feat: manually mirror opencoze's code from bytedance

Change-Id: I09a73aadda978ad9511264a756b2ce51f5761adf

backend/infra/contract/document/rerank/rerank.go

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2025 coze-dev Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package rerank
+
+import (
+	"context"
+
+	"github.com/cloudwego/eino/schema"
+)
+
+type Reranker interface {
+	Rerank(ctx context.Context, req *Request) (*Response, error)
+}
+
+type Request struct {
+	Query string
+	Data  [][]*Data
+	TopN  *int64
+}
+
+type Response struct {
+	SortedData []*Data // 高分在前
+	TokenUsage *int64
+}
+
+type Data struct {
+	Document *schema.Document
+	Score    float64
+}