Use stm-containers Map in memory for concurrent read/writes

app/Main.hs

@@ -3,7 +3,7 @@
 
 module Main where
 
-import Soostone ( app, middleWare, AppState(AppState, sqliteFile) )
+import Soostone ( app, middleWare, AppState(AppState, sqliteFile, stmMap) )
 
 import Control.Monad ( void, when )
 import Data.Version (showVersion)
@@ -34,6 +34,7 @@ import Prometheus ( register )
 import Prometheus.Metric.GHC ( ghcMetrics )
 import Prometheus.Metric.Proc ( procMetrics )
 import Text.Read ( readEither )
+import qualified StmContainers.Map as SM
 
 
 versioner :: Parser (a -> a)
@@ -98,7 +99,8 @@ main = do
   case serverCommand of
     Run ServerConfig{..} -> do
       when (sqliteDB == ":memory:") $ fail "In-memory DB is not supported!"
-      let appState = AppState { sqliteFile = sqliteDB }
+      m <- SM.newIO
+      let appState = AppState { sqliteFile = sqliteDB, stmMap = m }
       void $ register ghcMetrics
       void $ register procMetrics
       run serverPort (middleWare $ app appState)