annotate hgext/largefiles/overrides.py @ 15916:c96148346af8

largefiles: cache new largefiles for new heads when pulling

When the user pulls from a remote repository that is not his default repo, it
is quite likely that he will pull a new head.  This means that if he tries to
merge or rebase with the other head, he will run into a problem becuase
largefiles has no way of tracking where the remote repository for this other
head is, so it cannot download the largefiles from this other remote repository.
It will attempt to download them from its default remote repository, which will
not yet contain the largefiles.

This patch solves this problem by caching any new largefiles for all heads
directly into the system cache at the time of the pull, so they are available
later.

This behavior is actually more in line with Mercurial's distributed nature,
because pulling already implies we have a connection to the remote server, but
merging or rebasing does not.

# Copyright 2009-2010 Gregory P. Ward
# Copyright 2009-2010 Intelerad Medical Systems Incorporated
# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''Overridden Mercurial commands and functions for the largefiles extension'''

import os
import copy

from mercurial import hg, commands, util, cmdutil, scmutil, match as match_, \
    node, archival, error, merge
from mercurial.i18n import _
from mercurial.node import hex
from hgext import rebase

import lfutil
import lfcommands

# -- Utility functions: commonly/repeatedly needed functionality ---------------

def installnormalfilesmatchfn(manifest):
    '''overrides scmutil.match so that the matcher it returns will ignore all
    largefiles'''
    oldmatch = None # for the closure
    def override_match(ctx, pats=[], opts={}, globbed=False,
            default='relpath'):
        match = oldmatch(ctx, pats, opts, globbed, default)
        m = copy.copy(match)
        notlfile = lambda f: not (lfutil.isstandin(f) or lfutil.standin(f) in
                manifest)
        m._files = filter(notlfile, m._files)
        m._fmap = set(m._files)
        orig_matchfn = m.matchfn
        m.matchfn = lambda f: notlfile(f) and orig_matchfn(f) or None
        return m
    oldmatch = installmatchfn(override_match)

def installmatchfn(f):
    oldmatch = scmutil.match
    setattr(f, 'oldmatch', oldmatch)
    scmutil.match = f
    return oldmatch

def restorematchfn():
    '''restores scmutil.match to what it was before installnormalfilesmatchfn
    was called.  no-op if scmutil.match is its original function.

    Note that n calls to installnormalfilesmatchfn will require n calls to
    restore matchfn to reverse'''
    scmutil.match = getattr(scmutil.match, 'oldmatch', scmutil.match)

def add_largefiles(ui, repo, *pats, **opts):
    large = opts.pop('large', None)
    lfsize = lfutil.getminsize(
        ui, lfutil.islfilesrepo(repo), opts.pop('lfsize', None))

    lfmatcher = None
    if lfutil.islfilesrepo(repo):
        lfpats = ui.configlist(lfutil.longname, 'patterns', default=[])
        if lfpats:
            lfmatcher = match_.match(repo.root, '', list(lfpats))

    lfnames = []
    m = scmutil.match(repo[None], pats, opts)
    m.bad = lambda x, y: None
    wctx = repo[None]
    for f in repo.walk(m):
        exact = m.exact(f)
        lfile = lfutil.standin(f) in wctx
        nfile = f in wctx
        exists = lfile or nfile

        # Don't warn the user when they attempt to add a normal tracked file.
        # The normal add code will do that for us.
        if exact and exists:
            if lfile:
                ui.warn(_('%s already a largefile\n') % f)
            continue

        if exact or not exists:
            abovemin = (lfsize and
                        os.lstat(repo.wjoin(f)).st_size >= lfsize * 1024 * 1024)
            if large or abovemin or (lfmatcher and lfmatcher(f)):
                lfnames.append(f)
                if ui.verbose or not exact:
                    ui.status(_('adding %s as a largefile\n') % m.rel(f))

    bad = []
    standins = []

