chatai/postgrest_v12.2.8/src/PostgREST/SchemaCache/Routine.hs

155 lines
5.4 KiB
Haskell

{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveGeneric #-}
module PostgREST.SchemaCache.Routine
( PgType(..)
, Routine(..)
, RoutineParam(..)
, FuncVolatility(..)
, FuncSettings
, RoutineMap
, RetType(..)
, funcReturnsScalar
, funcReturnsSetOfScalar
, funcReturnsSingleComposite
, funcReturnsVoid
, funcTableName
, funcReturnsCompositeAlias
, funcReturnsSingle
, MediaHandlerMap
, ResolvedHandler
, MediaHandler(..)
) where
import Data.Aeson ((.=))
import qualified Data.Aeson as JSON
import qualified Data.HashMap.Strict as HM
import qualified Hasql.Transaction.Sessions as SQL
import qualified PostgREST.MediaType as MediaType
import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..),
RelIdentifier (..), Schema,
TableName)
import Protolude
data PgType
= Scalar QualifiedIdentifier
| Composite QualifiedIdentifier Bool -- True if the composite is a domain alias(used to work around a bug in pg 11 and 12, see QueryBuilder.hs)
deriving (Eq, Show, Ord, Generic, JSON.ToJSON)
data RetType
= Single PgType
| SetOf PgType
deriving (Eq, Show, Ord, Generic, JSON.ToJSON)
data FuncVolatility
= Volatile
| Stable
| Immutable
deriving (Eq, Show, Ord, Generic, JSON.ToJSON)
type FuncSettings = [(Text,Text)]
data Routine = Function
{ pdSchema :: Schema
, pdName :: Text
, pdDescription :: Maybe Text
, pdParams :: [RoutineParam]
, pdReturnType :: RetType
, pdVolatility :: FuncVolatility
, pdHasVariadic :: Bool
, pdIsoLvl :: Maybe SQL.IsolationLevel
, pdFuncSettings :: FuncSettings
}
deriving (Eq, Show, Generic)
-- need to define JSON manually bc SQL.IsolationLevel doesn't have a JSON instance(and we can't define one for that type without getting a compiler error)
instance JSON.ToJSON Routine where
toJSON (Function sch nam desc params ret vol hasVar _ sets) = JSON.object
[
"pdSchema" .= sch
, "pdName" .= nam
, "pdDescription" .= desc
, "pdParams" .= JSON.toJSON params
, "pdReturnType" .= JSON.toJSON ret
, "pdVolatility" .= JSON.toJSON vol
, "pdHasVariadic" .= JSON.toJSON hasVar
, "pdFuncSettings" .= JSON.toJSON sets
]
data RoutineParam = RoutineParam
{ ppName :: Text
, ppType :: Text
, ppTypeMaxLength :: Text
, ppReq :: Bool
, ppVar :: Bool
}
deriving (Eq, Show, Ord, Generic, JSON.ToJSON)
-- Order by least number of params in the case of overloaded functions
instance Ord Routine where
Function schema1 name1 des1 prms1 rt1 vol1 hasVar1 iso1 sets1 `compare` Function schema2 name2 des2 prms2 rt2 vol2 hasVar2 iso2 sets2
| schema1 == schema2 && name1 == name2 && length prms1 < length prms2 = LT
| schema2 == schema2 && name1 == name2 && length prms1 > length prms2 = GT
| otherwise = (schema1, name1, des1, prms1, rt1, vol1, hasVar1, iso1, sets1) `compare` (schema2, name2, des2, prms2, rt2, vol2, hasVar2, iso2, sets2)
-- | A map of all procs, all of which can be overloaded(one entry will have more than one Routine).
-- | It uses a HashMap for a faster lookup.
type RoutineMap = HM.HashMap QualifiedIdentifier [Routine]
-- | A media handler can be an aggregate over a composite type or a function over a scalar
data MediaHandler
-- non overridable builtins
= BuiltinAggSingleJson Bool
| BuiltinAggArrayJsonStrip
-- these builtins are overridable
| BuiltinOvAggJson
| BuiltinOvAggGeoJson
| BuiltinOvAggCsv
-- custom
| CustomFunc QualifiedIdentifier RelIdentifier
| NoAgg
deriving (Eq, Show, Generic, JSON.ToJSON)
funcReturnsSingle :: Routine -> Bool
funcReturnsSingle proc = case proc of
Function{pdReturnType = Single _} -> True
_ -> False
funcReturnsScalar :: Routine -> Bool
funcReturnsScalar proc = case proc of
Function{pdReturnType = Single (Scalar{})} -> True
_ -> False
funcReturnsSetOfScalar :: Routine -> Bool
funcReturnsSetOfScalar proc = case proc of
Function{pdReturnType = SetOf (Scalar{})} -> True
_ -> False
funcReturnsCompositeAlias :: Routine -> Bool
funcReturnsCompositeAlias proc = case proc of
Function{pdReturnType = Single (Composite _ True)} -> True
Function{pdReturnType = SetOf (Composite _ True)} -> True
_ -> False
funcReturnsSingleComposite :: Routine -> Bool
funcReturnsSingleComposite proc = case proc of
Function{pdReturnType = Single (Composite _ _)} -> True
_ -> False
funcReturnsVoid :: Routine -> Bool
funcReturnsVoid proc = case proc of
Function{pdReturnType = Single (Scalar (QualifiedIdentifier "pg_catalog" "void"))} -> True
_ -> False
funcTableName :: Routine -> Maybe TableName
funcTableName proc = case pdReturnType proc of
SetOf (Composite qi _) -> Just $ qiName qi
Single (Composite qi _) -> Just $ qiName qi
_ -> Nothing
-- the resolved handler also carries the media type because MTAny (*/*) is resolved to a different media type
type ResolvedHandler = (MediaHandler, MediaType.MediaType)
type MediaHandlerMap = HM.HashMap (RelIdentifier, MediaType.MediaType) ResolvedHandler