# Copyright (c) 2010-2012 OpenStack, LLC.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os
import unittest
from collections import defaultdict
from shutil import rmtree

from swift.common import exceptions
from swift.common import ring
from swift.common.ring import RingBuilder, RingData

class TestRingBuilder(unittest.TestCase):

    def setUp(self):
        self.testdir = os.path.join(os.path.dirname(__file__),
                                    'ring_builder')
        rmtree(self.testdir, ignore_errors=1)
        os.mkdir(self.testdir)

    def tearDown(self):
        rmtree(self.testdir, ignore_errors=1)

    def test_init(self):
        rb = ring.RingBuilder(8, 3, 1)
        self.assertEquals(rb.part_power, 8)
        self.assertEquals(rb.replicas, 3)
        self.assertEquals(rb.min_part_hours, 1)
        self.assertEquals(rb.parts, 2**8)
        self.assertEquals(rb.devs, [])
        self.assertEquals(rb.devs_changed, False)
        self.assertEquals(rb.version, 0)

    def test_get_ring(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10004, 'device': 'sda1'})
        rb.remove_dev(1)
        rb.rebalance()
        r = rb.get_ring()
        self.assert_(isinstance(r, ring.RingData))
        r2 = rb.get_ring()
        self.assert_(r is r2)
        rb.rebalance()
        r3 = rb.get_ring()
        self.assert_(r3 is not r2)
        r4 = rb.get_ring()
        self.assert_(r3 is r4)

    def test_add_dev(self):
        rb = ring.RingBuilder(8, 3, 1)
        dev = \
            {'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1', 'port': 10000}
        rb.add_dev(dev)
        self.assertRaises(exceptions.DuplicateDeviceError, rb.add_dev, dev)

    def test_set_dev_weight(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 0.5, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 0, 'weight': 0.5, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10003, 'device': 'sda1'})
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts, {0: 128, 1: 128, 2: 256, 3: 256})
        rb.set_dev_weight(0, 0.75)
        rb.set_dev_weight(1, 0.25)
        rb.pretend_min_part_hours_passed()
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts, {0: 192, 1: 64, 2: 256, 3: 256})

    def test_remove_dev(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'zone': 3, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10003, 'device': 'sda1'})
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts, {0: 192, 1: 192, 2: 192, 3: 192})
        rb.remove_dev(1)
        rb.pretend_min_part_hours_passed()
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts, {0: 256, 2: 256, 3: 256})

    def test_remove_a_lot(self):
        rb = ring.RingBuilder(3, 3, 1)
        rb.add_dev({'id': 0, 'device': 'd0', 'ip': '10.0.0.1',
                    'port': 6002, 'weight': 1000.0, 'zone': 1})
        rb.add_dev({'id': 1, 'device': 'd1', 'ip': '10.0.0.2',
                    'port': 6002, 'weight': 1000.0, 'zone': 2})
        rb.add_dev({'id': 2, 'device': 'd2', 'ip': '10.0.0.3',
                    'port': 6002, 'weight': 1000.0, 'zone': 3})
        rb.add_dev({'id': 3, 'device': 'd3', 'ip': '10.0.0.1',
                    'port': 6002, 'weight': 1000.0, 'zone': 1})
        rb.add_dev({'id': 4, 'device': 'd4', 'ip': '10.0.0.2',
                    'port': 6002, 'weight': 1000.0, 'zone': 2})
        rb.add_dev({'id': 5, 'device': 'd5', 'ip': '10.0.0.3',
                    'port': 6002, 'weight': 1000.0, 'zone': 3})
        rb.rebalance()
        rb.validate()

