github.com/chain5j/chain5j-pkg@v1.0.7/collection/trees/tree/tree.go

// Package tree
//
// @author: xwc1125
package tree

import (
	"github.com/chain5j/chain5j-pkg/database/kvstore"
	"github.com/chain5j/chain5j-pkg/types"
)

type Tree interface {
	// TryGet returns the value for key stored in the trie. The value bytes must
	// not be modified by the caller. If a node was not found in the database, a
	// trie.MissingNodeError is returned.
	TryGet(key []byte) ([]byte, error)

	// TryUpdate associates key with value in the trie. If value has length zero, any
	// existing value is deleted from the trie. The value bytes must not be modified
	// by the caller while they are stored in the trie. If a node was not found in the
	// database, a trie.MissingNodeError is returned.
	TryUpdate(key, value []byte) error

	// TryDelete removes any existing value for key from the trie. If a node was not
	// found in the database, a trie.MissingNodeError is returned.
	TryDelete(key []byte) error

	// Hash returns the root hash of the trie. It does not write to the database and
	// can be used even if the trie doesn't have one.
	Hash() types.Hash

	// Commit writes all nodes to the trie's memory database, tracking the internal
	// and external (for account tries) references.
	Commit(onleaf LeafCallback) (types.Hash, error)

	// NodeIterator returns an iterator that returns nodes of the trie. Iteration
	// starts at the key after the given start key.
	NodeIterator(startKey []byte) NodeIterator

	// Prove constructs a Merkle proof for key. The result contains all encoded nodes
	// on the path to the value at key. The value itself is also included in the last
	// node and can be retrieved by verifying the proof.
	//
	// If the trie does not contain a value for key, the returned proof contains all
	// nodes of the longest existing prefix of the key (at least the root), ending
	// with the node that proves the absence of the key.
	Prove(key []byte, fromLevel uint, proofDb kvstore.KeyValueWriter) error
}