userver: userver/congestion_control/controller.hpp Source File
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controller.hpp
1#pragma once
2
3#include <atomic>
4#include <chrono>
5#include <cstddef>
6#include <optional>
7#include <string>
8
9#include <userver/congestion_control/limiter.hpp>
10#include <userver/congestion_control/sensor.hpp>
11#include <userver/dynamic_config/source.hpp>
12#include <userver/formats/json_fwd.hpp>
13
14#include <dynamic_config/variables/USERVER_RPS_CCONTROL.hpp>
15
16USERVER_NAMESPACE_BEGIN
17
18/// Congestion Control
19namespace congestion_control {
20
22 size_t times_with_overload{0};
23 size_t times_wo_overload{0};
24
25 bool is_overloaded{false};
26 std::optional<size_t> current_limit;
27
28 size_t max_up_delta{1};
29};
30
31struct Stats final {
32 std::atomic<size_t> no_limit{0};
33 std::atomic<size_t> not_overload_no_pressure{0};
34 std::atomic<size_t> not_overload_pressure{0};
35 std::atomic<size_t> overload_no_pressure{0};
36 std::atomic<size_t> overload_pressure{0};
37
38 std::atomic<size_t> current_state{0};
39 std::atomic<std::chrono::seconds> last_overload_pressure{
40 std::chrono::duration_cast<std::chrono::seconds>(std::chrono::steady_clock::now().time_since_epoch()) -
41 std::chrono::hours(1)};
42};
43
44using Policy = ::dynamic_config::userver_rps_ccontrol::VariableType;
45
46class Controller final {
47public:
48 Controller(std::string name, dynamic_config::Source config_source);
49
50 void Feed(const Sensor::Data&);
51
52 Limit GetLimit() const;
53
54 Limit GetLimitRaw() const;
55
56 void SetEnabled(bool enabled);
57
58 bool IsEnabled() const;
59
60 const Stats& GetStats() const;
61
62private:
63 bool IsOverloadedNow(const Sensor::Data& data, const Policy& policy) const;
64
65 size_t CalcNewLimit(const Sensor::Data& data, const Policy& policy) const;
66
67 static bool IsThresholdReached(const Sensor::Data& data, int percent);
68
69 const std::string name_;
70 Limit limit_;
71 dynamic_config::Source config_source_;
72 PolicyState state_;
73 std::atomic<bool> is_enabled_;
74
75 Stats stats_;
76};
77
79 Sensor& sensor;
80 Limiter& limiter;
81 Controller& controller;
82};
83
84} // namespace congestion_control
85
86USERVER_NAMESPACE_END