#!/usr/bin/env python3
# group: rw migration
#
# Tests for dirty bitmaps 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 itertools
import operator
import os
import re

import iotests
from iotests import qemu_img, qemu_img_create, Timeout


disk_a = os.path.join(iotests.test_dir, 'disk_a')
disk_b = os.path.join(iotests.test_dir, 'disk_b')
base_a = os.path.join(iotests.test_dir, 'base_a')
size = '1M'
mig_file = os.path.join(iotests.test_dir, 'mig_file')
mig_cmd = 'exec: cat > ' + mig_file
incoming_cmd = 'exec: cat ' + mig_file


def get_bitmap_hash(vm):
    result = vm.qmp('x-debug-block-dirty-bitmap-sha256',
                    node='drive0', name='bitmap0')
    return result['return']['sha256']


class TestDirtyBitmapMigration(iotests.QMPTestCase):
    def tearDown(self):
        self.vm_a.shutdown()
        self.vm_b.shutdown()
        os.remove(disk_a)
        os.remove(disk_b)
        os.remove(mig_file)

    def setUp(self):
        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_a.launch()

        self.vm_b = iotests.VM(path_suffix='b')

    def add_bitmap(self, vm, granularity, persistent):
        params = {'node': 'drive0',
                  'name': 'bitmap0',
                  'granularity': granularity}
        if persistent:
            params['persistent'] = True

        result = vm.qmp('block-dirty-bitmap-add', **params)
        self.assert_qmp(result, 'return', {})

    def check_bitmap(self, vm, sha256):
        result = vm.qmp('x-debug-block-dirty-bitmap-sha256',
                        node='drive0', name='bitmap0')
        if sha256:
            self.assert_qmp(result, 'return/sha256', sha256)
        else:
            self.assert_qmp(result, 'error/desc',
                            "Dirty bitmap 'bitmap0' not found")

    def do_test_migration_resume_source(self, persistent, migrate_bitmaps):
        granularity = 512

        # regions = ((start, count), ...)
        regions = ((0, 0x10000),
                   (0xf0000, 0x10000),
                   (0xa0201, 0x1000))

        mig_caps = [{'capability': 'events', 'state': True}]
        if migrate_bitmaps:
            mig_caps.append({'capability': 'dirty-bitmaps', 'state': True})

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

        self.add_bitmap(self.vm_a, granularity, persistent)
        for r in regions:
            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % r)
        sha256 = get_bitmap_hash(self.vm_a)

        result = self.vm_a.qmp('migrate', uri=mig_cmd)
        while True:
            event = self.vm_a.event_wait('MIGRATION')
            if event['data']['status'] == 'completed':
                break
        while True:
            result = self.vm_a.qmp('query-status')
            if result['return']['status'] == 'postmigrate':
                break

        # test that bitmap is still here
        removed = (not migrate_bitmaps) and persistent
        self.check_bitmap(self.vm_a, False if removed else sha256)

        result = self.vm_a.qmp('cont')
        self.assert_qmp(result, 'return', {})

        # test that bitmap is still here after invalidation
        self.check_bitmap(self.vm_a, sha256)

        # shutdown and check that invalidation didn't fail
        self.vm_a.shutdown()

        # catch 'Could not reopen qcow2 layer: Bitmap already exists'
        # possible error
        log = self.vm_a.get_log()
        log = re.sub(r'^\[I \d+\.\d+\] OPENED\n', '', log)
        log = re.sub(r'^(wrote .* bytes at offset .*\n.*KiB.*ops.*sec.*\n){3}',
                     '', log)
        log = re.sub(r'\[I \+\d+\.\d+\] CLOSED\n?$', '', log)
        self.assertEqual(log, '')

        # test that bitmap is still persistent
        self.vm_a.launch()
        self.check_bitmap(self.vm_a, sha256 if persistent else False)

    def do_test_migration(self, persistent, migrate_bitmaps, online,
                          shared_storage, pre_shutdown):
        granularity = 512

        # regions = ((start, count), ...)
        regions = ((0, 0x10000),
                   (0xf0000, 0x10000),
                   (0xa0201, 0x1000))

        should_migrate = \
            (migrate_bitmaps and (persistent or not pre_shutdown)) or \
            (persistent and shared_storage)
        mig_caps = [{'capability': 'events', 'state': True}]
        if migrate_bitmaps:
            mig_caps.append({'capability': 'dirty-bitmaps', 'state': True})

        self.vm_b.add_incoming(incoming_cmd if online else "defer")
        self.vm_b.add_drive(disk_a if shared_storage else disk_b)

        if online:
            os.mkfifo(mig_file)
            self.vm_b.launch()
            result = self.vm_b.qmp('migrate-set-capabilities',
                                   capabilities=mig_caps)
            self.assert_qmp(result, 'return', {})

        self.add_bitmap(self.vm_a, granularity, persistent)
        for r in regions:
            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % r)
        sha256 = get_bitmap_hash(self.vm_a)

        if pre_shutdown:
            self.vm_a.shutdown()
            self.vm_a.launch()

