blobstore/blobstore.go
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
}
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
}
// Stat returns the BlobInfo for a provided blobKey. If no blob was found for
// that key, Stat returns datastore.ErrNoSuchEntity.