view tests/testlib/ext-sidedata.py @ 48771:7dd5a2c0116a

revlog: implement changelogv2 packing and unpacking in C

This introduces a C implementation of changelogv2 records packing and unpacking
operations matching the pure Python counterpart, similarly to what we already
have for revlogv1 and revlogv2.

This is also necessary to access changelogv2 record fields from future Rust
code without going through the Python part, which would annihilate any
performance benefit.

Differential Revision: https://phab.mercurial-scm.org/D12178

# 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 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)