"""lru_cache on 'roids."""
from . import digest
from .state import (
cache,
meta,
tags,
project,
)
from .wrapper import fleche, Ignored, Required
[docs]
def D(value) -> digest.Digest:
"""
Convenience wrapper to create a Digest from a value.
If given a non-empty string that is a valid hexadecimal string of at most
:data:`~fleche.digest.DIGEST_LENGTH` characters, wraps it in a :class:`~fleche.digest.Digest`
directly (allowing short hex prefixes for use with :meth:`~fleche.digest.Digest.expand`).
For any other value — including strings that are not valid hex digests — computes the digest.
.. warning::
Passing an arbitrary string to ``D()`` will silently compute its digest rather than
treating the string as a digest identifier. Only strings that consist entirely of
hexadecimal characters (``0-9``, ``a-f``, ``A-F``) and are no longer than
:data:`~fleche.digest.DIGEST_LENGTH` characters are used verbatim. If you intend to
look up a cached value by its digest string, make sure the string you pass satisfies
those constraints; otherwise you will get the digest *of* the string itself, which is
almost certainly not what you want.
Digests passed as arguments to @fleche decorated functions are automatically expanded
to their cached values.
"""
if isinstance(value, str) and 0 < len(value) <= digest.DIGEST_LENGTH and all(c in "0123456789abcdefABCDEF" for c in value):
return digest.Digest(value)
return digest.digest(value)
__all__ = [
"fleche",
"cache",
"meta",
"tags",
"project",
"Ignored",
"Required",
"D",
]