Files
openteam/server/internal/proxy/passthrough.go
T
Sakurasan 979973ddde feat: 流式首包缓冲容错(hold)与失败分类冷却
流式请求在首个内容事件到达前由网关缓冲(借鉴 magpie 的 holdWriter):上游的错误
事件、空流、断连、协议形态不符(要流给了整包)都在放行前换渠道消化,客户端无感知。
扣住期间照常发 SSE 注释心跳;缓冲超过 1MB 直接放行退化为普通转发,判定失效不吞正文。

- 新增 proxy/hold.go:streamHold(缓冲/放行/心跳/首 token 计时与放行互斥)、
  sseEventHasContent(chat/messages/responses 三种协议的内容判定)、
  sseUpstreamError(200+流式形式的错误事件识别)、classifyUpstreamError +
  quotaSignals(余额/配额特征识别)
- 非流式改为先读完整响应再写头:读失败(网络错误/超时)发生在写出之前,可换渠道
  重试;此前先写 200 头再读,超时只能给客户端留一个 200 空响应
- 协议形态校验:要流却给了整包(didNotStream)按失败换渠道,反复如此的渠道会被
  健康计数剔除
- 记账:每次尝试独立 trySink,只有成功走到 EOF 才并入请求级 sink——失败渠道的
  message_start 用量不计入账单
- 冷却按原因分类(channel.FailKind):余额/配额类第一次失败即冷却 30 分钟(429 不
  一定是限流,智谱 429「余额不足」也在此列);其余按连续进冷却次数指数退避
  30s→60s→120s,封顶 10 分钟;短于退避值的 Retry-After 不再缩短冷却
- 新增 OT_PROXY_FIRST_TOKEN_WAIT(默认 0=不限):放行前等内容的最长时间,超时即
  取消本次尝试换下一个渠道
- 渠道列表接口返回 cooldown_reason,后台可区分「限流」与「余额耗尽」
- 测试:hold 缓冲/放行/心跳、内容与错误事件判定、失败分类与指数退避、容量热生效
- docs/magpie-plugin-mechanism.md:参考实现的插件机制调研
2026-10-30 02:43:23 +08:00

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package proxy
import (
"bufio"
"bytes"
"context"
"crypto/rand"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"io"
"log"
"net/http"
"strconv"
"strings"
"time"
"github.com/gin-gonic/gin"
"github.com/openteam/server/internal/channel"
"github.com/openteam/server/internal/pkg/tokenizer"
"github.com/openteam/server/internal/proxy/convert"
"github.com/openteam/server/internal/store"
)
// newTraceID 生成请求 trace(用于日志与记账幂等 ref)。
func newTraceID() string {
b := make([]byte, 8)
_, _ = rand.Read(b)
return hex.EncodeToString(b)
}
// bodyReq 统一取出请求体并解析 model / stream 字段。
type bodyReq struct {
Model string `json:"model"`
Stream bool `json:"stream"`
}
// parseBody 读取并回填请求体,解析 model/stream。
func parseBody(c *gin.Context) (*bodyReq, []byte, error) {
body, err := io.ReadAll(c.Request.Body)
if err != nil {
return nil, nil, err
}
c.Request.Body = io.NopCloser(bytes.NewReader(body))
// 中断请求输入文本(token 估算用,仅存文本不立即分词)
c.Set("est_input_text", requestText(body))
br := &bodyReq{}
_ = json.Unmarshal(body, br) // 解析失败按空处理,直通仍可转发
return br, body, nil
}
// requestText 提取请求体中的用户输入文本(chat/messages 的 content、responses 的 input/instructions),
// 用于中断时估算输入 token。
func requestText(body []byte) string {
var m map[string]any
if json.Unmarshal(body, &m) != nil {
return ""
}
var parts []string
add := func(s string) {
if s = strings.TrimSpace(s); s != "" {
parts = append(parts, s)
}
}
if s, ok := m["instructions"].(string); ok {
add(s)
}
if s, ok := m["system"].(string); ok {
add(s)
}
switch input := m["input"].(type) {
case string:
add(input)
case []any:
for _, it := range input {
if im, ok := it.(map[string]any); ok {
if s, ok := im["content"].(string); ok {
add(s)
}
}
}
}
if msgs, ok := m["messages"].([]any); ok {
for _, msg := range msgs {
mm, ok := msg.(map[string]any)
if !ok {
continue
}
switch c := mm["content"].(type) {
case string:
add(c)
case []any:
