# Copyright (c) 2010-2012 OpenStack Foundation
#
# 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 errno
import mock
import operator
import os
import unittest
import cPickle as pickle
from collections import defaultdict
from math import ceil
from tempfile import mkdtemp
from shutil import rmtree

from swift.common import exceptions
from swift.common import ring
from swift.common.ring.builder import MAX_BALANCE


class TestRingBuilder(unittest.TestCase):

    def setUp(self):
        self.testdir = mkdtemp()

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

    def _get_population_by_region(self, builder):
        """
        Returns a dictionary mapping region to number of partitions in that
        region.
        """
        population_by_region = defaultdict(int)
        r = builder.get_ring()
        for part2dev_id in r._replica2part2dev_id:
            for dev_id in part2dev_id:
                dev = r.devs[dev_id]
                population_by_region[dev['region']] += 1
        return dict(population_by_region.items())

    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_overlarge_part_powers(self):
        ring.RingBuilder(32, 3, 1)  # passes by not crashing
        self.assertRaises(ValueError, ring.RingBuilder, 33, 3, 1)

    def test_insufficient_replicas(self):
        ring.RingBuilder(8, 1.0, 1)  # passes by not crashing
        self.assertRaises(ValueError, ring.RingBuilder, 8, 0.999, 1)

    def test_negative_min_part_hours(self):
        ring.RingBuilder(8, 3, 0)  # passes by not crashing
        self.assertRaises(ValueError, ring.RingBuilder, 8, 3, -1)

    def test_get_ring(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'region': 0, '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_rebalance_with_seed(self):
        devs = [(0, 10000), (1, 10001), (2, 10002), (1, 10003)]
        ring_builders = []
        for n in range(3):
            rb = ring.RingBuilder(8, 3, 1)
            for idx, (zone, port) in enumerate(devs):
                rb.add_dev({'id': idx, 'region': 0, 'zone': zone, 'weight': 1,
                            'ip': '127.0.0.1', 'port': port, 'device': 'sda1'})
            ring_builders.append(rb)

        rb0 = ring_builders[0]
        rb1 = ring_builders[1]
        rb2 = ring_builders[2]

        r0 = rb0.get_ring()
        self.assertTrue(rb0.get_ring() is r0)

        rb0.rebalance()  # NO SEED
        rb1.rebalance(seed=10)
        rb2.rebalance(seed=10)

        r1 = rb1.get_ring()
        r2 = rb2.get_ring()

        self.assertFalse(rb0.get_ring() is r0)
        self.assertNotEquals(r0.to_dict(), r1.to_dict())
        self.assertEquals(r1.to_dict(), r2.to_dict())

    def test_rebalance_part_on_deleted_other_part_on_drained(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10003, 'device': 'sda1'})
        rb.add_dev({'id': 4, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10004, 'device': 'sda1'})
        rb.add_dev({'id': 5, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10005, 'device': 'sda1'})

        rb.rebalance(seed=1)
        # We want a partition where 1 replica is on a removed device, 1
        # replica is on a 0-weight device, and 1 on a normal device. To
        # guarantee we have one, we see where partition 123 is, then
        # manipulate its devices accordingly.
        zero_weight_dev_id = rb._replica2part2dev[1][123]
        delete_dev_id = rb._replica2part2dev[2][123]

        rb.set_dev_weight(zero_weight_dev_id, 0.0)
        rb.remove_dev(delete_dev_id)
        rb.rebalance()

    def test_set_replicas(self):
        rb = ring.RingBuilder(8, 3.2, 1)
        rb.devs_changed = False
        rb.set_replicas(3.25)
        self.assertTrue(rb.devs_changed)

        rb.devs_changed = False
        rb.set_replicas(3.2500001)
        self.assertFalse(rb.devs_changed)

