frp/pkg/util/limit/writer.go

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2019-11-03 01:20:49 +08:00
// Copyright 2019 fatedier, fatedier@gmail.com
//
// 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 limit
import (
"context"
"io"
"golang.org/x/time/rate"
)
type Writer struct {
w io.Writer
limiter *rate.Limiter
}
func NewWriter(w io.Writer, limiter *rate.Limiter) *Writer {
return &Writer{
w: w,
limiter: limiter,
}
}
func (w *Writer) Write(p []byte) (n int, err error) {
var nn int
b := w.limiter.Burst()
for {
end := len(p)
if end == 0 {
break
}
if b < len(p) {
end = b
}
err = w.limiter.WaitN(context.Background(), end)
if err != nil {
return
}
nn, err = w.w.Write(p[:end])
n += nn
if err != nil {
return
}
p = p[end:]
}
return
}