for _, b := range c {
if bm, ok := b.(map[string]any); ok {
if s, ok := bm["text"].(string); ok {
add(s)
}
}
}
}
}
}
return strings.Join(parts, "\n")
}
// sseDataPayload 提取一条 SSE 的 JSON 载荷(去掉 data: 前缀与空白)。
// 兼容三种写法:
// - 单 data: 行:data: {...} 或 data:{...}(上游如火山方舟会省略 data: 后的空格)
// - event:+data: 多行块:转换器 eventLine 产出的块(event: xxx\ndata: {...} 拼在一个 []byte)
func sseDataPayload(line []byte) (string, bool) {
s := string(line)
idx := strings.LastIndex(s, "\ndata:")
if idx >= 0 {
s = s[idx+len("\ndata:"):] // 跳过 event: 头,落在 data: 之后
} else if strings.HasPrefix(s, "data:") {
s = strings.TrimPrefix(s, "data:")
} else {
return "", false
}
s = strings.TrimLeft(s, " ") // data: 后的可选空格
s = strings.TrimSpace(s)
if s == "" || s == "[DONE]" {
return "", false
}
return s, true
}
// sseContentText 提取一条 SSE 中的内容文本(chat delta.content / responses delta / messages delta.text)。
func sseContentText(line []byte) string {
s, ok := sseDataPayload(line)
if !ok {
return ""
}
var m map[string]any
if json.Unmarshal([]byte(s), &m) != nil {
return ""
}
// responses output_text.delta: {"delta":"..."}
if d, ok := m["delta"].(string); ok {
return d
}
// messages content_block_delta: {"delta":{"text":"..."}}
if dm, ok := m["delta"].(map[string]any); ok {
if t, ok := dm["text"].(string); ok {
return t
}
}
// chat chunk: {"choices":[{"delta":{"content":"..."}}]}(GLM 思考模型另有 reasoning_content)
if choices, ok := m["choices"].([]any); ok && len(choices) > 0 {
if c0, ok := choices[0].(map[string]any); ok {
if delta, ok := c0["delta"].(map[string]any); ok {
if t, ok := delta["content"].(string); ok {
return t
}
if t, ok := delta["reasoning_content"].(string); ok {
return t
}
}
}
}
return ""
}
// retryAfter 解析上游 Retry-After(delta-秒或 HTTP 日期),用于按对端意愿延长渠道冷却。
// 解析不出或为非正返回 0,交给 channel.Service 用默认时长(并夹到上限)。
func retryAfter(h http.Header) time.Duration {
v := strings.TrimSpace(h.Get("Retry-After"))
if v == "" {
return 0
}
if secs, err := strconv.Atoi(v); err == nil {
if secs <= 0 {
return 0
}
return time.Duration(secs) * time.Second
}
if t, err := http.ParseTime(v); err == nil {
if d := time.Until(t); d > 0 {
return d
}
}
return 0
}
// upstreamURL 组装上游地址:按协议选 base_url 再拼资源路径(见 store.Channel.UpstreamURL)。
func upstreamURL(ch *store.Channel, proto, path string) string {
return ch.UpstreamURL(proto, path)
}
// doProxy 通用代理(M5):加权随机选一个候选渠道;失败自动故障转移。
// 流式请求挂一条 streamHold:首个内容事件到达之前,上游的错误/空流/断连都还能
// 换渠道消化,客户端无感知(借鉴 magpie 的 holdWriter)。
func (g *Gateway) doProxy(c *gin.Context, cands []channel.Candidate, clientProto string, body []byte, stream bool, sink *usageSink) {
if len(cands) == 0 {
apiError(c, http.StatusBadGateway, "upstream_error", "no available channel")
g.recordError(c, nil, nil, now(), "no_available_channel")
return
}
// 加权随机选择起始渠道
picked := g.ch.Pick(cands)
startIdx := 0
for i, cand := range cands {
if cand.Channel.ID == picked.ID {
startIdx = i
break
}
}
// 流式容错缓冲 + 心跳,整条请求一条,跨渠道重试共用
var sh *streamHold
stopHB := func() {}
