hgext/largefiles/lfcommands.py

windows: seek to the end of posixfile when opening in append mode

The position is implementation defined when opening in append mode,
and it seems like Linux sets it to EOF while Windows keeps it at zero.
This has caused problems in the past when a file is opened and tell()
is immediately called, such as 48c232873a54 and 6bf93440a717.

Since the only caller of osutil.posixfile is this windows module, this seems
like a better place to fix the issue than in osutil.c and pure.osutil.

# 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.

'''High-level command function for lfconvert, plus the cmdtable.'''

import os, errno
import shutil

from mercurial import util, match as match_, hg, node, context, error, \
    cmdutil, scmutil, commands
from mercurial.i18n import _
from mercurial.lock import release

import lfutil
import basestore

# -- Commands ----------------------------------------------------------

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

@command('lfconvert',
    [('s', 'size', '',
      _('minimum size (MB) for files to be converted as largefiles'), 'SIZE'),
    ('', 'to-normal', False,
     _('convert from a largefiles repo to a normal repo')),
    ],
    _('hg lfconvert SOURCE DEST [FILE ...]'),
    norepo=True,
    inferrepo=True)
def lfconvert(ui, src, dest, *pats, **opts):
    '''convert a normal repository to a largefiles repository

    Convert repository SOURCE to a new repository DEST, identical to
    SOURCE except that certain files will be converted as largefiles:
    specifically, any file that matches any PATTERN *or* whose size is
    above the minimum size threshold is converted as a largefile. The
    size used to determine whether or not to track a file as a
    largefile is the size of the first version of the file. The
    minimum size can be specified either with --size or in
    configuration as ``largefiles.size``.

    After running this command you will need to make sure that
    largefiles is enabled anywhere you intend to push the new
    repository.

    Use --to-normal to convert largefiles back to normal files; after
    this, the DEST repository can be used without largefiles at all.'''

    if opts['to_normal']:
        tolfile = False
    else:
        tolfile = True
        size = lfutil.getminsize(ui, True, opts.get('size'), default=None)

    if not hg.islocal(src):
        raise util.Abort(_('%s is not a local Mercurial repo') % src)
    if not hg.islocal(dest):
        raise util.Abort(_('%s is not a local Mercurial repo') % dest)

    rsrc = hg.repository(ui, src)
    ui.status(_('initializing destination %s\n') % dest)
    rdst = hg.repository(ui, dest, create=True)

    success = False
    dstwlock = dstlock = None
    try:
        # Lock destination to prevent modification while it is converted to.
        # Don't need to lock src because we are just reading from its history
        # which can't change.
        dstwlock = rdst.wlock()
        dstlock = rdst.lock()

        # Get a list of all changesets in the source.  The easy way to do this
        # is to simply walk the changelog, using changelog.nodesbetween().
        # Take a look at mercurial/revlog.py:639 for more details.
        # Use a generator instead of a list to decrease memory usage
        ctxs = (rsrc[ctx] for ctx in rsrc.changelog.nodesbetween(None,
            rsrc.heads())[0])
        revmap = {node.nullid: node.nullid}
        if tolfile:
            lfiles = set()
            normalfiles = set()
            if not pats:
                pats = ui.configlist(lfutil.longname, 'patterns', default=[])
            if pats:
                matcher = match_.match(rsrc.root, '', list(pats))
            else:
                matcher = None

            lfiletohash = {}
            for ctx in ctxs:
                ui.progress(_('converting revisions'), ctx.rev(),
                    unit=_('revision'), total=rsrc['tip'].rev())
                _lfconvert_addchangeset(rsrc, rdst, ctx, revmap,
                    lfiles, normalfiles, matcher, size, lfiletohash)
            ui.progress(_('converting revisions'), None)

            if os.path.exists(rdst.wjoin(lfutil.shortname)):
                shutil.rmtree(rdst.wjoin(lfutil.shortname))

            for f in lfiletohash.keys():
                if os.path.isfile(rdst.wjoin(f)):
                    os.unlink(rdst.wjoin(f))
                try:
                    os.removedirs(os.path.dirname(rdst.wjoin(f)))
                except OSError:
                    pass

