~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2008 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

"""Serializer object for CHK based inventory storage."""

from cStringIO import (

    StringIO,

    )

from bzrlib import (

    bencode,

    cache_utf8,

    inventory,

    osutils,

    revision as _mod_revision,

    xml5,

    xml6,

    )

def _validate_properties(props, _decode=cache_utf8._utf8_decode):

    # TODO: we really want an 'isascii' check for key

    # Cast the utf8 properties into Unicode 'in place'

    for key, value in props.iteritems():

        props[key] = _decode(value)[0]

    return props

def _is_format_10(value):

    if value != 10:

        raise ValueError('Format number was not recognized, expected 10 got %d'

                         % (value,))

    return 10

class BEncodeRevisionSerializer1(object):

    """Simple revision serializer based around bencode.

    """

    # Maps {key:(Revision attribute, bencode_type, validator)}

    # This tells us what kind we expect bdecode to create, what variable on

    # Revision we should be using, and a function to call to validate/transform

    # the type.

    # TODO: add a 'validate_utf8' for things like revision_id and file_id

    #       and a validator for parent-ids

    _schema = {'format': (None, int, _is_format_10),

               'committer': ('committer', str, cache_utf8.decode),

               'timezone': ('timezone', int, None),

               'timestamp': ('timestamp', str, float),

               'revision-id': ('revision_id', str, None),

               'parent-ids': ('parent_ids', list, None),

               'inventory-sha1': ('inventory_sha1', str, None),

               'message': ('message', str, cache_utf8.decode),

               'properties': ('properties', dict, _validate_properties),

    }

    def write_revision_to_string(self, rev):

        encode_utf8 = cache_utf8._utf8_encode

        # Use a list of tuples rather than a dict

        # This lets us control the ordering, so that we are able to create

        # smaller deltas

        ret = [

            ("format", 10),

            ("committer", encode_utf8(rev.committer)[0]),

        ]

        if rev.timezone is not None:

            ret.append(("timezone", rev.timezone))

        # For bzr revisions, the most common property is just 'branch-nick'

        # which changes infrequently.

        revprops = {}

        for key, value in rev.properties.iteritems():

            revprops[key] = encode_utf8(value)[0]

        ret.append(('properties', revprops))

        ret.extend([

            ("timestamp", "%.3f" % rev.timestamp),

            ("revision-id", rev.revision_id),

            ("parent-ids", rev.parent_ids),

            ("inventory-sha1", rev.inventory_sha1),

            ("message", encode_utf8(rev.message)[0]),

        ])

        return bencode.bencode(ret)

    def write_revision(self, rev, f):

        f.write(self.write_revision_to_string(rev))

    def read_revision_from_string(self, text):

        # TODO: consider writing a Revision decoder, rather than using the

        #       generic bencode decoder

        #       However, to decode all 25k revisions of bzr takes approx 1.3s

        #       If we remove all extra validation that goes down to about 1.2s.

        #       Of that time, probably 0.6s is spend in bencode.bdecode().

        #       Regardless 'time bzr log' of everything is 7+s, so 1.3s to

        #       extract revision texts isn't a majority of time.

        ret = bencode.bdecode(text)

        if not isinstance(ret, list):

            raise ValueError("invalid revision text")

        schema = self._schema

        # timezone is allowed to be missing, but should be set

        bits = {'timezone': None}

        for key, value in ret:

            # Will raise KeyError if not a valid part of the schema, or an

            # entry is given 2 times.

            var_name, expected_type, validator = schema[key]

            if value.__class__ is not expected_type:

                raise ValueError('key %s did not conform to the expected type'

                                 ' %s, but was %s'

                                 % (key, expected_type, type(value)))

            if validator is not None:

                value = validator(value)

            bits[var_name] = value

        if len(bits) != len(schema):

            missing = [key for key, (var_name, _, _) in schema.iteritems()

                       if var_name not in bits]

            raise ValueError('Revision text was missing expected keys %s.'

                             ' text %r' % (missing, text))

        del bits[None]  # Get rid of 'format' since it doesn't get mapped

        rev = _mod_revision.Revision(**bits)

        return rev

    def read_revision(self, f):

        return self.read_revision_from_string(f.read())

class CHKSerializerSubtree(BEncodeRevisionSerializer1, xml6.Serializer_v6):

    """A CHKInventory based serializer that supports tree references"""

    supported_kinds = set(['file', 'directory', 'symlink', 'tree-reference'])

    format_num = '9'

    revision_format_num = None

    support_altered_by_hack = False

    def _unpack_entry(self, elt):

        kind = elt.tag

        if not kind in self.supported_kinds:

            raise AssertionError('unsupported entry kind %s' % kind)

        if kind == 'tree-reference':

            file_id = elt.attrib['file_id']

            name = elt.attrib['name']

            parent_id = elt.attrib['parent_id']

            revision = elt.get('revision')

            reference_revision = elt.get('reference_revision')

            return inventory.TreeReference(file_id, name, parent_id, revision,

                                           reference_revision)

        else:

            return xml6.Serializer_v6._unpack_entry(self, elt)

    def __init__(self, node_size, search_key_name):

        self.maximum_size = node_size

        self.search_key_name = search_key_name

class CHKSerializer(xml5.Serializer_v5):

    """A CHKInventory based serializer with 'plain' behaviour."""

    format_num = '9'

    revision_format_num = None

    support_altered_by_hack = False

    def __init__(self, node_size, search_key_name):

        self.maximum_size = node_size

        self.search_key_name = search_key_name

chk_serializer_255_bigpage = CHKSerializer(65536, 'hash-255-way')

class CHKBEncodeSerializer(BEncodeRevisionSerializer1, CHKSerializer):

    """A CHKInventory and BEncode based serializer with 'plain' behaviour."""

    format_num = '10'

chk_bencode_serializer = CHKBEncodeSerializer(65536, 'hash-255-way')