polybar/include/utils/throttle.hpp

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#pragma once
#include <deque>
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#include <chrono>
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#include "common.hpp"
#include "components/logger.hpp"
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POLYBAR_NS
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namespace chrono = std::chrono;
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namespace throttle_util {
using timewindow = chrono::duration<double, std::milli>;
using timepoint_clock = chrono::high_resolution_clock;
using timepoint = timepoint_clock::time_point;
using queue = std::deque<timepoint>;
using limit = size_t;
namespace strategy {
struct try_once_or_leave_yolo {
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bool operator()(queue& q, limit l, timewindow);
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};
struct wait_patiently_by_the_door {
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bool operator()(queue& q, limit l, timewindow);
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};
}
/**
* Throttle events within a set window of time
*
* Example usage:
* @code cpp
* auto t = throttle_util::make_throttler(2, 1s);
* if (t->passthrough())
* ...
* @endcode
*/
class event_throttler {
public:
/**
* Construct throttler
*/
explicit event_throttler(int limit, timewindow timewindow)
: m_limit(limit), m_timewindow(timewindow) {}
/**
* Check if event is allowed to pass
* using specified strategy
*/
template <typename Strategy>
bool passthrough(Strategy wait_strategy) {
expire_timestamps();
return wait_strategy(m_queue, m_limit, m_timewindow);
}
/**
* Check if event is allowed to pass
* using default strategy
*/
bool passthrough() {
return passthrough(strategy::try_once_or_leave_yolo{});
}
protected:
/**
* Expire old timestamps
*/
void expire_timestamps() {
auto now = timepoint_clock::now();
while (m_queue.size() > 0) {
if ((now - m_queue.front()) < m_timewindow)
break;
m_queue.pop_front();
}
}
private:
queue m_queue;
limit m_limit;
timewindow m_timewindow;
};
using throttle_t = unique_ptr<event_throttler>;
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template <typename... Args>
throttle_t make_throttler(Args&&... args) {
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return make_unique<event_throttler>(forward<Args>(args)...);
}
}
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POLYBAR_NS_END