import numpy
from urllib.parse import ParseResult
from typing import Any, Dict, Union, Optional
from .uri import parse_query, parse_uri, join_uri, uri_as_string
from ..registration import Registered
from ..hashing import UniversalHash
from ..hashing import HasUhash
[docs]
class PersistenceError(RuntimeError):
pass
[docs]
class UriNotFoundError(PersistenceError):
pass
[docs]
class DataUri(HasUhash):
def __init__(self, uri: str, uhash: Union[UniversalHash, str]):
if isinstance(uri, numpy.ndarray):
uri = uri.item()
if isinstance(uhash, numpy.ndarray):
uhash = uhash.item()
self.__uri = uri_as_string(uri)
if isinstance(uhash, str):
uhash = UniversalHash(uhash)
self.__uhash = uhash
def __repr__(self):
return f"{type(self).__name__}({self.__uri})"
def __str__(self):
return self.__uri
[docs]
def parse(self) -> ParseResult:
return parse_uri(self.__uri)
def __eq__(self, other):
if isinstance(other, str):
return str(self) == str(other)
elif isinstance(other, DataUri):
return str(self) == str(other) and self.uhash == other.uhash
else:
return False
def __copy__(self):
return type(self)(self.__uri, self.__uhash)
@property
def uhash(self) -> UniversalHash:
return self.__uhash
[docs]
def serialize(self) -> Dict[str, str]:
return {"uri": self.__uri, "uhash": str(self.uhash)}
[docs]
@classmethod
def deserialize(cls, data: Dict[str, str]):
if not isinstance(data, dict):
return None
try:
uri = data["uri"]
uhash = data["uhash"]
except KeyError:
return None
return cls(uri, uhash)
[docs]
class DataProxy(Registered, HasUhash, register=False):
SCHEME = NotImplemented
"""name of the DataProxy scheme like json or nexus"""
def __init__(
self,
uri: Optional[DataUri] = None,
root_uri: Optional[str] = None,
relative_uri: Optional[str] = None,
uhash_source: Optional[Union[UniversalHash, HasUhash]] = None,
):
"""Either the URI is provided or the root + relative URI with a uhash source (the URI can be derived from those)"""
self.__parsed_root_uri = None
self.__fixed_uri = uri
self.__uhash_source = uri
if uri is None:
self.__uhash_source = uhash_source
else:
root_uri = str(uri)
relative_uri = None
if root_uri:
parsed_root_uri = parse_uri(root_uri)
if relative_uri:
parsed_root_uri = join_uri(parsed_root_uri, relative_uri)
self.__parsed_root_uri = parsed_root_uri
def __repr__(self):
uri = self.uri
if uri is None:
return super().__repr__()
else:
return f"{super().__repr__()}(uri='{uri}')"
[docs]
@classmethod
def instantiate(
cls,
scheme: Optional[str] = None,
uri: Optional[DataUri] = None,
uhash_source: Optional[Union[UniversalHash, HasUhash]] = None,
root_uri: Optional[str] = None,
relative_uri: Optional[str] = None,
):
if uri is not None:
scheme = uri.parse().scheme
elif isinstance(root_uri, DataProxy):
scheme = root_uri.SCHEME
elif isinstance(root_uri, DataUri):
scheme = root_uri.parse().scheme
for subclass in cls.get_subclasses():
if subclass.SCHEME == scheme:
return subclass(
uri=uri,
uhash_source=uhash_source,
root_uri=root_uri,
relative_uri=relative_uri,
)
raise ValueError(f"Data proxy scheme '{scheme}' is not supported")
[docs]
def serialize(self) -> Dict[str, str]:
return self.uri.serialize()
[docs]
@classmethod
def deserialize(self, data: Dict[str, str]):
uri = DataUri.deserialize(data)
if uri is None:
return None
return self.instantiate(uri=uri)
@property
def uhash(self) -> Optional[UniversalHash]:
if self.is_fixed_uri:
return self.__fixed_uri.uhash
elif isinstance(self.__uhash_source, HasUhash):
return self.__uhash_source.uhash
elif isinstance(self.__uhash_source, UniversalHash):
return self.__uhash_source
else:
return None
@property
def identifier(self) -> Optional[str]:
"""Return identifier DataProxy to be used as a string"""
uhash = self.uhash
if uhash is None:
return None
return str(uhash)
@property
def parsed_root_uri(self) -> Optional[ParseResult]:
return self.__parsed_root_uri
@property
def root_uri_query(self) -> dict:
parsed_root_uri = self.parsed_root_uri
if parsed_root_uri:
return parse_query(parsed_root_uri)
return dict()
@property
def is_fixed_uri(self) -> bool:
return self.__fixed_uri is not None
@property
def uri(self) -> Optional[DataUri]:
"""
Return an Unified Resource Identifier. Defined as:
URI = scheme ":" "//" path ["?" query] ["#" fragment]
see https://en.wikipedia.org/wiki/Uniform_Resource_Identifier
.. warning:: query can be ?path= which is different from path
"""
if self.is_fixed_uri:
return self.__fixed_uri
return self._generate_uri()
def _generate_uri(self) -> Optional[DataUri]:
"""Generate a URI based on the root URI and the universal hash"""
raise NotImplementedError
[docs]
def exists(self) -> bool:
"""return True if the data exists"""
raise NotImplementedError
[docs]
def load(self, raise_error: bool = True) -> Any:
"""Load data from the uri"""
raise NotImplementedError
[docs]
def dump(self, data: Any) -> bool:
"""Dump data to the uri"""
raise NotImplementedError