chatdesk-ui/postgrest_v12.2.8/src/PostgREST/Query.hs

317 lines
15 KiB
Haskell

{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE RecordWildCards #-}
-- TODO: This module shouldn't depend on SchemaCache
module PostgREST.Query
( QueryResult (..)
, runQuery
) where
import Control.Monad.Except (liftEither)
import qualified Data.Aeson as JSON
import qualified Data.Aeson.KeyMap as KM
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy.Char8 as LBS
import Data.Either.Combinators (mapLeft)
import qualified Data.HashMap.Strict as HM
import qualified Data.Set as S
import qualified Hasql.Decoders as HD
import qualified Hasql.DynamicStatements.Snippet as SQL (Snippet)
import qualified Hasql.DynamicStatements.Statement as SQL
import qualified Hasql.Transaction as SQL
import qualified Hasql.Transaction.Sessions as SQL
import qualified PostgREST.ApiRequest.Types as ApiRequestTypes
import qualified PostgREST.AppState as AppState
import qualified PostgREST.Error as Error
import qualified PostgREST.Query.QueryBuilder as QueryBuilder
import qualified PostgREST.Query.Statements as Statements
import qualified PostgREST.RangeQuery as RangeQuery
import qualified PostgREST.SchemaCache as SchemaCache
import PostgREST.ApiRequest (ApiRequest (..),
Mutation (..))
import PostgREST.ApiRequest.Preferences (PreferCount (..),
PreferHandling (..),
PreferMaxAffected (..),
PreferTimezone (..),
PreferTransaction (..),
Preferences (..),
shouldCount)
import PostgREST.Auth (AuthResult (..))
import PostgREST.Config (AppConfig (..),
OpenAPIMode (..))
import PostgREST.Config.PgVersion (PgVersion (..))
import PostgREST.Error (Error)
import PostgREST.MediaType (MediaType (..))
import PostgREST.Plan (ActionPlan (..),
CallReadPlan (..),
CrudPlan (..),
DbActionPlan (..),
InfoPlan (..),
InspectPlan (..))
import PostgREST.Plan.MutatePlan (MutatePlan (..))
import PostgREST.Plan.ReadPlan (ReadPlanTree)
import PostgREST.Query.SqlFragment (escapeIdentList, fromQi,
intercalateSnippet,
setConfigWithConstantName,
setConfigWithConstantNameJSON,
setConfigWithDynamicName)
import PostgREST.Query.Statements (ResultSet (..))
import PostgREST.SchemaCache (SchemaCache (..))
import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..))
import PostgREST.SchemaCache.Routine (MediaHandler, Routine (..),
RoutineMap)
import PostgREST.SchemaCache.Table (TablesMap)
import Protolude hiding (Handler)
type DbHandler = ExceptT Error SQL.Transaction
data QueryResult
= DbCrudResult CrudPlan ResultSet
| DbCallResult CallReadPlan ResultSet
| MaybeDbResult InspectPlan (Maybe (TablesMap, RoutineMap, Maybe Text))
| NoDbResult InfoPlan
-- TODO This function needs to be free from IO, only App.hs should do IO
runQuery :: AppState.AppState -> AppConfig -> AuthResult -> ApiRequest -> ActionPlan -> SchemaCache -> PgVersion -> Bool -> ExceptT Error IO QueryResult
runQuery _ _ _ _ (NoDb x) _ _ _ = pure $ NoDbResult x
runQuery appState config AuthResult{..} apiReq (Db plan) sCache pgVer authenticated = do
dbResp <- lift $ do
let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction
AppState.usePool appState (transaction isoLvl txMode $ runExceptT dbHandler)
resp <-
liftEither . mapLeft Error.PgErr $
mapLeft (Error.PgError authenticated) dbResp
