hash

Documentation

Index

• func HashLess(h1, h2 Hash) bool
• func HashXORDistance(h1, h2 Hash) *big.Int
• func PeerIDFromHash(h Hash) (id peer.ID)
• func XOR(a, b []byte) []byte
• func ZeroPrefixLen(id []byte) int
• type Hash
  • func HashFromBytes(b []byte) (h Hash, err error)
  • func HashFromPeerID(id peer.ID) (h Hash)
  • func NewHash(s string) (h Hash, err error)
  • func NullHash() (h Hash)
  • func SortByDistance(center Hash, toSort []Hash) []Hash
  • func (h *Hash) Clone() (hash Hash)
  • func (h *Hash) Equal(h2 *Hash) bool
  • func (h *Hash) IsNullHash() bool
  • func (h *Hash) MarshalHash(writer io.Writer) (err error)
  • func (h Hash) String() string
  • func (h *Hash) Sum(hc HashSpec, data []byte) (err error)
  • func (h *Hash) UnmarshalHash(reader io.Reader) (err error)
• type HashDistance
• type HashSorterArr
  • func (p HashSorterArr) Len() int
  • func (p HashSorterArr) Less(a, b int) bool
  • func (p HashSorterArr) Swap(a, b int)
• type HashSpec

Functions

func HashLess

func HashLess(h1, h2 Hash) bool

Less returns whether the first key is smaller than the second.

func HashXORDistance

func HashXORDistance(h1, h2 Hash) *big.Int

Distance returns the distance metric between two hashes

func PeerIDFromHash

func PeerIDFromHash(h Hash) (id peer.ID)

PeerIDFromHash copy the bytes from a hash to a peer ID. Hashes and peer ID's are the exact same format, a multihash. NOTE: assumes that the multihash is valid

func XOR

func XOR(a, b []byte) []byte

XOR takes two byte slices, XORs them together, returns the resulting slice. taken from https://github.com/ipfs/go-ipfs-util/blob/master/util.go

func ZeroPrefixLen

func ZeroPrefixLen(id []byte) int

ZeroPrefixLen returns the number of consecutive zeroes in a byte slice.

Types

type Hash

type Hash struct {
	H mh.Multihash
}

Hash of Entry's Content

func HashFromBytes

func HashFromBytes(b []byte) (h Hash, err error)

HashFromBytes cast a byte slice to Hash type, and validate the id to make sure it is a multihash.

func HashFromPeerID

func HashFromPeerID(id peer.ID) (h Hash)

HashFromPeerID copy the bytes from a peer ID to Hash. Hashes and peer ID's are the exact same format, a multihash. NOTE: assumes that the multihash is valid

func NewHash

func NewHash(s string) (h Hash, err error)

NewHash builds a Hash from a b58 string encoded hash

func NullHash

func NullHash() (h Hash)

NullHash builds a null valued hash

func SortByDistance

func SortByDistance(center Hash, toSort []Hash) []Hash

SortByDistance takes a center Hash, and a list of Hashes toSort. It returns a new list, where the Hashes toSort have been sorted by their distance to the center Hash.

func (*Hash) Clone

func (h *Hash) Clone() (hash Hash)

Clone returns a copy of a hash

func (*Hash) Equal

func (h *Hash) Equal(h2 *Hash) bool

Equal checks to see if two hashes have the same value

func (*Hash) IsNullHash

func (h *Hash) IsNullHash() bool

IsNullHash checks to see if this hash's value is the null hash

func (*Hash) MarshalHash

func (h *Hash) MarshalHash(writer io.Writer) (err error)

MarshalHash writes a hash to a binary stream

func (Hash) String

func (h Hash) String() string

String encodes a hash to a human readable string

func (*Hash) Sum

func (h *Hash) Sum(hc HashSpec, data []byte) (err error)

Sum builds a digest according to the specs in the Holochain

func (*Hash) UnmarshalHash

func (h *Hash) UnmarshalHash(reader io.Reader) (err error)

UnmarshalHash reads a hash from a binary stream

type HashDistance

type HashDistance struct {
	Hash     interface{}
	Distance *big.Int
}

hashDistance helper struct for sorting by distance which pre-caches the distance to center so as not to recalculate it on every sort comparison.

type HashSorterArr

type HashSorterArr []*HashDistance

func (HashSorterArr) Len

func (p HashSorterArr) Len() int

func (HashSorterArr) Less

func (p HashSorterArr) Less(a, b int) bool

func (HashSorterArr) Swap

func (p HashSorterArr) Swap(a, b int)

type HashSpec

type HashSpec struct {
	Code   uint64
	Length int
}

HashSpec holds the info that tells what kind of hash this is