view hgext/largefiles/reposetup.py @ 45095:8e04607023e5

procutil: ensure that procutil.std{out,err}.write() writes all bytes

Python 3 offers different kind of streams and it’s not guaranteed for all of
them that calling write() writes all bytes.

When Python is started in unbuffered mode, sys.std{out,err}.buffer are
instances of io.FileIO, whose write() can write less bytes for
platform-specific reasons (e.g. Linux has a 0x7ffff000 bytes maximum and could
write less if interrupted by a signal; when writing to Windows consoles, it’s
limited to 32767 bytes to avoid the "not enough space" error). This can lead to
silent loss of data, both when using sys.std{out,err}.buffer (which may in fact
not be a buffered stream) and when using the text streams sys.std{out,err}
(I’ve created a CPython bug report for that:
https://bugs.python.org/issue41221).

Python may fix the problem at some point. For now, we implement our own wrapper
for procutil.std{out,err} that calls the raw stream’s write() method until all
bytes have been written. We don’t use sys.std{out,err} for larger writes, so I
think it’s not worth the effort to patch them.

# 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.

'''setup for largefiles repositories: reposetup'''
from __future__ import absolute_import

import copy

from mercurial.i18n import _

from mercurial import (
    error,
    extensions,
    localrepo,
    match as matchmod,
    scmutil,
    util,
)

from . import (
    lfcommands,
    lfutil,
)


def reposetup(ui, repo):
    # wire repositories should be given new wireproto functions
    # by "proto.wirereposetup()" via "hg.wirepeersetupfuncs"
    if not repo.local():
        return

    class lfilesrepo(repo.__class__):
        # the mark to examine whether "repo" object enables largefiles or not
        _largefilesenabled = True

        lfstatus = False

        # When lfstatus is set, return a context that gives the names
        # of largefiles instead of their corresponding standins and
        # identifies the largefiles as always binary, regardless of
        # their actual contents.
        def __getitem__(self, changeid):
            ctx = super(lfilesrepo, self).__getitem__(changeid)
            if self.lfstatus:

                def files(orig):
                    filenames = orig()
                    return [lfutil.splitstandin(f) or f for f in filenames]

                extensions.wrapfunction(ctx, 'files', files)

                def manifest(orig):
                    man1 = orig()

                    class lfilesmanifest(man1.__class__):
                        def __contains__(self, filename):
                            orig = super(lfilesmanifest, self).__contains__
                            return orig(filename) or orig(
                                lfutil.standin(filename)
                            )

                    man1.__class__ = lfilesmanifest
                    return man1

                extensions.wrapfunction(ctx, 'manifest', manifest)

                def filectx(orig, path, fileid=None, filelog=None):
                    try:
                        if filelog is not None:
                            result = orig(path, fileid, filelog)
                        else:
                            result = orig(path, fileid)
                    except error.LookupError:
                        # Adding a null character will cause Mercurial to
                        # identify this as a binary file.
                        if filelog is not None:
                            result = orig(lfutil.standin(path), fileid, filelog)
                        else:
                            result = orig(lfutil.standin(path), fileid)
                        olddata = result.data
                        result.data = lambda: olddata() + b'\0'
                    return result

                extensions.wrapfunction(ctx, 'filectx', filectx)

            return ctx

        # Figure out the status of big files and insert them into the
        # appropriate list in the result. Also removes standin files
        # from the listing. Revert to the original status if
        # self.lfstatus is False.
        # XXX large file status is buggy when used on repo proxy.
        # XXX this needs to be investigated.
        @localrepo.unfilteredmethod
        def status(
            self,
            node1=b'.',
            node2=None,
            match=None,
            ignored=False,
            clean=False,
            unknown=False,
            listsubrepos=False,
        ):
            listignored, listclean, listunknown = ignored, clean, unknown
            orig = super(lfilesrepo, self).status
            if not self.lfstatus:
                return orig(
                    node1,
                    node2,
                    match,
                    listignored,
                    listclean,
                    listunknown,
                    listsubrepos,
                )

            # some calls in this function rely on the old version of status
            self.lfstatus = False
            ctx1 = self[node1]
            ctx2 = self[node2]
            working = ctx2.rev() is None
            parentworking = working and ctx1 == self[b'.']

            if match is None:
                match = matchmod.always()

            try:
                # updating the dirstate is optional
                # so we don't wait on the lock
                wlock = self.wlock(False)
                gotlock = True
            except error.LockError:
                wlock = util.nullcontextmanager()
                gotlock = False
            with wlock:

