1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
|
{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE QuasiQuotes #-}
{-# OPTIONS_GHC -Wno-orphans #-}
module Postgres.MonadPostgres where
import Arg
import AtLeast (AtLeast)
import Control.Exception
( Exception (displayException),
Handler (Handler),
catches,
try,
)
import Control.Foldl qualified as Fold
import Control.Monad.Logger.CallStack (MonadLogger, logDebug, logWarn)
import Control.Monad.Reader (MonadReader (ask), ReaderT (..))
import Control.Monad.Trans.Resource
import Data.Aeson (FromJSON)
import Data.ByteString qualified as ByteString
import Data.Error.Tree
import Data.HashMap.Strict qualified as HashMap
import Data.Int (Int64)
import Data.List qualified as List
import Data.Pool (Pool)
import Data.Pool qualified as Pool
import Data.Text qualified as Text
import Data.Typeable (Typeable)
import Database.PostgreSQL.Simple (Connection, FormatError, FromRow, Query, QueryError, ResultError, SqlError, ToRow)
import Database.PostgreSQL.Simple qualified as PG
import Database.PostgreSQL.Simple qualified as Postgres
import Database.PostgreSQL.Simple.FromRow qualified as PG
import Database.PostgreSQL.Simple.ToField (ToField)
import Database.PostgreSQL.Simple.ToRow (ToRow (toRow))
import Database.PostgreSQL.Simple.Types (PGArray (PGArray), Query (..))
import GHC.IO.Handle (Handle)
import GHC.Records (getField)
import Label
import Language.Haskell.TH.Quote (QuasiQuoter)
import MyPrelude
import OpenTelemetry.Trace.Core (NewEvent (newEventName))
import OpenTelemetry.Trace.Core qualified as Otel hiding (inSpan, inSpan')
import OpenTelemetry.Trace.Monad qualified as Otel
import Postgres.Decoder
import Postgres.Decoder qualified as Dec
import Pretty (showPretty)
import PyF qualified
import Seconds
import System.Exit (ExitCode (..))
import Tool
import UnliftIO (MonadUnliftIO (withRunInIO), bracket, hClose, mask_)
import UnliftIO.Concurrent (forkIO)
import UnliftIO.Process (ProcessHandle)
import UnliftIO.Process qualified as Process
import UnliftIO.Resource qualified as Resource
import Prelude hiding (init, span)
-- | Postgres queries/commands that can be executed within a running transaction.
--
-- These are implemented with the @postgresql-simple@ primitives of the same name
-- and will behave the same unless othewise documented.
class (Monad m) => MonadPostgres (m :: Type -> Type) where
-- | Execute an INSERT, UPDATE, or other SQL query that is not expected to return results.
-- Returns the number of rows affected.
execute ::
(ToRow params, Typeable params) =>
Query ->
params ->
Transaction m (Label "numberOfRowsAffected" Natural)
-- | Execute a multi-row INSERT, UPDATE, or other SQL query that is not expected to return results.
--
-- Returns the number of rows affected. If the list of parameters is empty,
-- this function will simply return 0 without issuing the query to the backend.
-- If this is not desired, consider using the 'PG.Values' constructor instead.
executeMany ::
(ToRow params, Typeable params) =>
Query ->
NonEmpty params ->
Transaction m (Label "numberOfRowsAffected" Natural)
-- | Execute INSERT ... RETURNING, UPDATE ... RETURNING,
-- or other SQL query that accepts multi-row input and is expected to return results.
-- Note that it is possible to write query conn "INSERT ... RETURNING ..." ...
-- in cases where you are only inserting a single row,
-- and do not need functionality analogous to 'executeMany'.
--
-- If the list of parameters is empty, this function will simply return [] without issuing the query to the backend. If this is not desired, consider using the 'PG.Values' constructor instead.
executeManyReturningWith :: (ToRow q) => Query -> NonEmpty q -> Decoder r -> Transaction m [r]
-- | Run a query, passing parameters and result row parser.
queryWith ::
(PG.ToRow params, Typeable params, Typeable r) =>
PG.Query ->
params ->
Decoder r ->
Transaction m [r]
-- | Run a query without any parameters and result row parser.
queryWith_ ::
(Typeable r) =>
PG.Query ->
Decoder r ->
Transaction m [r]
-- | Run a query, passing parameters, and fold over the resulting rows.
--
-- This doesn’t have to realize the full list of results in memory,
-- rather results are streamed incrementally from the database.
--
-- When dealing with small results, it may be simpler (and perhaps faster) to use query instead.
--
-- This fold is _not_ strict. The stream consumer is responsible
-- for forcing the evaluation of its result to avoid space leaks.
