interfaces: introduce and use a protocol class for the `base85` module
See
f2832de2a46c for details when this was done for the `bdiff` module.
It looks like PEP-688 removed the special casing of `bytes` being a standin
for any type of `ByteString`, and defines a `typing.Buffer` class (with a
backport in `typing_extensions` for Python prior to 3.12). There's been a lot
of churn in this area with pytype, but recent versions of pytype and PyCharm
recognize this, and e.g. have `mercurial.node.hex()` defined as:
from typing_extensions import Buffer
def hex(data: Buffer, sep: str | bytes = ..., bytes_per_sep: int = ...) -> bytes
This covers `bytes`, `bytearray`, and `memoryview` by default. Both of the C
functions here use `y#` to parse the arguments, which means the arg is a
byte-like object[2], so the args would appear to be better typed as `Buffer`.
However, pytype has a bug that prevents using this from `typing_extensions`[3],
and mypy complained `Unsupported left operand type for + ("memoryview")` in the
pure module on line 37 (meaning it's only a subset of `Buffer`). So hold off on
changing any of that for now.
[1] https://peps.python.org/pep-0688/#no-special-meaning-for-bytes
[2] https://docs.python.org/3/glossary.html#term-bytes-like-object
[3] https://github.com/google/pytype/issues/1772
--- a/mercurial/interfaces/modules.py Fri Oct 04 23:09:56 2024 -0400
+++ b/mercurial/interfaces/modules.py Fri Oct 04 23:21:41 2024 -0400
@@ -23,6 +23,16 @@
"""The signature of `bdiff.blocks()` and `bdiff.xdiffblocks()`."""
+class Base85(Protocol):
+ """A Protocol class for the various base85 module implementations."""
+
+ def b85encode(self, text: bytes, pad: bool = False) -> bytes:
+ """encode text in base85 format"""
+
+ def b85decode(self, text: bytes) -> bytes:
+ """decode base85-encoded text"""
+
+
class BDiff(Protocol):
"""A Protocol class for the various bdiff module implementations."""
--- a/mercurial/util.py Fri Oct 04 23:09:56 2024 -0400
+++ b/mercurial/util.py Fri Oct 04 23:21:41 2024 -0400
@@ -70,6 +70,9 @@
typelib,
urllibcompat,
)
+from .interfaces import (
+ modules as intmod,
+)
from .utils import (
compression,
hashutil,
@@ -87,7 +90,7 @@
]
-base85 = policy.importmod('base85')
+base85: intmod.Base85 = policy.importmod('base85')
osutil = policy.importmod('osutil')
b85decode = base85.b85decode