mirror of
https://github.com/cubefs/cubefs.git
synced 2026-08-02 18:15:51 +00:00
123 lines
2.6 KiB
Go
123 lines
2.6 KiB
Go
// Copyright 2023 The CubeFS Authors.
|
|
//
|
|
// Licensed 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.
|
|
|
|
// Package ratelimit RateLimit Algorithm Based on Token Bucket
|
|
package flowctrl
|
|
|
|
import (
|
|
"io"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
tokenWindow = 50 * time.Millisecond
|
|
minWindowCap = 64
|
|
)
|
|
|
|
type Controller struct {
|
|
capacity int
|
|
threshold int
|
|
cond *sync.Cond
|
|
done chan struct{}
|
|
ratePerSecond int
|
|
closeOnce *sync.Once
|
|
}
|
|
|
|
func NewController(ratePerSecond int) *Controller {
|
|
capacity := ratePerSecond * int(tokenWindow) / int(time.Second)
|
|
if capacity < minWindowCap {
|
|
capacity = minWindowCap
|
|
}
|
|
self := &Controller{
|
|
ratePerSecond: ratePerSecond,
|
|
threshold: capacity,
|
|
capacity: capacity,
|
|
cond: sync.NewCond(new(sync.Mutex)),
|
|
done: make(chan struct{}, 1),
|
|
closeOnce: &sync.Once{},
|
|
}
|
|
// produce token asynchronously
|
|
go self.run(capacity)
|
|
return self
|
|
}
|
|
|
|
func (self *Controller) acquire(size int) int {
|
|
self.cond.L.Lock()
|
|
for self.capacity == 0 {
|
|
self.cond.Wait()
|
|
}
|
|
if size > self.capacity {
|
|
size = self.capacity
|
|
}
|
|
self.capacity -= size
|
|
self.cond.L.Unlock()
|
|
return size
|
|
}
|
|
|
|
func (self *Controller) fill(size int) {
|
|
if size <= 0 {
|
|
return
|
|
}
|
|
self.cond.L.Lock()
|
|
self.capacity += size
|
|
if self.capacity > self.threshold {
|
|
self.capacity = self.threshold
|
|
}
|
|
self.cond.L.Unlock()
|
|
self.cond.Broadcast()
|
|
}
|
|
|
|
func (self *Controller) run(capacity int) {
|
|
t := time.NewTicker(tokenWindow)
|
|
for {
|
|
select {
|
|
case <-t.C:
|
|
self.cond.L.Lock()
|
|
self.capacity = capacity
|
|
self.cond.L.Unlock()
|
|
self.cond.Broadcast()
|
|
case <-self.done:
|
|
t.Stop()
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// Close release token-producing goroutine
|
|
func (self *Controller) Close() error {
|
|
self.closeOnce.Do(func() {
|
|
self.done <- struct{}{}
|
|
})
|
|
return nil
|
|
}
|
|
|
|
func (self *Controller) Reader(underlying io.Reader) io.Reader {
|
|
return &rateReader{
|
|
underlying: underlying,
|
|
c: self,
|
|
}
|
|
}
|
|
|
|
func (self *Controller) Writer(underlying io.Writer) io.Writer {
|
|
return &rateWriter{
|
|
underlying: underlying,
|
|
c: self,
|
|
}
|
|
}
|
|
|
|
func (self *Controller) GetRateLimit() int {
|
|
return self.ratePerSecond
|
|
}
|
