Use in memory cache when adding inBoundGroupSession

changelog.d/4011.bugfix

@@ -0,0 +1 @@
+Messages are displayed as unable to decrypt then decrypted a few seconds later #4011

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/InboundGroupSessionStore.kt

@@ -22,6 +22,7 @@ import kotlinx.coroutines.launch
 import org.matrix.android.sdk.api.extensions.tryOrNull
 import org.matrix.android.sdk.internal.crypto.model.OlmInboundGroupSessionWrapper2
 import org.matrix.android.sdk.internal.crypto.store.IMXCryptoStore
+import org.matrix.android.sdk.internal.session.SessionScope
 import org.matrix.android.sdk.internal.util.MatrixCoroutineDispatchers
 import timber.log.Timber
 import java.util.Timer
@@ -71,18 +72,24 @@ internal class InboundGroupSessionStore @Inject constructor(
     }
 
     @Synchronized
-    fun storeInBoundGroupSession(wrapper: OlmInboundGroupSessionWrapper2) {
+    fun storeInBoundGroupSession(wrapper: OlmInboundGroupSessionWrapper2, sessionId: String, senderKey: String) {
         Timber.v("## Inbound: getInboundGroupSession mark as dirty ${wrapper.roomId}-${wrapper.senderKey}")
         // We want to batch this a bit for performances
         dirtySession.add(wrapper)
 
+        if (sessionCache[CacheKey(sessionId, senderKey)] == null) {
+            // first time seen, put it in memory cache while waiting for batch insert
+            // If it's already known, no need to update cache it's already there
+            sessionCache.put(CacheKey(sessionId, senderKey), wrapper)
+        }
+
         timerTask?.cancel()
         timerTask = object : TimerTask() {
             override fun run() {
                 batchSave()
             }
         }
-        timer.schedule(timerTask!!, 2_000)
+        timer.schedule(timerTask!!, 300)
     }
 
     @Synchronized

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/MXOlmDevice.kt

@@ -577,7 +577,9 @@ internal class MXOlmDevice @Inject constructor(
         session.keysClaimed = keysClaimed
         session.forwardingCurve25519KeyChain = forwardingCurve25519KeyChain
 
-        store.storeInboundGroupSessions(listOf(session))
+
+        inboundGroupSessionStore.storeInBoundGroupSession(session, sessionId, senderKey)
+//        store.storeInboundGroupSessions(listOf(session))
 
         return true
     }
@@ -703,7 +705,7 @@ internal class MXOlmDevice @Inject constructor(
                 timelineSet.add(messageIndexKey)
             }
 
-            inboundGroupSessionStore.storeInBoundGroupSession(session)
+            inboundGroupSessionStore.storeInBoundGroupSession(session, sessionId, senderKey)
             val payload = try {
                 val adapter = MoshiProvider.providesMoshi().adapter<JsonDict>(JSON_DICT_PARAMETERIZED_TYPE)
                 val payloadString = convertFromUTF8(decryptResult.mDecryptedMessage)