liftEither resp
where
prepared = configDbPreparedStatements config
isoLvl = planIsoLvl config authRole plan
txMode = planTxMode plan
dbHandler = do
setPgLocals plan config authClaims authRole apiReq
runPreReq config
actionQuery plan config apiReq pgVer sCache
planTxMode :: DbActionPlan -> SQL.Mode
planTxMode (DbCrud x) = pTxMode x
planTxMode (DbCall x) = crTxMode x
planTxMode (MaybeDb x) = ipTxmode x
planIsoLvl :: AppConfig -> ByteString -> DbActionPlan -> SQL.IsolationLevel
planIsoLvl AppConfig{configRoleIsoLvl} role actPlan = case actPlan of
DbCall CallReadPlan{crProc} -> fromMaybe roleIsoLvl $ pdIsoLvl crProc
_ -> roleIsoLvl
where
roleIsoLvl = HM.findWithDefault SQL.ReadCommitted role configRoleIsoLvl
actionQuery :: DbActionPlan -> AppConfig -> ApiRequest -> PgVersion -> SchemaCache -> DbHandler QueryResult
actionQuery (DbCrud plan@WrappedReadPlan{..}) conf@AppConfig{..} apiReq@ApiRequest{iPreferences=Preferences{..}} _ _ = do
let countQuery = QueryBuilder.readPlanToCountQuery wrReadPlan
resultSet <-
lift . SQL.statement mempty $
Statements.prepareRead
(QueryBuilder.readPlanToQuery wrReadPlan)
(if preferCount == Just EstimatedCount then
-- LIMIT maxRows + 1 so we can determine below that maxRows was surpassed
QueryBuilder.limitedQuery countQuery ((+ 1) <$> configDbMaxRows)
else
countQuery
)
(shouldCount preferCount)
wrMedia
wrHandler
configDbPreparedStatements
failNotSingular wrMedia resultSet
optionalRollback conf apiReq
DbCrudResult plan <$> resultSetWTotal conf apiReq resultSet countQuery
actionQuery (DbCrud plan@MutateReadPlan{mrMutation=MutationCreate, ..}) conf apiReq _ _ = do
resultSet <- writeQuery mrReadPlan mrMutatePlan mrMedia mrHandler apiReq conf
failNotSingular mrMedia resultSet
optionalRollback conf apiReq
pure $ DbCrudResult plan resultSet
actionQuery (DbCrud plan@MutateReadPlan{mrMutation=MutationUpdate, ..}) conf apiReq@ApiRequest{iPreferences=Preferences{..}, ..} _ _ = do
resultSet <- writeQuery mrReadPlan mrMutatePlan mrMedia mrHandler apiReq conf
failNotSingular mrMedia resultSet
failExceedsMaxAffectedPref (preferMaxAffected,preferHandling) resultSet
failsChangesOffLimits (RangeQuery.rangeLimit iTopLevelRange) resultSet
optionalRollback conf apiReq
pure $ DbCrudResult plan resultSet
actionQuery (DbCrud plan@MutateReadPlan{mrMutation=MutationSingleUpsert, ..}) conf apiReq _ _ = do
resultSet <- writeQuery mrReadPlan mrMutatePlan mrMedia mrHandler apiReq conf
failPut resultSet
optionalRollback conf apiReq
pure $ DbCrudResult plan resultSet
actionQuery (DbCrud plan@MutateReadPlan{mrMutation=MutationDelete, ..}) conf apiReq@ApiRequest{iPreferences=Preferences{..}, ..} _ _ = do
resultSet <- writeQuery mrReadPlan mrMutatePlan mrMedia mrHandler apiReq conf
failNotSingular mrMedia resultSet
failExceedsMaxAffectedPref (preferMaxAffected,preferHandling) resultSet
failsChangesOffLimits (RangeQuery.rangeLimit iTopLevelRange) resultSet
optionalRollback conf apiReq
pure $ DbCrudResult plan resultSet
actionQuery (DbCall plan@CallReadPlan{..}) conf@AppConfig{..} apiReq@ApiRequest{iPreferences=Preferences{..}} pgVer _ = do
resultSet <-
lift . SQL.statement mempty $
Statements.prepareCall
crProc
(QueryBuilder.callPlanToQuery crCallPlan pgVer)