    # Need to lock, otherwise there could be a race condition between
    # when standins are created and added to the repo.
    wlock = repo.wlock()
    try:
        if not opts.get('dry_run'):
            lfdirstate = lfutil.openlfdirstate(ui, repo)
            for f in lfnames:
                standinname = lfutil.standin(f)
                lfutil.writestandin(repo, standinname, hash='',
                    executable=lfutil.getexecutable(repo.wjoin(f)))
                standins.append(standinname)
                if lfdirstate[f] == 'r':
                    lfdirstate.normallookup(f)
                else:
                    lfdirstate.add(f)
            lfdirstate.write()
            bad += [lfutil.splitstandin(f)
                    for f in lfutil.repo_add(repo, standins)
                    if f in m.files()]
    finally:
        wlock.release()
    return bad

def remove_largefiles(ui, repo, *pats, **opts):
    after = opts.get('after')
    if not pats and not after:
        raise util.Abort(_('no files specified'))
    m = scmutil.match(repo[None], pats, opts)
    try:
        repo.lfstatus = True
        s = repo.status(match=m, clean=True)
    finally:
        repo.lfstatus = False
    manifest = repo[None].manifest()
    modified, added, deleted, clean = [[f for f in list
                                        if lfutil.standin(f) in manifest]
                                       for list in [s[0], s[1], s[3], s[6]]]

    def warn(files, reason):
        for f in files:
            ui.warn(_('not removing %s: %s (use forget to undo)\n')
                    % (m.rel(f), reason))

    if after:
        remove, forget = deleted, []
        warn(modified + added + clean, _('file still exists'))
    else:
        remove, forget = deleted + clean, []
        warn(modified, _('file is modified'))
        warn(added, _('file has been marked for add'))

    for f in sorted(remove + forget):
        if ui.verbose or not m.exact(f):
            ui.status(_('removing %s\n') % m.rel(f))

    # Need to lock because standin files are deleted then removed from the
    # repository and we could race inbetween.
    wlock = repo.wlock()
    try:
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        for f in remove:
            if not after:
                # If this is being called by addremove, notify the user that we
                # are removing the file.
                if getattr(repo, "_isaddremove", False):
                    ui.status(_('removing %s\n' % f))
                if os.path.exists(repo.wjoin(f)):
                    os.unlink(repo.wjoin(f))
                currentdir = os.path.split(f)[0]
                while currentdir and not os.listdir(repo.wjoin(currentdir)):
                    os.rmdir(repo.wjoin(currentdir))
                    currentdir = os.path.split(currentdir)[0]
            lfdirstate.remove(f)
        lfdirstate.write()
        forget = [lfutil.standin(f) for f in forget]
        remove = [lfutil.standin(f) for f in remove]
        lfutil.repo_forget(repo, forget)
        # If this is being called by addremove, let the original addremove
        # function handle this.
        if not getattr(repo, "_isaddremove", False):
            lfutil.repo_remove(repo, remove, unlink=True)
    finally:
        wlock.release()

# -- Wrappers: modify existing commands --------------------------------

# Add works by going through the files that the user wanted to add and
# checking if they should be added as largefiles. Then it makes a new
# matcher which matches only the normal files and runs the original
# version of add.
def override_add(orig, ui, repo, *pats, **opts):
    bad = add_largefiles(ui, repo, *pats, **opts)
    installnormalfilesmatchfn(repo[None].manifest())
    result = orig(ui, repo, *pats, **opts)
    restorematchfn()

    return (result == 1 or bad) and 1 or 0

def override_remove(orig, ui, repo, *pats, **opts):
    installnormalfilesmatchfn(repo[None].manifest())
    orig(ui, repo, *pats, **opts)
    restorematchfn()
    remove_largefiles(ui, repo, *pats, **opts)

def override_status(orig, ui, repo, *pats, **opts):
    try:
        repo.lfstatus = True
        return orig(ui, repo, *pats, **opts)
    finally:
        repo.lfstatus = False

def override_log(orig, ui, repo, *pats, **opts):
    try:
        repo.lfstatus = True
        orig(ui, repo, *pats, **opts)
    finally:
        repo.lfstatus = False

def override_verify(orig, ui, repo, *pats, **opts):
    large = opts.pop('large', False)
    all = opts.pop('lfa', False)
    contents = opts.pop('lfc', False)

    result = orig(ui, repo, *pats, **opts)
    if large:
        result = result or lfcommands.verifylfiles(ui, repo, all, contents)
    return result

# Override needs to refresh standins so that update's normal merge
# will go through properly. Then the other update hook (overriding repo.update)
# will get the new files. Filemerge is also overriden so that the merge
# will merge standins correctly.
def override_update(orig, ui, repo, *pats, **opts):
    lfdirstate = lfutil.openlfdirstate(ui, repo)
    s = lfdirstate.status(match_.always(repo.root, repo.getcwd()), [], False,
        False, False)
    (unsure, modified, added, removed, missing, unknown, ignored, clean) = s