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

        result = self.vm_a.qmp('migrate', uri=mig_cmd)
        while True:
            event = self.vm_a.event_wait('MIGRATION')
            if event['data']['status'] == 'completed':
                break

        if not online:
            self.vm_a.shutdown()
            self.vm_b.launch()
            result = self.vm_b.qmp('migrate-set-capabilities',
                                   capabilities=mig_caps)
            self.assert_qmp(result, 'return', {})
            result = self.vm_b.qmp('migrate-incoming', uri=incoming_cmd)
            self.assert_qmp(result, 'return', {})

        while True:
            event = self.vm_b.event_wait('MIGRATION')
            if event['data']['status'] == 'completed':
                break

        self.check_bitmap(self.vm_b, sha256 if should_migrate else False)

        if should_migrate:
            self.vm_b.shutdown()

            # catch 'Could not reopen qcow2 layer: Bitmap already exists'
            # possible error
            log = self.vm_b.get_log()
            log = re.sub(r'^\[I \d+\.\d+\] OPENED\n', '', log)
            log = re.sub(r'\[I \+\d+\.\d+\] CLOSED\n?$', '', log)
            self.assertEqual(log, '')

            # recreate vm_b, as we don't want -incoming option (this will lead
            # to "cat" process left alive after test finish)
            self.vm_b = iotests.VM(path_suffix='b')
            self.vm_b.add_drive(disk_a if shared_storage else disk_b)
            self.vm_b.launch()
            self.check_bitmap(self.vm_b, sha256 if persistent else False)


def inject_test_case(klass, suffix, method, *args, **kwargs):
    mc = operator.methodcaller(method, *args, **kwargs)
    # We want to add a function attribute to `klass`, so that it is
    # correctly converted to a method on instantiation.  The
    # methodcaller object `mc` is a callable, not a function, so we
    # need the lambda to turn it into a function.
    # pylint: disable=unnecessary-lambda
    setattr(klass, 'test_' + method + suffix, lambda self: mc(self))


class TestDirtyBitmapBackingMigration(iotests.QMPTestCase):
    def setUp(self):
        qemu_img_create('-f', iotests.imgfmt, base_a, size)
        qemu_img_create('-f', iotests.imgfmt, '-F', iotests.imgfmt,
                        '-b', base_a, disk_a, size)

        for f in (disk_a, base_a):
            qemu_img('bitmap', '--add', f, 'bmap0')

        blockdev = {
            'node-name': 'node0',
            'driver': iotests.imgfmt,
            'file': {
                'driver': 'file',
                'filename': disk_a
            },
            'backing': {
                'node-name': 'node0-base',
                'driver': iotests.imgfmt,
                'file': {
                    'driver': 'file',
                    'filename': base_a
                }
            }
        }

        self.vm = iotests.VM()
        self.vm.launch()

        result = self.vm.qmp('blockdev-add', **blockdev)
        self.assert_qmp(result, 'return', {})

        # Check that the bitmaps are there
        nodes = self.vm.qmp('query-named-block-nodes', flat=True)['return']
        for node in nodes:
            if 'node0' in node['node-name']:
                self.assert_qmp(node, 'dirty-bitmaps[0]/name', 'bmap0')

        caps = [{'capability': 'events', 'state': True}]
        result = self.vm.qmp('migrate-set-capabilities', capabilities=caps)
        self.assert_qmp(result, 'return', {})

    def tearDown(self):
        self.vm.shutdown()
        for f in (disk_a, base_a):
            os.remove(f)

    def test_cont_on_source(self):
        """
        Continue the source after migration.
        """
        result = self.vm.qmp('migrate', uri='exec: cat > /dev/null')
        self.assert_qmp(result, 'return', {})

        with Timeout(10, 'Migration timeout'):
            self.vm.wait_migration('postmigrate')

        result = self.vm.qmp('cont')
        self.assert_qmp(result, 'return', {})


def main() -> None:
    for cmb in list(itertools.product((True, False), repeat=5)):
        name = ('_' if cmb[0] else '_not_') + 'persistent_'
        name += ('_' if cmb[1] else '_not_') + 'migbitmap_'
        name += '_online' if cmb[2] else '_offline'
        name += '_shared' if cmb[3] else '_nonshared'
        if cmb[4]:
            name += '__pre_shutdown'

        inject_test_case(TestDirtyBitmapMigration, name, 'do_test_migration',
                         *list(cmb))

    for cmb in list(itertools.product((True, False), repeat=2)):
        name = ('_' if cmb[0] else '_not_') + 'persistent_'
        name += ('_' if cmb[1] else '_not_') + 'migbitmap'

        inject_test_case(TestDirtyBitmapMigration, name,
                         'do_test_migration_resume_source', *list(cmb))

    iotests.main(
        supported_fmts=['qcow2'],
        supported_protocols=['file']
    )


if __name__ == '__main__':
    main()