view tests/bruterebase.py @ 39641:aa7e312375cf

wireprotov2: let clients drive delta behavior

Previously, the "manifestdata" and "filedata" commands assumed the
receiver had all parent revisions for requested nodes. Unless the
revision had no parents, they emitted a delta instead of a fulltext.

This strategy isn't appropriate for shallow clones and for clients
that only want to access fulltext revision data for a single node
without fetching their parent revisions.

This commit adds an "haveparents" argument to the "manifestdata"
and "filedata" commands that controls delta generation behavior.

Unless "haveparents" is set, the server assumes that the client
doesn't have parent revisions unless they were previously sent
as part of the current group of revisions.

This change allows the fulltext revision data of any individual
revision to be obtained. This will facilitate shallow clones
and other data retrieval strategies that don't require all previous
revisions of an entity to be fetched.

Differential Revision: https://phab.mercurial-scm.org/D4492

# bruterebase.py - brute force rebase testing
#
# Copyright 2017 Facebook, Inc.
#
# 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

from mercurial import (
    error,
    registrar,
    revsetlang,
)

from hgext import rebase

try:
    xrange
except NameError:
    xrange = range

cmdtable = {}
command = registrar.command(cmdtable)

@command(b'debugbruterebase')
def debugbruterebase(ui, repo, source, dest):
    """for every non-empty subset of source, run rebase -r subset -d dest

    Print one line summary for each subset. Assume obsstore is enabled.
    """
    srevs = list(repo.revs(source))

    with repo.wlock(), repo.lock():
        repolen = len(repo)
        cl = repo.changelog

        def getdesc(rev):
            result = cl.changelogrevision(rev).description
            if rev >= repolen:
                result += b"'"
            return result

        for i in xrange(1, 2 ** len(srevs)):
            subset = [rev for j, rev in enumerate(srevs) if i & (1 << j) != 0]
            spec = revsetlang.formatspec(b'%ld', subset)
            tr = repo.transaction(b'rebase')
            tr.report = lambda x: 0 # hide "transaction abort"

            ui.pushbuffer()
            try:
                rebase.rebase(ui, repo, dest=dest, rev=[spec])
            except error.Abort as ex:
                summary = b'ABORT: %s' % ex
            except Exception as ex:
                summary = b'CRASH: %s' % ex
            else:
                # short summary about new nodes
                cl = repo.changelog
                descs = []
                for rev in xrange(repolen, len(repo)):
                    desc = b'%s:' % getdesc(rev)
                    for prev in cl.parentrevs(rev):
                        if prev > -1:
                            desc += getdesc(prev)
                    descs.append(desc)
                descs.sort()
                summary = b' '.join(descs)
            ui.popbuffer()
            repo.vfs.tryunlink(b'rebasestate')

            subsetdesc = b''.join(getdesc(rev) for rev in subset)
            ui.write((b'%s: %s\n') % (subsetdesc.rjust(len(srevs)), summary))
            tr.abort()