            # If there were any files converted to largefiles, add largefiles
            # to the destination repository's requirements.
            if lfiles:
                rdst.requirements.add('largefiles')
                rdst._writerequirements()
        else:
            for ctx in ctxs:
                ui.progress(_('converting revisions'), ctx.rev(),
                    unit=_('revision'), total=rsrc['tip'].rev())
                _addchangeset(ui, rsrc, rdst, ctx, revmap)

            ui.progress(_('converting revisions'), None)
        success = True
    finally:
        rdst.dirstate.clear()
        release(dstlock, dstwlock)
        if not success:
            # we failed, remove the new directory
            shutil.rmtree(rdst.root)

def _addchangeset(ui, rsrc, rdst, ctx, revmap):
    # Convert src parents to dst parents
    parents = _convertparents(ctx, revmap)

    # Generate list of changed files
    files = _getchangedfiles(ctx, parents)

    def getfilectx(repo, memctx, f):
        if lfutil.standin(f) in files:
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            try:
                fctx = ctx.filectx(lfutil.standin(f))
            except error.LookupError:
                return None
            renamed = fctx.renamed()
            if renamed:
                renamed = lfutil.splitstandin(renamed[0])

            hash = fctx.data().strip()
            path = lfutil.findfile(rsrc, hash)

            # If one file is missing, likely all files from this rev are
            if path is None:
                cachelfiles(ui, rsrc, ctx.node())
                path = lfutil.findfile(rsrc, hash)

                if path is None:
                    raise util.Abort(
                        _("missing largefile \'%s\' from revision %s")
                         % (f, node.hex(ctx.node())))

            data = ''
            fd = None
            try:
                fd = open(path, 'rb')
                data = fd.read()
            finally:
                if fd:
                    fd.close()
            return context.memfilectx(repo, f, data, 'l' in fctx.flags(),
                                      'x' in fctx.flags(), renamed)
        else:
            return _getnormalcontext(repo, ctx, f, revmap)

    dstfiles = []
    for file in files:
        if lfutil.isstandin(file):
            dstfiles.append(lfutil.splitstandin(file))
        else:
            dstfiles.append(file)
    # Commit
    _commitcontext(rdst, parents, ctx, dstfiles, getfilectx, revmap)

def _lfconvert_addchangeset(rsrc, rdst, ctx, revmap, lfiles, normalfiles,
        matcher, size, lfiletohash):
    # Convert src parents to dst parents
    parents = _convertparents(ctx, revmap)

    # Generate list of changed files
    files = _getchangedfiles(ctx, parents)

    dstfiles = []
    for f in files:
        if f not in lfiles and f not in normalfiles:
            islfile = _islfile(f, ctx, matcher, size)
            # If this file was renamed or copied then copy
            # the largefile-ness of its predecessor
            if f in ctx.manifest():
                fctx = ctx.filectx(f)
                renamed = fctx.renamed()
                renamedlfile = renamed and renamed[0] in lfiles
                islfile |= renamedlfile
                if 'l' in fctx.flags():
                    if renamedlfile:
                        raise util.Abort(
                            _('renamed/copied largefile %s becomes symlink')
                            % f)
                    islfile = False
            if islfile:
                lfiles.add(f)
            else:
                normalfiles.add(f)

        if f in lfiles:
            dstfiles.append(lfutil.standin(f))
            # largefile in manifest if it has not been removed/renamed
            if f in ctx.manifest():
                fctx = ctx.filectx(f)
                if 'l' in fctx.flags():
                    renamed = fctx.renamed()
                    if renamed and renamed[0] in lfiles:
                        raise util.Abort(_('largefile %s becomes symlink') % f)

