FedP2P/types/infohash/infohash.go

81 lines
1.4 KiB
Go

package infohash
import (
"crypto/sha1"
"encoding"
"encoding/hex"
"fmt"
)
const Size = 20
// 20-byte SHA1 hash used for info and pieces.
type T [Size]byte
var _ fmt.Formatter = (*T)(nil)
func (t T) Format(f fmt.State, c rune) {
// TODO: I can't figure out a nice way to just override the 'x' rune, since it's meaningless
// with the "default" 'v', or .String() already returning the hex.
f.Write([]byte(t.HexString()))
}
func (t T) Bytes() []byte {
return t[:]
}
func (t T) AsString() string {
return string(t[:])
}
func (t T) String() string {
return t.HexString()
}
func (t T) HexString() string {
return fmt.Sprintf("%x", t[:])
}
func (t *T) FromHexString(s string) (err error) {
if len(s) != 2*Size {
err = fmt.Errorf("hash hex string has bad length: %d", len(s))
return
}
n, err := hex.Decode(t[:], []byte(s))
if err != nil {
return
}
if n != Size {
panic(n)
}
return
}
var (
_ encoding.TextUnmarshaler = (*T)(nil)
_ encoding.TextMarshaler = T{}
)
func (t *T) UnmarshalText(b []byte) error {
return t.FromHexString(string(b))
}
func (t T) MarshalText() (text []byte, err error) {
return []byte(t.HexString()), nil
}
func FromHexString(s string) (h T) {
err := h.FromHexString(s)
if err != nil {
panic(err)
}
return
}
func HashBytes(b []byte) (ret T) {
hasher := sha1.New()
hasher.Write(b)
copy(ret[:], hasher.Sum(nil))
return
}