/
httpClient.go
49 lines (43 loc) · 1.31 KB
/
httpClient.go
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// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License"). You may
// not use this file except in compliance with the License. A copy of the
// License is located at
//
// http://aws.amazon.com/apache2.0/
//
// or in the "license" file accompanying this file. This file 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 utils
import (
"fmt"
"net/http"
"golang.org/x/time/rate"
)
// NewRateLimitedClient returns a new HTTP client with rate limiter.
func NewRateLimitedClient(qps int, burst int) (*http.Client, error) {
if qps == 0 {
return http.DefaultClient, nil
}
if burst < 1 {
return nil, fmt.Errorf("burst expected >0, got %d", burst)
}
return &http.Client{
Transport: &rateLimitedRoundTripper{
rt: http.DefaultTransport,
rl: rate.NewLimiter(rate.Limit(qps), burst),
},
}, nil
}
type rateLimitedRoundTripper struct {
rt http.RoundTripper
rl *rate.Limiter
}
func (rr *rateLimitedRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
if err := rr.rl.Wait(req.Context()); err != nil {
return nil, err
}
return rr.rt.RoundTrip(req)
}