package mpt import ( "encoding/hex" "errors" "fmt" "github.com/nspcc-dev/neo-go/pkg/core/storage" "github.com/nspcc-dev/neo-go/pkg/io" "github.com/nspcc-dev/neo-go/pkg/util" ) // MaxValueLength is the max length of a leaf node value. const MaxValueLength = 3 + storage.MaxStorageValueLen + 1 // LeafNode represents an MPT's leaf node. type LeafNode struct { BaseNode value []byte } var _ Node = (*LeafNode)(nil) // NewLeafNode returns a hash node with the specified value. func NewLeafNode(value []byte) *LeafNode { return &LeafNode{value: value} } // Type implements Node interface. func (n LeafNode) Type() NodeType { return LeafT } // Hash implements BaseNode interface. func (n *LeafNode) Hash() util.Uint256 { return n.getHash(n) } // Bytes implements BaseNode interface. func (n *LeafNode) Bytes() []byte { return n.getBytes(n) } // DecodeBinary implements io.Serializable. func (n *LeafNode) DecodeBinary(r *io.BinReader) { sz := r.ReadVarUint() if sz > MaxValueLength { r.Err = fmt.Errorf("leaf node value is too big: %d", sz) return } n.value = make([]byte, sz) r.ReadBytes(n.value) n.invalidateCache() } // EncodeBinary implements io.Serializable. func (n LeafNode) EncodeBinary(w *io.BinWriter) { w.WriteVarBytes(n.value) } // Size implements Node interface. func (n *LeafNode) Size() int { return io.GetVarSize(len(n.value)) + len(n.value) } // MarshalJSON implements the json.Marshaler. func (n *LeafNode) MarshalJSON() ([]byte, error) { return []byte(`{"value":"` + hex.EncodeToString(n.value) + `"}`), nil } // UnmarshalJSON implements the json.Unmarshaler. func (n *LeafNode) UnmarshalJSON(data []byte) error { var obj NodeObject if err := obj.UnmarshalJSON(data); err != nil { return err } else if u, ok := obj.Node.(*LeafNode); ok { *n = *u return nil } return errors.New("expected leaf node") } // Clone implements Node interface. func (n *LeafNode) Clone() Node { res := *n return &res }