| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| #include "kudu/util/throttler.h" |
| |
| #include <algorithm> |
| #include <mutex> |
| |
| namespace kudu { |
| |
| Throttler::Throttler(MonoTime now, uint64_t op_rate, uint64_t byte_rate, double burst_factor) : |
| next_refill_(now) { |
| op_refill_ = op_rate / (MonoTime::kMicrosecondsPerSecond / kRefillPeriodMicros); |
| op_token_ = 0; |
| op_token_max_ = static_cast<uint64_t>(op_refill_ * burst_factor); |
| byte_refill_ = byte_rate / (MonoTime::kMicrosecondsPerSecond / kRefillPeriodMicros); |
| byte_token_ = 0; |
| byte_token_max_ = static_cast<uint64_t>(byte_refill_ * burst_factor); |
| } |
| |
| bool Throttler::Take(MonoTime now, uint64_t op, uint64_t byte) { |
| if (op_refill_ == 0 && byte_refill_ == 0) { |
| return true; |
| } |
| std::lock_guard<simple_spinlock> lock(lock_); |
| Refill(now); |
| if ((op_refill_ == 0 || op <= op_token_) && |
| (byte_refill_ == 0 || byte <= byte_token_)) { |
| if (op_refill_ > 0) { |
| op_token_ -= op; |
| } |
| if (byte_refill_ > 0) { |
| byte_token_ -= byte; |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| void Throttler::Refill(MonoTime now) { |
| int64_t d = (now - next_refill_).ToMicroseconds(); |
| if (d < 0) { |
| return; |
| } |
| uint64_t num_period = d / kRefillPeriodMicros + 1; |
| next_refill_ += MonoDelta::FromMicroseconds(num_period * kRefillPeriodMicros); |
| op_token_ += num_period * op_refill_; |
| op_token_ = std::min(op_token_, op_token_max_); |
| byte_token_ += num_period * byte_refill_; |
| byte_token_ = std::min(byte_token_, byte_token_max_); |
| } |
| |
| } // namespace kudu |