--
-- If you can, prefer aggregating in the database itself.
foldRowsWithAcc ::
(ToRow params, Typeable row, Typeable params) =>
Query ->
params ->
Decoder row ->
a ->
(a -> row -> Transaction m a) ->
Transaction m a
-- | Run a given transaction in a transaction block, rolling back the transaction
-- if any exception (postgres or Haskell Exception) is thrown during execution.
--
-- Re-throws the exception.
--
-- Don’t do any long-running things on the Haskell side during a transaction,
-- because it will block a database connection and potentially also lock
-- database tables from being written or read by other clients.
--
-- Nonetheless, try to push transactions as far out to the handlers as possible,
-- don’t do something like @runTransaction $ query …@, because it will lead people
-- to accidentally start nested transactions (the inner transaction is run on a new connections,
-- thus can’t see any changes done by the outer transaction).
-- Only handlers should run transactions.
runTransaction :: Transaction m a -> m a
-- | Quasi-Quoter for multi-line SQL literals. Trims leading whitespace up to the least-indented line.
sql :: QuasiQuoter
sql = PyF.fmtTrim
-- | Run a query, passing parameters. Prefer 'queryWith' if possible.
query ::
forall m params r.
(PG.ToRow params, PG.FromRow r, Typeable params, Typeable r, MonadPostgres m) =>
PG.Query ->
params ->
Transaction m [r]
query qry params = queryWith qry params (Decoder PG.fromRow)
-- | Run a query without any parameters. Prefer 'queryWith' if possible.
--
-- TODO: I think(?) this can always be replaced by passing @()@ to 'query', remove?
query_ ::
forall m r.
(Typeable r, PG.FromRow r, MonadPostgres m) =>
PG.Query ->
Transaction m [r]
query_ qry = queryWith_ qry (Decoder PG.fromRow)
-- TODO: implement via fold, so that the result doesn’t have to be realized in memory
querySingleRow ::
( MonadPostgres m,
ToRow qParams,
Typeable qParams,
FromRow a,
Typeable a,
MonadThrow m
) =>
Query ->
qParams ->
Transaction m a
querySingleRow qry params = do
query qry params >>= ensureSingleRow
-- TODO: implement via fold, so that the result doesn’t have to be realized in memory
querySingleRowWith ::
( MonadPostgres m,
ToRow qParams,
Typeable qParams,
Typeable a,
MonadThrow m
) =>
Query ->
qParams ->
Decoder a ->
Transaction m a
querySingleRowWith qry params decoder = do
queryWith qry params decoder >>= ensureSingleRow
-- | Return the first row, if any.
queryFirstRowWithMaybe ::
( MonadPostgres m,
ToRow qParams,
Typeable qParams,
Typeable a
) =>
Query ->
qParams ->
Decoder a ->
Transaction m (Maybe a)
queryFirstRowWithMaybe qry params decoder = do
queryWith qry params decoder >>= \case
[] -> pure Nothing
(one : _) -> pure $ Just one
-- TODO: implement via fold, so that the result doesn’t have to be realized in memory
querySingleRowMaybe ::
( MonadPostgres m,
ToRow qParams,
Typeable qParams,
FromRow a,
Typeable a,
MonadThrow m
) =>
Query ->
qParams ->
Transaction m (Maybe a)
querySingleRowMaybe qry params = do
rows <- query qry params
case rows of
[] -> pure Nothing
[one] -> pure (Just one)
-- TODO: Should we MonadThrow this here? It’s really an implementation detail of MonadPostgres
-- that a database function can error out, should probably handled by the instances.
more -> throwM $ SingleRowError {numberOfRowsReturned = (List.length more)}
ensureSingleRow ::
(MonadThrow m) =>
[a] ->
m a
ensureSingleRow = \case
-- TODO: Should we MonadThrow this here? It’s really an implementation detail of MonadPostgres
-- that a database function can error out, should probably handled by the instances.
[] -> throwM (SingleRowError {numberOfRowsReturned = 0})
[one] -> pure one
more ->
throwM $
SingleRowError
{ numberOfRowsReturned =
-- TODO: this is VERY bad, because it requires to parse the full database output, even if there’s 10000000000 elements
List.length more
}
ensureNoneOrSingleRow ::
(MonadThrow m) =>
[a] ->
m (Maybe a)
ensureNoneOrSingleRow = \case
-- TODO: Should we MonadThrow this here? It’s really an implementation detail of MonadPostgres
-- that a database function can error out, should probably handled by the instances.
[] -> pure Nothing
[one] -> pure $ Just one
more ->
throwM $
SingleRowError
{ numberOfRowsReturned =
-- TODO: this is VERY bad, because it requires to parse the full database output, even if there’s 10000000000 elements
List.length more
}
-- | Run a query, passing parameters, and fold over the resulting rows.
