builder.go

package module

import (
	"github.com/onflow/flow-go/model/flow"
)

// Builder represents an abstracted block construction module that can be used
// in more than one consensus algorithm. The resulting block is consistent
// within itself and can be wrapped with additional consensus information such
// as QCs.
type Builder interface {

	// BuildOn generates a new payload that is valid with respect to the parent
	// being built upon, with the view being provided by the consensus algorithm.
	// The builder stores the block and validates it against the protocol state
	// before returning it.
	//
	// NOTE: Since the block is stored within Builder, HotStuff MUST propose the
	// block once BuildOn successfully returns.
	BuildOn(parentID flow.Identifier, setter func(*flow.Header) error, sign func(*flow.Header) error) (*flow.Header, error)
}