sensor.hpp

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#pragma once
 
/// @file userver/congestion_control/sensor.hpp
/// @brief Congestion control sensor interfaces
 
#include <chrono>
#include <cstdint>
#include <string>
#include <unordered_map>
 
USERVER_NAMESPACE_BEGIN
 
namespace congestion_control {
 
/// Abstract sensor that fetches counters. These counters will be used
/// to forecast saturation levels and limit current load.
class Sensor {
public:
    struct Data {
        std::uint64_t current_load{0};
        std::uint64_t overload_events_count{0};
        std::uint64_t no_overload_events_count{0};
        std::chrono::steady_clock::time_point tp;
 
        double GetLoadPercent() const;
    };
 
    virtual ~Sensor() = default;
 
    /// @brief Fetch current counters
    /// @note Can be called both from coroutine and non-coroutine context
    virtual Data FetchCurrent() = 0;
};
 
namespace v2 {
 
class Sensor {
public:
    struct SingleObjectData {
        static constexpr auto kCommonObjectName = "common";
 
        std::size_t total{0};
        std::size_t timeouts{0};
        std::size_t timings_sum_ms{0};
 
        double GetRate() const { return static_cast<double>(timeouts) / (total ? total : 1); }
        std::string ToLogString() const;
    };
 
    struct Data {
        std::unordered_map<std::string, SingleObjectData> objects;
        std::size_t current_load{0};
    };
 
    virtual ~Sensor() = default;
 
    virtual Data GetCurrent() = 0;
};
 
}  // namespace v2
 
}  // namespace congestion_control
 
USERVER_NAMESPACE_END