image.py 文件源码

def __get_catalog(self, name):
                """Private method to retrieve catalog; this bypasses the
                normal automatic caching (unless the image hasn't been
                upgraded yet)."""

                croot = os.path.join(self._statedir, name)
                try:
                        os.makedirs(croot)
                except EnvironmentError as e:
                        if e.errno in (errno.EACCES, errno.EROFS):
                                # Allow operations to work for
                                # unprivileged users.
                                croot = None
                        elif e.errno != errno.EEXIST:
                                raise

                # batch_mode is set to True here as any operations that modify
                # the catalogs (add or remove entries) are only done during an
                # image upgrade or metadata refresh.  In both cases, the catalog
                # is resorted and finalized so this is always safe to use.
                cat = pkg.catalog.Catalog(batch_mode=True, meta_root=croot,
                    sign=False, file_root=self.imgdir)
                return cat