(QueryBuilder.readPlanToQuery crReadPlan)
(QueryBuilder.readPlanToCountQuery crReadPlan)
(shouldCount preferCount)
crMedia
crHandler
configDbPreparedStatements
optionalRollback conf apiReq
failNotSingular crMedia resultSet
failExceedsMaxAffectedPref (preferMaxAffected,preferHandling) resultSet
pure $ DbCallResult plan resultSet
actionQuery (MaybeDb plan@InspectPlan{ipSchema=tSchema}) AppConfig{..} _ pgVer sCache =
lift $ case configOpenApiMode of
OAFollowPriv -> do
tableAccess <- SQL.statement [tSchema] (SchemaCache.accessibleTables pgVer configDbPreparedStatements)
MaybeDbResult plan . Just <$> ((,,)
(HM.filterWithKey (\qi _ -> S.member qi tableAccess) $ SchemaCache.dbTables sCache)
<$> SQL.statement (tSchema, configDbHoistedTxSettings) (SchemaCache.accessibleFuncs pgVer configDbPreparedStatements)
<*> SQL.statement tSchema (SchemaCache.schemaDescription configDbPreparedStatements))
OAIgnorePriv ->
MaybeDbResult plan . Just <$> ((,,)
(HM.filterWithKey (\(QualifiedIdentifier sch _) _ -> sch == tSchema) $ SchemaCache.dbTables sCache)
(HM.filterWithKey (\(QualifiedIdentifier sch _) _ -> sch == tSchema) $ SchemaCache.dbRoutines sCache)
<$> SQL.statement tSchema (SchemaCache.schemaDescription configDbPreparedStatements))
OADisabled ->
pure $ MaybeDbResult plan Nothing
writeQuery :: ReadPlanTree -> MutatePlan -> MediaType -> MediaHandler -> ApiRequest -> AppConfig -> DbHandler ResultSet
writeQuery readPlan mutatePlan mType mHandler ApiRequest{iPreferences=Preferences{..}} conf =
let
(isPut, isInsert, pkCols) = case mutatePlan of {Insert{where_,insPkCols} -> ((not . null) where_, True, insPkCols); _ -> (False,False, mempty);}
in
lift . SQL.statement mempty $
Statements.prepareWrite
(QueryBuilder.readPlanToQuery readPlan)
(QueryBuilder.mutatePlanToQuery mutatePlan)
isInsert
isPut
mType
mHandler
preferRepresentation
preferResolution
pkCols
(configDbPreparedStatements conf)
-- Makes sure the querystring pk matches the payload pk
-- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted,
-- PUT /items?id=eq.14 { "id" : 2, .. } is rejected.
-- If this condition is not satisfied then nothing is inserted,
-- check the WHERE for INSERT in QueryBuilder.hs to see how it's done
failPut :: ResultSet -> DbHandler ()
failPut RSPlan{} = pure ()
failPut RSStandard{rsQueryTotal=queryTotal} =
when (queryTotal /= 1) $ do
lift SQL.condemn
throwError $ Error.ApiRequestError ApiRequestTypes.PutMatchingPkError
resultSetWTotal :: AppConfig -> ApiRequest -> ResultSet -> SQL.Snippet -> DbHandler ResultSet
resultSetWTotal _ _ rs@RSPlan{} _ = return rs
resultSetWTotal AppConfig{..} ApiRequest{iPreferences=Preferences{..}} rs@RSStandard{rsTableTotal=tableTotal} countQuery =
case preferCount of
Just PlannedCount -> do
total <- explain
return rs{rsTableTotal=total}
Just EstimatedCount ->
if tableTotal > (fromIntegral <$> configDbMaxRows) then do
total <- max tableTotal <$> explain
return rs{rsTableTotal=total}
else
return rs
Just ExactCount ->
return rs
Nothing ->
return rs
where
explain =
lift . SQL.statement mempty . Statements.preparePlanRows countQuery $
configDbPreparedStatements
-- |
-- Fail a response if a single JSON object was requested and not exactly one
-- was found.
