Storage: add basic storage service (#46604)

pkg/services/store/tree.go

@@ -0,0 +1,106 @@
+package store
+
+import (
+	"context"
+
+	"github.com/grafana/grafana-plugin-sdk-go/data"
+	"github.com/grafana/grafana/pkg/infra/filestorage"
+)
+
+type nestedTree struct {
+	roots  []storageRuntime
+	lookup map[string]filestorage.FileStorage
+}
+
+var (
+	_ storageTree = (*nestedTree)(nil)
+)
+
+func (t *nestedTree) init() {
+	t.lookup = make(map[string]filestorage.FileStorage, len(t.roots))
+	for _, root := range t.roots {
+		t.lookup[root.Meta().Config.Prefix] = root.Store()
+	}
+}
+
+func (t *nestedTree) getRoot(path string) (filestorage.FileStorage, string) {
+	if path == "" {
+		return nil, ""
+	}
+
+	rootKey, path := splitFirstSegment(path)
+	root, ok := t.lookup[rootKey]
+	if !ok || root == nil {
+		return nil, path // not found or not ready
+	}
+	return root, filestorage.Delimiter + path
+}
+
+func (t *nestedTree) GetFile(ctx context.Context, path string) (*filestorage.File, error) {
+	if path == "" {
+		return nil, nil // not found
+	}
+
+	root, path := t.getRoot(path)
+	if root == nil {
+		return nil, nil // not found (or not ready)
+	}
+	return root.Get(ctx, path)
+}
+
+func (t *nestedTree) ListFolder(ctx context.Context, path string) (*data.Frame, error) {
+	if path == "" || path == "/" {
+		count := len(t.roots)
+		title := data.NewFieldFromFieldType(data.FieldTypeString, count)
+		names := data.NewFieldFromFieldType(data.FieldTypeString, count)
+		mtype := data.NewFieldFromFieldType(data.FieldTypeString, count)
+		title.Name = "title"
+		names.Name = "name"
+		mtype.Name = "mediaType"
+		for i, f := range t.roots {
+			names.Set(i, f.Meta().Config.Prefix)
+			title.Set(i, f.Meta().Config.Name)
+			mtype.Set(i, "directory")
+		}
+		frame := data.NewFrame("", names, title, mtype)
+		frame.SetMeta(&data.FrameMeta{
+			Type: data.FrameTypeDirectoryListing,
+		})
+		return frame, nil
+	}
+
+	root, path := t.getRoot(path)
+	if root == nil {
+		return nil, nil // not found (or not ready)
+	}
+
+	listResponse, err := root.List(ctx, path, nil, &filestorage.ListOptions{Recursive: false, WithFolders: true, WithFiles: true})
+
+	if err != nil {
+		return nil, err
+	}
+
+	count := len(listResponse.Files)
+	names := data.NewFieldFromFieldType(data.FieldTypeString, count)
+	mtype := data.NewFieldFromFieldType(data.FieldTypeString, count)
+	fsize := data.NewFieldFromFieldType(data.FieldTypeInt64, count)
+	names.Name = "name"
+	mtype.Name = "mediaType"
+	fsize.Name = "size"
+	fsize.Config = &data.FieldConfig{
+		Unit: "bytes",
+	}
+	for i, f := range listResponse.Files {
+		names.Set(i, f.Name)
+		mtype.Set(i, f.MimeType)
+		fsize.Set(i, f.Size)
+	}
+	frame := data.NewFrame("", names, mtype, fsize)
+	frame.SetMeta(&data.FrameMeta{
+		Type: data.FrameTypeDirectoryListing,
+		Custom: map[string]interface{}{
+			"HasMore": listResponse.HasMore,
+		},
+	})
+	return frame, nil
+}