pcgamedb/utils/fetch.go
2024-09-24 18:17:11 +08:00

179 lines
3.9 KiB
Go

package utils
import (
"bytes"
"context"
"encoding/json"
"errors"
"io"
"net"
"net/http"
"net/url"
"strings"
"time"
"golang.org/x/net/html/charset"
)
const userAgent string = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36"
type FetchConfig struct {
Method string
Url string
Data interface{}
RetryTimes int
Headers map[string]string
Cookies map[string]string
}
type FetchResponse struct {
StatusCode int
Data []byte
Header http.Header
Cookie []*http.Cookie
}
func Fetch(cfg FetchConfig) (*FetchResponse, error) {
var req *http.Request
var resp *http.Response
var backoff time.Duration = 1
var reqBody io.Reader = nil
var err error
if cfg.RetryTimes == 0 {
cfg.RetryTimes = 3
}
if cfg.Method == "" {
cfg.Method = "GET"
}
if cfg.Data != nil && (cfg.Method == "POST" || cfg.Method == "PUT") {
if cfg.Headers == nil {
cfg.Headers = map[string]string{}
}
if _, exist := cfg.Headers["Content-Type"]; !exist {
cfg.Headers["Content-Type"] = "application/json"
}
v := cfg.Headers["Content-Type"]
if v == "application/x-www-form-urlencoded" {
switch data := cfg.Data.(type) {
case map[string]string:
params := url.Values{}
for k, v := range data {
params.Set(k, v)
}
reqBody = strings.NewReader(params.Encode())
case string:
reqBody = strings.NewReader(data)
case url.Values:
reqBody = strings.NewReader(data.Encode())
default:
return nil, errors.New("unsupported data type")
}
} else if v == "application/json" {
var jsonData []byte
jsonData, err = json.Marshal(cfg.Data)
if err != nil {
return nil, err
}
reqBody = bytes.NewReader(jsonData)
} else {
reqBody = strings.NewReader(cfg.Data.(string))
}
}
for retryTime := 0; retryTime <= cfg.RetryTimes; retryTime++ {
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
req, err = http.NewRequestWithContext(ctx, cfg.Method, cfg.Url, reqBody)
if err != nil {
return nil, err
}
if cfg.Method == "POST" || cfg.Method == "PUT" {
req.Header.Set("Content-Type", "application/json")
}
if v, exist := cfg.Headers["User-Agent"]; exist {
if v != "" {
req.Header.Set("User-Agent", v)
}
} else {
req.Header.Set("User-Agent", userAgent)
}
for k, v := range cfg.Headers {
req.Header.Set(k, v)
}
for k, v := range cfg.Cookies {
req.AddCookie(&http.Cookie{Name: k, Value: v})
}
resp, err = http.DefaultClient.Do(req)
if err != nil {
if isRetryableError(err) {
err = errors.New("request error: " + err.Error())
time.Sleep(backoff * time.Second)
backoff *= 2
continue
}
}
if resp == nil {
return nil, errors.New("response is nil")
}
if isRetryableStatusCode(resp.StatusCode) {
err = errors.New("response status code: " + resp.Status)
time.Sleep(backoff * time.Second)
backoff *= 2
continue
}
contentType := resp.Header.Get("Content-Type")
var reader io.Reader
if strings.Contains(contentType, "charset=") {
reader, err = charset.NewReader(resp.Body, contentType)
} else {
reader = resp.Body
}
if err != nil {
return nil, err
}
dataBytes, err := io.ReadAll(reader)
if err != nil {
return nil, err
}
res := &FetchResponse{
StatusCode: resp.StatusCode,
Header: resp.Header,
Cookie: resp.Cookies(),
Data: dataBytes,
}
return res, nil
}
return nil, err
}
func isRetryableStatusCode(statusCode int) bool {
switch statusCode {
case http.StatusInternalServerError,
http.StatusBadGateway,
http.StatusServiceUnavailable,
http.StatusGatewayTimeout,
http.StatusTooManyRequests:
return true
default:
return false
}
}
func isRetryableError(err error) bool {
if err != nil {
var netErr net.Error
if errors.As(err, &netErr) && netErr.Timeout() {
return true
}
}
return false
}