图片生成 API 返回的 base64 内联图响应经常超过 8MB 单次读取上限,被 ReadUpstreamResponseBody 拦截成 502 upstream_error。 单张 4K PNG base64 最坏约 67MB,多张候选图或 imageSize=4K 的 image_generation 一次请求能轻松到 30MB+。把默认上限提到 128MB 能覆盖 2-3 张 4K 图,相对 请求体上限 256MB 仍有缓冲;同时抽出 config.DefaultUpstreamResponseReadMaxBytes 共享常量,viper 默认值和 service 层兜底共用,消除两处同步魔法数字。 仍可通过 gateway.upstream_response_read_max_bytes 配置项覆盖。
84 lines
2.4 KiB
Go
84 lines
2.4 KiB
Go
package service
|
||
|
||
import (
|
||
"errors"
|
||
"fmt"
|
||
"io"
|
||
"net/http"
|
||
|
||
"github.com/Wei-Shaw/sub2api/internal/config"
|
||
"github.com/gin-gonic/gin"
|
||
)
|
||
|
||
var ErrUpstreamResponseBodyTooLarge = errors.New("upstream response body too large")
|
||
|
||
// defaultUpstreamResponseReadMaxBytes 源自 config.DefaultUpstreamResponseReadMaxBytes,
|
||
// 仅在 cfg 为 nil 时作为兜底(测试或极端场景)。
|
||
const defaultUpstreamResponseReadMaxBytes = config.DefaultUpstreamResponseReadMaxBytes
|
||
|
||
func resolveUpstreamResponseReadLimit(cfg *config.Config) int64 {
|
||
if cfg != nil && cfg.Gateway.UpstreamResponseReadMaxBytes > 0 {
|
||
return cfg.Gateway.UpstreamResponseReadMaxBytes
|
||
}
|
||
return defaultUpstreamResponseReadMaxBytes
|
||
}
|
||
|
||
func readUpstreamResponseBodyLimited(reader io.Reader, maxBytes int64) ([]byte, error) {
|
||
if reader == nil {
|
||
return nil, errors.New("response body is nil")
|
||
}
|
||
if maxBytes <= 0 {
|
||
maxBytes = defaultUpstreamResponseReadMaxBytes
|
||
}
|
||
|
||
body, err := io.ReadAll(io.LimitReader(reader, maxBytes+1))
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
if int64(len(body)) > maxBytes {
|
||
return nil, fmt.Errorf("%w: limit=%d", ErrUpstreamResponseBodyTooLarge, maxBytes)
|
||
}
|
||
return body, nil
|
||
}
|
||
|
||
// TooLargeWriter 在响应超限时向客户端写格式化的错误响应。
|
||
type TooLargeWriter func(c *gin.Context)
|
||
|
||
// ReadUpstreamResponseBody 读取上游非流式响应体。
|
||
// 超限时自动记录 ops error 并调用 onTooLarge 向客户端写错误。
|
||
func ReadUpstreamResponseBody(reader io.Reader, cfg *config.Config, c *gin.Context, onTooLarge TooLargeWriter) ([]byte, error) {
|
||
maxBytes := resolveUpstreamResponseReadLimit(cfg)
|
||
body, err := readUpstreamResponseBodyLimited(reader, maxBytes)
|
||
if err != nil {
|
||
if errors.Is(err, ErrUpstreamResponseBodyTooLarge) {
|
||
setOpsUpstreamError(c, http.StatusBadGateway, "upstream response too large", "")
|
||
if onTooLarge != nil {
|
||
onTooLarge(c)
|
||
}
|
||
}
|
||
return nil, err
|
||
}
|
||
return body, nil
|
||
}
|
||
|
||
// anthropicTooLargeError 以 Anthropic Messages API 格式写入超限错误。
|
||
func anthropicTooLargeError(c *gin.Context) {
|
||
c.JSON(http.StatusBadGateway, gin.H{
|
||
"type": "error",
|
||
"error": gin.H{
|
||
"type": "upstream_error",
|
||
"message": "Upstream response too large",
|
||
},
|
||
})
|
||
}
|
||
|
||
// openAITooLargeError 以 OpenAI / Gemini 格式写入超限错误。
|
||
func openAITooLargeError(c *gin.Context) {
|
||
c.JSON(http.StatusBadGateway, gin.H{
|
||
"error": gin.H{
|
||
"type": "upstream_error",
|
||
"message": "Upstream response too large",
|
||
},
|
||
})
|
||
}
|