graphql-engine/server/src-lib/Hasura/SQL/Value.hs
2020-02-11 16:02:13 +05:30

217 lines
7.6 KiB
Haskell

module Hasura.SQL.Value
( PGScalarValue(..)
, pgColValueToInt
, withConstructorFn
, parsePGValue
, TxtEncodedPGVal(..)
, txtEncodedPGVal
, binEncoder
, txtEncoder
, toBinaryValue
, toTxtValue
, toPrepParam
) where
import Hasura.SQL.GeoJSON
import Hasura.SQL.Time
import Hasura.SQL.Types
import qualified Database.PG.Query as Q
import qualified Database.PG.Query.PTI as PTI
import qualified Hasura.SQL.DML as S
import Data.Aeson
import Data.Int
import Data.Scientific
import Data.Time
import Hasura.Prelude
import qualified Data.Aeson.Text as AE
import qualified Data.Aeson.Types as AT
import qualified Data.ByteString as B
import qualified Data.Text as T
import qualified Data.Text.Conversions as TC
import qualified Data.Text.Encoding as TE
import qualified Data.Text.Lazy as TL
import qualified Database.PostgreSQL.LibPQ as PQ
import qualified PostgreSQL.Binary.Encoding as PE
newtype RasterWKB
= RasterWKB { getRasterWKB :: TC.Base16 B.ByteString }
deriving (Show, Eq)
instance FromJSON RasterWKB where
parseJSON = \case
String t -> case TC.fromText t of
Just v -> return $ RasterWKB v
Nothing -> fail
"invalid hexadecimal representation of raster well known binary format"
_ -> fail "expecting String for raster"
-- Binary value. Used in prepared sq
data PGScalarValue
= PGValInteger !Int32
| PGValSmallInt !Int16
| PGValBigInt !Int64
| PGValFloat !Float
| PGValDouble !Double
| PGValNumeric !Scientific
| PGValBoolean !Bool
| PGValChar !Char
| PGValVarchar !T.Text
| PGValText !T.Text
| PGValCitext !T.Text
| PGValDate !Day
| PGValTimeStampTZ !UTCTime
| PGValTimeTZ !ZonedTimeOfDay
| PGNull !PGScalarType
| PGValJSON !Q.JSON
| PGValJSONB !Q.JSONB
| PGValGeo !GeometryWithCRS
| PGValRaster !RasterWKB
| PGValUnknown !T.Text
deriving (Show, Eq)
pgColValueToInt :: PGScalarValue -> Maybe Int
pgColValueToInt (PGValInteger i) = Just $ fromIntegral i
pgColValueToInt (PGValSmallInt i) = Just $ fromIntegral i
pgColValueToInt (PGValBigInt i) = Just $ fromIntegral i
pgColValueToInt _ = Nothing
withConstructorFn :: PGScalarType -> S.SQLExp -> S.SQLExp
withConstructorFn ty v
| isGeoType ty = S.SEFnApp "ST_GeomFromGeoJSON" [v] Nothing
| ty == PGRaster = S.SEFnApp "ST_RastFromHexWKB" [v] Nothing
| otherwise = v
parsePGValue :: PGScalarType -> Value -> AT.Parser PGScalarValue
parsePGValue ty val = case (ty, val) of
(_ , Null) -> pure $ PGNull ty
(PGUnknown _, String t) -> pure $ PGValUnknown t
(PGRaster , _) -> parseTyped -- strictly parse raster value
(_ , String t) -> parseTyped <|> pure (PGValUnknown t)
(_ , _) -> parseTyped
where
parseTyped = case ty of
PGSmallInt -> PGValSmallInt <$> parseJSON val
PGInteger -> PGValInteger <$> parseJSON val
PGBigInt -> PGValBigInt <$> parseJSON val
PGSerial -> PGValInteger <$> parseJSON val
PGBigSerial -> PGValBigInt <$> parseJSON val
PGFloat -> PGValFloat <$> parseJSON val
PGDouble -> PGValDouble <$> parseJSON val
PGNumeric -> PGValNumeric <$> parseJSON val
PGBoolean -> PGValBoolean <$> parseJSON val
PGChar -> PGValChar <$> parseJSON val
PGVarchar -> PGValVarchar <$> parseJSON val
PGText -> PGValText <$> parseJSON val
PGCitext -> PGValCitext <$> parseJSON val
PGDate -> PGValDate <$> parseJSON val
PGTimeStampTZ -> PGValTimeStampTZ <$> parseJSON val
PGTimeTZ -> PGValTimeTZ <$> parseJSON val
PGJSON -> PGValJSON . Q.JSON <$> parseJSON val
