hgext/remotefilelog/debugcommands.py

rebase: skip obsolete commits even if they have pruned successors

Issue 5782 reported that `hg rebase -r <obsolete commit with pruned
successor>` failed with an error saying that it would cause
divergence. Commit b7e2cf114e85 (rebase: do not consider extincts for
divergence detection (issue5782), 2018-02-09) fixed it by letting you
rebase the commit. However, that fix seems inconsistent with how we
handle `hg rebase -r <pruned commit>`. To me, it should make no
difference whether a commit is pruned itself or if it has (only)
pruned successors. This patch changes it so we treat these two kinds
of commits the same way. I let the message we print remain "note: not
rebasing <commit>, it has no successor" even though that last part is
not technically correct for commits with pruned successors. I doubt it
will confuse users.

Differential Revision: https://phab.mercurial-scm.org/D10240

# debugcommands.py - debug logic for remotefilelog
#
# Copyright 2013 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

import os
import zlib

from mercurial.node import (
    bin,
    hex,
    nullid,
    short,
)
from mercurial.i18n import _
from mercurial.pycompat import open
from mercurial import (
    error,
    filelog,
    lock as lockmod,
    pycompat,
    revlog,
)
from mercurial.utils import hashutil
from . import (
    constants,
    datapack,
    fileserverclient,
    historypack,
    repack,
    shallowutil,
)


def debugremotefilelog(ui, path, **opts):
    decompress = opts.get('decompress')

    size, firstnode, mapping = parsefileblob(path, decompress)

    ui.status(_(b"size: %d bytes\n") % size)
    ui.status(_(b"path: %s \n") % path)
    ui.status(_(b"key: %s \n") % (short(firstnode)))
    ui.status(_(b"\n"))
    ui.status(
        _(b"%12s => %12s %13s %13s %12s\n")
        % (b"node", b"p1", b"p2", b"linknode", b"copyfrom")
    )

    queue = [firstnode]
    while queue:
        node = queue.pop(0)
        p1, p2, linknode, copyfrom = mapping[node]
        ui.status(
            _(b"%s => %s  %s  %s  %s\n")
            % (short(node), short(p1), short(p2), short(linknode), copyfrom)
        )
        if p1 != nullid:
            queue.append(p1)
        if p2 != nullid:
            queue.append(p2)


def buildtemprevlog(repo, file):
    # get filename key
    filekey = hex(hashutil.sha1(file).digest())
    filedir = os.path.join(repo.path, b'store/data', filekey)

    # sort all entries based on linkrev
    fctxs = []
    for filenode in os.listdir(filedir):
        if b'_old' not in filenode:
            fctxs.append(repo.filectx(file, fileid=bin(filenode)))

    fctxs = sorted(fctxs, key=lambda x: x.linkrev())

    # add to revlog
    temppath = repo.sjoin(b'data/temprevlog.i')
    if os.path.exists(temppath):
        os.remove(temppath)
    r = filelog.filelog(repo.svfs, b'temprevlog')

    class faket(object):
        def add(self, a, b, c):
            pass

    t = faket()
    for fctx in fctxs:
        if fctx.node() not in repo:
            continue

        p = fctx.filelog().parents(fctx.filenode())
        meta = {}
        if fctx.renamed():
            meta[b'copy'] = fctx.renamed()[0]
            meta[b'copyrev'] = hex(fctx.renamed()[1])

        r.add(fctx.data(), meta, t, fctx.linkrev(), p[0], p[1])

    return r


def debugindex(orig, ui, repo, file_=None, **opts):
    """dump the contents of an index file"""
    if (
        opts.get('changelog')
        or opts.get('manifest')
        or opts.get('dir')
        or not shallowutil.isenabled(repo)
        or not repo.shallowmatch(file_)
    ):
        return orig(ui, repo, file_, **opts)

    r = buildtemprevlog(repo, file_)

