    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Database.PostgreSQL.LibPQ
    -- Copyright   :  (c) 2010 Grant Monroe,
    --                (c) 2011 Leon P Smith
    -- License     :  BSD3
    --
    -- Maintainer  :  leon@melding-monads.com
    -- Stability   :  experimental
    --
    -- This is a binding to libpq: the C application programmer's
    -- interface to PostgreSQL. libpq is a set of library functions that
    -- allow client programs to pass queries to the PostgreSQL backend
    -- server and to receive the results of these queries.
    --
    -- This is intended to be a very low-level interface to libpq.  It
    -- provides memory management and a somewhat more consistent interface
    -- to error conditions.  Application code should typically use a
    -- higher-level PostgreSQL binding.
    --
    -- This interface is not safe,  because libpq unfortunately conflates
    -- explicit disconnects with memory management.   A use-after-free memory
    -- fault will result if a connection is used in any way after 'finish' is
    -- called.  This will likely cause a segfault,  or return an error if memory
    -- has not yet been reused.  Other more bizarre behaviors are possible,
    -- though unlikely by chance.  Higher-level bindings need to be aware of
    -- this issue and need to ensure that application code cannot cause the
    -- functions in this module to be called on an 'finish'ed connection.
    --
    -- One possibility is to represent a connection in a higher-level interface
    -- as @MVar (Maybe Connection)@, using @Nothing@ to represent an explicitly
    -- disconnected state.  This was done in an earlier incarnation of this
    -- library,  however this was removed because a higher level binding is
    -- likely to use a similar construct to deal with other issues.  Thus
    -- incorporating that in this module results in extra layers of indirection
    -- for relatively little functionality.
    --
    -----------------------------------------------------------------------------

    {-# LANGUAGE BangPatterns               #-}
    {-# LANGUAGE DerivingStrategies         #-}
    {-# LANGUAGE GeneralizedNewtypeDeriving #-}
    {-# LANGUAGE OverloadedStrings          #-}
    {-# LANGUAGE ScopedTypeVariables        #-}

    -- The FFI imports are in .FFI module
    {-# LANGUAGE NoForeignFunctionInterface #-}

    module Database.PostgreSQL.LibPQ
        (
        -- * Database Connection Control Functions
        -- $dbconn
          Connection
        , connectdb
        , connectStart
        , connectPoll
        , newNullConnection
        , isNullConnection
        --, conndefaults
        --, conninfoParse
        , reset
        , resetStart
        , resetPoll
        , PollingStatus(..)
        , finish

        -- * Connection Status Functions
        -- $connstatus
        , db
        , user
        , pass
        , host
        , port
        , options
        , ConnStatus(..)
        , status
        , TransactionStatus(..)
        , transactionStatus
        , parameterStatus
        , protocolVersion
        , serverVersion
        , libpqVersion
        , errorMessage
        , socket
        , backendPID
        , connectionNeedsPassword
        , connectionUsedPassword
        --, getssl

        -- * Command Execution Functions
        -- $commandexec
        , Result
        , exec
        , Format(..)
        , Oid(..)
        , invalidOid
        , execParams
        , prepare
        , execPrepared
        , describePrepared
        , describePortal
        , ExecStatus(..)
        , resultStatus
        , resStatus
        , resultErrorMessage
        , FieldCode(..)
        , resultErrorField
        , unsafeFreeResult

        -- * Retrieving Query Result Information
        -- $queryresultinfo
        , ntuples
        , nfields
        , Row(..)
        , Column(..)
        , toRow
        , toColumn
        , fname
        , fnumber
        , ftable
        , ftablecol
        , fformat
        , ftype
        , fmod
        , fsize
        , getvalue
        , getvalue'
        , getisnull
        , getlength
        , nparams
        , paramtype

        -- Retrieving Result Information for Other Commands
        -- $othercommands
        , cmdStatus
        , cmdTuples

        -- * Escaping Strings for Inclusion in SQL Commands
        , escapeStringConn

        -- * Escaping Binary Strings for Inclusion in SQL Commands
        , escapeByteaConn
        , unescapeBytea

        -- * Escaping Identifiers for Inclusion in SQL Commands
        , escapeIdentifier

        -- * Using COPY
        -- $copy
        , CopyInResult(..)
        , putCopyData
        , putCopyEnd
        , CopyOutResult(..)
        , getCopyData

        -- * Asynchronous Command Processing
        -- $asynccommand
        , sendQuery
        , sendQueryParams
        , sendPrepare
        , sendQueryPrepared
        , sendDescribePrepared
        , sendDescribePortal
        , getResult
        , consumeInput
        , isBusy
        , setnonblocking
        , isnonblocking
        , setSingleRowMode
        , FlushStatus(..)
        , flush

        -- * Pipeline Mode
        -- $pipelinemode
        , PipelineStatus(..)
        , pipelineStatus
        , enterPipelineMode
        , exitPipelineMode
        , pipelineSync
        , sendFlushRequest

        -- * Cancelling Queries in Progress
        -- $cancel
        , Cancel
        , getCancel
        , cancel

        -- * Asynchronous Notification
        -- $asyncnotification
        , Notify(..)
        , notifies

        -- * Control Functions
        -- $control
        , clientEncoding
        , setClientEncoding
        , Verbosity(..)
        , setErrorVerbosity

        -- * Nonfatal Error Reporting
        , disableNoticeReporting
        , enableNoticeReporting
        , getNotice

        -- * Large Objects
        -- $largeobjects
        , LoFd(..)
        , loCreat
        , loCreate
        , loImport
        , loImportWithOid
        , loExport
        , loOpen
        , loWrite
        , loRead
        , loSeek
        , loTell
        , loTruncate
        , loClose
        , loUnlink
        )
    where

    import Control.Concurrent.MVar (MVar, newMVar, swapMVar, tryTakeMVar, withMVar)
    import Control.Exception       (mask_)
    import Foreign.C.String        (CString, CStringLen, withCString)
    import Foreign.C.Types         (CInt (..))
    import Foreign.ForeignPtr      (ForeignPtr, finalizeForeignPtr, newForeignPtr, newForeignPtr_, touchForeignPtr, withForeignPtr)
    import Foreign.Marshal         (alloca, allocaBytes, finalizerFree, free, mallocBytes, maybeWith, reallocBytes, withArrayLen, withMany)
    import Foreign.Ptr             (Ptr, castPtr, nullPtr)
    import Foreign.Storable        (Storable (peek))
    import GHC.Conc                (closeFdWith)
    import System.IO               (IOMode (..), SeekMode (..))
    import System.Posix.Types      (CPid, Fd (..))

    import qualified Data.ByteString           as B
    import qualified Data.ByteString.Internal  as B (c_strlen, createAndTrim, fromForeignPtr)
    import qualified Data.ByteString.Unsafe    as B
    import qualified Foreign.Concurrent        as FC
    import qualified Foreign.ForeignPtr.Unsafe as Unsafe

    import Database.PostgreSQL.LibPQ.Compat
    import Database.PostgreSQL.LibPQ.Enums
    import Database.PostgreSQL.LibPQ.FFI
    import Database.PostgreSQL.LibPQ.Internal
    import Database.PostgreSQL.LibPQ.Marshal
    import Database.PostgreSQL.LibPQ.Notify
    import Database.PostgreSQL.LibPQ.Oid
    import Database.PostgreSQL.LibPQ.Ptr

    -- $dbconn
    -- The following functions deal with making a connection to a
    -- PostgreSQL backend server. An application program can have several
    -- backend connections open at one time. (One reason to do that is to
    -- access more than one database.) Each connection is represented by a
    -- 'Connection', which is obtained from the function 'connectdb', or
    -- 'connectStart'. The 'status' function should be called to check
    -- whether a connection was successfully made before queries are sent
    -- via the connection object.

    -- | Makes a new connection to the database server.
    --
    -- This function opens a new database connection using the parameters
    --  taken from the string conninfo. Its nonblocking analogues are
    --  'connectStart' and 'connectPoll'.
    --
    -- The passed string can be empty to use all default parameters, or it
    -- can contain one or more parameter settings separated by
    -- whitespace. Each parameter setting is in the form keyword =
    -- value. Spaces around the equal sign are optional. To write an empty
    -- value or a value containing spaces, surround it with single quotes,
    -- e.g., keyword = 'a value'. Single quotes and backslashes within the
    -- value must be escaped with a backslash, i.e., \' and \\.
    connectdb :: B.ByteString -- ^ Connection Info
              -> IO Connection
    connectdb :: ByteString -> IO Connection
    connectdb ByteString
    conninfo =
        IO Connection -> IO Connection
    forall a. IO a -> IO a
    mask_ (IO Connection -> IO Connection) -> IO Connection -> IO Connection
    forall a b. (a -> b) -> a -> b
    $ do
           connPtr <- ByteString -> (CString -> IO (Ptr PGconn)) -> IO (Ptr PGconn)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    conninfo CString -> IO (Ptr PGconn)
    c_PQconnectdb
           if connPtr == nullPtr
               then fail "libpq failed to allocate a PGconn structure"
               else do
                 noticeBuffer <- newMVar nullPtr
                 connection <- newForeignPtrOnce connPtr (pqfinish connPtr noticeBuffer)
                 return $! Conn connection noticeBuffer

    -- | Make a connection to the database server in a nonblocking manner.
    connectStart :: B.ByteString -- ^ Connection Info
                 -> IO Connection
    connectStart :: ByteString -> IO Connection
    connectStart ByteString
    connStr =
        IO Connection -> IO Connection
    forall a. IO a -> IO a
    mask_ (IO Connection -> IO Connection) -> IO Connection -> IO Connection
    forall a b. (a -> b) -> a -> b
    $ do
           connPtr <- ByteString -> (CString -> IO (Ptr PGconn)) -> IO (Ptr PGconn)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    connStr CString -> IO (Ptr PGconn)
    c_PQconnectStart
           if connPtr == nullPtr
               then fail "libpq failed to allocate a PGconn structure"
               else do
                 noticeBuffer <- newMVar nullPtr
                 connection <- newForeignPtrOnce connPtr (pqfinish connPtr noticeBuffer)
                 return $! Conn connection noticeBuffer

    pqfinish :: Ptr PGconn -> MVar NoticeBuffer -> IO ()
    pqfinish :: Ptr PGconn -> MVar (Ptr CNoticeBuffer) -> IO ()
    pqfinish Ptr PGconn
    conn MVar (Ptr CNoticeBuffer)
    noticeBuffer = do
    --   This covers the case when a connection is closed while other Haskell
    --   threads are using GHC's IO manager to wait on the descriptor.  This is
    --   commonly the case with asynchronous notifications, for example.  Since
    --   libpq is responsible for opening and closing the file descriptor, GHC's
    --   IO manager needs to be informed that the file descriptor has been
    --   closed.  The IO manager will then raise an exception in those threads.
       mfd <- Ptr PGconn -> IO CInt
    c_PQsocket Ptr PGconn
    conn
       case mfd of
         -1 -> -- This can happen if the connection is bad/lost
               -- This case may be worth investigating further
               Ptr PGconn -> IO ()
    c_PQfinish Ptr PGconn
    conn
         CInt
    fd -> (Fd -> IO ()) -> Fd -> IO ()
    closeFdWith (\Fd
    _ -> Ptr PGconn -> IO ()
    c_PQfinish Ptr PGconn
    conn) (CInt -> Fd
    Fd CInt
    fd)

       nb <- swapMVar noticeBuffer nullPtr
       c_free_noticebuffer nb

    -- | Workaround for bug in 'FC.newForeignPtr' before base 4.6.  Ensure the
    -- finalizer is only run once, to prevent a segfault.  See GHC ticket #7170
    --
    -- Note that 'getvalue' and 'maybeBsFromForeignPtr' do not need this
    -- workaround, since their finalizers are just 'touchForeignPtr' calls.
    newForeignPtrOnce :: Ptr a -> IO () -> IO (ForeignPtr a)
    newForeignPtrOnce :: forall a. Ptr a -> IO () -> IO (ForeignPtr a)
    newForeignPtrOnce Ptr a
    ptr IO ()
    fin = do
        mv <- IO () -> IO (MVar (IO ()))
    forall a. a -> IO (MVar a)
    newMVar IO ()
    fin
        FC.newForeignPtr ptr $ tryTakeMVar mv >>= maybe (return ()) id

    -- | Allocate a Null Connection,  which all libpq functions
    -- should safely fail on.
    newNullConnection :: IO Connection
    newNullConnection :: IO Connection
    newNullConnection = do
      connection   <- Ptr PGconn -> IO (ForeignPtr PGconn)
    forall a. Ptr a -> IO (ForeignPtr a)
    newForeignPtr_ Ptr PGconn
    forall a. Ptr a
    nullPtr
      noticeBuffer <- newMVar nullPtr
      return $! Conn connection noticeBuffer

    -- | Test if a connection is the Null Connection.
    isNullConnection :: Connection -> Bool
    isNullConnection :: Connection -> Bool
    isNullConnection (Conn ForeignPtr PGconn
    x MVar (Ptr CNoticeBuffer)
    _) = ForeignPtr PGconn -> Ptr PGconn
    forall a. ForeignPtr a -> Ptr a
    Unsafe.unsafeForeignPtrToPtr ForeignPtr PGconn
    x Ptr PGconn -> Ptr PGconn -> Bool
    forall a. Eq a => a -> a -> Bool
    == Ptr PGconn
    forall a. Ptr a
    nullPtr
    {-# INLINE isNullConnection #-}

    -- | If 'connectStart' succeeds, the next stage is to poll libpq so
    -- that it can proceed with the connection sequence. Use 'socket' to
    -- obtain the 'Fd' of the socket underlying the database
    -- connection. Loop thus: If 'connectPoll' last returned
    -- 'PollingReading', wait until the socket is ready to read (as
    -- indicated by select(), poll(), or similar system function). Then
    -- call 'connectPoll' again. Conversely, if 'connectPoll' last
    -- returned 'PollingWriting', wait until the socket is ready to write,
    -- then call 'connectPoll' again. If you have yet to call
    -- 'connectPoll', i.e., just after the call to 'connectStart', behave
    -- as if it last returned 'PollingWriting'. Continue this loop until
    -- 'connectPoll' returns 'PollingFailed', indicating the connection
    -- procedure has failed, or 'PollingOk', indicating the connection has
    -- been successfully made.
    connectPoll :: Connection
                -> IO PollingStatus
    connectPoll :: Connection -> IO PollingStatus
    connectPoll = (Ptr PGconn -> IO CInt) -> Connection -> IO PollingStatus
    pollHelper Ptr PGconn -> IO CInt
    c_PQconnectPoll

    -- PQconndefaults
    -- Returns the default connection options.

    -- PQconninfoOption *PQconndefaults(void);

    -- typedef struct
    -- {
    --     char   *keyword;   /* The keyword of the option */
    --     char   *envvar;    /* Fallback environment variable name */
    --     char   *compiled;  /* Fallback compiled in default value */
    --     char   *val;       /* Option's current value, or NULL */
    --     char   *label;     /* Label for field in connect dialog */
    --     char   *dispchar;  /* Indicates how to display this field
    --                           in a connect dialog. Values are:
    --                           ""        Display entered value as is
    --                           "*"       Password field - hide value
    --                           "D"       Debug option - don't show by default */
    --     int     dispsize;  /* Field size in characters for dialog */
    -- } PQconninfoOption;
    -- Returns a connection options array. This can be used to determine all possible PQconnectdb options and their current default values. The return value points to an array of PQconninfoOption structures, which ends with an entry having a null keyword pointer. The null pointer is returned if memory could not be allocated. Note that the current default values (val fields) will depend on environment variables and other context. Callers must treat the connection options data as read-only.

    -- After processing the options array, free it by passing it to PQconninfoFree. If this is not done, a small amount of memory is leaked for each call to PQconndefaults.

    -- PQconninfoParse
    -- Returns parsed connection options from the provided connection string.

    -- PQconninfoOption *PQconninfoParse(const char *conninfo, char **errmsg);
    -- Parses a connection string and returns the resulting options as an array; or returns NULL if there is a problem with the connection string. This can be used to determine the PQconnectdb options in the provided connection string. The return value points to an array of PQconninfoOption structures, which ends with an entry having a null keyword pointer.

    -- Note that only options explicitly specified in the string will have values set in the result array; no defaults are inserted.

    -- If errmsg is not NULL, then *errmsg is set to NULL on success, else to a malloc'd error string explaining the problem. (It is also possible for *errmsg to be set to NULL even when NULL is returned; this indicates an out-of-memory situation.)

    -- After processing the options array, free it by passing it to PQconninfoFree. If this is not done, some memory is leaked for each call to PQconninfoParse. Conversely, if an error occurs and errmsg is not NULL, be sure to free the error string using PQfreemem.

    -- | Resets the communication channel to the server.
    --
    -- This function will close the connection to the server and attempt
    -- to reestablish a new connection to the same server, using all the
    -- same parameters previously used. This might be useful for error
    -- recovery if a working connection is lost.
    reset :: Connection
          -> IO ()
    reset :: Connection -> IO ()
    reset Connection
    connection = Connection -> (Ptr PGconn -> IO ()) -> IO ()
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO ()
    c_PQreset

    -- | Reset the communication channel to the server, in a nonblocking manner.
    resetStart :: Connection
               -> IO Bool
    resetStart :: Connection -> IO Bool
    resetStart Connection
    connection =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQresetStart

    -- | To initiate a connection reset, call 'resetStart'. If it returns
    -- 'False', the reset has failed. If it returns 'True', poll the reset
    -- using 'resetPoll' in exactly the same way as you would create the
    -- connection using 'connectPoll'.
    resetPoll :: Connection
              -> IO PollingStatus
    resetPoll :: Connection -> IO PollingStatus
    resetPoll = (Ptr PGconn -> IO CInt) -> Connection -> IO PollingStatus
    pollHelper Ptr PGconn -> IO CInt
    c_PQresetPoll

    pollHelper :: (Ptr PGconn -> IO CInt)
               -> Connection
               -> IO PollingStatus
    pollHelper :: (Ptr PGconn -> IO CInt) -> Connection -> IO PollingStatus
    pollHelper Ptr PGconn -> IO CInt
    poller Connection
    connection =
        do code <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    poller
           maybe
             (fail $ "unexpected polling status " ++ show code)
             return
             (fromCInt code)

    -- | Closes the connection to the server.
    --
    -- Note that the 'Connection' must not be used again after 'finish'
    -- has been called.
    finish :: Connection
           -> IO ()
    finish :: Connection -> IO ()
    finish (Conn ForeignPtr PGconn
    fp MVar (Ptr CNoticeBuffer)
    _) =
        do ForeignPtr PGconn -> IO ()
    forall a. ForeignPtr a -> IO ()
    finalizeForeignPtr ForeignPtr PGconn
    fp

    -- $connstatus
    -- These functions can be used to interrogate the status of an
    -- existing database connection object.

