view mercurial/repair.py @ 33390:32331f54930c

hgweb: re-implement followlines UI selection using buttons

This changeset attempts to solve two issues with the "followlines" UI in
hgweb. First the "followlines" action is currently not easily discoverable
(one has to hover on a line for some time, wait for the invite message to
appear and then perform some action). Second, it gets in the way of natural
line selection, especially in filerevision view.

This changeset introduces an additional markup element (a <button
class="btn-followlines">) alongside each content line of the view. This button
now holds events for line selection that were previously plugged onto content
lines directly. Consequently, there's no more action on content lines, hence
restoring the "natural line selection" behavior (solving the second problem).
These buttons are hidden by default and get displayed upon hover of content
lines; then upon hover of a button itself, a text inviting followlines section
shows up. This solves the first problem (discoverability) as we now have a
clear visual element indicating that "some action could be perform" (i.e. a
button) and that is self-documented.

In followlines.js, all event listeners are now attached to these <button>
elements. The custom "floating tooltip" element is dropped as <button>
elements are now self-documented through a "title" attribute that changes
depending on preceding actions (selection started or not, in particular).

The new <button> element is inserted in followlines.js script (thus only
visible if JavaScript is activated); it contains a "+" and "-" with a
"diff-semantics" style; upon hover, it scales up.

To find the parent element under which to insert the <button> we either rely
on the "data-selectabletag" attribute (which defines the HTML tag of children
of class="sourcelines" element e.g. <span> for filerevision view and <tr> for
annotate view) or use a child of the latter elements if we find an element
with class="followlines-btn-parent" (useful for annotate view, for which we
have to find the <td> in which to insert the <button>).

On noticeable change in CSS concerns the "margin-left" of span:before
pseudo-elements in filelog view that has been increased a bit in order to
leave space for the new button to appear between line number column and
line content one.
Also note the "z-index" addition for "annotate-info" box so that the latter
appears on top of new buttons (instead of getting hidden).

In some respect, the UI similar to line commenting feature that is implemented
in popular code hosting site like GitHub, BitBucket or Kallithea.

# repair.py - functions for repository repair for mercurial
#
# Copyright 2005, 2006 Chris Mason <[e-mail]>
# Copyright 2007 Matt Mackall
#
# 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 errno
import hashlib

from .i18n import _
from .node import short
from . import (
    bundle2,
    changegroup,
    discovery,
    error,
    exchange,
    obsolete,
    obsutil,
    util,
)

def _bundle(repo, bases, heads, node, suffix, compress=True, obsolescence=True):
    """create a bundle with the specified revisions as a backup"""

    backupdir = "strip-backup"
    vfs = repo.vfs
    if not vfs.isdir(backupdir):
        vfs.mkdir(backupdir)

    # Include a hash of all the nodes in the filename for uniqueness
    allcommits = repo.set('%ln::%ln', bases, heads)
    allhashes = sorted(c.hex() for c in allcommits)
    totalhash = hashlib.sha1(''.join(allhashes)).hexdigest()
    name = "%s/%s-%s-%s.hg" % (backupdir, short(node), totalhash[:8], suffix)

    cgversion = changegroup.safeversion(repo)
    comp = None
    if cgversion != '01':
        bundletype = "HG20"
        if compress:
            comp = 'BZ'
    elif compress:
        bundletype = "HG10BZ"
    else:
        bundletype = "HG10UN"

    outgoing = discovery.outgoing(repo, missingroots=bases, missingheads=heads)
    contentopts = {
        'cg.version': cgversion,
        'obsolescence': obsolescence,
        'phases': True,
    }
    return bundle2.writenewbundle(repo.ui, repo, 'strip', name, bundletype,
                                  outgoing, contentopts, vfs, compression=comp)

def _collectfiles(repo, striprev):
    """find out the filelogs affected by the strip"""
    files = set()

    for x in xrange(striprev, len(repo)):
        files.update(repo[x].files())

    return sorted(files)

def _collectbrokencsets(repo, files, striprev):
    """return the changesets which will be broken by the truncation"""
    s = set()
    def collectone(revlog):
        _, brokenset = revlog.getstrippoint(striprev)
        s.update([revlog.linkrev(r) for r in brokenset])

    collectone(repo.manifestlog._revlog)
    for fname in files:
        collectone(repo.file(fname))

    return s

def strip(ui, repo, nodelist, backup=True, topic='backup'):
    # This function requires the caller to lock the repo, but it operates
    # within a transaction of its own, and thus requires there to be no current
    # transaction when it is called.
    if repo.currenttransaction() is not None:
        raise error.ProgrammingError('cannot strip from inside a transaction')

