mercurial/bundlerepo.py

bundlerepo: enforce reading from core repo only

We do not want anything computed with the bundle overlay to be written back in
the repo. Such write will likely contains invalid data.

The short terms goal of this change is to drop use of `_cacheabletip` in bundle
repo.

# bundlerepo.py - repository class for viewing uncompressed bundles
#
# Copyright 2006, 2007 Benoit Boissinot <[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 viewing uncompressed bundles.

This provides a read-only repository interface to bundles as if they
were part of the actual repository.
"""

from node import nullid
from i18n import _
import os, tempfile, shutil
import changegroup, util, mdiff, discovery, cmdutil, scmutil
import localrepo, changelog, manifest, filelog, revlog, error

class bundlerevlog(revlog.revlog):
    def __init__(self, opener, indexfile, bundle, linkmapper):
        # How it works:
        # to retrieve a revision, we need to know the offset of
        # the revision in the bundle (an unbundle object).
        #
        # We store this offset in the index (start), to differentiate a
        # rev in the bundle and from a rev in the revlog, we check
        # len(index[r]). If the tuple is bigger than 7, it is a bundle
        # (it is bigger since we store the node to which the delta is)
        #
        opener = scmutil.readonlyvfs(opener)
        revlog.revlog.__init__(self, opener, indexfile)
        self.bundle = bundle
        self.basemap = {}
        n = len(self)
        self.disktiprev = n - 1
        chain = None
        self.bundlenodes = []
        while True:
            chunkdata = bundle.deltachunk(chain)
            if not chunkdata:
                break
            node = chunkdata['node']
            p1 = chunkdata['p1']
            p2 = chunkdata['p2']
            cs = chunkdata['cs']
            deltabase = chunkdata['deltabase']
            delta = chunkdata['delta']

            size = len(delta)
            start = bundle.tell() - size

            link = linkmapper(cs)
            self.bundlenodes.append(node)
            if node in self.nodemap:
                # this can happen if two branches make the same change
                chain = node
                continue

            for p in (p1, p2):
                if p not in self.nodemap:
                    raise error.LookupError(p, self.indexfile,
                                            _("unknown parent"))
            # start, size, full unc. size, base (unused), link, p1, p2, node
            e = (revlog.offset_type(start, 0), size, -1, -1, link,
                 self.rev(p1), self.rev(p2), node)
            self.basemap[n] = deltabase
            self.index.insert(-1, e)
            self.nodemap[node] = n
            chain = node
            n += 1

    def inbundle(self, rev):
        """is rev from the bundle"""
        if rev < 0:
            return False
        return rev in self.basemap
    def bundlebase(self, rev):
        return self.basemap[rev]
    def _chunk(self, rev):
        # Warning: in case of bundle, the diff is against bundlebase,
        # not against rev - 1
        # XXX: could use some caching
        if not self.inbundle(rev):
            return revlog.revlog._chunk(self, rev)
        self.bundle.seek(self.start(rev))
        return self.bundle.read(self.length(rev))

    def revdiff(self, rev1, rev2):
        """return or calculate a delta between two revisions"""
        if self.inbundle(rev1) and self.inbundle(rev2):
            # hot path for bundle
            revb = self.rev(self.bundlebase(rev2))
            if revb == rev1:
                return self._chunk(rev2)
        elif not self.inbundle(rev1) and not self.inbundle(rev2):
            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 ""

        text = None
        chain = []
        iter_node = node
        # reconstruct the revision if it is from a changegroup
        while self.inbundle(rev):
            if self._cache and self._cache[0] == iter_node:
                text = self._cache[2]
                break
            chain.append(rev)
            iter_node = self.bundlebase(rev)
            rev = self.rev(iter_node)
        if text is None:
            text = revlog.revlog.revision(self, iter_node)

        while chain:
            delta = self._chunk(chain.pop())
            text = mdiff.patches(text, [delta])

        p1, p2 = self.parents(node)
        if node != revlog.hash(text, p1, p2):
            raise error.RevlogError(_("integrity check failed on %s:%d")
                                     % (self.datafile, self.rev(node)))

        self._cache = (node, self.rev(node), text)
        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 bundlechangelog(bundlerevlog, changelog.changelog):
    def __init__(self, opener, bundle):
        changelog.changelog.__init__(self, opener)
        linkmapper = lambda x: x
        bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                              linkmapper)

class bundlemanifest(bundlerevlog, manifest.manifest):
    def __init__(self, opener, bundle, linkmapper):
        manifest.manifest.__init__(self, opener)
        bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                              linkmapper)

class bundlefilelog(bundlerevlog, filelog.filelog):
    def __init__(self, opener, path, bundle, linkmapper, repo):
        filelog.filelog.__init__(self, opener, path)
        bundlerevlog.__init__(self, opener, self.indexfile, bundle,
                              linkmapper)
        self._repo = repo

