chore: import upstream snapshot with attribution

components/document/callback_extra_loader.go

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2024 CloudWeGo 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 document
+
+import (
+	"github.com/cloudwego/eino/callbacks"
+	"github.com/cloudwego/eino/schema"
+)
+
+// LoaderCallbackInput is the input for the loader callback.
+type LoaderCallbackInput struct {
+	// Source is the source of the documents.
+	Source Source
+
+	// Extra is the extra information for the callback.
+	Extra map[string]any
+}
+
+// LoaderCallbackOutput is the output for the loader callback.
+type LoaderCallbackOutput struct {
+	// Source is the source of the documents.
+	Source Source
+
+	// Docs is the documents to be loaded.
+	Docs []*schema.Document
+
+	// Extra is the extra information for the callback.
+	Extra map[string]any
+}
+
+// ConvLoaderCallbackInput converts the callback input to the loader callback input.
+func ConvLoaderCallbackInput(src callbacks.CallbackInput) *LoaderCallbackInput {
+	switch t := src.(type) {
+	case *LoaderCallbackInput:
+		return t
+	case Source:
+		return &LoaderCallbackInput{
+			Source: t,
+		}
+	default:
+		return nil
+	}
+}
+
+// ConvLoaderCallbackOutput converts the callback output to the loader callback output.
+func ConvLoaderCallbackOutput(src callbacks.CallbackOutput) *LoaderCallbackOutput {
+	switch t := src.(type) {
+	case *LoaderCallbackOutput:
+		return t
+	case []*schema.Document:
+		return &LoaderCallbackOutput{
+			Docs: t,
+		}
+	default:
+		return nil
+	}
+}