    -- | Returns the database name of the connection.
    db :: Connection
       -> IO (Maybe B.ByteString)
    db :: Connection -> IO (Maybe ByteString)
    db = (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    c_PQdb

    -- | Returns the user name of the connection.
    user :: Connection
         -> IO (Maybe B.ByteString)
    user :: Connection -> IO (Maybe ByteString)
    user = (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    c_PQuser

    -- | Returns the password of the connection.
    pass :: Connection
         -> IO (Maybe B.ByteString)
    pass :: Connection -> IO (Maybe ByteString)
    pass = (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    c_PQpass

    -- | Returns the server host name of the connection.
    host :: Connection
         -> IO (Maybe B.ByteString)
    host :: Connection -> IO (Maybe ByteString)
    host = (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    c_PQhost

    -- | Returns the port of the connection.
    port :: Connection
         -> IO (Maybe B.ByteString)
    port :: Connection -> IO (Maybe ByteString)
    port = (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    c_PQport

    -- | Returns the command-line options passed in the connection request.
    options :: Connection
            -> IO (Maybe B.ByteString)
    options :: Connection -> IO (Maybe ByteString)
    options = (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    c_PQoptions

    -- | Helper function that checks for nullPtrs and returns the empty
    -- string.
    statusString :: (Ptr PGconn -> IO CString)
                 -> Connection
                 -> IO (Maybe B.ByteString)
    statusString :: (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    f Connection
    connection =
        Connection
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    ptr ->
            do cstr <- Ptr PGconn -> IO CString
    f Ptr PGconn
    ptr
               if cstr == nullPtr
                 then return Nothing
                 else Just `fmap` B.packCString cstr

    -- | Returns the status of the connection.
    --
    -- The status can be one of a number of values. However, only two of
    -- these are seen outside of an asynchronous connection procedure:
    -- 'ConnectionOk' and 'ConnectionBad'. A good connection to the
    -- database has the status 'ConnectionOk'. A failed connection attempt
    -- is signaled by status 'ConnectionBad'. Ordinarily, an OK status
    -- will remain so until 'finish', but a communications failure might
    -- result in the status changing to 'ConnectionBad' prematurely. In
    -- that case the application could try to recover by calling 'reset'.
    --
    -- See the entry for 'connectStart' and 'connectPoll' with regards to
    -- other status codes that might be seen.
    status :: Connection
           -> IO ConnStatus
    status :: Connection -> IO ConnStatus
    status Connection
    connection = do
      stat <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQstatus
      maybe
        (fail $ "Unknown connection status " ++ show stat)
        return
        (fromCInt stat)

    -- | Returns the current in-transaction status of the server.
    --
    -- 'TransActive' is reported only when a query has been sent to the
    -- server and not yet completed.
    transactionStatus :: Connection
                      -> IO TransactionStatus
    transactionStatus :: Connection -> IO TransactionStatus
    transactionStatus Connection
    connection = do
      stat <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQtransactionStatus
      maybe
        (fail $ "Unknown transaction status " ++ show stat)
        return
        (fromCInt stat)

    -- | Looks up a current parameter setting of the server.
    --
    -- Certain parameter values are reported by the server automatically
    -- at connection startup or whenever their values
    -- change. 'parameterStatus' can be used to interrogate these
    -- settings. It returns the current value of a parameter if known, or
    -- 'Nothing' if the parameter is not known.
    parameterStatus :: Connection
                    -> B.ByteString -- ^ paramName
                    -> IO (Maybe B.ByteString)
    parameterStatus :: Connection -> ByteString -> IO (Maybe ByteString)
    parameterStatus Connection
    connection ByteString
    paramName =
        Connection
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    connPtr ->
            ByteString
    -> (CString -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    paramName ((CString -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (CString -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \CString
    paramNamePtr ->
            do cstr <- Ptr PGconn -> CString -> IO CString
    c_PQparameterStatus Ptr PGconn
    connPtr CString
    paramNamePtr
               if cstr == nullPtr
                 then return Nothing
                 else Just `fmap` B.packCString cstr

    -- | Interrogates the frontend/backend protocol being used.
    --
    -- Applications might wish to use this to determine whether certain
    -- features are supported. Currently, the possible values are 2 (2.0
    -- protocol), 3 (3.0 protocol), or zero (connection bad). This will
    -- not change after connection startup is complete, but it could
    -- theoretically change during a connection reset. The 3.0 protocol
    -- will normally be used when communicating with PostgreSQL 7.4 or
    -- later servers; pre-7.4 servers support only protocol 2.0. (Protocol
    -- 1.0 is obsolete and not supported by libpq.)
    protocolVersion :: Connection
                    -> IO Int
    protocolVersion :: Connection -> IO Int
    protocolVersion Connection
    connection =
        (CInt -> Int) -> IO CInt -> IO Int
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap CInt -> Int
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (IO CInt -> IO Int) -> IO CInt -> IO Int
    forall a b. (a -> b) -> a -> b
    $ Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQprotocolVersion

    -- | Returns an integer representing the backend version.
    --
    -- Applications might use this to determine the version of the
    -- database server they are connected to. The number is formed by
    -- converting the major, minor, and revision numbers into
    -- two-decimal-digit numbers and appending them together. For example,
    -- version 8.1.5 will be returned as 80105, and version 8.2 will be
    -- returned as 80200 (leading zeroes are not shown). Zero is returned
    -- if the connection is bad.
    serverVersion :: Connection
                  -> IO Int
    serverVersion :: Connection -> IO Int
    serverVersion Connection
    connection =
        (CInt -> Int) -> IO CInt -> IO Int
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap CInt -> Int
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (IO CInt -> IO Int) -> IO CInt -> IO Int
    forall a b. (a -> b) -> a -> b
    $ Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQserverVersion

    -- | Return the version of libpq that is being used.
    --
    -- The result of this function can be used to determine, at
    -- run time, if specific functionality is available in the currently
    -- loaded version of libpq. The function can be used, for example,
    -- to determine which connection options are available for
    -- PQconnectdb or if the hex bytea output added in PostgreSQL 9.0 is supported.
    --
    libpqVersion :: IO Int
    libpqVersion :: IO Int
    libpqVersion = (CInt -> Int) -> IO CInt -> IO Int
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap CInt -> Int
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral IO CInt
    c_PQlibVersion

    -- | Returns the error message most recently generated by an operation
    -- on the connection.
    --
    -- Nearly all libpq functions will set a message for 'errorMessage' if
    -- they fail. Note that by libpq convention, a nonempty 'errorMessage'
    -- result can be multiple lines, and will include a trailing
    -- newline. The result string should not be expected to remain the
    -- same across operations on the 'Connection'.
    errorMessage :: Connection
                 -> IO (Maybe B.ByteString)
    errorMessage :: Connection -> IO (Maybe ByteString)
    errorMessage = (Ptr PGconn -> IO CString) -> Connection -> IO (Maybe ByteString)
    statusString Ptr PGconn -> IO CString
    c_PQerrorMessage

    -- | Obtains the file descriptor number of the connection socket to
    -- the server. (This will not change during normal operation, but
    -- could change during connection setup or reset.)
    socket :: Connection
           -> IO (Maybe Fd)
    socket :: Connection -> IO (Maybe Fd)
    socket Connection
    connection =
        do cFd <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQsocket
           case cFd of
             -1 -> Maybe Fd -> IO (Maybe Fd)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe Fd
    forall a. Maybe a
    Nothing
             CInt
    _  -> Maybe Fd -> IO (Maybe Fd)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Maybe Fd -> IO (Maybe Fd)) -> Maybe Fd -> IO (Maybe Fd)
    forall a b. (a -> b) -> a -> b
    $ Fd -> Maybe Fd
    forall a. a -> Maybe a
    Just (Fd -> Maybe Fd) -> Fd -> Maybe Fd
    forall a b. (a -> b) -> a -> b
    $ CInt -> Fd
    Fd CInt
    cFd

    -- | Returns the process 'CPid' of the backend server process
    -- handling this connection.
    --
    -- The backend PID is useful for debugging purposes and for comparison
    -- to NOTIFY messages (which include the PID of the notifying backend
    -- process). Note that the PID belongs to a process executing on the
    -- database server host, not the local host!
    backendPID :: Connection
               -> IO CPid
    backendPID :: Connection -> IO CPid
    backendPID Connection
    connection =
        (CInt -> CPid) -> IO CInt -> IO CPid
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap CInt -> CPid
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (IO CInt -> IO CPid) -> IO CInt -> IO CPid
    forall a b. (a -> b) -> a -> b
    $ Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQbackendPID

    -- | Returns 'True' if the connection authentication method required a
    -- password, but none was available. Returns 'False' if not.
    --
    -- This function can be applied after a failed connection attempt to
    -- decide whether to prompt the user for a password.
    connectionNeedsPassword :: Connection
                            -> IO Bool
    connectionNeedsPassword :: Connection -> IO Bool
    connectionNeedsPassword Connection
    connection =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQconnectionNeedsPassword

    -- | Returns 'True' if the connection authentication method used a
    -- password. Returns 'False' if not.
    --
    -- This function can be applied after either a failed or successful
    -- connection attempt to detect whether the server demanded a
    -- password.
    connectionUsedPassword :: Connection
                           -> IO Bool
    connectionUsedPassword :: Connection -> IO Bool
    connectionUsedPassword Connection
    connection =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQconnectionUsedPassword

    -- TODO: getSSL :: Connection -> IO SSL

    -- $commandexec
    -- Once a connection to a database server has been successfully
    -- established, the functions described here are used to perform SQL
    -- queries and commands.

    -- | 'Result' encapsulates the result of a query (or more precisely,
    -- of a single SQL command --- a query string given to 'sendQuery' can
    -- contain multiple commands and thus return multiple instances of
    -- 'Result'.
    newtype Result = Result (ForeignPtr PGresult) deriving (Result -> Result -> Bool
    (Result -> Result -> Bool)
    -> (Result -> Result -> Bool) -> Eq Result
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: Result -> Result -> Bool
    == :: Result -> Result -> Bool
    $c/= :: Result -> Result -> Bool
    /= :: Result -> Result -> Bool
    Eq, Int -> Result -> [Char] -> [Char]
    [Result] -> [Char] -> [Char]
    Result -> [Char]
    (Int -> Result -> [Char] -> [Char])
    -> (Result -> [Char])
    -> ([Result] -> [Char] -> [Char])
    -> Show Result
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> Result -> [Char] -> [Char]
    showsPrec :: Int -> Result -> [Char] -> [Char]
    $cshow :: Result -> [Char]
    show :: Result -> [Char]
    $cshowList :: [Result] -> [Char] -> [Char]
    showList :: [Result] -> [Char] -> [Char]
    Show)

    -- | Prepare the given parameter bytestring for passing on to libpq,
    -- without copying for binary parameters.
    --
    -- This is safe to use to pass parameters to libpq considering:
    -- * libpq treats the parameter data as read-only
    -- * 'ByteString' uses pinned memory
    -- * the reference to the 'CString' doesn't escape
    unsafeUseParamAsCString :: (B.ByteString, Format) -> (CString -> IO a) -> IO a
    unsafeUseParamAsCString :: forall a. (ByteString, Format) -> (CString -> IO a) -> IO a
    unsafeUseParamAsCString (ByteString
    bs, Format
    format) CString -> IO a
    kont =
        case Format
    format of
            Format
    Binary -> ByteString -> (CStringLen -> IO a) -> IO a
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
    B.unsafeUseAsCStringLen ByteString
    bs CStringLen -> IO a
    forall {a}. (Eq a, Num a) => (CString, a) -> IO a
    kont'
            Format
    Text   -> ByteString -> (CString -> IO a) -> IO a
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    bs CString -> IO a
    kont
      where
        kont' :: (CString, a) -> IO a
    kont' (CString
    ptr, a
    0) = if CString
    ptr CString -> CString -> Bool
    forall a. Eq a => a -> a -> Bool
    == CString
    forall a. Ptr a
    nullPtr then CString -> IO a
    kont CString
    forall a. Ptr a
    emptyPtr else CString -> IO a
    kont CString
    ptr
        kont' (CString
    ptr, a
    _) = CString -> IO a
    kont CString
    ptr

    -- | Convert a list of parameters to the format expected by libpq FFI calls.
    withParams :: [Maybe (Oid, B.ByteString, Format)]
               -> (CInt -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a)
               -> IO a
    withParams :: forall a.
    [Maybe (Oid, ByteString, Format)]
    -> (CInt -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a)
    -> IO a
    withParams [Maybe (Oid, ByteString, Format)]
    params CInt -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a
    action =
        Int -> [Oid] -> (Ptr Oid -> IO a) -> IO a
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
    unsafeWithArray Int
    n [Oid]
    oids ((Ptr Oid -> IO a) -> IO a) -> (Ptr Oid -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Ptr Oid
    ts ->
            (Maybe (ByteString, Format) -> (CString -> IO a) -> IO a)
    -> [Maybe (ByteString, Format)] -> ([CString] -> IO a) -> IO a
    forall a b res.
    (a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res
    withMany (((ByteString, Format) -> (CString -> IO a) -> IO a)
    -> Maybe (ByteString, Format) -> (CString -> IO a) -> IO a
    forall a b c.
    (a -> (Ptr b -> IO c) -> IO c)
    -> Maybe a -> (Ptr b -> IO c) -> IO c
    maybeWith (ByteString, Format) -> (CString -> IO a) -> IO a
    forall a. (ByteString, Format) -> (CString -> IO a) -> IO a
    unsafeUseParamAsCString) [Maybe (ByteString, Format)]
    values (([CString] -> IO a) -> IO a) -> ([CString] -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \[CString]
    c_values ->
                Int -> [CString] -> (Ptr CString -> IO a) -> IO a
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
    unsafeWithArray Int
    n [CString]
    c_values ((Ptr CString -> IO a) -> IO a) -> (Ptr CString -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Ptr CString
    vs ->
                    Int -> [CInt] -> (Ptr CInt -> IO a) -> IO a
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
    unsafeWithArray Int
    n [CInt]
    c_lengths ((Ptr CInt -> IO a) -> IO a) -> (Ptr CInt -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Ptr CInt
    ls ->
                        Int -> [CInt] -> (Ptr CInt -> IO a) -> IO a
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
    unsafeWithArray Int
    n [CInt]
    formats ((Ptr CInt -> IO a) -> IO a) -> (Ptr CInt -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Ptr CInt
    fs ->
                            CInt -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a
    action (Int -> CInt
    intToCInt Int
    n) Ptr Oid
    ts Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs
      where
        AccumParams Int
    n [Oid]
    oids [Maybe (ByteString, Format)]
    values [CInt]
    c_lengths [CInt]
    formats =
            (Maybe (Oid, ByteString, Format) -> AccumParams -> AccumParams)
    -> AccumParams -> [Maybe (Oid, ByteString, Format)] -> AccumParams
    forall a b. (a -> b -> b) -> b -> [a] -> b
    forall (t :: * -> *) a b.
    Foldable t =>
    (a -> b -> b) -> b -> t a -> b
    foldr Maybe (Oid, ByteString, Format) -> AccumParams -> AccumParams
    accum (Int
    -> [Oid]
    -> [Maybe (ByteString, Format)]
    -> [CInt]
    -> [CInt]
    -> AccumParams
    AccumParams Int
    0 [] [] [] []) [Maybe (Oid, ByteString, Format)]
    params

        accum :: Maybe (Oid, B.ByteString, Format) -> AccumParams -> AccumParams
        accum :: Maybe (Oid, ByteString, Format) -> AccumParams -> AccumParams
    accum Maybe (Oid, ByteString, Format)
    Nothing ~(AccumParams Int
    i [Oid]
    a [Maybe (ByteString, Format)]
    b [CInt]
    c [CInt]
    d) =
            Int
    -> [Oid]
    -> [Maybe (ByteString, Format)]
    -> [CInt]
    -> [CInt]
    -> AccumParams
    AccumParams (Int
    i Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int
    1) (Oid
    invalidOid Oid -> [Oid] -> [Oid]
    forall a. a -> [a] -> [a]
    : [Oid]
    a) (Maybe (ByteString, Format)
    forall a. Maybe a
    Nothing Maybe (ByteString, Format)
    -> [Maybe (ByteString, Format)] -> [Maybe (ByteString, Format)]
    forall a. a -> [a] -> [a]
    : [Maybe (ByteString, Format)]
    b) (CInt
    0 CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    c) (CInt
    0 CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    d)

        accum (Just (Oid
    t,ByteString
    v,Format
    f)) ~(AccumParams Int
    i [Oid]
    xs [Maybe (ByteString, Format)]
    ys [CInt]
    zs [CInt]
    ws)  =
            let !z :: CInt
    z = Int -> CInt
    intToCInt (ByteString -> Int
    B.length ByteString
    v)
                !w :: CInt
    w = Format -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Format
    f
            in Int
    -> [Oid]
    -> [Maybe (ByteString, Format)]
    -> [CInt]
    -> [CInt]
    -> AccumParams
    AccumParams (Int
    i Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int
    1) (Oid
    t Oid -> [Oid] -> [Oid]
    forall a. a -> [a] -> [a]
    : [Oid]
    xs) ((ByteString, Format) -> Maybe (ByteString, Format)
    forall a. a -> Maybe a
    Just (ByteString
    v, Format
    f) Maybe (ByteString, Format)
    -> [Maybe (ByteString, Format)] -> [Maybe (ByteString, Format)]
    forall a. a -> [a] -> [a]
    : [Maybe (ByteString, Format)]
    ys) (CInt
    z CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    zs) (CInt
    w CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    ws)

    intToCInt :: Int -> CInt
    intToCInt :: Int -> CInt
    intToCInt = Int -> CInt
    forall a. Enum a => Int -> a
    toEnum

    data AccumParams = AccumParams !Int ![Oid] ![Maybe (B.ByteString, Format)] ![CInt] ![CInt]