--
-- This doesn’t have to realize the full list of results in memory,
-- rather results are streamed incrementally from the database.
--
-- When dealing with small results, it may be simpler (and perhaps faster) to use query instead.
--
-- The results are folded strictly into the Monoid returned by the decoder.
--
-- If you need more complex folding logic, use 'foldRowsWith' with a 'Fold'.
--
-- If you can, prefer aggregating in the database itself.
foldRowsWithMonoid ::
forall row params m.
( MonadPostgres m,
PG.ToRow params,
Typeable row,
Typeable params,
Monoid row
) =>
PG.Query ->
params ->
Decoder row ->
Transaction m row
foldRowsWithMonoid qry params decoder = foldRowsWith qry params decoder Fold.mconcat
-- | Run a query, passing parameters, and fold over the resulting rows.
--
-- This doesn’t have to realize the full list of results in memory,
-- rather results are streamed incrementally from the database.
--
-- When dealing with small results, it may be simpler (and perhaps faster) to use query instead.
--
-- The results are folded strictly by the 'Fold.Fold' that is passed.
--
-- If you can, prefer aggregating in the database itself.
foldRowsWith ::
forall row params m b.
( MonadPostgres m,
PG.ToRow params,
Typeable row,
Typeable params
) =>
PG.Query ->
params ->
Decoder row ->
Fold.Fold row b ->
Transaction m b
foldRowsWith qry params decoder = Fold.purely f
where
f :: forall x. (x -> row -> x) -> x -> (x -> b) -> Transaction m b
f acc init extract = do
x <- foldRowsWithAcc qry params decoder init (\a r -> pure $ acc a r)
pure $ extract x
newtype Transaction m a = Transaction {unTransaction :: (ReaderT Connection m a)}
deriving newtype
( Functor,
Applicative,
Monad,
MonadThrow,
MonadLogger,
MonadIO,
MonadUnliftIO,
MonadTrans,
Otel.MonadTracer
)
-- | [Resource Pool](http://hackage.haskell.org/package/resource-pool-0.2.3.2/docs/Data-Pool.html) configuration.
data PoolingInfo = PoolingInfo
{ -- | Minimal amount of resources that are
-- always available.
numberOfStripes :: AtLeast 1 Int,
-- | Time after which extra resources
-- (above minimum) can stay in the pool
-- without being used.
unusedResourceOpenTime :: Seconds,
-- | Max number of resources that can be
-- in the Pool at any time
maxOpenResourcesAcrossAllStripes :: AtLeast 1 Int
}
deriving stock (Generic, Eq, Show)
deriving anyclass (FromJSON)
initMonadPostgres ::
(Text -> IO ()) ->
-- | Info describing the connection to the Postgres DB
Postgres.ConnectInfo ->
-- | Configuration info for pooling attributes
PoolingInfo ->
-- | Created Postgres connection pool
ResourceT IO (Pool Postgres.Connection)
initMonadPostgres logInfoFn connectInfo poolingInfo = do
(_releaseKey, connPool) <-
Resource.allocate
(logInfoFn "Creating Postgres Connection Pool" >> createPGConnPool)
(\pool -> logInfoFn "Destroying Postgres Connection Pool" >> destroyPGConnPool pool)
pure connPool
where
-- \| Create a Postgres connection pool
createPGConnPool ::
IO (Pool Postgres.Connection)
createPGConnPool =
Pool.newPool $
Pool.defaultPoolConfig
{- resource init action -} poolCreateResource
{- resource destruction -} poolfreeResource
( poolingInfo.unusedResourceOpenTime.unSeconds
& fromIntegral @Natural @Double
)
(poolingInfo.maxOpenResourcesAcrossAllStripes.unAtLeast)
where
poolCreateResource = Postgres.connect connectInfo
poolfreeResource = Postgres.close
-- \| Destroy a Postgres connection pool
destroyPGConnPool ::
-- \| Pool to be destroyed
(Pool Postgres.Connection) ->
IO ()
destroyPGConnPool p = Pool.destroyAllResources p
-- | Improve a possible error message, by adding some context to it.
--
-- The given Exception type is caught, 'show'n and pretty-printed.
--
-- In case we get an `IOError`, we display it in a reasonable fashion.
addErrorInformation ::
forall exc a.
(Exception exc) =>
Text.Text ->
IO a ->
IO a
addErrorInformation msg io =
io
& try @exc
<&> first (showPretty >>> newError >>> errorContext msg)
& try @IOError
<&> first (showToError >>> errorContext "IOError" >>> errorContext msg)
<&> join @(Either Error)
>>= unwrapIOError
-- | Catch any Postgres exception that gets thrown,
-- print the query that was run and the query parameters,
-- then rethrow inside an 'Error'.
handlePGException ::
forall a params m.
