// IsValidHash checks whether a given hash is valid (b58 decodable, len > 0)
func IsValidHash(s string) bool {
out := b58.Decode(s)
if out == nil || len(out) == 0 {
return false
}
_, err := mh.Cast(out)
if err != nil {
return false
}
return true
}
func Decode(encoding, digest string) (mh.Multihash, error) {
switch encoding {
case "raw":
return mh.Cast([]byte(digest))
case "hex":
return hex.DecodeString(digest)
case "base58":
return base58.Decode(digest), nil
case "base64":
return base64.StdEncoding.DecodeString(digest)
default:
return nil, fmt.Errorf("unknown encoding: %s", encoding)
}
}
// AllKeysChan runs a query for keys from the blockstore.
// this is very simplistic, in the future, take dsq.Query as a param?
//
// AllKeysChan respects context
func (bs *blockstore) AllKeysChan(ctx context.Context) (<-chan key.Key, error) {
// KeysOnly, because that would be _a lot_ of data.
q := dsq.Query{KeysOnly: true}
// datastore/namespace does *NOT* fix up Query.Prefix
q.Prefix = BlockPrefix.String()
res, err := bs.datastore.Query(q)
if err != nil {
return nil, err
}
// this function is here to compartmentalize
get := func() (k key.Key, ok bool) {
select {
case <-ctx.Done():
return k, false
case e, more := <-res.Next():
if !more {
return k, false
}
if e.Error != nil {
return k, false
}
// need to convert to key.Key using key.KeyFromDsKey.
k = key.KeyFromDsKey(ds.NewKey(e.Key))
// key must be a multihash. else ignore it.
_, err := mh.Cast([]byte(k))
if err != nil {
return "", true
}
return k, true
}
}
output := make(chan key.Key)
go func() {
defer func() {
res.Process().Close() // ensure exit (signals early exit, too)
close(output)
}()
for {
k, ok := get()
if !ok {
return
}
if k == "" {
continue
}
select {
case <-ctx.Done():
return
case output <- k:
}
}
}()
return output, nil
}