state

type BlockState interface {
	GetBlock(blkID ids.ID) (block.Block, error)
	PutBlock(blk block.Block) error
	DeleteBlock(blkID ids.ID) error
}

type ChainState interface {
	SetLastAccepted(blkID ids.ID) error
	DeleteLastAccepted() error
	GetLastAccepted() (ids.ID, error)
}

type HeightIndex interface {
	HeightIndexWriter
	HeightIndexGetter
}

type HeightIndexGetter interface {
	// GetMinimumHeight return the smallest height of an indexed blockID. If
	// there are no indexed blockIDs, ErrNotFound will be returned.
	GetMinimumHeight() (uint64, error)
	GetBlockIDAtHeight(height uint64) (ids.ID, error)

	// Fork height is stored when the first post-fork block/option is accepted.
	// Before that, fork height won't be found.
	GetForkHeight() (uint64, error)
}

type HeightIndexWriter interface {
	SetForkHeight(height uint64) error
	SetBlockIDAtHeight(height uint64, blkID ids.ID) error
	DeleteBlockIDAtHeight(height uint64) error
}

type State interface {
	ChainState
	BlockState
	HeightIndex
}