( ToRow params,
MonadUnliftIO m,
MonadLogger m
) =>
PrettyPrintDatabaseQueries ->
Text ->
Query ->
-- | Depending on whether we used `format` or `formatMany`.
Either params (NonEmpty params) ->
IO a ->
Transaction m a
handlePGException prettyQuery queryType query' params io = do
withRunInIO $ \unliftIO ->
io
`catches` [ Handler $ unliftIO . logQueryException @SqlError,
Handler $ unliftIO . logQueryException @QueryError,
Handler $ unliftIO . logQueryException @ResultError,
Handler $ unliftIO . logFormatException
]
where
-- TODO: use throwInternalError here (after pulling it into the MonadPostgres class)
throwAsError = unwrapIOError . Left . newError
throwErr err = liftIO $ throwAsError $ prettyErrorTree $ nestedMultiError "A Postgres query failed" err
logQueryException :: (Exception e) => e -> Transaction m a
logQueryException exc = do
formattedQuery <-
case params of
Left one -> pgFormatQuery' prettyQuery query' one
Right many -> pgFormatQueryMany' prettyQuery query' many
throwErr
( singleError [fmt|Query Type: {queryType}|]
:| [ nestedError "Exception" (exc & showPretty & newError & singleError),
nestedError "Query" (formattedQuery & bytesToTextUtf8Lenient & newError & singleError)
]
)
logFormatException :: FormatError -> Transaction m a
logFormatException fe = throwErr (fe & showPretty & newError & singleError & singleton)
-- | Perform a Postgres action within a transaction
withPGTransaction ::
-- | Postgres connection pool to be used for the action
(Pool Postgres.Connection) ->
-- | DB-action to be performed
(Postgres.Connection -> IO a) ->
-- | Result of the DB-action
IO a
withPGTransaction connPool f =
Pool.withResource
connPool
(\conn -> Postgres.withTransaction conn (f conn))
-- | `pg_formatter` is a perl script that does not support any kind of streaming.
-- Thus we initialize a pool with a bunch of these scripts running, waiting for input. This way we can have somewhat fast SQL formatting.
--
-- Call `initPgFormatPool` to initialize, then use `runPgFormat` to format some sql.
data PgFormatPool = PgFormatPool
{ pool :: Pool PgFormatProcess,
pgFormat :: Tool
}
data PgFormatProcess = PgFormatProcess
{ stdinHdl :: Handle,
stdoutHdl :: Handle,
stderrHdl :: Handle,
procHdl :: ProcessHandle,
startedAt :: Otel.Timestamp
}
initPgFormatPool :: (HasField "pgFormat" tools Tool) => tools -> IO PgFormatPool
initPgFormatPool tools = do
pool <-
Pool.newPool
( Pool.defaultPoolConfig
(pgFormatStartCommandWaitForInput tools)
( \pgFmt -> do
Process.terminateProcess pgFmt.procHdl
-- make sure we don’t leave any zombies
_ <- forkIO $ do
_ <- Process.waitForProcess pgFmt.procHdl
pure ()
pure ()
)
-- unused resource time
100
-- number of resources
10
)
-- fill the pool with resources
let go =
Pool.tryWithResource pool (\_ -> go) >>= \case
Nothing -> pure ()
Just () -> pure ()
_ <- go
pure (PgFormatPool {pool, pgFormat = tools.pgFormat})
destroyPgFormatPool :: PgFormatPool -> IO ()
destroyPgFormatPool pool = Pool.destroyAllResources pool.pool
-- | Get the oldest resource from the pool, or stop if you find a resource that’s older than `cutoffPointMs`.
takeOldestResource :: PgFormatPool -> Arg "cutoffPointMs" Integer -> IO (PgFormatProcess, Pool.LocalPool PgFormatProcess)
takeOldestResource pool cutoffPointMs = do
now <- Otel.getTimestamp
mask_ $ do
a <- Pool.takeResource pool.pool
(putBack, res) <- go now [] a
-- make sure we don’t leak any resources we didn’t use in the end
for_ putBack $ \(x, xLocal) -> Pool.putResource xLocal x
pure res
where
mkMs ts = (ts & Otel.timestampNanoseconds & toInteger) `div` 1000_000
go now putBack a@(a', _) =
if abs (mkMs now - mkMs a'.startedAt) > cutoffPointMs.unArg
then pure (putBack, a)
else
Pool.tryTakeResource pool.pool >>= \case
Nothing -> pure (putBack, a)
Just b@(b', _) -> do
if a'.startedAt < b'.startedAt
then go now (b : putBack) a
else go now (a : putBack) b
-- | Format the given SQL with pg_formatter. Will use the pool of already running formatters to speed up execution.
