918a5055ff
Using floats turned out to be a bad idea, as it broke subtely if the needed precision was too large. This PR replaces the implementation with one that uses fractions and stores them in the database as two integers.
303 lines
8.9 KiB
Python
303 lines
8.9 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2018 New Vector Ltd
|
|
#
|
|
# 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.
|
|
|
|
from twisted.internet import defer
|
|
|
|
import itertools
|
|
import random
|
|
import tests.unittest
|
|
import tests.utils
|
|
|
|
from fractions import Fraction
|
|
|
|
from synapse.storage.chunk_ordered_table import (
|
|
ChunkDBOrderedListStore, find_farey_terms, get_fraction_in_range,
|
|
)
|
|
|
|
|
|
class ChunkLinearizerStoreTestCase(tests.unittest.TestCase):
|
|
"""Tests to ensure that the ordering and rebalancing functions of
|
|
ChunkDBOrderedListStore work as expected.
|
|
"""
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
super(ChunkLinearizerStoreTestCase, self).__init__(*args, **kwargs)
|
|
|
|
@defer.inlineCallbacks
|
|
def setUp(self):
|
|
hs = yield tests.utils.setup_test_homeserver()
|
|
self.store = hs.get_datastore()
|
|
self.clock = hs.get_clock()
|
|
|
|
@defer.inlineCallbacks
|
|
def test_simple_insert_fetch(self):
|
|
room_id = "foo_room1"
|
|
|
|
def test_txn(txn):
|
|
table = ChunkDBOrderedListStore(
|
|
txn, room_id, self.clock,
|
|
self.store.database_engine,
|
|
5, 100,
|
|
)
|
|
|
|
table.add_node("A")
|
|
table._insert_after("B", "A")
|
|
table._insert_before("C", "A")
|
|
table._insert_after("D", "A")
|
|
|
|
sql = """
|
|
SELECT chunk_id, numerator, denominator FROM chunk_linearized
|
|
WHERE room_id = ?
|
|
"""
|
|
txn.execute(sql, (room_id,))
|
|
|
|
ordered = sorted([(Fraction(n, d), r) for r, n, d in txn])
|
|
ordered = [c for _, c in ordered]
|
|
|
|
self.assertEqual(["C", "A", "D", "B"], ordered)
|
|
|
|
yield self.store.runInteraction("test", test_txn)
|
|
|
|
@defer.inlineCallbacks
|
|
def test_many_insert_fetch(self):
|
|
room_id = "foo_room2"
|
|
|
|
def test_txn(txn):
|
|
table = ChunkDBOrderedListStore(
|
|
txn, room_id, self.clock,
|
|
self.store.database_engine,
|
|
5, 100,
|
|
)
|
|
|
|
nodes = [(i, "node_%d" % (i,)) for i in xrange(1, 1000)]
|
|
expected = [n for _, n in nodes]
|
|
|
|
already_inserted = []
|
|
|
|
random.shuffle(nodes)
|
|
while nodes:
|
|
i, node_id = nodes.pop()
|
|
if not already_inserted:
|
|
table.add_node(node_id)
|
|
else:
|
|
for j, target_id in already_inserted:
|
|
if j > i:
|
|
break
|
|
|
|
if j < i:
|
|
table._insert_after(node_id, target_id)
|
|
else:
|
|
table._insert_before(node_id, target_id)
|
|
|
|
already_inserted.append((i, node_id))
|
|
already_inserted.sort()
|
|
|
|
sql = """
|
|
SELECT chunk_id, numerator, denominator FROM chunk_linearized
|
|
WHERE room_id = ?
|
|
"""
|
|
txn.execute(sql, (room_id,))
|
|
|
|
ordered = sorted([(Fraction(n, d), r) for r, n, d in txn])
|
|
ordered = [c for _, c in ordered]
|
|
|
|
self.assertEqual(expected, ordered)
|
|
|
|
yield self.store.runInteraction("test", test_txn)
|
|
|
|
@defer.inlineCallbacks
|
|
def test_prepend_and_append(self):
|
|
room_id = "foo_room3"
|
|
|
|
def test_txn(txn):
|
|
table = ChunkDBOrderedListStore(
|
|
txn, room_id, self.clock,
|
|
self.store.database_engine,
|
|
5, 1000,
|
|
)
|
|
|
|
table.add_node("a")
|
|
|
|
expected = ["a"]
|
|
|
|
for i in xrange(1, 1000):
|
|
node_id = "node_id_before_%d" % i
|
|
table._insert_before(node_id, expected[0])
|
|
expected.insert(0, node_id)
|
|
|
|
for i in xrange(1, 1000):
|
|
node_id = "node_id_after_%d" % i
|
|
table._insert_after(node_id, expected[-1])
|
|
expected.append(node_id)
|
|
|
|
sql = """
|
|
SELECT chunk_id, numerator, denominator FROM chunk_linearized
|
|
WHERE room_id = ?
