34 lines
861 B
C++
34 lines
861 B
C++
/*
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* Copyright 2015 Cloudius Systems
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*/
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#include "rate_limiter.hh"
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utils::rate_limiter::rate_limiter(size_t rate)
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: _units_per_s(rate) {
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if (_units_per_s != 0) {
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_timer.set_callback(std::bind(&rate_limiter::on_timer, this));
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_timer.arm(lowres_clock::now() + std::chrono::seconds(1),
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std::experimental::optional<lowres_clock::duration> {
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std::chrono::seconds(1) });
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}
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}
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void utils::rate_limiter::on_timer() {
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_sem.signal(_units_per_s - _sem.current());
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}
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future<> utils::rate_limiter::reserve(size_t u) {
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if (_units_per_s == 0) {
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return make_ready_future<>();
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}
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if (u <= _units_per_s) {
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return _sem.wait(u);
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}
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auto n = std::min(u, _units_per_s);
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auto r = u - n;
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return _sem.wait(n).then([this, r] {
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return reserve(r);
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});
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}
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