        # this has to put more than 1/3 of the partitions in the
        # cluster on removed devices in order to ensure that at least
        # one partition has multiple replicas that need to move.
        #
        # (for an N-replica ring, it's more than 1/N of the
        # partitions, of course)
        rb.remove_dev(3)
        rb.remove_dev(4)
        rb.remove_dev(5)

        rb.rebalance()
        rb.validate()

    def test_shuffled_gather(self):
        if self._shuffled_gather_helper() and \
            self._shuffled_gather_helper():
                raise AssertionError('It is highly likely the ring is no '
                    'longer shuffling the set of partitions to reassign on a '
                    'rebalance.')

    def _shuffled_gather_helper(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sda1'})
        rb.rebalance()
        rb.add_dev({'id': 3, 'zone': 3, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10003, 'device': 'sda1'})
        rb.pretend_min_part_hours_passed()
        parts = rb._gather_reassign_parts()
        max_run = 0
        run = 0
        last_part = 0
        for part, _ in parts:
            if part > last_part:
                run += 1
            else:
                if run > max_run:
                    max_run = run
                run = 0
            last_part = part
        if run > max_run:
            max_run = run
        return max_run > len(parts) / 2

    def test_multitier_partial(self):
        # Multitier test, zones full, nodes not full
        rb = ring.RingBuilder(8, 6, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdb'})
        rb.add_dev({'id': 2, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdc'})

        rb.add_dev({'id': 3, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sdd'})
        rb.add_dev({'id': 4, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sde'})
        rb.add_dev({'id': 5, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sdf'})

        rb.add_dev({'id': 6, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sdg'})
        rb.add_dev({'id': 7, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sdh'})
        rb.add_dev({'id': 8, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sdi'})

        rb.rebalance()
        rb.validate()

        for part in xrange(rb.parts):
            counts = defaultdict(lambda: defaultdict(lambda: 0))
            for replica in xrange(rb.replicas):
                dev = rb.devs[rb._replica2part2dev[replica][part]]
                counts['zone'][dev['zone']] += 1
                counts['dev_id'][dev['id']] += 1
            if counts['zone'] != {0: 2, 1: 2, 2: 2}:
                raise AssertionError(
                    "Partition %d not evenly distributed (got %r)" %
                    (part, counts['zone']))
            for dev_id, replica_count in counts['dev_id'].iteritems():
                if replica_count > 1:
                    raise AssertionError(
                        "Partition %d is on device %d more than once (%r)" %
                        (part, dev_id, counts['dev_id']))

    def test_multitier_full(self):
        # Multitier test, #replicas == #devs
        rb = ring.RingBuilder(8, 6, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdb'})

        rb.add_dev({'id': 2, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdc'})
        rb.add_dev({'id': 3, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sdd'})

        rb.add_dev({'id': 4, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sde'})
        rb.add_dev({'id': 5, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sdf'})

        rb.rebalance()
        rb.validate()

        for part in xrange(rb.parts):
            counts = defaultdict(lambda: defaultdict(lambda: 0))
            for replica in xrange(rb.replicas):
                dev = rb.devs[rb._replica2part2dev[replica][part]]
                counts['zone'][dev['zone']] += 1
                counts['dev_id'][dev['id']] += 1
            if counts['zone'] != {0: 2, 1: 2, 2: 2}:
                raise AssertionError(
                    "Partition %d not evenly distributed (got %r)" %
                    (part, counts['zone']))
            for dev_id, replica_count in counts['dev_id'].iteritems():
                if replica_count != 1:
                    raise AssertionError(
                        "Partition %d is on device %d %d times, not 1 (%r)" %
                        (part, dev_id, replica_count, counts['dev_id']))

    def test_multitier_overfull(self):
        # Multitier test, #replicas > #devs + 2 (to prove even distribution)
        rb = ring.RingBuilder(8, 8, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdb'})

        rb.add_dev({'id': 2, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdc'})
        rb.add_dev({'id': 3, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sdd'})

        rb.add_dev({'id': 4, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sde'})
        rb.add_dev({'id': 5, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sdf'})

        rb.rebalance()
        rb.validate()

