view hgext/remotefilelog/debugcommands.py @ 48390:322525db4c98

status: use filesystem time boundary to invalidate racy mtime

We record the filesystem time at the start of the status walk and use that as a
boundary to detect files that might be modified during (or right after) the
status run without the mtime allowing that edition to be detected.  We
currently do this at a second precision. In a later patch, we will use
nanosecond precision when available.

To cope with "broken" time on the file system where file could be in the
future, we also keep mtime for file over one day in the future. See inline
comment for details.

Large file tests get a bit more confused as we reduce the odds for race
condition.

As a "side effect", the win32text extension is happy again.

Differential Revision: https://phab.mercurial-scm.org/D11794

# 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,
    sha1nodeconstants,
    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 != sha1nodeconstants.nullid:
            queue.append(p1)
        if p2 != sha1nodeconstants.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 = [repo.nullid, repo.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] != repo.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 == sha1nodeconstants.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 != sha1nodeconstants.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] = sha1nodeconstants.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