Simplify the way the `HomeServer` object caches its internal attributes. (#8565)

Changes `@cache_in_self` to use underscore-prefixed attributes.

11 files changed, 39 insertions, 35 deletions

diff --git a/changelog.d/8565.misc b/changelog.d/8565.misc
new file mode 100644
index 0000000000..7bef422618
--- /dev/null
+++ b/changelog.d/8565.misc
@@ -0,0 +1 @@
+Simplify the way the `HomeServer` object caches its internal attributes.
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py
index bc3e9607ca..9b3c6b4551 100644
--- a/synapse/handlers/identity.py
+++ b/synapse/handlers/identity.py
@@ -354,7 +354,8 @@ class IdentityHandler(BaseHandler):
             raise SynapseError(500, "An error was encountered when sending the email")
 
         token_expires = (
-            self.hs.clock.time_msec() + self.hs.config.email_validation_token_lifetime
+            self.hs.get_clock().time_msec()
+            + self.hs.config.email_validation_token_lifetime
         )
 
         await self.store.start_or_continue_validation_session(
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index a54e1011f7..eebee44a44 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -115,7 +115,7 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
                 # comments for request_token_inhibit_3pid_errors.
                 # Also wait for some random amount of time between 100ms and 1s to make it
                 # look like we did something.
-                await self.hs.clock.sleep(random.randint(1, 10) / 10)
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "Email not found", Codes.THREEPID_NOT_FOUND)
@@ -387,7 +387,7 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
                 # comments for request_token_inhibit_3pid_errors.
                 # Also wait for some random amount of time between 100ms and 1s to make it
                 # look like we did something.
-                await self.hs.clock.sleep(random.randint(1, 10) / 10)
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
@@ -466,7 +466,7 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet):
                 # comments for request_token_inhibit_3pid_errors.
                 # Also wait for some random amount of time between 100ms and 1s to make it
                 # look like we did something.
-                await self.hs.clock.sleep(random.randint(1, 10) / 10)
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "MSISDN is already in use", Codes.THREEPID_IN_USE)
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index ea68114026..a89ae6ddf9 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -135,7 +135,7 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
                 # comments for request_token_inhibit_3pid_errors.
                 # Also wait for some random amount of time between 100ms and 1s to make it
                 # look like we did something.
-                await self.hs.clock.sleep(random.randint(1, 10) / 10)
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
@@ -214,7 +214,7 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet):
                 # comments for request_token_inhibit_3pid_errors.
                 # Also wait for some random amount of time between 100ms and 1s to make it
                 # look like we did something.
-                await self.hs.clock.sleep(random.randint(1, 10) / 10)
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
                 return 200, {"sid": random_string(16)}
 
             raise SynapseError(
diff --git a/synapse/rest/key/v2/local_key_resource.py b/synapse/rest/key/v2/local_key_resource.py
index c16280f668..d8e8e48c1c 100644
--- a/synapse/rest/key/v2/local_key_resource.py
+++ b/synapse/rest/key/v2/local_key_resource.py
@@ -66,7 +66,7 @@ class LocalKey(Resource):
 
     def __init__(self, hs):
         self.config = hs.config
-        self.clock = hs.clock
+        self.clock = hs.get_clock()
         self.update_response_body(self.clock.time_msec())
         Resource.__init__(self)
 
diff --git a/synapse/server.py b/synapse/server.py
index c82d8f9fad..b017e3489f 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -147,7 +147,8 @@ def cache_in_self(builder: T) -> T:
             "@cache_in_self can only be used on functions starting with `get_`"
         )
 
-    depname = builder.__name__[len("get_") :]
+    # get_attr -> _attr
+    depname = builder.__name__[len("get") :]
 
     building = [False]
 
@@ -235,15 +236,6 @@ class HomeServer(metaclass=abc.ABCMeta):
         self._instance_id = random_string(5)
         self._instance_name = config.worker_name or "master"
 
-        self.clock = Clock(reactor)
-        self.distributor = Distributor()
-
-        self.registration_ratelimiter = Ratelimiter(
-            clock=self.clock,
-            rate_hz=config.rc_registration.per_second,
-            burst_count=config.rc_registration.burst_count,
-        )
-
         self.version_string = version_string
 
         self.datastores = None  # type: Optional[Databases]
@@ -301,8 +293,9 @@ class HomeServer(metaclass=abc.ABCMeta):
     def is_mine_id(self, string: str) -> bool:
         return string.split(":", 1)[1] == self.hostname
 
+    @cache_in_self
     def get_clock(self) -> Clock:
-        return self.clock
+        return Clock(self._reactor)
 
     def get_datastore(self) -> DataStore:
         if not self.datastores:
@@ -319,11 +312,17 @@ class HomeServer(metaclass=abc.ABCMeta):
     def get_config(self) -> HomeServerConfig:
         return self.config
 
+    @cache_in_self
     def get_distributor(self) -> Distributor:
-        return self.distributor
+        return Distributor()
 
+    @cache_in_self
     def get_registration_ratelimiter(self) -> Ratelimiter:
-        return self.registration_ratelimiter
+        return Ratelimiter(
+            clock=self.get_clock(),
+            rate_hz=self.config.rc_registration.per_second,
+            burst_count=self.config.rc_registration.burst_count,
+        )
 
     @cache_in_self
     def get_federation_client(self) -> FederationClient:
@@ -687,7 +686,7 @@ class HomeServer(metaclass=abc.ABCMeta):
 
     @cache_in_self
     def get_federation_ratelimiter(self) -> FederationRateLimiter:
-        return FederationRateLimiter(self.clock, config=self.config.rc_federation)
+        return FederationRateLimiter(self.get_clock(), config=self.config.rc_federation)
 