    # Need to lock between the standins getting updated and their
    # largefiles getting updated
    wlock = repo.wlock()
    try:
        if opts['check']:
            mod = len(modified) > 0
            for lfile in unsure:
                standin = lfutil.standin(lfile)
                if repo['.'][standin].data().strip() != \
                        lfutil.hashfile(repo.wjoin(lfile)):
                    mod = True
                else:
                    lfdirstate.normal(lfile)
            lfdirstate.write()
            if mod:
                raise util.Abort(_('uncommitted local changes'))
        # XXX handle removed differently
        if not opts['clean']:
            for lfile in unsure + modified + added:
                lfutil.updatestandin(repo, lfutil.standin(lfile))
    finally:
        wlock.release()
    return orig(ui, repo, *pats, **opts)

# Before starting the manifest merge, merge.updates will call
# _checkunknown to check if there are any files in the merged-in
# changeset that collide with unknown files in the working copy.
#
# The largefiles are seen as unknown, so this prevents us from merging
# in a file 'foo' if we already have a largefile with the same name.
#
# The overridden function filters the unknown files by removing any
# largefiles. This makes the merge proceed and we can then handle this
# case further in the overridden manifestmerge function below.
def override_checkunknown(origfn, wctx, mctx, folding):
    origunknown = wctx.unknown()
    wctx._unknown = filter(lambda f: lfutil.standin(f) not in wctx, origunknown)
    try:
        return origfn(wctx, mctx, folding)
    finally:
        wctx._unknown = origunknown

# The manifest merge handles conflicts on the manifest level. We want
# to handle changes in largefile-ness of files at this level too.
#
# The strategy is to run the original manifestmerge and then process
# the action list it outputs. There are two cases we need to deal with:
#
# 1. Normal file in p1, largefile in p2. Here the largefile is
#    detected via its standin file, which will enter the working copy
#    with a "get" action. It is not "merge" since the standin is all
#    Mercurial is concerned with at this level -- the link to the
#    existing normal file is not relevant here.
#
# 2. Largefile in p1, normal file in p2. Here we get a "merge" action
#    since the largefile will be present in the working copy and
#    different from the normal file in p2. Mercurial therefore
#    triggers a merge action.
#
# In both cases, we prompt the user and emit new actions to either
# remove the standin (if the normal file was kept) or to remove the
# normal file and get the standin (if the largefile was kept). The
# default prompt answer is to use the largefile version since it was
# presumably changed on purpose.
#
# Finally, the merge.applyupdates function will then take care of
# writing the files into the working copy and lfcommands.updatelfiles
# will update the largefiles.
def override_manifestmerge(origfn, repo, p1, p2, pa, overwrite, partial):
    actions = origfn(repo, p1, p2, pa, overwrite, partial)
    processed = []

    for action in actions:
        if overwrite:
            processed.append(action)
            continue
        f, m = action[:2]

        choices = (_('&Largefile'), _('&Normal file'))
        if m == "g" and lfutil.splitstandin(f) in p1 and f in p2:
            # Case 1: normal file in the working copy, largefile in
            # the second parent
            lfile = lfutil.splitstandin(f)
            standin = f
            msg = _('%s has been turned into a largefile\n'
                    'use (l)argefile or keep as (n)ormal file?') % lfile
            if repo.ui.promptchoice(msg, choices, 0) == 0:
                processed.append((lfile, "r"))
                processed.append((standin, "g", p2.flags(standin)))
            else:
                processed.append((standin, "r"))
        elif m == "m" and lfutil.standin(f) in p1 and f in p2:
            # Case 2: largefile in the working copy, normal file in
            # the second parent
            standin = lfutil.standin(f)
            lfile = f
            msg = _('%s has been turned into a normal file\n'
                    'keep as (l)argefile or use (n)ormal file?') % lfile
            if repo.ui.promptchoice(msg, choices, 0) == 0:
                processed.append((lfile, "r"))
            else:
                processed.append((standin, "r"))
                processed.append((lfile, "g", p2.flags(lfile)))
        else:
            processed.append(action)

    return processed

# Override filemerge to prompt the user about how they wish to merge
# largefiles. This will handle identical edits, and copy/rename +
# edit without prompting the user.
def override_filemerge(origfn, repo, mynode, orig, fcd, fco, fca):
    # Use better variable names here. Because this is a wrapper we cannot
    # change the variable names in the function declaration.
    fcdest, fcother, fcancestor = fcd, fco, fca
    if not lfutil.isstandin(orig):
        return origfn(repo, mynode, orig, fcdest, fcother, fcancestor)
    else:
        if not fcother.cmp(fcdest): # files identical?
            return None

