#!/usr/bin/env python3
# group: rw
#
# Test nbd reconnect
#
# Copyright (c) 2019 Virtuozzo International GmbH.
#
# 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, see <http://www.gnu.org/licenses/>.
#

import time
import os

import iotests
from iotests import qemu_img_create, file_path, qemu_nbd_popen

disk_a, disk_b, nbd_sock = file_path('disk_a', 'disk_b', 'nbd-sock')
nbd_uri = 'nbd+unix:///?socket=' + nbd_sock
wait_limit = 3.0
wait_step = 0.2


class TestNbdReconnect(iotests.QMPTestCase):
    def init_vm(self, disk_size):
        qemu_img_create('-f', iotests.imgfmt, disk_a, str(disk_size))
        qemu_img_create('-f', iotests.imgfmt, disk_b, str(disk_size))
        self.vm = iotests.VM().add_drive(disk_a)
        self.vm.launch()
        self.vm.hmp_qemu_io('drive0', 'write 0 {}'.format(disk_size))

    def tearDown(self):
        self.vm.shutdown()
        os.remove(disk_a)
        os.remove(disk_b)

    def start_job(self, job):
        """Stat job with nbd target and kill the server"""
        assert job in ('blockdev-backup', 'blockdev-mirror')
        with qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b):
            result = self.vm.qmp('blockdev-add',
                                 **{'node_name': 'backup0',
                                    'driver': 'raw',
                                    'file': {'driver': 'nbd',
                                             'server': {'type': 'unix',
                                                        'path': nbd_sock},
                                             'reconnect-delay': 10}})
            self.assert_qmp(result, 'return', {})
            result = self.vm.qmp(job, device='drive0',
                                 sync='full', target='backup0',
                                 speed=(1 * 1024 * 1024))
            self.assert_qmp(result, 'return', {})

            # Wait for some progress
            t = 0.0
            while t < wait_limit:
                jobs = self.vm.qmp('query-block-jobs')['return']
                if jobs and jobs[0]['offset'] > 0:
                    break
                time.sleep(wait_step)
                t += wait_step

            self.assertTrue(jobs and jobs[0]['offset'] > 0)  # job started

        jobs = self.vm.qmp('query-block-jobs')['return']
        # Check that job is still in progress
        self.assertTrue(jobs)
        self.assertTrue(jobs[0]['offset'] < jobs[0]['len'])

        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
        self.assert_qmp(result, 'return', {})

        # Emulate server down time for 1 second
        time.sleep(1)

    def test_backup(self):
        size = 5 * 1024 * 1024
        self.init_vm(size)
        self.start_job('blockdev-backup')

        with qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b):
            e = self.vm.event_wait('BLOCK_JOB_COMPLETED')
            self.assertEqual(e['data']['offset'], size)
            result = self.vm.qmp('blockdev-del', node_name='backup0')
            self.assert_qmp(result, 'return', {})

    def cancel_job(self):
        result = self.vm.qmp('block-job-cancel', device='drive0', force=True)
        self.assert_qmp(result, 'return', {})

        start_t = time.time()
        self.vm.event_wait('BLOCK_JOB_CANCELLED')
        delta_t = time.time() - start_t
        self.assertTrue(delta_t < 2.0)

    def test_mirror_cancel(self):
        # Mirror speed limit doesn't work well enough, it seems that mirror
        # will run many parallel requests anyway. MAX_IN_FLIGHT is 16 and
        # MAX_IO_BYTES is 1M in mirror.c, so let's use 20M disk.
        self.init_vm(20 * 1024 * 1024)
        self.start_job('blockdev-mirror')
        self.cancel_job()

    def test_backup_cancel(self):
        self.init_vm(5 * 1024 * 1024)
        self.start_job('blockdev-backup')
        self.cancel_job()


if __name__ == '__main__':
    iotests.main(supported_fmts=['qcow2'])