rocksdb/cache/charged_cache.h

58 lines
1.9 KiB
C++

// Copyright (c) Meta Platforms, Inc. and affiliates.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#include <string>
#include "port/port.h"
#include "rocksdb/advanced_cache.h"
namespace ROCKSDB_NAMESPACE {
class ConcurrentCacheReservationManager;
// A cache interface which wraps around another cache and takes care of
// reserving space in block cache towards a single global memory limit, and
// forwards all the calls to the underlying cache.
class ChargedCache : public CacheWrapper {
public:
ChargedCache(std::shared_ptr<Cache> cache,
std::shared_ptr<Cache> block_cache);
Status Insert(const Slice& key, ObjectPtr obj, const CacheItemHelper* helper,
size_t charge, Handle** handle = nullptr,
Priority priority = Priority::LOW) override;
Cache::Handle* Lookup(const Slice& key, const CacheItemHelper* helper,
CreateContext* create_context,
Priority priority = Priority::LOW, bool wait = true,
Statistics* stats = nullptr) override;
bool Release(Cache::Handle* handle, bool useful,
bool erase_if_last_ref = false) override;
bool Release(Cache::Handle* handle, bool erase_if_last_ref = false) override;
void Erase(const Slice& key) override;
void EraseUnRefEntries() override;
static const char* kClassName() { return "ChargedCache"; }
const char* Name() const override { return kClassName(); }
void SetCapacity(size_t capacity) override;
inline Cache* GetCache() const { return target_.get(); }
inline ConcurrentCacheReservationManager* TEST_GetCacheReservationManager()
const {
return cache_res_mgr_.get();
}
private:
std::shared_ptr<ConcurrentCacheReservationManager> cache_res_mgr_;
};
} // namespace ROCKSDB_NAMESPACE