                # First check if paths or patterns were specified on the
                # command line.  If there were, and they don't match any
                # largefiles, we should just bail here and let super
                # handle it -- thus gaining a big performance boost.
                lfdirstate = lfutil.openlfdirstate(ui, self)
                if not match.always():
                    for f in lfdirstate:
                        if match(f):
                            break
                    else:
                        return orig(
                            node1,
                            node2,
                            match,
                            listignored,
                            listclean,
                            listunknown,
                            listsubrepos,
                        )

                # Create a copy of match that matches standins instead
                # of largefiles.
                def tostandins(files):
                    if not working:
                        return files
                    newfiles = []
                    dirstate = self.dirstate
                    for f in files:
                        sf = lfutil.standin(f)
                        if sf in dirstate:
                            newfiles.append(sf)
                        elif dirstate.hasdir(sf):
                            # Directory entries could be regular or
                            # standin, check both
                            newfiles.extend((f, sf))
                        else:
                            newfiles.append(f)
                    return newfiles

                m = copy.copy(match)
                m._files = tostandins(m._files)

                result = orig(
                    node1, node2, m, ignored, clean, unknown, listsubrepos
                )
                if working:

                    def sfindirstate(f):
                        sf = lfutil.standin(f)
                        dirstate = self.dirstate
                        return sf in dirstate or dirstate.hasdir(sf)

                    match._files = [f for f in match._files if sfindirstate(f)]
                    # Don't waste time getting the ignored and unknown
                    # files from lfdirstate
                    unsure, s = lfdirstate.status(
                        match,
                        subrepos=[],
                        ignored=False,
                        clean=listclean,
                        unknown=False,
                    )
                    (modified, added, removed, deleted, clean) = (
                        s.modified,
                        s.added,
                        s.removed,
                        s.deleted,
                        s.clean,
                    )
                    if parentworking:
                        for lfile in unsure:
                            standin = lfutil.standin(lfile)
                            if standin not in ctx1:
                                # from second parent
                                modified.append(lfile)
                            elif lfutil.readasstandin(
                                ctx1[standin]
                            ) != lfutil.hashfile(self.wjoin(lfile)):
                                modified.append(lfile)
                            else:
                                if listclean:
                                    clean.append(lfile)
                                lfdirstate.normal(lfile)
                    else:
                        tocheck = unsure + modified + added + clean
                        modified, added, clean = [], [], []
                        checkexec = self.dirstate._checkexec

                        for lfile in tocheck:
                            standin = lfutil.standin(lfile)
                            if standin in ctx1:
                                abslfile = self.wjoin(lfile)
                                if (
                                    lfutil.readasstandin(ctx1[standin])
                                    != lfutil.hashfile(abslfile)
                                ) or (
                                    checkexec
                                    and (b'x' in ctx1.flags(standin))
                                    != bool(lfutil.getexecutable(abslfile))
                                ):
                                    modified.append(lfile)
                                elif listclean:
                                    clean.append(lfile)
                            else:
                                added.append(lfile)

                        # at this point, 'removed' contains largefiles
                        # marked as 'R' in the working context.
                        # then, largefiles not managed also in the target
                        # context should be excluded from 'removed'.
                        removed = [
                            lfile
                            for lfile in removed
                            if lfutil.standin(lfile) in ctx1
                        ]

                    # Standins no longer found in lfdirstate have been deleted
                    for standin in ctx1.walk(lfutil.getstandinmatcher(self)):
                        lfile = lfutil.splitstandin(standin)
                        if not match(lfile):
                            continue
                        if lfile not in lfdirstate:
                            deleted.append(lfile)
                            # Sync "largefile has been removed" back to the
                            # standin. Removing a file as a side effect of
                            # running status is gross, but the alternatives (if
                            # any) are worse.
                            self.wvfs.unlinkpath(standin, ignoremissing=True)

                    # Filter result lists
                    result = list(result)

                    # Largefiles are not really removed when they're
                    # still in the normal dirstate. Likewise, normal
                    # files are not really removed if they are still in
                    # lfdirstate. This happens in merges where files
                    # change type.
                    removed = [f for f in removed if f not in self.dirstate]
                    result[2] = [f for f in result[2] if f not in lfdirstate]

                    lfiles = set(lfdirstate)
                    # Unknown files
                    result[4] = set(result[4]).difference(lfiles)
                    # Ignored files
                    result[5] = set(result[5]).difference(lfiles)
                    # combine normal files and largefiles
                    normals = [
                        [fn for fn in filelist if not lfutil.isstandin(fn)]
                        for filelist in result
                    ]
                    lfstatus = (
                        modified,
                        added,
                        removed,
                        deleted,
                        [],
                        [],
                        clean,
                    )
                    result = [
                        sorted(list1 + list2)
                        for (list1, list2) in zip(normals, lfstatus)
                    ]
                else:  # not against working directory
                    result = [
                        [lfutil.splitstandin(f) or f for f in items]
                        for items in result
                    ]

