Files
scylladb/encoding_stats.hh
Ernest Zaslavsky 5ba5aec1f8 treewide: Move mutation related files to a mutation directory
As requested in #22104, moved the files and fixed other includes and build system.

Moved files:
 - combine.hh
 - collection_mutation.hh
 - collection_mutation.cc
 - converting_mutation_partition_applier.hh
 - converting_mutation_partition_applier.cc
 - counters.hh
 - counters.cc
 - timestamp.hh

Fixes: #22104

This is a cleanup, no need to backport

Closes scylladb/scylladb#25085
2025-09-24 13:23:38 +03:00

78 lines
2.8 KiB
C++

/*
* Copyright (C) 2018-present ScyllaDB
*/
/*
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
*/
#pragma once
#include "gc_clock.hh"
#include "mutation/timestamp.hh"
#include "utils/extremum_tracking.hh"
// Stores statistics on all the updates done to a memtable
// The collected statistics are used for flushing memtable to the disk
struct encoding_stats {
// The fixed epoch corresponds to the one used by Origin - 22/09/2015, 00:00:00, GMT-0:
// Calendar c = Calendar.getInstance(TimeZone.getTimeZone("GMT-0"), Locale.US);
// c.set(Calendar.YEAR, 2015);
// c.set(Calendar.MONTH, Calendar.SEPTEMBER);
// c.set(Calendar.DAY_OF_MONTH, 22);
// c.set(Calendar.HOUR_OF_DAY, 0);
// c.set(Calendar.MINUTE, 0);
// c.set(Calendar.SECOND, 0);
// c.set(Calendar.MILLISECOND, 0);
//
// long TIMESTAMP_EPOCH = c.getTimeInMillis() * 1000; // timestamps should be in microseconds by convention
// int DELETION_TIME_EPOCH = (int)(c.getTimeInMillis() / 1000); // local deletion times are in seconds
// Encoding stats are used for delta-encoding, so we want some default values
// that are just good enough so we take some recent date in the past
static constexpr int32_t deletion_time_epoch = 1442880000;
static constexpr api::timestamp_type timestamp_epoch = api::timestamp_type(deletion_time_epoch) * 1000 * 1000;
static constexpr int32_t ttl_epoch = 0;
api::timestamp_type min_timestamp = timestamp_epoch;
gc_clock::time_point min_local_deletion_time = gc_clock::time_point(gc_clock::duration(deletion_time_epoch));
gc_clock::duration min_ttl = gc_clock::duration(ttl_epoch);
};
class encoding_stats_collector {
private:
min_tracker<api::timestamp_type> min_timestamp;
min_tracker<gc_clock::time_point> min_local_deletion_time;
min_tracker<gc_clock::duration> min_ttl;
protected:
void update_timestamp(api::timestamp_type ts) noexcept {
min_timestamp.update(ts);
}
void update_local_deletion_time(gc_clock::time_point local_deletion_time) noexcept {
min_local_deletion_time.update(local_deletion_time);
}
void update_ttl(gc_clock::duration ttl) noexcept {
min_ttl.update(ttl);
}
public:
encoding_stats_collector() noexcept
: min_timestamp(api::max_timestamp)
, min_local_deletion_time(gc_clock::time_point::max())
, min_ttl(gc_clock::duration::max())
{}
void update(const encoding_stats& other) noexcept {
update_timestamp(other.min_timestamp);
update_local_deletion_time(other.min_local_deletion_time);
update_ttl(other.min_ttl);
}
encoding_stats get() const noexcept {
return { min_timestamp.get(), min_local_deletion_time.get(), min_ttl.get() };
}
};