                # largefile was modified, update standins
                m = util.sha1('')
                m.update(ctx[f].data())
                hash = m.hexdigest()
                if f not in lfiletohash or lfiletohash[f] != hash:
                    rdst.wwrite(f, ctx[f].data(), ctx[f].flags())
                    executable = 'x' in ctx[f].flags()
                    lfutil.writestandin(rdst, lfutil.standin(f), hash,
                        executable)
                    lfiletohash[f] = hash
        else:
            # normal file
            dstfiles.append(f)

    def getfilectx(repo, memctx, f):
        if lfutil.isstandin(f):
            # if the file isn't in the manifest then it was removed
            # or renamed, raise IOError to indicate this
            srcfname = lfutil.splitstandin(f)
            try:
                fctx = ctx.filectx(srcfname)
            except error.LookupError:
                return None
            renamed = fctx.renamed()
            if renamed:
                # standin is always a largefile because largefile-ness
                # doesn't change after rename or copy
                renamed = lfutil.standin(renamed[0])

            return context.memfilectx(repo, f, lfiletohash[srcfname] + '\n',
                                      'l' in fctx.flags(), 'x' in fctx.flags(),
                                      renamed)
        else:
            return _getnormalcontext(repo, ctx, f, revmap)

    # Commit
    _commitcontext(rdst, parents, ctx, dstfiles, getfilectx, revmap)

def _commitcontext(rdst, parents, ctx, dstfiles, getfilectx, revmap):
    mctx = context.memctx(rdst, parents, ctx.description(), dstfiles,
                          getfilectx, ctx.user(), ctx.date(), ctx.extra())
    ret = rdst.commitctx(mctx)
    lfutil.copyalltostore(rdst, ret)
    rdst.setparents(ret)
    revmap[ctx.node()] = rdst.changelog.tip()

# Generate list of changed files
def _getchangedfiles(ctx, parents):
    files = set(ctx.files())
    if node.nullid not in parents:
        mc = ctx.manifest()
        mp1 = ctx.parents()[0].manifest()
        mp2 = ctx.parents()[1].manifest()
        files |= (set(mp1) | set(mp2)) - set(mc)
        for f in mc:
            if mc[f] != mp1.get(f, None) or mc[f] != mp2.get(f, None):
                files.add(f)
    return files

# Convert src parents to dst parents
def _convertparents(ctx, revmap):
    parents = []
    for p in ctx.parents():
        parents.append(revmap[p.node()])
    while len(parents) < 2:
        parents.append(node.nullid)
    return parents

# Get memfilectx for a normal file
def _getnormalcontext(repo, ctx, f, revmap):
    try:
        fctx = ctx.filectx(f)
    except error.LookupError:
        return None
    renamed = fctx.renamed()
    if renamed:
        renamed = renamed[0]

    data = fctx.data()
    if f == '.hgtags':
        data = _converttags (repo.ui, revmap, data)
    return context.memfilectx(repo, f, data, 'l' in fctx.flags(),
                              'x' in fctx.flags(), renamed)

# Remap tag data using a revision map
def _converttags(ui, revmap, data):
    newdata = []
    for line in data.splitlines():
        try:
            id, name = line.split(' ', 1)
        except ValueError:
            ui.warn(_('skipping incorrectly formatted tag %s\n')
                % line)
            continue
        try:
            newid = node.bin(id)
        except TypeError:
            ui.warn(_('skipping incorrectly formatted id %s\n')
                % id)
            continue
        try:
            newdata.append('%s %s\n' % (node.hex(revmap[newid]),
                name))
        except KeyError:
            ui.warn(_('no mapping for id %s\n') % id)
            continue
    return ''.join(newdata)

def _islfile(file, ctx, matcher, size):
    '''Return true if file should be considered a largefile, i.e.
    matcher matches it or it is larger than size.'''
    # never store special .hg* files as largefiles
    if file == '.hgtags' or file == '.hgignore' or file == '.hgsigs':
        return False
    if matcher and matcher(file):
        return True
    try:
        return ctx.filectx(file).size() >= size * 1024 * 1024
    except error.LookupError:
        return False

