jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2022, Jan de Visser <jan@de-visser.net>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <LibSQL/ResultSet.h>
8
9namespace SQL {
10
11size_t ResultSet::binary_search(Tuple const& sort_key, size_t low, size_t high)
12{
13 if (high <= low) {
14 auto compare = sort_key.compare(at(low).sort_key);
15 return (compare > 0) ? low + 1 : low;
16 }
17
18 auto mid = (low + high) / 2;
19 auto compare = sort_key.compare(at(mid).sort_key);
20 if (compare == 0)
21 return mid + 1;
22
23 if (compare > 0)
24 return binary_search(sort_key, mid + 1, high);
25 return binary_search(sort_key, low, mid);
26}
27
28void ResultSet::insert_row(Tuple const& row, Tuple const& sort_key)
29{
30 if ((sort_key.size() == 0) || is_empty()) {
31 empend(row, sort_key);
32 return;
33 }
34 auto ix = binary_search(sort_key, 0, size() - 1);
35 insert(ix, ResultRow { row, sort_key });
36}
37
38void ResultSet::limit(size_t offset, size_t limit)
39{
40 if (offset > 0) {
41 if (offset > size()) {
42 clear();
43 return;
44 }
45
46 remove(0, offset);
47 }
48
49 if (size() > limit)
50 remove(limit, size() - limit);
51}
52
53}