runPgFormat :: PgFormatPool -> ByteString -> IO (T3 "exitCode" ExitCode "formatted" ByteString "stderr" ByteString)
runPgFormat pool sqlStatement = do
bracket
(takeOldestResource pool 200)
( \(a, localPool) -> do
-- we always destroy the resource, because the process exited
Pool.destroyResource pool.pool localPool a
-- create a new process to keep the pool “warm”
new <- pgFormatStartCommandWaitForInput pool
Pool.putResource localPool new
)
( \(pgFmt, _localPool) -> do
ByteString.hPut pgFmt.stdinHdl sqlStatement
-- close stdin to make pg_formatter format (it exits …)
-- issue: https://github.com/darold/pgFormatter/issues/333
hClose pgFmt.stdinHdl
formatted <- ByteString.hGetContents pgFmt.stdoutHdl
errs <- ByteString.hGetContents pgFmt.stderrHdl
exitCode <- Process.waitForProcess pgFmt.procHdl
pure $
T3
(label @"exitCode" exitCode)
(label @"formatted" formatted)
(label @"stderr" errs)
)
runPGTransactionImpl ::
(MonadUnliftIO m) =>
m (Pool Postgres.Connection) ->
Transaction m a ->
m a
{-# INLINE runPGTransactionImpl #-}
runPGTransactionImpl zoom (Transaction transaction) = do
pool <- zoom
withRunInIO $ \unliftIO ->
withPGTransaction pool $ \conn -> do
unliftIO $ runReaderT transaction conn
executeImpl ::
(ToRow params, MonadUnliftIO m, MonadLogger m, Otel.MonadTracer m) =>
m (DebugLogDatabaseQueries, PrettyPrintDatabaseQueries) ->
Query ->
params ->
Transaction m (Label "numberOfRowsAffected" Natural)
{-# INLINE executeImpl #-}
executeImpl zoomDbOptions qry params =
Otel.inSpan' "Postgres Query (execute)" Otel.defaultSpanArguments $ \span -> do
(logDatabaseQueries, prettyQuery) <- lift @Transaction zoomDbOptions
traceQueryIfEnabled span logDatabaseQueries prettyQuery qry (HasSingleParam params)
conn <- Transaction ask
PG.execute conn qry params
& handlePGException prettyQuery "execute" qry (Left params)
>>= toNumberOfRowsAffected "executeImpl"
executeImpl_ ::
( MonadUnliftIO m,
MonadLogger m,
Otel.MonadTracer m
) =>
m (DebugLogDatabaseQueries, PrettyPrintDatabaseQueries) ->
Query ->
Transaction m (Label "numberOfRowsAffected" Natural)
{-# INLINE executeImpl_ #-}
executeImpl_ zoomDbOptions qry =
Otel.inSpan' "Postgres Query (execute)" Otel.defaultSpanArguments $ \span -> do
(logDatabaseQueries, prettyQuery) <- lift @Transaction zoomDbOptions
traceQueryIfEnabled @() span logDatabaseQueries prettyQuery qry HasNoParams
conn <- Transaction ask
PG.execute_ conn qry
& handlePGException prettyQuery "execute_" qry (Left ())
>>= toNumberOfRowsAffected "executeImpl_"
executeManyImpl ::
(ToRow params, MonadUnliftIO m, MonadLogger m, Otel.MonadTracer m) =>
m (DebugLogDatabaseQueries, PrettyPrintDatabaseQueries) ->
Query ->
NonEmpty params ->
Transaction m (Label "numberOfRowsAffected" Natural)
executeManyImpl zoomDbOptions qry params =
Otel.inSpan' "Postgres Query (executeMany)" Otel.defaultSpanArguments $ \span -> do
(logDatabaseQueries, prettyQuery) <- lift @Transaction zoomDbOptions
traceQueryIfEnabled span logDatabaseQueries prettyQuery qry (HasMultiParams params)
conn <- Transaction ask
PG.executeMany conn qry (params & toList)
& handlePGException prettyQuery "executeMany" qry (Right params)
>>= toNumberOfRowsAffected "executeManyImpl"
toNumberOfRowsAffected :: (MonadIO m) => Text -> Int64 -> m (Label "numberOfRowsAffected" Natural)
toNumberOfRowsAffected functionName i64 =
i64
& intToNatural
& annotate [fmt|{functionName}: postgres returned a negative number of rows affected: {i64}|]
-- we throw this directly in IO here, because we don’t want to e.g. have to propagate MonadThrow through user code (it’s an assertion)
& unwrapIOError
& liftIO
<&> label @"numberOfRowsAffected"
executeManyReturningWithImpl ::
( ToRow params,
MonadUnliftIO m,
MonadLogger m,
Otel.MonadTracer m
) =>
m (DebugLogDatabaseQueries, PrettyPrintDatabaseQueries) ->
Query ->
NonEmpty params ->
Decoder r ->
Transaction m [r]
{-# INLINE executeManyReturningWithImpl #-}
