~bzr-pqm/bzr/bzr.dev

# (C) 2005 Canonical Development 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Serializer factory for reading and writing bundles.

"""

import base64

from StringIO import StringIO

import re

import bzrlib.errors as errors

from bzrlib.diff import internal_diff

from bzrlib.revision import NULL_REVISION

# New bundles should try to use this header format

BUNDLE_HEADER = '# Bazaar revision bundle v'

BUNDLE_HEADER_RE = re.compile(r'^# Bazaar revision bundle v(?P<version>\d+[\w.]*)\n$')

CHANGESET_OLD_HEADER_RE = re.compile(r'^# Bazaar-NG changeset v(?P<version>\d+[\w.]*)\n$')

_serializers = {} 

def _get_filename(f):

    if hasattr(f, 'name'):

        return f.name

    return '<unknown>'

def read_bundle(f):

    """Read in a bundle from a filelike object.

    :param f: A file-like object

    :return: A list of Bundle objects

    """

    version = None

    for line in f:

        m = BUNDLE_HEADER_RE.match(line)

        if m:

            version = m.group('version')

            break

        elif line.startswith(BUNDLE_HEADER):

            raise errors.MalformedHeader()

        m = CHANGESET_OLD_HEADER_RE.match(line)

        if m:

            version = m.group('version')

            raise errors.BundleNotSupported(version, 'old format bundles not supported')

    if version is None:

        raise errors.NotABundle('Did not find an opening header')

    # Now we have a version, to figure out how to read the bundle 

    if not _serializers.has_key(version):

        raise errors.BundleNotSupported(version, 'version not listed in known versions')

    serializer = _serializers[version](version)

    return serializer.read(f)

def write(source, revision_ids, f, version=None, forced_bases={}):

    """Serialize a list of bundles to a filelike object.

    :param source: A source for revision information

    :param revision_ids: The list of revision ids to serialize

    :param f: The file to output to

    :param version: [optional] target serialization version

    """

    if not _serializers.has_key(version):

        raise errors.BundleNotSupported(version, 'unknown bundle format')

    serializer = _serializers[version](version)

    return serializer.write(source, revision_ids, forced_bases, f) 

def write_bundle(repository, revision_id, base_revision_id, out):

    """"""

    if base_revision_id is NULL_REVISION:

        base_revision_id = None

    base_ancestry = set(repository.get_ancestry(base_revision_id))

    revision_ids = [r for r in repository.get_ancestry(revision_id) if r

                    not in base_ancestry]

    revision_ids = list(reversed(revision_ids))

    write(repository, revision_ids, out, 

          forced_bases = {revision_id:base_revision_id})

    return revision_ids

def format_highres_date(t, offset=0):

    """Format a date, such that it includes higher precision in the

    seconds field.

    :param t:   The local time in fractional seconds since the epoch

    :type t: float

    :param offset:  The timezone offset in integer seconds

    :type offset: int

    Example: format_highres_date(time.time(), -time.timezone)

    this will return a date stamp for right now,

    formatted for the local timezone.

    >>> from bzrlib.osutils import format_date

    >>> format_date(1120153132.350850105, 0)

    'Thu 2005-06-30 17:38:52 +0000'

    >>> format_highres_date(1120153132.350850105, 0)

    'Thu 2005-06-30 17:38:52.350850105 +0000'

    >>> format_date(1120153132.350850105, -5*3600)

    'Thu 2005-06-30 12:38:52 -0500'

    >>> format_highres_date(1120153132.350850105, -5*3600)

    'Thu 2005-06-30 12:38:52.350850105 -0500'

    >>> format_highres_date(1120153132.350850105, 7200)

    'Thu 2005-06-30 19:38:52.350850105 +0200'

    """

    import time

    assert isinstance(t, float)

    # This has to be formatted for "original" date, so that the

    # revision XML entry will be reproduced faithfully.

    if offset == None:

        offset = 0

    tt = time.gmtime(t + offset)

    return (time.strftime("%a %Y-%m-%d %H:%M:%S", tt)

            + ('%.9f' % (t - int(t)))[1:] # Get the high-res seconds, but ignore the 0

            + ' %+03d%02d' % (offset / 3600, (offset / 60) % 60))

def unpack_highres_date(date):

    """This takes the high-resolution date stamp, and

    converts it back into the tuple (timestamp, timezone)

    Where timestamp is in real UTC since epoch seconds, and timezone is an integer

    number of seconds offset.

