trie

type Iterator interface {
	Next() ([]byte, []byte, error)
}

type KVStore interface {
	// Start starts the KVStore
	Start(context.Context) error
	// Stop stops the KVStore
	Stop(context.Context) error
	// Put puts key, value pair into KVStore
	Put([]byte, []byte) error
	// Delete deletes record from KVStore by key
	Delete([]byte) error
	// Get gets the value from KVStore by key
	Get([]byte) ([]byte, error)
}

type Trie interface {
	// Start starts the trie and the corresponding dependencies
	Start(context.Context) error
	// Stop stops the trie
	Stop(context.Context) error
	// Upsert inserts a new entry
	Upsert([]byte, []byte) error
	// Get retrieves an existing entry
	Get([]byte) ([]byte, error)
	// Delete deletes an entry
	Delete([]byte) error
	// RootHash returns trie's root hash
	RootHash() ([]byte, error)
	// SetRootHash sets a new root to trie
	SetRootHash([]byte) error
	// IsEmpty returns true is this is an empty trie
	IsEmpty() bool
	// Clone clones a trie with a new kvstore
	Clone(KVStore) (Trie, error)
}

type TwoLayerTrie interface {
	// Start starts the layer one trie
	Start(context.Context) error
	// Stop stops the layer one trie
	Stop(context.Context) error
	// RootHash returns the layer one trie root
	RootHash() ([]byte, error)
	// SetRootHash sets root hash for layer one trie
	SetRootHash([]byte) error
	// Get returns the value in layer two
	Get([]byte, []byte) ([]byte, error)
	// Upsert upserts an item in layer two
	Upsert([]byte, []byte, []byte) error
	// Delete deletes an item in layer two
	Delete([]byte, []byte) error
}