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/*
* include/framework/reconstruction/LevelingPolicy.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 BackgroundTieringPolicy : public ReconstructionPolicy<ShardType, QueryType> {
typedef std::vector<std::shared_ptr<InternalLevel<ShardType, QueryType>>>
LevelVector;
public:
BackgroundTieringPolicy(size_t scale_factor, size_t buffer_size)
: m_scale_factor(scale_factor), m_buffer_size(buffer_size) {}
std::vector<ReconstructionVector> get_reconstruction_tasks(
const Version<ShardType, QueryType> *version, LockManager &lock_mngr) const override {
std::vector<ReconstructionVector> reconstructions;
auto levels = version->get_structure()->get_level_vector();
if (levels[0]->get_shard_count() == 0) {
return {};
}
level_index target_level = find_reconstruction_target(levels);
assert(target_level != -1);
level_index source_level = 0;
if (target_level == invalid_level_idx) {
/* grow */
target_level = levels.size();
}
for (level_index i = target_level; i > source_level; i--) {
if (lock_mngr.take_lock(i-1)) {
fprintf(stderr, "[I] Taking lock on %ld (%ld)\n", i-1, version->get_id());
ReconstructionVector recon;
size_t target_reccnt =
(i < (level_index)levels.size()) ? levels[i]->get_record_count() : 0;
size_t total_reccnt = levels[i - 1]->get_record_count() + target_reccnt;
std::vector<ShardID> shards;
for (ssize_t j=0; j<(ssize_t)levels[i-1]->get_shard_count(); j++) {
shards.push_back({i-1, j});
}
recon.add_reconstruction(shards, i, total_reccnt, ReconstructionType::Compact);
reconstructions.push_back(recon);
} else {
fprintf(stderr, "[I] Failed to get lock on %ld (%ld)\n", i-1, version->get_id());
}
}
return reconstructions;
}
ReconstructionVector
get_flush_tasks(const Version<ShardType, QueryType> *version) const override {
ReconstructionVector reconstructions;
return reconstructions;
}
private:
level_index find_reconstruction_target(LevelVector &levels) const {
level_index target_level = invalid_level_idx;
for (level_index i = 1; i < (level_index)levels.size(); i++) {
if (levels[i]->get_shard_count() + 1 <= capacity()) {
target_level = i;
break;
}
}
return target_level;
}
inline size_t capacity() const { return m_scale_factor; }
size_t m_scale_factor;
size_t m_buffer_size;
};
} // namespace de
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