if stream {
sh = newStreamHold(c)
stopHB = sh.heartbeat(g.streamHeartbeat)
defer stopHB()
}
var lastStatus = http.StatusBadGateway
var lastBody = []byte("all upstream channels failed")
// 最后真正试过的渠道:全部失败时把错误归到它头上,否则 usage_logs 里
// channel_id=0,渠道维度的统计与排障就看不到这类失败。
var lastCh *store.Channel
startAll := time.Now()
// 从选中的渠道开始遍历,到末尾后再从头遍历到选中渠道之前
for offset := 0; offset < len(cands); offset++ {
// 重试预算只约束第二个及以后的渠道:首个渠道不受限(长回答本就要跑几分钟),
// 但坏渠道一个接一个地等下去会让客户端挂到 N×timeout。
if offset > 0 && g.failoverBudget > 0 && time.Since(startAll) > g.failoverBudget {
lastBody = []byte("failover budget exhausted: " + string(lastBody))
break
}
idx := (startIdx + offset) % len(cands)
cand := cands[idx]
ch := cand.Channel
// 客户端已断开:上游请求会随 context 立刻失败,换渠道也没有意义
if c.Request.Context().Err() != nil {
g.finishUsage(c, ch, now(), store.UsageStatusCanceled, "client_disconnect")
return
}
if g.ch.InCooldown(ch.ID) {
continue // 本次请求期间已被并发请求判入运行期冷却
}
plan, err := prepareUpstream(ch, clientProto, body, cand.UpstreamModel)
if err != nil {
// 请求体转换失败与渠道健康无关,不换渠道计数
lastStatus, lastBody = http.StatusInternalServerError, []byte("conversion error: "+err.Error())
continue
}
release, ok := g.ch.TryAcquire(ch)
if !ok {
continue // 渠道满载,溢出到下一个
}
// 失败/成功计数由 proxyOne 就地报:只有它读得到上游响应头(429 的 Retry-After)
lastCh = ch
done, retry, st, b := g.proxyOne(c, ch, plan, stream, sink, sh, clientProto)
release()
if done {
return
}
if !retry {
// 非重试性失败(如 400):透传上游错误体。
// 响应头若已被心跳先行写出,状态码不可再改,只能以 SSE 错误事件收尾。
if sh != nil && sh.headSent() {
_ = sh.writeDirect(streamErrorEvent(clientProto, st, string(b)))
g.recordError(c, ch, nil, now(), "upstream_http_"+strconv.Itoa(st))
return
}
c.Header("Content-Type", "application/json")
c.Data(st, "application/json", b)
g.recordError(c, ch, nil, now(), "upstream_http_"+strconv.Itoa(st))
return
}
lastStatus, lastBody = st, b
}
// 全部候选重试性失败
if sh != nil && sh.headSent() {
_ = sh.writeDirect(streamErrorEvent(clientProto, lastStatus, string(lastBody)))
g.recordError(c, lastCh, nil, now(), "all_channels_failed")
return
}
apiError(c, lastStatus, "upstream_error", string(lastBody))
g.recordError(c, lastCh, nil, now(), "all_channels_failed")
}
// streamErrorEvent 把错误构造成客户端协议的 SSE 错误事件(响应头已写出时的唯一交付方式)。
func streamErrorEvent(proto string, status int, msg string) []byte {
errObj := map[string]any{"message": msg, "type": "api_error", "code": "upstream_error", "status": status}
switch proto {
case convert.ProtoMessages:
body, _ := json.Marshal(map[string]any{"type": "error", "error": errObj})
return append([]byte("event: error\ndata: "), append(body, '\n', '\n')...)
case convert.ProtoResponses:
body, _ := json.Marshal(map[string]any{"type": "error", "code": "upstream_error", "message": msg})
return append([]byte("data: "), append(body, '\n', '\n')...)
default:
body, _ := json.Marshal(map[string]any{"error": errObj})
return append(append([]byte("data: "), append(body, '\n', '\n')...), []byte("data: [DONE]\n\n")...)