    def test_add_dev(self):
        rb = ring.RingBuilder(8, 3, 1)
        dev = {'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
               'ip': '127.0.0.1', 'port': 10000}
        dev_id = rb.add_dev(dev)
        self.assertRaises(exceptions.DuplicateDeviceError, rb.add_dev, dev)
        self.assertEqual(dev_id, 0)
        rb = ring.RingBuilder(8, 3, 1)
        # test add new dev with no id
        dev_id = rb.add_dev({'zone': 0, 'region': 1, 'weight': 1,
                             'ip': '127.0.0.1', 'port': 6000})
        self.assertEquals(rb.devs[0]['id'], 0)
        self.assertEqual(dev_id, 0)
        #test add another dev with no id
        dev_id = rb.add_dev({'zone': 3, 'region': 2, 'weight': 1,
                             'ip': '127.0.0.1', 'port': 6000})
        self.assertEquals(rb.devs[1]['id'], 1)
        self.assertEqual(dev_id, 1)

    def test_set_dev_weight(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 0.5,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 0, 'weight': 0.5,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'region': 0, '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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'region': 0, '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, 'region': 0, 'zone': 1})
        rb.add_dev({'id': 1, 'device': 'd1', 'ip': '10.0.0.2',
                    'port': 6002, 'weight': 1000.0, 'region': 0, 'zone': 2})
        rb.add_dev({'id': 2, 'device': 'd2', 'ip': '10.0.0.3',
                    'port': 6002, 'weight': 1000.0, 'region': 0, 'zone': 3})
        rb.add_dev({'id': 3, 'device': 'd3', 'ip': '10.0.0.1',
                    'port': 6002, 'weight': 1000.0, 'region': 0, 'zone': 1})
        rb.add_dev({'id': 4, 'device': 'd4', 'ip': '10.0.0.2',
                    'port': 6002, 'weight': 1000.0, 'region': 0, 'zone': 2})
        rb.add_dev({'id': 5, 'device': 'd5', 'ip': '10.0.0.3',
                    'port': 6002, 'weight': 1000.0, 'region': 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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sda1'})
        rb.rebalance()
        rb.add_dev({'id': 3, 'region': 0, '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_initial_balance(self):
        # 2 boxes, 2 drives each in zone 1
        # 1 box, 2 drives in zone 2
        #
        # This is balanceable, but there used to be some nondeterminism in
        # rebalance() that would sometimes give you an imbalanced ring.
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,
                    'ip': '10.1.1.1', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,
                    'ip': '10.1.1.1', 'port': 10000, 'device': 'sdb'})

        rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,
                    'ip': '10.1.1.2', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'region': 1, 'zone': 1, 'weight': 4000.0,
                    'ip': '10.1.1.2', 'port': 10000, 'device': 'sdb'})

        rb.add_dev({'region': 1, 'zone': 2, 'weight': 4000.0,
                    'ip': '10.1.1.3', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'region': 1, 'zone': 2, 'weight': 4000.0,
                    'ip': '10.1.1.3', 'port': 10000, 'device': 'sdb'})

        _, balance = rb.rebalance(seed=2)

        # maybe not *perfect*, but should be close
        self.assert_(balance <= 1)

    def test_multitier_partial(self):
        # Multitier test, nothing full
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdb'})
        rb.add_dev({'id': 2, 'region': 2, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdc'})
        rb.add_dev({'id': 3, 'region': 3, 'zone': 3, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdd'})

        rb.rebalance()
        rb.validate()

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

            if any(c > 1 for c in counts['region'].values()):
                raise AssertionError(
                    "Partition %d not evenly region-distributed (got %r)" %
                    (part, counts['region']))
            if any(c > 1 for c in counts['zone'].values()):
                raise AssertionError(
                    "Partition %d not evenly zone-distributed (got %r)" %
                    (part, counts['zone']))