    # debugindex like normal
    format = opts.get(b'format', 0)
    if format not in (0, 1):
        raise error.Abort(_(b"unknown format %d") % format)

    generaldelta = r.version & revlog.FLAG_GENERALDELTA
    if generaldelta:
        basehdr = b' delta'
    else:
        basehdr = b'  base'

    if format == 0:
        ui.write(
            (
                b"   rev    offset  length " + basehdr + b" linkrev"
                b" nodeid       p1           p2\n"
            )
        )
    elif format == 1:
        ui.write(
            (
                b"   rev flag   offset   length"
                b"     size " + basehdr + b"   link     p1     p2"
                b"       nodeid\n"
            )
        )

    for i in r:
        node = r.node(i)
        if generaldelta:
            base = r.deltaparent(i)
        else:
            base = r.chainbase(i)
        if format == 0:
            try:
                pp = r.parents(node)
            except Exception:
                pp = [nullid, nullid]
            ui.write(
                b"% 6d % 9d % 7d % 6d % 7d %s %s %s\n"
                % (
                    i,
                    r.start(i),
                    r.length(i),
                    base,
                    r.linkrev(i),
                    short(node),
                    short(pp[0]),
                    short(pp[1]),
                )
            )
        elif format == 1:
            pr = r.parentrevs(i)
            ui.write(
                b"% 6d %04x % 8d % 8d % 8d % 6d % 6d % 6d % 6d %s\n"
                % (
                    i,
                    r.flags(i),
                    r.start(i),
                    r.length(i),
                    r.rawsize(i),
                    base,
                    r.linkrev(i),
                    pr[0],
                    pr[1],
                    short(node),
                )
            )


def debugindexdot(orig, ui, repo, file_):
    """dump an index DAG as a graphviz dot file"""
    if not shallowutil.isenabled(repo):
        return orig(ui, repo, file_)

    r = buildtemprevlog(repo, os.path.basename(file_)[:-2])

    ui.writenoi18n(b"digraph G {\n")
    for i in r:
        node = r.node(i)
        pp = r.parents(node)
        ui.write(b"\t%d -> %d\n" % (r.rev(pp[0]), i))
        if pp[1] != nullid:
            ui.write(b"\t%d -> %d\n" % (r.rev(pp[1]), i))
    ui.write(b"}\n")


def verifyremotefilelog(ui, path, **opts):
    decompress = opts.get('decompress')

    for root, dirs, files in os.walk(path):
        for file in files:
            if file == b"repos":
                continue
            filepath = os.path.join(root, file)
            size, firstnode, mapping = parsefileblob(filepath, decompress)
            for p1, p2, linknode, copyfrom in pycompat.itervalues(mapping):
                if linknode == nullid:
                    actualpath = os.path.relpath(root, path)
                    key = fileserverclient.getcachekey(
                        b"reponame", actualpath, file
                    )
                    ui.status(
                        b"%s %s\n" % (key, os.path.relpath(filepath, path))
                    )


def _decompressblob(raw):
    return zlib.decompress(raw)


def parsefileblob(path, decompress):
    f = open(path, b"rb")
    try:
        raw = f.read()
    finally:
        f.close()

    if decompress:
        raw = _decompressblob(raw)

    offset, size, flags = shallowutil.parsesizeflags(raw)
    start = offset + size

    firstnode = None

    mapping = {}
    while start < len(raw):
        divider = raw.index(b'\0', start + 80)

        currentnode = raw[start : (start + 20)]
        if not firstnode:
            firstnode = currentnode

        p1 = raw[(start + 20) : (start + 40)]
        p2 = raw[(start + 40) : (start + 60)]
        linknode = raw[(start + 60) : (start + 80)]
        copyfrom = raw[(start + 80) : divider]

        mapping[currentnode] = (p1, p2, linknode, copyfrom)
        start = divider + 1

    return size, firstnode, mapping


def debugdatapack(ui, *paths, **opts):
    for path in paths:
        if b'.data' in path:
            path = path[: path.index(b'.data')]
        ui.write(b"%s:\n" % path)
        dpack = datapack.datapack(path)
        node = opts.get('node')
        if node:
            deltachain = dpack.getdeltachain(b'', bin(node))
            dumpdeltachain(ui, deltachain, **opts)
            return

        if opts.get('long'):
            hashformatter = hex
            hashlen = 42
        else:
            hashformatter = short
            hashlen = 14

        lastfilename = None
        totaldeltasize = 0
        totalblobsize = 0

        def printtotals():
            if lastfilename is not None:
                ui.write(b"\n")
            if not totaldeltasize or not totalblobsize:
                return
            difference = totalblobsize - totaldeltasize
            deltastr = b"%0.1f%% %s" % (
                (100.0 * abs(difference) / totalblobsize),
                (b"smaller" if difference > 0 else b"bigger"),
            )

            ui.writenoi18n(
                b"Total:%s%s  %s (%s)\n"
                % (
                    b"".ljust(2 * hashlen - len(b"Total:")),
                    (b'%d' % totaldeltasize).ljust(12),
                    (b'%d' % totalblobsize).ljust(9),
                    deltastr,
                )
            )

