Safe Haskell	None
Language	Haskell2010

Hasura.Backends.Postgres.Execute.Subscription

Description

Postgres Execute subscription

Multiplex is an optimization which allows us to group similar queries into a single query, and routing the response rows afterwards. See https://hasura.io/docs/latest/graphql/core/databases/postgres/subscriptions/execution-and-performance.html for more details

See Execute.

Synopsis

data QueryParametersInfo (b :: BackendType) = QueryParametersInfo {
- _qpiReusableVariableValues :: HashMap Name (ColumnValue b)
- _qpiSyntheticVariableValues :: Seq (ColumnValue b)
- _qpiReferencedSessionVariables :: HashSet SessionVariable
}
qpiSyntheticVariableValues :: forall b. Lens' (QueryParametersInfo b) (Seq (ColumnValue b))
qpiReusableVariableValues :: forall b. Lens' (QueryParametersInfo b) (HashMap Name (ColumnValue b))
qpiReferencedSessionVariables :: forall b. Lens' (QueryParametersInfo b) (HashSet SessionVariable)
validateVariables :: forall pgKind f m. (Traversable f, MonadError QErr m, MonadIO m) => PGExecCtx -> f (ColumnValue ('Postgres pgKind)) -> m (ValidatedVariables f)
newtype MultiplexedQuery = MultiplexedQuery {
- unMultiplexedQuery :: Query
}
toSQLFromItem :: (Backend ('Postgres pgKind), PostgresAnnotatedFieldJSON pgKind) => TableAlias -> QueryDB ('Postgres pgKind) Void SQLExp -> FromItem
mkMultiplexedQuery :: (Backend ('Postgres pgKind), PostgresAnnotatedFieldJSON pgKind) => InsOrdHashMap Name (QueryDB ('Postgres pgKind) Void SQLExp) -> MultiplexedQuery
mkStreamingMultiplexedQuery :: (Backend ('Postgres pgKind), PostgresAnnotatedFieldJSON pgKind) => (Name, QueryDB ('Postgres pgKind) Void SQLExp) -> MultiplexedQuery
resolveMultiplexedValue :: (MonadState (QueryParametersInfo ('Postgres pgKind)) m, MonadError QErr m) => SessionVariables -> UnpreparedValue ('Postgres pgKind) -> m SQLExp
executeMultiplexedQuery :: MonadTx m => MultiplexedQuery -> [(CohortId, CohortVariables)] -> m [(CohortId, ByteString)]
executeStreamingMultiplexedQuery :: MonadTx m => MultiplexedQuery -> [(CohortId, CohortVariables)] -> m [(CohortId, ByteString, AltJ CursorVariableValues)]
executeQuery :: (MonadTx m, FromRow a) => Query -> [(CohortId, CohortVariables)] -> m [a]

Documentation

data QueryParametersInfo (b :: BackendType) Source #

Internal: Used to collect information about various parameters of a subscription field's AST as we resolve them to SQL expressions.

Constructors

QueryParametersInfo
Fields _qpiReusableVariableValues :: HashMap Name (ColumnValue b) _qpiSyntheticVariableValues :: Seq (ColumnValue b) _qpiReferencedSessionVariables :: HashSet SessionVariable The session variables that are referenced in the query root fld's AST. This information is used to determine a cohort's required session variables

