milvus/cpp/src/cache/Cache.h

////////////////////////////////////////////////////////////////////////////////
// Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
// Unauthorized copying of this file, via any medium is strictly prohibited.
// Proprietary and confidential.
////////////////////////////////////////////////////////////////////////////////

#pragma once

#include <string>
#include <mutex>
#include <atomic>

#include "LRU.h"
#include "DataObj.h"

namespace zilliz {
namespace milvus {
namespace cache {

const std::string SWAP_DIR = ".CACHE";

class Cache {
private:
    class CacheObj {
    public:
        CacheObj() = delete;

        CacheObj(const DataObjPtr& data)
        : data_(data) {
        }

    public:
        DataObjPtr data_ = nullptr;
    };

    using CacheObjPtr = std::shared_ptr<CacheObj>;

public:
    //mem_capacity, units:GB
    Cache(int64_t capacity_gb, uint64_t cache_max_count);
    ~Cache() = default;

    int64_t usage() const { return usage_; }
    int64_t capacity() const { return capacity_; } //unit: BYTE
    void set_capacity(int64_t capacity); //unit: BYTE

    double freemem_percent() const { return freemem_percent_; };
    void set_freemem_percent(double percent) { freemem_percent_ = percent; }
    void set_gpu_ids(std::vector<uint64_t> gpu_ids) { gpu_ids_.assign(gpu_ids.begin(), gpu_ids.end()); }
    std::vector<uint64_t> gpu_ids() const { return gpu_ids_; }

    size_t size() const;
    bool exists(const std::string& key);
    DataObjPtr get(const std::string& key);
    void insert(const std::string& key, const DataObjPtr& data);
    void erase(const std::string& key);
    void print();
    void clear();
    void free_memory();

private:
    int64_t usage_;
    int64_t capacity_;
    double freemem_percent_;
    std::vector<uint64_t> gpu_ids_;

    LRU<std::string, CacheObjPtr> lru_;
    mutable std::mutex mutex_;
};

using CachePtr = std::shared_ptr<Cache>;

}   // cache
}   // milvus
}   // zilliz