}
}
// proxyOne 对单个渠道执行一次代理。
// 返回:done=本次请求已终结(客户端响应已写出或已记账,停止故障转移);
// retry=是否可安全换渠道重试;status+respBody=失败信息。
// sh 为流式容错缓冲(非流式为 nil);sink 为请求级记账 sink。
func (g *Gateway) proxyOne(c *gin.Context, ch *store.Channel, plan *upstreamPlan, stream bool, sink *usageSink, sh *streamHold, clientProto string) (done bool, retry bool, status int, respBody []byte) {
upKey, err := g.ch.UpstreamKey(ch)
if err != nil {
g.ch.ReportFailure(ch, channel.FailNet, 0)
return false, true, http.StatusInternalServerError, []byte("failed to decrypt channel key")
}
upBody := plan.body
// 直通 chat 流式:注入 stream_options.include_usage,保证末块带 usage(OpenAI 行为)
if stream && plan.path == "/chat/completions" && plan.lineConv == nil && !bytes.Contains(upBody, []byte(`"include_usage"`)) {
var m map[string]any
if json.Unmarshal(upBody, &m) == nil {
m["stream_options"] = map[string]any{"include_usage": true}
if b, err := json.Marshal(m); err == nil {
upBody = b
}
}
}
// 上游请求绑定客户端 context:客户端断开即取消上游,不再空转生成、继续付费。
// 非流式再叠加渠道超时作为整段硬上限;流式只靠 Transport.ResponseHeaderTimeout
// 约束首包,正文时长不设限(长回答不能被超时砍断)。
limit := g.channelTimeout(ch)
ctx := c.Request.Context()
if !stream && limit > 0 {
var cancel context.CancelFunc
ctx, cancel = context.WithTimeout(ctx, limit)
defer cancel()
}
// 首 token 计时(可选):流式在放行前迟迟不出内容就取消本次尝试、换下一个渠道。
// 计时器与放行互斥(cancelIfHeld),已放行的健康流不会被掐死。
tryCtx := ctx
var tryCancel context.CancelFunc
var ftTimer *time.Timer
if stream && g.firstTokenWait > 0 {
tryCtx, tryCancel = context.WithCancel(ctx)
defer tryCancel()
ftTimer = time.AfterFunc(g.firstTokenWait, func() { sh.cancelIfHeld(tryCancel) })
defer ftTimer.Stop()
}
onRelease := func() {
if ftTimer != nil {
ftTimer.Stop()
}
}
req, err := http.NewRequestWithContext(tryCtx, http.MethodPost, upstreamURL(ch, plan.proto, plan.path), bytes.NewReader(upBody))
if err != nil {
return false, false, http.StatusInternalServerError, []byte("failed to build upstream request")
}
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Authorization", "Bearer "+upKey)
req.Header.Set("Accept", c.GetHeader("Accept"))
if ua := c.GetHeader("User-Agent"); ua != "" {
req.Header.Set("User-Agent", ua)
}
if plan.path == "/messages" {
// Anthropic 官方 API 只认 x-api-key(Bearer 是 OAuth token 的用法),
// 兼容网关两种都收;带上 anthropic-version 与客户端声明的 beta 头。
req.Header.Set("x-api-key", upKey)
req.Header.Set("anthropic-version", "2023-06-01")
if beta := c.GetHeader("anthropic-beta"); beta != "" {
req.Header.Set("anthropic-beta", beta)
}
}
for _, h := range []string{"OpenAI-Organization", "OpenAI-Project", "OpenAI-Beta"} {
if v := c.GetHeader(h); v != "" {
req.Header.Set(h, v)
}
}
start := time.Now()
resp, err := g.clientFor(limit).Do(req)
if err != nil {
// 客户端断开导致的取消:就地记账并终结本次请求(不计入渠道失败,也不换渠道)
if c.Request.Context().Err() != nil {
g.finishUsage(c, ch, start, store.UsageStatusCanceled, "client_disconnect")
return true, false, 0, nil
}
g.ch.ReportFailure(ch, channel.FailNet, 0) // 网络错误/超时
return false, true, http.StatusBadGateway, []byte("upstream request failed: " + err.Error())
}
defer resp.Body.Close()
// 非 2xx:按原因分类记账——429 不一定是限流(可能是余额/配额),402 也值得
// 换渠道(渠道 A 没余额不代表渠道 B 没有);其余透传错误体。
if resp.StatusCode < 200 || resp.StatusCode >= 300 {
errBody, _ := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
kind, retryable := classifyUpstreamError(resp.StatusCode, errBody)
if retryable {
g.ch.ReportFailure(ch, kind, retryAfter(resp.Header))
