tests/testlib/ext-sidedata-5.py

narrow: delegate the dirstate's narrow spec writing to the transaction

This make it more transactional and will help us to simplify their backup.

The implementation is not great, but it keep the patch simple as this is not the
time for a larger refactoring yet.

# coding: utf8
# ext-sidedata-5.py - small extension to test (differently still) the sidedata
# logic
#
# Simulates a server for a simple sidedata exchange.
#
# Copyright 2021 Raphaël Gomès <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.


import hashlib
import struct

from mercurial import (
    extensions,
    revlog,
)


from mercurial.revlogutils import sidedata as sidedatamod
from mercurial.revlogutils import constants

NO_FLAGS = (0, 0)


def compute_sidedata_1(repo, revlog, rev, sidedata, text=None):
    sidedata = sidedata.copy()
    if text is None:
        text = revlog.revision(rev)
    sidedata[sidedatamod.SD_TEST1] = struct.pack('>I', len(text))
    return sidedata, NO_FLAGS


def compute_sidedata_2(repo, revlog, rev, sidedata, text=None):
    sidedata = sidedata.copy()
    if text is None:
        text = revlog.revision(rev)
    sha256 = hashlib.sha256(text).digest()
    sidedata[sidedatamod.SD_TEST2] = struct.pack('>32s', sha256)
    return sidedata, NO_FLAGS


def reposetup(ui, repo):
    # Sidedata keys happen to be the same as the categories, easier for testing.
    for kind in constants.ALL_KINDS:
        repo.register_sidedata_computer(
            kind,
            sidedatamod.SD_TEST1,
            (sidedatamod.SD_TEST1,),
            compute_sidedata_1,
            0,
        )
        repo.register_sidedata_computer(
            kind,
            sidedatamod.SD_TEST2,
            (sidedatamod.SD_TEST2,),
            compute_sidedata_2,
            0,
        )

    # We don't register sidedata computers because we don't care within these
    # tests
    repo.register_wanted_sidedata(sidedatamod.SD_TEST1)
    repo.register_wanted_sidedata(sidedatamod.SD_TEST2)


def wrapaddrevision(
    orig, self, text, transaction, link, p1, p2, *args, **kwargs
):
    if kwargs.get('sidedata') is None:
        kwargs['sidedata'] = {}
    sd = kwargs['sidedata']
    ## let's store some arbitrary data just for testing
    # text length
    sd[sidedatamod.SD_TEST1] = struct.pack('>I', len(text))
    # and sha2 hashes
    sha256 = hashlib.sha256(text).digest()
    sd[sidedatamod.SD_TEST2] = struct.pack('>32s', sha256)
    return orig(self, text, transaction, link, p1, p2, *args, **kwargs)


def extsetup(ui):
    extensions.wrapfunction(revlog.revlog, 'addrevision', wrapaddrevision)