/* * Copyright (C) 1996-2023 The Squid Software Foundation and contributors * * Squid software is distributed under GPLv2+ license and includes * contributions from numerous individuals and organizations. * Please see the COPYING and CONTRIBUTORS files for details. */ #ifndef SQUID_SRC_STORE_STORAGE_H #define SQUID_SRC_STORE_STORAGE_H #include "base/RefCount.h" #include "http/RequestMethod.h" #include "store/forward.h" #include "store_key_md5.h" class StoreInfoStats; namespace Store { /// A "response storage" abstraction. /// This API is shared among Controller and Controlled classes. class Storage: public RefCountable { public: ~Storage() override {} /// create system resources needed for this store to operate in the future virtual void create() = 0; /// Start preparing the store for use. To check readiness, callers should /// use readable() and writable() methods. virtual void init() = 0; /** * The maximum size the store will support in normal use. Inaccuracy is * permitted, but may throw estimates for memory etc out of whack. */ virtual uint64_t maxSize() const = 0; /// the minimum size the store will shrink to via normal housekeeping virtual uint64_t minSize() const = 0; /// current size virtual uint64_t currentSize() const = 0; /// the total number of objects stored right now virtual uint64_t currentCount() const = 0; /// the maximum size of a storable object; -1 if unlimited virtual int64_t maxObjectSize() const = 0; /// collect statistics virtual void getStats(StoreInfoStats &stats) const = 0; /** * Output stats to the provided store entry. * TODO: make these calls asynchronous */ virtual void stat(StoreEntry &e) const = 0; /// Prevent new get() calls from returning the matching entry. /// If the matching entry is unused, it may be removed from the store now. /// The store entry is matched using either `e` attachment info or `e.key`. virtual void evictCached(StoreEntry &e) = 0; /// An evictCached() equivalent for callers that did not get() a StoreEntry. /// Callers with StoreEntry objects must use evictCached() instead. virtual void evictIfFound(const cache_key *) = 0; /// called once every main loop iteration; TODO: Move to UFS code. virtual int callback() { return 0; } /// perform regular periodic maintenance; TODO: move to UFSSwapDir::Maintain virtual void maintain() = 0; /// prepare for shutdown virtual void sync() {} }; } // namespace Store #endif /* SQUID_SRC_STORE_STORAGE_H */