// Stat returns the BlobInfo for a provided blobKey. If no blob was found for
// that key, Stat returns datastore.ErrNoSuchEntity.
func Stat(c context.Context, blobKey appengine.BlobKey) (*BlobInfo, error) {
c, _ = appengine.Namespace(c, "") // Blobstore is always in the empty string namespace
dskey := datastore.NewKey(c, blobInfoKind, string(blobKey), 0, nil)
bi := &BlobInfo{
BlobKey: blobKey,
}
if err := datastore.Get(c, dskey, bi); err != nil && !isErrFieldMismatch(err) {
return nil, err
}
return bi, nil
}
// guestbookKey returns the key used for all guestbook entries.
func guestbookKey(ctx context.Context) *datastore.Key {
// The string "default_guestbook" here could be varied to have multiple guestbooks.
return datastore.NewKey(ctx, "Guestbook", "default_guestbook", 0, nil)
}