# 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

from .i18n import _

from .node import (

    hex,

    nullrev,

)

from . import (

    bundle2,

    changegroup,

    changelog,

    cmdutil,

    discovery,

    encoding,

    error,

    exchange,

    filelog,

    localrepo,

    manifest,

    mdiff,

    pathutil,

    phases,

    pycompat,

    revlog,

    revlogutils,

    util,

    vfs as vfsmod,

)

from .utils import (

    urlutil,

)

from .revlogutils import (

    constants as revlog_constants,

)

class bundlerevlog(revlog.revlog):

    def __init__(self, opener, target, radix, cgunpacker, 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 = vfsmod.readonlyvfs(opener)

        revlog.revlog.__init__(self, opener, target=target, radix=radix)

        self.bundle = cgunpacker

        n = len(self)

        self.repotiprev = n - 1

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

        for deltadata in cgunpacker.deltaiter():

            node, p1, p2, cs, deltabase, delta, flags, sidedata = deltadata

            size = len(delta)

            start = cgunpacker.tell() - size

            if self.index.has_node(node):

                # this can happen if two branches make the same change

                self.bundlerevs.add(self.index.rev(node))

                continue

            if cs == node:

                linkrev = nullrev

            else:

                linkrev = linkmapper(cs)

            for p in (p1, p2):

                if not self.index.has_node(p):

                    raise error.LookupError(

                        p, self.display_id, _(b"unknown parent")

                    )

            if not self.index.has_node(deltabase):

                raise LookupError(

                    deltabase, self.display_id, _(b'unknown delta base')

                )

            baserev = self.rev(deltabase)

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

            e = revlogutils.entry(

                flags=flags,

                data_offset=start,

                data_compressed_length=size,

                data_delta_base=baserev,

                link_rev=linkrev,

                parent_rev_1=self.rev(p1),

                parent_rev_2=self.rev(p2),

                node_id=node,

            )

            self.index.append(e)

            self.bundlerevs.add(n)

            n += 1

    def _chunk(self, rev, df=None):

        # 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.rawdata(rev1), self.rawdata(rev2))

    def _rawtext(self, node, rev, _df=None):

        if rev is None:

            rev = self.rev(node)

        validated = False

        rawtext = None

        chain = []

        iterrev = rev

        # reconstruct the revision if it is from a changegroup

        while iterrev > self.repotiprev:

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

                rawtext = self._revisioncache[2]

                break

            chain.append(iterrev)

            iterrev = self.index[iterrev][3]

        if iterrev == nullrev:

            rawtext = b''

        elif rawtext is None:

            r = super(bundlerevlog, self)._rawtext(

                self.node(iterrev), iterrev, _df=_df

            )

            __, rawtext, validated = r

        if chain:

            validated = False

        while chain:

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

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

        return rev, rawtext, validated

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

        raise NotImplementedError

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

        raise NotImplementedError

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

        raise NotImplementedError

    def checksize(self):

        raise NotImplementedError

class bundlechangelog(bundlerevlog, changelog.changelog):

    def __init__(self, opener, cgunpacker):

        changelog.changelog.__init__(self, opener)

        linkmapper = lambda x: x

        bundlerevlog.__init__(

            self,

            opener,

            (revlog_constants.KIND_CHANGELOG, None),

            self.radix,

            cgunpacker,

            linkmapper,

        )

class bundlemanifest(bundlerevlog, manifest.manifestrevlog):

    def __init__(

        self,

        nodeconstants,

        opener,

        cgunpacker,

        linkmapper,

        dirlogstarts=None,

        dir=b'',

    ):

        manifest.manifestrevlog.__init__(self, nodeconstants, opener, tree=dir)

        bundlerevlog.__init__(

            self,

            opener,

            (revlog_constants.KIND_MANIFESTLOG, dir),

            self._revlog.radix,

            cgunpacker,

            linkmapper,

        )

        if dirlogstarts is None:

            dirlogstarts = {}

            if self.bundle.version == b"03":

                dirlogstarts = _getfilestarts(self.bundle)

        self._dirlogstarts = dirlogstarts

        self._linkmapper = linkmapper

    def dirlog(self, d):

        if d in self._dirlogstarts:

            self.bundle.seek(self._dirlogstarts[d])

            return bundlemanifest(

                self.nodeconstants,

                self.opener,

                self.bundle,

                self._linkmapper,

                self._dirlogstarts,

                dir=d,

            )

        return super(bundlemanifest, self).dirlog(d)

class bundlefilelog(filelog.filelog):

