# bundlerepo.py - repository class for viewing uncompressed bundles

#

# Copyright 2006, 2007 Benoit Boissinot <bboissin@gmail.com>

#

# 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 __future__ import absolute_import

import os

import shutil

import tempfile

from .i18n import _

from .node import nullid

from . import (

    bundle2,

    changegroup,

    changelog,

    cmdutil,

    discovery,

    error,

    exchange,

    filelog,

    localrepo,

    manifest,

    mdiff,

    pathutil,

    phases,

    revlog,

    scmutil,

    util,

)

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). The base of the delta is stored in the base field.

        #

        # To differentiate a rev in the bundle from a rev in the revlog, we

        # check revision against repotiprev.

        opener = scmutil.readonlyvfs(opener)

        revlog.revlog.__init__(self, opener, indexfile)

        self.bundle = bundle

        n = len(self)

        self.repotiprev = n - 1

        chain = None

        self.bundlerevs = set() # used by 'bundle()' revset expression

        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)

            if node in self.nodemap:

                # this can happen if two branches make the same change

                chain = node

                self.bundlerevs.add(self.nodemap[node])

                continue

            for p in (p1, p2):

                if p not in self.nodemap:

                    raise error.LookupError(p, self.indexfile,

                                            _("unknown parent"))

            if deltabase not in self.nodemap:

                raise LookupError(deltabase, self.indexfile,

                                  _('unknown delta base'))

            baserev = self.rev(deltabase)

            # start, size, full unc. size, base (unused), link, p1, p2, node

            e = (revlog.offset_type(start, 0), size, -1, baserev, link,

                 self.rev(p1), self.rev(p2), node)

            self.index.insert(-1, e)

            self.nodemap[node] = n

            self.bundlerevs.add(n)

            chain = node

            n += 1

    def _chunk(self, rev):

        # Warning: in case of bundle, the diff is against what we stored as

        # delta base, not against rev - 1

        # XXX: could use some caching

        if rev <= self.repotiprev:

            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 rev1 > self.repotiprev and rev2 > self.repotiprev:

            # hot path for bundle

            revb = self.index[rev2][3]

            if revb == rev1:

                return self._chunk(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 ""

        text = None

        chain = []

        iterrev = rev

        # reconstruct the revision if it is from a changegroup

        while iterrev > self.repotiprev:

            if self._cache and self._cache[1] == iterrev:

                text = self._cache[2]

                break

            chain.append(iterrev)

            iterrev = self.index[iterrev][3]

        if text is None:

            text = self.baserevision(iterrev)

        while chain:

            delta = self._chunk(chain.pop())

            text = mdiff.patches(text, [delta])

        self._checkhash(text, node, rev)

        self._cache = (node, rev, text)

        return text

    def baserevision(self, nodeorrev):

        # Revlog subclasses may override 'revision' method to modify format of

        # content retrieved from revlog. To use bundlerevlog with such class one

        # needs to override 'baserevision' and make more specific call here.

        return revlog.revlog.revision(self, nodeorrev)

    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)

    def baserevision(self, nodeorrev):

        # Although changelog doesn't override 'revision' method, some extensions

        # may replace this class with another that does. Same story with

        # manifest and filelog classes.

        # This bypasses filtering on changelog.node() and rev() because we need

        # revision text of the bundle base even if it is hidden.

        oldfilter = self.filteredrevs

        try:

            self.filteredrevs = ()

            return changelog.changelog.revision(self, nodeorrev)

        finally:

            self.filteredrevs = oldfilter

class bundlemanifest(bundlerevlog, manifest.manifest):

    def __init__(self, opener, bundle, linkmapper):

        manifest.manifest.__init__(self, opener)

        bundlerevlog.__init__(self, opener, self.indexfile, bundle,

                              linkmapper)

    def baserevision(self, nodeorrev):

        node = nodeorrev

        if isinstance(node, int):

            node = self.node(node)

        if node in self._mancache:

            result = self._mancache[node][0].text()

        else:

            result = manifest.manifest.revision(self, nodeorrev)

        return result

class bundlefilelog(bundlerevlog, filelog.filelog):

    def __init__(self, opener, path, bundle, linkmapper):

        filelog.filelog.__init__(self, opener, path)

        bundlerevlog.__init__(self, opener, self.indexfile, bundle,

                              linkmapper)

    def baserevision(self, nodeorrev):

        return filelog.filelog.revision(self, nodeorrev)

class bundlepeer(localrepo.localpeer):

    def canpush(self):

        return False

class bundlephasecache(phases.phasecache):

    def __init__(self, *args, **kwargs):

        super(bundlephasecache, self).__init__(*args, **kwargs)

        if util.safehasattr(self, 'opener'):

            self.opener = scmutil.readonlyvfs(self.opener)

    def write(self):

        raise NotImplementedError

    def _write(self, fp):

        raise NotImplementedError

    def _updateroots(self, phase, newroots, tr):

        self.phaseroots[phase] = newroots

        self.invalidate()

        self.dirty = True

class bundlerepository(localrepo.localrepository):

    def __init__(self, ui, path, bundlename):

        def _writetempbundle(read, suffix, header=''):

            """Write a temporary file to disk

            This is closure because we need to make sure this tracked by

            self.tempfile for cleanup purposes."""

            fdtemp, temp = self.vfs.mkstemp(prefix="hg-bundle-",

                                            suffix=".hg10un")

            self.tempfile = temp

            fptemp = os.fdopen(fdtemp, 'wb')

            try:

                fptemp.write(header)

                while True:

                    chunk = read(2**18)

                    if not chunk:

                        break

                    fptemp.write(chunk)

            finally:

                fptemp.close()

            return self.vfs.open(self.tempfile, mode="rb")

        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, 'bundlerepo')

        if path:

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

        else:

            self._url = 'bundle:' + bundlename

        self.tempfile = None

        f = util.posixfile(bundlename, "rb")

        self.bundlefile = self.bundle = exchange.readbundle(ui, f, bundlename)

        if isinstance(self.bundle, bundle2.unbundle20):

            cgparts = [part for part in self.bundle.iterparts()

                       if (part.type == 'changegroup')

                       and (part.params.get('version', '01')

                            in changegroup.packermap)]

            if not cgparts:

                raise error.Abort('No changegroups found')

            version = cgparts[0].params.get('version', '01')

            cgparts = [p for p in cgparts

                       if p.params.get('version', '01') == version]

            if len(cgparts) > 1:

                raise NotImplementedError("Can't process multiple changegroups")

            part = cgparts[0]

            part.seek(0)

            self.bundle = changegroup.packermap[version][1](part, 'UN')

        # dict with the mapping 'filename' -> position in the bundle

        self.bundlefilespos = {}

        self.firstnewrev = self.changelog.repotiprev + 1

        phases.retractboundary(self, None, phases.draft,

                               [ctx.node() for ctx in self[self.firstnewrev:]])

    @localrepo.unfilteredpropertycache

    def _phasecache(self):

        return bundlephasecache(self, self._phasedefaults)

    @localrepo.unfilteredpropertycache

    def changelog(self):

        # consume the header if it exists

        self.bundle.changelogheader()

        c = bundlechangelog(self.svfs, 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.svfs, 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 in self.bundlefilespos:

            self.bundle.seek(self.bundlefilespos[f])

            return bundlefilelog(self.svfs, f, self.bundle, self.changelog.rev)

        else:

            return filelog.filelog(self.svfs, f)

    def close(self):

        """Close assigned bundle file immediately."""

        self.bundlefile.close()

        if self.tempfile is not None:

            self.vfs.unlink(self.tempfile)