status-go/vendor/github.com/ipfs/go-cid/builder.go

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2019-06-09 07:24:20 +00:00
package cid
import (
mh "github.com/multiformats/go-multihash"
)
type Builder interface {
Sum(data []byte) (Cid, error)
GetCodec() uint64
WithCodec(uint64) Builder
}
type V0Builder struct{}
type V1Builder struct {
Codec uint64
MhType uint64
MhLength int // MhLength <= 0 means the default length
}
func (p Prefix) GetCodec() uint64 {
return p.Codec
}
func (p Prefix) WithCodec(c uint64) Builder {
if c == p.Codec {
return p
}
p.Codec = c
if c != DagProtobuf {
p.Version = 1
}
return p
}
func (p V0Builder) Sum(data []byte) (Cid, error) {
hash, err := mh.Sum(data, mh.SHA2_256, -1)
if err != nil {
return Undef, err
}
return NewCidV0(hash), nil
}
func (p V0Builder) GetCodec() uint64 {
return DagProtobuf
}
func (p V0Builder) WithCodec(c uint64) Builder {
if c == DagProtobuf {
return p
}
return V1Builder{Codec: c, MhType: mh.SHA2_256}
}
func (p V1Builder) Sum(data []byte) (Cid, error) {
mhLen := p.MhLength
if mhLen <= 0 {
mhLen = -1
}
hash, err := mh.Sum(data, p.MhType, mhLen)
if err != nil {
return Undef, err
}
return NewCidV1(p.Codec, hash), nil
}
func (p V1Builder) GetCodec() uint64 {
return p.Codec
}
func (p V1Builder) WithCodec(c uint64) Builder {
p.Codec = c
return p
}