diff --git a/common/CMakeLists.txt b/common/CMakeLists.txt index 2295beeca5..1b97440126 100644 --- a/common/CMakeLists.txt +++ b/common/CMakeLists.txt @@ -67,6 +67,7 @@ target_sources(common PRIVATE FileSystem.h General.h HashCombine.h + LRUCache.h MemcpyFast.h MemsetFast.inl MD5Digest.h diff --git a/common/LRUCache.h b/common/LRUCache.h new file mode 100644 index 0000000000..96663d118b --- /dev/null +++ b/common/LRUCache.h @@ -0,0 +1,137 @@ +/* PCSX2 - PS2 Emulator for PCs + * Copyright (C) 2002-2022 PCSX2 Dev Team + * + * PCSX2 is free software: you can redistribute it and/or modify it under the terms + * of the GNU Lesser General Public License as published by the Free Software Found- + * ation, either version 3 of the License, or (at your option) any later version. + * + * PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; + * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR + * PURPOSE. See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along with PCSX2. + * If not, see . + */ + +#pragma once +#include +#include + +template +class LRUCache +{ + using CounterType = std::uint64_t; + + struct Item + { + V value; + CounterType last_access; + }; + + using MapType = std::map; + +public: + LRUCache(std::size_t max_capacity = 16, bool manual_evict = false) + : m_max_capacity(max_capacity) + , m_manual_evict(manual_evict) + { + } + ~LRUCache() = default; + + std::size_t GetSize() const { return m_items.size(); } + std::size_t GetMaxCapacity() const { return m_max_capacity; } + + void Clear() { m_items.clear(); } + + void SetMaxCapacity(std::size_t capacity) + { + m_max_capacity = capacity; + if (m_items.size() > m_max_capacity) + Evict(m_items.size() - m_max_capacity); + } + + template + V* Lookup(const KeyT& key) + { + auto iter = m_items.find(key); + if (iter == m_items.end()) + return nullptr; + + iter->second.last_access = ++m_last_counter; + return &iter->second.value; + } + + V* Insert(K key, V value) + { + ShrinkForNewItem(); + + auto iter = m_items.find(key); + if (iter != m_items.end()) + { + iter->second.value = std::move(value); + iter->second.last_access = ++m_last_counter; + return &iter->second.value; + } + else + { + Item it; + it.last_access = ++m_last_counter; + it.value = std::move(value); + auto ip = m_items.emplace(std::move(key), std::move(it)); + return &ip.first->second.value; + } + } + + void Evict(std::size_t count = 1) + { + while (m_items.size() >= count) + { + typename MapType::iterator lowest = m_items.end(); + for (auto iter = m_items.begin(); iter != m_items.end(); ++iter) + { + if (lowest == m_items.end() || iter->second.last_access < lowest->second.last_access) + lowest = iter; + } + m_items.erase(lowest); + } + } + + template + bool Remove(const KeyT& key) + { + auto iter = m_items.find(key); + if (iter == m_items.end()) + return false; + + m_items.erase(iter); + return true; + } + + void SetManualEvict(bool block) + { + m_manual_evict = block; + if (!m_manual_evict) + ManualEvict(); + } + + void ManualEvict() + { + // evict if we went over + while (m_items.size() > m_max_capacity) + Evict(m_items.size() - (m_max_capacity - 1)); + } + +private: + void ShrinkForNewItem() + { + if (m_items.size() < m_max_capacity) + return; + + Evict(m_items.size() - (m_max_capacity - 1)); + } + + MapType m_items; + CounterType m_last_counter = 0; + std::size_t m_max_capacity = 0; + bool m_manual_evict = false; +}; \ No newline at end of file diff --git a/common/common.vcxproj b/common/common.vcxproj index 861365fa69..6e64ed511c 100644 --- a/common/common.vcxproj +++ b/common/common.vcxproj @@ -135,6 +135,7 @@ + @@ -208,4 +209,4 @@ - + \ No newline at end of file diff --git a/common/common.vcxproj.filters b/common/common.vcxproj.filters index 55cf5d1c09..0a240cf46c 100644 --- a/common/common.vcxproj.filters +++ b/common/common.vcxproj.filters @@ -429,6 +429,9 @@ Header Files + + Header Files +