iop/apps/edge/internal/openai/anthropic_native.go

292 lines
8.2 KiB
Go

package openai
import (
"bytes"
"encoding/json"
"net/http"
"strings"
"time"
edgeservice "iop/apps/edge/internal/service"
iop "iop/proto/gen/iop"
)
var anthropicResponseHeaderAllowlist = map[string]struct{}{
"Cache-Control": {},
"Content-Length": {},
"Content-Type": {},
"Request-Id": {},
"Retry-After": {},
"X-Request-Id": {},
"X-Robots-Tag": {},
}
func (s *Server) writeAnthropicNativeTunnelResponse(w http.ResponseWriter, r *http.Request, handle edgeservice.ProviderTunnelResult, publicModelID string) {
frames := handle.Stream().Frames
if frames == nil {
writeAnthropicError(w, http.StatusBadGateway, "api_error", "provider tunnel is unavailable")
return
}
flusher, _ := w.(http.Flusher)
timer := time.NewTimer(handle.WaitTimeout())
defer timer.Stop()
wroteHeader := false
receivedResponseStart := false
responseStatus := http.StatusOK
responseStreaming := false
rewriteResponse := strings.TrimSpace(publicModelID) != ""
var responseBody []byte
var streamRewriter *anthropicNativeModelRewriter
for {
select {
case <-r.Context().Done():
s.cancelRunOnHTTPGiveUp(handle.Dispatch(), r.Context().Err())
return
case <-timer.C:
s.cancelRunOnHTTPGiveUp(handle.Dispatch(), errRunTimedOut)
if !wroteHeader {
writeAnthropicError(w, http.StatusBadGateway, "api_error", "provider response timed out")
}
return
case frame, ok := <-frames:
if !ok {
if !wroteHeader {
writeAnthropicError(w, http.StatusBadGateway, "api_error", "provider tunnel closed before a response")
}
return
}
switch frame.GetKind() {
case iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_RESPONSE_START:
if receivedResponseStart || wroteHeader {
continue
}
receivedResponseStart = true
copyAnthropicResponseHeaders(w.Header(), frame.GetHeaders())
status := int(frame.GetStatusCode())
if status == 0 {
status = http.StatusOK
}
responseStatus = status
if rewriteResponse && status >= http.StatusOK && status < http.StatusMultipleChoices {
w.Header().Del("Content-Length")
responseStreaming = strings.Contains(strings.ToLower(w.Header().Get("Content-Type")), "text/event-stream")
if responseStreaming {
streamRewriter = newAnthropicNativeModelRewriter(publicModelID)
w.WriteHeader(status)
wroteHeader = true
if flusher != nil {
flusher.Flush()
}
}
continue
}
w.WriteHeader(status)
wroteHeader = true
if flusher != nil {
flusher.Flush()
}
case iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_BODY:
if len(frame.GetBody()) == 0 {
continue
}
if rewriteResponse && receivedResponseStart && responseStatus >= http.StatusOK && responseStatus < http.StatusMultipleChoices {
if responseStreaming {
if err := writeAnthropicNativeBody(w, streamRewriter.Append(frame.GetBody()), flusher); err != nil {
s.sendCancelRun(handle.Dispatch())
return
}
} else {
responseBody = append(responseBody, frame.GetBody()...)