executeManyReturningWithImpl zoomDbOptions qry params (Decoder fromRow) = do
Otel.inSpan' "Postgres Query (executeManyReturning)" Otel.defaultSpanArguments $ \span -> do
(logDatabaseQueries, prettyQuery) <- lift @Transaction zoomDbOptions
traceQueryIfEnabled span logDatabaseQueries prettyQuery qry (HasMultiParams params)
conn <- Transaction ask
PG.returningWith fromRow conn qry (params & toList)
& handlePGException prettyQuery "executeManyReturning" qry (Right params)
foldRowsWithAccImpl ::
( ToRow params,
MonadUnliftIO m,
MonadLogger m,
Otel.MonadTracer m
) =>
m (DebugLogDatabaseQueries, PrettyPrintDatabaseQueries) ->
Query ->
params ->
Decoder row ->
a ->
(a -> row -> Transaction m a) ->
Transaction m a
{-# INLINE foldRowsWithAccImpl #-}
foldRowsWithAccImpl zoomDbOptions qry params (Decoder rowParser) accumulator f = do
Otel.inSpan' "Postgres Query (foldRowsWithAcc)" Otel.defaultSpanArguments $ \span -> do
(logDatabaseQueries, prettyQuery) <- lift @Transaction zoomDbOptions
traceQueryIfEnabled span logDatabaseQueries prettyQuery qry (HasSingleParam params)
conn <- Transaction ask
withRunInIO
( \runInIO ->
do
PG.foldWithOptionsAndParser
PG.defaultFoldOptions
rowParser
conn
qry
params
accumulator
(\acc row -> runInIO $ f acc row)
& handlePGException prettyQuery "fold" qry (Left params)
& runInIO
)
pgFormatQueryNoParams' ::
(MonadIO m, MonadLogger m) =>
PrettyPrintDatabaseQueries ->
Query ->
Transaction m ByteString
pgFormatQueryNoParams' prettyQuery q = case prettyQuery of
DontPrettyPrintDatabaseQueries -> pure q.fromQuery
PrettyPrintDatabaseQueries pool -> lift $ pgFormatQueryByteString pool q.fromQuery
pgFormatQuery ::
(ToRow params, MonadIO m) =>
Query ->
params ->
Transaction m ByteString
pgFormatQuery qry params = Transaction $ do
conn <- ask
liftIO $ PG.formatQuery conn qry params
pgFormatQueryMany ::
(MonadIO m, ToRow params) =>
Query ->
NonEmpty params ->
Transaction m ByteString
pgFormatQueryMany qry params = Transaction $ do
conn <- ask
liftIO $
PG.formatMany
conn
qry
( params
-- upstream is partial on empty list, see https://github.com/haskellari/postgresql-simple/issues/129
& toList
)
queryWithImpl ::
( ToRow params,
MonadUnliftIO m,
MonadLogger m,
Otel.MonadTracer m
) =>
m (DebugLogDatabaseQueries, PrettyPrintDatabaseQueries) ->
Query ->
params ->
Decoder r ->
Transaction m [r]
{-# INLINE queryWithImpl #-}
queryWithImpl zoomDbOptions qry params (Decoder fromRow) = do
Otel.inSpan' "Postgres Query (queryWith)" Otel.defaultSpanArguments $ \span -> do
(logDatabaseQueries, prettyQuery) <- lift @Transaction zoomDbOptions
traceQueryIfEnabled span logDatabaseQueries prettyQuery qry (HasSingleParam params)
conn <- Transaction ask
PG.queryWith fromRow conn qry params
& handlePGException prettyQuery "query" qry (Left params)
queryWithImpl_ ::
( MonadUnliftIO m,
MonadLogger m
) =>
m PrettyPrintDatabaseQueries ->
Query ->
Decoder r ->
Transaction m [r]
{-# INLINE queryWithImpl_ #-}
queryWithImpl_ zoomDbOptions qry (Decoder fromRow) = do
prettyQuery <- lift @Transaction zoomDbOptions
conn <- Transaction ask
liftIO (PG.queryWith_ fromRow conn qry)
& handlePGException prettyQuery "query" qry (Left ())
data SingleRowError = SingleRowError
{ -- | How many columns were actually returned by the query
numberOfRowsReturned :: Int
}
deriving stock (Show)
instance Exception SingleRowError where
displayException (SingleRowError {..}) = [fmt|Single row expected from SQL query result, {numberOfRowsReturned} rows were returned instead."|]
pgFormatQuery' ::
( MonadIO m,
ToRow params,
MonadLogger m
) =>
PrettyPrintDatabaseQueries ->
Query ->
params ->
Transaction m ByteString
pgFormatQuery' prettyQuery q p = case prettyQuery of
DontPrettyPrintDatabaseQueries -> pgFormatQuery q p
PrettyPrintDatabaseQueries pool ->
pgFormatQuery q p
>>= lift . pgFormatQueryByteString pool
pgFormatQueryMany' ::
( MonadIO m,
ToRow params,
MonadLogger m
) =>
PrettyPrintDatabaseQueries ->
Query ->