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

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

class bundlerepository(localrepo.localrepository):
    def __init__(self, ui, path, bundlename):
        self._tempparent = None
        try:
            localrepo.localrepository.__init__(self, ui, path)
        except error.RepoError:
            self._tempparent = tempfile.mkdtemp()
            localrepo.instance(ui, self._tempparent, 1)
            localrepo.localrepository.__init__(self, ui, self._tempparent)
        self.ui.setconfig('phases', 'publish', False)

        if path:
            self._url = 'bundle:' + util.expandpath(path) + '+' + bundlename
        else:
            self._url = 'bundle:' + bundlename

        self.tempfile = None
        f = util.posixfile(bundlename, "rb")
        self.bundle = changegroup.readbundle(f, bundlename)
        if self.bundle.compressed():
            fdtemp, temp = tempfile.mkstemp(prefix="hg-bundle-",
                                            suffix=".hg10un", dir=self.path)
            self.tempfile = temp
            fptemp = os.fdopen(fdtemp, 'wb')

            try:
                fptemp.write("HG10UN")
                while True:
                    chunk = self.bundle.read(2**18)
                    if not chunk:
                        break
                    fptemp.write(chunk)
            finally:
                fptemp.close()

            f = util.posixfile(self.tempfile, "rb")
            self.bundle = changegroup.readbundle(f, bundlename)

        # dict with the mapping 'filename' -> position in the bundle
        self.bundlefilespos = {}

    @localrepo.unfilteredpropertycache
    def changelog(self):
        # consume the header if it exists
        self.bundle.changelogheader()
        c = bundlechangelog(self.sopener, self.bundle)
        self.manstart = self.bundle.tell()
        return c

    @localrepo.unfilteredpropertycache
    def manifest(self):
        self.bundle.seek(self.manstart)
        # consume the header if it exists
        self.bundle.manifestheader()
        m = bundlemanifest(self.sopener, self.bundle, self.changelog.rev)
        self.filestart = self.bundle.tell()
        return m

    @localrepo.unfilteredpropertycache
    def manstart(self):
        self.changelog
        return self.manstart

    @localrepo.unfilteredpropertycache
    def filestart(self):
        self.manifest
        return self.filestart

    def url(self):
        return self._url

    def file(self, f):
        if not self.bundlefilespos:
            self.bundle.seek(self.filestart)
            while True:
                chunkdata = self.bundle.filelogheader()
                if not chunkdata:
                    break
                fname = chunkdata['filename']
                self.bundlefilespos[fname] = self.bundle.tell()
                while True:
                    c = self.bundle.deltachunk(None)
                    if not c:
                        break

        if f[0] == '/':
            f = f[1:]
        if f in self.bundlefilespos:
            self.bundle.seek(self.bundlefilespos[f])
            return bundlefilelog(self.sopener, f, self.bundle,
                                 self.changelog.rev, self)
        else:
            return filelog.filelog(self.sopener, f)

    def close(self):
        """Close assigned bundle file immediately."""
        self.bundle.close()
        if self.tempfile is not None:
            os.unlink(self.tempfile)
        if self._tempparent:
            shutil.rmtree(self._tempparent, True)

    def cancopy(self):
        return False

    def peer(self):
        return bundlepeer(self)

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

    def _cacheabletip(self):
        # we should not cache data from the bundle on disk
        ret = super(bundlerepository, self)._cacheabletip()
        return min(self.changelog.disktiprev, ret)


def instance(ui, path, create):
    if create:
        raise util.Abort(_('cannot create new bundle 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):]
    u = util.url(path)
    path = u.localpath()
    if u.scheme == 'bundle':
        s = path.split("+", 1)
        if len(s) == 1:
            repopath, bundlename = parentpath, s[0]
        else:
            repopath, bundlename = s
    else:
        repopath, bundlename = parentpath, path
    return bundlerepository(ui, repopath, bundlename)

def getremotechanges(ui, repo, other, onlyheads=None, bundlename=None,
                     force=False):
    '''obtains a bundle of changes incoming from other

    "onlyheads" restricts the returned changes to those reachable from the
      specified heads.
    "bundlename", if given, stores the bundle to this file path permanently;
      otherwise it's stored to a temp file and gets deleted again when you call
      the returned "cleanupfn".
    "force" indicates whether to proceed on unrelated repos.

    Returns a tuple (local, csets, cleanupfn):

    "local" is a local repo from which to obtain the actual incoming
      changesets; it is a bundlerepo for the obtained bundle when the
      original "other" is remote.
    "csets" lists the incoming changeset node ids.
    "cleanupfn" must be called without arguments when you're done processing
      the changes; it closes both the original "other" and the one returned
      here.
    '''
    tmp = discovery.findcommonincoming(repo, other, heads=onlyheads,
                                       force=force)
    common, incoming, rheads = tmp
    if not incoming:
        try:
            if bundlename:
                os.unlink(bundlename)
        except OSError:
            pass
        return repo, [], other.close

    bundle = None
    bundlerepo = None
    localrepo = other.local()
    if bundlename or not localrepo:
        # create a bundle (uncompressed if other repo is not local)

        if other.capable('getbundle'):
            cg = other.getbundle('incoming', common=common, heads=rheads)
        elif onlyheads is None and not other.capable('changegroupsubset'):
            # compat with older servers when pulling all remote heads
            cg = other.changegroup(incoming, "incoming")
            rheads = None
        else:
            cg = other.changegroupsubset(incoming, rheads, 'incoming')
        bundletype = localrepo and "HG10BZ" or "HG10UN"
        fname = bundle = changegroup.writebundle(cg, bundlename, bundletype)
        # keep written bundle?
        if bundlename:
            bundle = None
        if not localrepo:
            # use the created uncompressed bundlerepo
            localrepo = bundlerepo = bundlerepository(ui, repo.root, fname)
            # this repo contains local and other now, so filter out local again
            common = repo.heads()

    csets = localrepo.changelog.findmissing(common, rheads)

    def cleanup():
        if bundlerepo:
            bundlerepo.close()
        if bundle:
            os.unlink(bundle)
        other.close()

    return (localrepo, csets, cleanup)