ClickHouse/src/Storages/MergeTree/MergeTreeDataPartTTLInfo.h
2022-09-02 08:54:48 +00:00

80 lines
2.4 KiB
C++

#pragma once
#include <IO/WriteBufferFromFile.h>
#include <IO/ReadBufferFromFile.h>
#include <Storages/TTLDescription.h>
#include <map>
#include <optional>
namespace DB
{
/// Minimal and maximal ttl for column or table
struct MergeTreeDataPartTTLInfo
{
time_t min = 0;
time_t max = 0;
/// This TTL was computed on completely expired part. It doesn't make sense
/// to select such parts for TTL again. But make sense to recalculate TTL
/// again for merge with multiple parts.
std::optional<bool> ttl_finished;
bool finished() const { return ttl_finished.value_or(false); }
void update(time_t time);
void update(const MergeTreeDataPartTTLInfo & other_info);
};
/// Order is important as it would be serialized and hashed for checksums
using TTLInfoMap = std::map<String, MergeTreeDataPartTTLInfo>;
/// PartTTLInfo for all columns and table with minimal ttl for whole part
struct MergeTreeDataPartTTLInfos
{
TTLInfoMap columns_ttl;
MergeTreeDataPartTTLInfo table_ttl;
/// `part_min_ttl` and `part_max_ttl` are TTLs which are used for selecting parts
/// to merge in order to remove expired rows.
time_t part_min_ttl = 0;
time_t part_max_ttl = 0;
TTLInfoMap rows_where_ttl;
TTLInfoMap moves_ttl;
TTLInfoMap recompression_ttl;
TTLInfoMap group_by_ttl;
/// Return the smallest max recompression TTL value
time_t getMinimalMaxRecompressionTTL() const;
void read(ReadBuffer & in);
void write(WriteBuffer & out) const;
void update(const MergeTreeDataPartTTLInfos & other_infos);
/// Has any TTLs which are not calculated on completely expired parts.
bool hasAnyNonFinishedTTLs() const;
void updatePartMinMaxTTL(time_t time_min, time_t time_max)
{
if (time_min && (!part_min_ttl || time_min < part_min_ttl))
part_min_ttl = time_min;
if (time_max && (!part_max_ttl || time_max > part_max_ttl))
part_max_ttl = time_max;
}
bool empty() const
{
/// part_min_ttl in minimum of rows, rows_where and group_by TTLs
return !part_min_ttl && moves_ttl.empty() && recompression_ttl.empty() && columns_ttl.empty();
}
};
/// Selects the most appropriate TTLDescription using TTL info and current time.
std::optional<TTLDescription> selectTTLDescriptionForTTLInfos(const TTLDescriptions & descriptions, const TTLInfoMap & ttl_info_map, time_t current_time, bool use_max);
}