mirror of git://gcc.gnu.org/git/gcc.git
274 lines
8.2 KiB
C++
274 lines
8.2 KiB
C++
// Temporary buffer implementation -*- C++ -*-
|
|
|
|
// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
|
|
// 2010, 2011, 2012
|
|
// 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/>.
|
|
|
|
/*
|
|
*
|
|
* Copyright (c) 1994
|
|
* Hewlett-Packard Company
|
|
*
|
|
* Permission to use, copy, modify, distribute and sell this software
|
|
* and its documentation for any purpose is hereby granted without fee,
|
|
* provided that the above copyright notice appear in all copies and
|
|
* that both that copyright notice and this permission notice appear
|
|
* in supporting documentation. Hewlett-Packard Company makes no
|
|
* representations about the suitability of this software for any
|
|
* purpose. It is provided "as is" without express or implied warranty.
|
|
*
|
|
*
|
|
* Copyright (c) 1996,1997
|
|
* Silicon Graphics Computer Systems, Inc.
|
|
*
|
|
* Permission to use, copy, modify, distribute and sell this software
|
|
* and its documentation for any purpose is hereby granted without fee,
|
|
* provided that the above copyright notice appear in all copies and
|
|
* that both that copyright notice and this permission notice appear
|
|
* in supporting documentation. Silicon Graphics makes no
|
|
* representations about the suitability of this software for any
|
|
* purpose. It is provided "as is" without express or implied warranty.
|
|
*/
|
|
|
|
/** @file bits/stl_tempbuf.h
|
|
* This is an internal header file, included by other library headers.
|
|
* Do not attempt to use it directly. @headername{memory}
|
|
*/
|
|
|
|
#ifndef _STL_TEMPBUF_H
|
|
#define _STL_TEMPBUF_H 1
|
|
|
|
#include <bits/stl_algobase.h>
|
|
#include <bits/stl_construct.h>
|
|
|
|
namespace std _GLIBCXX_VISIBILITY(default)
|
|
{
|
|
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|
|
|
/**
|
|
* @brief Allocates a temporary buffer.
|
|
* @param __len The number of objects of type Tp.
|
|
* @return See full description.
|
|
*
|
|
* Reinventing the wheel, but this time with prettier spokes!
|
|
*
|
|
* This function tries to obtain storage for @c __len adjacent Tp
|
|
* objects. The objects themselves are not constructed, of course.
|
|
* A pair<> is returned containing <em>the buffer s address and
|
|
* capacity (in the units of sizeof(_Tp)), or a pair of 0 values if
|
|
* no storage can be obtained.</em> Note that the capacity obtained
|
|
* may be less than that requested if the memory is unavailable;
|
|
* you should compare len with the .second return value.
|
|
*
|
|
* Provides the nothrow exception guarantee.
|
|
*/
|
|
template<typename _Tp>
|
|
pair<_Tp*, ptrdiff_t>
|
|
get_temporary_buffer(ptrdiff_t __len) _GLIBCXX_NOEXCEPT
|
|
{
|
|
const ptrdiff_t __max =
|
|
__gnu_cxx::__numeric_traits<ptrdiff_t>::__max / sizeof(_Tp);
|
|
if (__len > __max)
|
|
__len = __max;
|
|
|
|
while (__len > 0)
|
|
{
|
|
_Tp* __tmp = static_cast<_Tp*>(::operator new(__len * sizeof(_Tp),
|
|
std::nothrow));
|
|
if (__tmp != 0)
|
|
return std::pair<_Tp*, ptrdiff_t>(__tmp, __len);
|
|
__len /= 2;
|
|
}
|
|
return std::pair<_Tp*, ptrdiff_t>(static_cast<_Tp*>(0), 0);
|
|
}
|
|
|
|
/**
|
|
* @brief The companion to get_temporary_buffer().
|
|
* @param __p A buffer previously allocated by get_temporary_buffer.
|
|
* @return None.
|
|
*
|
|
* Frees the memory pointed to by __p.
|
|
*/
|
|
template<typename _Tp>
|
|
inline void
|
|
return_temporary_buffer(_Tp* __p)
|
|
{ ::operator delete(__p, std::nothrow); }
|
|
|
|
|
|
/**
|
|
* This class is used in two places: stl_algo.h and ext/memory,
|
|
* where it is wrapped as the temporary_buffer class. See
|
|
* temporary_buffer docs for more notes.
|
|
*/
|
|
template<typename _ForwardIterator, typename _Tp>
|
|
class _Temporary_buffer
|
|
{
|
|
// concept requirements
|
|
__glibcxx_class_requires(_ForwardIterator, _ForwardIteratorConcept)
|
|
|
|
public:
|
|
typedef _Tp value_type;
|
|
typedef value_type* pointer;
|
|
typedef pointer iterator;
|
|
typedef ptrdiff_t size_type;
|
|
|
|
protected:
|
|
size_type _M_original_len;
|
|
size_type _M_len;
|
|
pointer _M_buffer;
|
|
|
|
public:
|
|
/// As per Table mumble.
