nacos-sdk-go/clients/config_client/limiter.go

56 lines
1.5 KiB
Go

/*
* Copyright 1999-2020 Alibaba Group Holding Ltd.
*
* 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 config_client
import (
"sync"
"time"
"github.com/nacos-group/nacos-sdk-go/v2/clients/cache"
"golang.org/x/time/rate"
)
type rateLimiterCheck struct {
rateLimiterCache cache.ConcurrentMap // cache
mux sync.Mutex
}
var checker rateLimiterCheck
func init() {
checker = rateLimiterCheck{
rateLimiterCache: cache.NewConcurrentMap(),
mux: sync.Mutex{},
}
}
// IsLimited return true when request is limited
func IsLimited(checkKey string) bool {
checker.mux.Lock()
defer checker.mux.Unlock()
var limiter *rate.Limiter
lm, exist := checker.rateLimiterCache.Get(checkKey)
if !exist {
// define a new limiter,allow 5 times per second,and reserve stock is 5.
limiter = rate.NewLimiter(rate.Limit(5), 5)
checker.rateLimiterCache.Set(checkKey, limiter)
} else {
limiter = lm.(*rate.Limiter)
}
add := time.Now().Add(time.Second)
return !limiter.AllowN(add, 1)
}