Пример #1
0
    def _encode_msg(self,
                    start_pos,
                    offset,
                    timestamp,
                    key,
                    value,
                    attributes=0):
        """ Encode msg data into the `msg_buffer`, which should be allocated
            to at least the size of this message.
        """
        magic = self._magic
        buf = self._buffer
        pos = start_pos

        # Write key and value
        pos += self.KEY_OFFSET_V0 if magic == 0 else self.KEY_OFFSET_V1

        if key is None:
            struct.pack_into(">i", buf, pos, -1)
            pos += self.KEY_LENGTH
        else:
            key_size = len(key)
            struct.pack_into(">i", buf, pos, key_size)
            pos += self.KEY_LENGTH
            buf[pos:pos + key_size] = key
            pos += key_size

        if value is None:
            struct.pack_into(">i", buf, pos, -1)
            pos += self.VALUE_LENGTH
        else:
            value_size = len(value)
            struct.pack_into(">i", buf, pos, value_size)
            pos += self.VALUE_LENGTH
            buf[pos:pos + value_size] = value
            pos += value_size
        length = (pos - start_pos) - self.LOG_OVERHEAD

        # Write msg header. Note, that Crc will be updated later
        if magic == 0:
            self.HEADER_STRUCT_V0.pack_into(buf, start_pos, offset, length, 0,
                                            magic, attributes)
        else:
            self.HEADER_STRUCT_V1.pack_into(buf, start_pos, offset, length, 0,
                                            magic, attributes, timestamp)

        # Calculate CRC for msg
        crc_data = memoryview(buf)[start_pos + self.MAGIC_OFFSET:]
        crc = calc_crc32(crc_data)
        struct.pack_into(">I", buf, start_pos + self.CRC_OFFSET, crc)
        return crc
Пример #2
0
    def _encode_msg(self, start_pos, offset, timestamp, key, value,
                    attributes=0):
        """ Encode msg data into the `msg_buffer`, which should be allocated
            to at least the size of this message.
        """
        magic = self._magic
        buf = self._buffer
        pos = start_pos

        # Write key and value
        pos += self.KEY_OFFSET_V0 if magic == 0 else self.KEY_OFFSET_V1

        if key is None:
            struct.pack_into(">i", buf, pos, -1)
            pos += self.KEY_LENGTH
        else:
            key_size = len(key)
            struct.pack_into(">i", buf, pos, key_size)
            pos += self.KEY_LENGTH
            buf[pos: pos + key_size] = key
            pos += key_size

        if value is None:
            struct.pack_into(">i", buf, pos, -1)
            pos += self.VALUE_LENGTH
        else:
            value_size = len(value)
            struct.pack_into(">i", buf, pos, value_size)
            pos += self.VALUE_LENGTH
            buf[pos: pos + value_size] = value
            pos += value_size
        length = (pos - start_pos) - self.LOG_OVERHEAD

        # Write msg header. Note, that Crc will be updated later
        if magic == 0:
            self.HEADER_STRUCT_V0.pack_into(
                buf, start_pos,
                offset, length, 0, magic, attributes)
        else:
            self.HEADER_STRUCT_V1.pack_into(
                buf, start_pos,
                offset, length, 0, magic, attributes, timestamp)

        # Calculate CRC for msg
        crc_data = memoryview(buf)[start_pos + self.MAGIC_OFFSET:]
        crc = calc_crc32(crc_data)
        struct.pack_into(">I", buf, start_pos + self.CRC_OFFSET, crc)
        return crc
Пример #3
0
 def validate_crc(self):
     crc = calc_crc32(self._buffer[self.MAGIC_OFFSET:])
     return self._crc == crc
Пример #4
0
 def validate_crc(self):
     crc = calc_crc32(self._buffer[self.MAGIC_OFFSET:])
     return self._crc == crc