return false, true, resp.StatusCode, errBody
}
return false, false, resp.StatusCode, errBody
}
g.ch.ReportSuccess(ch)
// 协议形态校验:要流给了整包(或反过来)是劣质中转的常见毛病,按失败换渠道;
// 反复如此的渠道会被健康计数剔除(didNotStream 不会因重试而变好)。
ct := resp.Header.Get("Content-Type")
isSSE := strings.HasPrefix(ct, "text/event-stream")
if stream != isSSE {
_, _ = io.Copy(io.Discard, io.LimitReader(resp.Body, 4<<20)) // 排干以复用连接
g.ch.ReportFailure(ch, channel.FailServer, 0)
asked, got := "整包", "流式响应"
if stream {
asked, got = "流式", "整包响应"
}
return false, true, http.StatusBadGateway,
[]byte(ch.Name + " answered a " + asked + " request with " + got + " (didNotStream)")
}
if stream {
trySink := &usageSink{}
return g.streamHoldCopy(c, sh, ch, resp.Body, start, plan.lineConv, clientProto, trySink, sink, onRelease, tryCtx)
}
return g.copyAndCapture(c, ch, resp, start, plan.bodyConv, sink)
}
// copyAndCapture 非流式:先读完整上游响应再写客户端——响应头与正文都在"确定成功"后
// 才写出,读失败(网络错误/超时)发生在写出之前,可换渠道重试。
// 此前实现先写 200 头再读,超时只能给客户端留一个 200 空响应。
func (g *Gateway) copyAndCapture(c *gin.Context, ch *store.Channel, resp *http.Response, start time.Time, bodyConv func([]byte) ([]byte, error), sink *usageSink) (done bool, retry bool, status int, respBody []byte) {
data, err := io.ReadAll(resp.Body)
if err != nil {
switch {
case c.Request.Context().Err() != nil:
// 客户端断开:就地记账终结
g.finishUsage(c, ch, start, store.UsageStatusCanceled, "client_disconnect")
return true, false, 0, nil
case errors.Is(err, context.DeadlineExceeded):
g.ch.ReportFailure(ch, channel.FailNet, 0)
return false, true, http.StatusBadGateway, []byte(ch.Name + " upstream timeout")
default:
g.ch.ReportFailure(ch, channel.FailNet, 0)
return false, true, http.StatusBadGateway, []byte(ch.Name + " read error: " + err.Error())
}
}
if usageRaw := extractUsage(data); usageRaw != nil && sink != nil {
sink.push(usageRaw)
}
out := data
if bodyConv != nil {
if converted, cerr := bodyConv(data); cerr == nil {
out = converted
}
}
c.Header("Content-Type", resp.Header.Get("Content-Type"))
c.Status(http.StatusOK)
_, _ = c.Writer.Write(out)
if _, ok := c.Get("raw_request"); ok {
c.Set("raw_response", string(data)) // 上游原始响应(未转换)
}
g.finishUsage(c, ch, start, store.UsageStatusSuccess, "")
return true, false, 0, nil
}
// streamHoldCopy 流式转发:边读上游 SSE 边经 hold 写客户端(放行前缓冲)。
// 放行前的一切失败(上游错误事件、空流、断连、首 token 超时)都可换渠道重试,
// 健康计数就地上报;放行后的失败与旧语义一致,就地记账终结。
// trySink 收集本次尝试扫到的 usage,只有成功走到 EOF 才并入请求级 reqSink——
// 失败渠道的 message_start 用量不能计入最终账单。
func (g *Gateway) streamHoldCopy(c *gin.Context, sh *streamHold, ch *store.Channel, r io.Reader, start time.Time,
lineConv func([]byte) []byte, clientProto string, trySink, reqSink *usageSink, onRelease func(), tryCtx context.Context,
) (done bool, retry bool, status int, respBody []byte) {
// 原始响应捕获:仅管理员且开关开启(raw_request 已 set)时累积上游原始行
_, capture := c.Get("raw_request")
var rawResp strings.Builder
commitRaw := func() {
if capture {
c.Set("raw_response", rawResp.String())
}
}
scanner := newSSEScanner(r)
releaseSeen := false
fail := func(msg string, kind channel.FailKind) (bool, bool, int, []byte) {
g.ch.ReportFailure(ch, kind, 0)
return false, true, http.StatusBadGateway, []byte(ch.Name + ": " + msg)
}
for {
line, err := scanner.Next()
if line != nil {
if capture {
rawResp.Write(line)
}
// 上游错误事件(200+流式形式的错误):放行前换渠道消化
if !releaseSeen {
if msg, isErr := sseUpstreamError(line); isErr {
return fail("stream error: "+msg, channel.FailServer)
}
}
