Merge pull request #1606 from matrix-org/andy/megolm_cache

Remove megolm decrypt cache build flag
matrix-org · Oct 17, 2022 · aed6ebb · aed6ebb
2 parents 1689413 + 2a08b43
commit aed6ebb
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Showing 5 changed files with 14 additions and 57 deletions.
diff --git a/MatrixSDK/Crypto/MXOlmDevice.m b/MatrixSDK/Crypto/MXOlmDevice.m
@@ -429,13 +429,10 @@ - (void)upgradeSafetyForSession:(MXOlmInboundGroupSession *)session
     [self.store performSessionOperationWithGroupSessionWithId:session.session.sessionIdentifier senderKey:session.senderKey block:^(MXOlmInboundGroupSession *inboundGroupSession) {
         inboundGroupSession.untrusted = NO;
     }];
-    if (MXSDKOptions.sharedInstance.enableGroupSessionCache)
+    @synchronized (self.inboundGroupSessionCache)
     {
-        @synchronized (self.inboundGroupSessionCache)
-        {
-            session.untrusted = NO;
-            [self.inboundGroupSessionCache put:session.session.sessionIdentifier object:session];
-        }
+        session.untrusted = NO;
+        [self.inboundGroupSessionCache put:session.session.sessionIdentifier object:session];
     }
 }
 
@@ -572,34 +569,16 @@ - (MXDecryptionResult *)decryptGroupMessage:(NSString *)body
 
 - (void)performGroupSessionOperationWithSessionId:(NSString*)sessionId senderKey:(NSString*)senderKey block:(void (^)(MXOlmInboundGroupSession *inboundGroupSession))block
 {
-    // Based on a feature flag megolm decryption will either fetch a group session from the store on every decryption,
-    // or (if the flag is enabled) it will use LRU cache to avoid refetching unchanged sessions.
-    //
-    // Additionally the duration of each variant is tracked in analytics (if configured and enabled by the user)
-    // to allow performance comparison
-    //
-    // LRU cache variant will eventually become the default implementation if proved stable.
-
-    BOOL enableCache = MXSDKOptions.sharedInstance.enableGroupSessionCache;
-    NSString *operation = enableCache ? @"megolm.decrypt.cache" : @"megolm.decrypt.store";
-    StopDurationTracking stopTracking = [MXSDKOptions.sharedInstance.analyticsDelegate startDurationTrackingForName:@"MXOlmDevice" operation:operation];
-
-    if (enableCache)
+    StopDurationTracking stopTracking = [MXSDKOptions.sharedInstance.analyticsDelegate startDurationTrackingForName:@"MXOlmDevice" operation:@"megolm.decrypt.cache"];
+    @synchronized (self.inboundGroupSessionCache)
     {
-        @synchronized (self.inboundGroupSessionCache)
+        MXOlmInboundGroupSession *session = (MXOlmInboundGroupSession *)[self.inboundGroupSessionCache get:sessionId];
+        if (!session)
         {
-            MXOlmInboundGroupSession *session = (MXOlmInboundGroupSession *)[self.inboundGroupSessionCache get:sessionId];
-            if (!session)
-            {
-                session = [store inboundGroupSessionWithId:sessionId andSenderKey:senderKey];
-                [self.inboundGroupSessionCache put:sessionId object:session];
-            }
-            block(session);
+            session = [store inboundGroupSessionWithId:sessionId andSenderKey:senderKey];
+            [self.inboundGroupSessionCache put:sessionId object:session];
         }
-    }
-    else
-    {
-        [store performSessionOperationWithGroupSessionWithId:sessionId senderKey:senderKey block:block];
+        block(session);
     }
     if (stopTracking)
     {
@@ -711,14 +690,11 @@ - (NSDictionary*)getInboundGroupSessionKey:(NSString*)roomId senderKey:(NSString
 - (void)storeInboundGroupSessions:(NSArray <MXOlmInboundGroupSession *>*)sessions
 {
     [store storeInboundGroupSessions:sessions];
-    if (MXSDKOptions.sharedInstance.enableGroupSessionCache)
+    @synchronized (self.inboundGroupSessionCache)
     {
-        @synchronized (self.inboundGroupSessionCache)
+        for (MXOlmInboundGroupSession *session in sessions)
         {
-            for (MXOlmInboundGroupSession *session in sessions)
-            {
-                [self.inboundGroupSessionCache put:session.session.sessionIdentifier object:session];
-            }
+            [self.inboundGroupSessionCache put:session.session.sessionIdentifier object:session];
         }
     }
 }

diff --git a/MatrixSDK/MXSDKOptions.h b/MatrixSDK/MXSDKOptions.h
@@ -216,14 +216,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 #endif
 
-/**
- Enable performance optimization where inbound group sessions are cached between decryption of events
- rather than fetched from the store every time.
- 
- @remark YES by default
- */
-@property (nonatomic) BOOL enableGroupSessionCache;
-
 /**
  Enable symmetric room key backups
  

diff --git a/MatrixSDK/MXSDKOptions.m b/MatrixSDK/MXSDKOptions.m
@@ -59,7 +59,6 @@ - (instancetype)init
         _enableCryptoV2 = NO;
         #endif
 
-        _enableGroupSessionCache = YES;
         _enableSymmetricBackup = NO;
         _enableNewClientInformationFeature = NO;
     }

diff --git a/MatrixSDK/MXSession.m b/MatrixSDK/MXSession.m
@@ -1412,7 +1412,6 @@ - (void)serverSyncWithServerTimeout:(NSUInteger)serverTimeout
     dispatch_group_t initialSyncDispatchGroup = dispatch_group_create();
 
     __block MXTaskProfile *syncTaskProfile;
-    __block StopDurationTracking stopDurationTracking;
     __block MXSyncResponse *syncResponse;
     __block BOOL useLiveResponse = YES;
 
@@ -1444,13 +1443,6 @@ - (void)serverSyncWithServerTimeout:(NSUInteger)serverTimeout
             BOOL isInitialSync = !self.isEventStreamInitialised;
             MXTaskProfileName taskName = isInitialSync ? MXTaskProfileNameStartupInitialSync : MXTaskProfileNameStartupIncrementalSync;
             syncTaskProfile = [MXSDKOptions.sharedInstance.profiler startMeasuringTaskWithName:taskName];
-            if (isInitialSync) {
-                // Temporarily tracking performance both by `MXSDKOptions.sharedInstance.profiler` (manually measuring time)
-                // and `MXSDKOptions.sharedInstance.analyticsDelegate` (delegating to performance monitoring tool).
-                // This ambiguity will be resolved in the future
-                NSString *operation = MXSDKOptions.sharedInstance.enableGroupSessionCache ? @"initialSync.enableGroupSessionCache" : @"initialSync.diableGroupSessionCache";
-                stopDurationTracking = [MXSDKOptions.sharedInstance.analyticsDelegate startDurationTrackingForName:@"MXSession" operation:operation];
-            }
         }
 
         NSString * streamToken = self.store.eventStreamToken;
@@ -1493,9 +1485,6 @@ - (void)serverSyncWithServerTimeout:(NSUInteger)serverTimeout
             syncTaskProfile.units = syncResponse.rooms.join.count;
 
             [MXSDKOptions.sharedInstance.profiler stopMeasuringTaskWithProfile:syncTaskProfile];
-            if (stopDurationTracking) {
-                stopDurationTracking();
-            }
         }
 
         BOOL isInitialSync = !self.isEventStreamInitialised;

diff --git a/changelog.d/pr-1606.change b/changelog.d/pr-1606.change
@@ -0,0 +1 @@
+Crypto: Remove megolm decrypt cache build flag