synapse/tests/util/test_stream_change_cache.py
Patrick Cloke da77720752
Check the stream position before checking if the cache is empty. (#14639)
An empty cache does not mean the entity has no changed, if
it is earlier than the earliest known stream position return that
the entity *has* changed since the cache cannot accurately
answer that query.
2022-12-08 11:35:49 -05:00

242 lines
9.7 KiB
Python

from synapse.util.caches.stream_change_cache import StreamChangeCache
from tests import unittest
class StreamChangeCacheTests(unittest.HomeserverTestCase):
"""
Tests for StreamChangeCache.
"""
def test_prefilled_cache(self) -> None:
"""
Providing a prefilled cache to StreamChangeCache will result in a cache
with the prefilled-cache entered in.
"""
cache = StreamChangeCache("#test", 1, prefilled_cache={"user@foo.com": 2})
self.assertTrue(cache.has_entity_changed("user@foo.com", 1))
def test_has_entity_changed(self) -> None:
"""
StreamChangeCache.entity_has_changed will mark entities as changed, and
has_entity_changed will observe the changed entities.
"""
cache = StreamChangeCache("#test", 3)
cache.entity_has_changed("user@foo.com", 6)
cache.entity_has_changed("bar@baz.net", 7)
# also test multiple things changing on the same stream ID
cache.entity_has_changed("user2@foo.com", 8)
cache.entity_has_changed("bar2@baz.net", 8)
# If it's been changed after that stream position, return True
self.assertTrue(cache.has_entity_changed("user@foo.com", 4))
self.assertTrue(cache.has_entity_changed("bar@baz.net", 4))
self.assertTrue(cache.has_entity_changed("bar2@baz.net", 4))
self.assertTrue(cache.has_entity_changed("user2@foo.com", 4))
# If it's been changed at that stream position, return False
self.assertFalse(cache.has_entity_changed("user@foo.com", 6))
self.assertFalse(cache.has_entity_changed("user2@foo.com", 8))
# If there's no changes after that stream position, return False
self.assertFalse(cache.has_entity_changed("user@foo.com", 7))
self.assertFalse(cache.has_entity_changed("user2@foo.com", 9))
# If the entity does not exist, return False.
self.assertFalse(cache.has_entity_changed("not@here.website", 9))
# If we request before the stream cache's earliest known position,
# return True, whether it's a known entity or not.
self.assertTrue(cache.has_entity_changed("user@foo.com", 0))
self.assertTrue(cache.has_entity_changed("not@here.website", 0))
self.assertTrue(cache.has_entity_changed("user@foo.com", 3))
self.assertTrue(cache.has_entity_changed("not@here.website", 3))
def test_entity_has_changed_pops_off_start(self) -> None:
"""
StreamChangeCache.entity_has_changed will respect the max size and
purge the oldest items upon reaching that max size.
"""
cache = StreamChangeCache("#test", 1, max_size=2)
cache.entity_has_changed("user@foo.com", 2)
cache.entity_has_changed("bar@baz.net", 3)
cache.entity_has_changed("user@elsewhere.org", 4)
# The cache is at the max size, 2
self.assertEqual(len(cache._cache), 2)
# The cache's earliest known position is 2.
self.assertEqual(cache._earliest_known_stream_pos, 2)
# The oldest item has been popped off
self.assertTrue("user@foo.com" not in cache._entity_to_key)
self.assertEqual(
cache.get_all_entities_changed(3).entities, ["user@elsewhere.org"]
)
self.assertFalse(cache.get_all_entities_changed(2).hit)
# If we update an existing entity, it keeps the two existing entities
cache.entity_has_changed("bar@baz.net", 5)
self.assertEqual(
{"bar@baz.net", "user@elsewhere.org"}, set(cache._entity_to_key)
)
self.assertEqual(
cache.get_all_entities_changed(3).entities,
["user@elsewhere.org", "bar@baz.net"],
)
self.assertFalse(cache.get_all_entities_changed(2).hit)
def test_get_all_entities_changed(self) -> None:
"""
StreamChangeCache.get_all_entities_changed will return all changed
entities since the given position. If the position is before the start
of the known stream, it returns None instead.
