56 lines
910 B
Go
56 lines
910 B
Go
package cid
|
|
|
|
import (
|
|
mh "github.com/multiformats/go-multihash"
|
|
)
|
|
|
|
type Format interface {
|
|
Sum(data []byte) (*Cid, error)
|
|
}
|
|
|
|
type FormatV0 struct{}
|
|
|
|
type FormatV1 struct {
|
|
Codec uint64
|
|
HashFun uint64
|
|
HashLen int // HashLen <= 0 means the default length
|
|
}
|
|
|
|
func PrefixToFormat(p Prefix) Format {
|
|
if p.Version == 0 {
|
|
return FormatV0{}
|
|
}
|
|
mhLen := p.MhLength
|
|
if p.MhType == mh.ID {
|
|
mhLen = 0
|
|
}
|
|
if mhLen < 0 {
|
|
mhLen = 0
|
|
}
|
|
return FormatV1{
|
|
Codec: p.Codec,
|
|
HashFun: p.MhType,
|
|
HashLen: mhLen,
|
|
}
|
|
}
|
|
|
|
func (p FormatV0) Sum(data []byte) (*Cid, error) {
|
|
hash, err := mh.Sum(data, mh.SHA2_256, -1)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return NewCidV0(hash), nil
|
|
}
|
|
|
|
func (p FormatV1) Sum(data []byte) (*Cid, error) {
|
|
mhLen := p.HashLen
|
|
if mhLen <= 0 {
|
|
mhLen = -1
|
|
}
|
|
hash, err := mh.Sum(data, p.HashFun, mhLen)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return NewCidV1(p.Codec, hash), nil
|
|
}
|