Add type hints to response cache. (#8507)

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Patrick Cloke 2020-10-09 11:35:11 -04:00 committed by GitHub
parent 66ac4b1e34
commit 1781bbe319
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9 changed files with 48 additions and 34 deletions

1
changelog.d/8507.misc Normal file
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@ -0,0 +1 @@
Add type hints to various parts of the code base.

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@ -65,6 +65,7 @@ files =
synapse/types.py,
synapse/util/async_helpers.py,
synapse/util/caches/descriptors.py,
synapse/util/caches/response_cache.py,
synapse/util/caches/stream_change_cache.py,
synapse/util/metrics.py,
tests/replication,

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@ -14,7 +14,7 @@
# limitations under the License.
import logging
import urllib
from typing import TYPE_CHECKING, Optional
from typing import TYPE_CHECKING, Optional, Tuple
from prometheus_client import Counter
@ -93,7 +93,7 @@ class ApplicationServiceApi(SimpleHttpClient):
self.protocol_meta_cache = ResponseCache(
hs, "as_protocol_meta", timeout_ms=HOUR_IN_MS
)
) # type: ResponseCache[Tuple[str, str]]
async def query_user(self, service, user_id):
if service.url is None:

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@ -116,7 +116,7 @@ class FederationServer(FederationBase):
# We cache results for transaction with the same ID
self._transaction_resp_cache = ResponseCache(
hs, "fed_txn_handler", timeout_ms=30000
)
) # type: ResponseCache[Tuple[str, str]]
self.transaction_actions = TransactionActions(self.store)
@ -124,10 +124,12 @@ class FederationServer(FederationBase):
# We cache responses to state queries, as they take a while and often
# come in waves.
self._state_resp_cache = ResponseCache(hs, "state_resp", timeout_ms=30000)
self._state_resp_cache = ResponseCache(
hs, "state_resp", timeout_ms=30000
) # type: ResponseCache[Tuple[str, str]]
self._state_ids_resp_cache = ResponseCache(
hs, "state_ids_resp", timeout_ms=30000
)
) # type: ResponseCache[Tuple[str, str]]
self._federation_metrics_domains = (
hs.get_config().federation.federation_metrics_domains

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@ -14,7 +14,7 @@
# limitations under the License.
import logging
from typing import TYPE_CHECKING
from typing import TYPE_CHECKING, Optional, Tuple
from twisted.internet import defer
@ -47,12 +47,14 @@ class InitialSyncHandler(BaseHandler):
self.state = hs.get_state_handler()
self.clock = hs.get_clock()
self.validator = EventValidator()
self.snapshot_cache = ResponseCache(hs, "initial_sync_cache")
self.snapshot_cache = ResponseCache(
hs, "initial_sync_cache"
) # type: ResponseCache[Tuple[str, Optional[StreamToken], Optional[StreamToken], str, Optional[int], bool, bool]]
self._event_serializer = hs.get_event_client_serializer()
self.storage = hs.get_storage()
self.state_store = self.storage.state
def snapshot_all_rooms(
async def snapshot_all_rooms(
self,
user_id: str,
pagin_config: PaginationConfig,
@ -84,7 +86,7 @@ class InitialSyncHandler(BaseHandler):
include_archived,
)
return self.snapshot_cache.wrap(
return await self.snapshot_cache.wrap(
key,
self._snapshot_all_rooms,
user_id,

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@ -120,7 +120,7 @@ class RoomCreationHandler(BaseHandler):
# subsequent requests
self._upgrade_response_cache = ResponseCache(
hs, "room_upgrade", timeout_ms=FIVE_MINUTES_IN_MS
)
) # type: ResponseCache[Tuple[str, str]]
self._server_notices_mxid = hs.config.server_notices_mxid
self.third_party_event_rules = hs.get_third_party_event_rules()

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@ -243,7 +243,9 @@ class SyncHandler:
self.presence_handler = hs.get_presence_handler()
self.event_sources = hs.get_event_sources()
self.clock = hs.get_clock()
self.response_cache = ResponseCache(hs, "sync")
self.response_cache = ResponseCache(
hs, "sync"
) # type: ResponseCache[Tuple[Any, ...]]
self.state = hs.get_state_handler()
self.auth = hs.get_auth()
self.storage = hs.get_storage()

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@ -92,7 +92,7 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta):
if self.CACHE:
self.response_cache = ResponseCache(
hs, "repl." + self.NAME, timeout_ms=30 * 60 * 1000
)
) # type: ResponseCache[str]
# We reserve `instance_name` as a parameter to sending requests, so we
# assert here that sub classes don't try and use the name.