        # backwards, use working dir parent as ancestor
        if fcancestor == fcother:
            fcancestor = fcdest.parents()[0]

        if orig != fcother.path():
            repo.ui.status(_('merging %s and %s to %s\n')
                           % (lfutil.splitstandin(orig),
                              lfutil.splitstandin(fcother.path()),
                              lfutil.splitstandin(fcdest.path())))
        else:
            repo.ui.status(_('merging %s\n')
                           % lfutil.splitstandin(fcdest.path()))

        if fcancestor.path() != fcother.path() and fcother.data() == \
                fcancestor.data():
            return 0
        if fcancestor.path() != fcdest.path() and fcdest.data() == \
                fcancestor.data():
            repo.wwrite(fcdest.path(), fcother.data(), fcother.flags())
            return 0

        if repo.ui.promptchoice(_('largefile %s has a merge conflict\n'
                             'keep (l)ocal or take (o)ther?') %
                             lfutil.splitstandin(orig),
                             (_('&Local'), _('&Other')), 0) == 0:
            return 0
        else:
            repo.wwrite(fcdest.path(), fcother.data(), fcother.flags())
            return 0

# Copy first changes the matchers to match standins instead of
# largefiles.  Then it overrides util.copyfile in that function it
# checks if the destination largefile already exists. It also keeps a
# list of copied files so that the largefiles can be copied and the
# dirstate updated.
def override_copy(orig, ui, repo, pats, opts, rename=False):
    # doesn't remove largefile on rename
    if len(pats) < 2:
        # this isn't legal, let the original function deal with it
        return orig(ui, repo, pats, opts, rename)

    def makestandin(relpath):
        path = scmutil.canonpath(repo.root, repo.getcwd(), relpath)
        return os.path.join(repo.wjoin(lfutil.standin(path)))

    fullpats = scmutil.expandpats(pats)
    dest = fullpats[-1]

    if os.path.isdir(dest):
        if not os.path.isdir(makestandin(dest)):
            os.makedirs(makestandin(dest))
    # This could copy both lfiles and normal files in one command,
    # but we don't want to do that. First replace their matcher to
    # only match normal files and run it, then replace it to just
    # match largefiles and run it again.
    nonormalfiles = False
    nolfiles = False
    try:
        try:
            installnormalfilesmatchfn(repo[None].manifest())
            result = orig(ui, repo, pats, opts, rename)
        except util.Abort, e:
            if str(e) != 'no files to copy':
                raise e
            else:
                nonormalfiles = True
            result = 0
    finally:
        restorematchfn()

    # The first rename can cause our current working directory to be removed.
    # In that case there is nothing left to copy/rename so just quit.
    try:
        repo.getcwd()
    except OSError:
        return result

    try:
        try:
            # When we call orig below it creates the standins but we don't add them
            # to the dir state until later so lock during that time.
            wlock = repo.wlock()

            manifest = repo[None].manifest()
            oldmatch = None # for the closure
            def override_match(ctx, pats=[], opts={}, globbed=False,
                    default='relpath'):
                newpats = []
                # The patterns were previously mangled to add the standin
                # directory; we need to remove that now
                for pat in pats:
                    if match_.patkind(pat) is None and lfutil.shortname in pat:
                        newpats.append(pat.replace(lfutil.shortname, ''))
                    else:
                        newpats.append(pat)
                match = oldmatch(ctx, newpats, opts, globbed, default)
                m = copy.copy(match)
                lfile = lambda f: lfutil.standin(f) in manifest
                m._files = [lfutil.standin(f) for f in m._files if lfile(f)]
                m._fmap = set(m._files)
                orig_matchfn = m.matchfn
                m.matchfn = lambda f: (lfutil.isstandin(f) and
                                    lfile(lfutil.splitstandin(f)) and
                                    orig_matchfn(lfutil.splitstandin(f)) or
                                    None)
                return m
            oldmatch = installmatchfn(override_match)
            listpats = []
            for pat in pats:
                if match_.patkind(pat) is not None:
                    listpats.append(pat)
                else:
                    listpats.append(makestandin(pat))

