1/*
2 * Copyright (C) 2013, 2015-2016 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#pragma once
27
28namespace WTF {
29
30template<typename T>
31class Insertion {
32public:
33 Insertion() { }
34
35 template<typename U>
36 Insertion(size_t index, U&& element)
37 : m_index(index)
38 , m_element(std::forward<U>(element))
39 {
40 }
41
42 size_t index() const { return m_index; }
43 const T& element() const { return m_element; }
44 T& element() { return m_element; }
45
46 bool operator<(const Insertion& other) const
47 {
48 return m_index < other.m_index;
49 }
50
51private:
52 size_t m_index { 0 };
53 T m_element { };
54};
55
56template<typename TargetVectorType, typename InsertionVectorType>
57size_t executeInsertions(TargetVectorType& target, InsertionVectorType& insertions)
58{
59 size_t numInsertions = insertions.size();
60 if (!numInsertions)
61 return 0;
62 size_t originalTargetSize = target.size();
63 target.grow(target.size() + numInsertions);
64 size_t lastIndex = target.size();
65 for (size_t indexInInsertions = numInsertions; indexInInsertions--;) {
66 ASSERT(!indexInInsertions || insertions[indexInInsertions].index() >= insertions[indexInInsertions - 1].index());
67 ASSERT_UNUSED(originalTargetSize, insertions[indexInInsertions].index() <= originalTargetSize);
68 size_t firstIndex = insertions[indexInInsertions].index() + indexInInsertions;
69 size_t indexOffset = indexInInsertions + 1;
70 for (size_t i = lastIndex; --i > firstIndex;)
71 target[i] = WTFMove(target[i - indexOffset]);
72 target[firstIndex] = WTFMove(insertions[indexInInsertions].element());
73 lastIndex = firstIndex;
74 }
75 insertions.shrink(0);
76 return numInsertions;
77}
78
79} // namespace WTF
80
81using WTF::Insertion;
82using WTF::executeInsertions;
83