38a54df863
People keep tripping over the old copyrights and copy-pasting them to new files. Search and replace "Cloudius Systems" with "ScyllaDB". Message-Id: <1460013664-25966-1-git-send-email-penberg@scylladb.com>
51 lines
1.5 KiB
C++
51 lines
1.5 KiB
C++
/*
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* Copyright (C) 2015 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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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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