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

        rb.add_dev({'id': 3, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sdd'})
        rb.add_dev({'id': 4, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sde'})
        rb.add_dev({'id': 5, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sdf'})

        rb.add_dev({'id': 6, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sdg'})
        rb.add_dev({'id': 7, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sdh'})
        rb.add_dev({'id': 8, 'region': 0, '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(int))
            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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdb'})

        rb.add_dev({'id': 2, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdc'})
        rb.add_dev({'id': 3, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sdd'})

        rb.add_dev({'id': 4, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sde'})
        rb.add_dev({'id': 5, 'region': 0, '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(int))
            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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdb'})

        rb.add_dev({'id': 2, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdc'})
        rb.add_dev({'id': 3, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sdd'})

        rb.add_dev({'id': 4, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sde'})
        rb.add_dev({'id': 5, 'region': 0, '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(int))
            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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdb'})
        rb.add_dev({'id': 2, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdc'})

        rb.rebalance()
        rb.validate()

        rb.add_dev({'id': 3, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdd'})
        rb.add_dev({'id': 4, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sde'})
        rb.add_dev({'id': 5, 'region': 0, '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(int),
                          dev_id=defaultdict(int))
            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, 'region': 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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdb1'})
        rb.add_dev({'id': 2, 'region': 0, '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, 'region': 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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdb1'})
        rb.add_dev({'id': 2, 'region': 0, '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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, '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, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdd1'})
        rb.add_dev({'id': 3, 'region': 0, 'zone': 3, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sde1'})
        rb.add_dev({'id': 4, 'region': 0, '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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 0, '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, 'region': 0, '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, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sda1'})

        rb.rebalance()

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

        rb.rebalance()

        rb.remove_dev(1)

        rb.rebalance()

    def test_region_fullness_with_balanceable_ring(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})

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

        rb.add_dev({'id': 4, 'region': 2, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10005, 'device': 'sda1'})
        rb.add_dev({'id': 5, 'region': 2, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10006, 'device': 'sda1'})

        rb.add_dev({'id': 6, 'region': 3, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10007, 'device': 'sda1'})
        rb.add_dev({'id': 7, 'region': 3, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10008, 'device': 'sda1'})
        rb.rebalance(seed=2)

        population_by_region = self._get_population_by_region(rb)
        self.assertEquals(population_by_region,
                          {0: 192, 1: 192, 2: 192, 3: 192})

    def test_region_fullness_with_unbalanceable_ring(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 2,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 2,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})

        rb.add_dev({'id': 2, 'region': 1, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10003, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'region': 1, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10004, 'device': 'sda1'})
        rb.rebalance(seed=2)

        population_by_region = self._get_population_by_region(rb)
        self.assertEquals(population_by_region, {0: 512, 1: 256})

    def test_adding_region_slowly_with_unbalanceable_ring(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 2,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 2,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.rebalance(seed=2)

        rb.add_dev({'id': 2, 'region': 1, 'zone': 0, 'weight': 0.25,
                    'ip': '127.0.0.1', 'port': 10003, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'region': 1, 'zone': 1, 'weight': 0.25,
                    'ip': '127.0.0.1', 'port': 10004, 'device': 'sda1'})
        rb.pretend_min_part_hours_passed()
        changed_parts, _balance = rb.rebalance(seed=2)

        # there's not enough room in r1 for every partition to have a replica
        # in it, so only 86 assignments occur in r1 (that's ~1/5 of the total,
        # since r1 has 1/5 of the weight).
        population_by_region = self._get_population_by_region(rb)
        self.assertEquals(population_by_region, {0: 682, 1: 86})

        self.assertEqual(87, changed_parts)

        # and since there's not enough room, subsequent rebalances will not
        # cause additional assignments to r1
        rb.pretend_min_part_hours_passed()
        rb.rebalance(seed=2)
        population_by_region = self._get_population_by_region(rb)
        self.assertEquals(population_by_region, {0: 682, 1: 86})

        # after you add more weight, more partition assignments move
        rb.set_dev_weight(2, 0.5)
        rb.set_dev_weight(3, 0.5)
        rb.pretend_min_part_hours_passed()
        rb.rebalance(seed=2)
        population_by_region = self._get_population_by_region(rb)
        self.assertEquals(population_by_region, {0: 614, 1: 154})

        rb.set_dev_weight(2, 1.0)
        rb.set_dev_weight(3, 1.0)
        rb.pretend_min_part_hours_passed()
        rb.rebalance(seed=2)
        population_by_region = self._get_population_by_region(rb)
        self.assertEquals(population_by_region, {0: 512, 1: 256})

    def test_avoid_tier_change_new_region(self):
        rb = ring.RingBuilder(8, 3, 1)
        for i in range(5):
            rb.add_dev({'id': i, 'region': 0, 'zone': 0, 'weight': 100,
                        'ip': '127.0.0.1', 'port': i, 'device': 'sda1'})
        rb.rebalance(seed=2)

