// Temporary buffer implementation -*- C++ -*-
-// Copyright (C) 2001, 2002 Free Software Foundation, Inc.
+// Copyright (C) 2001-2017 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 2, or (at your option)
+// 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,
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING. If not, write to the Free
-// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
-// USA.
+// 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.
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
+// 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/>.
/*
*
* purpose. It is provided "as is" without express or implied warranty.
*/
-/** @file stl_tempbuf.h
+/** @file bits/stl_tempbuf.h
* This is an internal header file, included by other library headers.
- * You should not attempt to use it directly.
+ * Do not attempt to use it directly. @headername{memory}
*/
-#ifndef __GLIBCPP_INTERNAL_TEMPBUF_H
-#define __GLIBCPP_INTERNAL_TEMPBUF_H
+#ifndef _STL_TEMPBUF_H
+#define _STL_TEMPBUF_H 1
-namespace std
-{
+#include <bits/stl_algobase.h>
+#include <bits/stl_construct.h>
-/**
- * @maint
- * 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.
- * @endmaint
-*/
-template <class _ForwardIterator, class _Tp>
- class _Temporary_buffer
+namespace std _GLIBCXX_VISIBILITY(default)
{
- // concept requirements
- __glibcpp_class_requires(_ForwardIterator, _ForwardIteratorConcept)
-
- ptrdiff_t _M_original_len;
- ptrdiff_t _M_len;
- _Tp* _M_buffer;
-
- // this is basically get_temporary_buffer() all over again
- void _M_allocate_buffer() {
- _M_original_len = _M_len;
- _M_buffer = 0;
-
- if (_M_len > (ptrdiff_t)(INT_MAX / sizeof(_Tp)))
- _M_len = INT_MAX / sizeof(_Tp);
-
- while (_M_len > 0) {
- _M_buffer = (_Tp*) malloc(_M_len * sizeof(_Tp));
- if (_M_buffer)
- break;
- _M_len /= 2;
- }
- }
-
- void _M_initialize_buffer(const _Tp&, __true_type) {}
- void _M_initialize_buffer(const _Tp& val, __false_type) {
- uninitialized_fill_n(_M_buffer, _M_len, val);
- }
-
-public:
- /// As per Table mumble.
- ptrdiff_t size() const { return _M_len; }
- /// Returns the size requested by the constructor; may be >size().
- ptrdiff_t requested_size() const { return _M_original_len; }
- /// As per Table mumble.
- _Tp* begin() { return _M_buffer; }
- /// As per Table mumble.
- _Tp* end() { return _M_buffer + _M_len; }
-
- _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last) {
- // Workaround for a __type_traits bug in the pre-7.3 compiler.
- typedef typename __type_traits<_Tp>::has_trivial_default_constructor
- _Trivial;
-
- try {
- _M_len = distance(__first, __last);
- _M_allocate_buffer();
- if (_M_len > 0)
- _M_initialize_buffer(*__first, _Trivial());
+_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);
}
- catch(...)
- {
- free(_M_buffer);
- _M_buffer = 0;
- _M_len = 0;
- __throw_exception_again;
+
+ /**
+ * @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);
}
- }
-
- ~_Temporary_buffer() {
- _Destroy(_M_buffer, _M_buffer + _M_len);
- free(_M_buffer);
- }
-
-private:
- // Disable copy constructor and assignment operator.
- _Temporary_buffer(const _Temporary_buffer&) {}
- void operator=(const _Temporary_buffer&) {}
-};
-
-} // namespace std
-
-#endif /* __GLIBCPP_INTERNAL_TEMPBUF_H */
+
+ 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 */