first commit

internal/llm/sse.go

@@ -0,0 +1,61 @@
+package llm
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+)
+
+// sseEvent 是一条 Server-Sent Events 事件。
+type sseEvent struct {
+	Name string
+	Data []byte
+}
+
+// readSSE 逐条解析 SSE 流。兼容 OpenAI 的 "data: {...}" 格式，
+// 也兼容心跳注释行（以 ":" 开头）与自定义 event 名。
+func readSSE(r io.Reader, handle func(sseEvent) error) error {
+	br := bufio.NewReaderSize(r, 64*1024)
+	var data bytes.Buffer
+	var name string
+
+	flush := func() error {
+		if data.Len() == 0 {
+			return nil
+		}
+		ev := sseEvent{Name: name, Data: bytes.TrimSpace(data.Bytes())}
+		data.Reset()
+		name = ""
+		return handle(ev)
+	}
+
+	for {
+		line, err := br.ReadBytes('\n')
+		if len(line) > 0 {
+			line = bytes.TrimRight(line, "\r\n")
+			switch {
+			case len(line) == 0:
+				if ferr := flush(); ferr != nil {
+					return ferr
+				}
+			case bytes.HasPrefix(line, []byte(":")):
+				// 注释/心跳，忽略
+			case bytes.HasPrefix(line, []byte("data:")):
+				v := bytes.TrimPrefix(bytes.TrimPrefix(line, []byte("data:")), []byte(" "))
+				if data.Len() > 0 {
+					data.WriteByte('\n')
+				}
+				data.Write(v)
+			case bytes.HasPrefix(line, []byte("event:")):
+				name = string(bytes.TrimSpace(bytes.TrimPrefix(line, []byte("event:"))))
+			}
+		}
+		if err != nil {
+			_ = flush()
+			if err == io.EOF {
+				return nil
+			}
+			return err
+		}
+	}
+}