comparison mercurial/copies.py @ 30360:0298a07f64d9

dirstate: change placeholder hash length to 20 bytes

Previously the new-node placeholder hash for manifests generated from the
dirstate was a 21byte long string of "!" characters. Normal hashes are only 20
bytes long.  This makes it complicated to implement more efficient manifest
implementations which rely on the hashes being fixed length.

Let's change this hash to just be 20 bytes long, and rely on the astronomical
improbability of an actual hash being 20 "!" bytes in a row (just like we rely
on no hash ever being the nullid).

A future diff will do this for added and modified dirstate markers as well, so
we're putting the new newnodeid in node.py so there's a common place for these
placeholders.

30359:673f0fdc1046

        if rev is None:
            revs = [p.rev() for p in ctx.parents()]
        ac = repo.changelog.ancestors(revs, inclusive=True)
        ctx._ancestrycontext = ac
    def makectx(f, n):
        if len(n) != 20:  # in a working context?
            if ctx.rev() is None:
                return ctx.filectx(f)
            return repo[None][f]
        fctx = repo.filectx(f, fileid=n)
        # setup only needed for filectx not create from a changectx

30360:0298a07f64d9

        if rev is None:
            revs = [p.rev() for p in ctx.parents()]
        ac = repo.changelog.ancestors(revs, inclusive=True)
        ctx._ancestrycontext = ac
    def makectx(f, n):
        if len(n) != 20 or n in node.wdirnodes:  # in a working context?
            if ctx.rev() is None:
                return ctx.filectx(f)
            return repo[None][f]
        fctx = repo.filectx(f, fileid=n)
        # setup only needed for filectx not create from a changectx