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//========================================================================
//
// PopplerCache.h
//
// This file is licensed under the GPLv2 or later
//
// Copyright (C) 2009 Koji Otani <sho@bbr.jp>
// Copyright (C) 2009, 2010, 2017, 2018 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2010 Carlos Garcia Campos <carlosgc@gnome.org>
// Copyright (C) 2018 Adam Reichold <adam.reichold@t-online.de>
//
//========================================================================
#ifndef POPPLER_CACHE_H
#define POPPLER_CACHE_H
#include <algorithm>
#include <memory>
#include <utility>
#include <vector>
template<typename Key, typename Item>
class PopplerCache
{
public:
PopplerCache(const PopplerCache &) = delete;
PopplerCache& operator=(const PopplerCache &other) = delete;
PopplerCache(std::size_t cacheSizeA) { entries.reserve(cacheSizeA); }
/* The item returned is owned by the cache */
Item *lookup(const Key &key) {
if (!entries.empty() && entries.front().first == key) {
return entries.front().second.get();
}
for (auto it = entries.begin(); it != entries.end(); ++it) {
if (it->first == key) {
auto *item = it->second.get();
std::rotate(entries.begin(), it, std::next(it));
return item;
}
}
return nullptr;
}
/* The key and item pointers ownership is taken by the cache */
void put(const Key &key, Item *item) {
if (entries.size() == entries.capacity()) {
entries.pop_back();
}
entries.emplace(entries.begin(), key, std::unique_ptr<Item>{item});
}
private:
std::vector<std::pair<Key, std::unique_ptr<Item>>> entries;
};
#endif