    -- | Convert a list of parameters to the format expected by libpq FFI calls,
    -- prepared statement variant.
    withParamsPrepared :: [Maybe (B.ByteString, Format)]
                       -> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a)
                       -> IO a
    withParamsPrepared :: forall a.
    [Maybe (ByteString, Format)]
    -> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a) -> IO a
    withParamsPrepared [Maybe (ByteString, Format)]
    params CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a
    action =
        (Maybe (ByteString, Format) -> (CString -> IO a) -> IO a)
    -> [Maybe (ByteString, Format)] -> ([CString] -> IO a) -> IO a
    forall a b res.
    (a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res
    withMany (((ByteString, Format) -> (CString -> IO a) -> IO a)
    -> Maybe (ByteString, Format) -> (CString -> IO a) -> IO a
    forall a b c.
    (a -> (Ptr b -> IO c) -> IO c)
    -> Maybe a -> (Ptr b -> IO c) -> IO c
    maybeWith (ByteString, Format) -> (CString -> IO a) -> IO a
    forall a. (ByteString, Format) -> (CString -> IO a) -> IO a
    unsafeUseParamAsCString) [Maybe (ByteString, Format)]
    values (([CString] -> IO a) -> IO a) -> ([CString] -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \[CString]
    c_values ->
            Int -> [CString] -> (Ptr CString -> IO a) -> IO a
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
    unsafeWithArray Int
    n [CString]
    c_values ((Ptr CString -> IO a) -> IO a) -> (Ptr CString -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Ptr CString
    vs ->
                Int -> [CInt] -> (Ptr CInt -> IO a) -> IO a
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
    unsafeWithArray Int
    n [CInt]
    c_lengths ((Ptr CInt -> IO a) -> IO a) -> (Ptr CInt -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Ptr CInt
    ls ->
                    Int -> [CInt] -> (Ptr CInt -> IO a) -> IO a
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
    unsafeWithArray Int
    n [CInt]
    formats ((Ptr CInt -> IO a) -> IO a) -> (Ptr CInt -> IO a) -> IO a
    forall a b. (a -> b) -> a -> b
    $ \Ptr CInt
    fs ->
                        CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a
    action (Int -> CInt
    intToCInt Int
    n) Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs
      where
        AccumPrepParams Int
    n [Maybe (ByteString, Format)]
    values [CInt]
    c_lengths [CInt]
    formats =
            (Maybe (ByteString, Format) -> AccumPrepParams -> AccumPrepParams)
    -> AccumPrepParams
    -> [Maybe (ByteString, Format)]
    -> AccumPrepParams
    forall a b. (a -> b -> b) -> b -> [a] -> b
    forall (t :: * -> *) a b.
    Foldable t =>
    (a -> b -> b) -> b -> t a -> b
    foldr Maybe (ByteString, Format) -> AccumPrepParams -> AccumPrepParams
    accum (Int
    -> [Maybe (ByteString, Format)]
    -> [CInt]
    -> [CInt]
    -> AccumPrepParams
    AccumPrepParams Int
    0 [] [] []) [Maybe (ByteString, Format)]
    params

        accum :: Maybe (B.ByteString, Format) -> AccumPrepParams -> AccumPrepParams
        accum :: Maybe (ByteString, Format) -> AccumPrepParams -> AccumPrepParams
    accum Maybe (ByteString, Format)
    Nothing ~(AccumPrepParams Int
    i [Maybe (ByteString, Format)]
    a [CInt]
    b [CInt]
    c) =
            Int
    -> [Maybe (ByteString, Format)]
    -> [CInt]
    -> [CInt]
    -> AccumPrepParams
    AccumPrepParams (Int
    i Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int
    1) (Maybe (ByteString, Format)
    forall a. Maybe a
    Nothing Maybe (ByteString, Format)
    -> [Maybe (ByteString, Format)] -> [Maybe (ByteString, Format)]
    forall a. a -> [a] -> [a]
    : [Maybe (ByteString, Format)]
    a) (CInt
    0 CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    b) (CInt
    0 CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    c)

        accum (Just (ByteString
    v, Format
    f)) ~(AccumPrepParams Int
    i [Maybe (ByteString, Format)]
    xs [CInt]
    ys [CInt]
    zs) =
            let !y :: CInt
    y = Int -> CInt
    intToCInt (ByteString -> Int
    B.length ByteString
    v)
                !z :: CInt
    z = Format -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Format
    f
            in Int
    -> [Maybe (ByteString, Format)]
    -> [CInt]
    -> [CInt]
    -> AccumPrepParams
    AccumPrepParams (Int
    i Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int
    1) ((ByteString, Format) -> Maybe (ByteString, Format)
    forall a. a -> Maybe a
    Just (ByteString
    v, Format
    f) Maybe (ByteString, Format)
    -> [Maybe (ByteString, Format)] -> [Maybe (ByteString, Format)]
    forall a. a -> [a] -> [a]
    : [Maybe (ByteString, Format)]
    xs) (CInt
    y CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    ys) (CInt
    z CInt -> [CInt] -> [CInt]
    forall a. a -> [a] -> [a]
    : [CInt]
    zs)

    data AccumPrepParams = AccumPrepParams !Int ![Maybe (B.ByteString, Format)] ![CInt] ![CInt]

    -- | Submits a command to the server and waits for the result.
    --
    -- Returns a 'Result' or possibly 'Nothing'. A 'Result' will generally
    -- be returned except in out-of-memory conditions or serious errors
    -- such as inability to send the command to the server. If a 'Nothing'
    -- is returned, it should be treated like a 'FatalError' result. Use
    -- 'errorMessage' to get more information about such errors.
    --
    -- It is allowed to include multiple SQL commands (separated by
    -- semicolons) in the command string. Multiple queries sent in a
    -- single 'exec' call are processed in a single transaction, unless
    -- there are explicit BEGIN/COMMIT commands included in the query
    -- string to divide it into multiple transactions. Note however that
    -- the returned 'Result' structure describes only the result of the
    -- last command executed from the string. Should one of the commands
    -- fail, processing of the string stops with it and the returned
    -- 'Result' describes the error condition.
    exec :: Connection        -- ^ connection
         -> B.ByteString      -- ^ statement
         -> IO (Maybe Result) -- ^ result
    exec :: Connection -> ByteString -> IO (Maybe Result)
    exec Connection
    connection ByteString
    query =
        Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    resultFromConn Connection
    connection ((Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result))
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    p ->
            ByteString -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    query ((CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ Ptr PGconn -> CString -> IO (Ptr PGresult)
    c_PQexec Ptr PGconn
    p

    -- | Submits a command to the server and waits for the result, with
    -- the ability to pass parameters separately from the SQL command
    -- text.
    --
    -- 'execParams' is like 'exec', but offers additional functionality:
    -- parameter values can be specified separately from the command
    -- string proper, and query results can be requested in either text or
    -- binary format. 'execParams' is supported only in protocol 3.0 and
    -- later connections; it will fail when using protocol 2.0.
    --
    -- The primary advantage of 'execParams' over 'exec' is that parameter
    -- values can be separated from the command string, thus avoiding the
    -- need for tedious and error-prone quoting and escaping.
    --
    -- Unlike 'exec', 'execParams' allows at most one SQL command in the
    -- given string. (There can be semicolons in it, but not more than one
    -- nonempty command.) This is a limitation of the underlying protocol,
    -- but has some usefulness as an extra defense against SQL-injection
    -- attacks.
    --
    -- Tip: Specifying parameter types via OIDs is tedious, particularly
    -- if you prefer not to hard-wire particular OID values into your
    -- program. However, you can avoid doing so even in cases where the
    -- server by itself cannot determine the type of the parameter, or
    -- chooses a different type than you want. In the SQL command text,
    -- attach an explicit cast to the parameter symbol to show what data
    -- type you will send. For example:
    -- SELECT * FROM mytable WHERE x = $1::bigint;
    -- This forces parameter $1 to be treated as bigint, whereas by
    -- default it would be assigned the same type as x. Forcing the
    -- parameter type decision, either this way or by specifying a numeric
    -- type OID, is strongly recommended when sending parameter values in
    -- binary format, because binary format has less redundancy than text
    -- format and so there is less chance that the server will detect a
    -- type mismatch mistake for you.
    execParams :: Connection                          -- ^ connection
               -> B.ByteString                        -- ^ statement
               -> [Maybe (Oid, B.ByteString, Format)] -- ^ parameters
               -> Format                              -- ^ result format
               -> IO (Maybe Result)                   -- ^ result
    execParams :: Connection
    -> ByteString
    -> [Maybe (Oid, ByteString, Format)]
    -> Format
    -> IO (Maybe Result)
    execParams Connection
    connection ByteString
    statement [Maybe (Oid, ByteString, Format)]
    params Format
    rFmt =
        Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    resultFromConn Connection
    connection ((Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result))
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    statement ((CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                [Maybe (Oid, ByteString, Format)]
    -> (CInt
        -> Ptr Oid
        -> Ptr CString
        -> Ptr CInt
        -> Ptr CInt
        -> IO (Ptr PGresult))
    -> IO (Ptr PGresult)
    forall a.
    [Maybe (Oid, ByteString, Format)]
    -> (CInt -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a)
    -> IO a
    withParams [Maybe (Oid, ByteString, Format)]
    params ((CInt
      -> Ptr Oid
      -> Ptr CString
      -> Ptr CInt
      -> Ptr CInt
      -> IO (Ptr PGresult))
     -> IO (Ptr PGresult))
    -> (CInt
        -> Ptr Oid
        -> Ptr CString
        -> Ptr CInt
        -> Ptr CInt
        -> IO (Ptr PGresult))
    -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CInt
    n Ptr Oid
    ts Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs ->
                    Ptr PGconn
    -> CString
    -> CInt
    -> Ptr Oid
    -> Ptr CString
    -> Ptr CInt
    -> Ptr CInt
    -> CInt
    -> IO (Ptr PGresult)
    c_PQexecParams Ptr PGconn
    c CString
    s CInt
    n Ptr Oid
    ts Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs CInt
    f
      where
        !f :: CInt
    f = Format -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Format
    rFmt

    -- | Submits a request to create a prepared statement with the given
    -- parameters, and waits for completion.
    --
    -- 'prepare' creates a prepared statement for later execution with
    -- 'execPrepared'. This feature allows commands that will be used
    -- repeatedly to be parsed and planned just once, rather than each
    -- time they are executed. 'prepare' is supported only in protocol 3.0
    -- and later connections; it will fail when using protocol 2.0.
    --
    -- The function creates a prepared statement named stmtName from the
    -- query string, which must contain a single SQL command. stmtName can
    -- be \"\" to create an unnamed statement, in which case any
    -- pre-existing unnamed statement is automatically replaced; otherwise
    -- it is an error if the statement name is already defined in the
    -- current session. If any parameters are used, they are referred to
    -- in the query as $1, $2, etc. paramTypes specifies, by 'Oid', the
    -- data types to be assigned to the parameter symbols. If paramTypes
    -- is 'Nothing', or any particular element in the array is zero, the
    -- server assigns a data type to the parameter symbol in the same way
    -- it would do for an untyped literal string. Also, the query can use
    -- parameter symbols with numbers higher than the length of
    -- paramTypes; data types will be inferred for these symbols as
    -- well. (See 'describePrepared' for a means to find out what data
    -- types were inferred.)
    --
    -- As with 'exec', the result is normally a 'Result' whose contents
    -- indicate server-side success or failure. A 'Nothing' result
    -- indicates out-of-memory or inability to send the command at
    -- all. Use 'errorMessage' to get more information about such errors.
    --
    -- Prepared statements for use with 'execPrepared' can also be created
    -- by executing SQL PREPARE statements. (But 'prepare' is more
    -- flexible since it does not require parameter types to be
    -- pre-specified.) Also, although there is no libpq function for
    -- deleting a prepared statement, the SQL DEALLOCATE statement can be
    -- used for that purpose.
    prepare :: Connection        -- ^ connection
            -> B.ByteString      -- ^ stmtName
            -> B.ByteString      -- ^ query
            -> Maybe [Oid]       -- ^ paramTypes
            -> IO (Maybe Result) -- ^ result
    prepare :: Connection
    -> ByteString -> ByteString -> Maybe [Oid] -> IO (Maybe Result)
    prepare Connection
    connection ByteString
    stmtName ByteString
    query Maybe [Oid]
    mParamTypes =
        Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    resultFromConn Connection
    connection ((Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result))
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    stmtName ((CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                ByteString -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    query ((CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CString
    q ->
                    ([Oid]
     -> (Int -> Ptr Oid -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> Maybe [Oid]
    -> (Int -> Ptr Oid -> IO (Ptr PGresult))
    -> IO (Ptr PGresult)
    forall a b c.
    (a -> (Int -> Ptr b -> IO c) -> IO c)
    -> Maybe a -> (Int -> Ptr b -> IO c) -> IO c
    maybeWithInt [Oid] -> (Int -> Ptr Oid -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
    withArrayLen Maybe [Oid]
    mParamTypes ((Int -> Ptr Oid -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (Int -> Ptr Oid -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \Int
    l Ptr Oid
    o ->
                        Ptr PGconn
    -> CString -> CString -> CInt -> Ptr Oid -> IO (Ptr PGresult)
    c_PQprepare Ptr PGconn
    c CString
    s CString
    q (Int -> CInt
    intToCInt Int
    l) Ptr Oid
    o

    -- | Sends a request to execute a prepared statement with given
    -- parameters, and waits for the result.
    --
    -- 'execPrepared' is like 'execParams', but the command to be executed
    -- is specified by naming a previously-prepared statement, instead of
    -- giving a query string. This feature allows commands that will be
    -- used repeatedly to be parsed and planned just once, rather than
    -- each time they are executed. The statement must have been prepared
    -- previously in the current session. 'execPrepared' is supported only
    -- in protocol 3.0 and later connections; it will fail when using
    -- protocol 2.0.
    --
    -- The parameters are identical to 'execParams', except that the name
    -- of a prepared statement is given instead of a query string, and the
    -- paramTypes parameter is not present (it is not needed since the
    -- prepared statement's parameter types were determined when it was
    -- created).
    execPrepared :: Connection                     -- ^ connection
                 -> B.ByteString                   -- ^ stmtName
                 -> [Maybe (B.ByteString, Format)] -- ^ parameters
                 -> Format                         -- ^ result format
                 -> IO (Maybe Result)              -- ^ result
    execPrepared :: Connection
    -> ByteString
    -> [Maybe (ByteString, Format)]
    -> Format
    -> IO (Maybe Result)
    execPrepared Connection
    connection ByteString
    stmtName [Maybe (ByteString, Format)]
    params Format
    rFmt =
        Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    resultFromConn Connection
    connection ((Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result))
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    stmtName ((CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                [Maybe (ByteString, Format)]
    -> (CInt
        -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO (Ptr PGresult))
    -> IO (Ptr PGresult)
    forall a.
    [Maybe (ByteString, Format)]
    -> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a) -> IO a
    withParamsPrepared [Maybe (ByteString, Format)]
    params ((CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO (Ptr PGresult))
     -> IO (Ptr PGresult))
    -> (CInt
        -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO (Ptr PGresult))
    -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CInt
    n Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs ->
                    Ptr PGconn
    -> CString
    -> CInt
    -> Ptr CString
    -> Ptr CInt
    -> Ptr CInt
    -> CInt
    -> IO (Ptr PGresult)
    c_PQexecPrepared Ptr PGconn
    c CString
    s CInt
    n Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs CInt
    f
        where
          !f :: CInt
    f = Format -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Format
    rFmt

    -- | Submits a request to obtain information about the specified
    -- prepared statement, and waits for completion.
    --
    -- 'describePrepared' allows an application to obtain information
    -- about a previously prepared statement. 'describePrepared' is
    -- supported only in protocol 3.0 and later connections; it will fail
    -- when using protocol 2.0.
    --
    -- stmtName can be empty to reference the unnamed statement, otherwise
    -- it must be the name of an existing prepared statement. On success,
    -- a 'Result' with status 'CommandOk' is returned. The functions
    -- 'nparams' and 'paramtype' can be applied to this 'Result' to obtain
    -- information about the parameters of the prepared statement, and the
    -- functions 'nfields', 'fname', 'ftype', etc provide information
    -- about the result columns (if any) of the statement.
    describePrepared :: Connection
                     -> B.ByteString -- ^ stmtName
                     -> IO (Maybe Result)
    describePrepared :: Connection -> ByteString -> IO (Maybe Result)
    describePrepared Connection
    connection ByteString
    stmtName =
        Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    resultFromConn Connection
    connection ((Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result))
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    stmtName ((CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CString
    s -> Ptr PGconn -> CString -> IO (Ptr PGresult)
    c_PQdescribePrepared Ptr PGconn
    c CString
    s

    -- | Submits a request to obtain information about the specified
    -- portal, and waits for completion.
    --
    -- 'describePortal' allows an application to obtain information about
    -- a previously created portal. (libpq does not provide any direct
    -- access to portals, but you can use this function to inspect the
    -- properties of a cursor created with a DECLARE CURSOR SQL command.)
    -- 'describePortal' is supported only in protocol 3.0 and later
    -- connections; it will fail when using protocol 2.0.
    --
    -- portalName can be empty to reference the unnamed portal, otherwise
    -- it must be the name of an existing portal. On success, a 'Result'
    -- with status 'CommandOk' is returned. The functions 'nfields',
    -- 'fname', 'ftype', etc can be applied to the 'Result' to obtain
    -- information about the result columns (if any) of the portal.
    describePortal :: Connection
                   -> B.ByteString -- ^ portalName
                   -> IO (Maybe Result)
    describePortal :: Connection -> ByteString -> IO (Maybe Result)
    describePortal Connection
    connection ByteString
    portalName =
        Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    resultFromConn Connection
    connection ((Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result))
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    portalName ((CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult))
    -> (CString -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall a b. (a -> b) -> a -> b
    $ \CString
    p ->
                Ptr PGconn -> CString -> IO (Ptr PGresult)
    c_PQdescribePortal Ptr PGconn
    c CString
    p

    -- | Returns the result status of the command.
    resultStatus :: Result
                 -> IO ExecStatus
    resultStatus :: Result -> IO ExecStatus
    resultStatus Result
    result = Result -> (Ptr PGresult -> IO CInt) -> IO ExecStatus
    forall b. FromCInt b => Result -> (Ptr PGresult -> IO CInt) -> IO b
    enumFromResult Result
    result Ptr PGresult -> IO CInt
    c_PQresultStatus

    -- | Converts the 'ExecStatus' returned by 'resultStatus' into a
    -- string describing the status code. The caller should not
    -- free the result.
    resStatus :: ExecStatus
              -> IO B.ByteString
    resStatus :: ExecStatus -> IO ByteString
    resStatus ExecStatus
    es =
        do cstr <- CInt -> IO CString
    c_PQresStatus (CInt -> IO CString) -> CInt -> IO CString
    forall a b. (a -> b) -> a -> b
    $ ExecStatus -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt ExecStatus
    es
           len <- B.c_strlen cstr
           fp <- newForeignPtr_ $ castPtr cstr
           return $ B.fromForeignPtr fp 0 $ fromIntegral len

