graphql-engine/server/src-lib/Hasura/GraphQL/Execute/Query.hs
2019-11-26 17:44:21 +05:30

274 lines
9.5 KiB
Haskell

module Hasura.GraphQL.Execute.Query
( convertQuerySelSet
, queryOpFromPlan
, ReusableQueryPlan
, GeneratedSqlMap
, PreparedSql(..)
) where
import qualified Data.Aeson as J
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as LBS
import qualified Data.HashMap.Strict as Map
import qualified Data.IntMap as IntMap
import qualified Data.TByteString as TBS
import qualified Data.Text as T
import qualified Database.PG.Query as Q
import qualified Language.GraphQL.Draft.Syntax as G
import Control.Lens ((^?))
import Data.Has
import qualified Hasura.GraphQL.Resolve as R
import qualified Hasura.GraphQL.Transport.HTTP.Protocol as GH
import qualified Hasura.GraphQL.Validate as GV
import qualified Hasura.GraphQL.Validate.Field as V
import qualified Hasura.SQL.DML as S
import Hasura.EncJSON
import Hasura.GraphQL.Resolve.Types
import Hasura.GraphQL.Validate.Types
import Hasura.Prelude
import Hasura.RQL.DML.Select (asSingleRowJsonResp)
import Hasura.RQL.Types
import Hasura.SQL.Types
import Hasura.SQL.Value
type PlanVariables = Map.HashMap G.Variable Int
-- | The value is (Q.PrepArg, PGScalarValue) because we want to log the human-readable value of the
-- prepared argument and not the binary encoding in PG format
type PrepArgMap = IntMap.IntMap (Q.PrepArg, PGScalarValue)
data PGPlan
= PGPlan
{ _ppQuery :: !Q.Query
, _ppVariables :: !PlanVariables
, _ppPrepared :: !PrepArgMap
}
instance J.ToJSON PGPlan where
toJSON (PGPlan q vars prepared) =
J.object [ "query" J..= Q.getQueryText q
, "variables" J..= vars
, "prepared" J..= fmap show prepared
]
data RootFieldPlan
= RFPRaw !B.ByteString
| RFPPostgres !PGPlan
fldPlanFromJ :: (J.ToJSON a) => a -> RootFieldPlan
fldPlanFromJ = RFPRaw . LBS.toStrict . J.encode
instance J.ToJSON RootFieldPlan where
toJSON = \case
RFPRaw encJson -> J.toJSON $ TBS.fromBS encJson
RFPPostgres pgPlan -> J.toJSON pgPlan
type FieldPlans = [(G.Alias, RootFieldPlan)]
data ReusableQueryPlan
= ReusableQueryPlan
{ _rqpVariableTypes :: !ReusableVariableTypes
, _rqpFldPlans :: !FieldPlans
}
instance J.ToJSON ReusableQueryPlan where
toJSON (ReusableQueryPlan varTypes fldPlans) =
J.object [ "variables" J..= varTypes
, "field_plans" J..= fldPlans
]
withPlan
:: (MonadError QErr m)
=> UserVars -> PGPlan -> ReusableVariableValues -> m PreparedSql
withPlan usrVars (PGPlan q reqVars prepMap) annVars = do
prepMap' <- foldM getVar prepMap (Map.toList reqVars)
let args = withUserVars usrVars $ IntMap.elems prepMap'
return $ PreparedSql q args
where
getVar accum (var, prepNo) = do
let varName = G.unName $ G.unVariable var
colVal <- onNothing (Map.lookup var annVars) $
throw500 $ "missing variable in annVars : " <> varName
let prepVal = (toBinaryValue colVal, pstValue colVal)
return $ IntMap.insert prepNo prepVal accum
-- turn the current plan into a transaction
mkCurPlanTx
:: (MonadError QErr m)
=> UserVars
-> FieldPlans
-> m (LazyRespTx, GeneratedSqlMap)
mkCurPlanTx usrVars fldPlans = do
-- generate the SQL and prepared vars or the bytestring
resolved <- forM fldPlans $ \(alias, fldPlan) -> do
fldResp <- case fldPlan of
RFPRaw resp -> return $ RRRaw resp
RFPPostgres (PGPlan q _ prepMap) -> do
let args = withUserVars usrVars $ IntMap.elems prepMap
return $ RRSql $ PreparedSql q args
return (alias, fldResp)
return (mkLazyRespTx resolved, mkGeneratedSqlMap resolved)
withUserVars :: UserVars -> [(Q.PrepArg, PGScalarValue)] -> [(Q.PrepArg, PGScalarValue)]
withUserVars usrVars list =
let usrVarsAsPgScalar = PGValJSON $ Q.JSON $ J.toJSON usrVars
prepArg = Q.toPrepVal (Q.AltJ usrVars)
in (prepArg, usrVarsAsPgScalar):list
data PlanningSt
= PlanningSt
{ _psArgNumber :: !Int
, _psVariables :: !PlanVariables
, _psPrepped :: !PrepArgMap
}
initPlanningSt :: PlanningSt
initPlanningSt =
PlanningSt 2 Map.empty IntMap.empty
getVarArgNum :: (MonadState PlanningSt m) => G.Variable -> m Int
getVarArgNum var = do
PlanningSt curArgNum vars prepped <- get
case Map.lookup var vars of
Just argNum -> pure argNum
Nothing -> do
put $ PlanningSt (curArgNum + 1) (Map.insert var curArgNum vars) prepped
pure curArgNum
addPrepArg
:: (MonadState PlanningSt m)
=> Int -> (Q.PrepArg, PGScalarValue) -> m ()
addPrepArg argNum arg = do
