@4: #else
williamr@4:     : _M_start(0), _M_finish(0), _M_end_of_storage(__a, (_Tp*)0) {
williamr@4: #endif
williamr@4:       _M_allocate_block(__n);
williamr@4:     }
williamr@4: 
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:   void _M_move_src (_Self &src) {
williamr@4:       if (src._M_using_static_buf()) {
williamr@4:         _M_buffers = src._M_buffers;
williamr@4:         _M_finish = _M_buffers._M_static_buf + (src._M_finish - src._M_buffers._M_static_buf);
williamr@4:         _M_end_of_storage._M_data = _M_buffers._M_static_buf + _DEFAULT_SIZE;
williamr@4:       }
williamr@4:       else {
williamr@4:         _M_buffers._M_dynamic_buf = src._M_buffers._M_dynamic_buf;
williamr@4:         _M_finish = src._M_finish;
williamr@4:         _M_end_of_storage._M_data = src._M_end_of_storage._M_data;
williamr@4:         src._M_buffers._M_dynamic_buf = 0;
williamr@4:       }
williamr@4:     }
williamr@4: #endif
williamr@4: 
williamr@4:   _String_base(__move_source<_Self> src)
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     : _M_end_of_storage(__move_source<_AllocProxy>(src.get()._M_end_of_storage)) {
williamr@4:       _M_move_src(src.get());
williamr@4: #else
williamr@4:     : _M_start(src.get()._M_start), _M_finish(src.get()._M_finish),
williamr@4:       _M_end_of_storage(__move_source<_AllocProxy>(src.get()._M_end_of_storage)) {
williamr@4:       src.get()._M_start = 0;
williamr@4: #endif
williamr@4:     }
williamr@4: 
williamr@4:   ~_String_base() { _M_deallocate_block(); }
williamr@4: 
williamr@4:   void _M_reset(_Tp *__start, _Tp *__finish, _Tp *__end_of_storage) {
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     _M_buffers._M_dynamic_buf = __start;
williamr@4: #else
williamr@4:     _M_start = __start;
williamr@4: #endif
williamr@4:     _M_finish = __finish;
williamr@4:     _M_end_of_storage._M_data = __end_of_storage;
williamr@4:   }
williamr@4: 
williamr@4:   void _M_destroy_back () {
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     if (!_M_using_static_buf())
williamr@4: #endif /* _STLP_USE_SHORT_STRING_OPTIM */
williamr@4:       _STLP_STD::_Destroy(_M_finish);
williamr@4:   }
williamr@4: 
williamr@4:   void _M_destroy_range(size_t __from_off = 0, size_t __to_off = 1) {
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     if (!_M_using_static_buf())
williamr@4:       _STLP_STD::_Destroy_Range(_M_buffers._M_dynamic_buf + __from_off, _M_finish + __to_off);
williamr@4: #else
williamr@4:     _STLP_STD::_Destroy_Range(_M_start + __from_off, _M_finish + __to_off);
williamr@4: #endif /* _STLP_USE_SHORT_STRING_OPTIM */
williamr@4:   }
williamr@4: 
williamr@4:   void _M_destroy_ptr_range(_Tp *__f, _Tp *__l) {
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     if (!_M_using_static_buf())
williamr@4: #endif /* _STLP_USE_SHORT_STRING_OPTIM */
williamr@4:       _STLP_STD::_Destroy_Range(__f, __l);
williamr@4:   }
williamr@4: 
williamr@4:   void _M_Swap(_Self &__s) {
williamr@4: #if defined (_STLP_USE_SHORT_STRING_OPTIM)
williamr@4:     if (_M_using_static_buf()) {
williamr@4:       if (__s._M_using_static_buf()) {
williamr@4:         _STLP_STD::swap(_M_buffers, __s._M_buffers);
williamr@4:         _Tp *__tmp = _M_finish;
williamr@4:         _M_finish = _M_buffers._M_static_buf + (__s._M_finish - __s._M_buffers._M_static_buf);
williamr@4:         __s._M_finish = __s._M_buffers._M_static_buf + (__tmp - _M_buffers._M_static_buf);
williamr@4:         //We need to swap _M_end_of_storage for allocators with state:
williamr@4:         _M_end_of_storage.swap(__s._M_end_of_storage);
williamr@4:         _M_end_of_storage._M_data = _M_buffers._M_static_buf + _DEFAULT_SIZE;
williamr@4:         __s._M_end_of_storage._M_data = __s._M_buffers._M_static_buf + _DEFAULT_SIZE;
williamr@4:       } else {
williamr@4:         __s._M_Swap(*this);
williamr@4:         return;
williamr@4:       }
williamr@4:     }
williamr@4:     else if (__s._M_using_static_buf()) {
williamr@4:       _Tp *__tmp = _M_buffers._M_dynamic_buf;
williamr@4:       _Tp *__tmp_finish = _M_finish;
williamr@4:       _Tp *__tmp_end_data = _M_end_of_storage._M_data;
williamr@4:       _M_buffers = __s._M_buffers;
williamr@4:       //We need to swap _M_end_of_storage for allocators with state:
williamr@4:       _M_end_of_storage.swap(__s._M_end_of_storage);
williamr@4:       _M_end_of_storage._M_data = _M_buffers._M_static_buf + _DEFAULT_SIZE;
williamr@4:       _M_finish = _M_buffers._M_static_buf + (__s._M_finish - __s._M_buffers._M_static_buf);
williamr@4:       __s._M_buffers._M_dynamic_buf = __tmp;
williamr@4:       __s._M_end_of_storage._M_data = __tmp_end_data;
williamr@4:       __s._M_finish = __tmp_finish;
williamr@4:     }
williamr@4:     else {
williamr@4:       _STLP_STD::swap(_M_buffers._M_dynamic_buf, __s._M_buffers._M_dynamic_buf);
williamr@4:       _M_end_of_storage.swap(__s._M_end_of_storage);
williamr@4:       _STLP_STD::swap(_M_finish, __s._M_finish);
williamr@4:     }
williamr@4: #else
williamr@4:     _STLP_STD::swap(_M_start, __s._M_start);
williamr@4:     _M_end_of_storage.swap(__s._M_end_of_storage);
williamr@4:     _STLP_STD::swap(_M_finish, __s._M_finish);
williamr@4: #endif /* _STLP_USE_SHORT_STRING_OPTIM */
williamr@4:   }
williamr@4: 
williamr@4:   void _STLP_FUNCTION_THROWS _M_throw_length_error() const;
williamr@4:   void _STLP_FUNCTION_THROWS _M_throw_out_of_range() const;
williamr@4: };
williamr@4: 
williamr@4: #undef _STLP_SHORT_STRING_SZ
williamr@4: 
williamr@4: #if defined (_STLP_USE_TEMPLATE_EXPORT)
williamr@4: _STLP_EXPORT_TEMPLATE_CLASS _String_base<char, allocator<char> >;
williamr@4: #  if defined (_STLP_HAS_WCHAR_T)
williamr@4: _STLP_EXPORT_TEMPLATE_CLASS _String_base<wchar_t, allocator<wchar_t> >;
williamr@4: #  endif
williamr@4: #endif /* _STLP_USE_TEMPLATE_EXPORT */
williamr@4: 
williamr@4: _STLP_MOVE_TO_STD_NAMESPACE
williamr@4: 
williamr@4: _STLP_END_NAMESPACE
williamr@4: 
williamr@4: #endif /* _STLP_STRING_BASE_H */
williamr@4: 
williamr@4: /*
williamr@4:  * Local Variables:
williamr@4:  * mode:C++
williamr@4:  * End:
williamr@4:  */