    -- | Returns the error message associated with the command, or an
    -- empty string if there was no error.
    resultErrorMessage :: Result
                       -> IO (Maybe B.ByteString)
    resultErrorMessage :: Result -> IO (Maybe ByteString)
    resultErrorMessage = (Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString))
    -> (Ptr PGresult -> IO CString) -> Result -> IO (Maybe ByteString)
    forall a b c. (a -> b -> c) -> b -> a -> c
    flip Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromResult Ptr PGresult -> IO CString
    c_PQresultErrorMessage

    -- | Frees the memory associated with a result.  Note that using this
    -- function correctly is especially tricky;  you need to ensure that
    -- no references to the result.   This means no references to a value
    -- returned by 'getvalue',  no references hiding inside an unevaluated
    -- thunk,  etc.    Improper use of this function is likely to cause a
    -- segfault.   Also,  the use of this function is not strictly necessary;
    -- the memory will get freed by the garbage collector when there are no
    -- more references to the result.

    unsafeFreeResult :: Result -> IO ()
    unsafeFreeResult :: Result -> IO ()
    unsafeFreeResult (Result ForeignPtr PGresult
    x) = ForeignPtr PGresult -> IO ()
    forall a. ForeignPtr a -> IO ()
    finalizeForeignPtr ForeignPtr PGresult
    x

    -- | Returns an individual field of an error report.
    --
    -- fieldcode is an error field identifier; see the symbols listed
    -- below. 'Nothing' is returned if the PGresult is not an error or
    -- warning result, or does not include the specified field. Field
    -- values will normally not include a trailing newline.
    --
    -- The client is responsible for formatting displayed information to
    -- meet its needs; in particular it should break long lines as
    -- needed. Newline characters appearing in the error message fields
    -- should be treated as paragraph breaks, not line breaks.
    --
    -- Errors generated internally by libpq will have severity and primary
    -- message, but typically no other fields. Errors returned by a
    -- pre-3.0-protocol server will include severity and primary message,
    -- and sometimes a detail message, but no other fields.
    --
    -- Note that error fields are only available from 'Result' objects,
    -- not 'Connection' objects; there is no errorField function.
    resultErrorField :: Result
                     -> FieldCode
                     -> IO (Maybe B.ByteString)
    resultErrorField :: Result -> FieldCode -> IO (Maybe ByteString)
    resultErrorField (Result ForeignPtr PGresult
    fp) FieldCode
    fieldcode =
        ForeignPtr PGresult
    -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    forall a.
    ForeignPtr a -> (Ptr a -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromForeignPtr ForeignPtr PGresult
    fp ((Ptr PGresult -> IO CString) -> IO (Maybe ByteString))
    -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    res ->
            Ptr PGresult -> CInt -> IO CString
    c_PQresultErrorField Ptr PGresult
    res (CInt -> IO CString) -> CInt -> IO CString
    forall a b. (a -> b) -> a -> b
    $ FieldCode -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt FieldCode
    fieldcode

    -- $queryresultinfo
    -- These functions are used to extract information from a 'Result'
    -- that represents a successful query result (that is, one that has
    -- status 'TuplesOk'). They can also be used to extract information
    -- from a successful Describe operation: a Describe's result has all
    -- the same column information that actual execution of the query
    -- would provide, but it has zero rows. For objects with other status
    -- values, these functions will act as though the result has zero rows
    -- and zero columns.

    -- | Returns the number of rows (tuples) in the query result.  (Note
    -- that PGresult objects are limited to no more than INT_MAX rows, so
    -- an int result is sufficient.)
    ntuples :: Result
            -> IO Row
    ntuples :: Result -> IO Row
    ntuples Result
    res = Result -> (Ptr PGresult -> IO Row) -> IO Row
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    res (Row -> IO Row
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Row -> IO Row) -> (Ptr PGresult -> Row) -> Ptr PGresult -> IO Row
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . CInt -> Row
    forall a. Integral a => a -> Row
    toRow (CInt -> Row) -> (Ptr PGresult -> CInt) -> Ptr PGresult -> Row
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Ptr PGresult -> CInt
    c_PQntuples)

    -- | Returns the number of columns (fields) in each row of the query
    -- result.
    nfields :: Result
            -> IO Column
    nfields :: Result -> IO Column
    nfields Result
    res = Result -> (Ptr PGresult -> IO Column) -> IO Column
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    res (Column -> IO Column
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Column -> IO Column)
    -> (Ptr PGresult -> Column) -> Ptr PGresult -> IO Column
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . CInt -> Column
    forall a. Integral a => a -> Column
    toColumn (CInt -> Column)
    -> (Ptr PGresult -> CInt) -> Ptr PGresult -> Column
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Ptr PGresult -> CInt
    c_PQnfields)

    newtype Column = Col CInt
      deriving stock (Column -> Column -> Bool
    (Column -> Column -> Bool)
    -> (Column -> Column -> Bool) -> Eq Column
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: Column -> Column -> Bool
    == :: Column -> Column -> Bool
    $c/= :: Column -> Column -> Bool
    /= :: Column -> Column -> Bool
    Eq, Eq Column
    Eq Column =>
    (Column -> Column -> Ordering)
    -> (Column -> Column -> Bool)
    -> (Column -> Column -> Bool)
    -> (Column -> Column -> Bool)
    -> (Column -> Column -> Bool)
    -> (Column -> Column -> Column)
    -> (Column -> Column -> Column)
    -> Ord Column
    Column -> Column -> Bool
    Column -> Column -> Ordering
    Column -> Column -> Column
    forall a.
    Eq a =>
    (a -> a -> Ordering)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> a)
    -> (a -> a -> a)
    -> Ord a
    $ccompare :: Column -> Column -> Ordering
    compare :: Column -> Column -> Ordering
    $c< :: Column -> Column -> Bool
    < :: Column -> Column -> Bool
    $c<= :: Column -> Column -> Bool
    <= :: Column -> Column -> Bool
    $c> :: Column -> Column -> Bool
    > :: Column -> Column -> Bool
    $c>= :: Column -> Column -> Bool
    >= :: Column -> Column -> Bool
    $cmax :: Column -> Column -> Column
    max :: Column -> Column -> Column
    $cmin :: Column -> Column -> Column
    min :: Column -> Column -> Column
    Ord, Int -> Column -> [Char] -> [Char]
    [Column] -> [Char] -> [Char]
    Column -> [Char]
    (Int -> Column -> [Char] -> [Char])
    -> (Column -> [Char])
    -> ([Column] -> [Char] -> [Char])
    -> Show Column
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> Column -> [Char] -> [Char]
    showsPrec :: Int -> Column -> [Char] -> [Char]
    $cshow :: Column -> [Char]
    show :: Column -> [Char]
    $cshowList :: [Column] -> [Char] -> [Char]
    showList :: [Column] -> [Char] -> [Char]
    Show)
      deriving newtype (Int -> Column
    Column -> Int
    Column -> [Column]
    Column -> Column
    Column -> Column -> [Column]
    Column -> Column -> Column -> [Column]
    (Column -> Column)
    -> (Column -> Column)
    -> (Int -> Column)
    -> (Column -> Int)
    -> (Column -> [Column])
    -> (Column -> Column -> [Column])
    -> (Column -> Column -> [Column])
    -> (Column -> Column -> Column -> [Column])
    -> Enum Column
    forall a.
    (a -> a)
    -> (a -> a)
    -> (Int -> a)
    -> (a -> Int)
    -> (a -> [a])
    -> (a -> a -> [a])
    -> (a -> a -> [a])
    -> (a -> a -> a -> [a])
    -> Enum a
    $csucc :: Column -> Column
    succ :: Column -> Column
    $cpred :: Column -> Column
    pred :: Column -> Column
    $ctoEnum :: Int -> Column
    toEnum :: Int -> Column
    $cfromEnum :: Column -> Int
    fromEnum :: Column -> Int
    $cenumFrom :: Column -> [Column]
    enumFrom :: Column -> [Column]
    $cenumFromThen :: Column -> Column -> [Column]
    enumFromThen :: Column -> Column -> [Column]
    $cenumFromTo :: Column -> Column -> [Column]
    enumFromTo :: Column -> Column -> [Column]
    $cenumFromThenTo :: Column -> Column -> Column -> [Column]
    enumFromThenTo :: Column -> Column -> Column -> [Column]
    Enum, Integer -> Column
    Column -> Column
    Column -> Column -> Column
    (Column -> Column -> Column)
    -> (Column -> Column -> Column)
    -> (Column -> Column -> Column)
    -> (Column -> Column)
    -> (Column -> Column)
    -> (Column -> Column)
    -> (Integer -> Column)
    -> Num Column
    forall a.
    (a -> a -> a)
    -> (a -> a -> a)
    -> (a -> a -> a)
    -> (a -> a)
    -> (a -> a)
    -> (a -> a)
    -> (Integer -> a)
    -> Num a
    $c+ :: Column -> Column -> Column
    + :: Column -> Column -> Column
    $c- :: Column -> Column -> Column
    - :: Column -> Column -> Column
    $c* :: Column -> Column -> Column
    * :: Column -> Column -> Column
    $cnegate :: Column -> Column
    negate :: Column -> Column
    $cabs :: Column -> Column
    abs :: Column -> Column
    $csignum :: Column -> Column
    signum :: Column -> Column
    $cfromInteger :: Integer -> Column
    fromInteger :: Integer -> Column
    Num)
    newtype Row    = Row CInt
      deriving stock (Row -> Row -> Bool
    (Row -> Row -> Bool) -> (Row -> Row -> Bool) -> Eq Row
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: Row -> Row -> Bool
    == :: Row -> Row -> Bool
    $c/= :: Row -> Row -> Bool
    /= :: Row -> Row -> Bool
    Eq, Eq Row
    Eq Row =>
    (Row -> Row -> Ordering)
    -> (Row -> Row -> Bool)
    -> (Row -> Row -> Bool)
    -> (Row -> Row -> Bool)
    -> (Row -> Row -> Bool)
    -> (Row -> Row -> Row)
    -> (Row -> Row -> Row)
    -> Ord Row
    Row -> Row -> Bool
    Row -> Row -> Ordering
    Row -> Row -> Row
    forall a.
    Eq a =>
    (a -> a -> Ordering)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> a)
    -> (a -> a -> a)
    -> Ord a
    $ccompare :: Row -> Row -> Ordering
    compare :: Row -> Row -> Ordering
    $c< :: Row -> Row -> Bool
    < :: Row -> Row -> Bool
    $c<= :: Row -> Row -> Bool
    <= :: Row -> Row -> Bool
    $c> :: Row -> Row -> Bool
    > :: Row -> Row -> Bool
    $c>= :: Row -> Row -> Bool
    >= :: Row -> Row -> Bool
    $cmax :: Row -> Row -> Row
    max :: Row -> Row -> Row
    $cmin :: Row -> Row -> Row
    min :: Row -> Row -> Row
    Ord, Int -> Row -> [Char] -> [Char]
    [Row] -> [Char] -> [Char]
    Row -> [Char]
    (Int -> Row -> [Char] -> [Char])
    -> (Row -> [Char]) -> ([Row] -> [Char] -> [Char]) -> Show Row
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> Row -> [Char] -> [Char]
    showsPrec :: Int -> Row -> [Char] -> [Char]
    $cshow :: Row -> [Char]
    show :: Row -> [Char]
    $cshowList :: [Row] -> [Char] -> [Char]
    showList :: [Row] -> [Char] -> [Char]
    Show)
      deriving newtype (Int -> Row
    Row -> Int
    Row -> [Row]
    Row -> Row
    Row -> Row -> [Row]
    Row -> Row -> Row -> [Row]
    (Row -> Row)
    -> (Row -> Row)
    -> (Int -> Row)
    -> (Row -> Int)
    -> (Row -> [Row])
    -> (Row -> Row -> [Row])
    -> (Row -> Row -> [Row])
    -> (Row -> Row -> Row -> [Row])
    -> Enum Row
    forall a.
    (a -> a)
    -> (a -> a)
    -> (Int -> a)
    -> (a -> Int)
    -> (a -> [a])
    -> (a -> a -> [a])
    -> (a -> a -> [a])
    -> (a -> a -> a -> [a])
    -> Enum a
    $csucc :: Row -> Row
    succ :: Row -> Row
    $cpred :: Row -> Row
    pred :: Row -> Row
    $ctoEnum :: Int -> Row
    toEnum :: Int -> Row
    $cfromEnum :: Row -> Int
    fromEnum :: Row -> Int
    $cenumFrom :: Row -> [Row]
    enumFrom :: Row -> [Row]
    $cenumFromThen :: Row -> Row -> [Row]
    enumFromThen :: Row -> Row -> [Row]
    $cenumFromTo :: Row -> Row -> [Row]
    enumFromTo :: Row -> Row -> [Row]
    $cenumFromThenTo :: Row -> Row -> Row -> [Row]
    enumFromThenTo :: Row -> Row -> Row -> [Row]
    Enum, Integer -> Row
    Row -> Row
    Row -> Row -> Row
    (Row -> Row -> Row)
    -> (Row -> Row -> Row)
    -> (Row -> Row -> Row)
    -> (Row -> Row)
    -> (Row -> Row)
    -> (Row -> Row)
    -> (Integer -> Row)
    -> Num Row
    forall a.
    (a -> a -> a)
    -> (a -> a -> a)
    -> (a -> a -> a)
    -> (a -> a)
    -> (a -> a)
    -> (a -> a)
    -> (Integer -> a)
    -> Num a
    $c+ :: Row -> Row -> Row
    + :: Row -> Row -> Row
    $c- :: Row -> Row -> Row
    - :: Row -> Row -> Row
    $c* :: Row -> Row -> Row
    * :: Row -> Row -> Row
    $cnegate :: Row -> Row
    negate :: Row -> Row
    $cabs :: Row -> Row
    abs :: Row -> Row
    $csignum :: Row -> Row
    signum :: Row -> Row
    $cfromInteger :: Integer -> Row
    fromInteger :: Integer -> Row
    Num)

    toColumn :: (Integral a) => a -> Column
    toColumn :: forall a. Integral a => a -> Column
    toColumn = CInt -> Column
    Col (CInt -> Column) -> (a -> CInt) -> a -> Column
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . a -> CInt
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral

    toRow :: (Integral a) => a -> Row
    toRow :: forall a. Integral a => a -> Row
    toRow = CInt -> Row
    Row (CInt -> Row) -> (a -> CInt) -> a -> Row
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . a -> CInt
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral

    -- | Returns the column name associated with the given 'Column'
    -- number. Column numbers start at 0.
    fname :: Result
          -> Column
          -> IO (Maybe B.ByteString)
    fname :: Result -> Column -> IO (Maybe ByteString)
    fname Result
    result (Col CInt
    colNum) =
        Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromResult Result
    result ((Ptr PGresult -> IO CString) -> IO (Maybe ByteString))
    -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    fp ->
            Ptr PGresult -> CInt -> IO CString
    c_PQfname Ptr PGresult
    fp CInt
    colNum

    -- | Returns the column number associated with the given column name.
    fnumber :: Result
            -> B.ByteString
            -> IO (Maybe Column)
    fnumber :: Result -> ByteString -> IO (Maybe Column)
    fnumber Result
    res ByteString
    columnName =
        do num <- Result -> (Ptr PGresult -> IO CInt) -> IO CInt
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    res ((Ptr PGresult -> IO CInt) -> IO CInt)
    -> (Ptr PGresult -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    resPtr ->
                  ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    columnName ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    columnNamePtr ->
                      Ptr PGresult -> CString -> IO CInt
    c_PQfnumber Ptr PGresult
    resPtr CString
    columnNamePtr
           if num == -1
             then return Nothing
             else return $ Just $ toColumn num

    -- | Returns the OID of the table from which the given column was
    -- fetched. Column numbers start at 0.
    ftable :: Result
           -> Column
           -> IO Oid
    ftable :: Result -> Column -> IO Oid
    ftable Result
    result (Col CInt
    colNum) = Result -> (Ptr PGresult -> IO Oid) -> IO Oid
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    result ((Ptr PGresult -> IO Oid) -> IO Oid)
    -> (Ptr PGresult -> IO Oid) -> IO Oid
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr -> Ptr PGresult -> CInt -> IO Oid
    c_PQftable Ptr PGresult
    ptr CInt
    colNum

    -- | Returns the column number (within its table) of the column making
    -- up the specified query result column. Query-result column numbers
    -- start at 0, but table columns have nonzero numbers.
    ftablecol :: Result
              -> Column
              -> IO Column
    ftablecol :: Result -> Column -> IO Column
    ftablecol Result
    result (Col CInt
    colNum) =
        (CInt -> Column) -> IO CInt -> IO Column
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap CInt -> Column
    Col (IO CInt -> IO Column) -> IO CInt -> IO Column
    forall a b. (a -> b) -> a -> b
    $ Result -> (Ptr PGresult -> IO CInt) -> IO CInt
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    result ((Ptr PGresult -> IO CInt) -> IO CInt)
    -> (Ptr PGresult -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    p -> Ptr PGresult -> CInt -> IO CInt
    c_PQftablecol Ptr PGresult
    p CInt
    colNum

    -- | Returns the 'Format' of the given column. Column numbers start at
    -- 0.
    fformat :: Result
            -> Column
            -> IO Format
    fformat :: Result -> Column -> IO Format
    fformat Result
    result (Col CInt
    colNum) =
        Result -> (Ptr PGresult -> IO CInt) -> IO Format
    forall b. FromCInt b => Result -> (Ptr PGresult -> IO CInt) -> IO b
    enumFromResult Result
    result ((Ptr PGresult -> IO CInt) -> IO Format)
    -> (Ptr PGresult -> IO CInt) -> IO Format
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr -> Ptr PGresult -> CInt -> IO CInt
    c_PQfformat Ptr PGresult
    ptr CInt
    colNum

    -- | Returns the data type associated with the given column
    -- number. The 'Oid' returned is the internal OID number of the
    -- type. Column numbers start at 0.
    --
    -- You can query the system table pg_type to obtain the names and
    -- properties of the various data types. The OIDs of the built-in data
    -- types are defined in the file src/include/catalog/pg_type.h in the
    -- source tree.
    ftype :: Result
          -> Column
          -> IO Oid
    ftype :: Result -> Column -> IO Oid
    ftype Result
    result (Col CInt
    colNum) = Result -> (Ptr PGresult -> IO Oid) -> IO Oid
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    result ((Ptr PGresult -> IO Oid) -> IO Oid)
    -> (Ptr PGresult -> IO Oid) -> IO Oid
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr -> Ptr PGresult -> CInt -> IO Oid
    c_PQftype Ptr PGresult
    ptr CInt
    colNum

