graphql-engine/server/src-lib/Hasura/Backends/Postgres/SQL/Value.hs
Auke Booij 9fb80d1230 server: remove some unused top-level definitions; some minor code cleanups (#141)
GitOrigin-RevId: 92002684c5d89791a05975e4b137d93599491ffa
2020-12-04 19:33:10 +00:00

302 lines
11 KiB
Haskell

module Hasura.Backends.Postgres.SQL.Value
( PGScalarValue(..)
, pgScalarValueToJson
, withConstructorFn
, parsePGValue
, scientificToInteger
, scientificToFloat
, TxtEncodedPGVal(..)
, txtEncodedPGVal
, binEncoder
, txtEncoder
, toPrepParam
) where
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 Data.UUID as UUID
import qualified Database.PG.Query as Q
import qualified Database.PG.Query.PTI as PTI
import qualified Database.PostgreSQL.LibPQ as PQ
import qualified PostgreSQL.Binary.Encoding as PE
import Data.Aeson
import Data.Int
import Data.Scientific
import Data.Time
import qualified Hasura.Backends.Postgres.SQL.DML as S
import Hasura.Backends.Postgres.SQL.Types
import Hasura.SQL.GeoJSON
import Hasura.SQL.Time
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"
instance ToJSON RasterWKB where
toJSON = toJSON . TC.toText . getRasterWKB
-- Binary value. Used in prepared sq
data PGScalarValue
= PGValInteger !Int32
| PGValSmallInt !Int16
| PGValBigInt !Int64
| PGValFloat !Float
| PGValDouble !Double
| PGValNumeric !Scientific
| PGValMoney !Scientific
| PGValBoolean !Bool
| PGValChar !Char
| PGValVarchar !Text
| PGValText !Text
| PGValCitext !Text
| PGValDate !Day
| PGValTimeStamp !LocalTime
| PGValTimeStampTZ !UTCTime
| PGValTimeTZ !ZonedTimeOfDay
| PGNull !PGScalarType
| PGValJSON !Q.JSON
| PGValJSONB !Q.JSONB
| PGValGeo !GeometryWithCRS
| PGValRaster !RasterWKB
| PGValUUID !UUID.UUID
| PGValUnknown !Text
deriving (Show, Eq)
pgScalarValueToJson :: PGScalarValue -> Value
pgScalarValueToJson = \case
PGValInteger i -> toJSON i
PGValSmallInt i -> toJSON i
PGValBigInt i -> toJSON i
PGValFloat f -> toJSON f
PGValDouble d -> toJSON d
PGValNumeric sc -> toJSON sc
PGValMoney m -> toJSON m
PGValBoolean b -> toJSON b
PGValChar t -> toJSON t
PGValVarchar t -> toJSON t
PGValText t -> toJSON t
PGValCitext t -> toJSON t
PGValDate d -> toJSON d
PGValTimeStamp u ->
toJSON $ formatTime defaultTimeLocale "%FT%T%QZ" u
PGValTimeStampTZ u ->
toJSON $ formatTime defaultTimeLocale "%FT%T%QZ" u
PGValTimeTZ (ZonedTimeOfDay tod tz) ->
toJSON (show tod ++ timeZoneOffsetString tz)
PGNull _ -> Null
PGValJSON (Q.JSON j) -> j
PGValJSONB (Q.JSONB j) -> j
PGValGeo o -> toJSON o
PGValRaster r -> toJSON r
PGValUUID u -> toJSON u
PGValUnknown t -> toJSON t
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
scientificToInteger :: (Integral i, Bounded i) => Scientific -> AT.Parser i
scientificToInteger num =
toBoundedInteger num
`onNothing`
fail ("The value " ++ show num ++ " lies outside the "
++ "bounds or is not an integer. Maybe it is a "
++ "float, or is there integer overflow?")
scientificToFloat :: (RealFloat f) => Scientific -> AT.Parser f
scientificToFloat num =
toBoundedRealFloat num
`onLeft` \ _ ->
fail ("The value " ++ show num ++ " lies outside the "
++ "bounds. Is it overflowing the float bounds?")
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
parseBoundedInt :: forall i. (Integral i, Bounded i) => Value -> AT.Parser i
parseBoundedInt = withScientific ("Integer expected for input type: " ++ show ty) scientificToInteger
parseBoundedFloat :: forall a. (RealFloat a) => Value -> AT.Parser a
parseBoundedFloat = withScientific ("Float expected for input type: " ++ show ty) scientificToFloat
parseTyped = case ty of
PGSmallInt -> PGValSmallInt <$> parseBoundedInt val
PGInteger -> PGValInteger <$> parseBoundedInt val
PGBigInt -> PGValBigInt <$> parseBoundedInt val
PGSerial -> PGValInteger <$> parseBoundedInt val
PGBigSerial -> PGValBigInt <$> parseBoundedInt val
PGFloat -> PGValFloat <$> parseBoundedFloat val
PGDouble -> PGValDouble <$> parseBoundedFloat val
PGNumeric -> PGValNumeric <$> parseJSON val
PGMoney -> PGValMoney <$> parseJSON val
PGBoolean -> PGValBoolean <$> parseJSON val
PGChar -> PGValChar <$> parseJSON val
PGVarchar -> PGValVarchar <$> parseJSON val
PGText -> PGValText <$> parseJSON val
PGCitext -> PGValCitext <$> parseJSON val
PGDate -> PGValDate <$> parseJSON val
PGTimeStamp -> PGValTimeStamp <$> 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 <$> parseJSON val
PGUUID -> PGValUUID <$> 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 = \case
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
-- PostgreSQL doesn't like scientific notation for money, so pass it
-- with 2 decimal places.
PGValMoney m -> TELit $ T.pack $ formatScientific Fixed (Just 2) m
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
PGValTimeStamp u ->
TELit $ T.pack $ formatTime defaultTimeLocale "%FT%T%QZ" u
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
PGValUUID u -> TELit $ UUID.toText u
PGValUnknown t -> TELit t
pgTypeOid :: PGScalarType -> PQ.Oid
pgTypeOid = \case
PGSmallInt -> PTI.int2
PGInteger -> PTI.int4
PGBigInt -> PTI.int8
PGSerial -> PTI.int4
PGBigSerial -> PTI.int8
PGFloat -> PTI.float4
PGDouble -> PTI.float8
PGNumeric -> PTI.numeric
PGMoney -> PTI.numeric
PGBoolean -> PTI.bool
PGChar -> PTI.char
PGVarchar -> PTI.varchar
PGText -> PTI.text
PGCitext -> PTI.text -- Explict type cast to citext needed, See also Note [Type casting prepared params]
PGDate -> PTI.date
PGTimeStamp -> PTI.timestamp
PGTimeStampTZ -> PTI.timestamptz
PGTimeTZ -> PTI.timetz
PGJSON -> PTI.json
PGJSONB -> PTI.jsonb
PGGeometry -> PTI.text -- we are using the ST_GeomFromGeoJSON($i) instead of $i
PGGeography -> PTI.text
PGRaster -> PTI.text -- we are using the ST_RastFromHexWKB($i) instead of $i
PGUUID -> PTI.uuid
(PGUnknown _) -> PTI.auto
binEncoder :: PGScalarValue -> Q.PrepArg
binEncoder = \case
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
PGValMoney m -> Q.toPrepVal m
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
PGValTimeStamp u -> Q.toPrepVal u
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
PGValUUID u -> Q.toPrepVal u
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