        for part in xrange(rb.parts):
            counts = defaultdict(lambda: defaultdict(lambda: 0))
            for replica in xrange(rb.replicas):
                dev = rb.devs[rb._replica2part2dev[replica][part]]
                counts['zone'][dev['zone']] += 1
                counts['dev_id'][dev['id']] += 1

            self.assertEquals(8, sum(counts['zone'].values()))
            for zone, replica_count in counts['zone'].iteritems():
                if replica_count not in (2, 3):
                    raise AssertionError(
                        "Partition %d not evenly distributed (got %r)" %
                        (part, counts['zone']))
            for dev_id, replica_count in counts['dev_id'].iteritems():
                if replica_count not in (1, 2):
                    raise AssertionError(
                        "Partition %d is on device %d %d times, "
                        "not 1 or 2 (%r)" %
                        (part, dev_id, replica_count, counts['dev_id']))

    def test_multitier_expansion_more_devices(self):
        rb = ring.RingBuilder(8, 6, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdb'})
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdc'})

        rb.rebalance()
        rb.validate()

        rb.add_dev({'id': 3, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdd'})
        rb.add_dev({'id': 4, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sde'})
        rb.add_dev({'id': 5, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdf'})

        for _ in xrange(5):
            rb.pretend_min_part_hours_passed()
            rb.rebalance()
        rb.validate()

        for part in xrange(rb.parts):
            counts = dict(zone=defaultdict(lambda: 0),
                          dev_id=defaultdict(lambda: 0))
            for replica in xrange(rb.replicas):
                dev = rb.devs[rb._replica2part2dev[replica][part]]
                counts['zone'][dev['zone']] += 1
                counts['dev_id'][dev['id']] += 1

            self.assertEquals({0: 2, 1: 2, 2: 2}, dict(counts['zone']))
            self.assertEquals({0: 1, 1: 1, 2: 1, 3: 1, 4: 1, 5: 1},
                              dict(counts['dev_id']))

    def test_multitier_part_moves_with_0_min_part_hours(self):
        rb = ring.RingBuilder(8, 3, 0)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.rebalance()
        rb.validate()

        # min_part_hours is 0, so we're clear to move 2 replicas to
        # new devs
        rb.add_dev({'id': 1, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdb1'})
        rb.add_dev({'id': 2, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdc1'})
        rb.rebalance()
        rb.validate()

        for part in xrange(rb.parts):
            devs = set()
            for replica in xrange(rb.replicas):
                devs.add(rb._replica2part2dev[replica][part])

            if len(devs) != 3:
                raise AssertionError(
                    "Partition %d not on 3 devs (got %r)" % (part, devs))

    def test_multitier_part_moves_with_positive_min_part_hours(self):
        rb = ring.RingBuilder(8, 3, 99)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.rebalance()
        rb.validate()

        # min_part_hours is >0, so we'll only be able to move 1
        # replica to a new home
        rb.add_dev({'id': 1, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdb1'})
        rb.add_dev({'id': 2, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdc1'})
        rb.pretend_min_part_hours_passed()
        rb.rebalance()
        rb.validate()

        for part in xrange(rb.parts):
            devs = set()
            for replica in xrange(rb.replicas):
                devs.add(rb._replica2part2dev[replica][part])

            if len(devs) != 2:
                raise AssertionError(
                    "Partition %d not on 2 devs (got %r)" % (part, devs))

    def test_multitier_dont_move_too_many_replicas(self):
        rb = ring.RingBuilder(8, 3, 0)
        # there'll be at least one replica in z0 and z1
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdb1'})
        rb.rebalance()
        rb.validate()