    -- | Returns the type modifier of the column associated with the given
    -- column number. Column numbers start at 0.
    --
    -- The interpretation of modifier values is type-specific; they
    -- typically indicate precision or size limits. The value -1 is used
    -- to indicate "no information available". Most data types do not use
    -- modifiers, in which case the value is always -1.
    fmod :: Result
         -> Column
         -> IO Int
    fmod :: Result -> Column -> IO Int
    fmod Result
    result (Col CInt
    colNum) = Result -> (Ptr PGresult -> IO CInt) -> IO Int
    forall a b.
    (Integral a, Num b) =>
    Result -> (Ptr PGresult -> IO a) -> IO b
    numFromResult Result
    result ((Ptr PGresult -> IO CInt) -> IO Int)
    -> (Ptr PGresult -> IO CInt) -> IO Int
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr -> Ptr PGresult -> CInt -> IO CInt
    c_PQfmod Ptr PGresult
    ptr CInt
    colNum

    -- | Returns the size in bytes of the column associated with the given
    -- column number. Column numbers start at 0.
    --
    -- 'fsize' returns the space allocated for this column in a database
    -- row, in other words the size of the server's internal
    -- representation of the data type. (Accordingly, it is not really
    -- very useful to clients.) A negative value indicates the data type
    -- is variable-length.
    fsize :: Result
          -> Column
          -> IO Int
    fsize :: Result -> Column -> IO Int
    fsize Result
    result (Col CInt
    colNum) = Result -> (Ptr PGresult -> IO CInt) -> IO Int
    forall a b.
    (Integral a, Num b) =>
    Result -> (Ptr PGresult -> IO a) -> IO b
    numFromResult Result
    result ((Ptr PGresult -> IO CInt) -> IO Int)
    -> (Ptr PGresult -> IO CInt) -> IO Int
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr -> Ptr PGresult -> CInt -> IO CInt
    c_PQfsize Ptr PGresult
    ptr CInt
    colNum

    -- | Returns a single field value of one row of a PGresult. Row and
    -- column numbers start at 0.
    --
    -- For convenience, this binding uses 'getisnull' and 'getlength' to
    -- help construct the result.
    --
    -- Note: The 'ByteString' returned holds a reference to the Result. As
    -- long as ByteString is live, the Result will not be garbage
    -- collected. 'getvalue'' returns a copy of the data.
    getvalue :: Result
             -> Row
             -> Column
             -> IO (Maybe B.ByteString)
    getvalue :: Result -> Row -> Column -> IO (Maybe ByteString)
    getvalue (Result ForeignPtr PGresult
    fp) (Row CInt
    rowNum) (Col CInt
    colNum) =
        ForeignPtr PGresult
    -> (Ptr PGresult -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
    withForeignPtr ForeignPtr PGresult
    fp ((Ptr PGresult -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGresult -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr -> do
          isnull <- Ptr PGresult -> CInt -> CInt -> IO CInt
    c_PQgetisnull Ptr PGresult
    ptr CInt
    rowNum CInt
    colNum
          case fromCInt isnull of
            Just Bool
    True  -> Maybe ByteString -> IO (Maybe ByteString)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe ByteString
    forall a. Maybe a
    Nothing
            Just Bool
    False -> do
              cstr <- Ptr PGresult -> CInt -> CInt -> IO CString
    c_PQgetvalue Ptr PGresult
    ptr CInt
    rowNum CInt
    colNum
              l <- c_PQgetlength ptr rowNum colNum
              fp' <- FC.newForeignPtr (castPtr cstr) finalizer
              return $! Just $! B.fromForeignPtr fp' 0 $ fromIntegral l
            Maybe Bool
    Nothing -> [Char] -> IO (Maybe ByteString)
    forall a. [Char] -> IO a
    forall (m :: * -> *) a. MonadFail m => [Char] -> m a
    fail ([Char] -> IO (Maybe ByteString))
    -> [Char] -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ [Char]
    "fromCInt @Bool " [Char] -> [Char] -> [Char]
    forall a. [a] -> [a] -> [a]
    ++ CInt -> [Char]
    forall a. Show a => a -> [Char]
    show CInt
    isnull

        where
          finalizer :: IO ()
    finalizer = ForeignPtr PGresult -> IO ()
    forall a. ForeignPtr a -> IO ()
    touchForeignPtr ForeignPtr PGresult
    fp

    -- | Returns a copy of a single field value of one row of a
    -- PGresult. Row and column numbers start at 0.
    --
    -- For convenience, this binding uses 'getisnull' and 'getlength' to
    -- help construct the result.
    getvalue' :: Result
              -> Row
              -> Column
              -> IO (Maybe B.ByteString)
    getvalue' :: Result -> Row -> Column -> IO (Maybe ByteString)
    getvalue' Result
    res (Row CInt
    rowNum) (Col CInt
    colNum) =
        Result
    -> (Ptr PGresult -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    res ((Ptr PGresult -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGresult -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr -> do
          isnull <- Ptr PGresult -> CInt -> CInt -> IO CInt
    c_PQgetisnull Ptr PGresult
    ptr CInt
    rowNum CInt
    colNum
          case fromCInt isnull of
            Just Bool
    True  -> Maybe ByteString -> IO (Maybe ByteString)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe ByteString
    forall a. Maybe a
    Nothing
            Just Bool
    False -> do
              cstr <- Ptr PGresult -> CInt -> CInt -> IO CString
    c_PQgetvalue Ptr PGresult
    ptr CInt
    rowNum CInt
    colNum
              l <- fromIntegral `fmap` c_PQgetlength ptr rowNum colNum
              Just `fmap` B.packCStringLen (cstr, l)
            Maybe Bool
    Nothing -> [Char] -> IO (Maybe ByteString)
    forall a. [Char] -> IO a
    forall (m :: * -> *) a. MonadFail m => [Char] -> m a
    fail ([Char] -> IO (Maybe ByteString))
    -> [Char] -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ [Char]
    "fromCInt @Bool " [Char] -> [Char] -> [Char]
    forall a. [a] -> [a] -> [a]
    ++ CInt -> [Char]
    forall a. Show a => a -> [Char]
    show CInt
    isnull

    -- | Tests a field for a null value. Row and column numbers start at
    -- 0.
    getisnull :: Result
              -> Row
              -> Column
              -> IO Bool
    getisnull :: Result -> Row -> Column -> IO Bool
    getisnull Result
    result (Row CInt
    rowNum) (Col CInt
    colNum) =
        Result -> (Ptr PGresult -> IO CInt) -> IO Bool
    forall b. FromCInt b => Result -> (Ptr PGresult -> IO CInt) -> IO b
    enumFromResult Result
    result ((Ptr PGresult -> IO CInt) -> IO Bool)
    -> (Ptr PGresult -> IO CInt) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr ->
            Ptr PGresult -> CInt -> CInt -> IO CInt
    c_PQgetisnull Ptr PGresult
    ptr CInt
    rowNum CInt
    colNum

    -- | Returns the actual length of a field value in bytes. Row and
    -- column numbers start at 0.
    --
    -- This is the actual data length for the particular data value, that
    -- is, the size of the object pointed to by 'getvalue'. For text data
    -- format this is the same as strlen(). For binary format this is
    -- essential information. Note that one should not rely on 'fsize' to
    -- obtain the actual data length.
    getlength :: Result
              -> Row
              -> Column
              -> IO Int
    getlength :: Result -> Row -> Column -> IO Int
    getlength Result
    result (Row CInt
    rowNum) (Col CInt
    colNum) =
        Result -> (Ptr PGresult -> IO CInt) -> IO Int
    forall a b.
    (Integral a, Num b) =>
    Result -> (Ptr PGresult -> IO a) -> IO b
    numFromResult Result
    result ((Ptr PGresult -> IO CInt) -> IO Int)
    -> (Ptr PGresult -> IO CInt) -> IO Int
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    ptr ->
          Ptr PGresult -> CInt -> CInt -> IO CInt
    c_PQgetlength Ptr PGresult
    ptr CInt
    rowNum CInt
    colNum

    -- | Returns the number of parameters of a prepared statement.
    --
    -- This function is only useful when inspecting the result of
    -- PQdescribePrepared. For other types of queries it will return zero.
    nparams :: Result
            -> IO Int
    nparams :: Result -> IO Int
    nparams Result
    result = Result -> (Ptr PGresult -> IO CInt) -> IO Int
    forall a b.
    (Integral a, Num b) =>
    Result -> (Ptr PGresult -> IO a) -> IO b
    numFromResult Result
    result Ptr PGresult -> IO CInt
    c_PQnparams

    -- | Returns the data type of the indicated statement
    -- parameter. Parameter numbers start at 0.
    --
    -- This function is only useful when inspecting the result of
    -- 'describePrepared'. For other types of queries it will return zero.
    paramtype :: Result
              -> Int -- ^ param_number
              -> IO Oid
    paramtype :: Result -> Int -> IO Oid
    paramtype Result
    result Int
    param_number =
        Result -> (Ptr PGresult -> IO Oid) -> IO Oid
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    result ((Ptr PGresult -> IO Oid) -> IO Oid)
    -> (Ptr PGresult -> IO Oid) -> IO Oid
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGresult
    p -> Ptr PGresult -> CInt -> IO Oid
    c_PQparamtype Ptr PGresult
    p (CInt -> IO Oid) -> CInt -> IO Oid
    forall a b. (a -> b) -> a -> b
    $ Int -> CInt
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    param_number

    -- $othercommands
    -- These functions are used to extract other information from PGresult
    -- objects.

    -- | Returns the command status tag from the SQL command that
    -- generated the PGresult.
    --
    -- Commonly this is just the name of the command, but it might include
    -- additional data such as the number of rows processed.
    cmdStatus :: Result
              -> IO (Maybe B.ByteString)
    cmdStatus :: Result -> IO (Maybe ByteString)
    cmdStatus = (Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString))
    -> (Ptr PGresult -> IO CString) -> Result -> IO (Maybe ByteString)
    forall a b c. (a -> b -> c) -> b -> a -> c
    flip Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromResult Ptr PGresult -> IO CString
    c_PQcmdStatus

    -- | Returns the number of rows affected by the SQL command.
    --
    -- This function returns a string containing the number of rows
    -- affected by the SQL statement that generated the 'Result'. This
    -- function can only be used following the execution of a SELECT,
    -- CREATE TABLE AS, INSERT, UPDATE, DELETE, MOVE, FETCH, or COPY
    -- statement, or an EXECUTE of a prepared query that contains an
    -- INSERT, UPDATE, or DELETE statement. If the command that generated
    -- the 'Result' was anything else, 'cmdTuples' returns an empty
    -- string.
    cmdTuples :: Result
              -> IO (Maybe B.ByteString)
    cmdTuples :: Result -> IO (Maybe ByteString)
    cmdTuples = (Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString))
    -> (Ptr PGresult -> IO CString) -> Result -> IO (Maybe ByteString)
    forall a b c. (a -> b -> c) -> b -> a -> c
    flip Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromResult Ptr PGresult -> IO CString
    c_PQcmdTuples

    -- | Escapes a string for use within an SQL command. This is useful
    -- when inserting data values as literal constants in SQL
    -- commands. Certain characters (such as quotes and backslashes) must
    -- be escaped to prevent them from being interpreted specially by the
    -- SQL parser.
    escapeStringConn :: Connection
                     -> B.ByteString
                     -> IO (Maybe B.ByteString)
    escapeStringConn :: Connection -> ByteString -> IO (Maybe ByteString)
    escapeStringConn Connection
    connection ByteString
    bs =
      Connection
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    conn ->
        ByteString
    -> (CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
    B.unsafeUseAsCStringLen ByteString
    bs ((CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \(CString
    from, Int
    bslen) ->
          (Ptr CInt -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. Storable a => (Ptr a -> IO b) -> IO b
    alloca ((Ptr CInt -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr CInt -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr CInt
    err -> do
            xs <- Int -> (Ptr Word8 -> IO Int) -> IO ByteString
    B.createAndTrim (Int
    bslenInt -> Int -> Int
    forall a. Num a => a -> a -> a
    *Int
    2Int -> Int -> Int
    forall a. Num a => a -> a -> a
    +Int
    1) ((Ptr Word8 -> IO Int) -> IO ByteString)
    -> (Ptr Word8 -> IO Int) -> IO ByteString
    forall a b. (a -> b) -> a -> b
    $ \Ptr Word8
    to ->
                     CSize -> Int
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (CSize -> Int) -> IO CSize -> IO Int
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    `fmap`
                       Ptr PGconn -> Ptr Word8 -> CString -> CSize -> Ptr CInt -> IO CSize
    c_PQescapeStringConn Ptr PGconn
    conn Ptr Word8
    to CString
    from (Int -> CSize
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    bslen) Ptr CInt
    err
            stat <- peek err
            case stat of
              CInt
    0 -> Maybe ByteString -> IO (Maybe ByteString)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Maybe ByteString -> IO (Maybe ByteString))
    -> Maybe ByteString -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ ByteString -> Maybe ByteString
    forall a. a -> Maybe a
    Just ByteString
    xs
              CInt
    _ -> Maybe ByteString -> IO (Maybe ByteString)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe ByteString
    forall a. Maybe a
    Nothing

    -- | Escapes binary data for use within an SQL command with the type
    -- bytea. As with 'escapeStringConn', this is only used when inserting
    -- data directly into an SQL command string.
    escapeByteaConn :: Connection
                    -> B.ByteString
                    -> IO (Maybe B.ByteString)
    escapeByteaConn :: Connection -> ByteString -> IO (Maybe ByteString)
    escapeByteaConn Connection
    connection ByteString
    bs =
        Connection
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    conn ->
            ByteString
    -> (CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
    B.unsafeUseAsCStringLen ByteString
    bs ((CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \(CString
    from, Int
    bslen) ->
                (Ptr CSize -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. Storable a => (Ptr a -> IO b) -> IO b
    alloca ((Ptr CSize -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr CSize -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr CSize
    to_length -> do
                  to <- Ptr PGconn -> CString -> CSize -> Ptr CSize -> IO (Ptr Word8)
    c_PQescapeByteaConn Ptr PGconn
    conn CString
    from (Int -> CSize
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    bslen) Ptr CSize
    to_length
                  if to == nullPtr
                    then return Nothing
                    else do tofp <- newForeignPtr p_PQfreemem to
                            l <- peek to_length
                            return $! Just $! B.fromForeignPtr tofp 0 ((fromIntegral l) - 1)

    -- | Converts a 'ByteString' representation of binary data into binary
    -- data - the reverse of 'PQescapeByteaConn'. This is needed when
    -- retrieving bytea data in text format, but not when retrieving it in
    -- binary format.
    --
    -- The parameter points to a string such as might be returned by
    -- 'getvalue' when applied to a bytea column. 'unescapeBytea' converts
    -- this string representation into its binary representation. It
    -- returns a 'ByteString', or 'Nothing' on error.
    --
    -- This conversion is not exactly the inverse of 'escapeByteaConn',
    -- because the string is not expected to be "escaped" when received
    -- from 'getvalue'. In particular this means there is no need for
    -- string quoting considerations, and so no need for a 'Connection'
    -- parameter.
    unescapeBytea :: B.ByteString
                  -> IO (Maybe B.ByteString)
    unescapeBytea :: ByteString -> IO (Maybe ByteString)
    unescapeBytea ByteString
    bs =
        ByteString
    -> (CString -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    bs ((CString -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (CString -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \CString
    from ->
            (Ptr CSize -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. Storable a => (Ptr a -> IO b) -> IO b
    alloca ((Ptr CSize -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr CSize -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr CSize
    to_length -> do
              to <- CString -> Ptr CSize -> IO (Ptr Word8)
    c_PQunescapeBytea CString
    from Ptr CSize
    to_length
              if to == nullPtr
                then return Nothing
                else do tofp <- newForeignPtr p_PQfreemem to
                        l <- peek to_length
                        return $! Just $! B.fromForeignPtr tofp 0 $ fromIntegral l

    -- | @escapeIdentifier@ escapes a string for use as an SQL identifier, such
    --   as a table, column, or function name. This is useful when a user-supplied
    --   identifier might contain special characters that would otherwise not be
    --   interpreted as part of the identifier by the SQL parser, or when the
    --   identifier might contain upper case characters whose case should be
    --   preserved.
    --
    --   The return string has all special characters replaced so that it will
    --   be properly processed as an SQL identifier. The return string will also
    --   be surrounded by double quotes.
    --
    --   On error, @escapeIdentifier@ returns 'Nothing' and a suitable message
    --   is stored in the conn object.

    escapeIdentifier :: Connection
                     -> B.ByteString
                     -> IO (Maybe B.ByteString)
    escapeIdentifier :: Connection -> ByteString -> IO (Maybe ByteString)
    escapeIdentifier Connection
    connection ByteString
    bs =
      Connection
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    conn ->
        ByteString
    -> (CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
    B.unsafeUseAsCStringLen ByteString
    bs ((CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (CStringLen -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \(CString
    from, Int
    bslen) -> IO (Maybe ByteString) -> IO (Maybe ByteString)
    forall a. IO a -> IO a
    mask_ (IO (Maybe ByteString) -> IO (Maybe ByteString))
    -> IO (Maybe ByteString) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ do
          bs'ptr <- Ptr PGconn -> CString -> CSize -> IO CString
    c_PQescapeIdentifier Ptr PGconn
    conn CString
    from (Int -> CSize
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    bslen)
          if bs'ptr == nullPtr
            then return Nothing
            else do
                bs' <- B.packCString bs'ptr
                c_PQfreemem bs'ptr
                return $ Just bs'

