13e8ea6 · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

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Merge pull request #147 from tstat/streaming

13e8ea6Leon P Smith11 years ago

src/Database/PostgreSQL/Simple.hs+84−14

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unifiedsplit

@@ -93,6 +93,14 @@ module Database.PostgreSQL.Simple

93 , forEach

94 , forEach_

95 , returning

96+ -- ** Queries that stream results taking a parser as an argument

97+ , foldWith

98+ , foldWithOptionsAndParser

99+ , foldWith_

100+ , foldWithOptionsAndParser_

101+ , forEachWith

102+ , forEachWith_

103+ , returningWith

96 -- * Statements that do not return results

104 -- * Statements that do not return results

97 , execute

105 , execute

98 , execute_

106 , execute_

@@ -349,10 +357,13 @@ executeMany conn q qs = do

349--

357--

350-- Throws 'FormatError' if the query could not be formatted correctly.

358-- Throws 'FormatError' if the query could not be formatted correctly.

351returning :: (ToRow q, FromRow r) => Connection -> Query -> [q] -> IO [r]

359returning :: (ToRow q, FromRow r) => Connection -> Query -> [q] -> IO [r]

360+returning = returningWith fromRow

361+

362+returningWith :: (ToRow q) => RowParser r -> Connection -> Query -> [q] -> IO [r]

352−returning _ _ [] = return []

363+returningWith _ _ _ [] = return []

353−returning conn q qs = do

364+returningWith parser conn q qs = do

354 result <- exec conn =<< formatMany conn q qs

365 result <- exec conn =<< formatMany conn q qs

355− finishQuery conn q result

366+ finishQueryWith parser conn q result

356

367

357-- | Perform a @SELECT@ or other SQL query that is expected to return

368-- | Perform a @SELECT@ or other SQL query that is expected to return

358-- results. All results are retrieved and converted before this

369-- results. All results are retrieved and converted before this

@@ -427,6 +438,17 @@ fold :: ( FromRow row, ToRow params )

427 -> IO a

438 -> IO a

428fold = foldWithOptions defaultFoldOptions

439fold = foldWithOptions defaultFoldOptions

429

440

441+-- | A version of 'fold' taking a parser as an argument

442+foldWith :: ( ToRow params )

443+ => RowParser row

444+ -> Connection

445+ -> Query

446+ -> params

447+ -> a

448+ -> (a -> row -> IO a)

449+ -> IO a

450+foldWith = foldWithOptionsAndParser defaultFoldOptions

451+

430-- | Number of rows to fetch at a time. 'Automatic' currently defaults

452-- | Number of rows to fetch at a time. 'Automatic' currently defaults

431-- to 256 rows, although it might be nice to make this more intelligent

453-- to 256 rows, although it might be nice to make this more intelligent

432-- based on e.g. the average size of the rows.

454-- based on e.g. the average size of the rows.

@@ -461,9 +483,21 @@ foldWithOptions :: ( FromRow row, ToRow params )

461 -> a

483 -> a

462 -> (a -> row -> IO a)

484 -> (a -> row -> IO a)

463 -> IO a

485 -> IO a

464−foldWithOptions opts conn template qs a f = do

486+foldWithOptions opts = foldWithOptionsAndParser opts fromRow

487+

488+-- | A version of 'foldWithOptions' taking a parser as an argument

489+foldWithOptionsAndParser :: (ToRow params)

490+ => FoldOptions

491+ -> RowParser row

492+ -> Connection

493+ -> Query

494+ -> params

495+ -> a

496+ -> (a -> row -> IO a)

497+ -> IO a

498+foldWithOptionsAndParser opts parser conn template qs a f = do

465 q <- formatQuery conn template qs

499 q <- formatQuery conn template qs

466− doFold opts conn template (Query q) a f

500+ doFold opts parser conn template (Query q) a f

467

501

468-- | A version of 'fold' that does not perform query substitution.

502-- | A version of 'fold' that does not perform query substitution.

469fold_ :: (FromRow r) =>

503fold_ :: (FromRow r) =>

@@ -474,6 +508,14 @@ fold_ :: (FromRow r) =>

474 -> IO a

508 -> IO a

475fold_ = foldWithOptions_ defaultFoldOptions

509fold_ = foldWithOptions_ defaultFoldOptions

476

510

511+-- | A version of 'foldWith' taking a parser as an argument

512+foldWith_ :: RowParser r

513+ -> Connection

514+ -> Query

515+ -> a

516+ -> (a -> r -> IO a)

517+ -> IO a

518+foldWith_ = foldWithOptionsAndParser_ defaultFoldOptions

477

519

478foldWithOptions_ :: (FromRow r) =>

520foldWithOptions_ :: (FromRow r) =>

479 FoldOptions

521 FoldOptions

@@ -482,18 +524,27 @@ foldWithOptions_ :: (FromRow r) =>

482 -> a -- ^ Initial state for result consumer.

524 -> a -- ^ Initial state for result consumer.

483 -> (a -> r -> IO a) -- ^ Result consumer.

525 -> (a -> r -> IO a) -- ^ Result consumer.

