126 lines
2.9 KiB
Go
126 lines
2.9 KiB
Go
package eino
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import (
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"context"
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"errors"
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"fmt"
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"io"
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"rag/consts/model"
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"github.com/cloudwego/eino/components/prompt"
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"github.com/cloudwego/eino/schema"
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)
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const (
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MaxHistoryTurns = 5 // 最大历史轮数
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)
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var (
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ragPromptTemplate prompt.ChatTemplate // EINO 官方模板
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)
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func init() {
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// 初始化 EINO 提示词模板
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initRAGPromptTemplate()
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return
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}
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// 初始化 EINO 官方提示词模板（最关键！）
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func initRAGPromptTemplate() {
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ragPromptTemplate = prompt.FromMessages(
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schema.FString,
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// 系统提示（带参考知识）
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&schema.Message{
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Role: schema.System,
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Content: `你是专业客服，语气友好简洁。
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请依据参考知识回答，不知道就说：抱歉，我暂时无法回答这个问题。
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参考知识：
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{knowledge}`,
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},
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// 用户问题
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&schema.Message{
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Role: schema.User,
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Content: "{question}",
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},
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)
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}
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// NewChatModel 只处理逻辑，不复用创建模型
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func NewChatModel(ctx context.Context, question string, docs []*schema.Document, history []*schema.Message, chatModel model.ModelConfigType) (replyMsg *schema.Message, err error) {
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// 1. 构建参考知识
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knowledge := buildKnowledgeAndSources(docs)
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// 2. 历史精简
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history = limitHistory(history)
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// 3. ✅ EINO 官方模板格式化（超级干净）
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msgs, err := ragPromptTemplate.Format(ctx, map[string]any{
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"knowledge": knowledge,
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"question": question,
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})
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if err != nil {
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return nil, err
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}
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// 4. 历史插入到模板消息中间（标准EINO用法）
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if len(history) > 0 {
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msgs = append(msgs[:1], append(history, msgs[1:]...)...)
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}
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// 5. 🔥 直接使用全局单例，不重复创建
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replyMsg, err = streamGenerateAnswer(ctx, msgs, chatModel)
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return
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}
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func limitHistory(history []*schema.Message) []*schema.Message {
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valid := make([]*schema.Message, 0, len(history))
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for _, m := range history {
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if m.Role == schema.User || m.Role == schema.Assistant {
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valid = append(valid, m)
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}
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}
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keep := 2 * MaxHistoryTurns
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if len(valid) > keep {
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valid = valid[len(valid)-keep:]
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}
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return valid
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}
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// buildKnowledgeAndSources 拼接参考知识
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func buildKnowledgeAndSources(docs []*schema.Document) string {
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var knowledge string
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for i, doc := range docs {
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knowledge += fmt.Sprintf("[参考%d] %s\n", i+1, doc.Content)
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}
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return knowledge
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}
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// streamGenerateAnswer 流式生成
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func streamGenerateAnswer(ctx context.Context, msgs []*schema.Message, chatModel model.ModelConfigType) (reply *schema.Message, err error) {
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cm, err := GetTenantChatModelByType(ctx, chatModel)
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if err != nil {
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return nil, err
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}
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sr, err := cm.Stream(ctx, msgs)
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if err != nil {
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return nil, fmt.Errorf("stream failed: %w", err)
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}
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var chunks []*schema.Message
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for {
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chunk, err := sr.Recv()
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if errors.Is(err, io.EOF) {
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break
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}
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if err != nil {
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return nil, fmt.Errorf("stream recv failed: %w", err)
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}
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chunks = append(chunks, chunk)
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}
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return schema.ConcatMessages(chunks)
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}
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