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// Short-string-optimized versatile string base -*- C++ -*-

// Copyright (C) 2005-2015 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

// .

/** @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

    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

        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

        void

        _M_construct_aux(_Integer __beg, _Integer __end, std::__true_type)

	{ _M_construct_aux_2(static_cast(__beg), __end); }

      void

      _M_construct_aux_2(size_type __req, _CharT __c)

      { _M_construct(__req, __c); }

      template

        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

        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

        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

        __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

    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

    _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

    __sso_string_base<_CharT, _Traits, _Alloc>::

    __sso_string_base(const _Alloc& __a)

    : _M_dataplus(__a, _M_local_data)

    { _M_set_length(0); }

  template

    __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

    __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

    __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

    template

    __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

    template

      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

    template

      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(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

    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

    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

    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

    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

    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 */