ClickHouse/dbms/Storages/MergeTree/TTLMergeSelector.cpp
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

75 lines
1.9 KiB
C++

#include <Storages/MergeTree/TTLMergeSelector.h>
#include <cmath>
#include <algorithm>
namespace DB
{
IMergeSelector::PartsInPartition TTLMergeSelector::select(
const Partitions & partitions,
const size_t max_total_size_to_merge)
{
using Iterator = IMergeSelector::PartsInPartition::const_iterator;
Iterator best_begin;
ssize_t partition_to_merge_index = -1;
time_t partition_to_merge_min_ttl = 0;
for (size_t i = 0; i < partitions.size(); ++i)
{
for (auto it = partitions[i].begin(); it != partitions[i].end(); ++it)
{
time_t ttl = only_drop_parts ? it->max_ttl : it->min_ttl;
if (ttl && (partition_to_merge_index == -1 || ttl < partition_to_merge_min_ttl))
{
partition_to_merge_min_ttl = ttl;
partition_to_merge_index = i;
best_begin = it;
}
}
}
if (partition_to_merge_index == -1 || partition_to_merge_min_ttl > current_time)
return {};
const auto & best_partition = partitions[partition_to_merge_index];
Iterator best_end = best_begin + 1;
size_t total_size = 0;
while (true)
{
time_t ttl = only_drop_parts ? best_begin->max_ttl : best_begin->min_ttl;
if (!ttl || ttl > current_time
|| (max_total_size_to_merge && total_size > max_total_size_to_merge))
{
++best_begin;
break;
}
total_size += best_begin->size;
if (best_begin == best_partition.begin())
break;
--best_begin;
}
while (best_end != best_partition.end())
{
time_t ttl = only_drop_parts ? best_end->max_ttl : best_end->min_ttl;
if (!ttl || ttl > current_time
|| (max_total_size_to_merge && total_size > max_total_size_to_merge))
break;
total_size += best_end->size;
++best_end;
}
return PartsInPartition(best_begin, best_end);
}
}