                if gotlock:
                    lfdirstate.write()

            self.lfstatus = True
            return scmutil.status(*result)

        def commitctx(self, ctx, *args, **kwargs):
            node = super(lfilesrepo, self).commitctx(ctx, *args, **kwargs)

            class lfilesctx(ctx.__class__):
                def markcommitted(self, node):
                    orig = super(lfilesctx, self).markcommitted
                    return lfutil.markcommitted(orig, self, node)

            ctx.__class__ = lfilesctx
            return node

        # Before commit, largefile standins have not had their
        # contents updated to reflect the hash of their largefile.
        # Do that here.
        def commit(
            self,
            text=b"",
            user=None,
            date=None,
            match=None,
            force=False,
            editor=False,
            extra=None,
        ):
            if extra is None:
                extra = {}
            orig = super(lfilesrepo, self).commit

            with self.wlock():
                lfcommithook = self._lfcommithooks[-1]
                match = lfcommithook(self, match)
                result = orig(
                    text=text,
                    user=user,
                    date=date,
                    match=match,
                    force=force,
                    editor=editor,
                    extra=extra,
                )
                return result

        # TODO: _subdirlfs should be moved into "lfutil.py", because
        # it is referred only from "lfutil.updatestandinsbymatch"
        def _subdirlfs(self, files, lfiles):
            '''
            Adjust matched file list
            If we pass a directory to commit whose only committable files
            are largefiles, the core commit code aborts before finding
            the largefiles.
            So we do the following:
            For directories that only have largefiles as matches,
            we explicitly add the largefiles to the match list and remove
            the directory.
            In other cases, we leave the match list unmodified.
            '''
            actualfiles = []
            dirs = []
            regulars = []

            for f in files:
                if lfutil.isstandin(f + b'/'):
                    raise error.Abort(
                        _(b'file "%s" is a largefile standin') % f,
                        hint=b'commit the largefile itself instead',
                    )
                # Scan directories
                if self.wvfs.isdir(f):
                    dirs.append(f)
                else:
                    regulars.append(f)

            for f in dirs:
                matcheddir = False
                d = self.dirstate.normalize(f) + b'/'
                # Check for matched normal files
                for mf in regulars:
                    if self.dirstate.normalize(mf).startswith(d):
                        actualfiles.append(f)
                        matcheddir = True
                        break
                if not matcheddir:
                    # If no normal match, manually append
                    # any matching largefiles
                    for lf in lfiles:
                        if self.dirstate.normalize(lf).startswith(d):
                            actualfiles.append(lf)
                            if not matcheddir:
                                # There may still be normal files in the dir, so
                                # add a directory to the list, which
                                # forces status/dirstate to walk all files and
                                # call the match function on the matcher, even
                                # on case sensitive filesystems.
                                actualfiles.append(b'.')
                                matcheddir = True
                # Nothing in dir, so readd it
                # and let commit reject it
                if not matcheddir:
                    actualfiles.append(f)

            # Always add normal files
            actualfiles += regulars
            return actualfiles

    repo.__class__ = lfilesrepo

    # stack of hooks being executed before committing.
    # only last element ("_lfcommithooks[-1]") is used for each committing.
    repo._lfcommithooks = [lfutil.updatestandinsbymatch]

    # Stack of status writer functions taking "*msg, **opts" arguments
    # like "ui.status()". Only last element ("_lfstatuswriters[-1]")
    # is used to write status out.
    repo._lfstatuswriters = [ui.status]

    def prepushoutgoinghook(pushop):
        """Push largefiles for pushop before pushing revisions."""
        lfrevs = pushop.lfrevs
        if lfrevs is None:
            lfrevs = pushop.outgoing.missing
        if lfrevs:
            toupload = set()
            addfunc = lambda fn, lfhash: toupload.add(lfhash)
            lfutil.getlfilestoupload(pushop.repo, lfrevs, addfunc)
            lfcommands.uploadlfiles(ui, pushop.repo, pushop.remote, toupload)

    repo.prepushoutgoinghooks.add(b"largefiles", prepushoutgoinghook)

    def checkrequireslfiles(ui, repo, **kwargs):
        if b'largefiles' not in repo.requirements and any(
            lfutil.shortname + b'/' in f[0] for f in repo.store.datafiles()
        ):
            repo.requirements.add(b'largefiles')
            repo._writerequirements()

    ui.setconfig(
        b'hooks', b'changegroup.lfiles', checkrequireslfiles, b'largefiles'
    )
    ui.setconfig(b'hooks', b'commit.lfiles', checkrequireslfiles, b'largefiles')