def uploadlfiles(ui, rsrc, rdst, files):
    '''upload largefiles to the central store'''

    if not files:
        return

    store = basestore._openstore(rsrc, rdst, put=True)

    at = 0
    ui.debug("sending statlfile command for %d largefiles\n" % len(files))
    retval = store.exists(files)
    files = filter(lambda h: not retval[h], files)
    ui.debug("%d largefiles need to be uploaded\n" % len(files))

    for hash in files:
        ui.progress(_('uploading largefiles'), at, unit='largefile',
                    total=len(files))
        source = lfutil.findfile(rsrc, hash)
        if not source:
            raise util.Abort(_('largefile %s missing from store'
                               ' (needs to be uploaded)') % hash)
        # XXX check for errors here
        store.put(source, hash)
        at += 1
    ui.progress(_('uploading largefiles'), None)

def verifylfiles(ui, repo, all=False, contents=False):
    '''Verify that every largefile revision in the current changeset
    exists in the central store.  With --contents, also verify that
    the contents of each local largefile file revision are correct (SHA-1 hash
    matches the revision ID).  With --all, check every changeset in
    this repository.'''
    if all:
        # Pass a list to the function rather than an iterator because we know a
        # list will work.
        revs = range(len(repo))
    else:
        revs = ['.']

    store = basestore._openstore(repo)
    return store.verify(revs, contents=contents)

def cachelfiles(ui, repo, node, filelist=None):
    '''cachelfiles ensures that all largefiles needed by the specified revision
    are present in the repository's largefile cache.

    returns a tuple (cached, missing).  cached is the list of files downloaded
    by this operation; missing is the list of files that were needed but could
    not be found.'''
    lfiles = lfutil.listlfiles(repo, node)
    if filelist:
        lfiles = set(lfiles) & set(filelist)
    toget = []

    for lfile in lfiles:
        try:
            expectedhash = repo[node][lfutil.standin(lfile)].data().strip()
        except IOError, err:
            if err.errno == errno.ENOENT:
                continue # node must be None and standin wasn't found in wctx
            raise
        if not lfutil.findfile(repo, expectedhash):
            toget.append((lfile, expectedhash))

    if toget:
        store = basestore._openstore(repo)
        ret = store.get(toget)
        return ret

    return ([], [])

def downloadlfiles(ui, repo, rev=None):
    matchfn = scmutil.match(repo[None],
                            [repo.wjoin(lfutil.shortname)], {})
    def prepare(ctx, fns):
        pass
    totalsuccess = 0
    totalmissing = 0
    if rev != []: # walkchangerevs on empty list would return all revs
        for ctx in cmdutil.walkchangerevs(repo, matchfn, {'rev' : rev},
                                          prepare):
            success, missing = cachelfiles(ui, repo, ctx.node())
            totalsuccess += len(success)
            totalmissing += len(missing)
    ui.status(_("%d additional largefiles cached\n") % totalsuccess)
    if totalmissing > 0:
        ui.status(_("%d largefiles failed to download\n") % totalmissing)
    return totalsuccess, totalmissing

def updatelfiles(ui, repo, filelist=None, printmessage=None,
                 normallookup=False, checked=False):
    '''Update largefiles according to standins in the working directory

