nvme_test_io.py

# Copyright (c) 2015-2016 Western Digital Corporation or its affiliates.
#
# 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.
#
#   Author: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com>
#
""" Inherit TestNVMeIO for nvme read/write operations """

import os
from nose import tools
from nvme_test import TestNVMe


class TestNVMeIO(TestNVMe):

    """
    Variable and Methods required to perform nvme read/write.

        - Attributes:
              - data_size : data size to perform IO.
              - start_block : starting block of to perform IO.
              - block_count : Number of blocks to use in IO.
              - write_file : data file to use in nvme write command.
              - read_file : data file to use in nvme read command.
    """

    def __init__(self):
        """ Pre Section for TestNVMeIO """
        TestNVMe.__init__(self)
        # common code used in various testcases.
        self.data_size = 512
        self.start_block = 0
        self.block_count = 0
        self.write_file = "write_file.txt"
        self.read_file = "read_file.txt"

    def __del__(self):
        """ Post Section for TestNVMeIO """
        TestNVMe.__del__(self)

    @tools.nottest
    def create_data_file(self, pathname, data_size, pattern):
        """ Creates data file with specific pattern
            - Args:
                - pathname : data file path name.
                - data_size : total size of the data.
                - pattern : data pattern to create file.
            - Returns:
            None
        """
        pattern_len = len(pattern)
        data_file = open(pathname, "w")
        for i in range(0, data_size):
            data_file.write(pattern[i % pattern_len])
        data_file.flush()
        os.fsync(data_file.fileno())
        data_file.close()

    @tools.nottest
    def nvme_write(self):
        """ Wrapper for nvme write operation
            - Args:
                - None
            - Returns:
                - return code for nvme write command.
        """
        write_cmd = "nvme write " + self.ns1 + " --start-block=" + \
                    str(self.start_block) + " --block-count=" + \
                    str(self.block_count) + " --data-size=" + \
                    str(self.data_size) + " --data=" + self.write_file
        return self.exec_cmd(write_cmd)

    @tools.nottest
    def nvme_read(self):
        """ Wrapper for nvme read operation
            - Args:
                - None
            - Returns:
                - return code for nvme read command.
        """
        read_cmd = "nvme read " + self.ns1 + " --start-block=" + \
                   str(self.start_block) + " --block-count=" + \
                   str(self.block_count) + " --data-size=" + \
                   str(self.data_size) + " --data=" + self.read_file
        print(read_cmd)
        return self.exec_cmd(read_cmd)