            try:
                origcopyfile = util.copyfile
                copiedfiles = []
                def override_copyfile(src, dest):
                    if (lfutil.shortname in src and
                        dest.startswith(repo.wjoin(lfutil.shortname))):
                        destlfile = dest.replace(lfutil.shortname, '')
                        if not opts['force'] and os.path.exists(destlfile):
                            raise IOError('',
                                _('destination largefile already exists'))
                    copiedfiles.append((src, dest))
                    origcopyfile(src, dest)

                util.copyfile = override_copyfile
                result += orig(ui, repo, listpats, opts, rename)
            finally:
                util.copyfile = origcopyfile

            lfdirstate = lfutil.openlfdirstate(ui, repo)
            for (src, dest) in copiedfiles:
                if (lfutil.shortname in src and
                    dest.startswith(repo.wjoin(lfutil.shortname))):
                    srclfile = src.replace(repo.wjoin(lfutil.standin('')), '')
                    destlfile = dest.replace(repo.wjoin(lfutil.standin('')), '')
                    destlfiledir = os.path.dirname(destlfile) or '.'
                    if not os.path.isdir(destlfiledir):
                        os.makedirs(destlfiledir)
                    if rename:
                        os.rename(repo.wjoin(srclfile), repo.wjoin(destlfile))
                        lfdirstate.remove(srclfile)
                    else:
                        util.copyfile(srclfile, destlfile)
                    lfdirstate.add(destlfile)
            lfdirstate.write()
        except util.Abort, e:
            if str(e) != 'no files to copy':
                raise e
            else:
                nolfiles = True
    finally:
        restorematchfn()
        wlock.release()

    if nolfiles and nonormalfiles:
        raise util.Abort(_('no files to copy'))

    return result

# When the user calls revert, we have to be careful to not revert any
# changes to other largefiles accidentally. This means we have to keep
# track of the largefiles that are being reverted so we only pull down
# the necessary largefiles.
#
# Standins are only updated (to match the hash of largefiles) before
# commits. Update the standins then run the original revert, changing
# the matcher to hit standins instead of largefiles. Based on the
# resulting standins update the largefiles. Then return the standins
# to their proper state
def override_revert(orig, ui, repo, *pats, **opts):
    # Because we put the standins in a bad state (by updating them)
    # and then return them to a correct state we need to lock to
    # prevent others from changing them in their incorrect state.
    wlock = repo.wlock()
    try:
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        (modified, added, removed, missing, unknown, ignored, clean) = \
            lfutil.lfdirstate_status(lfdirstate, repo, repo['.'].rev())
        for lfile in modified:
            lfutil.updatestandin(repo, lfutil.standin(lfile))

        try:
            ctx = repo[opts.get('rev')]
            oldmatch = None # for the closure
            def override_match(ctx, pats=[], opts={}, globbed=False,
                    default='relpath'):
                match = oldmatch(ctx, pats, opts, globbed, default)
                m = copy.copy(match)
                def tostandin(f):
                    if lfutil.standin(f) in ctx or lfutil.standin(f) in ctx:
                        return lfutil.standin(f)
                    elif lfutil.standin(f) in repo[None]:
                        return None
                    return f
                m._files = [tostandin(f) for f in m._files]
                m._files = [f for f in m._files if f is not None]
                m._fmap = set(m._files)
                orig_matchfn = m.matchfn
                def matchfn(f):
                    if lfutil.isstandin(f):
                        # We need to keep track of what largefiles are being
                        # matched so we know which ones to update later --
                        # otherwise we accidentally revert changes to other
                        # largefiles. This is repo-specific, so duckpunch the
                        # repo object to keep the list of largefiles for us
                        # later.
                        if orig_matchfn(lfutil.splitstandin(f)) and \
                                (f in repo[None] or f in ctx):
                            lfileslist = getattr(repo, '_lfilestoupdate', [])
                            lfileslist.append(lfutil.splitstandin(f))
                            repo._lfilestoupdate = lfileslist
                            return True
                        else:
                            return False
                    return orig_matchfn(f)
                m.matchfn = matchfn
                return m
            oldmatch = installmatchfn(override_match)
            scmutil.match
            matches = override_match(repo[None], pats, opts)
            orig(ui, repo, *pats, **opts)
        finally:
            restorematchfn()
        lfileslist = getattr(repo, '_lfilestoupdate', [])
        lfcommands.updatelfiles(ui, repo, filelist=lfileslist,
                                printmessage=False)