    # Simple way to maintain backwards compatibility for this
    # argument.
    if backup in ['none', 'strip']:
        backup = False

    repo = repo.unfiltered()
    repo.destroying()

    cl = repo.changelog
    # TODO handle undo of merge sets
    if isinstance(nodelist, str):
        nodelist = [nodelist]
    striplist = [cl.rev(node) for node in nodelist]
    striprev = min(striplist)

    files = _collectfiles(repo, striprev)
    saverevs = _collectbrokencsets(repo, files, striprev)

    # Some revisions with rev > striprev may not be descendants of striprev.
    # We have to find these revisions and put them in a bundle, so that
    # we can restore them after the truncations.
    # To create the bundle we use repo.changegroupsubset which requires
    # the list of heads and bases of the set of interesting revisions.
    # (head = revision in the set that has no descendant in the set;
    #  base = revision in the set that has no ancestor in the set)
    tostrip = set(striplist)
    saveheads = set(saverevs)
    for r in cl.revs(start=striprev + 1):
        if any(p in tostrip for p in cl.parentrevs(r)):
            tostrip.add(r)

        if r not in tostrip:
            saverevs.add(r)
            saveheads.difference_update(cl.parentrevs(r))
            saveheads.add(r)
    saveheads = [cl.node(r) for r in saveheads]

    # compute base nodes
    if saverevs:
        descendants = set(cl.descendants(saverevs))
        saverevs.difference_update(descendants)
    savebases = [cl.node(r) for r in saverevs]
    stripbases = [cl.node(r) for r in tostrip]

    stripobsidx = obsmarkers = ()
    if repo.ui.configbool('devel', 'strip-obsmarkers'):
        obsmarkers = obsutil.exclusivemarkers(repo, stripbases)
    if obsmarkers:
        stripobsidx = [i for i, m in enumerate(repo.obsstore)
                       if m in obsmarkers]

    # For a set s, max(parents(s) - s) is the same as max(heads(::s - s)), but
    # is much faster
    newbmtarget = repo.revs('max(parents(%ld) - (%ld))', tostrip, tostrip)
    if newbmtarget:
        newbmtarget = repo[newbmtarget.first()].node()
    else:
        newbmtarget = '.'

    bm = repo._bookmarks
    updatebm = []
    for m in bm:
        rev = repo[bm[m]].rev()
        if rev in tostrip:
            updatebm.append(m)

    # create a changegroup for all the branches we need to keep
    backupfile = None
    vfs = repo.vfs
    node = nodelist[-1]
    if backup:
        backupfile = _bundle(repo, stripbases, cl.heads(), node, topic)
        repo.ui.status(_("saved backup bundle to %s\n") %
                       vfs.join(backupfile))
        repo.ui.log("backupbundle", "saved backup bundle to %s\n",
                    vfs.join(backupfile))
    tmpbundlefile = None
    if saveheads:
        # do not compress temporary bundle if we remove it from disk later
        #
        # We do not include obsolescence, it might re-introduce prune markers
        # we are trying to strip.  This is harmless since the stripped markers
        # are already backed up and we did not touched the markers for the
        # saved changesets.
        tmpbundlefile = _bundle(repo, savebases, saveheads, node, 'temp',
                                compress=False, obsolescence=False)

    mfst = repo.manifestlog._revlog

    try:
        with repo.transaction("strip") as tr:
            offset = len(tr.entries)

            tr.startgroup()
            cl.strip(striprev, tr)
            mfst.strip(striprev, tr)
            striptrees(repo, tr, striprev, files)

            for fn in files:
                repo.file(fn).strip(striprev, tr)
            tr.endgroup()