    If ``printmessage`` is other than ``None``, it means "print (or
    ignore, for false) message forcibly".
    '''
    statuswriter = lfutil.getstatuswriter(ui, repo, printmessage)
    wlock = repo.wlock()
    try:
        lfdirstate = lfutil.openlfdirstate(ui, repo)
        lfiles = set(lfutil.listlfiles(repo)) | set(lfdirstate)

        if filelist is not None:
            filelist = set(filelist)
            lfiles = [f for f in lfiles if f in filelist]

        update = {}
        updated, removed = 0, 0
        for lfile in lfiles:
            abslfile = repo.wjoin(lfile)
            absstandin = repo.wjoin(lfutil.standin(lfile))
            if os.path.exists(absstandin):
                if (os.path.exists(absstandin + '.orig') and
                    os.path.exists(abslfile)):
                    shutil.copyfile(abslfile, abslfile + '.orig')
                    util.unlinkpath(absstandin + '.orig')
                expecthash = lfutil.readstandin(repo, lfile)
                if (expecthash != '' and
                    (checked or
                     not os.path.exists(abslfile) or
                     expecthash != lfutil.hashfile(abslfile))):
                    if lfile not in repo[None]: # not switched to normal file
                        util.unlinkpath(abslfile, ignoremissing=True)
                    # use normallookup() to allocate an entry in largefiles
                    # dirstate, because lack of it misleads
                    # lfilesrepo.status() into recognition that such cache
                    # missing files are removed.
                    lfdirstate.normallookup(lfile)
                    update[lfile] = expecthash
            else:
                # Remove lfiles for which the standin is deleted, unless the
                # lfile is added to the repository again. This happens when a
                # largefile is converted back to a normal file: the standin
                # disappears, but a new (normal) file appears as the lfile.
                if (os.path.exists(abslfile) and
                    repo.dirstate.normalize(lfile) not in repo[None]):
                    util.unlinkpath(abslfile)
                    removed += 1

        # largefile processing might be slow and be interrupted - be prepared
        lfdirstate.write()

        if lfiles:
            statuswriter(_('getting changed largefiles\n'))
            cachelfiles(ui, repo, None, lfiles)

        for lfile in lfiles:
            update1 = 0

            expecthash = update.get(lfile)
            if expecthash:
                if not lfutil.copyfromcache(repo, expecthash, lfile):
                    # failed ... but already removed and set to normallookup
                    continue
                # Synchronize largefile dirstate to the last modified
                # time of the file
                lfdirstate.normal(lfile)
                update1 = 1

            # copy the state of largefile standin from the repository's
            # dirstate to its state in the lfdirstate.
            abslfile = repo.wjoin(lfile)
            absstandin = repo.wjoin(lfutil.standin(lfile))
            if os.path.exists(absstandin):
                mode = os.stat(absstandin).st_mode
                if mode != os.stat(abslfile).st_mode:
                    os.chmod(abslfile, mode)
                    update1 = 1

            updated += update1

            lfutil.synclfdirstate(repo, lfdirstate, lfile, normallookup)

        lfdirstate.write()
        if lfiles:
            statuswriter(_('%d largefiles updated, %d removed\n') % (updated,
                removed))
    finally:
        wlock.release()

@command('lfpull',
    [('r', 'rev', [], _('pull largefiles for these revisions'))
    ] + commands.remoteopts,
    _('-r REV... [-e CMD] [--remotecmd CMD] [SOURCE]'))
def lfpull(ui, repo, source="default", **opts):
    """pull largefiles for the specified revisions from the specified source

    Pull largefiles that are referenced from local changesets but missing
    locally, pulling from a remote repository to the local cache.

    If SOURCE is omitted, the 'default' path will be used.
    See :hg:`help urls` for more information.

    .. container:: verbose

      Some examples:

      - pull largefiles for all branch heads::

          hg lfpull -r "head() and not closed()"

      - pull largefiles on the default branch::

          hg lfpull -r "branch(default)"
    """
    repo.lfpullsource = source

    revs = opts.get('rev', [])
    if not revs:
        raise util.Abort(_('no revisions specified'))
    revs = scmutil.revrange(repo, revs)

    numcached = 0
    for rev in revs:
        ui.note(_('pulling largefiles for revision %s\n') % rev)
        (cached, missing) = cachelfiles(ui, repo, rev)
        numcached += len(cached)
    ui.status(_("%d largefiles cached\n") % numcached)