PGJSONB -> PGValJSONB . Q.JSONB <$> parseJSON val
PGGeometry -> PGValGeo <$> parseJSON val
PGGeography -> PGValGeo <$> parseJSON val
PGRaster -> PGValRaster <$> parseJSON val
PGUnknown tyName ->
fail $ "A string is expected for type : " ++ T.unpack tyName
data TxtEncodedPGVal
= TENull
| TELit !Text
deriving (Show, Eq, Generic)
instance Hashable TxtEncodedPGVal
instance ToJSON TxtEncodedPGVal where
toJSON = \case
TENull -> Null
TELit t -> String t
instance FromJSON TxtEncodedPGVal where
parseJSON Null = pure TENull
parseJSON (String t) = pure $ TELit t
parseJSON v = AT.typeMismatch "String" v
txtEncodedPGVal :: PGScalarValue -> TxtEncodedPGVal
txtEncodedPGVal colVal = case colVal of
PGValInteger i -> TELit $ T.pack $ show i
PGValSmallInt i -> TELit $ T.pack $ show i
PGValBigInt i -> TELit $ T.pack $ show i
PGValFloat f -> TELit $ T.pack $ show f
PGValDouble d -> TELit $ T.pack $ show d
PGValNumeric sc -> TELit $ T.pack $ show sc
PGValBoolean b -> TELit $ bool "false" "true" b
PGValChar t -> TELit $ T.pack $ show t
PGValVarchar t -> TELit t
PGValText t -> TELit t
PGValCitext t -> TELit t
PGValDate d -> TELit $ T.pack $ showGregorian d
PGValTimeStampTZ u ->
TELit $ T.pack $ formatTime defaultTimeLocale "%FT%T%QZ" u
PGValTimeTZ (ZonedTimeOfDay tod tz) ->
TELit $ T.pack (show tod ++ timeZoneOffsetString tz)
PGNull _ ->
TENull
PGValJSON (Q.JSON j) -> TELit $ TL.toStrict $
AE.encodeToLazyText j
PGValJSONB (Q.JSONB j) -> TELit $ TL.toStrict $
AE.encodeToLazyText j
PGValGeo o -> TELit $ TL.toStrict $
AE.encodeToLazyText o
PGValRaster r -> TELit $ TC.toText $ getRasterWKB r
PGValUnknown t -> TELit t
binEncoder :: PGScalarValue -> Q.PrepArg
binEncoder colVal = case colVal of
PGValInteger i -> Q.toPrepVal i
PGValSmallInt i -> Q.toPrepVal i
PGValBigInt i -> Q.toPrepVal i
PGValFloat f -> Q.toPrepVal f
PGValDouble d -> Q.toPrepVal d
PGValNumeric sc -> Q.toPrepVal sc
PGValBoolean b -> Q.toPrepVal b
PGValChar t -> Q.toPrepVal t
PGValVarchar t -> Q.toPrepVal t
PGValText t -> Q.toPrepVal t
PGValCitext t -> Q.toPrepVal t
PGValDate d -> Q.toPrepVal d
PGValTimeStampTZ u -> Q.toPrepVal u
PGValTimeTZ (ZonedTimeOfDay t z) -> Q.toPrepValHelper PTI.timetz PE.timetz_int (t, z)
PGNull ty -> (pgTypeOid ty, Nothing)
PGValJSON u -> Q.toPrepVal u
PGValJSONB u -> Q.toPrepVal u
PGValGeo o -> Q.toPrepVal $ TL.toStrict $ AE.encodeToLazyText o
PGValRaster r -> Q.toPrepVal $ TC.toText $ getRasterWKB r
PGValUnknown t -> (PTI.auto, Just (TE.encodeUtf8 t, PQ.Text))
txtEncoder :: PGScalarValue -> S.SQLExp
txtEncoder colVal = case txtEncodedPGVal colVal of
TENull -> S.SENull
TELit t -> S.SELit t
{- Note [Type casting prepared params]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Prepared values are passed to Postgres via text encoding. Explicit type cast for prepared params
is needed to distinguish the column types. For example, the parameter for citext column type is
generated as ($i)::citext where 'i' is parameter position (integer).
Also see https://github.com/hasura/graphql-engine/issues/2818
-}
toPrepParam :: Int -> PGScalarType -> S.SQLExp
toPrepParam i ty =
-- See Note [Type casting prepared params] above
S.withTyAnn ty . withConstructorFn ty $ S.SEPrep i
toBinaryValue :: WithScalarType PGScalarValue -> Q.PrepArg
toBinaryValue = binEncoder . pstValue
toTxtValue :: WithScalarType PGScalarValue -> S.SQLExp
toTxtValue (WithScalarType ty val) =
S.withTyAnn ty . withConstructorFn ty $ txtEncoder val