EntityAPI: Save nested summary info in the SQL database (#61732)

pkg/services/store/entity/sqlstash/folder_support.go

@@ -11,15 +11,23 @@ import (
 
 type folderInfo struct {
 	UID  string `json:"uid"`
-	Name string `json:"name"`
-	Slug string `json:"slug"`
+	Name string `json:"name"` // original display name
+	Slug string `json:"slug"` // full slug
+
+	// original slug
+	originalSlug string
+
+	depth int32
+	left  int32
+	right int32
 
 	// Build the tree
-	ParentUID string `json:"-"`
+	parentUID string
 
-	// Added after query
-	children []*folderInfo
+	// Calculated after query
 	parent   *folderInfo
+	children []*folderInfo
+	stack    []*folderInfo
 }
 
 // This will replace all entries in `entity_folder`
@@ -32,7 +40,6 @@ func updateFolderTree(ctx context.Context, tx *session.SessionTx, tenant int64)
 	}
 
 	all := []*folderInfo{}
-	lookup := make(map[string]*folderInfo)
 	rows, err := tx.Query(ctx, "SELECT uid,folder,name,slug FROM entity WHERE kind=? AND tenant_id=? ORDER BY slug asc;",
 		models.StandardKindFolder, tenant)
 	if err != nil {
@@ -42,11 +49,10 @@ func updateFolderTree(ctx context.Context, tx *session.SessionTx, tenant int64)
 		folder := folderInfo{
 			children: []*folderInfo{},
 		}
-		err = rows.Scan(&folder.UID, &folder.ParentUID, &folder.Name, &folder.Slug)
+		err = rows.Scan(&folder.UID, &folder.parentUID, &folder.Name, &folder.originalSlug)
 		if err != nil {
 			return err
 		}
-		lookup[folder.UID] = &folder
 		all = append(all, &folder)
 	}
 	err = rows.Close()
@@ -54,16 +60,43 @@ func updateFolderTree(ctx context.Context, tx *session.SessionTx, tenant int64)
 		return err
 	}
 
+	root, lost, err := buildFolderTree(all)
+	if err != nil {
+		return err
+	}
+
+	err = insertFolderInfo(ctx, tx, tenant, root, false)
+	if err != nil {
+		return err
+	}
+
+	for _, folder := range lost {
+		err = insertFolderInfo(ctx, tx, tenant, folder, true)
+		if err != nil {
+			return err
+		}
+	}
+	return err
+}
+
+func buildFolderTree(all []*folderInfo) (*folderInfo, []*folderInfo, error) {
+	lost := []*folderInfo{}
+	lookup := make(map[string]*folderInfo)
+	for _, folder := range all {
+		lookup[folder.UID] = folder
+	}
+
 	root := &folderInfo{
 		Name:     "Root",
+		UID:      "",
 		children: []*folderInfo{},
+		left:     1,
 	}
 	lookup[""] = root
-	lost := []*folderInfo{}
 
 	// already sorted by slug
 	for _, folder := range all {
-		parent, ok := lookup[folder.ParentUID]
+		parent, ok := lookup[folder.parentUID]
 		if ok {
 			folder.parent = parent
 			parent.children = append(parent.children, folder)
@@ -72,40 +105,49 @@ func updateFolderTree(ctx context.Context, tx *session.SessionTx, tenant int64)
 		}
 	}
 
-	for _, folder := range root.children {
-		err = addFolderInfo(ctx, tx, tenant, []*folderInfo{folder}, false)
-		if err != nil {
-			return err
-		}
-	}
-	for _, folder := range lost {
-		err = addFolderInfo(ctx, tx, tenant, []*folderInfo{folder}, true)
-		if err != nil {
-			return err
-		}
-	}
-	return err
+	_, err := setMPTTOrder(root, []*folderInfo{}, int32(1))
+	return root, lost, err
 }
 
-func addFolderInfo(ctx context.Context, tx *session.SessionTx, tenant int64, tree []*folderInfo, isDetached bool) error {
-	folder := tree[len(tree)-1] // last item in the tree
+// https://imrannazar.com/Modified-Preorder-Tree-Traversal
+func setMPTTOrder(folder *folderInfo, stack []*folderInfo, idx int32) (int32, error) {
+	var err error
+	folder.depth = int32(len(stack))
+	folder.left = idx
+	folder.stack = stack
 
-	js, _ := json.Marshal(tree)
-	slugPath := "/"
-	for _, f := range tree {
-		slugPath += f.Slug + "/"
+	if folder.depth > 0 {
+		folder.Slug = "/"
+		for _, f := range stack {
+			folder.Slug += f.originalSlug + "/"
+		}
 	}
+
+	for _, child := range folder.children {
+		idx, err = setMPTTOrder(child, append(stack, child), idx+1)
+		if err != nil {
+			return idx, err
+		}
+	}
+	folder.right = idx + 1
+	return folder.right, nil
+}
+
+func insertFolderInfo(ctx context.Context, tx *session.SessionTx, tenant int64, folder *folderInfo, isDetached bool) error {
+	js, _ := json.Marshal(folder.stack)
 	grn := entity.GRN{TenantId: tenant, Kind: models.StandardKindFolder, UID: folder.UID}
 	_, err := tx.Exec(ctx,
 		`INSERT INTO entity_folder `+
-			"(grn, tenant_id, uid, slug_path, tree, depth, detached) "+
-			`VALUES (?, ?, ?, ?, ?, ?, ?)`,
+			"(grn, tenant_id, uid, slug_path, tree, depth, left, right, detached) "+
+			`VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
 		grn.ToGRNString(),
 		tenant,
 		folder.UID,
-		slugPath,
+		folder.Slug,
 		string(js),
-		len(tree),
+		folder.depth,
+		folder.left,
+		folder.right,
 		isDetached,
 	)
 	if err != nil {
@@ -113,7 +155,7 @@ func addFolderInfo(ctx context.Context, tx *session.SessionTx, tenant int64, tre
 	}
 
 	for _, sub := range folder.children {
-		err := addFolderInfo(ctx, tx, tenant, append(tree, sub), isDetached)
+		err := insertFolderInfo(ctx, tx, tenant, sub, isDetached)
 		if err != nil {
 			return err
 		}