NonEmpty params ->
Transaction m ByteString
pgFormatQueryMany' prettyQuery q p = case prettyQuery of
DontPrettyPrintDatabaseQueries -> pgFormatQueryMany q p
PrettyPrintDatabaseQueries pool ->
pgFormatQueryMany q p
>>= lift . pgFormatQueryByteString pool
-- | Read the executable name "pg_format"
postgresToolsParser :: ToolParserT IO (Label "pgFormat" Tool)
postgresToolsParser = label @"pgFormat" <$> readTool "pg_format"
pgFormatQueryByteString ::
( MonadIO m,
MonadLogger m
) =>
PgFormatPool ->
ByteString ->
m ByteString
pgFormatQueryByteString pool queryBytes = do
res <-
liftIO $
runPgFormat
pool
(queryBytes)
case res.exitCode of
ExitSuccess -> pure (res.formatted)
ExitFailure status -> do
logWarn [fmt|pg_format failed with status {status} while formatting the query, using original query string. Is there a syntax error?|]
logDebug
( prettyErrorTree
( nestedMultiError
"pg_format output"
( nestedError "stdout" (singleError (res.formatted & bytesToTextUtf8Lenient & newError))
:| [(nestedError "stderr" (singleError (res.stderr & bytesToTextUtf8Lenient & newError)))]
)
)
)
logDebug [fmt|pg_format stdout: stderr|]
pure (queryBytes)
pgFormatStartCommandWaitForInput ::
( MonadIO m,
HasField "pgFormat" tools Tool,
MonadFail m
) =>
tools ->
m PgFormatProcess
pgFormatStartCommandWaitForInput tools = do
do
startedAt <- Otel.getTimestamp
(Just stdinHdl, Just stdoutHdl, Just stderrHdl, procHdl) <-
Process.createProcess
( ( Process.proc
tools.pgFormat.toolPath
[ "--no-rcfile",
"-"
]
)
{ Process.std_in = Process.CreatePipe,
Process.std_out = Process.CreatePipe,
Process.std_err = Process.CreatePipe
}
)
pure PgFormatProcess {..}
data DebugLogDatabaseQueries
= -- | Do not log the database queries
DontLogDatabaseQueries
| -- | Log the database queries as debug output;
LogDatabaseQueries
| -- | Log the database queries as debug output and additionally the EXPLAIN output (from the query analyzer, not the actual values after execution cause that’s a bit harder to do)
LogDatabaseQueriesAndExplain
deriving stock (Show, Enum, Bounded)
-- | Whether to pipe database queries thru `pg_format` before logging them. This takes a long (long! 200ms+) time per query, so should only be used in debugging environments where speed is not an issue.
data PrettyPrintDatabaseQueries
= -- | Do not pretty-print database querios
DontPrettyPrintDatabaseQueries
| -- | Pretty-print database queries, slow
PrettyPrintDatabaseQueries PgFormatPool
instance Show PrettyPrintDatabaseQueries where
show DontPrettyPrintDatabaseQueries = "DontPrettyPrintDatabaseQueries"
show (PrettyPrintDatabaseQueries _) = "PrettyPrintDatabaseQueries"
data HasQueryParams param
= HasNoParams
| HasSingleParam param
| HasMultiParams (NonEmpty param)
-- | Log the postgres query depending on the given setting
traceQueryIfEnabled ::
( ToRow params,
MonadUnliftIO m,
MonadLogger m,
Otel.MonadTracer m
) =>
Otel.Span ->
DebugLogDatabaseQueries ->
PrettyPrintDatabaseQueries ->
Query ->
HasQueryParams params ->
Transaction m ()
traceQueryIfEnabled span logDatabaseQueries prettyQuery qry params = do
-- In case we have query logging enabled, we want to do that
let formattedQuery =
withEvent
span
"Query Format start"
"Query Format end"
$ case params of
HasNoParams -> pgFormatQueryNoParams' prettyQuery qry
HasSingleParam p -> pgFormatQuery' prettyQuery qry p
HasMultiParams ps -> pgFormatQueryMany' prettyQuery qry ps
let doLog errs = do
Otel.addAttribute span "_.postgres.query" (errs.query & bytesToTextUtf8Lenient & Otel.toAttribute)
for_ errs.explain $ \ex ->
Otel.addAttribute span "_.postgres.explain" (Otel.toAttribute @Text ex)
let doExplain = do
q <- formattedQuery
Otel.inSpan "Postgres EXPLAIN Query" Otel.defaultSpanArguments $ do
queryWithImpl_
(pure prettyQuery)
( "EXPLAIN "
<> (
-- TODO: this is not nice, but the only way to get the `executeMany` form to work with this
-- because we need the query with all elements already interpolated.