            for i in xrange(offset, len(tr.entries)):
                file, troffset, ignore = tr.entries[i]
                with repo.svfs(file, 'a', checkambig=True) as fp:
                    fp.truncate(troffset)
                if troffset == 0:
                    repo.store.markremoved(file)

            deleteobsmarkers(repo.obsstore, stripobsidx)
            del repo.obsstore

        repo._phasecache.filterunknown(repo)
        if tmpbundlefile:
            ui.note(_("adding branch\n"))
            f = vfs.open(tmpbundlefile, "rb")
            gen = exchange.readbundle(ui, f, tmpbundlefile, vfs)
            if not repo.ui.verbose:
                # silence internal shuffling chatter
                repo.ui.pushbuffer()
            tmpbundleurl = 'bundle:' + vfs.join(tmpbundlefile)
            txnname = 'strip'
            if not isinstance(gen, bundle2.unbundle20):
                txnname = "strip\n%s" % util.hidepassword(tmpbundleurl)
            with repo.transaction(txnname) as tr:
                bundle2.applybundle(repo, gen, tr, source='strip',
                                    url=tmpbundleurl)
            if not repo.ui.verbose:
                repo.ui.popbuffer()
            f.close()
        repo._phasecache.invalidate()

        for m in updatebm:
            bm[m] = repo[newbmtarget].node()

        with repo.transaction('repair') as tr:
            bm.recordchange(tr)

        # remove undo files
        for undovfs, undofile in repo.undofiles():
            try:
                undovfs.unlink(undofile)
            except OSError as e:
                if e.errno != errno.ENOENT:
                    ui.warn(_('error removing %s: %s\n') %
                            (undovfs.join(undofile), str(e)))

    except: # re-raises
        if backupfile:
            ui.warn(_("strip failed, backup bundle stored in '%s'\n")
                    % vfs.join(backupfile))
        if tmpbundlefile:
            ui.warn(_("strip failed, unrecovered changes stored in '%s'\n")
                    % vfs.join(tmpbundlefile))
            ui.warn(_("(fix the problem, then recover the changesets with "
                      "\"hg unbundle '%s'\")\n") % vfs.join(tmpbundlefile))
        raise
    else:
        if tmpbundlefile:
            # Remove temporary bundle only if there were no exceptions
            vfs.unlink(tmpbundlefile)

    repo.destroyed()
    # return the backup file path (or None if 'backup' was False) so
    # extensions can use it
    return backupfile

def safestriproots(ui, repo, nodes):
    """return list of roots of nodes where descendants are covered by nodes"""
    torev = repo.unfiltered().changelog.rev
    revs = set(torev(n) for n in nodes)
    # tostrip = wanted - unsafe = wanted - ancestors(orphaned)
    # orphaned = affected - wanted
    # affected = descendants(roots(wanted))
    # wanted = revs
    tostrip = set(repo.revs('%ld-(::((roots(%ld)::)-%ld))', revs, revs, revs))
    notstrip = revs - tostrip
    if notstrip:
        nodestr = ', '.join(sorted(short(repo[n].node()) for n in notstrip))
        ui.warn(_('warning: orphaned descendants detected, '
                  'not stripping %s\n') % nodestr)
    return [c.node() for c in repo.set('roots(%ld)', tostrip)]

class stripcallback(object):
    """used as a transaction postclose callback"""

    def __init__(self, ui, repo, backup, topic):
        self.ui = ui
        self.repo = repo
        self.backup = backup
        self.topic = topic or 'backup'
        self.nodelist = []

    def addnodes(self, nodes):
        self.nodelist.extend(nodes)

    def __call__(self, tr):
        roots = safestriproots(self.ui, self.repo, self.nodelist)
        if roots:
            strip(self.ui, self.repo, roots, self.backup, self.topic)

def delayedstrip(ui, repo, nodelist, topic=None):
    """like strip, but works inside transaction and won't strip irreverent revs

    nodelist must explicitly contain all descendants. Otherwise a warning will
    be printed that some nodes are not stripped.

