Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/service/openai_sse_json_documents.go

@@ -0,0 +1,115 @@
+package service
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"io"
+	"strings"
+)
+
+const (
+	maxOpenAIConcatenatedJSONDocuments = 16
+	maxOpenAIConcatenatedJSONBytes     = 16 * 1024 * 1024
+)
+
+// splitOpenAIConcatenatedJSONDocuments recognizes the narrow corruption shape
+// produced when multiple complete Responses events arrive in one transport
+// message. Other malformed payloads are left untouched for normal error paths.
+func splitOpenAIConcatenatedJSONDocuments(payload []byte) ([][]byte, bool) {
+	payload = bytes.TrimSpace(payload)
+	if len(payload) == 0 || len(payload) > maxOpenAIConcatenatedJSONBytes || json.Valid(payload) {
+		return nil, false
+	}
+
+	decoder := json.NewDecoder(bytes.NewReader(payload))
+	documents := make([][]byte, 0, 2)
+	for {
+		var raw json.RawMessage
+		err := decoder.Decode(&raw)
+		if err != nil {
+			if err == io.EOF && len(documents) > 1 {
+				return documents, true
+			}
+			return nil, false
+		}
+		raw = bytes.TrimSpace(raw)
+		var envelope struct {
+			Type string `json:"type"`
+		}
+		if err := json.Unmarshal(raw, &envelope); err != nil {
+			return nil, false
+		}
+		eventType := strings.TrimSpace(envelope.Type)
+		if eventType == "" || strings.ContainsAny(eventType, "\r\n") {
+			return nil, false
+		}
+		if len(documents) == maxOpenAIConcatenatedJSONDocuments {
+			return nil, false
+		}
+		documents = append(documents, raw)
+	}
+}
+
+type openAISSEJSONDocumentScanner struct {
+	scanner *bufio.Scanner
+	pending []string
+	current string
+}
+
+func newOpenAISSEJSONDocumentScanner(scanner *bufio.Scanner) *openAISSEJSONDocumentScanner {
+	return &openAISSEJSONDocumentScanner{scanner: scanner}
+}
+
+func (s *openAISSEJSONDocumentScanner) Scan() bool {
+	if len(s.pending) > 0 {
+		s.current = s.pending[0]
+		s.pending = s.pending[1:]
+		return true
+	}
+	if s.scanner == nil || !s.scanner.Scan() {
+		return false
+	}
+
+	line := s.scanner.Text()
+	data, ok := extractOpenAISSEDataLine(line)
+	if !ok {
+		s.current = line
+		return true
+	}
+	if len(data) > maxOpenAIConcatenatedJSONBytes {
+		s.current = line
+		return true
+	}
+	documents, repaired := splitOpenAIConcatenatedJSONDocuments([]byte(data))
+	if !repaired {
+		s.current = line
+		return true
+	}
+
+	expanded := make([]string, 0, len(documents)*3)
+	for i, document := range documents {
+		if i > 0 {
+			var envelope struct {
+				Type string `json:"type"`
+			}
+			_ = json.Unmarshal(document, &envelope)
+			expanded = append(expanded, "event: "+strings.TrimSpace(envelope.Type))
+		}
+		expanded = append(expanded, "data: "+string(document), "")
+	}
+	s.current = expanded[0]
+	s.pending = expanded[1:]
+	return true
+}
+
+func (s *openAISSEJSONDocumentScanner) Text() string {
+	return s.current
+}
+
+func (s *openAISSEJSONDocumentScanner) Err() error {
+	if s.scanner == nil {
+		return nil
+	}
+	return s.scanner.Err()
+}