        # empty out the largefiles list so we start fresh next time
        repo._lfilestoupdate = []
        for lfile in modified:
            if lfile in lfileslist:
                if os.path.exists(repo.wjoin(lfutil.standin(lfile))) and lfile\
                        in repo['.']:
                    lfutil.writestandin(repo, lfutil.standin(lfile),
                        repo['.'][lfile].data().strip(),
                        'x' in repo['.'][lfile].flags())
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        for lfile in added:
            standin = lfutil.standin(lfile)
            if standin not in ctx and (standin in matches or opts.get('all')):
                if lfile in lfdirstate:
                    lfdirstate.drop(lfile)
                util.unlinkpath(repo.wjoin(standin))
        lfdirstate.write()
    finally:
        wlock.release()

def hg_update(orig, repo, node):
    result = orig(repo, node)
    lfcommands.updatelfiles(repo.ui, repo)
    return result

def hg_clean(orig, repo, node, show_stats=True):
    result = orig(repo, node, show_stats)
    lfcommands.updatelfiles(repo.ui, repo)
    return result

def hg_merge(orig, repo, node, force=None, remind=True):
    # Mark the repo as being in the middle of a merge, so that
    # updatelfiles() will know that it needs to trust the standins in
    # the working copy, not in the standins in the current node
    repo._ismerging = True
    try:
        result = orig(repo, node, force, remind)
        lfcommands.updatelfiles(repo.ui, repo)
    finally:
        repo._ismerging = False
    return result

# When we rebase a repository with remotely changed largefiles, we need to
# take some extra care so that the largefiles are correctly updated in the
# working copy
def override_pull(orig, ui, repo, source=None, **opts):
    if opts.get('rebase', False):
        repo._isrebasing = True
        try:
            if opts.get('update'):
                 del opts['update']
                 ui.debug('--update and --rebase are not compatible, ignoring '
                          'the update flag\n')
            del opts['rebase']
            cmdutil.bailifchanged(repo)
            revsprepull = len(repo)
            origpostincoming = commands.postincoming
            def _dummy(*args, **kwargs):
                pass
            commands.postincoming = _dummy
            repo.lfpullsource = source
            if not source:
                source = 'default'
            try:
                result = commands.pull(ui, repo, source, **opts)
            finally:
                commands.postincoming = origpostincoming
            revspostpull = len(repo)
            if revspostpull > revsprepull:
                result = result or rebase.rebase(ui, repo)
        finally:
            repo._isrebasing = False
    else:
        repo.lfpullsource = source
        if not source:
            source = 'default'
        result = orig(ui, repo, source, **opts)
        # If we do not have the new largefiles for any new heads we pulled, we
        # will run into a problem later if we try to merge or rebase with one of
        # these heads, so cache the largefiles now direclty into the system
        # cache.
        ui.status(_("caching new largefiles\n"))
        numcached = 0
        branches = repo.branchmap()
        for branch in branches:
            heads = repo.branchheads(branch)
            for head in heads:
                (cached, missing) = lfcommands.cachelfiles(ui, repo, head)
                numcached += len(cached)
        ui.status(_("%d largefiles cached\n" % numcached))
    return result

def override_rebase(orig, ui, repo, **opts):
    repo._isrebasing = True
    try:
        orig(ui, repo, **opts)
    finally:
        repo._isrebasing = False

def override_archive(orig, repo, dest, node, kind, decode=True, matchfn=None,
            prefix=None, mtime=None, subrepos=None):
    # No need to lock because we are only reading history and
    # largefile caches, neither of which are modified.
    lfcommands.cachelfiles(repo.ui, repo, node)

    if kind not in archival.archivers:
        raise util.Abort(_("unknown archive type '%s'") % kind)

    ctx = repo[node]

    if kind == 'files':
        if prefix:
            raise util.Abort(
                _('cannot give prefix when archiving to files'))
    else:
        prefix = archival.tidyprefix(dest, kind, prefix)

    def write(name, mode, islink, getdata):
        if matchfn and not matchfn(name):
            return
        data = getdata()
        if decode:
            data = repo.wwritedata(name, data)
        archiver.addfile(prefix + name, mode, islink, data)

    archiver = archival.archivers[kind](dest, mtime or ctx.date()[0])

    if repo.ui.configbool("ui", "archivemeta", True):
        def metadata():
            base = 'repo: %s\nnode: %s\nbranch: %s\n' % (
                hex(repo.changelog.node(0)), hex(node), ctx.branch())