Query q
)
)
(Dec.fromField @Text)
<&> Text.intercalate "\n"
case logDatabaseQueries of
DontLogDatabaseQueries -> pure ()
LogDatabaseQueries -> do
q <- formattedQuery
doLog (T2 (label @"query" q) (label @"explain" Nothing))
LogDatabaseQueriesAndExplain -> do
q <- formattedQuery
-- XXX: stuff like `CREATE SCHEMA` cannot be EXPLAINed, so we should catch exceptions here
-- and just ignore anything that errors (if it errors because of a problem with the query, it would have been caught by the query itself.
ex <- doExplain
doLog (T2 (label @"query" q) (label @"explain" (Just ex)))
-- | Add a start and end event to the span, and figure out how long the difference was.
--
-- This is more lightweight than starting an extra span for timing things.
withEvent :: (MonadIO f) => Otel.Span -> Text -> Text -> f b -> f b
withEvent span start end act = do
let mkMs ts = (ts & Otel.timestampNanoseconds & toInteger) `div` 1000_000
s <- Otel.getTimestamp
Otel.addEvent
span
( Otel.NewEvent
{ newEventName = start,
newEventAttributes = mempty,
newEventTimestamp = Just s
}
)
res <- act
e <- Otel.getTimestamp
let tookMs =
(mkMs e - mkMs s)
-- should be small enough
& fromInteger @Int
Otel.addEvent
span
( Otel.NewEvent
{ newEventName = end,
newEventAttributes = HashMap.fromList [("took ms", Otel.toAttribute tookMs)],
newEventTimestamp = Just e
}
)
pure res
unzipPGArray ::
forall l1 t1 l2 t2 r.
( HasField l1 r t1,
HasField l2 r t2
) =>
[r] ->
(PGArray t1, PGArray t2)
{-# INLINEABLE unzipPGArray #-}
unzipPGArray xs =
( PGArray $ getField @l1 <$> xs,
PGArray $ getField @l2 <$> xs
)
unzip3PGArray ::
forall l1 t1 l2 t2 l3 t3 r.
( HasField l1 r t1,
HasField l2 r t2,
HasField l3 r t3
) =>
[r] ->
(PGArray t1, PGArray t2, PGArray t3)
{-# INLINEABLE unzip3PGArray #-}
unzip3PGArray xs =
( PGArray $ getField @l1 <$> xs,
PGArray $ getField @l2 <$> xs,
PGArray $ getField @l3 <$> xs
)
unzip4PGArray ::
forall l1 t1 l2 t2 l3 t3 l4 t4 r.
( HasField l1 r t1,
HasField l2 r t2,
HasField l3 r t3,
HasField l4 r t4
) =>
[r] ->
(PGArray t1, PGArray t2, PGArray t3, PGArray t4)
{-# INLINEABLE unzip4PGArray #-}
unzip4PGArray xs =
( PGArray $ getField @l1 <$> xs,
PGArray $ getField @l2 <$> xs,
PGArray $ getField @l3 <$> xs,
PGArray $ getField @l4 <$> xs
)
unzip5PGArray ::
forall l1 t1 l2 t2 l3 t3 l4 t4 l5 t5 r.
( HasField l1 r t1,
HasField l2 r t2,
HasField l3 r t3,
HasField l4 r t4,
HasField l5 r t5
) =>
[r] ->
(PGArray t1, PGArray t2, PGArray t3, PGArray t4, PGArray t5)
{-# INLINEABLE unzip5PGArray #-}
unzip5PGArray xs =
( PGArray $ getField @l1 <$> xs,
PGArray $ getField @l2 <$> xs,
PGArray $ getField @l3 <$> xs,
PGArray $ getField @l4 <$> xs,
PGArray $ getField @l5 <$> xs
)
instance (ToField t1) => ToRow (Label l1 t1) where
toRow t2 = toRow $ PG.Only $ getField @l1 t2
instance (ToField t1, ToField t2) => ToRow (T2 l1 t1 l2 t2) where
toRow t2 = toRow (getField @l1 t2, getField @l2 t2)
instance (ToField t1, ToField t2, ToField t3) => ToRow (T3 l1 t1 l2 t2 l3 t3) where
toRow t3 = toRow (getField @l1 t3, getField @l2 t3, getField @l3 t3)
|