Instances

Instances details

Generic (QueryParametersInfo b) Source #
Instance details Defined in Hasura.Backends.Postgres.Execute.Subscription Associated Types type Rep (QueryParametersInfo b) :: Type -> Type # Methods from :: QueryParametersInfo b -> Rep (QueryParametersInfo b) x # to :: Rep (QueryParametersInfo b) x -> QueryParametersInfo b #
Semigroup (QueryParametersInfo b) Source #
Instance details Defined in Hasura.Backends.Postgres.Execute.Subscription Methods (<>) :: QueryParametersInfo b -> QueryParametersInfo b -> QueryParametersInfo b # sconcat :: NonEmpty (QueryParametersInfo b) -> QueryParametersInfo b # stimes :: Integral b0 => b0 -> QueryParametersInfo b -> QueryParametersInfo b #
Monoid (QueryParametersInfo b) Source #
Instance details Defined in Hasura.Backends.Postgres.Execute.Subscription Methods mempty :: QueryParametersInfo b # mappend :: QueryParametersInfo b -> QueryParametersInfo b -> QueryParametersInfo b # mconcat :: [QueryParametersInfo b] -> QueryParametersInfo b #
type Rep (QueryParametersInfo b) Source #
Instance details Defined in Hasura.Backends.Postgres.Execute.Subscription type Rep (QueryParametersInfo b) = D1 ('MetaData "QueryParametersInfo" "Hasura.Backends.Postgres.Execute.Subscription" "graphql-engine-1.0.0-inplace" 'False) (C1 ('MetaCons "QueryParametersInfo" 'PrefixI 'True) (S1 ('MetaSel ('Just "_qpiReusableVariableValues") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedStrict) (Rec0 (HashMap Name (ColumnValue b))) :: (S1 ('MetaSel ('Just "_qpiSyntheticVariableValues") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedStrict) (Rec0 (Seq (ColumnValue b))) :: S1 ('MetaSel ('Just "_qpiReferencedSessionVariables") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedStrict) (Rec0 (HashSet SessionVariable)))))

qpiSyntheticVariableValues :: forall b. Lens' (QueryParametersInfo b) (Seq (ColumnValue b)) Source #

qpiReusableVariableValues :: forall b. Lens' (QueryParametersInfo b) (HashMap Name (ColumnValue b)) Source #

qpiReferencedSessionVariables :: forall b. Lens' (QueryParametersInfo b) (HashSet SessionVariable) Source #

validateVariables :: forall pgKind f m. (Traversable f, MonadError QErr m, MonadIO m) => PGExecCtx -> f (ColumnValue ('Postgres pgKind)) -> m (ValidatedVariables f) Source #

Checks if the provided arguments are valid values for their corresponding types. | Generates SQL of the format "select v1::t1, v2::t2 ..."

newtype MultiplexedQuery Source #

Constructors

MultiplexedQuery
Fields unMultiplexedQuery :: Query

Instances

Instances details

Eq MultiplexedQuery Source #
Instance details Defined in Hasura.Backends.Postgres.Execute.Subscription Methods (==) :: MultiplexedQuery -> MultiplexedQuery -> Bool # (/=) :: MultiplexedQuery -> MultiplexedQuery -> Bool #
Hashable MultiplexedQuery Source #
Instance details Defined in Hasura.Backends.Postgres.Execute.Subscription Methods hashWithSalt :: Int -> MultiplexedQuery -> Int hash :: MultiplexedQuery -> Int
ToTxt MultiplexedQuery Source #
Instance details Defined in Hasura.Backends.Postgres.Execute.Subscription Methods toTxt :: MultiplexedQuery -> Text Source #

toSQLFromItem :: (Backend ('Postgres pgKind), PostgresAnnotatedFieldJSON pgKind) => TableAlias -> QueryDB ('Postgres pgKind) Void SQLExp -> FromItem Source #

mkMultiplexedQuery :: (Backend ('Postgres pgKind), PostgresAnnotatedFieldJSON pgKind) => InsOrdHashMap Name (QueryDB ('Postgres pgKind) Void SQLExp) -> MultiplexedQuery Source #

mkStreamingMultiplexedQuery :: (Backend ('Postgres pgKind), PostgresAnnotatedFieldJSON pgKind) => (Name, QueryDB ('Postgres pgKind) Void SQLExp) -> MultiplexedQuery Source #

resolveMultiplexedValue :: (MonadState (QueryParametersInfo ('Postgres pgKind)) m, MonadError QErr m) => SessionVariables -> UnpreparedValue ('Postgres pgKind) -> m SQLExp Source #

Resolves an UnresolvedVal by converting UVPG values to SQL expressions that refer to the result_vars input object, collecting information about various parameters of the query along the way.

executeMultiplexedQuery :: MonadTx m => MultiplexedQuery -> [(CohortId, CohortVariables)] -> m [(CohortId, ByteString)] Source #

executeStreamingMultiplexedQuery :: MonadTx m => MultiplexedQuery -> [(CohortId, CohortVariables)] -> m [(CohortId, ByteString, AltJ CursorVariableValues)] Source #

executeQuery :: (MonadTx m, FromRow a) => Query -> [(CohortId, CohortVariables)] -> m [a] Source #

Internal; used by both executeMultiplexedQuery, executeStreamingMultiplexedQuery and pgDBSubscriptionExplain.