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arangodb/arangod/MMFiles/MMFilesWalSlot.h

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3.7 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_MMFILES_WAL_SLOT_H
#define ARANGOD_MMFILES_WAL_SLOT_H 1
#include "Basics/Common.h"
#include "MMFiles/MMFilesWalLogfile.h"
namespace arangodb {
class MMFilesWalSlots;
class MMFilesWalMarker;
class MMFilesWalSlot {
friend class MMFilesWalSlots;
public:
/// @brief tick typedef
typedef TRI_voc_tick_t TickType;
/// @brief slot status typedef
enum class StatusType : uint32_t {
UNUSED = 0,
USED = 1,
RETURNED = 2,
RETURNED_WFS = 3
};
/// @brief create a slot
private:
MMFilesWalSlot();
public:
/// @brief return the tick assigned to the slot
inline MMFilesWalSlot::TickType tick() const { return _tick; }
/// @brief return the logfile id assigned to the slot
inline MMFilesWalLogfile::IdType logfileId() const {
if (_logfile != nullptr) {
return _logfile->id();
}
return 0;
}
/// @brief return the logfile assigned to the slot
inline MMFilesWalLogfile* logfile() const { return _logfile; }
/// @brief return the raw memory pointer assigned to the slot
inline void* mem() const { return _mem; }
/// @brief return the memory size assigned to the slot
inline uint32_t size() const { return _size; }
/// @brief return the slot status as a string
std::string statusText() const;
/// @brief calculate the CRC and length values for the slot and
/// store them in the marker
void finalize(MMFilesWalMarker const*);
/// @brief calculate the CRC value for the source region (this will modify
/// the source region) and copy the calculated marker data into the slot
void fill(void*, size_t);
private:
/// @brief whether or not the slot is unused
inline bool isUnused() const { return _status == StatusType::UNUSED; }
/// @brief whether or not the slot is used
inline bool isUsed() const { return _status == StatusType::USED; }
/// @brief whether or not the slot is returned
inline bool isReturned() const {
return (_status == StatusType::RETURNED || _status == StatusType::RETURNED_WFS);
}
/// @brief whether or not a sync was requested for the slot
inline bool waitForSync() const {
return (_status == StatusType::RETURNED_WFS);
}
/// @brief mark as slot as unused
void setUnused();
/// @brief mark as slot as used
void setUsed(void*, uint32_t, MMFilesWalLogfile*, MMFilesWalSlot::TickType);
/// @brief mark as slot as returned
void setReturned(bool waitForSync);
private:
/// @brief slot tick
MMFilesWalSlot::TickType _tick;
/// @brief slot logfile
MMFilesWalLogfile* _logfile;
/// @brief slot raw memory pointer
void* _mem;
#ifdef TRI_PADDING_32
char _padding[4];
#endif
/// @brief slot raw memory size
uint32_t _size;
/// @brief slot status
StatusType _status;
};
static_assert(sizeof(MMFilesWalSlot) == 32, "invalid slot size");
} // namespace arangodb
#endif