19 var hashJsonLengthErr = errors.New("common: unmarshalJSON failed: hash must be exactly 32 bytes")
25 func BytesToHash(b []byte) Hash {
31 func StringToHash(s string) Hash { return BytesToHash([]byte(s)) }
32 func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
34 // Don't use the default 'String' method in case we want to overwrite
36 // Get the string representation of the underlying hash
37 func (h Hash) Str() string { return string(h[:]) }
38 func (h Hash) Bytes() []byte { return h[:] }
39 func (h Hash) Hex() string { return "0x" + Bytes2Hex(h[:]) }
41 // UnmarshalJSON parses a hash in its hex from to a hash.
42 func (h *Hash) UnmarshalJSON(input []byte) error {
44 if length >= 2 && input[0] == '"' && input[length-1] == '"' {
45 input = input[1 : length-1]
47 // strip "0x" for length check
48 if len(input) > 1 && strings.ToLower(string(input[:2])) == "0x" {
52 // validate the length of the input hash
53 if len(input) != HashLength*2 {
54 return hashJsonLengthErr
56 h.SetBytes(FromHex(string(input)))
60 // Serialize given hash to JSON
61 func (h Hash) MarshalJSON() ([]byte, error) {
62 return json.Marshal(h.Hex())
65 // Sets the hash to the value of b. If b is larger than len(h) it will panic
66 func (h *Hash) SetBytes(b []byte) {
68 b = b[len(b)-HashLength:]
71 copy(h[HashLength-len(b):], b)
75 func (h *Hash) Set(other Hash) {
76 for i, v := range other {
81 // Generate implements testing/quick.Generator.
82 func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
83 m := rand.Intn(len(h))
84 for i := len(h) - 1; i > m; i-- {
85 h[i] = byte(rand.Uint32())
87 return reflect.ValueOf(h)
90 func EmptyHash(h Hash) bool {