mirror of https://gitee.com/bigwinds/arangodb
148 lines
6.1 KiB
C++
148 lines
6.1 KiB
C++
////////////////////////////////////////////////////////////////////////////////
|
|
/// DISCLAIMER
|
|
///
|
|
/// Copyright 2014-2017 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 Daniel H. Larkin
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#ifndef ARANGODB_CACHE_METADATA_H
|
|
#define ARANGODB_CACHE_METADATA_H
|
|
|
|
#include "Basics/Common.h"
|
|
#include "Cache/State.h"
|
|
|
|
#include <atomic>
|
|
#include <cstdint>
|
|
|
|
namespace arangodb {
|
|
namespace cache {
|
|
|
|
class Cache; // forward declaration
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Metadata object to facilitate information sharing between individual
|
|
/// Cache instances and Manager.
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
struct Metadata {
|
|
// info about allocated memory
|
|
uint64_t fixedSize;
|
|
uint64_t tableSize;
|
|
uint64_t maxSize;
|
|
uint64_t allocatedSize;
|
|
uint64_t deservedSize;
|
|
|
|
// vital information about memory usage
|
|
uint64_t usage;
|
|
uint64_t softUsageLimit;
|
|
uint64_t hardUsageLimit;
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Default constructor for placeholder objects.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
Metadata();
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Initializes record with given information.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
Metadata(uint64_t usage, uint64_t fixed, uint64_t table, uint64_t max);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Initializes record from an existing record.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
Metadata(Metadata const& other);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Initializes record from an existing record.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
Metadata& operator=(Metadata const& other);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Locks the record.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
void lock();
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Unlocks the record. Requires record to be locked.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
void unlock();
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Returns true if the record is locked, false otherwise.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
bool isLocked() const;
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Adjusts usage by the specified amount if it will not violate
|
|
/// limits. Requires record to be locked.
|
|
///
|
|
/// Returns true if adjusted, false otherwise. Used by caches to check-and-set
|
|
/// in a single operation to determine whether they can afford to store a new
|
|
/// value.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
bool adjustUsageIfAllowed(int64_t usageChange);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Sets the soft and hard usage limits. Requires record to be locked.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
bool adjustLimits(uint64_t softLimit, uint64_t hardLimit);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Sets the deserved size. Requires record to be locked.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
uint64_t adjustDeserved(uint64_t deserved);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Calculates the new usage limit based on deserved size and other
|
|
/// values. Requires record to be locked.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
uint64_t newLimit();
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Checks feasibility of new table size prior to migration. Requires
|
|
/// record to be locked.
|
|
///
|
|
/// If migrating to table of new size would exceed either deserved or maximum
|
|
/// size, then returns false.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
bool migrationAllowed(uint64_t newTableSize);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Sets the table size after migration. Requires record to be locked.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
void changeTable(uint64_t newTableSize);
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Checks if flag is set in state. Requires record to be locked.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
bool isSet(State::Flag flag) const;
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
/// @brief Toggles flag in state. Requires record to be locked.
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
void toggleFlag(State::Flag flag);
|
|
|
|
private:
|
|
State _state;
|
|
};
|
|
|
|
}; // end namespace cache
|
|
}; // end namespace arangodb
|
|
|
|
#endif
|