        bases = {}
        nodes = set()
        failures = 0
        for filename, node, deltabase, deltalen in dpack.iterentries():
            bases[node] = deltabase
            if node in nodes:
                ui.write((b"Bad entry: %s appears twice\n" % short(node)))
                failures += 1
            nodes.add(node)
            if filename != lastfilename:
                printtotals()
                name = b'(empty name)' if filename == b'' else filename
                ui.write(b"%s:\n" % name)
                ui.write(
                    b"%s%s%s%s\n"
                    % (
                        b"Node".ljust(hashlen),
                        b"Delta Base".ljust(hashlen),
                        b"Delta Length".ljust(14),
                        b"Blob Size".ljust(9),
                    )
                )
                lastfilename = filename
                totalblobsize = 0
                totaldeltasize = 0

            # Metadata could be missing, in which case it will be an empty dict.
            meta = dpack.getmeta(filename, node)
            if constants.METAKEYSIZE in meta:
                blobsize = meta[constants.METAKEYSIZE]
                totaldeltasize += deltalen
                totalblobsize += blobsize
            else:
                blobsize = b"(missing)"
            ui.write(
                b"%s  %s  %s%s\n"
                % (
                    hashformatter(node),
                    hashformatter(deltabase),
                    (b'%d' % deltalen).ljust(14),
                    pycompat.bytestr(blobsize),
                )
            )

        if filename is not None:
            printtotals()

        failures += _sanitycheck(ui, set(nodes), bases)
        if failures > 1:
            ui.warn((b"%d failures\n" % failures))
            return 1


def _sanitycheck(ui, nodes, bases):
    """
    Does some basic sanity checking on a packfiles with ``nodes`` ``bases`` (a
    mapping of node->base):

    - Each deltabase must itself be a node elsewhere in the pack
    - There must be no cycles
    """
    failures = 0
    for node in nodes:
        seen = set()
        current = node
        deltabase = bases[current]

        while deltabase != nullid:
            if deltabase not in nodes:
                ui.warn(
                    (
                        b"Bad entry: %s has an unknown deltabase (%s)\n"
                        % (short(node), short(deltabase))
                    )
                )
                failures += 1
                break

            if deltabase in seen:
                ui.warn(
                    (
                        b"Bad entry: %s has a cycle (at %s)\n"
                        % (short(node), short(deltabase))
                    )
                )
                failures += 1
                break

            current = deltabase
            seen.add(current)
            deltabase = bases[current]
        # Since ``node`` begins a valid chain, reset/memoize its base to nullid
        # so we don't traverse it again.
        bases[node] = nullid
    return failures


def dumpdeltachain(ui, deltachain, **opts):
    hashformatter = hex
    hashlen = 40

    lastfilename = None
    for filename, node, filename, deltabasenode, delta in deltachain:
        if filename != lastfilename:
            ui.write(b"\n%s\n" % filename)
            lastfilename = filename
        ui.write(
            b"%s  %s  %s  %s\n"
            % (
                b"Node".ljust(hashlen),
                b"Delta Base".ljust(hashlen),
                b"Delta SHA1".ljust(hashlen),
                b"Delta Length".ljust(6),
            )
        )

        ui.write(
            b"%s  %s  %s  %d\n"
            % (
                hashformatter(node),
                hashformatter(deltabasenode),
                hex(hashutil.sha1(delta).digest()),
                len(delta),
            )
        )


def debughistorypack(ui, path):
    if b'.hist' in path:
        path = path[: path.index(b'.hist')]
    hpack = historypack.historypack(path)

    lastfilename = None
    for entry in hpack.iterentries():
        filename, node, p1node, p2node, linknode, copyfrom = entry
        if filename != lastfilename:
            ui.write(b"\n%s\n" % filename)
            ui.write(
                b"%s%s%s%s%s\n"
                % (
                    b"Node".ljust(14),
                    b"P1 Node".ljust(14),
                    b"P2 Node".ljust(14),
                    b"Link Node".ljust(14),
                    b"Copy From",
                )
            )
            lastfilename = filename
        ui.write(
            b"%s  %s  %s  %s  %s\n"
            % (
                short(node),
                short(p1node),
                short(p2node),
                short(linknode),
                copyfrom,
            )
        )


def debugwaitonrepack(repo):
    with lockmod.lock(repack.repacklockvfs(repo), b"repacklock", timeout=-1):
        return


def debugwaitonprefetch(repo):
    with repo._lock(
        repo.svfs,
        b"prefetchlock",
        True,
        None,
        None,
        _(b'prefetching in %s') % repo.origroot,
    ):
        pass