71 lines
1.8 KiB
Go
71 lines
1.8 KiB
Go
package handler
|
||
|
||
import (
|
||
"bytes"
|
||
"errors"
|
||
"io"
|
||
"mime"
|
||
"net/http"
|
||
"strings"
|
||
|
||
"github.com/gin-gonic/gin"
|
||
)
|
||
|
||
var errSystemProxyResponseTooLarge = errors.New("系统渠道流式响应超过配置上限")
|
||
|
||
func isSystemProxyEventStream(resp *http.Response) bool {
|
||
mediaType, _, err := mime.ParseMediaType(resp.Header.Get("Content-Type"))
|
||
return err == nil && strings.EqualFold(mediaType, "text/event-stream")
|
||
}
|
||
|
||
func copySystemProxyResponseHeaders(c *gin.Context, resp *http.Response) {
|
||
for _, key := range []string{"Content-Type", "Cache-Control", "Content-Disposition"} {
|
||
if value := resp.Header.Get(key); value != "" {
|
||
c.Header(key, value)
|
||
}
|
||
}
|
||
c.Header("X-Content-Type-Options", "nosniff")
|
||
}
|
||
|
||
func streamSystemProxyResponse(c *gin.Context, resp *http.Response, responseLimit int64) ([]byte, error) {
|
||
copySystemProxyResponseHeaders(c, resp)
|
||
// 同时通知镜像内和可能存在的外层 Nginx，不得重新缓冲模型事件流。
|
||
c.Header("Cache-Control", "no-cache, no-store, no-transform")
|
||
c.Header("X-Accel-Buffering", "no")
|
||
c.Status(resp.StatusCode)
|
||
c.Writer.WriteHeaderNow()
|
||
c.Writer.Flush()
|
||
|
||
var captured bytes.Buffer
|
||
buffer := make([]byte, 32<<10)
|
||
remaining := responseLimit
|
||
for {
|
||
readLimit := int64(len(buffer))
|
||
if remaining < readLimit {
|
||
readLimit = remaining + 1
|
||
}
|
||
if readLimit < 1 {
|
||
readLimit = 1
|
||
}
|
||
read, readErr := resp.Body.Read(buffer[:int(readLimit)])
|
||
if read > 0 {
|
||
if int64(read) > remaining {
|
||
return captured.Bytes(), errSystemProxyResponseTooLarge
|
||
}
|
||
chunk := buffer[:read]
|
||
_, _ = captured.Write(chunk)
|
||
if _, writeErr := c.Writer.Write(chunk); writeErr != nil {
|
||
return captured.Bytes(), writeErr
|
||
}
|
||
c.Writer.Flush()
|
||
remaining -= int64(read)
|
||
}
|
||
if readErr != nil {
|
||
if errors.Is(readErr, io.EOF) {
|
||
return captured.Bytes(), nil
|
||
}
|
||
return captured.Bytes(), readErr
|
||
}
|
||
}
|
||
}
|