"""
cache = StreamChangeCache("#test", 1)
cache.entity_has_changed("user@foo.com", 2)
cache.entity_has_changed("bar@baz.net", 3)
cache.entity_has_changed("anotheruser@foo.com", 3)
cache.entity_has_changed("user@elsewhere.org", 4)
r = cache.get_all_entities_changed(2)
# Results are ordered so either of these are valid.
ok1 = ["bar@baz.net", "anotheruser@foo.com", "user@elsewhere.org"]
ok2 = ["anotheruser@foo.com", "bar@baz.net", "user@elsewhere.org"]
self.assertTrue(r.entities == ok1 or r.entities == ok2)
self.assertEqual(
cache.get_all_entities_changed(3).entities, ["user@elsewhere.org"]
)
self.assertFalse(cache.get_all_entities_changed(1).hit)
# ... later, things gest more updates
cache.entity_has_changed("user@foo.com", 5)
cache.entity_has_changed("bar@baz.net", 5)
cache.entity_has_changed("anotheruser@foo.com", 6)
ok1 = [
"user@elsewhere.org",
"user@foo.com",
"bar@baz.net",
"anotheruser@foo.com",
]
ok2 = [
"user@elsewhere.org",
"bar@baz.net",
"user@foo.com",
"anotheruser@foo.com",
]
r = cache.get_all_entities_changed(3)
self.assertTrue(r.entities == ok1 or r.entities == ok2)
def test_has_any_entity_changed(self) -> None:
"""
StreamChangeCache.has_any_entity_changed will return True if any
entities have been changed since the provided stream position, and
False if they have not. If the cache has entries and the provided
stream position is before it, it will return True, otherwise False if
the cache has no entries.
"""
cache = StreamChangeCache("#test", 1)
# With no entities, it returns True for the past, present, and False for
# the future.
self.assertTrue(cache.has_any_entity_changed(0))
self.assertTrue(cache.has_any_entity_changed(1))
self.assertFalse(cache.has_any_entity_changed(2))
# We add an entity
cache.entity_has_changed("user@foo.com", 2)
# With an entity, it returns True for the past, the stream start
# position, and False for the stream position the entity was changed
# on and ones after it.
self.assertTrue(cache.has_any_entity_changed(0))
self.assertTrue(cache.has_any_entity_changed(1))
self.assertFalse(cache.has_any_entity_changed(2))
self.assertFalse(cache.has_any_entity_changed(3))
def test_get_entities_changed(self) -> None:
"""
StreamChangeCache.get_entities_changed will return the entities in the
given list that have changed since the provided stream ID. If the
stream position is earlier than the earliest known position, it will
return all of the entities queried for.
"""
cache = StreamChangeCache("#test", 1)
cache.entity_has_changed("user@foo.com", 2)
cache.entity_has_changed("bar@baz.net", 3)
cache.entity_has_changed("user@elsewhere.org", 4)
# Query all the entries, but mid-way through the stream. We should only
# get the ones after that point.
self.assertEqual(
cache.get_entities_changed(
["user@foo.com", "bar@baz.net", "user@elsewhere.org"], stream_pos=2
),
{"bar@baz.net", "user@elsewhere.org"},
)
# Query all the entries mid-way through the stream, but include one
# that doesn't exist in it. We shouldn't get back the one that doesn't
# exist.
self.assertEqual(
cache.get_entities_changed(
[
"user@foo.com",
"bar@baz.net",
"user@elsewhere.org",
"not@here.website",
],
stream_pos=2,
),
{"bar@baz.net", "user@elsewhere.org"},
)
# Query all the entries, but before the first known point. We will get
# all the entries we queried for, including ones that don't exist.
self.assertEqual(
cache.get_entities_changed(
[
"user@foo.com",
"bar@baz.net",
"user@elsewhere.org",
"not@here.website",
],
stream_pos=0,
),
{"user@foo.com", "bar@baz.net", "user@elsewhere.org", "not@here.website"},
)
# Query a subset of the entries mid-way through the stream. We should
# only get back the subset.
self.assertEqual(
cache.get_entities_changed(["bar@baz.net"], stream_pos=2),
{"bar@baz.net"},
)
def test_max_pos(self) -> None:
"""
StreamChangeCache.get_max_pos_of_last_change will return the most
recent point where the entity could have changed. If the entity is not
known, the stream start is provided instead.
"""
cache = StreamChangeCache("#test", 1)
cache.entity_has_changed("user@foo.com", 2)
cache.entity_has_changed("bar@baz.net", 3)
cache.entity_has_changed("user@elsewhere.org", 4)
# Known entities will return the point where they were changed.
self.assertEqual(cache.get_max_pos_of_last_change("user@foo.com"), 2)
self.assertEqual(cache.get_max_pos_of_last_change("bar@baz.net"), 3)
self.assertEqual(cache.get_max_pos_of_last_change("user@elsewhere.org"), 4)
# Unknown entities will return the stream start position.
self.assertEqual(cache.get_max_pos_of_last_change("not@here.website"), 1)