graphql-engine/server/src-lib/Hasura/GraphQL/Context.hs
Antoine Leblanc 8a77386fcf server: IR for DB-DB joins
### Description

This PR adds the required IR for DB to DB joins, based on @paf31 and @0x777 's `feature/db-to-db` branch.

To do so, it also refactors the IR to introduce a new type parameter, `r`, which is used to recursively constructs the `v` parameter of remote QueryDBs. When collecting remote joins, we replace `r` with `Const Void`, indicating at the type level that there cannot be any leftover remote join.

Furthermore, this PR refactors IR.Select for readability, moves some code from IR.Root to IR.Select to avoid having to deal with circular dependencies, and makes it compile by adding `error` in all new cases in the execution pipeline.

The diff doesn't make it clear, but most of Select.hs is actually unchanged. Declarations have just been reordered by topic, in the following order:
- type declarations
- instance declarations
- type aliases
- constructor functions
- traverse functions

https://github.com/hasura/graphql-engine-mono/pull/1580

Co-authored-by: Phil Freeman <630306+paf31@users.noreply.github.com>
GitOrigin-RevId: bbdcb4119cec8bb3fc32f1294f91b8dea0728721
2021-06-17 23:13:05 +00:00

43 lines
1.3 KiB
Haskell

{-# LANGUAGE StrictData #-}
module Hasura.GraphQL.Context
( RoleContext(..)
, GQLContext(..)
, ParserFn
) where
import Hasura.Prelude
import qualified Data.Aeson as J
import qualified Language.GraphQL.Draft.Syntax as G
import Data.Aeson.TH
import qualified Hasura.RQL.IR as IR
import Hasura.GraphQL.Parser
-- | For storing both a normal GQLContext and one for the backend variant.
-- Currently, this is to enable the backend variant to have certain insert
-- permissions which the frontend variant does not.
data RoleContext a
= RoleContext
{ _rctxDefault :: !a -- ^ The default context for normal sessions
, _rctxBackend :: !(Maybe a) -- ^ The context for sessions with backend privilege.
} deriving (Show, Eq, Functor, Foldable, Traversable)
$(deriveToJSON hasuraJSON ''RoleContext)
data GQLContext = GQLContext
{ gqlQueryParser :: ParserFn (InsOrdHashMap G.Name (IR.QueryRootField UnpreparedValue UnpreparedValue))
, gqlMutationParser :: Maybe (ParserFn (InsOrdHashMap G.Name (IR.MutationRootField UnpreparedValue UnpreparedValue)))
}
instance J.ToJSON GQLContext where
toJSON GQLContext{} = J.String "The GraphQL schema parsers"
type ParserFn a
= G.SelectionSet G.NoFragments Variable
-> Either (NESeq ParseError) (a, QueryReusability)