mirror of
https://github.com/scylladb/scylladb.git
synced 2026-05-22 15:52:13 +00:00
67 lines
2.2 KiB
C++
67 lines
2.2 KiB
C++
/*
|
|
* Copyright 2024-present ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.1
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "utils/rjson.hh"
|
|
|
|
namespace alternator {
|
|
|
|
/**
|
|
* \brief consumed_capacity_counter is a base class that holds the bookkeeping
|
|
* to calculate RCU and WCU
|
|
*
|
|
* DynamoDB counts read capacity in half-integers - a short
|
|
* eventually-consistent read is counted as 0.5 unit.
|
|
* Because we want our counter to be an integer, we counts half units in
|
|
* our internal calculations.
|
|
*
|
|
* We use consumed_capacity_counter for calculation of a specific action
|
|
*
|
|
* It is also used to update the response if needed.
|
|
*/
|
|
class consumed_capacity_counter {
|
|
public:
|
|
consumed_capacity_counter() = default;
|
|
consumed_capacity_counter(bool should_add_to_response) : _should_add_to_response(should_add_to_response){}
|
|
bool operator()() const noexcept {
|
|
return _should_add_to_response;
|
|
}
|
|
|
|
consumed_capacity_counter& operator +=(uint64_t bytes);
|
|
double get_consumed_capacity_units() const noexcept;
|
|
void add_consumed_capacity_to_response_if_needed(rjson::value& response) const noexcept;
|
|
virtual ~consumed_capacity_counter() = default;
|
|
/**
|
|
* \brief get_half_units calculate the half units from the total bytes based on the type of the request
|
|
*/
|
|
virtual uint64_t get_half_units() const noexcept = 0;
|
|
uint64_t _total_bytes = 0;
|
|
static bool should_add_capacity(const rjson::value& request);
|
|
protected:
|
|
bool _should_add_to_response = false;
|
|
};
|
|
|
|
class rcu_consumed_capacity_counter : public consumed_capacity_counter {
|
|
bool _is_quorum = false;
|
|
public:
|
|
rcu_consumed_capacity_counter(const rjson::value& request, bool is_quorum);
|
|
rcu_consumed_capacity_counter(): consumed_capacity_counter(false), _is_quorum(false){}
|
|
virtual uint64_t get_half_units() const noexcept;
|
|
static uint64_t get_half_units(uint64_t total_bytes, bool is_quorum) noexcept;
|
|
};
|
|
|
|
class wcu_consumed_capacity_counter : public consumed_capacity_counter {
|
|
virtual uint64_t get_half_units() const noexcept;
|
|
public:
|
|
wcu_consumed_capacity_counter(const rjson::value& request);
|
|
static uint64_t get_units(uint64_t total_bytes) noexcept;
|
|
};
|
|
|
|
}
|