out := line
if lineConv != nil {
out = lineConv(line)
}
if out != nil {
if werr := sh.writeEvent(out); werr != nil {
// 客户端意外断开:按已生成部分收费(canceled)
commitRaw()
g.finishUsage(c, ch, start, store.UsageStatusCanceled, "client_disconnect")
return true, false, 0, nil
}
if trySink != nil {
trySink.outputText += sseContentText(out)
}
}
if !releaseSeen && sseEventHasContent(out, clientProto) {
releaseSeen = true
sh.release()
if onRelease != nil {
onRelease()
}
}
if usageRaw := scanUsage(line); usageRaw != nil && trySink != nil {
trySink.push(usageRaw)
}
}
if err != nil {
if releaseSeen {
// 已放行:客户端正在看内容,失败就地记账终结,与旧语义一致
commitRaw()
if err == io.EOF {
reqSink.merge(trySink)
g.finishUsage(c, ch, start, store.UsageStatusSuccess, "")
} else if c.Request.Context().Err() != nil {
g.finishUsage(c, ch, start, store.UsageStatusCanceled, "client_disconnect")
} else {
g.recordError(c, ch, nil, start, "stream_read_error")
}
return true, false, 0, nil
}
// 放行前失败:换渠道重试
if c.Request.Context().Err() != nil {
g.finishUsage(c, ch, start, store.UsageStatusCanceled, "client_disconnect")
return true, false, 0, nil
}
if tryCtx != nil && tryCtx.Err() != nil {
return fail(fmt.Sprintf("first token timeout (no content in %s)", g.firstTokenWait), channel.FailNet)
}
if err == io.EOF {
return fail("ended the stream before any content", channel.FailServer)
}
return fail("stream failed before any content: "+err.Error(), channel.FailNet)
}
}
}
// ---------------------------------------------------------------------------
// usage 提取
// usageShape 兼容 chat (prompt/completion)、responses (input/output)、messages (input/output) 命名。
type usageShape struct {
PromptTokens int64 `json:"prompt_tokens"`
CompletionTokens int64 `json:"completion_tokens"`
InputTokens int64 `json:"input_tokens"`
OutputTokens int64 `json:"output_tokens"`
TotalTokens int64 `json:"total_tokens"`
CacheReadInputTokens int64 `json:"cache_read_input_tokens"`
CacheCreationInputTokens int64 `json:"cache_creation_input_tokens"`
}
// extractUsage 从完整响应体提取 usage 子对象(chat / responses / messages)。
func extractUsage(data []byte) json.RawMessage {
var m map[string]json.RawMessage
if json.Unmarshal(data, &m) != nil {
return nil
}
if u := usageFromMap(m); u != nil {
return u
}
if respRaw, ok := m["response"]; ok {
var resp map[string]json.RawMessage
if json.Unmarshal(respRaw, &resp) == nil {
if u := usageFromMap(resp); u != nil {
return u
}
}
}
if choices, ok := m["choices"]; ok {
var cs []map[string]json.RawMessage
if json.Unmarshal(choices, &cs) == nil {
for _, ch := range cs {
if msgRaw, ok := ch["message"]; ok {
var msg map[string]json.RawMessage
if json.Unmarshal(msgRaw, &msg) == nil {
if u := usageFromMap(msg); u != nil {
return u
}
}
}
}
}
}
return nil
}
// scanUsage 从 SSE 一行中提取 usage(OpenAI 末块 / responses completed / messages message_delta 等)。
func scanUsage(line []byte) json.RawMessage {
if !bytes.Contains(line, []byte(`"usage"`)) {
return nil
}
s, ok := sseDataPayload(line)
if !ok {
return nil
}
var m map[string]json.RawMessage
if json.Unmarshal([]byte(s), &m) != nil {
return nil
}
if u := usageFromMap(m); u != nil {
return u
}
if respRaw, ok := m["response"]; ok {
var resp map[string]json.RawMessage
if json.Unmarshal(respRaw, &resp) == nil {
if u := usageFromMap(resp); u != nil {
return u
}
}
}
return nil
}
// usageFromMap 从 map 顶层、message 或 delta 子对象中取 usage。
// 覆盖三种形态:
// - OpenAI 流式末块顶层 usage