|
|
size_type
|
|
size() const
|
|
{ return _M_len; }
|
|
|
|
/// Returns the size requested by the constructor; may be >size().
|
|
size_type
|
|
requested_size() const
|
|
{ return _M_original_len; }
|
|
|
|
/// As per Table mumble.
|
|
iterator
|
|
begin()
|
|
{ return _M_buffer; }
|
|
|
|
/// As per Table mumble.
|
|
iterator
|
|
end()
|
|
{ return _M_buffer + _M_len; }
|
|
|
|
/**
|
|
* Constructs a temporary buffer of a size somewhere between
|
|
* zero and the size of the given range.
|
|
*/
|
|
_Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last);
|
|
|
|
~_Temporary_buffer()
|
|
{
|
|
std::_Destroy(_M_buffer, _M_buffer + _M_len);
|
|
std::return_temporary_buffer(_M_buffer);
|
|
}
|
|
|
|
private:
|
|
// Disable copy constructor and assignment operator.
|
|
_Temporary_buffer(const _Temporary_buffer&);
|
|
|
|
void
|
|
operator=(const _Temporary_buffer&);
|
|
};
|
|
|
|
|
|
template<bool>
|
|
struct __uninitialized_construct_buf_dispatch
|
|
{
|
|
template<typename _Pointer, typename _ForwardIterator>
|
|
static void
|
|
__ucr(_Pointer __first, _Pointer __last,
|
|
_ForwardIterator __seed)
|
|
{
|
|
if(__first == __last)
|
|
return;
|
|
|
|
_Pointer __cur = __first;
|
|
__try
|
|
{
|
|
std::_Construct(std::__addressof(*__first),
|
|
_GLIBCXX_MOVE(*__seed));
|
|
_Pointer __prev = __cur;
|
|
++__cur;
|
|
for(; __cur != __last; ++__cur, ++__prev)
|
|
std::_Construct(std::__addressof(*__cur),
|
|
_GLIBCXX_MOVE(*__prev));
|
|
*__seed = _GLIBCXX_MOVE(*__prev);
|
|
}
|
|
__catch(...)
|
|
{
|
|
std::_Destroy(__first, __cur);
|
|
__throw_exception_again;
|
|
}
|
|
}
|
|
};
|
|
|
|
template<>
|
|
struct __uninitialized_construct_buf_dispatch<true>
|
|
{
|
|
template<typename _Pointer, typename _ForwardIterator>
|
|
static void
|
|
__ucr(_Pointer, _Pointer, _ForwardIterator) { }
|
|
};
|
|
|
|
// Constructs objects in the range [first, last).
|
|
// Note that while these new objects will take valid values,
|
|
// their exact value is not defined. In particular they may
|
|
// be 'moved from'.
|
|
//
|
|
// While *__seed may be altered during this algorithm, it will have
|
|
// the same value when the algorithm finishes, unless one of the
|
|
// constructions throws.
|
|
//
|
|
// Requirements: _Pointer::value_type(_Tp&&) is valid.
|
|
template<typename _Pointer, typename _ForwardIterator>
|
|
inline void
|
|
__uninitialized_construct_buf(_Pointer __first, _Pointer __last,
|
|
_ForwardIterator __seed)
|
|
{
|
|
typedef typename std::iterator_traits<_Pointer>::value_type
|
|
_ValueType;
|
|
|
|
std::__uninitialized_construct_buf_dispatch<
|
|
__has_trivial_constructor(_ValueType)>::
|
|
__ucr(__first, __last, __seed);
|
|
}
|
|
|
|
template<typename _ForwardIterator, typename _Tp>
|
|
_Temporary_buffer<_ForwardIterator, _Tp>::
|
|
_Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)
|
|
: _M_original_len(std::distance(__first, __last)),
|
|
_M_len(0), _M_buffer(0)
|
|
{
|
|
__try
|
|
{
|
|
std::pair<pointer, size_type> __p(std::get_temporary_buffer<
|
|
value_type>(_M_original_len));
|
|
_M_buffer = __p.first;
|
|
_M_len = __p.second;
|
|
if (_M_buffer)
|
|
std::__uninitialized_construct_buf(_M_buffer, _M_buffer + _M_len,
|
|
__first);
|
|
}
|
|
__catch(...)
|
|
{
|
|
std::return_temporary_buffer(_M_buffer);
|
|
_M_buffer = 0;
|
|
_M_len = 0;
|
|
__throw_exception_again;
|
|
}
|
|
}
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace
|
|
|
|
#endif /* _STL_TEMPBUF_H */
|
|
|