shachain: constructors for remote vs origin

This commit is contained in:
Olaoluwa Osuntokun 2015-12-16 18:42:07 -06:00
parent ce42741daa
commit 139e63c9cf

@ -34,8 +34,15 @@ type HyperShaChain struct {
lastHash wire.ShaHash
}
// NewHyperShaChain...
func NewHyperShaChain(seed *[32]byte, deriveTo uint64) (*HyperShaChain, error) {
// NewHyperShaChain
// * used to track their pre-images
func NewHyperShaChain() *HyperShaChain {
return &HyperShaChain{lastChainIndex: 0, numValid: 0}
}
// NewHyperShaChainFromSeed...
// * used to derive your own pre-images
func NewHyperShaChainFromSeed(seed *[32]byte, deriveTo uint64) (*HyperShaChain, error) {
var shaSeed *[32]byte
// If no seed is specified, generate a new one.
@ -74,6 +81,11 @@ func derive(from, to uint64, startingHash [32]byte) [32]byte {
return nextHash
}
// canDerive...
func canDerive(from, to uint64) bool {
return ^from&to == 1
}
// getHash...
// index should be commitment #
func (h *HyperShaChain) GetHash(index uint64) (*[32]byte, error) {
@ -93,15 +105,10 @@ func (h *HyperShaChain) GetHash(index uint64) (*[32]byte, error) {
return nil, fmt.Errorf("unable to derive hash # %v", index)
}
// canDerive...
func canDerive(from, to uint64) bool {
return ^from&to == 1
}
// addHash
func (h *HyperShaChain) AddNextHash(hash [32]byte) error {
nextIdx := h.lastChainIndex + 1
// Hashes for a remote chain must be added in order.
nextIdx := h.lastChainIndex + 1
if nextIdx != h.lastChainIndex+1 || nextIdx == 0 && h.numValid != 0 {
return fmt.Errorf("shachain values must be added in order, attempted"+
"to add index %v, chain is at %v", nextIdx, h.lastChainIndex)