Python BufferedReader.seek方法代码示例

# 需要导入模块: from io import BufferedReader [as 别名]
# 或者: from io.BufferedReader import seek [as 别名]
    def load(cls, filename, metadata_only=False):
        """
        Load ring data from a file.

        :param filename: Path to a file serialized by the save() method.
        :param bool metadata_only: If True, only load `devs` and `part_shift`.
        :returns: A RingData instance containing the loaded data.
        """
        gz_file = BufferedReader(GzipFile(filename, 'rb'))

        # See if the file is in the new format
        magic = gz_file.read(4)
        if magic == b'R1NG':
            format_version, = struct.unpack('!H', gz_file.read(2))
            if format_version == 1:
                ring_data = cls.deserialize_v1(
                    gz_file, metadata_only=metadata_only)
            else:
                raise Exception('Unknown ring format version %d' %
                                format_version)
        else:
            # Assume old-style pickled ring
            gz_file.seek(0)
            ring_data = pickle.load(gz_file)

        if not hasattr(ring_data, 'devs'):
            ring_data = RingData(ring_data['replica2part2dev_id'],
                                 ring_data['devs'], ring_data['part_shift'],
                                 ring_data.get('next_part_power'))
        return ring_data

# 需要导入模块: from io import BufferedReader [as 别名]
# 或者: from io.BufferedReader import seek [as 别名]

#.........这里部分代码省略.........
            length = first_byte
            padding = (length + 1) % 4

        data = self.read(length)
        if padding > 0:
            padding = 4 - padding
            self.read(padding)

        return data

    def tgread_string(self):
        """Reads a Telegram-encoded string."""
        return str(self.tgread_bytes(), encoding='utf-8', errors='replace')

    def tgread_bool(self):
        """Reads a Telegram boolean value."""
        value = self.read_int(signed=False)
        if value == 0x997275b5:  # boolTrue
            return True
        elif value == 0xbc799737:  # boolFalse
            return False
        else:
            raise RuntimeError('Invalid boolean code {}'.format(hex(value)))

    def tgread_date(self):
        """Reads and converts Unix time (used by Telegram)
           into a Python datetime object.
        """
        value = self.read_int()
        if value == 0:
            return None
        else:
            return datetime.fromtimestamp(value, tz=timezone.utc)

    def tgread_object(self):
        """Reads a Telegram object."""
        constructor_id = self.read_int(signed=False)
        clazz = tlobjects.get(constructor_id, None)
        if clazz is None:
            # The class was None, but there's still a
            # chance of it being a manually parsed value like bool!
            value = constructor_id
            if value == 0x997275b5:  # boolTrue
                return True
            elif value == 0xbc799737:  # boolFalse
                return False
            elif value == 0x1cb5c415:  # Vector
                return [self.tgread_object() for _ in range(self.read_int())]

            clazz = core_objects.get(constructor_id, None)
            if clazz is None:
                # If there was still no luck, give up
                self.seek(-4)  # Go back
                pos = self.tell_position()
                error = TypeNotFoundError(constructor_id, self.read())
                self.set_position(pos)
                raise error

        return clazz.from_reader(self)

    def tgread_vector(self):
        """Reads a vector (a list) of Telegram objects."""
        if 0x1cb5c415 != self.read_int(signed=False):
            raise RuntimeError('Invalid constructor code, vector was expected')

        count = self.read_int()
        return [self.tgread_object() for _ in range(count)]

    # endregion

    def close(self):
        """Closes the reader, freeing the BytesIO stream."""
        self.reader.close()

    # region Position related

    def tell_position(self):
        """Tells the current position on the stream."""
        return self.reader.tell()

    def set_position(self, position):
        """Sets the current position on the stream."""
        self.reader.seek(position)

    def seek(self, offset):
        """
        Seeks the stream position given an offset from the current position.
        The offset may be negative.
        """
        self.reader.seek(offset, os.SEEK_CUR)

    # endregion

    # region with block

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()