1/*
2 * Copyright (C) 2014 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef Range_h
27#define Range_h
28
29#include <algorithm>
30#include <cstddef>
31
32namespace bmalloc {
33
34class Range {
35public:
36 Range()
37 : m_begin(0)
38 , m_size(0)
39 {
40 }
41
42 Range(void* start, size_t size)
43 : m_begin(static_cast<char*>(start))
44 , m_size(size)
45 {
46 }
47
48 char* begin() const { return m_begin; }
49 char* end() const { return m_begin + m_size; }
50 size_t size() const { return m_size; }
51
52 bool operator!() const { return !m_size; }
53 explicit operator bool() const { return !!*this; }
54 bool operator<(const Range& other) const { return m_begin < other.m_begin; }
55
56private:
57 char* m_begin;
58 size_t m_size;
59};
60
61inline bool canMerge(const Range& a, const Range& b)
62{
63 return a.begin() == b.end() || a.end() == b.begin();
64}
65
66inline Range merge(const Range& a, const Range& b)
67{
68 return Range(std::min(a.begin(), b.begin()), a.size() + b.size());
69}
70
71} // namespace bmalloc
72
73#endif // Range_h
74