def __init__(self, schema: Optional[Mapping[str, Any]]) -> None:
self._schema = schema
if schema is None:
self._string = ""
self._validate_row = validate_bytes
self.encode_row = NOOPCodec({}).encode
self.decode_row = NOOPCodec({}).decode
self.empty_value = b""
else:
try:
TSKITMetadataSchemaValidator.check_schema(schema)
except jsonschema.exceptions.SchemaError as ve:
raise exceptions.MetadataSchemaValidationError(str(ve)) from ve
try:
codec_cls = codec_registry[schema["codec"]]
except KeyError:
raise exceptions.MetadataSchemaValidationError(
f"Unrecognised metadata codec '{schema['codec']}'. "
f"Valid options are {str(list(codec_registry.keys()))}.")
# Codecs can modify the schema, for example to set defaults as the validator
# does not.
schema = codec_cls.modify_schema(schema)
codec_instance = codec_cls(schema)
self._string = tskit.canonical_json(schema)
self._validate_row = TSKITMetadataSchemaValidator(schema).validate
self.encode_row = codec_instance.encode
self.decode_row = codec_instance.decode
# If None is allowed by the schema it gets used even in the presence of
# default and required values.
if "type" in schema and "null" in schema["type"]:
self.empty_value = None
else:
self.empty_value = {}
def encode(self, obj: Any) -> bytes:
return tskit.canonical_json(obj).encode()
def encode(self, obj: Any) -> bytes:
try:
return tskit.canonical_json(obj).encode()
except TypeError as e:
raise exceptions.MetadataEncodingError(
f"Could not encode metadata of type {str(e).split()[3]}")