Merge pull request #201 from Bytom/v0.1

[bytom/vapor.git] / vendor / github.com / bytom / protocol / bc / hash.go

diff --git a/vendor/github.com/bytom/protocol/bc/hash.go b/vendor/github.com/bytom/protocol/bc/hash.go
new file mode 100644 (file)
index 0000000..a142030
--- /dev/null
+++ b/vendor/github.com/bytom/protocol/bc/hash.go
@@ -0,0 +1,103 @@
+package bc
+
+import (
+       "bytes"
+       "encoding/binary"
+       "encoding/hex"
+       "encoding/json"
+       "fmt"
+       "io"
+
+       "golang.org/x/crypto/sha3"
+)
+
+// EmptyStringHash represents a 256-bit hash.
+var EmptyStringHash = NewHash(sha3.Sum256(nil))
+
+// NewHash convert the input byte array to hash
+func NewHash(b32 [32]byte) (h Hash) {
+       h.V0 = binary.BigEndian.Uint64(b32[0:8])
+       h.V1 = binary.BigEndian.Uint64(b32[8:16])
+       h.V2 = binary.BigEndian.Uint64(b32[16:24])
+       h.V3 = binary.BigEndian.Uint64(b32[24:32])
+       return h
+}
+
+// Byte32 return the byte array representation
+func (h Hash) Byte32() (b32 [32]byte) {
+       binary.BigEndian.PutUint64(b32[0:8], h.V0)
+       binary.BigEndian.PutUint64(b32[8:16], h.V1)
+       binary.BigEndian.PutUint64(b32[16:24], h.V2)
+       binary.BigEndian.PutUint64(b32[24:32], h.V3)
+       return b32
+}
+
+// MarshalText satisfies the TextMarshaler interface.
+// It returns the bytes of h encoded in hex,
+// for formats that can't hold arbitrary binary data.
+// It never returns an error.
+func (h Hash) MarshalText() ([]byte, error) {
+       b := h.Byte32()
+       v := make([]byte, 64)
+       hex.Encode(v, b[:])
+       return v, nil
+}
+
+// UnmarshalText satisfies the TextUnmarshaler interface.
+// It decodes hex data from b into h.
+func (h *Hash) UnmarshalText(v []byte) error {
+       var b [32]byte
+       if len(v) != 64 {
+               return fmt.Errorf("bad length hash string %d", len(v))
+       }
+       _, err := hex.Decode(b[:], v)
+       *h = NewHash(b)
+       return err
+}
+
+// UnmarshalJSON satisfies the json.Unmarshaler interface.
+// If b is a JSON-encoded null, it copies the zero-value into h. Othwerwise, it
+// decodes hex data from b into h.
+func (h *Hash) UnmarshalJSON(b []byte) error {
+       if bytes.Equal(b, []byte("null")) {
+               *h = Hash{}
+               return nil
+       }
+       var s string
+       if err := json.Unmarshal(b, &s); err != nil {
+               return err
+       }
+       return h.UnmarshalText([]byte(s))
+}
+
+// Bytes returns the byte representation
+func (h Hash) Bytes() []byte {
+       b32 := h.Byte32()
+       return b32[:]
+}
+
+// WriteTo satisfies the io.WriterTo interface.
+func (h Hash) WriteTo(w io.Writer) (int64, error) {
+       n, err := w.Write(h.Bytes())
+       return int64(n), err
+}
+
+// ReadFrom satisfies the io.ReaderFrom interface.
+func (h *Hash) ReadFrom(r io.Reader) (int64, error) {
+       var b32 [32]byte
+       n, err := io.ReadFull(r, b32[:])
+       if err != nil {
+               return int64(n), err
+       }
+       *h = NewHash(b32)
+       return int64(n), nil
+}
+
+// IsZero tells whether a Hash pointer is nil or points to an all-zero
+// hash.
+func (h *Hash) IsZero() bool {
+       if h == nil {
+               return true
+       }
+       return *h == Hash{}
+}