view tests/testlib/ext-sidedata.py @ 50072:a99dcf53eebd

dirstate-guard: remove the feature

The dirstate guard duplicated some of the logic already implemented in the
transaction (and now the changing_* context).

However the feature was incomplete, for example, living only in memory meant we
could not recover from the hardest crash. In addition this duplicated with the
transaction logic meant things could go out of sync or step on each other.

Removing the feature now that we no longer needs it seems the safest.

# ext-sidedata.py - small extension to test the sidedata logic
#
# Copyright 2019 Pierre-Yves David <[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.node import nullrev
from mercurial import (
    extensions,
    requirements,
    revlog,
)

from mercurial.upgrade_utils import engine as upgrade_engine

from mercurial.revlogutils import constants
from mercurial.revlogutils import sidedata


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[sidedata.SD_TEST1] = struct.pack('>I', len(text))
    # and sha2 hashes
    sha256 = hashlib.sha256(text).digest()
    sd[sidedata.SD_TEST2] = struct.pack('>32s', sha256)
    return orig(self, text, transaction, link, p1, p2, *args, **kwargs)


def wrap_revisiondata(orig, self, nodeorrev, *args, **kwargs):
    text = orig(self, nodeorrev, *args, **kwargs)
    sd = self.sidedata(nodeorrev)
    if getattr(self, 'sidedatanocheck', False):
        return text
    if self.hassidedata:
        return text
    if nodeorrev != nullrev and nodeorrev != self.nullid:
        cat1 = sd.get(sidedata.SD_TEST1)
        if cat1 is not None and len(text) != struct.unpack('>I', cat1)[0]:
            raise RuntimeError('text size mismatch')
        expected = sd.get(sidedata.SD_TEST2)
        got = hashlib.sha256(text).digest()
        if expected is not None and got != expected:
            raise RuntimeError('sha256 mismatch')
    return text


def wrapget_sidedata_helpers(orig, srcrepo, dstrepo):
    repo, computers, removers = orig(srcrepo, dstrepo)
    assert not computers and not removers  # deal with composition later
    addedreqs = dstrepo.requirements - srcrepo.requirements

    if requirements.REVLOGV2_REQUIREMENT in addedreqs:

        def computer(repo, revlog, rev, old_sidedata):
            assert not old_sidedata  # not supported yet
            update = {}
            revlog.sidedatanocheck = True
            try:
                text = revlog.revision(rev)
            finally:
                del revlog.sidedatanocheck
            ## let's store some arbitrary data just for testing
            # text length
            update[sidedata.SD_TEST1] = struct.pack('>I', len(text))
            # and sha2 hashes
            sha256 = hashlib.sha256(text).digest()
            update[sidedata.SD_TEST2] = struct.pack('>32s', sha256)
            return update, (0, 0)

        srcrepo.register_sidedata_computer(
            constants.KIND_CHANGELOG,
            b"whatever",
            (sidedata.SD_TEST1, sidedata.SD_TEST2),
            computer,
            0,
        )
        dstrepo.register_wanted_sidedata(b"whatever")

    return sidedata.get_sidedata_helpers(srcrepo, dstrepo._wanted_sidedata)


def extsetup(ui):
    extensions.wrapfunction(revlog.revlog, 'addrevision', wrapaddrevision)
    extensions.wrapfunction(revlog.revlog, '_revisiondata', wrap_revisiondata)
    extensions.wrapfunction(
        upgrade_engine, 'get_sidedata_helpers', wrapget_sidedata_helpers
    )


def reposetup(ui, repo):
    # We don't register sidedata computers because we don't care within these
    # tests
    repo.register_wanted_sidedata(sidedata.SD_TEST1)
    repo.register_wanted_sidedata(sidedata.SD_TEST2)