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/*
* include/framework/reconstruction/FixedShardCountPolicy.h
*
* Copyright (C) 2023-2024 Douglas B. Rumbaugh <drumbaugh@psu.edu>
* Dong Xie <dongx@psu.edu>
*
* Distributed under the Modified BSD License.
*
*/
#pragma once
#include <cmath>
#include "framework/reconstruction/ReconstructionPolicy.h"
#include "framework/scheduling/Version.h"
#include "util/types.h"
namespace de {
template <ShardInterface ShardType, QueryInterface<ShardType> QueryType>
class FixedShardCountPolicy : public ReconstructionPolicy<ShardType, QueryType> {
typedef std::vector<std::shared_ptr<InternalLevel<ShardType, QueryType>>>
LevelVector;
public:
FixedShardCountPolicy(size_t buffer_size, size_t shard_count, size_t max_record_count)
: m_buffer_size(buffer_size), m_shard_count(shard_count), m_max_reccnt(max_record_count) {}
std::vector<ReconstructionVector>
get_reconstruction_tasks(const Version<ShardType, QueryType> *version, LockManager &lock_mngr) const override {
return {};
}
ReconstructionVector
get_flush_tasks(const Version<ShardType, QueryType> *version) const override {
auto levels = version->get_structure()->get_level_vector();
ReconstructionVector v;
/* if this is the very first flush, there won't be an L1 yet */
if (levels.size() > 1 && levels[1]->get_shard_count() > 0) {
ShardID last_shid = {1, (shard_index) (levels[1]->get_shard_count() - 1)};
if (levels[1]->get_shard(last_shid.shard_idx)->get_record_count() + m_buffer_size <= capacity()) {
auto task = ReconstructionTask {
{{0, 0}, last_shid}, 1, m_buffer_size,ReconstructionType::Merge
};
v.add_reconstruction(task);
return v;
}
}
auto task = ReconstructionTask {
{{0, 0}}, 1, m_buffer_size, ReconstructionType::Append
};
v.add_reconstruction(task);
return v;
}
private:
inline size_t capacity() const {
double bps = (double) m_max_reccnt / (double) m_buffer_size / m_shard_count;
return ceil(bps) * m_buffer_size;
}
size_t m_buffer_size;
size_t m_shard_count;
size_t m_max_reccnt;
};
} // namespace de
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