    -- $copy
    --
    -- This provides support for PostgreSQL's @COPY FROM@ facility.
    --
    -- For more information, see:
    --
    --  * <http://www.postgresql.org/docs/current/static/sql-copy.html>
    --
    --  * <http://www.postgresql.org/docs/current/static/libpq-copy.html>
    --

    data CopyInResult
       = CopyInOk          -- ^ The data was sent.
       | CopyInError       -- ^ An error occurred (use 'errorMessage'
                           --   to retrieve details).
       | CopyInWouldBlock  -- ^ The data was not sent because the
                           --   attempt would block (this case is only
                           --   possible if the connection is in
                           --   nonblocking mode)  Wait for
                           --   write-ready (e.g. by using
                           --   'Control.Concurrent.threadWaitWrite'
                           --   on the 'socket') and try again.
         deriving (CopyInResult -> CopyInResult -> Bool
    (CopyInResult -> CopyInResult -> Bool)
    -> (CopyInResult -> CopyInResult -> Bool) -> Eq CopyInResult
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: CopyInResult -> CopyInResult -> Bool
    == :: CopyInResult -> CopyInResult -> Bool
    $c/= :: CopyInResult -> CopyInResult -> Bool
    /= :: CopyInResult -> CopyInResult -> Bool
    Eq, Int -> CopyInResult -> [Char] -> [Char]
    [CopyInResult] -> [Char] -> [Char]
    CopyInResult -> [Char]
    (Int -> CopyInResult -> [Char] -> [Char])
    -> (CopyInResult -> [Char])
    -> ([CopyInResult] -> [Char] -> [Char])
    -> Show CopyInResult
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> CopyInResult -> [Char] -> [Char]
    showsPrec :: Int -> CopyInResult -> [Char] -> [Char]
    $cshow :: CopyInResult -> [Char]
    show :: CopyInResult -> [Char]
    $cshowList :: [CopyInResult] -> [Char] -> [Char]
    showList :: [CopyInResult] -> [Char] -> [Char]
    Show)

    toCopyInResult :: CInt -> IO CopyInResult
    toCopyInResult :: CInt -> IO CopyInResult
    toCopyInResult CInt
    n | CInt
    n CInt -> CInt -> Bool
    forall a. Ord a => a -> a -> Bool
    < CInt
    0     = CopyInResult -> IO CopyInResult
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return CopyInResult
    CopyInError
                     | CInt
    n CInt -> CInt -> Bool
    forall a. Eq a => a -> a -> Bool
    == CInt
    0    = CopyInResult -> IO CopyInResult
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return CopyInResult
    CopyInWouldBlock
                     | Bool
    otherwise = CopyInResult -> IO CopyInResult
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return CopyInResult
    CopyInOk

    -- | Send raw @COPY@ data to the server during the 'CopyIn' state.
    putCopyData :: Connection -> B.ByteString -> IO CopyInResult
    putCopyData :: Connection -> ByteString -> IO CopyInResult
    putCopyData Connection
    conn ByteString
    bs =
        ByteString -> (CStringLen -> IO CopyInResult) -> IO CopyInResult
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
    B.unsafeUseAsCStringLen ByteString
    bs ((CStringLen -> IO CopyInResult) -> IO CopyInResult)
    -> (CStringLen -> IO CopyInResult) -> IO CopyInResult
    forall a b. (a -> b) -> a -> b
    $ Connection -> CStringLen -> IO CopyInResult
    putCopyCString Connection
    conn

    putCopyCString :: Connection -> CStringLen -> IO CopyInResult
    putCopyCString :: Connection -> CStringLen -> IO CopyInResult
    putCopyCString Connection
    conn (CString
    str, Int
    len) =
        CInt -> IO CopyInResult
    toCopyInResult (CInt -> IO CopyInResult) -> IO CInt -> IO CopyInResult
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<<
            (Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    conn ((Ptr PGconn -> IO CInt) -> IO CInt)
    -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    ptr -> Ptr PGconn -> CString -> CInt -> IO CInt
    c_PQputCopyData Ptr PGconn
    ptr CString
    str (Int -> CInt
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    len))

    -- | Send end-of-data indication to the server during the 'CopyIn' state.
    --
    --  * @putCopyEnd conn Nothing@ ends the 'CopyIn' operation successfully.
    --
    --  * @putCopyEnd conn (Just errormsg)@ forces the @COPY@ to fail, with
    --    @errormsg@ used as the error message.
    --
    -- After 'putCopyEnd' returns 'CopyOk', call 'getResult' to obtain the final
    -- result status of the @COPY@ command.  Then return to normal operation.
    putCopyEnd :: Connection -> Maybe B.ByteString -> IO CopyInResult
    putCopyEnd :: Connection -> Maybe ByteString -> IO CopyInResult
    putCopyEnd Connection
    conn Maybe ByteString
    Nothing =
        CInt -> IO CopyInResult
    toCopyInResult (CInt -> IO CopyInResult) -> IO CInt -> IO CopyInResult
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<<
            (Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    conn ((Ptr PGconn -> IO CInt) -> IO CInt)
    -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    ptr -> Ptr PGconn -> CString -> IO CInt
    c_PQputCopyEnd Ptr PGconn
    ptr CString
    forall a. Ptr a
    nullPtr)
    putCopyEnd Connection
    conn (Just ByteString
    errormsg) =
        CInt -> IO CopyInResult
    toCopyInResult (CInt -> IO CopyInResult) -> IO CInt -> IO CopyInResult
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<<
            (ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    errormsg ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    errormsg_cstr ->
                Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    conn ((Ptr PGconn -> IO CInt) -> IO CInt)
    -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    ptr -> Ptr PGconn -> CString -> IO CInt
    c_PQputCopyEnd Ptr PGconn
    ptr CString
    errormsg_cstr)

    data CopyOutResult
       = CopyOutRow !B.ByteString -- ^ Data representing a single row of the result
       | CopyOutWouldBlock        -- ^ A complete row is not yet available.  This
                                  --   case is only possible when 'getCopyData' is
                                  --   has the async parameter set to 'True'.
       | CopyOutDone              -- ^ No more rows are available
       | CopyOutError             -- ^ An error occurred (e.g. the connection is
                                  --   not in the 'CopyOut' state).  Call
                                  --   'errorMessage' for more information.
         deriving Int -> CopyOutResult -> [Char] -> [Char]
    [CopyOutResult] -> [Char] -> [Char]
    CopyOutResult -> [Char]
    (Int -> CopyOutResult -> [Char] -> [Char])
    -> (CopyOutResult -> [Char])
    -> ([CopyOutResult] -> [Char] -> [Char])
    -> Show CopyOutResult
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> CopyOutResult -> [Char] -> [Char]
    showsPrec :: Int -> CopyOutResult -> [Char] -> [Char]
    $cshow :: CopyOutResult -> [Char]
    show :: CopyOutResult -> [Char]
    $cshowList :: [CopyOutResult] -> [Char] -> [Char]
    showList :: [CopyOutResult] -> [Char] -> [Char]
    Show

    -- | Receive raw @COPY@ data from the server during the 'CopyOut' state.
    --   The boolean parameter determines whether or not the call will block
    --   while waiting for data.
    getCopyData :: Connection -> Bool -> IO CopyOutResult
    getCopyData :: Connection -> Bool -> IO CopyOutResult
    getCopyData Connection
    conn Bool
    async = (Ptr (Ptr Word8) -> IO CopyOutResult) -> IO CopyOutResult
    forall a b. Storable a => (Ptr a -> IO b) -> IO b
    alloca ((Ptr (Ptr Word8) -> IO CopyOutResult) -> IO CopyOutResult)
    -> (Ptr (Ptr Word8) -> IO CopyOutResult) -> IO CopyOutResult
    forall a b. (a -> b) -> a -> b
    $ \Ptr (Ptr Word8)
    strp -> Connection -> (Ptr PGconn -> IO CopyOutResult) -> IO CopyOutResult
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    conn ((Ptr PGconn -> IO CopyOutResult) -> IO CopyOutResult)
    -> (Ptr PGconn -> IO CopyOutResult) -> IO CopyOutResult
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
        len <- Ptr PGconn -> Ptr (Ptr Word8) -> CInt -> IO CInt
    c_PQgetCopyData Ptr PGconn
    c Ptr (Ptr Word8)
    strp (CInt -> IO CInt) -> CInt -> IO CInt
    forall a b. (a -> b) -> a -> b
    $! Bool -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Bool
    async
        if len <= 0
          then case compare len (-1) of
                 Ordering
    LT -> CopyOutResult -> IO CopyOutResult
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return CopyOutResult
    CopyOutError
                 Ordering
    EQ -> CopyOutResult -> IO CopyOutResult
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return CopyOutResult
    CopyOutDone
                 Ordering
    GT -> CopyOutResult -> IO CopyOutResult
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return CopyOutResult
    CopyOutWouldBlock
          else do
            fp <- newForeignPtr p_PQfreemem =<< peek strp
            return $! CopyOutRow (B.fromForeignPtr fp 0 (fromIntegral len))

    -- $asynccommand
    -- The 'exec' function is adequate for submitting commands in normal,
    -- synchronous applications. It has a couple of deficiencies, however,
    -- that can be of importance to some users:
    --
    --   * 'exec' waits for the command to be completed. The application
    --   might have other work to do (such as maintaining a user
    --   interface), in which case it won't want to block waiting for the
    --   response.
    --
    --   * Since the execution of the client application is suspended
    --   while it waits for the result, it is hard for the application to
    --   decide that it would like to try to cancel the ongoing
    --   command. (It can be done from a signal handler, but not
    --   otherwise.)
    --
    --   * 'exec' can return only one 'Result'. If the submitted command
    --   string contains multiple SQL commands, all but the last 'Result'
    --   are discarded by 'exec'.
    --
    -- Applications that do not like these limitations can instead use the
    -- underlying functions that 'exec' is built from: 'sendQuery' and
    -- 'getResult'. There are also 'sendQueryParams', 'sendPrepare',
    -- 'sendQueryPrepared', 'sendDescribePrepared', and
    -- 'sendDescribePortal', which can be used with 'getResult' to
    -- duplicate the functionality of 'execParams', 'prepare',
    -- 'execPrepared', 'describePrepared', and 'describePortal'
    -- respectively.

    -- | Submits a command to the server without waiting for the
    -- result(s). 'True' is returned if the command was successfully
    -- dispatched and 'False' if not (in which case, use 'errorMessage' to
    -- get more information about the failure).
    sendQuery :: Connection
              -> B.ByteString
              -> IO Bool
    sendQuery :: Connection -> ByteString -> IO Bool
    sendQuery Connection
    connection ByteString
    query =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO Bool)
    -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    p ->
            ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    query ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ Ptr PGconn -> CString -> IO CInt
    c_PQsendQuery Ptr PGconn
    p

    -- | Submits a command and separate parameters to the server without
    -- waiting for the result(s).
    sendQueryParams :: Connection
                    -> B.ByteString
                    -> [Maybe (Oid, B.ByteString, Format)]
                    -> Format
                    -> IO Bool
    sendQueryParams :: Connection
    -> ByteString
    -> [Maybe (Oid, ByteString, Format)]
    -> Format
    -> IO Bool
    sendQueryParams Connection
    connection ByteString
    statement [Maybe (Oid, ByteString, Format)]
    params Format
    rFmt =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO Bool)
    -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    statement ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                [Maybe (Oid, ByteString, Format)]
    -> (CInt
        -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO CInt)
    -> IO CInt
    forall a.
    [Maybe (Oid, ByteString, Format)]
    -> (CInt -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a)
    -> IO a
    withParams [Maybe (Oid, ByteString, Format)]
    params ((CInt
      -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO CInt)
     -> IO CInt)
    -> (CInt
        -> Ptr Oid -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO CInt)
    -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CInt
    n Ptr Oid
    ts Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs ->
                    Ptr PGconn
    -> CString
    -> CInt
    -> Ptr Oid
    -> Ptr CString
    -> Ptr CInt
    -> Ptr CInt
    -> CInt
    -> IO CInt
    c_PQsendQueryParams Ptr PGconn
    c CString
    s CInt
    n Ptr Oid
    ts Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs CInt
    f

        where
          !f :: CInt
    f = Format -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Format
    rFmt

    -- | Sends a request to create a prepared statement with the given
    -- parameters, without waiting for completion.
    sendPrepare :: Connection
                -> B.ByteString
                -> B.ByteString
                -> Maybe [Oid]
                -> IO Bool
    sendPrepare :: Connection -> ByteString -> ByteString -> Maybe [Oid] -> IO Bool
    sendPrepare Connection
    connection ByteString
    stmtName ByteString
    query Maybe [Oid]
    mParamTypes =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO Bool)
    -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    stmtName ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    query ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    q ->
                    ([Oid] -> (Int -> Ptr Oid -> IO CInt) -> IO CInt)
    -> Maybe [Oid] -> (Int -> Ptr Oid -> IO CInt) -> IO CInt
    forall a b c.
    (a -> (Int -> Ptr b -> IO c) -> IO c)
    -> Maybe a -> (Int -> Ptr b -> IO c) -> IO c
    maybeWithInt [Oid] -> (Int -> Ptr Oid -> IO CInt) -> IO CInt
    forall a b. Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
    withArrayLen Maybe [Oid]
    mParamTypes ((Int -> Ptr Oid -> IO CInt) -> IO CInt)
    -> (Int -> Ptr Oid -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Int
    l Ptr Oid
    o ->
                        Ptr PGconn -> CString -> CString -> CInt -> Ptr Oid -> IO CInt
    c_PQsendPrepare Ptr PGconn
    c CString
    s CString
    q (Int -> CInt
    intToCInt Int
    l) Ptr Oid
    o

    -- | Sends a request to execute a prepared statement with given
    -- parameters, without waiting for the result(s).
    sendQueryPrepared :: Connection
                      -> B.ByteString
                      -> [Maybe (B.ByteString, Format)]
                      -> Format
                      -> IO Bool
    sendQueryPrepared :: Connection
    -> ByteString -> [Maybe (ByteString, Format)] -> Format -> IO Bool
    sendQueryPrepared Connection
    connection ByteString
    stmtName [Maybe (ByteString, Format)]
    params Format
    rFmt =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO Bool)
    -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    stmtName ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                [Maybe (ByteString, Format)]
    -> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO CInt)
    -> IO CInt
    forall a.
    [Maybe (ByteString, Format)]
    -> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a) -> IO a
    withParamsPrepared [Maybe (ByteString, Format)]
    params ((CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO CInt)
     -> IO CInt)
    -> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO CInt)
    -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CInt
    n Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs ->
                    Ptr PGconn
    -> CString
    -> CInt
    -> Ptr CString
    -> Ptr CInt
    -> Ptr CInt
    -> CInt
    -> IO CInt
    c_PQsendQueryPrepared Ptr PGconn
    c CString
    s CInt
    n Ptr CString
    vs Ptr CInt
    ls Ptr CInt
    fs CInt
    f

        where
          !f :: CInt
    f = Format -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Format
    rFmt

    -- | Submits a request to obtain information about the specified
    -- prepared statement, without waiting for completion.
    --
    -- This is an asynchronous version of 'describePrepared': it returns
    -- 'True' if it was able to dispatch the request, and 'False' if
    -- not. After a successful call, call 'getResult' to obtain the
    -- results. The function's parameters are handled identically to
    -- 'describePrepared'. Like 'describePrepared', it will not work on
    -- 2.0-protocol connections.
    sendDescribePrepared :: Connection
                         -> B.ByteString -- ^ stmtName
                         -> IO Bool
    sendDescribePrepared :: Connection -> ByteString -> IO Bool
    sendDescribePrepared Connection
    connection ByteString
    stmtName =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO Bool)
    -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    stmtName ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                Ptr PGconn -> CString -> IO CInt
    c_PQsendDescribePrepared Ptr PGconn
    c CString
    s

    -- | Submits a request to obtain information about the specified
    -- portal, without waiting for completion.
    --
    -- This is an asynchronous version of 'describePortal': it returns
    -- 'True' if it was able to dispatch the request, and 'False' if
    -- not. After a successful call, call 'getResult' to obtain the
    -- results. The function's parameters are handled identically to
    -- 'describePortal'. Like 'describePortal', it will not work on
    -- 2.0-protocol connections.
    sendDescribePortal :: Connection
                         -> B.ByteString -- ^ portalName
                         -> IO Bool
    sendDescribePortal :: Connection -> ByteString -> IO Bool
    sendDescribePortal Connection
    connection ByteString
    portalName =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO Bool)
    -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
            ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    portalName ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    p ->
                Ptr PGconn -> CString -> IO CInt
    c_PQsendDescribePortal Ptr PGconn
    c CString
    p

    -- | Waits for the next result from a prior 'sendQuery',
    -- 'sendQueryParams', 'sendPrepare', or 'sendQueryPrepared' call, and
    -- returns it. A null pointer is returned when the command is complete
    -- and there will be no more results.
    getResult :: Connection
              -> IO (Maybe Result)
    getResult :: Connection -> IO (Maybe Result)
    getResult Connection
    connection =
        do resPtr <- Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO (Ptr PGresult)
    c_PQgetResult
           if resPtr == nullPtr
               then return Nothing
               else (Just . Result) `fmap` newForeignPtr p_PQclear resPtr

    -- | If input is available from the server, consume it.
    --
    -- 'consumeInput' normally returns 'True' indicating "no error", but
    -- returns 'False' if there was some kind of trouble (in which case
    -- 'errorMessage' can be consulted). Note that the result does not say
    -- whether any input data was actually collected. After calling
    -- 'consumeInput', the application can check 'isBusy' and/or
    -- 'notifies' to see if their state has changed.
    consumeInput :: Connection
                 -> IO Bool
    consumeInput :: Connection -> IO Bool
    consumeInput Connection
    connection = Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQconsumeInput

    -- | Returns True if a command is busy, that is, getResult would block
    -- waiting for input. A False return indicates that getResult can be
    -- called with assurance of not blocking.
    --
    -- 'isBusy' will not itself attempt to read data from the server;
    -- therefore 'consumeInput' must be invoked first, or the busy state
    -- will never end.
    isBusy :: Connection
           -> IO Bool
    isBusy :: Connection -> IO Bool
    isBusy Connection
    connection = Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQisBusy

    -- | Sets the nonblocking status of the connection.
    setnonblocking :: Connection
                   -> Bool
                   -> IO Bool
    setnonblocking :: Connection -> Bool -> IO Bool
    setnonblocking Connection
    connection Bool
    blocking = do
           stat <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO CInt)
    -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    ptr -> Ptr PGconn -> CInt -> IO CInt
    c_PQsetnonblocking Ptr PGconn
    ptr (Bool -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Bool
    blocking)
           return $! stat == 0

    -- | Returns the blocking status of the database connection.
    isnonblocking :: Connection
                  -> IO Bool
    isnonblocking :: Connection -> IO Bool
    isnonblocking Connection
    connection = Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQisnonblocking

    -- | Select single-row mode for the currently-executing query.
    --
    -- This function can only be called immediately after PQsendQuery or one of its
    -- sibling functions, before any other operation on the connection such as
    -- PQconsumeInput or PQgetResult. If called at the correct time, the function
    -- activates single-row mode for the current query and returns 1. Otherwise the
    -- mode stays unchanged and the function returns 0. In any case, the mode
    -- reverts to normal after completion of the current query.
    setSingleRowMode :: Connection
                     -> IO Bool
    setSingleRowMode :: Connection -> IO Bool
    setSingleRowMode Connection
    connection = Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQsetSingleRowMode

    data FlushStatus = FlushOk
                     | FlushFailed
                     | FlushWriting
                       deriving (FlushStatus -> FlushStatus -> Bool
    (FlushStatus -> FlushStatus -> Bool)
    -> (FlushStatus -> FlushStatus -> Bool) -> Eq FlushStatus
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: FlushStatus -> FlushStatus -> Bool
    == :: FlushStatus -> FlushStatus -> Bool
    $c/= :: FlushStatus -> FlushStatus -> Bool
    /= :: FlushStatus -> FlushStatus -> Bool
    Eq, Int -> FlushStatus -> [Char] -> [Char]
    [FlushStatus] -> [Char] -> [Char]
    FlushStatus -> [Char]
    (Int -> FlushStatus -> [Char] -> [Char])
    -> (FlushStatus -> [Char])
    -> ([FlushStatus] -> [Char] -> [Char])
    -> Show FlushStatus
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> FlushStatus -> [Char] -> [Char]
    showsPrec :: Int -> FlushStatus -> [Char] -> [Char]
    $cshow :: FlushStatus -> [Char]
    show :: FlushStatus -> [Char]
    $cshowList :: [FlushStatus] -> [Char] -> [Char]
    showList :: [FlushStatus] -> [Char] -> [Char]
    Show)

    -- | Attempts to flush any queued output data to the server. Returns
    -- 'FlushOk' if successful (or if the send queue is empty),
    -- 'FlushFailed' if it failed for some reason, or 'FlushWriting' if it
    -- was unable to send all the data in the send queue yet (this case
    -- can only occur if the connection is nonblocking).
    flush :: Connection
          -> IO FlushStatus
    flush :: Connection -> IO FlushStatus
    flush Connection
    connection =
        do stat <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQflush
           case stat of
             CInt
    0 -> FlushStatus -> IO FlushStatus
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return FlushStatus
    FlushOk
             CInt
    1 -> FlushStatus -> IO FlushStatus
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return FlushStatus
    FlushWriting
             CInt
    _ -> FlushStatus -> IO FlushStatus
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return FlushStatus
    FlushFailed

    -- $pipelinemode
    -- These functions control behaviour in pipeline mode.
    --
    -- Pipeline mode allows applications to send a query
    -- without having to read the result of the previously
    -- sent query. Taking advantage of the pipeline mode,
    -- a client will wait less for the server, since multiple
    -- queries/results can be sent/received in
    -- a single network transaction.

