Allow custo configuration of Datasync limits

IHP/DataSync/Controller.hs

@@ -386,22 +386,30 @@ findTransactionById transactionId = do
 -- concurrent transactions. Then all database connections are removed from the connection pool and further database
 -- queries for other users will fail.
 --
-ensureBelowTransactionLimit :: (?state :: IORef DataSyncController) => IO ()
+ensureBelowTransactionLimit :: (?state :: IORef DataSyncController, ?context :: ControllerContext) => IO ()
 ensureBelowTransactionLimit = do
     transactions <- get #transactions <$> readIORef ?state
     let transactionCount = HashMap.size transactions
-    let maxTransactionsPerConnection = 10
     when (transactionCount >= maxTransactionsPerConnection) do
         error ("You've reached the transaction limit of " <> tshow maxTransactionsPerConnection <> " transactions")
 
-ensureBelowSubscriptionsLimit :: (?state :: IORef DataSyncController) => IO ()
+ensureBelowSubscriptionsLimit :: (?state :: IORef DataSyncController, ?context :: ControllerContext) => IO ()
 ensureBelowSubscriptionsLimit = do
     subscriptions <- get #subscriptions <$> readIORef ?state
     let subscriptionsCount = HashMap.size subscriptions
-    let maxSubscriptionsPerConnection = 128
     when (subscriptionsCount >= maxSubscriptionsPerConnection) do
         error ("You've reached the subscriptions limit of " <> tshow maxSubscriptionsPerConnection <> " subscriptions")
 
+maxTransactionsPerConnection :: _ => Int
+maxTransactionsPerConnection = 
+    case getAppConfig @DataSyncMaxTransactionsPerConnection of
+        DataSyncMaxTransactionsPerConnection value -> value
+
+maxSubscriptionsPerConnection :: _ => Int
+maxSubscriptionsPerConnection = 
+    case getAppConfig @DataSyncMaxSubscriptionsPerConnection of
+        DataSyncMaxSubscriptionsPerConnection value -> value
+
 sqlQueryWithRLSAndTransactionId ::
     ( ?modelContext :: ModelContext
     , PG.ToRow parameters

IHP/FrameworkConfig.hs

@@ -73,6 +73,9 @@ newtype AssetVersion = AssetVersion Text
 
 newtype CustomMiddleware = CustomMiddleware Middleware
 
+newtype DataSyncMaxSubscriptionsPerConnection = DataSyncMaxSubscriptionsPerConnection Int
+newtype DataSyncMaxTransactionsPerConnection = DataSyncMaxTransactionsPerConnection Int
+
 -- | Puts an option into the current configuration
 --
 -- In case an option already exists with the same type, it will not be overriden:
@@ -156,6 +159,11 @@ ihpDefaultConfig = do
     option $ RLSAuthenticatedRole rlsAuthenticatedRole
 
     initAssetVersion
+
+    dataSyncMaxSubscriptionsPerConnection <- envOrDefault "IHP_DATASYNC_MAX_SUBSCRIPTIONS_PER_CONNECTION" 128
+    dataSyncMaxTransactionsPerConnection <- envOrDefault "IHP_DATASYNC_MAX_TRANSACTIONS_PER_CONNECTION" 10
+    option $ DataSyncMaxSubscriptionsPerConnection dataSyncMaxSubscriptionsPerConnection
+    option $ DataSyncMaxTransactionsPerConnection dataSyncMaxTransactionsPerConnection
 
     option $ CustomMiddleware id