types

type ImportEntry struct {
	StoreKey string
	Key      []byte
	Value    []byte
}

type StateStore interface {
	Get(storeKey string, version int64, key []byte) ([]byte, error)
	Has(storeKey string, version int64, key []byte) (bool, error)
	Iterator(storeKey string, version int64, start, end []byte) (types.Iterator, error)
	ReverseIterator(storeKey string, version int64, start, end []byte) (types.Iterator, error)
	GetLatestVersion() (int64, error)
	SetLatestVersion(version int64) error

	// ApplyChangeset Persist the change set of a block,
	// the `changeSet` should be ordered by (storeKey, key),
	// the version should be latest version plus one.
	ApplyChangeset(version int64, cs *proto.NamedChangeSet) error

	// Import the initial state of the store
	Import(version int64, ch <-chan ImportEntry, numWorkers int) error

	// Prune attempts to prune all versions up to and including the provided
	// version argument. The operation should be idempotent. An error should be
	// returned upon failure.
	Prune(version int64) error

	// Closer releases associated resources. It should NOT be idempotent. It must
	// only be called once and any call after may panic.
	io.Closer
}