PlanningSt curArgNum vars prepped <- get
put $ PlanningSt curArgNum vars $ IntMap.insert argNum arg prepped
getNextArgNum :: (MonadState PlanningSt m) => m Int
getNextArgNum = do
PlanningSt curArgNum vars prepped <- get
put $ PlanningSt (curArgNum + 1) vars prepped
return curArgNum
prepareWithPlan :: (MonadState PlanningSt m) => UnresolvedVal -> m S.SQLExp
prepareWithPlan = \case
R.UVPG annPGVal -> do
let AnnPGVal varM _ colVal = annPGVal
argNum <- case varM of
Just var -> getVarArgNum var
Nothing -> getNextArgNum
addPrepArg argNum (toBinaryValue colVal, pstValue colVal)
return $ toPrepParam argNum (pstType colVal)
R.UVSessVar ty sessVar -> do
let sessVarVal =
S.SEOpApp (S.SQLOp "->>")
[currentSession, S.SELit $ T.toLower sessVar]
return $ flip S.SETyAnn (S.mkTypeAnn ty) $ case ty of
PGTypeScalar colTy -> withConstructorFn colTy sessVarVal
PGTypeArray _ -> sessVarVal
R.UVSQL sqlExp -> pure sqlExp
R.UVSession -> pure currentSession
where
currentSession = S.SEPrep 1
queryRootName :: Text
queryRootName = "query_root"
convertQuerySelSet
:: ( MonadError QErr m
, MonadReader r m
, Has TypeMap r
, Has QueryCtxMap r
, Has FieldMap r
, Has OrdByCtx r
, Has SQLGenCtx r
, Has UserInfo r
)
=> QueryReusability
-> V.SelSet
-> m (LazyRespTx, Maybe ReusableQueryPlan, GeneratedSqlMap)
convertQuerySelSet initialReusability fields = do
usrVars <- asks (userVars . getter)
(fldPlans, finalReusability) <- runReusabilityTWith initialReusability $
forM (toList fields) $ \fld -> do
fldPlan <- case V._fName fld of
"__type" -> fldPlanFromJ <$> R.typeR fld
"__schema" -> fldPlanFromJ <$> R.schemaR fld
"__typename" -> pure $ fldPlanFromJ queryRootName
_ -> do
unresolvedAst <- R.queryFldToPGAST fld
(q, PlanningSt _ vars prepped) <- flip runStateT initPlanningSt $
R.traverseQueryRootFldAST prepareWithPlan unresolvedAst
pure . RFPPostgres $ PGPlan (R.toPGQuery q) vars prepped
pure (V._fAlias fld, fldPlan)
let varTypes = finalReusability ^? _Reusable
reusablePlan = ReusableQueryPlan <$> varTypes <*> pure fldPlans
(tx, sql) <- mkCurPlanTx usrVars fldPlans
pure (tx, reusablePlan, sql)
-- use the existing plan and new variables to create a pg query
queryOpFromPlan
:: (MonadError QErr m)
=> UserVars
-> Maybe GH.VariableValues
-> ReusableQueryPlan
-> m (LazyRespTx, GeneratedSqlMap)
queryOpFromPlan usrVars varValsM (ReusableQueryPlan varTypes fldPlans) = do
validatedVars <- GV.validateVariablesForReuse varTypes varValsM
-- generate the SQL and prepared vars or the bytestring
resolved <- forM fldPlans $ \(alias, fldPlan) ->
(alias,) <$> case fldPlan of
RFPRaw resp -> return $ RRRaw resp
RFPPostgres pgPlan -> RRSql <$> withPlan usrVars pgPlan validatedVars
return (mkLazyRespTx resolved, mkGeneratedSqlMap resolved)
data PreparedSql
= PreparedSql
{ _psQuery :: !Q.Query
, _psPrepArgs :: ![(Q.PrepArg, PGScalarValue)]
-- ^ The value is (Q.PrepArg, PGScalarValue) because we want to log the human-readable value of the
-- prepared argument (PGScalarValue) and not the binary encoding in PG format (Q.PrepArg)
}
-- | Required to log in `query-log`
instance J.ToJSON PreparedSql where
toJSON (PreparedSql q prepArgs) =
J.object [ "query" J..= Q.getQueryText q
, "prepared_arguments" J..= map (txtEncodedPGVal . snd) prepArgs
]
-- | Intermediate reperesentation of a computed SQL statement and prepared
-- arguments, or a raw bytestring (mostly, for introspection responses)
-- From this intermediate representation, a `LazyTx` can be generated, or the
-- SQL can be logged etc.
data ResolvedQuery
= RRRaw !B.ByteString
| RRSql !PreparedSql
-- | The computed SQL with alias which can be logged. Nothing here represents no
-- SQL for cases like introspection responses. Tuple of alias to a (maybe)
-- prepared statement
type GeneratedSqlMap = [(G.Alias, Maybe PreparedSql)]
mkLazyRespTx :: [(G.Alias, ResolvedQuery)] -> LazyRespTx
mkLazyRespTx resolved =
fmap encJFromAssocList $ forM resolved $ \(alias, node) -> do
resp <- case node of
RRRaw bs -> return $ encJFromBS bs
RRSql (PreparedSql q args) -> liftTx $ asSingleRowJsonResp q (map fst args)
return (G.unName $ G.unAlias alias, resp)
mkGeneratedSqlMap :: [(G.Alias, ResolvedQuery)] -> GeneratedSqlMap
mkGeneratedSqlMap resolved =
flip map resolved $ \(alias, node) ->
let res = case node of
RRRaw _ -> Nothing
RRSql ps -> Just ps
in (alias, res)