        # Add a new device in new region to a balanced ring
        rb.add_dev({'id': 5, 'region': 1, 'zone': 0, 'weight': 0,
                    'ip': '127.0.0.5', 'port': 10000, 'device': 'sda1'})

        # Increase the weight of region 1 slowly
        moved_partitions = []
        for weight in range(0, 101, 10):
            rb.set_dev_weight(5, weight)
            rb.pretend_min_part_hours_passed()
            changed_parts, _balance = rb.rebalance(seed=2)
            moved_partitions.append(changed_parts)
            # Ensure that the second region has enough partitions
            # Otherwise there will be replicas at risk
            min_parts_for_r1 = ceil(weight / (500.0 + weight) * 768)
            parts_for_r1 = self._get_population_by_region(rb).get(1, 0)
            self.assertEqual(min_parts_for_r1, parts_for_r1)

        # Number of partitions moved on each rebalance
        # 10/510 * 768 ~ 15.06 -> move at least 15 partitions in first step
        ref = [0, 17, 16, 16, 14, 15, 13, 13, 12, 12, 14]
        self.assertEqual(ref, moved_partitions)

    def test_set_replicas_increase(self):
        rb = ring.RingBuilder(8, 2, 0)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.rebalance()
        rb.validate()

        rb.replicas = 2.1
        rb.rebalance()
        rb.validate()

        self.assertEqual([len(p2d) for p2d in rb._replica2part2dev],
                         [256, 256, 25])

        rb.replicas = 2.2
        rb.rebalance()
        rb.validate()
        self.assertEqual([len(p2d) for p2d in rb._replica2part2dev],
                         [256, 256, 51])

    def test_set_replicas_decrease(self):
        rb = ring.RingBuilder(4, 5, 0)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.rebalance()
        rb.validate()

        rb.replicas = 4.9
        rb.rebalance()
        rb.validate()

        self.assertEqual([len(p2d) for p2d in rb._replica2part2dev],
                         [16, 16, 16, 16, 14])

        # cross a couple of integer thresholds (4 and 3)
        rb.replicas = 2.5
        rb.rebalance()
        rb.validate()

        self.assertEqual([len(p2d) for p2d in rb._replica2part2dev],
                         [16, 16, 8])

    def test_fractional_replicas_rebalance(self):
        rb = ring.RingBuilder(8, 2.5, 0)
        rb.add_dev({'id': 0, 'region': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.rebalance()  # passes by not crashing
        rb.validate()   # also passes by not crashing
        self.assertEqual([len(p2d) for p2d in rb._replica2part2dev],
                         [256, 256, 128])

    def test_create_add_dev_add_replica_rebalance(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'region': 0, 'zone': 0, 'weight': 3,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda'})
        rb.set_replicas(4)
        rb.rebalance()  # this would crash since parts_wanted was not set
        rb.validate()

    def test_add_replicas_then_rebalance_respects_weight(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'region': 0, 'zone': 0, 'weight': 3,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda'})
        rb.add_dev({'id': 1, 'region': 0, 'region': 0, 'zone': 0, 'weight': 3,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdb'})
        rb.add_dev({'id': 2, 'region': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdc'})
        rb.add_dev({'id': 3, 'region': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdd'})

        rb.add_dev({'id': 4, 'region': 0, 'region': 0, 'zone': 1, 'weight': 3,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sde'})
        rb.add_dev({'id': 5, 'region': 0, 'region': 0, 'zone': 1, 'weight': 3,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdf'})
        rb.add_dev({'id': 6, 'region': 0, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdg'})
        rb.add_dev({'id': 7, 'region': 0, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdh'})

        rb.add_dev({'id': 8, 'region': 0, 'region': 0, 'zone': 2, 'weight': 3,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdi'})
        rb.add_dev({'id': 9, 'region': 0, 'region': 0, 'zone': 2, 'weight': 3,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdj'})
        rb.add_dev({'id': 10, 'region': 0, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdk'})
        rb.add_dev({'id': 11, 'region': 0, 'region': 0, 'zone': 2, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sdl'})

        rb.rebalance(seed=1)

