mirror of https://gitee.com/bigwinds/arangodb
102 lines
3.4 KiB
C++
102 lines
3.4 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_SHARDING_SHARDING_STRATEGY_DEFAULT_H
|
|
#define ARANGOD_SHARDING_SHARDING_STRATEGY_DEFAULT_H 1
|
|
|
|
#include "Basics/Common.h"
|
|
#include "Basics/Mutex.h"
|
|
#include "Sharding/ShardingStrategy.h"
|
|
|
|
#include <velocypack/Slice.h>
|
|
|
|
namespace arangodb {
|
|
class ShardingInfo;
|
|
|
|
/// @brief a sharding implementation that will always fail when asking
|
|
/// for a shard. this can be used on the DB server or on the single server
|
|
class ShardingStrategyNone final : public ShardingStrategy {
|
|
public:
|
|
ShardingStrategyNone();
|
|
|
|
std::string const& name() const override { return NAME; }
|
|
|
|
static std::string const NAME;
|
|
|
|
/// @brief does not really matter here
|
|
bool usesDefaultShardKeys() override { return true; }
|
|
|
|
int getResponsibleShard(arangodb::velocypack::Slice,
|
|
bool docComplete, ShardID& shardID,
|
|
bool& usesDefaultShardKeys,
|
|
std::string const& key = "") override;
|
|
};
|
|
|
|
/// @brief base class for hash-based sharding
|
|
class ShardingStrategyHashBase : public ShardingStrategy {
|
|
public:
|
|
explicit ShardingStrategyHashBase(ShardingInfo* sharding);
|
|
|
|
virtual int getResponsibleShard(arangodb::velocypack::Slice,
|
|
bool docComplete, ShardID& shardID,
|
|
bool& usesDefaultShardKeys,
|
|
std::string const& key = "") override;
|
|
|
|
/// @brief does not really matter here
|
|
bool usesDefaultShardKeys() override { return _usesDefaultShardKeys; }
|
|
|
|
virtual uint64_t hashByAttributes(
|
|
arangodb::velocypack::Slice slice, std::vector<std::string> const& attributes,
|
|
bool docComplete, int& error, std::string const& key) = 0;
|
|
|
|
private:
|
|
void determineShards();
|
|
|
|
protected:
|
|
ShardingInfo* _sharding;
|
|
std::vector<ShardID> _shards;
|
|
bool _usesDefaultShardKeys;
|
|
std::atomic<bool> _shardsSet;
|
|
Mutex _shardsSetMutex;
|
|
};
|
|
|
|
/// @brief old version of the sharding used in the community edition
|
|
/// this is DEPRECATED and should not be used for new collections
|
|
class ShardingStrategyCommunityCompat final : public ShardingStrategyHashBase {
|
|
public:
|
|
explicit ShardingStrategyCommunityCompat(ShardingInfo* sharding);
|
|
|
|
std::string const& name() const override { return NAME; }
|
|
|
|
static std::string const NAME;
|
|
|
|
protected:
|
|
uint64_t hashByAttributes(
|
|
arangodb::velocypack::Slice slice, std::vector<std::string> const& attributes,
|
|
bool docComplete, int& error, std::string const& key) override;
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|