1//========================================================================
2//
3// PopplerCache.h
4//
5// This file is licensed under the GPLv2 or later
6//
7// Copyright (C) 2009 Koji Otani <sho@bbr.jp>
8// Copyright (C) 2009, 2010, 2017, 2018, 2021 Albert Astals Cid <aacid@kde.org>
9// Copyright (C) 2010 Carlos Garcia Campos <carlosgc@gnome.org>
10// Copyright (C) 2018 Adam Reichold <adam.reichold@t-online.de>
11//
12//========================================================================
13
14#ifndef POPPLER_CACHE_H
15#define POPPLER_CACHE_H
16
17#include <algorithm>
18#include <memory>
19#include <utility>
20#include <vector>
21
22template<typename Key, typename Item>
23class PopplerCache
24{
25public:
26 PopplerCache(const PopplerCache &) = delete;
27 PopplerCache &operator=(const PopplerCache &other) = delete;
28
29 explicit PopplerCache(std::size_t cacheSizeA) { entries.reserve(cacheSizeA); }
30
31 /* The item returned is owned by the cache */
32 Item *lookup(const Key &key)
33 {
34 if (!entries.empty() && entries.front().first == key) {
35 return entries.front().second.get();
36 }
37
38 for (auto it = entries.begin(); it != entries.end(); ++it) {
39 if (it->first == key) {
40 auto *item = it->second.get();
41
42 std::rotate(entries.begin(), it, std::next(it));
43
44 return item;
45 }
46 }
47
48 return nullptr;
49 }
50
51 /* The key and item pointers ownership is taken by the cache */
52 void put(const Key &key, Item *item)
53 {
54 if (entries.size() == entries.capacity()) {
55 entries.pop_back();
56 }
57
58 entries.emplace(entries.begin(), key, std::unique_ptr<Item> { item });
59 }
60
61private:
62 std::vector<std::pair<Key, std::unique_ptr<Item>>> entries;
63};
64
65#endif
66

source code of poppler/poppler/PopplerCache.h