chore: initial commit

rediska/cache/lru/LRU.hpp

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <list>
+#include <shared_mutex>
+#include <unordered_map>
+#include "rediska/cache/lru/LRUConfig.hpp"
+#include "rediska/cache/lru/LRUItemMetadata.hpp"
+#include "rediska/cache/types.hpp"
+#include "rediska/common/MessageArguments.hpp"
+#include "rediska/common/types.hpp"
+#include "rediska/cache/CachePolicy.hpp"
+
+namespace cache {
+    class LRU : public CachePolicy {
+    public:
+        using ItemMetadata = LRUItemMetadata;
+        using ItemHandle = struct {
+            CacheValue value;
+            ItemMetadata metadata;
+        };
+        using CacheNode = struct {
+            CacheKey key;
+            ItemHandle location;
+        };
+
+        LRU(LRUConfig config, CacheOpCallback callback);
+        ~LRU() = default;
+
+        void get(CacheKey&& key) override;
+
+        void set(CacheKey&& key, CacheValue&& value, TTL ttl) override;
+
+        void applyTo(CacheKey&& key, OperationId op, MessageArguments&& args) override;
+
+    private:
+        std::list<CacheNode> lru_list_;
+        std::unordered_map<CacheKey, std::list<CacheNode>::iterator> keyToItem_;
+
+        std::shared_mutex mutex_;
+
+        LRUConfig config_;
+        CacheOpCallback callback_;
+
+        void evict() override;
+
+        void evict(const std::unordered_map<CacheKey, std::list<CacheNode>::iterator>::iterator node);
+
+        inline bool isFull() const override;
+
+        void resetTTLIfEnabled(CacheNode& key);
+    };
+}