    Always do a backup. The last non-None "topic" will be used as the backup
    topic name. The default backup topic name is "backup".
    """
    tr = repo.currenttransaction()
    if not tr:
        nodes = safestriproots(ui, repo, nodelist)
        return strip(ui, repo, nodes, True, topic)
    # transaction postclose callbacks are called in alphabet order.
    # use '\xff' as prefix so we are likely to be called last.
    callback = tr.getpostclose('\xffstrip')
    if callback is None:
        callback = stripcallback(ui, repo, True, topic)
        tr.addpostclose('\xffstrip', callback)
    if topic:
        callback.topic = topic
    callback.addnodes(nodelist)

def striptrees(repo, tr, striprev, files):
    if 'treemanifest' in repo.requirements: # safe but unnecessary
                                            # otherwise
        for unencoded, encoded, size in repo.store.datafiles():
            if (unencoded.startswith('meta/') and
                unencoded.endswith('00manifest.i')):
                dir = unencoded[5:-12]
                repo.manifestlog._revlog.dirlog(dir).strip(striprev, tr)

def rebuildfncache(ui, repo):
    """Rebuilds the fncache file from repo history.

    Missing entries will be added. Extra entries will be removed.
    """
    repo = repo.unfiltered()

    if 'fncache' not in repo.requirements:
        ui.warn(_('(not rebuilding fncache because repository does not '
                  'support fncache)\n'))
        return

    with repo.lock():
        fnc = repo.store.fncache
        # Trigger load of fncache.
        if 'irrelevant' in fnc:
            pass

        oldentries = set(fnc.entries)
        newentries = set()
        seenfiles = set()

        repolen = len(repo)
        for rev in repo:
            ui.progress(_('rebuilding'), rev, total=repolen,
                        unit=_('changesets'))

            ctx = repo[rev]
            for f in ctx.files():
                # This is to minimize I/O.
                if f in seenfiles:
                    continue
                seenfiles.add(f)

                i = 'data/%s.i' % f
                d = 'data/%s.d' % f

                if repo.store._exists(i):
                    newentries.add(i)
                if repo.store._exists(d):
                    newentries.add(d)

        ui.progress(_('rebuilding'), None)

        if 'treemanifest' in repo.requirements: # safe but unnecessary otherwise
            for dir in util.dirs(seenfiles):
                i = 'meta/%s/00manifest.i' % dir
                d = 'meta/%s/00manifest.d' % dir

                if repo.store._exists(i):
                    newentries.add(i)
                if repo.store._exists(d):
                    newentries.add(d)

        addcount = len(newentries - oldentries)
        removecount = len(oldentries - newentries)
        for p in sorted(oldentries - newentries):
            ui.write(_('removing %s\n') % p)
        for p in sorted(newentries - oldentries):
            ui.write(_('adding %s\n') % p)

        if addcount or removecount:
            ui.write(_('%d items added, %d removed from fncache\n') %
                     (addcount, removecount))
            fnc.entries = newentries
            fnc._dirty = True

            with repo.transaction('fncache') as tr:
                fnc.write(tr)
        else:
            ui.write(_('fncache already up to date\n'))

def stripbmrevset(repo, mark):
    """
    The revset to strip when strip is called with -B mark

    Needs to live here so extensions can use it and wrap it even when strip is
    not enabled or not present on a box.
    """
    return repo.revs("ancestors(bookmark(%s)) - "
                     "ancestors(head() and not bookmark(%s)) - "
                     "ancestors(bookmark() and not bookmark(%s))",
                     mark, mark, mark)

def deleteobsmarkers(obsstore, indices):
    """Delete some obsmarkers from obsstore and return how many were deleted

    'indices' is a list of ints which are the indices
    of the markers to be deleted.

    Every invocation of this function completely rewrites the obsstore file,
    skipping the markers we want to be removed. The new temporary file is
    created, remaining markers are written there and on .close() this file
    gets atomically renamed to obsstore, thus guaranteeing consistency."""
    if not indices:
        # we don't want to rewrite the obsstore with the same content
        return

    left = []
    current = obsstore._all
    n = 0
    for i, m in enumerate(current):
        if i in indices:
            n += 1
            continue
        left.append(m)

    newobsstorefile = obsstore.svfs('obsstore', 'w', atomictemp=True)
    for bytes in obsolete.encodemarkers(left, True, obsstore._version):
        newobsstorefile.write(bytes)
    newobsstorefile.close()
    return n