}
continue
}
if !wroteHeader {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
wroteHeader = true
}
if err := writeAnthropicNativeBody(w, frame.GetBody(), flusher); err != nil {
s.sendCancelRun(handle.Dispatch())
return
}
case iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_ERROR:
if !wroteHeader {
writeAnthropicError(w, http.StatusBadGateway, "api_error", "provider tunnel failed")
} else if strings.Contains(strings.ToLower(w.Header().Get("Content-Type")), "text/event-stream") {
_ = writeAnthropicSSEEvent(w, "error", anthropicErrorResponse{
Type: "error", Error: errorBody{Type: "api_error", Message: "provider tunnel failed"},
})
if flusher != nil {
flusher.Flush()
}
}
return
case iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_END:
if rewriteResponse && receivedResponseStart && responseStatus >= http.StatusOK && responseStatus < http.StatusMultipleChoices {
if responseStreaming {
if err := writeAnthropicNativeBody(w, streamRewriter.Flush(), flusher); err != nil {
s.sendCancelRun(handle.Dispatch())
}
return
}
if !wroteHeader {
w.WriteHeader(responseStatus)
wroteHeader = true
}
if err := writeAnthropicNativeBody(w, rewriteProviderJSONModel(responseBody, publicModelID), flusher); err != nil {
s.sendCancelRun(handle.Dispatch())
}
return
}
if !wroteHeader {
writeAnthropicError(w, http.StatusBadGateway, "api_error", "provider tunnel ended before a response")
}
return
case iop.ProviderTunnelFrameKind_PROVIDER_TUNNEL_FRAME_KIND_USAGE:
continue
}
}
}
}
func writeAnthropicNativeBody(w http.ResponseWriter, body []byte, flusher http.Flusher) error {
if len(body) == 0 {
return nil
}
if _, err := w.Write(body); err != nil {
return err
}
if flusher != nil {
flusher.Flush()
}
return nil
}
type anthropicNativeModelRewriter struct {
model string
pending []byte
messageStart bool
}
func newAnthropicNativeModelRewriter(model string) *anthropicNativeModelRewriter {
model = strings.TrimSpace(model)
if model == "" {
return nil
}
return &anthropicNativeModelRewriter{model: model}
}
func (r *anthropicNativeModelRewriter) Append(chunk []byte) []byte {
if r == nil || len(chunk) == 0 {
return chunk
}
r.pending = append(r.pending, chunk...)
var out bytes.Buffer
for {
index := bytes.IndexByte(r.pending, '\n')
if index < 0 {
break
}
line := r.pending[:index+1]
out.Write(r.rewriteLine(line))
r.pending = r.pending[index+1:]
}
return out.Bytes()
}
func (r *anthropicNativeModelRewriter) Flush() []byte {
if r == nil || len(r.pending) == 0 {
return nil
}
pending := r.pending
r.pending = nil
return r.rewriteLine(pending)
}
func (r *anthropicNativeModelRewriter) rewriteLine(line []byte) []byte {
body, ending := splitLineEnding(line)
prefix, payload, ok := bytes.Cut(body, []byte(":"))
if !ok {
return line
}
switch strings.TrimSpace(string(prefix)) {
case "event":
r.messageStart = strings.TrimSpace(string(payload)) == "message_start"
return line
case "data":
if !r.messageStart {
return line
}
r.messageStart = false
default:
return line
}
leading := len(payload) - len(bytes.TrimLeft(payload, " \t"))
trailing := len(payload) - len(bytes.TrimRight(payload, " \t"))
if leading+trailing >= len(payload) {
return line
}
rewritten := rewriteAnthropicMessageStartModel(payload[leading:len(payload)-trailing], r.model)
if bytes.Equal(rewritten, payload[leading:len(payload)-trailing]) {
return line
}
out := make([]byte, 0, len(body)+len(rewritten)-len(payload)+len(ending))
out = append(out, body[:len(prefix)+1+leading]...)
out = append(out, rewritten...)
out = append(out, payload[len(payload)-trailing:]...)
out = append(out, ending...)
return out
}
func rewriteAnthropicMessageStartModel(body []byte, model string) []byte {
modelJSON, err := json.Marshal(model)
if err != nil {
return body
}
fields, _, err := scanTopLevelJSONObject(body)
if err != nil {
return body
}
for _, field := range fields {
if field.name != "message" {
continue
}
message := body[field.valueFrom:field.valueTo]
messageFields, _, err := scanTopLevelJSONObject(message)
if err != nil {
return body
}
for _, messageField := range messageFields {
if messageField.name != "model" {
continue
}
plan, err := planTopLevelJSONPatches(message, []topLevelJSONPatch{{name: "model", value: modelJSON}})
if err != nil {
return body
}
return topLevelJSONPatchPlan{
body: body,
edits: []jsonByteEdit{{
from: field.valueFrom, to: field.valueTo, replacement: plan.apply(),
}},
outputSize: len(body) + plan.outputSize - len(message),
}.apply()
}
}
return body
}
func copyAnthropicResponseHeaders(dst http.Header, headers map[string]string) {
for key, value := range headers {
canonical := http.CanonicalHeaderKey(key)
_, exact := anthropicResponseHeaderAllowlist[canonical]
lower := strings.ToLower(key)
if !exact && !strings.HasPrefix(lower, "anthropic-ratelimit-") && !strings.HasPrefix(lower, "ratelimit-") {
continue
}
dst.Set(canonical, value)
}
}