graphql-engine/server/src-lib/Hasura/Backends/BigQuery/Plan.hs
Antoine Leblanc 2152911e24 server: introduce Hasura.Base (take 2)
GitOrigin-RevId: 0dd10f1ccd338b1cf382ebff59b6ee7f209d39a1
2021-05-11 15:19:33 +00:00

95 lines
3.2 KiB
Haskell

-- | Planning T-SQL queries and subscriptions.
module Hasura.Backends.BigQuery.Plan
( planNoPlan
, planToForest
) where
import Hasura.Prelude
import qualified Data.Text.Lazy as LT
import Control.Monad.Validate
import Data.Aeson.Text
import Data.Text.Extended
import Data.Tree
import qualified Hasura.Backends.BigQuery.DataLoader.Plan as DataLoader
import qualified Hasura.Base.Error as E
import qualified Hasura.GraphQL.Parser as GraphQL
import qualified Hasura.RQL.Types.Column as RQL
import Hasura.Backends.BigQuery.FromIr as BigQuery
import Hasura.Backends.BigQuery.Types as BigQuery
import Hasura.GraphQL.Context
import Hasura.SQL.Backend
import Hasura.SQL.Types
import Hasura.Session
-- --------------------------------------------------------------------------------
-- -- Top-level planner
planToForest ::
MonadError E.QErr m
=> UserInfo
-> QueryDB 'BigQuery (GraphQL.UnpreparedValue 'BigQuery)
-> m (Forest DataLoader.PlannedAction)
planToForest userInfo qrf = do
select <- planNoPlan userInfo qrf
let (!_headAndTail, !plannedActionsList) =
DataLoader.runPlan
(DataLoader.planSelectHeadAndTail Nothing Nothing select)
!actionsForest = DataLoader.actionsForest id plannedActionsList
pure actionsForest
planNoPlan ::
MonadError E.QErr m
=> UserInfo
-> QueryDB 'BigQuery (GraphQL.UnpreparedValue 'BigQuery)
-> m Select
planNoPlan userInfo queryDB = do
rootField <- traverseQueryDB (prepareValueNoPlan (_uiSession userInfo)) queryDB
select <-
runValidate (BigQuery.runFromIr (BigQuery.fromRootField rootField))
`onLeft` (E.throw400 E.NotSupported . (tshow :: NonEmpty Error -> Text))
pure
select
{ selectFor =
case selectFor select of
NoFor -> NoFor
JsonFor forJson -> JsonFor forJson {jsonRoot = Root "root"}
}
--------------------------------------------------------------------------------
-- Resolving values
-- | Prepare a value without any query planning; we just execute the
-- query with the values embedded.
prepareValueNoPlan ::
(MonadError E.QErr m)
=> SessionVariables
-> GraphQL.UnpreparedValue 'BigQuery
-> m BigQuery.Expression
prepareValueNoPlan sessionVariables =
\case
GraphQL.UVLiteral x -> pure x
GraphQL.UVSession -> pure globalSessionExpression
-- To be honest, I'm not sure if it's indeed the JSON_VALUE operator we need here...
GraphQL.UVSessionVar typ text ->
case typ of
CollectableTypeScalar scalarType ->
pure
(CastExpression
(JsonValueExpression
globalSessionExpression
(FieldPath RootPath (toTxt text)))
scalarType)
CollectableTypeArray {} ->
throwError $ E.internalError "Cannot currently prepare array types in BigQuery."
GraphQL.UVParameter _ RQL.ColumnValue {..} -> pure (ValueExpression cvValue)
where
globalSessionExpression =
ValueExpression
(StringValue (LT.toStrict (encodeToLazyText sessionVariables)))