darling-bmalloc/bmalloc/Range.h
2017-08-12 10:26:17 -07:00

74 lines
2.2 KiB
C++

/*
* Copyright (C) 2014 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef Range_h
#define Range_h
#include <algorithm>
#include <cstddef>
namespace bmalloc {
class Range {
public:
Range()
: m_begin(0)
, m_size(0)
{
}
Range(void* start, size_t size)
: m_begin(static_cast<char*>(start))
, m_size(size)
{
}
char* begin() const { return m_begin; }
char* end() const { return m_begin + m_size; }
size_t size() const { return m_size; }
bool operator!() const { return !m_size; }
explicit operator bool() const { return !!*this; }
bool operator<(const Range& other) const { return m_begin < other.m_begin; }
private:
char* m_begin;
size_t m_size;
};
inline bool canMerge(const Range& a, const Range& b)
{
return a.begin() == b.end() || a.end() == b.begin();
}
inline Range merge(const Range& a, const Range& b)
{
return Range(std::min(a.begin(), b.begin()), a.size() + b.size());
}
} // namespace bmalloc
#endif // Range_h