[pgmq] use Paths_haskell_pgmq for pgmq.sql

haskell-pgmq.cabal

@@ -66,6 +66,9 @@ library
                     , Database.PGMQ.Schema
                     , Database.PGMQ.Simple
                     , Database.PGMQ.Types
+                    
+    other-modules:
+                    , Paths_haskell_pgmq
 
     -- Modules included in this library but not exported.
     -- other-modules:
@@ -79,9 +82,7 @@ library
                     , bytestring >= 0.11 && < 0.13
                     , postgresql-simple >= 0.6 && < 0.8
                     , safe >= 0.3 && < 0.4
-                    , template-haskell >= 2.19.0.0 && < 2.20
                     , text >= 1.2 && < 2.2
-                    , th-utilities >= 0.2.5.0 && < 0.3
                     , time >= 1.10 && < 1.15
                     , units >= 2.4 && < 2.5
 

src/Database/PGMQ/Schema.hs

-{-# LANGUAGE TemplateHaskell #-}
-
 module Database.PGMQ.Schema where
 
-import Language.Haskell.TH.Syntax (lift)
-import TH.RelativePaths (qReadFileString)
+import Paths_haskell_pgmq
 
 
-pgmqSchema :: String
-pgmqSchema = $(qReadFileString "sql/pgmq.sql" >>= lift)
+pgmqSchema :: IO String
+pgmqSchema = do
+  f <- getDataFileName "sql/pgmq.sql"
+  readFile f

src/Database/PGMQ/Simple.hs

@@ -57,13 +57,14 @@ import Safe (headMay)
 {-| Initialize PGMQ given a PostgreSQL connection. Mainly concerned
     with creating the 'pgmq' extension. -}
 initialize :: PSQL.Connection -> IO ()
-initialize conn =
+initialize conn = do
   -- OK so this is a bit tricky because of the usage of IF NOT EXISTS:
   -- https://stackoverflow.com/questions/29900845/create-schema-if-not-exists-raises-duplicate-key-error
   -- PostgreSQL will complain badly if 'initialize' is called
   -- from multiple threads at once.
   -- Hence, we use 'pg_advisory_xact_lock' to lock ourselves
   -- out of this situation.
+  pgmqSchema' <- pgmqSchema
   PSQL.withTransaction conn $ do
     let magicLockId = 1122334455 :: Int
     _ <- PSQL.query conn [sql| SELECT pg_advisory_xact_lock(?) |] (PSQL.Only magicLockId) :: IO [PSQL.Only ()]
@@ -75,7 +76,7 @@ initialize conn =
         -- extension by only running the SQL, not using `CREATE
         -- EXTENSION`. But it works and is quite hassle-free
         void $ PSQL.execute_ conn [sql|CREATE SCHEMA pgmq |]
-        void $ PSQL.execute_ conn (fromString pgmqSchema)
+        void $ PSQL.execute_ conn (fromString pgmqSchema')
     -- void $ PSQL.execute_ conn [sql| CREATE EXTENSION IF NOT EXISTS pgmq |]