            tags = ''.join('tag: %s\n' % t for t in ctx.tags()
                           if repo.tagtype(t) == 'global')
            if not tags:
                repo.ui.pushbuffer()
                opts = {'template': '{latesttag}\n{latesttagdistance}',
                        'style': '', 'patch': None, 'git': None}
                cmdutil.show_changeset(repo.ui, repo, opts).show(ctx)
                ltags, dist = repo.ui.popbuffer().split('\n')
                tags = ''.join('latesttag: %s\n' % t for t in ltags.split(':'))
                tags += 'latesttagdistance: %s\n' % dist

            return base + tags

        write('.hg_archival.txt', 0644, False, metadata)

    for f in ctx:
        ff = ctx.flags(f)
        getdata = ctx[f].data
        if lfutil.isstandin(f):
            path = lfutil.findfile(repo, getdata().strip())
            if path is None:
                raise util.Abort(
                    _('largefile %s not found in repo store or system cache')
                    % lfutil.splitstandin(f))
            f = lfutil.splitstandin(f)

            def getdatafn():
                fd = None
                try:
                    fd = open(path, 'rb')
                    return fd.read()
                finally:
                    if fd:
                        fd.close()

            getdata = getdatafn
        write(f, 'x' in ff and 0755 or 0644, 'l' in ff, getdata)

    if subrepos:
        for subpath in ctx.substate:
            sub = ctx.sub(subpath)
            sub.archive(repo.ui, archiver, prefix)

    archiver.done()

# If a largefile is modified, the change is not reflected in its
# standin until a commit. cmdutil.bailifchanged() raises an exception
# if the repo has uncommitted changes. Wrap it to also check if
# largefiles were changed. This is used by bisect and backout.
def override_bailifchanged(orig, repo):
    orig(repo)
    repo.lfstatus = True
    modified, added, removed, deleted = repo.status()[:4]
    repo.lfstatus = False
    if modified or added or removed or deleted:
        raise util.Abort(_('outstanding uncommitted changes'))

# Fetch doesn't use cmdutil.bail_if_changed so override it to add the check
def override_fetch(orig, ui, repo, *pats, **opts):
    repo.lfstatus = True
    modified, added, removed, deleted = repo.status()[:4]
    repo.lfstatus = False
    if modified or added or removed or deleted:
        raise util.Abort(_('outstanding uncommitted changes'))
    return orig(ui, repo, *pats, **opts)

def override_forget(orig, ui, repo, *pats, **opts):
    installnormalfilesmatchfn(repo[None].manifest())
    orig(ui, repo, *pats, **opts)
    restorematchfn()
    m = scmutil.match(repo[None], pats, opts)

    try:
        repo.lfstatus = True
        s = repo.status(match=m, clean=True)
    finally:
        repo.lfstatus = False
    forget = sorted(s[0] + s[1] + s[3] + s[6])
    forget = [f for f in forget if lfutil.standin(f) in repo[None].manifest()]

    for f in forget:
        if lfutil.standin(f) not in repo.dirstate and not \
                os.path.isdir(m.rel(lfutil.standin(f))):
            ui.warn(_('not removing %s: file is already untracked\n')
                    % m.rel(f))

    for f in forget:
        if ui.verbose or not m.exact(f):
            ui.status(_('removing %s\n') % m.rel(f))

    # Need to lock because standin files are deleted then removed from the
    # repository and we could race inbetween.
    wlock = repo.wlock()
    try:
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        for f in forget:
            if lfdirstate[f] == 'a':
                lfdirstate.drop(f)
            else:
                lfdirstate.remove(f)
        lfdirstate.write()
        lfutil.repo_remove(repo, [lfutil.standin(f) for f in forget],
            unlink=True)
    finally:
        wlock.release()

def getoutgoinglfiles(ui, repo, dest=None, **opts):
    dest = ui.expandpath(dest or 'default-push', dest or 'default')
    dest, branches = hg.parseurl(dest, opts.get('branch'))
    revs, checkout = hg.addbranchrevs(repo, repo, branches, opts.get('rev'))
    if revs:
        revs = [repo.lookup(rev) for rev in revs]

    remoteui = hg.remoteui

    try:
        remote = hg.repository(remoteui(repo, opts), dest)
    except error.RepoError:
        return None
    o = lfutil.findoutgoing(repo, remote, False)
    if not o:
        return None
    o = repo.changelog.nodesbetween(o, revs)[0]
    if opts.get('newest_first'):
        o.reverse()