    :param date: A date formated by format_highres_date

    :type date: string

    >>> import time, random

    >>> unpack_highres_date('Thu 2005-06-30 12:38:52.350850105 -0500')

    (1120153132.3508501, -18000)

    >>> unpack_highres_date('Thu 2005-06-30 17:38:52.350850105 +0000')

    (1120153132.3508501, 0)

    >>> unpack_highres_date('Thu 2005-06-30 19:38:52.350850105 +0200')

    (1120153132.3508501, 7200)

    >>> from bzrlib.osutils import local_time_offset

    >>> t = time.time()

    >>> o = local_time_offset()

    >>> t2, o2 = unpack_highres_date(format_highres_date(t, o))

    >>> t == t2

    True

    >>> o == o2

    True

    >>> t -= 24*3600*365*2 # Start 2 years ago

    >>> o = -12*3600

    >>> for count in xrange(500):

    ...   t += random.random()*24*3600*30

    ...   o = ((o/3600 + 13) % 25 - 12)*3600 # Add 1 wrap around from [-12, 12]

    ...   date = format_highres_date(t, o)

    ...   t2, o2 = unpack_highres_date(date)

    ...   if t != t2 or o != o2:

    ...      print 'Failed on date %r, %s,%s diff:%s' % (date, t, o, t2-t)

    ...      break

    """

    import time, calendar

    # Up until the first period is a datestamp that is generated

    # as normal from time.strftime, so use time.strptime to

    # parse it

    dot_loc = date.find('.')

    if dot_loc == -1:

        raise ValueError('Date string does not contain high-precision seconds: %r' % date)

    base_time = time.strptime(date[:dot_loc], "%a %Y-%m-%d %H:%M:%S")

    fract_seconds, offset = date[dot_loc:].split()

    fract_seconds = float(fract_seconds)

    offset = int(offset)

    offset = int(offset / 100) * 3600 + offset % 100

    # time.mktime returns localtime, but calendar.timegm returns UTC time

    timestamp = calendar.timegm(base_time)

    timestamp -= offset

    # Add back in the fractional seconds

    timestamp += fract_seconds

    return (timestamp, offset)

class BundleSerializer(object):

    """The base class for Serializers.

    Common functionality should be included here.

    """

    def __init__(self, version):

        self.version = version

    def read(self, f):

        """Read the rest of the bundles from the supplied file.

        :param f: The file to read from

        :return: A list of bundle trees

        """

        raise NotImplementedError

    def write(self, source, revision_ids, forced_bases, f):

        """Write the bundle to the supplied file.

        :param source: A source for revision information

        :param revision_ids: The list of revision ids to serialize

        :param forced_bases: A dict of revision -> base that overrides default

        :param f: The file to output to

        """

        raise NotImplementedError

def register(version, klass, overwrite=False):

    """Register a BundleSerializer version.

    :param version: The version associated with this format

    :param klass: The class to instantiate, which must take a version argument

    """

    global _serializers

    if overwrite:

        _serializers[version] = klass

        return

    if not _serializers.has_key(version):

        _serializers[version] = klass

def register_lazy(version, module, classname, overwrite=False):

    """Register lazy-loaded bundle serializer.

    :param version: The version associated with this reader

    :param module: String indicating what module should be loaded

    :param classname: Name of the class that will be instantiated

    :param overwrite: Should this version override a default

    """

    def _loader(version):

        mod = __import__(module, globals(), locals(), [classname])

        klass = getattr(mod, classname)

        return klass(version)

    register(version, _loader, overwrite=overwrite)

def binary_diff(old_filename, old_lines, new_filename, new_lines, to_file):

    temp = StringIO()

    internal_diff(old_filename, old_lines, new_filename, new_lines, temp,

                  allow_binary=True)

    temp.seek(0)

    base64.encode(temp, to_file)

    to_file.write('\n')

register_lazy('0.8', 'bzrlib.bundle.serializer.v08', 'BundleSerializerV08')

register_lazy(None, 'bzrlib.bundle.serializer.v08', 'BundleSerializerV08')