view mercurial/dirstateutils/docket.py @ 49037:642e31cb55f0

py3: use class X: instead of class X(object):

The inheritance from object is implied in Python 3. So this should
be equivalent.

This change was generated via an automated search and replace. So there
may have been some accidental changes.

Differential Revision: https://phab.mercurial-scm.org/D12352

# dirstatedocket.py - docket file for dirstate-v2
#
# Copyright Mercurial Contributors
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.


import struct

from ..revlogutils import docket as docket_mod
from . import v2

V2_FORMAT_MARKER = b"dirstate-v2\n"

# * 12 bytes: format marker
# * 32 bytes: node ID of the working directory's first parent
# * 32 bytes: node ID of the working directory's second parent
# * {TREE_METADATA_SIZE} bytes: tree metadata, parsed separately
# * 4 bytes: big-endian used size of the data file
# * 1 byte: length of the data file's UUID
# * variable: data file's UUID
#
# Node IDs are null-padded if shorter than 32 bytes.
# A data file shorter than the specified used size is corrupted (truncated)
HEADER = struct.Struct(
    ">{}s32s32s{}sLB".format(len(V2_FORMAT_MARKER), v2.TREE_METADATA_SIZE)
)


class DirstateDocket:
    data_filename_pattern = b'dirstate.%s'

    def __init__(self, parents, data_size, tree_metadata, uuid):
        self.parents = parents
        self.data_size = data_size
        self.tree_metadata = tree_metadata
        self.uuid = uuid

    @classmethod
    def with_new_uuid(cls, parents, data_size, tree_metadata):
        return cls(parents, data_size, tree_metadata, docket_mod.make_uid())

    @classmethod
    def parse(cls, data, nodeconstants):
        if not data:
            parents = (nodeconstants.nullid, nodeconstants.nullid)
            return cls(parents, 0, b'', None)
        marker, p1, p2, meta, data_size, uuid_size = HEADER.unpack_from(data)
        if marker != V2_FORMAT_MARKER:
            raise ValueError("expected dirstate-v2 marker")
        uuid = data[HEADER.size : HEADER.size + uuid_size]
        p1 = p1[: nodeconstants.nodelen]
        p2 = p2[: nodeconstants.nodelen]
        return cls((p1, p2), data_size, meta, uuid)

    def serialize(self):
        p1, p2 = self.parents
        header = HEADER.pack(
            V2_FORMAT_MARKER,
            p1,
            p2,
            self.tree_metadata,
            self.data_size,
            len(self.uuid),
        )
        return header + self.uuid

    def data_filename(self):
        return self.data_filename_pattern % self.uuid