    toupload = set()
    for n in o:
        parents = [p for p in repo.changelog.parents(n) if p != node.nullid]
        ctx = repo[n]
        files = set(ctx.files())
        if len(parents) == 2:
            mc = ctx.manifest()
            mp1 = ctx.parents()[0].manifest()
            mp2 = ctx.parents()[1].manifest()
            for f in mp1:
                if f not in mc:
                        files.add(f)
            for f in mp2:
                if f not in mc:
                    files.add(f)
            for f in mc:
                if mc[f] != mp1.get(f, None) or mc[f] != mp2.get(f, None):
                    files.add(f)
        toupload = toupload.union(
            set([f for f in files if lfutil.isstandin(f) and f in ctx]))
    return toupload

def override_outgoing(orig, ui, repo, dest=None, **opts):
    orig(ui, repo, dest, **opts)

    if opts.pop('large', None):
        toupload = getoutgoinglfiles(ui, repo, dest, **opts)
        if toupload is None:
            ui.status(_('largefiles: No remote repo\n'))
        else:
            ui.status(_('largefiles to upload:\n'))
            for file in toupload:
                ui.status(lfutil.splitstandin(file) + '\n')
            ui.status('\n')

def override_summary(orig, ui, repo, *pats, **opts):
    try:
        repo.lfstatus = True
        orig(ui, repo, *pats, **opts)
    finally:
        repo.lfstatus = False

    if opts.pop('large', None):
        toupload = getoutgoinglfiles(ui, repo, None, **opts)
        if toupload is None:
            ui.status(_('largefiles: No remote repo\n'))
        else:
            ui.status(_('largefiles: %d to upload\n') % len(toupload))

def override_addremove(orig, ui, repo, *pats, **opts):
    # Get the list of missing largefiles so we can remove them
    lfdirstate = lfutil.openlfdirstate(ui, repo)
    s = lfdirstate.status(match_.always(repo.root, repo.getcwd()), [], False,
        False, False)
    (unsure, modified, added, removed, missing, unknown, ignored, clean) = s

    # Call into the normal remove code, but the removing of the standin, we want
    # to have handled by original addremove.  Monkey patching here makes sure
    # we don't remove the standin in the largefiles code, preventing a very
    # confused state later.
    repo._isaddremove = True
    remove_largefiles(ui, repo, *missing, **opts)
    repo._isaddremove = False
    # Call into the normal add code, and any files that *should* be added as
    # largefiles will be
    add_largefiles(ui, repo, *pats, **opts)
    # Now that we've handled largefiles, hand off to the original addremove
    # function to take care of the rest.  Make sure it doesn't do anything with
    # largefiles by installing a matcher that will ignore them.
    installnormalfilesmatchfn(repo[None].manifest())
    result = orig(ui, repo, *pats, **opts)
    restorematchfn()
    return result

# Calling purge with --all will cause the largefiles to be deleted.
# Override repo.status to prevent this from happening.
def override_purge(orig, ui, repo, *dirs, **opts):
    oldstatus = repo.status
    def override_status(node1='.', node2=None, match=None, ignored=False,
                        clean=False, unknown=False, listsubrepos=False):
        r = oldstatus(node1, node2, match, ignored, clean, unknown,
                      listsubrepos)
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        modified, added, removed, deleted, unknown, ignored, clean = r
        unknown = [f for f in unknown if lfdirstate[f] == '?']
        ignored = [f for f in ignored if lfdirstate[f] == '?']
        return modified, added, removed, deleted, unknown, ignored, clean
    repo.status = override_status
    orig(ui, repo, *dirs, **opts)
    repo.status = oldstatus

def override_rollback(orig, ui, repo, **opts):
    result = orig(ui, repo, **opts)
    merge.update(repo, node=None, branchmerge=False, force=True,
        partial=lfutil.isstandin)
    wlock = repo.wlock()
    try:
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        lfiles = lfutil.listlfiles(repo)
        oldlfiles = lfutil.listlfiles(repo, repo[None].parents()[0].rev())
        for file in lfiles:
            if file in oldlfiles:
                lfdirstate.normallookup(file)
            else:
                lfdirstate.add(file)
        lfdirstate.write()
    finally:
        wlock.release()
    return result

def override_transplant(orig, ui, repo, *revs, **opts):
    result = orig(ui, repo, *revs, **opts)
    lfcommands.updatelfiles(repo.ui, repo)
    return result