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

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

        self._revlog = bundlerevlog(

            opener,

            # XXX should use the unencoded path

            target=(revlog_constants.KIND_FILELOG, path),

            radix=self._revlog.radix,

            cgunpacker=cgunpacker,

            linkmapper=linkmapper,

        )

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 = vfsmod.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

def _getfilestarts(cgunpacker):

    filespos = {}

    for chunkdata in iter(cgunpacker.filelogheader, {}):

        fname = chunkdata[b'filename']

        filespos[fname] = cgunpacker.tell()

        for chunk in iter(lambda: cgunpacker.deltachunk(None), {}):

            pass

    return filespos

class bundlerepository(object):

    """A repository instance that is a union of a local repo and a bundle.

    Instances represent a read-only repository composed of a local repository

    with the contents of a bundle file applied. The repository instance is

    conceptually similar to the state of a repository after an

    ``hg unbundle`` operation. However, the contents of the bundle are never

    applied to the actual base repository.

    Instances constructed directly are not usable as repository objects.

    Use instance() or makebundlerepository() to create instances.

    """

    def __init__(self, bundlepath, url, tempparent):

        self._tempparent = tempparent

        self._url = url

        self.ui.setconfig(b'phases', b'publish', False, b'bundlerepo')

        self.tempfile = None

        f = util.posixfile(bundlepath, b"rb")

        bundle = exchange.readbundle(self.ui, f, bundlepath)

        if isinstance(bundle, bundle2.unbundle20):

            self._bundlefile = bundle

            self._cgunpacker = None

            cgpart = None

            for part in bundle.iterparts(seekable=True):

                if part.type == b'changegroup':

                    if cgpart:

                        raise NotImplementedError(

                            b"can't process multiple changegroups"

                        )

                    cgpart = part

                self._handlebundle2part(bundle, part)

            if not cgpart:

                raise error.Abort(_(b"No changegroups found"))

            # This is required to placate a later consumer, which expects

            # the payload offset to be at the beginning of the changegroup.

            # We need to do this after the iterparts() generator advances

            # because iterparts() will seek to end of payload after the

            # generator returns control to iterparts().

            cgpart.seek(0, os.SEEK_SET)

        elif isinstance(bundle, changegroup.cg1unpacker):

            if bundle.compressed():

                f = self._writetempbundle(

                    bundle.read, b'.hg10un', header=b'HG10UN'

                )

                bundle = exchange.readbundle(self.ui, f, bundlepath, self.vfs)

            self._bundlefile = bundle

            self._cgunpacker = bundle

        else:

            raise error.Abort(

                _(b'bundle type %s cannot be read') % type(bundle)

            )

        # dict with the mapping 'filename' -> position in the changegroup.

        self._cgfilespos = {}

        self.firstnewrev = self.changelog.repotiprev + 1

        phases.retractboundary(

            self,

            None,

            phases.draft,

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

        )

    def _handlebundle2part(self, bundle, part):

        if part.type != b'changegroup':

            return

        cgstream = part

        version = part.params.get(b'version', b'01')

        legalcgvers = changegroup.supportedincomingversions(self)

        if version not in legalcgvers:

            msg = _(b'Unsupported changegroup version: %s')

            raise error.Abort(msg % version)

        if bundle.compressed():

            cgstream = self._writetempbundle(part.read, b'.cg%sun' % version)

        self._cgunpacker = changegroup.getunbundler(version, cgstream, b'UN')

    def _writetempbundle(self, readfn, suffix, header=b''):

        """Write a temporary file to disk"""

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

        self.tempfile = temp

        with os.fdopen(fdtemp, 'wb') as fptemp:

            fptemp.write(header)

            while True:

                chunk = readfn(2 ** 18)

                if not chunk:

                    break

                fptemp.write(chunk)

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