484 -> IO a

526 -> IO a

485−foldWithOptions_ opts conn query a f = doFold opts conn query query a f

527+foldWithOptions_ opts conn query a f = doFold opts fromRow conn query query a f

486−

528+

487−

529+-- | A version of 'foldWithOptions_' taking a parser as an argument

488−doFold :: ( FromRow row )

530+foldWithOptionsAndParser_ :: FoldOptions

489− => FoldOptions

531+ -> RowParser r

532+ -> Connection

533+ -> Query -- ^ Query.

534+ -> a -- ^ Initial state for result consumer.

535+ -> (a -> r -> IO a) -- ^ Result consumer.

536+ -> IO a

537+foldWithOptionsAndParser_ opts parser conn query a f = doFold opts parser conn query query a f

538+

539+doFold :: FoldOptions

540+ -> RowParser row

490 -> Connection

541 -> Connection

491 -> Query

542 -> Query

492 -> Query

543 -> Query

493 -> a

544 -> a

494 -> (a -> row -> IO a)

545 -> (a -> row -> IO a)

495 -> IO a

546 -> IO a

496−doFold FoldOptions{..} conn _template q a0 f = do

547+doFold FoldOptions{..} parser conn _template q a0 f = do

497 stat <- withConnection conn PQ.transactionStatus

548 stat <- withConnection conn PQ.transactionStatus

498 case stat of

549 case stat of

499 PQ.TransIdle -> withTransactionMode transactionMode conn go

550 PQ.TransIdle -> withTransactionMode transactionMode conn go

@@ -516,7 +567,7 @@ doFold FoldOptions{..} conn _template q a0 f = do

516 _ <- execute_ conn $ mconcat

567 _ <- execute_ conn $ mconcat

517 [ "DECLARE ", name, " NO SCROLL CURSOR FOR ", q ]

568 [ "DECLARE ", name, " NO SCROLL CURSOR FOR ", q ]

518 return name

569 return name

519− fetch (Query name) = query_ conn $

570+ fetch (Query name) = queryWith_ parser conn $

520 Query (toByteString (byteString "FETCH FORWARD "

571 Query (toByteString (byteString "FETCH FORWARD "

521 <> intDec chunkSize

572 <> intDec chunkSize

522 <> byteString " FROM "

573 <> byteString " FROM "

@@ -551,18 +602,37 @@ forEach :: (ToRow q, FromRow r) =>

551 -> q -- ^ Query parameters.

602 -> q -- ^ Query parameters.

552 -> (r -> IO ()) -- ^ Result consumer.

603 -> (r -> IO ()) -- ^ Result consumer.

553 -> IO ()

604 -> IO ()

554−forEach conn template qs = fold conn template qs () . const

605+forEach = forEachWith fromRow

555{-# INLINE forEach #-}

606{-# INLINE forEach #-}

556

607

608+-- | A version of 'forEach' taking a parser as an argument

609+forEachWith :: ( ToRow q )

610+ => RowParser r

611+ -> Connection

612+ -> Query

613+ -> q

614+ -> (r -> IO ())

615+ -> IO ()

616+forEachWith parser conn template qs = foldWith parser conn template qs () . const

617+{-# INLINE forEachWith #-}

618+

557-- | A version of 'forEach' that does not perform query substitution.

619-- | A version of 'forEach' that does not perform query substitution.

558forEach_ :: (FromRow r) =>

620forEach_ :: (FromRow r) =>

559 Connection

621 Connection

560 -> Query -- ^ Query template.

622 -> Query -- ^ Query template.

561 -> (r -> IO ()) -- ^ Result consumer.

623 -> (r -> IO ()) -- ^ Result consumer.

562 -> IO ()

624 -> IO ()

563−forEach_ conn template = fold_ conn template () . const

625+forEach_ = forEachWith_ fromRow

564{-# INLINE forEach_ #-}

626{-# INLINE forEach_ #-}

565

627

628+forEachWith_ :: RowParser r

629+ -> Connection

630+ -> Query

631+ -> (r -> IO ())

632+ -> IO ()

633+forEachWith_ parser conn template = foldWith_ parser conn template () . const

634+{-# INLINE forEachWith_ #-}

635+

566forM' :: (Ord n, Num n) => n -> n -> (n -> IO a) -> IO [a]

636forM' :: (Ord n, Num n) => n -> n -> (n -> IO a) -> IO [a]

567forM' lo hi m = loop hi []

637forM' lo hi m = loop hi []

568 where

638 where

src/Database/PostgreSQL/Simple/LargeObjects.hs+1−1

@@ -14,7 +14,7 @@

14-- database transaction, so if you are interested in using anything beyond

15-- 'loCreat', 'loCreate', and 'loUnlink', you will need to run the entire

16-- sequence of functions in a transaction. As 'loImport' and 'loExport'

17−-- are simply C functions that call 'loCreat', 'loOpen', 'loRead', and

17+-- are simply C functions that call 'loCreat', 'loOpen', 'loRead', and

18-- 'loWrite', and do not perform any transaction handling themselves,

19-- they also need to be wrapped in an explicit transaction.

20--