    -- | Returns the current pipeline mode status of the libpq connection.
    --
    -- @since 0.11.0.0
    pipelineStatus :: Connection
                   -> IO PipelineStatus
    pipelineStatus :: Connection -> IO PipelineStatus
    pipelineStatus Connection
    connection = do
        stat <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQpipelineStatus
        maybe
          (fail $ "Unknown pipeline status " ++ show stat)
          return
          (fromCInt stat)

    -- | Causes a connection to enter pipeline mode if it is currently idle or already in pipeline mode.
    --
    -- @since 0.11.0.0
    enterPipelineMode :: Connection
                      -> IO Bool
    enterPipelineMode :: Connection -> IO Bool
    enterPipelineMode Connection
    connection =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQenterPipelineMode

    -- | Causes a connection to exit pipeline mode if it is currently in pipeline mode with an empty queue and no pending results.
    --
    -- @since 0.11.0.0
    exitPipelineMode :: Connection
                     -> IO Bool
    exitPipelineMode :: Connection -> IO Bool
    exitPipelineMode Connection
    connection =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQexitPipelineMode

    -- | Marks a synchronization point in a pipeline by sending a sync message and flushing the send buffer. This serves as the delimiter of an implicit transaction and an error recovery point>
    --
    -- @since 0.11.0.0
    pipelineSync :: Connection
                 -> IO Bool
    pipelineSync :: Connection -> IO Bool
    pipelineSync Connection
    connection =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQpipelineSync

    -- | Sends a request for the server to flush its output buffer.
    --
    -- @since 0.11.0.0
    sendFlushRequest :: Connection
                     -> IO Bool
    sendFlushRequest :: Connection -> IO Bool
    sendFlushRequest Connection
    connection =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Bool
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    c_PQsendFlushRequest

    -- $cancel
    -- A client application can request cancellation of a command that is
    -- still being processed by the server, using the functions described
    -- in this section.

    -- | Contains the information needed to cancel a command issued
    -- through a particular database connection.
    newtype Cancel = Cancel (ForeignPtr PGcancel) deriving (Cancel -> Cancel -> Bool
    (Cancel -> Cancel -> Bool)
    -> (Cancel -> Cancel -> Bool) -> Eq Cancel
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: Cancel -> Cancel -> Bool
    == :: Cancel -> Cancel -> Bool
    $c/= :: Cancel -> Cancel -> Bool
    /= :: Cancel -> Cancel -> Bool
    Eq, Int -> Cancel -> [Char] -> [Char]
    [Cancel] -> [Char] -> [Char]
    Cancel -> [Char]
    (Int -> Cancel -> [Char] -> [Char])
    -> (Cancel -> [Char])
    -> ([Cancel] -> [Char] -> [Char])
    -> Show Cancel
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> Cancel -> [Char] -> [Char]
    showsPrec :: Int -> Cancel -> [Char] -> [Char]
    $cshow :: Cancel -> [Char]
    show :: Cancel -> [Char]
    $cshowList :: [Cancel] -> [Char] -> [Char]
    showList :: [Cancel] -> [Char] -> [Char]
    Show)

    -- | Creates a data structure containing the information needed to
    -- cancel a command issued through a particular database connection.
    --
    -- 'getCancel' creates a 'Cancel' object given a 'Connection'. It will
    -- return 'Nothing' if the given conn is an invalid connection.

    getCancel :: Connection
              -> IO (Maybe Cancel)
    getCancel :: Connection -> IO (Maybe Cancel)
    getCancel Connection
    connection =
        IO (Maybe Cancel) -> IO (Maybe Cancel)
    forall a. IO a -> IO a
    mask_ (IO (Maybe Cancel) -> IO (Maybe Cancel))
    -> IO (Maybe Cancel) -> IO (Maybe Cancel)
    forall a b. (a -> b) -> a -> b
    $ Connection
    -> (Ptr PGconn -> IO (Maybe Cancel)) -> IO (Maybe Cancel)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Cancel)) -> IO (Maybe Cancel))
    -> (Ptr PGconn -> IO (Maybe Cancel)) -> IO (Maybe Cancel)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    conn ->
            do ptr <- Ptr PGconn -> IO (Ptr PGcancel)
    c_PQgetCancel Ptr PGconn
    conn
               if ptr == nullPtr
                 then return Nothing
                 else do fp <- newForeignPtr p_PQfreeCancel ptr
                         return $ Just $ Cancel fp

    -- | Requests that the server abandon processing of the current
    -- command.
    --
    -- The return value is 'Right ()' if the cancel request was
    -- successfully dispatched and if not, 'Left B.ByteString' containing
    -- an error message explaining why not.
    --
    -- Successful dispatch is no guarantee that the request will have any
    -- effect, however. If the cancellation is effective, the current
    -- command will terminate early and return an error result. If the
    -- cancellation fails (say, because the server was already done
    -- processing the command), then there will be no visible result at
    -- all.
    cancel :: Cancel
           -> IO (Either B.ByteString ())
    cancel :: Cancel -> IO (Either ByteString ())
    cancel (Cancel ForeignPtr PGcancel
    fp) =
        ForeignPtr PGcancel
    -> (Ptr PGcancel -> IO (Either ByteString ()))
    -> IO (Either ByteString ())
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
    withForeignPtr ForeignPtr PGcancel
    fp ((Ptr PGcancel -> IO (Either ByteString ()))
     -> IO (Either ByteString ()))
    -> (Ptr PGcancel -> IO (Either ByteString ()))
    -> IO (Either ByteString ())
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGcancel
    ptr -> do
            Int
    -> (CString -> IO (Either ByteString ()))
    -> IO (Either ByteString ())
    forall a b. Int -> (Ptr a -> IO b) -> IO b
    allocaBytes Int
    errbufsize ((CString -> IO (Either ByteString ()))
     -> IO (Either ByteString ()))
    -> (CString -> IO (Either ByteString ()))
    -> IO (Either ByteString ())
    forall a b. (a -> b) -> a -> b
    $ \CString
    errbuf -> do
                res <- Ptr PGcancel -> CString -> CInt -> IO CInt
    c_PQcancel Ptr PGcancel
    ptr CString
    errbuf (CInt -> IO CInt) -> CInt -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ Int -> CInt
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    errbufsize
                case res of
                  CInt
    1 -> Either ByteString () -> IO (Either ByteString ())
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Either ByteString () -> IO (Either ByteString ()))
    -> Either ByteString () -> IO (Either ByteString ())
    forall a b. (a -> b) -> a -> b
    $ () -> Either ByteString ()
    forall a b. b -> Either a b
    Right ()
                  CInt
    _ -> ByteString -> Either ByteString ()
    forall a b. a -> Either a b
    Left (ByteString -> Either ByteString ())
    -> IO ByteString -> IO (Either ByteString ())
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    `fmap` CString -> IO ByteString
    B.packCString CString
    errbuf
        where
          errbufsize :: Int
    errbufsize = Int
    256

    -- $asyncnotification
    -- PostgreSQL offers asynchronous notification via the LISTEN and
    -- NOTIFY commands. A client session registers its interest in a
    -- particular notification channel with the LISTEN command (and can
    -- stop listening with the UNLISTEN command). All sessions listening
    -- on a particular channel will be notified asynchronously when a
    -- NOTIFY command with that channel name is executed by any session. A
    -- \"payload\" string can be passed to communicate additional data to
    -- the listeners.
    --
    -- libpq applications submit LISTEN, UNLISTEN, and NOTIFY commands as
    -- ordinary SQL commands. The arrival of NOTIFY messages can
    -- subsequently be detected by calling 'notifies'.

    -- | Returns the next notification from a list of unhandled
    -- notification messages received from the server. It returns a
    -- 'Nothing' if there are no pending notifications. Once a
    -- notification is returned from notifies, it is considered handled
    -- and will be removed from the list of notifications.
    notifies :: Connection
             -> IO (Maybe Notify)
    notifies :: Connection -> IO (Maybe Notify)
    notifies Connection
    connection =
        Connection
    -> (Ptr PGconn -> IO (Maybe Notify)) -> IO (Maybe Notify)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Notify)) -> IO (Maybe Notify))
    -> (Ptr PGconn -> IO (Maybe Notify)) -> IO (Maybe Notify)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    ptr ->
            do mn <- Ptr PGconn -> IO (Ptr Notify)
    c_PQnotifies Ptr PGconn
    ptr
               if mn == nullPtr
                 then return Nothing
                 else do
                         result <- Just `fmap` peek mn
                         c_PQfreemem mn
                         return result

    -- $control
    -- These functions control miscellaneous details of libpq's behavior.

    -- | Returns the client encoding.
    clientEncoding :: Connection
                   -> IO B.ByteString
    clientEncoding :: Connection -> IO ByteString
    clientEncoding Connection
    connection =
        Connection -> (Ptr PGconn -> IO ByteString) -> IO ByteString
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO ByteString) -> IO ByteString)
    -> (Ptr PGconn -> IO ByteString) -> IO ByteString
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    ptr ->
            do i <- Ptr PGconn -> IO CInt
    c_PQclientEncoding Ptr PGconn
    ptr
               cstr <- c_pg_encoding_to_char i
               len <- B.c_strlen cstr
               fp <- newForeignPtr_ $ castPtr cstr
               return $ B.fromForeignPtr fp 0 $ fromIntegral len

    -- | Sets the client encoding.
    setClientEncoding :: Connection -> B.ByteString -> IO Bool
    setClientEncoding :: Connection -> ByteString -> IO Bool
    setClientEncoding Connection
    connection ByteString
    enc =
        do stat <- Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO CInt)
    -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c ->
                   ByteString -> (CString -> IO CInt) -> IO CInt
    forall a. ByteString -> (CString -> IO a) -> IO a
    B.useAsCString ByteString
    enc ((CString -> IO CInt) -> IO CInt)
    -> (CString -> IO CInt) -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ \CString
    s ->
                       Ptr PGconn -> CString -> IO CInt
    c_PQsetClientEncoding Ptr PGconn
    c CString
    s

           return $! stat == 0

    -- | Determines the verbosity of messages returned by 'errorMessage'
    -- and 'resultErrorMessage'.
    --
    -- 'setErrorVerbosity' sets the verbosity mode, returning the
    -- connection's previous setting. In 'ErrorsTerse' mode, returned
    -- messages include severity, primary text, and position only; this
    -- will normally fit on a single line. The default mode produces
    -- messages that include the above plus any detail, hint, or context
    -- fields (these might span multiple lines). The 'ErrorsVerbose' mode
    -- includes all available fields. Changing the verbosity does not
    -- affect the messages available from already-existing 'Result'
    -- objects, only subsequently-created ones.
    setErrorVerbosity :: Connection
                      -> Verbosity
                      -> IO Verbosity
    setErrorVerbosity :: Connection -> Verbosity -> IO Verbosity
    setErrorVerbosity Connection
    connection Verbosity
    verbosity =
        Connection -> (Ptr PGconn -> IO CInt) -> IO Verbosity
    forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection ((Ptr PGconn -> IO CInt) -> IO Verbosity)
    -> (Ptr PGconn -> IO CInt) -> IO Verbosity
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    p ->
            Ptr PGconn -> CInt -> IO CInt
    c_PQsetErrorVerbosity Ptr PGconn
    p (CInt -> IO CInt) -> CInt -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ Verbosity -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt Verbosity
    verbosity

    enumFromConn :: FromCInt b
                 => Connection
                 -> (Ptr PGconn -> IO CInt)
                 -> IO b
    enumFromConn :: forall b.
    FromCInt b =>
    Connection -> (Ptr PGconn -> IO CInt) -> IO b
    enumFromConn Connection
    connection Ptr PGconn -> IO CInt
    f = Connection -> (Ptr PGconn -> IO CInt) -> IO CInt
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO CInt
    f IO CInt -> (CInt -> IO b) -> IO b
    forall a b. IO a -> (a -> IO b) -> IO b
    forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
    >>= IO b -> (b -> IO b) -> Maybe b -> IO b
    forall b a. b -> (a -> b) -> Maybe a -> b
    maybe ([Char] -> IO b
    forall a. [Char] -> IO a
    forall (m :: * -> *) a. MonadFail m => [Char] -> m a
    fail [Char]
    "enumFromConn") b -> IO b
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Maybe b -> IO b) -> (CInt -> Maybe b) -> CInt -> IO b
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . CInt -> Maybe b
    forall a. FromCInt a => CInt -> Maybe a
    fromCInt

    resultFromConn :: Connection
                   -> (Ptr PGconn -> IO (Ptr PGresult))
                   -> IO (Maybe Result)
    resultFromConn :: Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Maybe Result)
    resultFromConn Connection
    connection Ptr PGconn -> IO (Ptr PGresult)
    f =
        IO (Maybe Result) -> IO (Maybe Result)
    forall a. IO a -> IO a
    mask_ (IO (Maybe Result) -> IO (Maybe Result))
    -> IO (Maybe Result) -> IO (Maybe Result)
    forall a b. (a -> b) -> a -> b
    $ do
           resPtr <- Connection
    -> (Ptr PGconn -> IO (Ptr PGresult)) -> IO (Ptr PGresult)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection Ptr PGconn -> IO (Ptr PGresult)
    f
           if resPtr == nullPtr
               then return Nothing
               else (Just . Result) `fmap` newForeignPtr p_PQclear resPtr

    withResult :: Result
               -> (Ptr PGresult -> IO b)
               -> IO b
    withResult :: forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult (Result ForeignPtr PGresult
    fp) Ptr PGresult -> IO b
    f = ForeignPtr PGresult -> (Ptr PGresult -> IO b) -> IO b
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
    withForeignPtr ForeignPtr PGresult
    fp Ptr PGresult -> IO b
    f

    numFromResult :: (Integral a, Num b) => Result
                  -> (Ptr PGresult -> IO a)
                  -> IO b
    numFromResult :: forall a b.
    (Integral a, Num b) =>
    Result -> (Ptr PGresult -> IO a) -> IO b
    numFromResult Result
    result Ptr PGresult -> IO a
    f = (a -> b) -> IO a -> IO b
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap a -> b
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (IO a -> IO b) -> IO a -> IO b
    forall a b. (a -> b) -> a -> b
    $ Result -> (Ptr PGresult -> IO a) -> IO a
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    result Ptr PGresult -> IO a
    f

    enumFromResult :: FromCInt b
                   => Result
                   -> (Ptr PGresult -> IO CInt)
                   -> IO b
    enumFromResult :: forall b. FromCInt b => Result -> (Ptr PGresult -> IO CInt) -> IO b
    enumFromResult Result
    result Ptr PGresult -> IO CInt
    f = Result -> (Ptr PGresult -> IO CInt) -> IO CInt
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
    withResult Result
    result Ptr PGresult -> IO CInt
    f IO CInt -> (CInt -> IO b) -> IO b
    forall a b. IO a -> (a -> IO b) -> IO b
    forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
    >>= IO b -> (b -> IO b) -> Maybe b -> IO b
    forall b a. b -> (a -> b) -> Maybe a -> b
    maybe ([Char] -> IO b
    forall a. [Char] -> IO a
    forall (m :: * -> *) a. MonadFail m => [Char] -> m a
    fail [Char]
    "enumFromResult") b -> IO b
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Maybe b -> IO b) -> (CInt -> Maybe b) -> CInt -> IO b
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . CInt -> Maybe b
    forall a. FromCInt a => CInt -> Maybe a
    fromCInt

    -- | Returns a ByteString with a finalizer that touches the ForeignPtr
    -- PGresult that \"owns\" the CString to keep it alive.
    --
    -- The CString must be a null terminated c string. nullPtrs are
    -- treated as 'Nothing'.
    maybeBsFromResult :: Result
                      -> (Ptr PGresult -> IO CString)
                      -> IO (Maybe B.ByteString)
    maybeBsFromResult :: Result -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromResult (Result ForeignPtr PGresult
    res) Ptr PGresult -> IO CString
    f = ForeignPtr PGresult
    -> (Ptr PGresult -> IO CString) -> IO (Maybe ByteString)
    forall a.
    ForeignPtr a -> (Ptr a -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromForeignPtr ForeignPtr PGresult
    res Ptr PGresult -> IO CString
    f