        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: 96, 1: 96,
                                   2: 32, 3: 32,
                                   4: 96, 5: 96,
                                   6: 32, 7: 32,
                                   8: 96, 9: 96,
                                   10: 32, 11: 32})

        rb.replicas *= 2
        rb.rebalance(seed=1)

        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: 64, 3: 64,
                                   4: 192, 5: 192,
                                   6: 64, 7: 64,
                                   8: 192, 9: 192,
                                   10: 64, 11: 64})

    def test_load(self):
        rb = ring.RingBuilder(8, 3, 1)
        devs = [{'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                 'ip': '127.0.0.0', 'port': 10000, 'device': 'sda1',
                 'meta': 'meta0'},
                {'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                 'ip': '127.0.0.1', 'port': 10001, 'device': 'sdb1',
                 'meta': 'meta1'},
                {'id': 2, 'region': 0, 'zone': 2, 'weight': 2,
                 'ip': '127.0.0.2', 'port': 10002, 'device': 'sdc1',
                 'meta': 'meta2'},
                {'id': 3, 'region': 0, 'zone': 3, 'weight': 2,
                 'ip': '127.0.0.3', 'port': 10003, 'device': 'sdd1'}]
        for d in devs:
            rb.add_dev(d)
        rb.rebalance()

        real_pickle = pickle.load
        fake_open = mock.mock_open()

        io_error_not_found = IOError()
        io_error_not_found.errno = errno.ENOENT

        io_error_no_perm = IOError()
        io_error_no_perm.errno = errno.EPERM

        io_error_generic = IOError()
        io_error_generic.errno = errno.EOPNOTSUPP
        try:
            #test a legit builder
            fake_pickle = mock.Mock(return_value=rb)
            pickle.load = fake_pickle
            builder = ring.RingBuilder.load('fake.builder', open=fake_open)
            self.assertEquals(fake_pickle.call_count, 1)
            fake_open.assert_has_calls([mock.call('fake.builder', 'rb')])
            self.assertEquals(builder, rb)
            fake_pickle.reset_mock()

            #test old style builder
            fake_pickle.return_value = rb.to_dict()
            pickle.load = fake_pickle
            builder = ring.RingBuilder.load('fake.builder', open=fake_open)
            fake_open.assert_has_calls([mock.call('fake.builder', 'rb')])
            self.assertEquals(builder.devs, rb.devs)
            fake_pickle.reset_mock()

            #test old devs but no meta
            no_meta_builder = rb
            for dev in no_meta_builder.devs:
                del(dev['meta'])
            fake_pickle.return_value = no_meta_builder
            pickle.load = fake_pickle
            builder = ring.RingBuilder.load('fake.builder', open=fake_open)
            fake_open.assert_has_calls([mock.call('fake.builder', 'rb')])
            self.assertEquals(builder.devs, rb.devs)

            #test an empty builder
            fake_pickle.side_effect = EOFError
            pickle.load = fake_pickle
            self.assertRaises(exceptions.UnPicklingError,
                              ring.RingBuilder.load, 'fake.builder',
                              open=fake_open)

            #test a corrupted builder
            fake_pickle.side_effect = pickle.UnpicklingError
            pickle.load = fake_pickle
            self.assertRaises(exceptions.UnPicklingError,
                              ring.RingBuilder.load, 'fake.builder',
                              open=fake_open)

            #test some error
            fake_pickle.side_effect = AttributeError
            pickle.load = fake_pickle
            self.assertRaises(exceptions.UnPicklingError,
                              ring.RingBuilder.load, 'fake.builder',
                              open=fake_open)
        finally:
            pickle.load = real_pickle

        #test non existent builder file
        fake_open.side_effect = io_error_not_found
        self.assertRaises(exceptions.FileNotFoundError,
                          ring.RingBuilder.load, 'fake.builder',
                          open=fake_open)

