#!/usr/bin/env python3
#
# Tests for persistent dirty bitmaps.
#
# Copyright: Vladimir Sementsov-Ogievskiy 2015-2017
#
# 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 re
import iotests
from iotests import qemu_img

disk = os.path.join(iotests.test_dir, 'disk')
disk_size = 0x40000000 # 1G

# regions for qemu_io: (start, count) in bytes
regions1 = ((0x0fff00, 0x10000),
            (0x200000, 0x100000))

regions2 = ((0x10000000, 0x20000),
            (0x3fff0000, 0x10000))

class TestPersistentDirtyBitmap(iotests.QMPTestCase):

    def setUp(self):
        qemu_img('create', '-f', iotests.imgfmt, disk, str(disk_size))

    def tearDown(self):
        os.remove(disk)

    def mkVm(self):
        return iotests.VM().add_drive(disk, opts='node-name=node0')

    def mkVmRo(self):
        return iotests.VM().add_drive(disk, opts='readonly=on,node-name=node0')

    def getSha256(self):
        result = self.vm.qmp('x-debug-block-dirty-bitmap-sha256',
                             node='drive0', name='bitmap0')
        return result['return']['sha256']

    def checkBitmap(self, sha256):
        result = self.vm.qmp('x-debug-block-dirty-bitmap-sha256',
                             node='drive0', name='bitmap0')
        self.assert_qmp(result, 'return/sha256', sha256);

    def writeRegions(self, regions):
        for r in regions:
            self.vm.hmp_qemu_io('drive0',
                                'write %d %d' % r)

    def qmpAddBitmap(self):
        self.vm.qmp('block-dirty-bitmap-add', node='drive0',
                    name='bitmap0', persistent=True)

    def test_persistent(self):
        self.vm = self.mkVm()
        self.vm.launch()
        self.qmpAddBitmap()

        self.writeRegions(regions1)
        sha256 = self.getSha256()

        self.vm.shutdown()

        self.vm = self.mkVmRo()
        self.vm.launch()
        self.vm.shutdown()

        #catch 'Persistent bitmaps are lost' possible error
        log = self.vm.get_log()
        log = re.sub(r'^\[I \d+\.\d+\] OPENED\n', '', log)
        log = re.sub(r'\[I \+\d+\.\d+\] CLOSED\n?$', '', log)
        if log:
            print(log)

        self.vm = self.mkVm()
        self.vm.launch()

        self.checkBitmap(sha256)
        self.writeRegions(regions2)
        sha256 = self.getSha256()

        self.vm.shutdown()
        self.vm.launch()

        self.checkBitmap(sha256)

        self.vm.shutdown()

    def test_reopen_rw(self):
        self.vm = self.mkVm()
        self.vm.launch()
        self.qmpAddBitmap()

        # Calculate hashes

        self.writeRegions(regions1)
        sha256_1 = self.getSha256()

        self.writeRegions(regions2)
        sha256_2 = self.getSha256()
        assert sha256_1 != sha256_2 # Otherwise, it's not very interesting.

        result = self.vm.qmp('block-dirty-bitmap-clear', node='drive0',
                             name='bitmap0')
        self.assert_qmp(result, 'return', {})

        # Start with regions1

        self.writeRegions(regions1)
        assert sha256_1 == self.getSha256()

        self.vm.shutdown()

        self.vm = self.mkVmRo()
        self.vm.launch()

        assert sha256_1 == self.getSha256()

        # Check that we are in RO mode and can't modify bitmap.
        self.writeRegions(regions2)
        assert sha256_1 == self.getSha256()

        # Reopen to RW
        result = self.vm.qmp('x-blockdev-reopen', **{
            'node-name': 'node0',
            'driver': iotests.imgfmt,
            'file': {
                'driver': 'file',
                'filename': disk
            },
            'read-only': False
        })
        self.assert_qmp(result, 'return', {})

        # Check that bitmap is reopened to RW and we can write to it.
        self.writeRegions(regions2)
        assert sha256_2 == self.getSha256()

        self.vm.shutdown()


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