        # only 1 replica should move
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdd1'})
        rb.add_dev({'id': 3, 'zone': 3, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sde1'})
        rb.add_dev({'id': 4, 'zone': 4, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sdf1'})
        rb.rebalance()
        rb.validate()

        for part in xrange(rb.parts):
            zones = set()
            for replica in xrange(rb.replicas):
                zones.add(rb.devs[rb._replica2part2dev[replica][part]]['zone'])

            if len(zones) != 3:
                raise AssertionError(
                    "Partition %d not in 3 zones (got %r)" % (part, zones))
            if 0 not in zones or 1 not in zones:
                raise AssertionError(
                    "Partition %d not in zones 0 and 1 (got %r)" %
                    (part, zones))

    def test_rerebalance(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sda1'})
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts, {0: 256, 1: 256, 2: 256})
        rb.add_dev({'id': 3, 'zone': 3, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10003, 'device': 'sda1'})
        rb.pretend_min_part_hours_passed()
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts, {0: 192, 1: 192, 2: 192, 3: 192})
        rb.set_dev_weight(3, 100)
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts[3], 256)

    def test_add_rebalance_add_rebalance_delete_rebalance(self):
        """ Test for https://bugs.launchpad.net/swift/+bug/845952 """
        # min_part of 0 to allow for rapid rebalancing
        rb = ring.RingBuilder(8, 3, 0)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sda1'})

        rb.rebalance()

        rb.add_dev({'id': 3, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10003, 'device': 'sda1'})
        rb.add_dev({'id': 4, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10004, 'device': 'sda1'})
        rb.add_dev({'id': 5, 'zone': 2, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10005, 'device': 'sda1'})

        rb.rebalance()

        rb.remove_dev(1)

        rb.rebalance()

    def test_validate(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',
                    'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'zone': 2, 'weight': 2, 'ip': '127.0.0.1',
                    'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'zone': 3, 'weight': 2, 'ip': '127.0.0.1',
                    'port': 10003, 'device': 'sda1'})
        rb.rebalance()
        r = rb.get_ring()
        counts = {}
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                counts[dev_id] = counts.get(dev_id, 0) + 1
        self.assertEquals(counts, {0: 128, 1: 128, 2: 256, 3: 256})

        dev_usage, worst = rb.validate()
        self.assert_(dev_usage is None)
        self.assert_(worst is None)

        dev_usage, worst = rb.validate(stats=True)
        self.assertEquals(list(dev_usage), [128, 128, 256, 256])
        self.assertEquals(int(worst), 0)

        rb.set_dev_weight(2, 0)
        rb.rebalance()
        self.assertEquals(rb.validate(stats=True)[1], 999.99)

        # Test not all partitions doubly accounted for
        rb.devs[1]['parts'] -= 1
        self.assertRaises(exceptions.RingValidationError, rb.validate)
        rb.devs[1]['parts'] += 1

        # Test partition on nonexistent device
        rb.pretend_min_part_hours_passed()
        orig_dev_id = rb._replica2part2dev[0][0]
        rb._replica2part2dev[0][0] = len(rb.devs)
        self.assertRaises(exceptions.RingValidationError, rb.validate)
        rb._replica2part2dev[0][0] = orig_dev_id

        # Tests that validate can handle 'holes' in .devs
        rb.remove_dev(2)
        rb.pretend_min_part_hours_passed()
        rb.rebalance()
        rb.validate(stats=True)

        # Test partition assigned to a hole
        if rb.devs[2]:
            rb.remove_dev(2)
        rb.pretend_min_part_hours_passed()
        orig_dev_id = rb._replica2part2dev[0][0]
        rb._replica2part2dev[0][0] = 2
        self.assertRaises(exceptions.RingValidationError, rb.validate)
        rb._replica2part2dev[0][0] = orig_dev_id

        # Validate that zero weight devices with no partitions don't count on
        # the 'worst' value.
        self.assertNotEquals(rb.validate(stats=True)[1], 999.99)
        rb.add_dev({'id': 4, 'zone': 0, 'weight': 0, 'ip': '127.0.0.1',
                    'port': 10004, 'device': 'sda1'})
        rb.pretend_min_part_hours_passed()
        rb.rebalance()
        self.assertNotEquals(rb.validate(stats=True)[1], 999.99)


if __name__ == '__main__':
    unittest.main()