Source code for asdf.resource

Support for plugins that provide access to resources such
as schemas.

import pkgutil
from import Mapping

from asdf_standard import DirectoryResourceMapping as _DirectoryResourceMapping

from .util import get_class_name

__all__ = [

[docs] class DirectoryResourceMapping(_DirectoryResourceMapping): """ A resource mapping that reads resource content from a directory or directory tree. See :class:`~asdf_standard.resource.DirectoryResourceMapping` for details. """
[docs] class ResourceMappingProxy(Mapping): """ Wrapper around a resource mapping that carries additional information on the package that provided the mapping. """
[docs] @classmethod def maybe_wrap(cls, delegate): if isinstance(delegate, ResourceMappingProxy): return delegate return ResourceMappingProxy(delegate)
def __init__(self, delegate, package_name=None, package_version=None): if not isinstance(delegate, Mapping): msg = "Resource mapping must implement the Mapping interface" raise TypeError(msg) self._delegate = delegate self._package_name = package_name self._package_version = package_version self._class_name = get_class_name(delegate) def __getitem__(self, uri): return self._delegate.__getitem__(uri) def __len__(self): return self._delegate.__len__() def __iter__(self): return self._delegate.__iter__() @property def delegate(self): """ Get the wrapped mapping instance. Returns ------- """ return self._delegate @property def package_name(self): """ Get the name of the Python package that provided this mapping. Returns ------- str or None `None` if the mapping was added at runtime. """ return self._package_name @property def package_version(self): """ Get the version of the Python package that provided the mapping. Returns ------- str or None `None` if the mapping was added at runtime. """ return self._package_version @property def class_name(self): """ " Get the fully qualified class name of the mapping. Returns ------- str """ return self._class_name def __eq__(self, other): if isinstance(other, ResourceMappingProxy): return other.delegate is self.delegate return False def __hash__(self): return hash(id(self.delegate)) def __repr__(self): if self.package_name is not None: package_description = f"{self.package_name}=={self.package_version}" else: package_description = "(none)" return f"<ResourceMappingProxy class: {self.class_name} package: {package_description} len: {len(self)}>"
[docs] class ResourceManager(Mapping): """ Wraps multiple resource mappings into a single interface with some friendlier error handling. Parameters ---------- resource_mappings : iterable of Underlying resource mappings. In the case of a duplicate URI, the first mapping takes precedence. """ def __init__(self, resource_mappings): self._resource_mappings = resource_mappings self._mappings_by_uri = {} for mapping in resource_mappings: for uri in mapping: if uri not in self._mappings_by_uri: self._mappings_by_uri[uri] = mapping def __getitem__(self, uri): if uri not in self._mappings_by_uri: msg = f"Resource unavailable for URI: {uri}" raise KeyError(msg) content = self._mappings_by_uri[uri][uri] if isinstance(content, str): content = content.encode("utf-8") return content def __len__(self): return len(self._mappings_by_uri) def __iter__(self): yield from self._mappings_by_uri def __contains__(self, uri): # Implement __contains__ only for efficiency. return uri in self._mappings_by_uri def __repr__(self): return f"<ResourceManager len: {self.__len__()}>"
_JSONSCHEMA_URI_TO_FILENAME = { "": "draft4.json", }
[docs] class JsonschemaResourceMapping(Mapping): """ Resource mapping that fetches metaschemas from the jsonschema package. """ def __getitem__(self, uri): filename = _JSONSCHEMA_URI_TO_FILENAME[uri] return pkgutil.get_data("asdf._jsonschema", f"schemas/{filename}") def __len__(self): return len(_JSONSCHEMA_URI_TO_FILENAME) def __iter__(self): yield from _JSONSCHEMA_URI_TO_FILENAME def __repr__(self): return "JsonschemaResourceMapping()"