        #test non accessible builder file
        fake_open.side_effect = io_error_no_perm
        self.assertRaises(exceptions.PermissionError,
                          ring.RingBuilder.load, 'fake.builder',
                          open=fake_open)

        #test an error other then ENOENT and ENOPERM
        fake_open.side_effect = io_error_generic
        self.assertRaises(IOError,
                          ring.RingBuilder.load, 'fake.builder',
                          open=fake_open)

    def test_save_load(self):
        rb = ring.RingBuilder(8, 3, 1)
        devs = [{'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                 'ip': '127.0.0.0', 'port': 10000,
                 'replication_ip': '127.0.0.0', 'replication_port': 10000,
                 'device': 'sda1', 'meta': 'meta0'},
                {'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                 'ip': '127.0.0.1', 'port': 10001,
                 'replication_ip': '127.0.0.1', 'replication_port': 10001,
                 'device': 'sdb1', 'meta': 'meta1'},
                {'id': 2, 'region': 0, 'zone': 2, 'weight': 2,
                 'ip': '127.0.0.2', 'port': 10002,
                 'replication_ip': '127.0.0.2', 'replication_port': 10002,
                 'device': 'sdc1', 'meta': 'meta2'},
                {'id': 3, 'region': 0, 'zone': 3, 'weight': 2,
                 'ip': '127.0.0.3', 'port': 10003,
                 'replication_ip': '127.0.0.3', 'replication_port': 10003,
                 'device': 'sdd1', 'meta': ''}]
        for d in devs:
            rb.add_dev(d)
        rb.rebalance()
        builder_file = os.path.join(self.testdir, 'test_save.builder')
        rb.save(builder_file)
        loaded_rb = ring.RingBuilder.load(builder_file)
        self.maxDiff = None
        self.assertEquals(loaded_rb.to_dict(), rb.to_dict())

    @mock.patch('__builtin__.open', autospec=True)
    @mock.patch('swift.common.ring.builder.pickle.dump', autospec=True)
    def test_save(self, mock_pickle_dump, mock_open):
        mock_open.return_value = mock_fh = mock.MagicMock()
        rb = ring.RingBuilder(8, 3, 1)
        devs = [{'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                 'ip': '127.0.0.0', 'port': 10000, 'device': 'sda1',
                 'meta': 'meta0'},
                {'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                 'ip': '127.0.0.1', 'port': 10001, 'device': 'sdb1',
                 'meta': 'meta1'},
                {'id': 2, 'region': 0, 'zone': 2, 'weight': 2,
                 'ip': '127.0.0.2', 'port': 10002, 'device': 'sdc1',
                 'meta': 'meta2'},
                {'id': 3, 'region': 0, 'zone': 3, 'weight': 2,
                 'ip': '127.0.0.3', 'port': 10003, 'device': 'sdd1'}]
        for d in devs:
            rb.add_dev(d)
        rb.rebalance()
        rb.save('some.builder')
        mock_open.assert_called_once_with('some.builder', 'wb')
        mock_pickle_dump.assert_called_once_with(rb.to_dict(),
                                                 mock_fh.__enter__(),
                                                 protocol=2)