failNotSingular :: MediaType -> ResultSet -> DbHandler ()
failNotSingular _ RSPlan{} = pure ()
failNotSingular mediaType RSStandard{rsQueryTotal=queryTotal} =
when (elem mediaType [MTVndSingularJSON True, MTVndSingularJSON False] && queryTotal /= 1) $ do
lift SQL.condemn
throwError $ Error.ApiRequestError . ApiRequestTypes.SingularityError $ toInteger queryTotal
failExceedsMaxAffectedPref :: (Maybe PreferMaxAffected, Maybe PreferHandling) -> ResultSet -> DbHandler ()
failExceedsMaxAffectedPref (Nothing,_) _ = pure ()
failExceedsMaxAffectedPref _ RSPlan{} = pure ()
failExceedsMaxAffectedPref (Just (PreferMaxAffected n), handling) RSStandard{rsQueryTotal=queryTotal} = when ((queryTotal > n) && (handling == Just Strict)) $ do
lift SQL.condemn
throwError $ Error.ApiRequestError . ApiRequestTypes.MaxAffectedViolationError $ toInteger queryTotal
failsChangesOffLimits :: Maybe Integer -> ResultSet -> DbHandler ()
failsChangesOffLimits _ RSPlan{} = pure ()
failsChangesOffLimits Nothing _ = pure ()
failsChangesOffLimits (Just maxChanges) RSStandard{rsQueryTotal=queryTotal} =
when (queryTotal > fromIntegral maxChanges) $ do
lift SQL.condemn
throwError $ Error.ApiRequestError $ ApiRequestTypes.OffLimitsChangesError queryTotal maxChanges
-- | Set a transaction to roll back if requested
optionalRollback :: AppConfig -> ApiRequest -> DbHandler ()
optionalRollback AppConfig{..} ApiRequest{iPreferences=Preferences{..}} = do
lift $ when (shouldRollback || (configDbTxRollbackAll && not shouldCommit)) $ do
SQL.sql "SET CONSTRAINTS ALL IMMEDIATE"
SQL.condemn
where
shouldCommit =
preferTransaction == Just Commit
shouldRollback =
preferTransaction == Just Rollback
-- | Set transaction scoped settings
setPgLocals :: DbActionPlan -> AppConfig -> KM.KeyMap JSON.Value -> BS.ByteString -> ApiRequest -> DbHandler ()
setPgLocals dbActPlan AppConfig{..} claims role ApiRequest{..} = lift $
SQL.statement mempty $ SQL.dynamicallyParameterized
-- To ensure `GRANT SET ON PARAMETER <superuser_setting> TO authenticator` works, the role settings must be set before the impersonated role.
-- Otherwise the GRANT SET would have to be applied to the impersonated role. See https://github.com/PostgREST/postgrest/issues/3045
("select " <> intercalateSnippet ", " (searchPathSql : roleSettingsSql ++ roleSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ timezoneSql ++ funcSettingsSql ++ appSettingsSql))
HD.noResult configDbPreparedStatements
where
methodSql = setConfigWithConstantName ("request.method", iMethod)
pathSql = setConfigWithConstantName ("request.path", iPath)
headersSql = setConfigWithConstantNameJSON "request.headers" iHeaders
cookiesSql = setConfigWithConstantNameJSON "request.cookies" iCookies
claimsSql = [setConfigWithConstantName ("request.jwt.claims", LBS.toStrict $ JSON.encode claims)]
roleSql = [setConfigWithConstantName ("role", role)]
roleSettingsSql = setConfigWithDynamicName <$> HM.toList (fromMaybe mempty $ HM.lookup role configRoleSettings)
appSettingsSql = setConfigWithDynamicName <$> (join bimap toUtf8 <$> configAppSettings)
timezoneSql = maybe mempty (\(PreferTimezone tz) -> [setConfigWithConstantName ("timezone", tz)]) $ preferTimezone iPreferences
funcSettingsSql = setConfigWithDynamicName <$> (join bimap toUtf8 <$> funcSettings)
searchPathSql =
let schemas = escapeIdentList (iSchema : configDbExtraSearchPath) in
setConfigWithConstantName ("search_path", schemas)
funcSettings = case dbActPlan of
DbCall CallReadPlan{crProc} -> pdFuncSettings crProc
_ -> mempty
-- | Runs the pre-request function.
runPreReq :: AppConfig -> DbHandler ()
runPreReq conf = lift $ traverse_ (SQL.statement mempty . stmt) (configDbPreRequest conf)
where
stmt req = SQL.dynamicallyParameterized
("select " <> fromQi req <> "()")
HD.noResult
(configDbPreparedStatements conf)