~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2007 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

from __future__ import absolute_import

from bzrlib import errors

def _load_data_py(kndx, fp):

    """Read in a knit index."""

    cache = kndx._cache

    history = kndx._history

    kndx.check_header(fp)

    # readlines reads the whole file at once:

    # bad for transports like http, good for local disk

    # we save 60 ms doing this one change (

    # from calling readline each time to calling

    # readlines once.

    # probably what we want for nice behaviour on

    # http is a incremental readlines that yields, or

    # a check for local vs non local indexes,

    history_top = len(history) - 1

    for line in fp.readlines():

        rec = line.split()

        if len(rec) < 5 or rec[-1] != ':':

            # corrupt line.

            # FIXME: in the future we should determine if its a

            # short write - and ignore it

            # or a different failure, and raise. RBC 20060407

            continue

        try:

            parents = []

            for value in rec[4:-1]:

                if value[0] == '.':

                    # uncompressed reference

                    parent_id = value[1:]

                else:

                    parent_id = history[int(value)]

                parents.append(parent_id)

        except (IndexError, ValueError), e:

            # The parent could not be decoded to get its parent row. This

            # at a minimum will cause this row to have wrong parents, or

            # even to apply a delta to the wrong base and decode

            # incorrectly. its therefore not usable, and because we have

            # encountered a situation where a new knit index had this

            # corrupt we can't asssume that no other rows referring to the

            # index of this record actually mean the subsequent uncorrupt

            # one, so we error.

            raise errors.KnitCorrupt(kndx._filename, "line %r: %s" % (rec, e))

        version_id, options, pos, size = rec[:4]

        version_id = version_id

        try:

            pos = int(pos)

        except ValueError, e:

            raise errors.KnitCorrupt(kndx._filename,

                                     "invalid position on line %r: %s"

                                     % (rec, e))

        try:

            size = int(size)

        except ValueError, e:

            raise errors.KnitCorrupt(kndx._filename,

                                     "invalid size on line %r: %s"

                                     % (rec, e))

        # See kndx._cache_version

        # only want the _history index to reference the 1st

        # index entry for version_id

        if version_id not in cache:

            history_top += 1

            index = history_top

            history.append(version_id)

        else:

            index = cache[version_id][5]

        cache[version_id] = (version_id,

                             options.split(','),

                             pos,

                             size,

                             tuple(parents),

                             index)

        # end kndx._cache_version