view tests/testlib/ext-sidedata.py @ 46858:85e3a630cad9

revlog: move the details of revlog "v2" index inside revlog.utils.constants

the revlog module is quite large and this kind of format information would handy
for other module. So let us start to gather this information about the format in
a more appropriate place.

We update various reference to this information to use the new "source of truth"
in the process.

Differential Revision: https://phab.mercurial-scm.org/D10305

# 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.

from __future__ import absolute_import

import hashlib
import struct

from mercurial.node import (
    nullid,
    nullrev,
)
from mercurial import (
    extensions,
    requirements,
    revlog,
)

from mercurial.upgrade_utils import engine as upgrade_engine

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, sd = orig(self, nodeorrev, *args, **kwargs)
    if getattr(self, 'sidedatanocheck', False):
        return text, sd
    if self.version & 0xFFFF != 2:
        return text, sd
    if nodeorrev != nullrev and nodeorrev != 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, sd


def wrapgetsidedatacompanion(orig, srcrepo, dstrepo):
    sidedatacompanion = orig(srcrepo, dstrepo)
    addedreqs = dstrepo.requirements - srcrepo.requirements
    if requirements.SIDEDATA_REQUIREMENT in addedreqs:
        assert sidedatacompanion is None  # deal with composition later

        def sidedatacompanion(revlog, rev):
            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 False, (), update, 0, 0

    return sidedatacompanion


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


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)