// - Anthropic 非流式 / message_start 的 message.usage
// - Anthropic 流式 message_delta 的 delta.usage(真实 token 计数所在)
func usageFromMap(m map[string]json.RawMessage) json.RawMessage {
if u, ok := m["usage"]; ok && string(u) != "null" {
return u
}
if msgRaw, ok := m["message"]; ok {
var msg map[string]json.RawMessage
if json.Unmarshal(msgRaw, &msg) == nil {
if u, ok := msg["usage"]; ok && string(u) != "null" {
return u
}
}
}
if deltaRaw, ok := m["delta"]; ok {
var delta map[string]json.RawMessage
if json.Unmarshal(deltaRaw, &delta) == nil {
if u, ok := delta["usage"]; ok && string(u) != "null" {
return u
}
}
}
return nil
}
// sseScanner 按 SSE 行边界读取(兼容 \n 与 \r\n),保留原始行内容。
type sseScanner struct {
r *bufio.Reader
}
func newSSEScanner(r io.Reader) *sseScanner { return &sseScanner{r: bufio.NewReaderSize(r, 32*1024)} }
func (s *sseScanner) Next() ([]byte, error) {
line, err := s.r.ReadBytes('\n')
if len(line) > 0 {
return line, nil
}
if err != nil {
return nil, err
}
return nil, io.EOF
}
// ---------------------------------------------------------------------------
// 记账
// usageSink 累积多次 usage:合并各事件字段(message_start 给 input,message_delta 给 output)。
// outputText 累积已转发内容文本,用于流式中断时按 tiktoken 估算输出 token。
type usageSink struct {
us usageShape
outputText string
}
func (u *usageSink) push(raw json.RawMessage) {
if len(raw) == 0 {
return
}
var t usageShape
if json.Unmarshal(raw, &t) != nil {
return
}
// messages 流式最终事件(message_delta 的 usage)带 cache_* 字段,是上游的最终计费口径,
// 其中 input_tokens 仅指"非缓存输入"(与 message_start 的"总输入"语义不同)。
// 整体替换而非字段合并,避免 delta 的非缓存 input 覆盖 start 的总 input 后语义错乱
// (实际消耗由 finishUsage 按 input + cache_read + cache_creation 汇总)。
if t.CacheReadInputTokens > 0 || t.CacheCreationInputTokens > 0 {
u.us = t
return
}
// 零值不覆盖:不同事件携带不同字段
if t.PromptTokens > 0 {
u.us.PromptTokens = t.PromptTokens
}
if t.CompletionTokens > 0 {
u.us.CompletionTokens = t.CompletionTokens
}
if t.InputTokens > 0 {
u.us.InputTokens = t.InputTokens
}
if t.OutputTokens > 0 {
u.us.OutputTokens = t.OutputTokens
}
if t.CacheReadInputTokens > 0 {
u.us.CacheReadInputTokens = t.CacheReadInputTokens
}
if t.CacheCreationInputTokens > 0 {
u.us.CacheCreationInputTokens = t.CacheCreationInputTokens
}
}
// Shape 返回合并后的用量。
func (u *usageSink) Shape() usageShape { return u.us }
// merge 并入一次成功尝试的用量:失败渠道的用量整体丢弃(换渠道重试时),
// 成功渠道的 usage 事件(含放行前缓冲期扫到的 message_start)在这里落账。
func (u *usageSink) merge(o *usageSink) {
if o == nil {
return
}
if o.us.PromptTokens > 0 {
u.us.PromptTokens = o.us.PromptTokens
}
if o.us.CompletionTokens > 0 {
u.us.CompletionTokens = o.us.CompletionTokens
}
if o.us.InputTokens > 0 {
u.us.InputTokens = o.us.InputTokens
}
if o.us.OutputTokens > 0 {
u.us.OutputTokens = o.us.OutputTokens
}
if o.us.CacheReadInputTokens > 0 {
u.us.CacheReadInputTokens = o.us.CacheReadInputTokens
}
if o.us.CacheCreationInputTokens > 0 {
u.us.CacheCreationInputTokens = o.us.CacheCreationInputTokens
}
u.outputText += o.outputText
}
// finishUsage 落账:计算成本并异步写入。
func (g *Gateway) finishUsage(c *gin.Context, ch *store.Channel, start time.Time, status, errCode string) {
uid, _ := c.Get(CtxUserID)
kid, _ := c.Get(CtxKeyID)
trace, _ := c.Get(CtxTrace)
var us usageShape
var sink *usageSink
if h, ok := c.Get("usage_raw"); ok {
if holder, ok := h.(*sinkHolder); ok && holder.sink != nil {
us = holder.sink.Shape()
sink = holder.sink
}
}
in := us.PromptTokens + us.InputTokens
