Add 'DB' for 'TxSet'

lib/wallet/src/Cardano/Wallet/DB/Store/Transactions/Layer.hs

@@ -0,0 +1,51 @@
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies #-}
+
+{- |
+Copyright: © 2022 IOHK
+License: Apache-2.0
+
+Implementation of a 'DB' for 'TxSet'.
+
+-}
+module Cardano.Wallet.DB.Store.Transactions.Layer
+    ( ReadTxSet (..)
+    , mkDBTxSet
+    ) where
+
+import Prelude
+
+import Cardano.Wallet.DB
+    ( DB (..), untry )
+import Cardano.Wallet.DB.Sqlite.Types
+    ( TxId )
+import Cardano.Wallet.DB.Store.Transactions.Model
+    ( DeltaTxSet, TxRelation )
+import Data.DBVar
+    ( Store (..) )
+import Database.Persist.Sql
+    ( SqlPersistT )
+
+import qualified Cardano.Wallet.DB.Store.Transactions.Store as TxSet
+
+{-----------------------------------------------------------------------------
+    DB for 'TxSet'
+------------------------------------------------------------------------------}
+data ReadTxSet b where
+    GetByTxId :: TxId -> ReadTxSet (Maybe TxRelation)
+
+-- | Implementation of a 'DB' for 'TxSet'.
+mkDBTxSet :: DB (SqlPersistT IO) ReadTxSet DeltaTxSet
+mkDBTxSet = DB
+    { readDB = \case
+        GetByTxId txid -> TxSet.selectTx txid
+    , loadDB = untry loadS
+    , writeDB = writeS
+    , updateDB = TxSet.updateTxSet
+    }
+  where
+    Store{loadS,writeS} = TxSet.mkStoreTransactions