    def test_search_devs(self):
        rb = ring.RingBuilder(8, 3, 1)
        devs = [{'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                 'ip': '127.0.0.0', 'port': 10000, 'device': 'sda1',
                 'meta': 'meta0'},
                {'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                 'ip': '127.0.0.1', 'port': 10001, 'device': 'sdb1',
                 'meta': 'meta1'},
                {'id': 2, 'region': 1, 'zone': 2, 'weight': 2,
                 'ip': '127.0.0.2', 'port': 10002, 'device': 'sdc1',
                 'meta': 'meta2'},
                {'id': 3, 'region': 1, 'zone': 3, 'weight': 2,
                 'ip': '127.0.0.3', 'port': 10003, 'device': 'sdd1',
                 'meta': 'meta3'},
                {'id': 4, 'region': 2, 'zone': 4, 'weight': 1,
                 'ip': '127.0.0.4', 'port': 10004, 'device': 'sde1',
                 'meta': 'meta4', 'replication_ip': '127.0.0.10',
                 'replication_port': 20000},
                {'id': 5, 'region': 2, 'zone': 5, 'weight': 2,
                 'ip': '127.0.0.5', 'port': 10005, 'device': 'sdf1',
                 'meta': 'meta5', 'replication_ip': '127.0.0.11',
                 'replication_port': 20001},
                {'id': 6, 'region': 2, 'zone': 6, 'weight': 2,
                 'ip': '127.0.0.6', 'port': 10006, 'device': 'sdg1',
                 'meta': 'meta6', 'replication_ip': '127.0.0.12',
                 'replication_port': 20002}]
        for d in devs:
            rb.add_dev(d)
        rb.rebalance()
        res = rb.search_devs({'region': 0})
        self.assertEquals(res, [devs[0], devs[1]])
        res = rb.search_devs({'region': 1})
        self.assertEquals(res, [devs[2], devs[3]])
        res = rb.search_devs({'region': 1, 'zone': 2})
        self.assertEquals(res, [devs[2]])
        res = rb.search_devs({'id': 1})
        self.assertEquals(res, [devs[1]])
        res = rb.search_devs({'zone': 1})
        self.assertEquals(res, [devs[1]])
        res = rb.search_devs({'ip': '127.0.0.1'})
        self.assertEquals(res, [devs[1]])
        res = rb.search_devs({'ip': '127.0.0.1', 'port': 10001})
        self.assertEquals(res, [devs[1]])
        res = rb.search_devs({'port': 10001})
        self.assertEquals(res, [devs[1]])
        res = rb.search_devs({'replication_ip': '127.0.0.10'})
        self.assertEquals(res, [devs[4]])
        res = rb.search_devs({'replication_ip': '127.0.0.10',
                              'replication_port': 20000})
        self.assertEquals(res, [devs[4]])
        res = rb.search_devs({'replication_port': 20000})
        self.assertEquals(res, [devs[4]])
        res = rb.search_devs({'device': 'sdb1'})
        self.assertEquals(res, [devs[1]])
        res = rb.search_devs({'meta': 'meta1'})
        self.assertEquals(res, [devs[1]])

    def test_validate(self):
        rb = ring.RingBuilder(8, 3, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.add_dev({'id': 2, 'region': 0, 'zone': 2, 'weight': 2,
                    'ip': '127.0.0.1', 'port': 10002, 'device': 'sda1'})
        rb.add_dev({'id': 3, 'region': 0, 'zone': 3, 'weight': 2,
                    'ip': '127.0.0.1', 'port': 10003, 'device': 'sda1'})

        # Degenerate case: devices added but not rebalanced yet
        self.assertRaises(exceptions.RingValidationError, rb.validate)

        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], MAX_BALANCE)

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

        # Test non-numeric port
        rb.devs[1]['port'] = '10001'
        self.assertRaises(exceptions.RingValidationError, rb.validate)
        rb.devs[1]['port'] = 10001

        # 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], MAX_BALANCE)
        rb.add_dev({'id': 4, 'region': 0, '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], MAX_BALANCE)

    def test_get_part_devices(self):
        rb = ring.RingBuilder(8, 3, 1)
        self.assertEqual(rb.get_part_devices(0), [])

        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.rebalance()

        part_devs = sorted(rb.get_part_devices(0),
                           key=operator.itemgetter('id'))
        self.assertEqual(part_devs, [rb.devs[0], rb.devs[1]])

    def test_get_part_devices_partial_replicas(self):
        rb = ring.RingBuilder(8, 2.5, 1)
        rb.add_dev({'id': 0, 'region': 0, 'zone': 0, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10000, 'device': 'sda1'})
        rb.add_dev({'id': 1, 'region': 0, 'zone': 1, 'weight': 1,
                    'ip': '127.0.0.1', 'port': 10001, 'device': 'sda1'})
        rb.rebalance()

        # note: partition 255 will only have 2 replicas
        part_devs = sorted(rb.get_part_devices(255),
                           key=operator.itemgetter('id'))
        self.assertEqual(part_devs, [rb.devs[0], rb.devs[1]])


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