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