|
|
"""
|
|
txn.execute(sql, (room_id,))
|
|
|
|
ordered = sorted([(Fraction(n, d), r) for r, n, d in txn])
|
|
ordered = [c for _, c in ordered]
|
|
|
|
self.assertEqual(expected, ordered)
|
|
|
|
yield self.store.runInteraction("test", test_txn)
|
|
|
|
@defer.inlineCallbacks
|
|
def test_worst_case(self):
|
|
room_id = "foo_room3"
|
|
|
|
def test_txn(txn):
|
|
table = ChunkDBOrderedListStore(
|
|
txn, room_id, self.clock,
|
|
self.store.database_engine,
|
|
5, 100,
|
|
)
|
|
|
|
table.add_node("a")
|
|
|
|
prev_node = "a"
|
|
|
|
expected_prefix = ["a"]
|
|
expected_suffix = []
|
|
|
|
for i in xrange(1, 100):
|
|
node_id = "node_id_%d" % i
|
|
if i % 2 == 0:
|
|
table._insert_before(node_id, prev_node)
|
|
expected_prefix.append(node_id)
|
|
else:
|
|
table._insert_after(node_id, prev_node)
|
|
expected_suffix.append(node_id)
|
|
prev_node = node_id
|
|
|
|
sql = """
|
|
SELECT chunk_id, numerator, denominator FROM chunk_linearized
|
|
WHERE room_id = ?
|
|
"""
|
|
txn.execute(sql, (room_id,))
|
|
|
|
ordered = sorted([(Fraction(n, d), r) for r, n, d in txn])
|
|
ordered = [c for _, c in ordered]
|
|
|
|
expected = expected_prefix + list(reversed(expected_suffix))
|
|
|
|
self.assertEqual(expected, ordered)
|
|
|
|
yield self.store.runInteraction("test", test_txn)
|
|
|
|
@defer.inlineCallbacks
|
|
def test_get_edges_to(self):
|
|
room_id = "foo_room4"
|
|
|
|
def test_txn(txn):
|
|
table = ChunkDBOrderedListStore(
|
|
txn, room_id, self.clock,
|
|
self.store.database_engine,
|
|
5, 100,
|
|
)
|
|
|
|
table.add_node("A")
|
|
table._insert_after("B", "A")
|
|
table._add_edge_to_graph("A", "B")
|
|
table._insert_before("C", "A")
|
|
table._add_edge_to_graph("C", "A")
|
|
|
|
nodes = table.get_nodes_with_edges_from("A")
|
|
self.assertEqual([n for _, n in nodes], ["B"])
|
|
|
|
nodes = table.get_nodes_with_edges_to("A")
|
|
self.assertEqual([n for _, n in nodes], ["C"])
|
|
|
|
yield self.store.runInteraction("test", test_txn)
|
|
|
|
@defer.inlineCallbacks
|
|
def test_get_next_and_prev(self):
|
|
room_id = "foo_room5"
|
|
|
|
def test_txn(txn):
|
|
table = ChunkDBOrderedListStore(
|
|
txn, room_id, self.clock,
|
|
self.store.database_engine,
|
|
5, 100,
|
|
)
|
|
|
|
table.add_node("A")
|
|
table._insert_after("B", "A")
|
|
table._insert_before("C", "A")
|
|
|
|
self.assertEqual(table.get_next("A"), "B")
|
|
self.assertEqual(table.get_prev("A"), "C")
|
|
|
|
yield self.store.runInteraction("test", test_txn)
|
|
|
|
def test_find_farey_terms(self):
|
|
def _test(min_frac, max_denom):
|
|
""""Calls `find_farey_terms` with given values and checks they
|
|
are neighbours in the Farey Sequence.
|
|
"""
|
|
|
|
a, b, c, d = find_farey_terms(min_frac, max_denom)
|
|
|
|
p = Fraction(a, b)
|
|
q = Fraction(c, d)
|
|
|
|
assert min_frac < p < q
|
|
|
|
for x, y in _pairwise(_farey_generator(max_denom)):
|
|
if min_frac < x < y:
|
|
self.assertEqual(x, p)
|
|
self.assertEqual(y, q)
|
|
break
|
|
|
|
_test(Fraction(5, 3), 12)
|
|
_test(Fraction(1, 3), 12)
|
|
_test(Fraction(1, 2), 9)
|
|
_test(Fraction(1, 2), 10)
|
|
_test(Fraction(1, 2), 15)
|
|
|
|
def test_get_fraction_in_range(self):
|
|
def _test(x, y):
|
|
assert x < get_fraction_in_range(x, y) < y
|
|
|
|
_test(Fraction(1, 2), Fraction(2, 3))
|
|
_test(Fraction(1, 2), Fraction(3, 2))
|
|
_test(Fraction(5, 203), Fraction(6, 204))
|
|
|
|
|
|
def _farey_generator(n):
|
|
"""Generates Farey sequence of order `n`.
|
|
|
|
Note that this doesn't terminate.
|
|
|
|
Taken from https://en.wikipedia.org/wiki/Farey_sequence#Next_term
|
|
"""
|
|
|
|
a, b, c, d = 0, 1, 1, n
|
|
|
|
yield Fraction(a, b)
|
|
|
|
while True:
|
|
k = int((n + b) / d)
|
|
a, b, c, d = c, d, (k * c - a), (k * d - b)
|
|
yield Fraction(a, b)
|
|
|
|
|
|
def _pairwise(iterable):
|
|
"s -> (s0,s1), (s1,s2), (s2, s3), ..."
|
|
a, b = itertools.tee(iterable)
|
|
next(b, None)
|
|
return itertools.izip(a, b)
|