Files
ucan/pkg/container/reader.go
2024-10-02 13:43:17 +02:00

174 lines
3.3 KiB
Go

package container
import (
"compress/flate"
"compress/gzip"
"encoding/base64"
"fmt"
"io"
"github.com/ipfs/go-cid"
cbor "github.com/ipfs/go-ipld-cbor"
"github.com/ipld/go-ipld-prime"
"github.com/ipld/go-ipld-prime/codec/dagcbor"
"github.com/ipld/go-ipld-prime/datamodel"
"github.com/ucan-wg/go-ucan/token"
"github.com/ucan-wg/go-ucan/token/delegation"
"github.com/ucan-wg/go-ucan/token/invocation"
)
var ErrNotFound = fmt.Errorf("not found")
type Reader map[cid.Cid]token.Token
func (ctn Reader) GetToken(cid cid.Cid) (token.Token, error) {
tkn, ok := ctn[cid]
if !ok {
return nil, ErrNotFound
}
return tkn, nil
}
func (ctn Reader) GetDelegation(cid cid.Cid) (*delegation.Token, error) {
tkn, err := ctn.GetToken(cid)
if err != nil {
return nil, err
}
if tkn, ok := tkn.(*delegation.Token); ok {
return tkn, nil
}
return nil, fmt.Errorf("not a delegation token")
}
func (ctn Reader) GetInvocation() (*invocation.Token, error) {
for _, t := range ctn {
if inv, ok := t.(*invocation.Token); ok {
return inv, nil
}
}
return nil, ErrNotFound
}
func FromCar(r io.Reader) (Reader, error) {
_, it, err := readCar(r)
if err != nil {
return nil, err
}
ctn := make(Reader)
for block, err := range it {
if err != nil {
return nil, err
}
err = ctn.addToken(block.data)
if err != nil {
return nil, err
}
}
return ctn, nil
}
func FromCarBase64(r io.Reader) (Reader, error) {
return FromCar(base64.NewDecoder(base64.StdEncoding, r))
}
func FromCarGzip(r io.Reader) (Reader, error) {
r2, err := gzip.NewReader(r)
if err != nil {
return nil, err
}
defer r2.Close()
return FromCar(r2)
}
func FromCarGzipBase64(r io.Reader) (Reader, error) {
return FromCarGzip(base64.NewDecoder(base64.StdEncoding, r))
}
func FromCbor(r io.Reader) (Reader, error) {
var raw [][]byte
err := cbor.DecodeReader(r, &raw)
if err != nil {
return nil, err
}
ctn := make(Reader, len(raw))
for _, data := range raw {
err = ctn.addToken(data)
if err != nil {
return nil, err
}
}
return ctn, nil
}
func FromCbor2(r io.Reader) (Reader, error) {
n, err := ipld.DecodeStreaming(r, dagcbor.Decode)
if err != nil {
return nil, err
}
if n.Kind() != datamodel.Kind_List {
return nil, fmt.Errorf("not a list")
}
ctn := make(Reader, n.Length())
it := n.ListIterator()
for !it.Done() {
_, val, err := it.Next()
if err != nil {
return nil, err
}
data, err := val.AsBytes()
if err != nil {
return nil, err
}
err = ctn.addToken(data)
if err != nil {
return nil, err
}
}
return ctn, nil
}
func FromCborBase64(r io.Reader) (Reader, error) {
return FromCbor(base64.NewDecoder(base64.StdEncoding, r))
}
func FromCborGzip(r io.Reader) (Reader, error) {
r2, err := gzip.NewReader(r)
if err != nil {
return nil, err
}
defer r2.Close()
return FromCbor(r2)
}
func FromCborGzipBase64(r io.Reader) (Reader, error) {
return FromCborGzip(base64.NewDecoder(base64.StdEncoding, r))
}
func FromCborFlate(r io.Reader) (Reader, error) {
r2 := flate.NewReader(r)
defer r2.Close()
return FromCbor(r2)
}
func FromCborFlateBase64(r io.Reader) (Reader, error) {
return FromCborFlate(base64.NewDecoder(base64.StdEncoding, r))
}
func (ctn Reader) addToken(data []byte) error {
tkn, c, err := token.FromSealed(data)
if err != nil {
return err
}
ctn[c] = tkn
return nil
}