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@ -13,6 +13,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
from typing import TYPE_CHECKING, Any, Callable, Dict, Generic, Optional, TypeVar
from twisted.internet import defer
@ -20,10 +21,15 @@ from synapse.logging.context import make_deferred_yieldable, run_in_background
from synapse.util.async_helpers import ObservableDeferred
from synapse.util.caches import register_cache
if TYPE_CHECKING:
from synapse.app.homeserver import HomeServer
logger = logging.getLogger(__name__)
T = TypeVar("T")
class ResponseCache:
class ResponseCache(Generic[T]):
"""
This caches a deferred response. Until the deferred completes it will be
returned from the cache. This means that if the client retries the request
@ -31,8 +37,9 @@ class ResponseCache:
used rather than trying to compute a new response.
"""
def __init__(self, hs, name, timeout_ms=0):
self.pending_result_cache = {} # Requests that haven't finished yet.
def __init__(self, hs: "HomeServer", name: str, timeout_ms: float = 0):
# Requests that haven't finished yet.
self.pending_result_cache = {} # type: Dict[T, ObservableDeferred]
self.clock = hs.get_clock()
self.timeout_sec = timeout_ms / 1000.0
@ -40,13 +47,13 @@ class ResponseCache:
self._name = name
self._metrics = register_cache("response_cache", name, self, resizable=False)
def size(self):
def size(self) -> int:
return len(self.pending_result_cache)
def __len__(self):
def __len__(self) -> int:
return self.size()
def get(self, key):
def get(self, key: T) -> Optional[defer.Deferred]:
"""Look up the given key.
Can return either a new Deferred (which also doesn't follow the synapse
@ -58,12 +65,11 @@ class ResponseCache:
from an absent cache entry.
Args:
key (hashable):
key: key to get/set in the cache
Returns:
twisted.internet.defer.Deferred|None|E: None if there is no entry
for this key; otherwise either a deferred result or the result
itself.
None if there is no entry for this key; otherwise a deferred which
resolves to the result.
"""
result = self.pending_result_cache.get(key)
if result is not None:
@ -73,7 +79,7 @@ class ResponseCache:
self._metrics.inc_misses()
return None
def set(self, key, deferred):
def set(self, key: T, deferred: defer.Deferred) -> defer.Deferred:
"""Set the entry for the given key to the given deferred.
*deferred* should run its callbacks in the sentinel logcontext (ie,
@ -85,12 +91,11 @@ class ResponseCache:
result. You will probably want to make_deferred_yieldable the result.
Args:
key (hashable):
deferred (twisted.internet.defer.Deferred[T):
key: key to get/set in the cache
deferred: The deferred which resolves to the result.
Returns:
twisted.internet.defer.Deferred[T]|T: a new deferred, or the actual
result.
A new deferred which resolves to the actual result.
"""
result = ObservableDeferred(deferred, consumeErrors=True)
self.pending_result_cache[key] = result
@ -107,7 +112,9 @@ class ResponseCache:
result.addBoth(remove)
return result.observe()
def wrap(self, key, callback, *args, **kwargs):
def wrap(
self, key: T, callback: "Callable[..., Any]", *args: Any, **kwargs: Any
) -> defer.Deferred:
"""Wrap together a *get* and *set* call, taking care of logcontexts
First looks up the key in the cache, and if it is present makes it
@ -118,21 +125,20 @@ class ResponseCache:
Example usage:
@defer.inlineCallbacks
def handle_request(request):
async def handle_request(request):
# etc
return result
result = yield response_cache.wrap(
result = await response_cache.wrap(
key,
handle_request,
request,
)
Args:
key (hashable): key to get/set in the cache
key: key to get/set in the cache
callback (callable): function to call if the key is not found in
callback: function to call if the key is not found in
the cache
*args: positional parameters to pass to the callback, if it is used
@ -140,7 +146,7 @@ class ResponseCache:
**kwargs: named parameters to pass to the callback, if it is used
Returns:
twisted.internet.defer.Deferred: yieldable result
Deferred which resolves to the result
"""
result = self.get(key)
if not result: