/* * Copyright (C) 1996-2018 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_FS_ROCK_DB_CELL_H #define SQUID_FS_ROCK_DB_CELL_H #include "typedefs.h" namespace Rock { /** \ingroup Rock * Meta-information at the beginning of every db cell. * Links multiple map slots belonging to the same entry into an entry chain. * Stored on disk and used as sizeof() argument so it must remain POD. */ class DbCellHeader { public: DbCellHeader(); /// true iff no entry occupies this slot bool empty() const { return !firstSlot && !nextSlot && !payloadSize; } /* members below are not meaningful if empty() */ /// whether this slot is not corrupted bool sane(const size_t slotSize, int slotLimit) const { return 0 <= firstSlot && firstSlot < slotLimit && -1 <= nextSlot && nextSlot < slotLimit && version > 0 && 0 < payloadSize && payloadSize <= slotSize - sizeof(DbCellHeader); } uint64_t key[2]; ///< StoreEntry key uint64_t entrySize; ///< total entry content size or zero if still unknown uint32_t payloadSize; ///< slot contents size, always positive uint32_t version; ///< detects conflicts among same-key entries sfileno firstSlot; ///< slot ID of the first slot occupied by the entry sfileno nextSlot; ///< slot ID of the next slot occupied by the entry }; } // namespace Rock #endif /* SQUID_FS_ROCK_DB_CELL_H */