annotate mercurial/cext/bdiff.pyi @ 50317:af776c3d5c3e stable

debugdeltachain: stop summing the same chain over and over

Before this patch, delta chain size was computed from scratch for each chain,
disregarding the fact very likely already computed the same of length-1 prefix
for another revisions.

We not cache delta chain size and shortcut the computation when we see them.

Just for my mercurial-devel clone, this move the computation from about 17.5
second to about 4.8 seconds.

from typing import (
    List,
    Tuple,
)

version: int

def bdiff(a: bytes, b: bytes) -> bytes: ...
def blocks(a: bytes, b: bytes) -> List[Tuple[int, int, int, int]]: ...
def fixws(s: bytes, allws: bool) -> bytes: ...
def splitnewlines(text: bytes) -> List[bytes]: ...
def xdiffblocks(a: bytes, b: bytes) -> List[Tuple[int, int, int, int]]: ...