odps/tunnel/checksum.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 1999-2024 Alibaba Group Holding Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


import struct

from .. import utils
from ..crc import Crc32, Crc32c


class Checksum(object):
    TRUE = bytearray([1])
    FALSE = bytearray([0])

    def __init__(self, method="crc32c"):
        self.crc = Crc32c() if method.lower() == "crc32c" else Crc32()

    def _mode(self):
        # use for UT to check if use c extension
        try:
            from ..src.crc32c_c import Crc32c

            return "c" if isinstance(self.crc, Crc32c) else "py"
        except ImportError:
            return "py"

    def update_bool(self, val):
        assert isinstance(val, bool)

        val = self.TRUE if val else self.FALSE
        self._update(val)

    def update_int(self, val):
        val = struct.pack("<i", val)
        self._update(val)

    def update_long(self, val):
        val = struct.pack("<q", val)
        self._update(val)

    def update_float(self, val):
        val = struct.pack("<f", val)
        self._update(val)

    def update_double(self, val):
        val = struct.pack("<d", val)
        self._update(val)

    def _update(self, b):
        # update crc without type checking
        self.crc.update(bytearray(b))

    def update(self, b):
        b = utils.to_binary(b)
        self._update(b)

    def getvalue(self):
        return self.crc.getvalue()

    def reset(self):
        return self.crc.reset()