scotty/pkg/ratelimit/httpheader.go
2024-01-12 17:24:05 +01:00

61 lines
2 KiB
Go

/*
Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
Scotty is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later version.
Scotty is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
Scotty. If not, see <https://www.gnu.org/licenses/>.
*/
package ratelimit
import (
"net/http"
"strconv"
"time"
"github.com/go-resty/resty/v2"
)
const (
RetryCount = 5
DefaultRateLimitWaitSeconds = 5
MaxWaitTimeSeconds = 60
)
// Implements rate HTTP header based limiting for resty.
//
// This works with servers that return the status code 429 (Too Many Requests)
// and an HTTP header indicating the time in seconds until rate limit resets.
// Common headers used are "X-RateLimit-Reset-In" or "Retry-After".
//
// Usage:
//
// ratelimit.EnableHTTPHeaderRateLimit(client, "Retry-After")
func EnableHTTPHeaderRateLimit(client *resty.Client, resetInHeader string) {
client.SetRetryCount(RetryCount)
client.AddRetryCondition(
func(r *resty.Response, err error) bool {
code := r.StatusCode()
return code == http.StatusTooManyRequests || code >= http.StatusInternalServerError
},
)
client.SetRetryMaxWaitTime(time.Duration(MaxWaitTimeSeconds * time.Second))
client.SetRetryAfter(func(client *resty.Client, resp *resty.Response) (time.Duration, error) {
var err error
var retryAfter int = DefaultRateLimitWaitSeconds
if resp.StatusCode() == http.StatusTooManyRequests {
retryAfter, err = strconv.Atoi(resp.Header().Get(resetInHeader))
if err != nil {
retryAfter = DefaultRateLimitWaitSeconds
}
}
return time.Duration(retryAfter * int(time.Second)), err
})
}