view mercurial/unionrepo.py @ 19095:5cc71484ee9c stable

merge: increase safety of parallel updating/removing on icasefs

"merge.applyupdates()" sorts "actions" in removal first order, and
"workeractions" derived from it should be also sorted.

If each actions in "workeractions" are executed in serial, this
sorting ensures that merging/updating process is collision free,
because updating the file in target context is always executed after
removing the existing file which causes case-folding collision against
the former.

In the other hand, if each actions are executed in parallel, updating
on a worker process may be executed before removing on another worker
process, because "worker.partition()" partitions list of actions
regardless of type of each actions.

This patch divides "workeractions" into removing and updating, and
executes the former first.

This patch still scans "actions"/"workeractions" some times for ease
of patch review, even though large list may cost much in this way.
(total cost should be as same as before)

This also changes some tests, because dividing "workeractions" affects
progress indication.

# unionrepo.py - repository class for viewing union of repository changesets
#
# Derived from bundlerepo.py
# Copyright 2006, 2007 Benoit Boissinot <[e-mail]>
# Copyright 2013 Unity Technologies, Mads Kiilerich <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""Repository class for "in-memory pull" of one local repository to another,
allowing operations like diff and log with revsets.
"""

from node import nullid
from i18n import _
import os
import util, mdiff, cmdutil, scmutil
import localrepo, changelog, manifest, filelog, revlog

class unionrevlog(revlog.revlog):
    def __init__(self, opener, indexfile, revlog2, linkmapper):
        # How it works:
        # To retrieve a revision, we just need to know the node id so we can
        # look it up in revlog2.
        #
        # To differentiate a rev in the second revlog from a rev in the revlog,
        # we check revision against repotiprev.
        opener = scmutil.readonlyvfs(opener)
        revlog.revlog.__init__(self, opener, indexfile)
        self.revlog2 = revlog2

        n = len(self)
        self.repotiprev = n - 1
        self.bundlerevs = set() # used by 'bundle()' revset expression
        for rev2 in self.revlog2:
            rev = self.revlog2.index[rev2]
            # rev numbers - in revlog2, very different from self.rev
            _start, _csize, _rsize, _base, linkrev, p1rev, p2rev, node = rev

            if linkmapper is None: # link is to same revlog
                assert linkrev == rev2 # we never link back
                link = n
            else: # rev must be mapped from repo2 cl to unified cl by linkmapper
                link = linkmapper(linkrev)

            if node in self.nodemap:
                # this happens for the common revlog revisions
                self.bundlerevs.add(self.nodemap[node])
                continue

            p1node = self.revlog2.node(p1rev)
            p2node = self.revlog2.node(p2rev)

            e = (None, None, None, None,
                 link, self.rev(p1node), self.rev(p2node), node)
            self.index.insert(-1, e)
            self.nodemap[node] = n
            self.bundlerevs.add(n)
            n += 1

    def _chunk(self, rev):
        if rev <= self.repotiprev:
            return revlog.revlog._chunk(self, rev)
        return self.revlog2._chunk(self.node(rev))

    def revdiff(self, rev1, rev2):
        """return or calculate a delta between two revisions"""
        if rev1 > self.repotiprev and rev2 > self.repotiprev:
            return self.revlog2.revdiff(
                self.revlog2.rev(self.node(rev1)),
                self.revlog2.rev(self.node(rev2)))
        elif rev1 <= self.repotiprev and rev2 <= self.repotiprev:
            return revlog.revlog.revdiff(self, rev1, rev2)

        return mdiff.textdiff(self.revision(self.node(rev1)),
                              self.revision(self.node(rev2)))

    def revision(self, nodeorrev):
        """return an uncompressed revision of a given node or revision
        number.
        """
        if isinstance(nodeorrev, int):
            rev = nodeorrev
            node = self.node(rev)
        else:
            node = nodeorrev
            rev = self.rev(node)

        if node == nullid:
            return ""

        if rev > self.repotiprev:
            text = self.revlog2.revision(node)
            self._cache = (node, rev, text)
        else:
            text = revlog.revlog.revision(self, rev)
            # already cached
        return text

    def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
        raise NotImplementedError
    def addgroup(self, revs, linkmapper, transaction):
        raise NotImplementedError
    def strip(self, rev, minlink):
        raise NotImplementedError
    def checksize(self):
        raise NotImplementedError

class unionchangelog(unionrevlog, changelog.changelog):
    def __init__(self, opener, opener2):
        changelog.changelog.__init__(self, opener)
        linkmapper = None
        changelog2 = changelog.changelog(opener2)
        unionrevlog.__init__(self, opener, self.indexfile, changelog2,
                             linkmapper)

class unionmanifest(unionrevlog, manifest.manifest):
    def __init__(self, opener, opener2, linkmapper):
        manifest.manifest.__init__(self, opener)
        manifest2 = manifest.manifest(opener2)
        unionrevlog.__init__(self, opener, self.indexfile, manifest2,
                             linkmapper)

class unionfilelog(unionrevlog, filelog.filelog):
    def __init__(self, opener, path, opener2, linkmapper, repo):
        filelog.filelog.__init__(self, opener, path)
        filelog2 = filelog.filelog(opener2, path)
        unionrevlog.__init__(self, opener, self.indexfile, filelog2,
                             linkmapper)
        self._repo = repo

    def _file(self, f):
        self._repo.file(f)

class unionpeer(localrepo.localpeer):
    def canpush(self):
        return False

class unionrepository(localrepo.localrepository):
    def __init__(self, ui, path, path2):
        localrepo.localrepository.__init__(self, ui, path)
        self.ui.setconfig('phases', 'publish', False)

        self._url = 'union:%s+%s' % (util.expandpath(path),
                                     util.expandpath(path2))
        self.repo2 = localrepo.localrepository(ui, path2)

    @localrepo.unfilteredpropertycache
    def changelog(self):
        return unionchangelog(self.sopener, self.repo2.sopener)

    def _clrev(self, rev2):
        """map from repo2 changelog rev to temporary rev in self.changelog"""
        node = self.repo2.changelog.node(rev2)
        return self.changelog.rev(node)

    @localrepo.unfilteredpropertycache
    def manifest(self):
        return unionmanifest(self.sopener, self.repo2.sopener,
                             self._clrev)

    def url(self):
        return self._url

    def file(self, f):
        return unionfilelog(self.sopener, f, self.repo2.sopener,
                            self._clrev, self)

    def close(self):
        self.repo2.close()

    def cancopy(self):
        return False

    def peer(self):
        return unionpeer(self)

    def getcwd(self):
        return os.getcwd() # always outside the repo

def instance(ui, path, create):
    if create:
        raise util.Abort(_('cannot create new union repository'))
    parentpath = ui.config("bundle", "mainreporoot", "")
    if not parentpath:
        # try to find the correct path to the working directory repo
        parentpath = cmdutil.findrepo(os.getcwd())
        if parentpath is None:
            parentpath = ''
    if parentpath:
        # Try to make the full path relative so we get a nice, short URL.
        # In particular, we don't want temp dir names in test outputs.
        cwd = os.getcwd()
        if parentpath == cwd:
            parentpath = ''
        else:
            cwd = os.path.join(cwd,'')
            if parentpath.startswith(cwd):
                parentpath = parentpath[len(cwd):]
    if path.startswith('union:'):
        s = path.split(":", 1)[1].split("+", 1)
        if len(s) == 1:
            repopath, repopath2 = parentpath, s[0]
        else:
            repopath, repopath2 = s
    else:
        repopath, repopath2 = parentpath, path
    return unionrepository(ui, repopath, repopath2)