// Errors returned are:
// os.ErrNotExist -- blob not found
// os.ErrInvalid -- not JSON or a camli schema blob
func (fs *CamliFileSystem) fetchSchemaSuperset(br *blobref.BlobRef) (*schema.Superset, error) {
blobStr := br.String()
if ss, ok := fs.blobToSchema.Get(blobStr); ok {
return ss.(*schema.Superset), nil
}
rsc, _, err := fs.fetcher.Fetch(br)
if err != nil {
return nil, err
}
defer rsc.Close()
jd := json.NewDecoder(rsc)
ss := new(schema.Superset)
err = jd.Decode(ss)
if err != nil {
log.Printf("Error parsing %s as schema blob: %v", br, err)
return nil, os.ErrInvalid
}
if ss.Type == "" {
log.Printf("blob %s is JSON but lacks camliType", br)
return nil, os.ErrInvalid
}
ss.BlobRef = br
fs.blobToSchema.Add(blobStr, ss)
return ss, nil
}
