1// Package rotree provides a read-only wrapper for bptree.BPTree with safe value transformation.2//3// It is useful when you want to expose a read-only view of a tree while ensuring that4// the sensitive data cannot be modified.5//6// Example:7//8// // Define a user structure with sensitive data9// type User struct {10// Name string11// Balance int12// Internal string // sensitive field13// }14//15// // Create and populate the original tree16// privateTree := bptree.NewBPTree32()17// privateTree.Set("alice", &User{18// Name: "Alice",19// Balance: 100,20// Internal: "sensitive",21// })22//23// // Create a safe transformation function that copies the struct24// // while excluding sensitive data25// makeEntrySafeFn := func(v any) any {26// u := v.(*User)27// return &User{28// Name: u.Name,29// Balance: u.Balance,30// Internal: "", // omit sensitive data31// }32// }33//34// // Create a read-only view of the tree35// PublicTree := rotree.Wrap(tree, makeEntrySafeFn)36//37// // Safely access the data38// value := roTree.Get("alice")39// user := value.(*User)40// // user.Name == "Alice"41// // user.Balance == 10042// // user.Internal == "" (sensitive data is filtered)43package rotree4445import (46 "gno.land/p/nt/bptree/v0"47)4849// Wrap creates a new ReadOnlyTree from an existing bptree.BPTree and a safety transformation function.50// If makeEntrySafeFn is nil, values will be returned as-is without transformation.51func Wrap(tree *bptree.BPTree, makeEntrySafeFn func(any) any) *ReadOnlyTree {52 return &ReadOnlyTree{53 tree: tree,54 makeEntrySafeFn: makeEntrySafeFn,55 }56}5758// ReadOnlyTree wraps a bptree.BPTree and provides read-only access.59type ReadOnlyTree struct {60 tree *bptree.BPTree61 makeEntrySafeFn func(any) any62}6364// IReadOnlyTree defines the read-only operations available on a tree.65type IReadOnlyTree interface {66 Size() int67 Has(key string) bool68 Get(key string) any69 GetByIndex(index int) (string, any)70 Iterate(start, end string, cb bptree.IterCbFn) bool71 ReverseIterate(start, end string, cb bptree.IterCbFn) bool72 IterateByOffset(offset int, count int, cb bptree.IterCbFn) bool73 ReverseIterateByOffset(offset int, count int, cb bptree.IterCbFn) bool74}7576// Verify that ReadOnlyTree implements both ITree and IReadOnlyTree77var (78 _ bptree.ITree = (*ReadOnlyTree)(nil)79 _ IReadOnlyTree = (*ReadOnlyTree)(nil)80)8182// getSafeValue applies the makeEntrySafeFn if it exists, otherwise returns the original value83func (roTree *ReadOnlyTree) getSafeValue(value any) any {84 if roTree.makeEntrySafeFn == nil {85 return value86 }87 return roTree.makeEntrySafeFn(value)88}8990// Size returns the number of key-value pairs in the tree.91func (roTree *ReadOnlyTree) Size() int {92 return roTree.tree.Size()93}9495// Has checks whether a key exists in the tree.96func (roTree *ReadOnlyTree) Has(key string) bool {97 return roTree.tree.Has(key)98}99100// Get retrieves the value associated with the given key, converted to a safe format.101// It returns the value if the key exists, or nil if it doesn't.102func (roTree *ReadOnlyTree) Get(key string) any {103 value := roTree.tree.Get(key)104 if value == nil {105 return nil106 }107 return roTree.getSafeValue(value)108}109110// GetByIndex retrieves the key-value pair at the specified index in the tree, with the value converted to a safe format.111func (roTree *ReadOnlyTree) GetByIndex(index int) (string, any) {112 key, value := roTree.tree.GetByIndex(index)113 return key, roTree.getSafeValue(value)114}115116// Iterate performs an in-order traversal of the tree within the specified key range.117func (roTree *ReadOnlyTree) Iterate(start, end string, cb bptree.IterCbFn) bool {118 return roTree.tree.Iterate(start, end, func(key string, value any) bool {119 return cb(key, roTree.getSafeValue(value))120 })121}122123// ReverseIterate performs a reverse in-order traversal of the tree within the specified key range.124func (roTree *ReadOnlyTree) ReverseIterate(start, end string, cb bptree.IterCbFn) bool {125 return roTree.tree.ReverseIterate(start, end, func(key string, value any) bool {126 return cb(key, roTree.getSafeValue(value))127 })128}129130// IterateByOffset performs an in-order traversal of the tree starting from the specified offset.131func (roTree *ReadOnlyTree) IterateByOffset(offset int, count int, cb bptree.IterCbFn) bool {132 return roTree.tree.IterateByOffset(offset, count, func(key string, value any) bool {133 return cb(key, roTree.getSafeValue(value))134 })135}136137// ReverseIterateByOffset performs a reverse in-order traversal of the tree starting from the specified offset.138func (roTree *ReadOnlyTree) ReverseIterateByOffset(offset int, count int, cb bptree.IterCbFn) bool {139 return roTree.tree.ReverseIterateByOffset(offset, count, func(key string, value any) bool {140 return cb(key, roTree.getSafeValue(value))141 })142}143144// Set is not supported on ReadOnlyTree and will panic.145func (roTree *ReadOnlyTree) Set(key string, value any) bool {146 panic("Set operation not supported on ReadOnlyTree")147}148149// Remove is not supported on ReadOnlyTree and will panic.150func (roTree *ReadOnlyTree) Remove(key string) (value any, removed bool) {151 panic("Remove operation not supported on ReadOnlyTree")152}153Signatures reconstructed verbatim from vm/qfuncs — interface params keep their inline definitions.