istate

type LedgerStateManager interface {

	// LedgerInfo returns the last updated ledger info.
	LedgerInfo() *wire.LedgerInfo

	// LocalLedgerInfo returns the current local ledger.
	LocalLedgerInfo() *wire.LedgerInfo

	// GetLedgerRoot returns state's merkle tree's root hash.
	GetLedgerRoot() merkle.MerkleHash

	// GetShardHeight returns the height of the specific shrad.
	GetShardHeight(shardIndex shard.Index) int64

	// GetNewUpdate returns a temporary StateUpdate instance which can verify tx or block quickly.
	NewUpdate() (*state.Update, error)

	// ApplyUpdate apply a new update to state.
	ApplyUpdate(update *state.Update) error

	// GetUpdateWithFullBlock is similar to UpdateWithFullBlock, but it will not really update the ledger.
	GetUpdateWithFullBlock(block *wire.MsgBlock) (*state.Update, error)

	// GetUpdateWithSlimBlock is similar to GetUpdateWithFullBlock, but it updates with the slimblock rather than fullblock.
	GetUpdateWithSlimBlock(slimblock *wire.SlimBlock) (*state.Update, error)

	// It returns the available header according to the given ledgerInfo.
	GetBlockHeadersToAppend(ledgerInfo *wire.LedgerInfo) ([]*wire.BlockHeader, error)
}