out := us.CompletionTokens + us.OutputTokens
cacheRead := us.CacheReadInputTokens
cacheCreate := us.CacheCreationInputTokens
modelName, _ := c.Get("model_name")
mn, _ := modelName.(string)
// 上游未返回真实 usage 时估算(tiktoken):
// - 流式中断(canceled):上游最终 usage 可能未返回
// - 流式正常结束(success):部分上游(如火山方舟 Anthropic 流式)message_start.usage 恒为 0、
// message_delta 不带 usage,只能按已收发内容估算,否则记账为 0 消耗
// 非流式上游必返回 usage,此处 in/out 非 0 不受影响。
if status == store.UsageStatusCanceled || status == store.UsageStatusSuccess {
if in == 0 && cacheRead == 0 && cacheCreate == 0 {
if est, ok := c.Get("est_input_text"); ok {
if v, ok2 := est.(string); ok2 && v != "" {
in = int64(tokenizer.Count(v, mn))
}
}
}
if out == 0 && sink != nil && sink.outputText != "" {
out = int64(tokenizer.Count(sink.outputText, mn))
}
}
var model store.Model
var cost float64
var modelID uint64
_ = g.db.Where("name = ?", mn).First(&model).Error
if model.ID > 0 {
modelID = model.ID
// 计价口径:in=非缓存输入、cacheRead=缓存读、cacheCreate=缓存写(Anthropic 语义,
// messages 流式 message_delta 的 input_tokens 即非缓存部分)。
// 缓存写价未单独配置时按输入价 1.25×(Anthropic 5m 口径)。
cost = float64(in)/1e6*model.InputPrice +
float64(out)/1e6*model.OutputPrice +
float64(cacheRead)/1e6*model.CacheReadPrice +
float64(cacheCreate)/1e6*model.CacheWritePriceOr()
} else {
// 模型在记账时已被删除(请求进行中被下架):无法定价,按 0 记账留痕。
// 虚构单价扣用户的钱既不可审计也无法对账。
log.Printf("proxy: trace=%s model %q not found at billing time, cost recorded as 0", trace, mn)
}
// 落库的 input_tokens 存输入总量(含缓存读/写),与上游 message_start 口径一致,便于对账展示。
in += cacheRead + cacheCreate
proto, _ := c.Get("protocol")
p, _ := proto.(string)
if p == "" {
p = "chat"
}
traceStr, _ := trace.(string)
latency := int(time.Since(start).Milliseconds())
if status == store.UsageStatusSuccess && c.Writer.Status() >= 400 {
status = store.UsageStatusError
}
var errCodePtr *string
if errCode != "" {
errCodePtr = &errCode
}
var uidVal, kidVal uint64
if u, ok := uid.(uint64); ok {
uidVal = u
}
if k, ok := kid.(uint64); ok {
kidVal = k
}
var chID uint64
if ch != nil {
chID = ch.ID
}
var rawReq, rawResp string
if v, ok := c.Get("raw_request"); ok {
rawReq, _ = v.(string)
}
if v, ok := c.Get("raw_response"); ok {
rawResp, _ = v.(string)
}
// 密钥今日 token 用量累计(配额检查用)
if g.lim != nil && kidVal > 0 {
g.lim.AddTokens(kidVal, in+out)
}
g.rec.Record(&store.UsageLog{
RequestID: fmt.Sprintf("trace-%s", traceStr),
TraceID: traceStr,
UserID: uidVal,
KeyID: kidVal,
ChannelID: chID,
ModelID: modelID,
ModelName: mn,
Protocol: p,
InputTokens: in,
OutputTokens: out,
CacheReadTokens: cacheRead,
CacheCreationTokens: cacheCreate,
InputPrice: model.InputPrice,
OutputPrice: model.OutputPrice,
CacheReadPrice: model.CacheReadPrice,
Cost: cost,
LatencyMS: latency,
Status: status,
ErrorCode: errCodePtr,
RawRequest: rawReq,
RawResponse: rawResp,
CreatedAt: time.Now().UTC(),
})
// 请求级一行日志:usage_logs 落库是异步的且可能丢,排障时日志是唯一即时依据
log.Printf("proxy: trace=%s user=%d key=%d model=%q channel=%d proto=%s in=%d out=%d cache_r=%d cache_w=%d cost=%.6f status=%s http=%d latency=%dms err=%s",
traceStr, uidVal, kidVal, mn, chID, p, in, out, cacheRead, cacheCreate, cost, status,
c.Writer.Status(), latency, errCode)
}
// recordError 失败请求的记账(不产生扣费,status=error)。
func (g *Gateway) recordError(c *gin.Context, ch *store.Channel, resp *http.Response, start time.Time, code string) {
_ = resp
g.finishUsage(c, ch, start, store.UsageStatusError, code)
}
func now() time.Time { return time.Now() }