#!/usr/bin/env python3
#
# Tests for dirty bitmaps postcopy migration.
#
# Copyright (c) 2016-2017 Virtuozzo International GmbH. All rights reserved.
#
# 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 os
import iotests
from iotests import qemu_img

debug = False

disk_a = os.path.join(iotests.test_dir, 'disk_a')
disk_b = os.path.join(iotests.test_dir, 'disk_b')
size = '256G'
fifo = os.path.join(iotests.test_dir, 'mig_fifo')


def event_seconds(event):
    return event['timestamp']['seconds'] + \
        event['timestamp']['microseconds'] / 1000000.0


def event_dist(e1, e2):
    return event_seconds(e2) - event_seconds(e1)


class TestDirtyBitmapPostcopyMigration(iotests.QMPTestCase):
    def tearDown(self):
        if debug:
            self.vm_a_events += self.vm_a.get_qmp_events()
            self.vm_b_events += self.vm_b.get_qmp_events()
            for e in self.vm_a_events:
                e['vm'] = 'SRC'
            for e in self.vm_b_events:
                e['vm'] = 'DST'
            events = (self.vm_a_events + self.vm_b_events)
            events = [(e['timestamp']['seconds'],
                       e['timestamp']['microseconds'],
                       e['vm'],
                       e['event'],
                       e.get('data', '')) for e in events]
            for e in sorted(events):
                print('{}.{:06} {} {} {}'.format(*e))

        self.vm_a.shutdown()
        self.vm_b.shutdown()
        os.remove(disk_a)
        os.remove(disk_b)
        os.remove(fifo)

    def setUp(self):
        os.mkfifo(fifo)
        qemu_img('create', '-f', iotests.imgfmt, disk_a, size)
        qemu_img('create', '-f', iotests.imgfmt, disk_b, size)
        self.vm_a = iotests.VM(path_suffix='a').add_drive(disk_a)
        self.vm_b = iotests.VM(path_suffix='b').add_drive(disk_b)
        self.vm_b.add_incoming("exec: cat '" + fifo + "'")
        self.vm_a.launch()
        self.vm_b.launch()

        # collect received events for debug
        self.vm_a_events = []
        self.vm_b_events = []

    def test_postcopy(self):
        write_size = 0x40000000
        granularity = 512
        chunk = 4096

        result = self.vm_a.qmp('block-dirty-bitmap-add', node='drive0',
                               name='bitmap', granularity=granularity)
        self.assert_qmp(result, 'return', {})

        s = 0
        while s < write_size:
            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
            s += 0x10000
        s = 0x8000
        while s < write_size:
            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
            s += 0x10000

        result = self.vm_a.qmp('x-debug-block-dirty-bitmap-sha256',
                               node='drive0', name='bitmap')
        sha256 = result['return']['sha256']

        result = self.vm_a.qmp('block-dirty-bitmap-clear', node='drive0',
                               name='bitmap')
        self.assert_qmp(result, 'return', {})
        s = 0
        while s < write_size:
            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
            s += 0x10000

        caps = [{'capability': 'dirty-bitmaps', 'state': True},
                {'capability': 'events', 'state': True}]

        result = self.vm_a.qmp('migrate-set-capabilities', capabilities=caps)
        self.assert_qmp(result, 'return', {})

        result = self.vm_b.qmp('migrate-set-capabilities', capabilities=caps)
        self.assert_qmp(result, 'return', {})

        result = self.vm_a.qmp('migrate', uri='exec:cat>' + fifo)
        self.assert_qmp(result, 'return', {})

        result = self.vm_a.qmp('migrate-start-postcopy')
        self.assert_qmp(result, 'return', {})

        event_resume = self.vm_b.event_wait('RESUME')
        self.vm_b_events.append(event_resume)

        s = 0x8000
        while s < write_size:
            self.vm_b.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
            s += 0x10000

        match = {'data': {'status': 'completed'}}
        event_complete = self.vm_b.event_wait('MIGRATION', match=match)
        self.vm_b_events.append(event_complete)

        # take queued event, should already been happened
        event_stop = self.vm_a.event_wait('STOP')
        self.vm_a_events.append(event_stop)

        downtime = event_dist(event_stop, event_resume)
        postcopy_time = event_dist(event_resume, event_complete)

        # TODO: assert downtime * 10 < postcopy_time
        if debug:
            print('downtime:', downtime)
            print('postcopy_time:', postcopy_time)

        # Assert that bitmap migration is finished (check that successor bitmap
        # is removed)
        result = self.vm_b.qmp('query-block')
        assert len(result['return'][0]['dirty-bitmaps']) == 1

        # Check content of migrated (and updated by new writes) bitmap
        result = self.vm_b.qmp('x-debug-block-dirty-bitmap-sha256',
                               node='drive0', name='bitmap')
        self.assert_qmp(result, 'return/sha256', sha256)


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