     @cache_in_self
     def get_module_api(self) -> ModuleApi:
diff --git a/tests/handlers/test_auth.py b/tests/handlers/test_auth.py
index b5055e018c..e24ce81284 100644
--- a/tests/handlers/test_auth.py
+++ b/tests/handlers/test_auth.py
@@ -52,7 +52,7 @@ class AuthTestCase(unittest.TestCase):
             self.fail("some_user was not in %s" % macaroon.inspect())
 
     def test_macaroon_caveats(self):
-        self.hs.clock.now = 5000
+        self.hs.get_clock().now = 5000
 
         token = self.macaroon_generator.generate_access_token("a_user")
         macaroon = pymacaroons.Macaroon.deserialize(token)
@@ -78,7 +78,7 @@ class AuthTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_short_term_login_token_gives_user_id(self):
-        self.hs.clock.now = 1000
+        self.hs.get_clock().now = 1000
 
         token = self.macaroon_generator.generate_short_term_login_token("a_user", 5000)
         user_id = yield defer.ensureDeferred(
@@ -87,7 +87,7 @@ class AuthTestCase(unittest.TestCase):
         self.assertEqual("a_user", user_id)
 
         # when we advance the clock, the token should be rejected
-        self.hs.clock.now = 6000
+        self.hs.get_clock().now = 6000
         with self.assertRaises(synapse.api.errors.AuthError):
             yield defer.ensureDeferred(
                 self.auth_handler.validate_short_term_login_token_and_get_user_id(token)
diff --git a/tests/replication/_base.py b/tests/replication/_base.py
index 516db4c30a..295c5d58a6 100644
--- a/tests/replication/_base.py
+++ b/tests/replication/_base.py
@@ -78,7 +78,7 @@ class BaseStreamTestCase(unittest.HomeserverTestCase):
         self.worker_hs.get_datastore().db_pool = hs.get_datastore().db_pool
 
         self.test_handler = self._build_replication_data_handler()
-        self.worker_hs.replication_data_handler = self.test_handler
+        self.worker_hs._replication_data_handler = self.test_handler
 
         repl_handler = ReplicationCommandHandler(self.worker_hs)
         self.client = ClientReplicationStreamProtocol(
diff --git a/tests/rest/client/v1/test_presence.py b/tests/rest/client/v1/test_presence.py
index b84f86d28c..5d5c24d01c 100644
--- a/tests/rest/client/v1/test_presence.py
+++ b/tests/rest/client/v1/test_presence.py
@@ -33,13 +33,16 @@ class PresenceTestCase(unittest.HomeserverTestCase):
 
     def make_homeserver(self, reactor, clock):
 
+        presence_handler = Mock()
+        presence_handler.set_state.return_value = defer.succeed(None)
+
         hs = self.setup_test_homeserver(
-            "red", http_client=None, federation_client=Mock()
+            "red",
+            http_client=None,
+            federation_client=Mock(),
+            presence_handler=presence_handler,
         )
 
-        hs.presence_handler = Mock()
-        hs.presence_handler.set_state.return_value = defer.succeed(None)
-
         return hs
 
     def test_put_presence(self):
@@ -55,7 +58,7 @@ class PresenceTestCase(unittest.HomeserverTestCase):
         )
 
         self.assertEqual(channel.code, 200)
-        self.assertEqual(self.hs.presence_handler.set_state.call_count, 1)
+        self.assertEqual(self.hs.get_presence_handler().set_state.call_count, 1)
 
     def test_put_presence_disabled(self):
         """
@@ -70,4 +73,4 @@ class PresenceTestCase(unittest.HomeserverTestCase):
         )
 
         self.assertEqual(channel.code, 200)
-        self.assertEqual(self.hs.presence_handler.set_state.call_count, 0)
+        self.assertEqual(self.hs.get_presence_handler().set_state.call_count, 0)
diff --git a/tests/rest/client/v2_alpha/test_register.py b/tests/rest/client/v2_alpha/test_register.py
index 699a40c3df..8f0c2430e8 100644
--- a/tests/rest/client/v2_alpha/test_register.py
+++ b/tests/rest/client/v2_alpha/test_register.py
@@ -569,7 +569,7 @@ class AccountValidityRenewalByEmailTestCase(unittest.HomeserverTestCase):
         tok = self.login("kermit", "monkey")
         # We need to manually add an email address otherwise the handler will do
         # nothing.
-        now = self.hs.clock.time_msec()
+        now = self.hs.get_clock().time_msec()
         self.get_success(
             self.store.user_add_threepid(
                 user_id=user_id,
@@ -587,7 +587,7 @@ class AccountValidityRenewalByEmailTestCase(unittest.HomeserverTestCase):
 
         # We need to manually add an email address otherwise the handler will do
         # nothing.
-        now = self.hs.clock.time_msec()
+        now = self.hs.get_clock().time_msec()
         self.get_success(
             self.store.user_add_threepid(
                 user_id=user_id,
@@ -646,7 +646,7 @@ class AccountValidityBackgroundJobTestCase(unittest.HomeserverTestCase):
 
         self.hs.config.account_validity.startup_job_max_delta = self.max_delta
 
-        now_ms = self.hs.clock.time_msec()
+        now_ms = self.hs.get_clock().time_msec()
         self.get_success(self.store._set_expiration_date_when_missing())
 
         res = self.get_success(self.store.get_expiration_ts_for_user(user_id))
diff --git a/tests/utils.py b/tests/utils.py
index acec74e9e9..c8d3ffbaba 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -271,7 +271,7 @@ def setup_test_homeserver(
 
     # Install @cache_in_self attributes
     for key, val in kwargs.items():
-        setattr(hs, key, val)
+        setattr(hs, "_" + key, val)
 
     # Mock TLS
     hs.tls_server_context_factory = Mock()