chore: import upstream snapshot with attribution

components/document/interface.go

@@ -0,0 +1,55 @@
+/*
+ * 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 (
+	"context"
+
+	"github.com/cloudwego/eino/schema"
+)
+
+// Source identifies the external location of a document.
+// URI can be a local file path or a remote URL reachable by the loader.
+type Source struct {
+	URI string
+}
+
+//go:generate  mockgen -destination ../../internal/mock/components/document/document_mock.go --package document -source interface.go
+
+// Loader reads raw content from an external source and returns it as a slice
+// of [schema.Document] values.
+//
+// The Source.URI may be a local file path or a remote URL. The loader is
+// responsible for fetching the raw bytes; actual format parsing is typically
+// delegated to a [parser.Parser] configured on the loader via
+// [WithParserOptions].
+//
+// Document metadata ([schema.Document].MetaData) should be populated with at
+// least the source URI so that downstream nodes can trace document provenance.
+type Loader interface {
+	Load(ctx context.Context, src Source, opts ...LoaderOption) ([]*schema.Document, error)
+}
+
+// Transformer converts a slice of [schema.Document] values into another slice,
+// applying operations such as splitting, filtering, merging, or re-ranking.
+//
+// Implementations should preserve existing MetaData keys and merge rather than
+// replace when adding their own metadata. Downstream nodes (e.g. Indexer,
+// Retriever) may depend on metadata set by earlier pipeline stages.
+type Transformer interface {
+	Transform(ctx context.Context, src []*schema.Document, opts ...TransformerOption) ([]*schema.Document, error)
+}