    -- | Returns a ByteString with a finalizer that touches the ForeignPtr
    -- that \"owns\" the CString to keep it alive.
    --
    -- The CString must be a null terminated c string. nullPtrs are
    -- treated as 'Nothing'.
    maybeBsFromForeignPtr :: ForeignPtr a
                          -> (Ptr a -> IO CString)
                          -> IO (Maybe B.ByteString)
    maybeBsFromForeignPtr :: forall a.
    ForeignPtr a -> (Ptr a -> IO CString) -> IO (Maybe ByteString)
    maybeBsFromForeignPtr ForeignPtr a
    fp Ptr a -> IO CString
    f =
        ForeignPtr a
    -> (Ptr a -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
    withForeignPtr ForeignPtr a
    fp ((Ptr a -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr a -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr a
    p ->
            do cstr <- Ptr a -> IO CString
    f Ptr a
    p
               if cstr == nullPtr
                 then return Nothing
                 else do l <- fromIntegral `fmap` B.c_strlen cstr
                         fp' <- FC.newForeignPtr (castPtr cstr) finalizer
                         return $! Just $! B.fromForeignPtr fp' 0 l
        where
          finalizer :: IO ()
    finalizer = ForeignPtr a -> IO ()
    forall a. ForeignPtr a -> IO ()
    touchForeignPtr ForeignPtr a
    fp

    -- -- | Returns a ByteString with a finalizer that touches the ForeignPtr
    -- -- that \"owns\" the CStringLen to keep it alive.
    -- bsFromForeignPtrLen :: ForeignPtr a
    --                     -> (Ptr a -> IO CStringLen)
    --                     -> IO B.ByteString
    -- bsFromForeignPtrLen fp f =
    --     withForeignPtr fp $ \p ->
    --         do (cstr, l) <- f p
    --            if cstr == nullPtr
    --              then return ""
    --              else do fp' <- FC.newForeignPtr (castPtr cstr) finalizer
    --                      return $ B.fromForeignPtr fp' 0 l
    --     where
    --       finalizer = touchForeignPtr fp

    -- | Upon connection initialization, any notices received from the server are
    --   normally written to the console.  Notices are akin to warnings, and
    --   are distinct from notifications.  This function suppresses notices.
    --   You may later call 'enableNoticeReporting' after calling this function.
    disableNoticeReporting :: Connection -> IO ()
    disableNoticeReporting :: Connection -> IO ()
    disableNoticeReporting conn :: Connection
    conn@(Conn ForeignPtr PGconn
    _ MVar (Ptr CNoticeBuffer)
    nbRef) = do
        _ <- Connection
    -> (Ptr PGconn -> IO (FunPtr NoticeReceiver))
    -> IO (FunPtr NoticeReceiver)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    conn ((Ptr PGconn -> IO (FunPtr NoticeReceiver))
     -> IO (FunPtr NoticeReceiver))
    -> (Ptr PGconn -> IO (FunPtr NoticeReceiver))
    -> IO (FunPtr NoticeReceiver)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> Ptr PGconn
    -> FunPtr NoticeReceiver
    -> Ptr CNoticeBuffer
    -> IO (FunPtr NoticeReceiver)
    c_PQsetNoticeReceiver Ptr PGconn
    c FunPtr NoticeReceiver
    p_discard_notices Ptr CNoticeBuffer
    forall a. Ptr a
    nullPtr
        nb <- swapMVar nbRef nullPtr
        c_free_noticebuffer nb

    -- | Upon connection initialization, any notices received from the server are
    --   normally written to the console.  Notices are akin to warnings, and
    --   are distinct from notifications.  This function enables notices to be
    --   programmatically retreived using the 'getNotice' function.   You may
    --   later call 'disableNoticeReporting' after calling this function.
    enableNoticeReporting :: Connection -> IO ()
    enableNoticeReporting :: Connection -> IO ()
    enableNoticeReporting conn :: Connection
    conn@(Conn ForeignPtr PGconn
    _ MVar (Ptr CNoticeBuffer)
    nbRef) = do
      if Connection -> Bool
    isNullConnection Connection
    conn
        then () -> IO ()
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
        else do
          nb' <- IO (Ptr CNoticeBuffer)
    c_malloc_noticebuffer
          _ <- withConn conn $ \Ptr PGconn
    c -> Ptr PGconn
    -> FunPtr NoticeReceiver
    -> Ptr CNoticeBuffer
    -> IO (FunPtr NoticeReceiver)
    c_PQsetNoticeReceiver Ptr PGconn
    c FunPtr NoticeReceiver
    p_store_notices Ptr CNoticeBuffer
    nb'
          nb  <- swapMVar nbRef nb'
          c_free_noticebuffer nb

    -- |  This function retrieves any notices received from the backend.
    --    Because multiple notices can be received at a time,  you will
    --    typically want to call this function in a loop until you get
    --    back a 'Nothing'.
    getNotice :: Connection -> IO (Maybe B.ByteString)
    getNotice :: Connection -> IO (Maybe ByteString)
    getNotice (Conn ForeignPtr PGconn
    _ MVar (Ptr CNoticeBuffer)
    nbRef) =
        MVar (Ptr CNoticeBuffer)
    -> (Ptr CNoticeBuffer -> IO (Maybe ByteString))
    -> IO (Maybe ByteString)
    forall a b. MVar a -> (a -> IO b) -> IO b
    withMVar MVar (Ptr CNoticeBuffer)
    nbRef ((Ptr CNoticeBuffer -> IO (Maybe ByteString))
     -> IO (Maybe ByteString))
    -> (Ptr CNoticeBuffer -> IO (Maybe ByteString))
    -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr CNoticeBuffer
    nb -> do
          np <- Ptr CNoticeBuffer -> IO (Ptr PGnotice)
    c_get_notice Ptr CNoticeBuffer
    nb
          if np == nullPtr
            then return Nothing
            else do
              fp <- newForeignPtr finalizerFree (castPtr np)
              len  <- pgNoticePeekLen np
              return $! Just $! mkPS fp pgNoticeOffsetStr (fromIntegral len)

    -- $largeobjects

    -- | LoFd is a Large Object (pseudo) File Descriptor.  It is understood by
    -- libpq but not by operating system calls.

    newtype LoFd = LoFd CInt deriving (LoFd -> LoFd -> Bool
    (LoFd -> LoFd -> Bool) -> (LoFd -> LoFd -> Bool) -> Eq LoFd
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: LoFd -> LoFd -> Bool
    == :: LoFd -> LoFd -> Bool
    $c/= :: LoFd -> LoFd -> Bool
    /= :: LoFd -> LoFd -> Bool
    Eq, Eq LoFd
    Eq LoFd =>
    (LoFd -> LoFd -> Ordering)
    -> (LoFd -> LoFd -> Bool)
    -> (LoFd -> LoFd -> Bool)
    -> (LoFd -> LoFd -> Bool)
    -> (LoFd -> LoFd -> Bool)
    -> (LoFd -> LoFd -> LoFd)
    -> (LoFd -> LoFd -> LoFd)
    -> Ord LoFd
    LoFd -> LoFd -> Bool
    LoFd -> LoFd -> Ordering
    LoFd -> LoFd -> LoFd
    forall a.
    Eq a =>
    (a -> a -> Ordering)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> Bool)
    -> (a -> a -> a)
    -> (a -> a -> a)
    -> Ord a
    $ccompare :: LoFd -> LoFd -> Ordering
    compare :: LoFd -> LoFd -> Ordering
    $c< :: LoFd -> LoFd -> Bool
    < :: LoFd -> LoFd -> Bool
    $c<= :: LoFd -> LoFd -> Bool
    <= :: LoFd -> LoFd -> Bool
    $c> :: LoFd -> LoFd -> Bool
    > :: LoFd -> LoFd -> Bool
    $c>= :: LoFd -> LoFd -> Bool
    >= :: LoFd -> LoFd -> Bool
    $cmax :: LoFd -> LoFd -> LoFd
    max :: LoFd -> LoFd -> LoFd
    $cmin :: LoFd -> LoFd -> LoFd
    min :: LoFd -> LoFd -> LoFd
    Ord, Int -> LoFd -> [Char] -> [Char]
    [LoFd] -> [Char] -> [Char]
    LoFd -> [Char]
    (Int -> LoFd -> [Char] -> [Char])
    -> (LoFd -> [Char]) -> ([LoFd] -> [Char] -> [Char]) -> Show LoFd
    forall a.
    (Int -> a -> [Char] -> [Char])
    -> (a -> [Char]) -> ([a] -> [Char] -> [Char]) -> Show a
    $cshowsPrec :: Int -> LoFd -> [Char] -> [Char]
    showsPrec :: Int -> LoFd -> [Char] -> [Char]
    $cshow :: LoFd -> [Char]
    show :: LoFd -> [Char]
    $cshowList :: [LoFd] -> [Char] -> [Char]
    showList :: [LoFd] -> [Char] -> [Char]
    Show)

    loMode :: IOMode -> CInt
    loMode :: IOMode -> CInt
    loMode = IOMode -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt

    toMaybeOid :: Oid -> IO (Maybe Oid)
    toMaybeOid :: Oid -> IO (Maybe Oid)
    toMaybeOid Oid
    oid | Oid
    oid Oid -> Oid -> Bool
    forall a. Eq a => a -> a -> Bool
    == Oid
    invalidOid = Maybe Oid -> IO (Maybe Oid)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe Oid
    forall a. Maybe a
    Nothing
                   | Bool
    otherwise         = Maybe Oid -> IO (Maybe Oid)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Oid -> Maybe Oid
    forall a. a -> Maybe a
    Just Oid
    oid)
    {-# INLINE toMaybeOid #-}

    nonnegInt :: CInt -> IO (Maybe Int)
    nonnegInt :: CInt -> IO (Maybe Int)
    nonnegInt CInt
    x = if CInt
    x CInt -> CInt -> Bool
    forall a. Ord a => a -> a -> Bool
    < CInt
    0 then Maybe Int -> IO (Maybe Int)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe Int
    forall a. Maybe a
    Nothing else Maybe Int -> IO (Maybe Int)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Int -> Maybe Int
    forall a. a -> Maybe a
    Just (CInt -> Int
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral CInt
    x))
    {-# INLINE nonnegInt #-}

    negError  :: CInt -> IO (Maybe ())
    negError :: CInt -> IO (Maybe ())
    negError CInt
    x = if CInt
    x CInt -> CInt -> Bool
    forall a. Ord a => a -> a -> Bool
    < CInt
    0 then Maybe () -> IO (Maybe ())
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe ()
    forall a. Maybe a
    Nothing else Maybe () -> IO (Maybe ())
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (() -> Maybe ()
    forall a. a -> Maybe a
    Just ())
    {-# INLINE negError #-}

    -- | Creates a new large object,  returns the Object ID of the newly created
    -- object.

    loCreat :: Connection -> IO (Maybe Oid)
    loCreat :: Connection -> IO (Maybe Oid)
    loCreat Connection
    connection
        = Connection -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid))
    -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            Oid -> IO (Maybe Oid)
    toMaybeOid (Oid -> IO (Maybe Oid)) -> IO Oid -> IO (Maybe Oid)
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> CInt -> IO Oid
    c_lo_creat Ptr PGconn
    c (IOMode -> CInt
    loMode IOMode
    ReadMode)

    -- | Creates a new large object with a particular Object ID.  Returns
    -- 'Nothing' if the requested Object ID is already in use by some other
    -- large object or other failure.  If 'invalidOid' is used as a parameter,
    -- then 'loCreate' will assign an unused 'Oid'.

    loCreate :: Connection -> Oid -> IO (Maybe Oid)
    loCreate :: Connection -> Oid -> IO (Maybe Oid)
    loCreate Connection
    connection Oid
    oid
        = Connection -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid))
    -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            Oid -> IO (Maybe Oid)
    toMaybeOid (Oid -> IO (Maybe Oid)) -> IO Oid -> IO (Maybe Oid)
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> Oid -> IO Oid
    c_lo_create Ptr PGconn
    c Oid
    oid

    -- | Imports an operating system file as a large object.  Note that the
    -- file is read by the client interface library, not by the server; so it
    -- must exist in the client file system and be readable by the client
    -- application.

    loImport :: Connection -> FilePath -> IO (Maybe Oid)
    loImport :: Connection -> [Char] -> IO (Maybe Oid)
    loImport Connection
    connection [Char]
    filepath
        = Connection -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid))
    -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            [Char] -> (CString -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a. [Char] -> (CString -> IO a) -> IO a
    withCString [Char]
    filepath ((CString -> IO (Maybe Oid)) -> IO (Maybe Oid))
    -> (CString -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a b. (a -> b) -> a -> b
    $ \CString
    f -> do
              Oid -> IO (Maybe Oid)
    toMaybeOid (Oid -> IO (Maybe Oid)) -> IO Oid -> IO (Maybe Oid)
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> CString -> IO Oid
    c_lo_import Ptr PGconn
    c CString
    f

    -- | Imports an operating system file as a large object with the given
    -- Object ID.  Combines the behavior of 'loImport' and 'loCreate'

    loImportWithOid :: Connection -> FilePath -> Oid -> IO (Maybe Oid)
    loImportWithOid :: Connection -> [Char] -> Oid -> IO (Maybe Oid)
    loImportWithOid Connection
    connection [Char]
    filepath Oid
    oid
        = Connection -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid))
    -> (Ptr PGconn -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            [Char] -> (CString -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a. [Char] -> (CString -> IO a) -> IO a
    withCString [Char]
    filepath ((CString -> IO (Maybe Oid)) -> IO (Maybe Oid))
    -> (CString -> IO (Maybe Oid)) -> IO (Maybe Oid)
    forall a b. (a -> b) -> a -> b
    $ \CString
    f -> do
              Oid -> IO (Maybe Oid)
    toMaybeOid (Oid -> IO (Maybe Oid)) -> IO Oid -> IO (Maybe Oid)
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> CString -> Oid -> IO Oid
    c_lo_import_with_oid Ptr PGconn
    c CString
    f Oid
    oid

    -- | Exports a large object into a operating system file.  Note that
    -- the file is written by the client interface library, not the server.
    -- Returns 'Just ()' on success,  'Nothing' on failure.

    loExport :: Connection -> Oid -> FilePath -> IO (Maybe ())
    loExport :: Connection -> Oid -> [Char] -> IO (Maybe ())
    loExport Connection
    connection Oid
    oid [Char]
    filepath
        = Connection -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ()))
    -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            [Char] -> (CString -> IO (Maybe ())) -> IO (Maybe ())
    forall a. [Char] -> (CString -> IO a) -> IO a
    withCString [Char]
    filepath ((CString -> IO (Maybe ())) -> IO (Maybe ()))
    -> (CString -> IO (Maybe ())) -> IO (Maybe ())
    forall a b. (a -> b) -> a -> b
    $ \CString
    f -> do
              CInt -> IO (Maybe ())
    negError (CInt -> IO (Maybe ())) -> IO CInt -> IO (Maybe ())
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> Oid -> CString -> IO CInt
    c_lo_export Ptr PGconn
    c Oid
    oid CString
    f

    -- | Opens an existing large object for reading or writing.  The Oid specifies
    -- the large object to open.  A large object cannot be opened before it is
    -- created.  A large object descriptor is returned for later use in 'loRead',
    -- 'loWrite', 'loSeek', 'loTell', and 'loClose'.   The descriptor is only valid
    -- for the duration of the current transation.   On failure,  'Nothing' is
    -- returned.
    --
    -- The server currently does not distinguish between 'WriteMode' and
    -- 'ReadWriteMode';  write-only modes are not enforced.  However there
    -- is a significant difference between 'ReadMode' and the other modes:
    -- with 'ReadMode' you cannot write on the descriptor,  and the data read
    -- from it will reflect the contents of the large object at the time of
    -- the transaction snapshot that was active when 'loOpen' was executed,
    -- regardless of later writes by this or other transactions.   Reading from
    -- a descriptor opened in 'WriteMode', 'ReadWriteMode', or 'AppendMode'
    -- returns data that reflects all writes of other committed transactions
    -- as well as the writes of the current transaction.   This is similar to
    -- the behavior of @REPEATABLE READ@ versus @READ COMMITTED@ transaction
    -- modes for ordinary SQL @SELECT@ commands.

    loOpen :: Connection -> Oid -> IOMode -> IO (Maybe LoFd)
    loOpen :: Connection -> Oid -> IOMode -> IO (Maybe LoFd)
    loOpen Connection
    connection Oid
    oid IOMode
    mode
        = Connection -> (Ptr PGconn -> IO (Maybe LoFd)) -> IO (Maybe LoFd)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe LoFd)) -> IO (Maybe LoFd))
    -> (Ptr PGconn -> IO (Maybe LoFd)) -> IO (Maybe LoFd)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            fd <- Ptr PGconn -> Oid -> CInt -> IO CInt
    c_lo_open Ptr PGconn
    c Oid
    oid (IOMode -> CInt
    loMode IOMode
    mode)
            case fd of
              -1                     -> Maybe LoFd -> IO (Maybe LoFd)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe LoFd
    forall a. Maybe a
    Nothing
              CInt
    _ | IOMode
    mode IOMode -> IOMode -> Bool
    forall a. Eq a => a -> a -> Bool
    /= IOMode
    AppendMode -> Maybe LoFd -> IO (Maybe LoFd)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (LoFd -> Maybe LoFd
    forall a. a -> Maybe a
    Just (CInt -> LoFd
    LoFd CInt
    fd))
                | Bool
    otherwise -> do
                    -- The Large Object API does not directly support AppendMode,
                    -- so we emulate it.

                    -- FIXME:  review this emulation as it and/or the error
                    --         handling is likely to be slightly wrong.  Start by
                    --         reading the source of lo_open, lo_lseek, and
                    --         lo_close.
                    err <- Ptr PGconn -> CInt -> CInt -> CInt -> IO CInt
    c_lo_lseek Ptr PGconn
    c CInt
    fd CInt
    0 (SeekMode -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt SeekMode
    SeekFromEnd)
                    case err of
                      -1 -> do
                              -- the lo_lseek failed, so we try to close the fd

                              -- I'm  not sure what to do if lo_close fails so I am
                              -- ignoring it.  This might obscure the error message
                              -- available from PQerrorMessage
                              _ <- Ptr PGconn -> CInt -> IO CInt
    c_lo_close Ptr PGconn
    c CInt
    fd
                              return Nothing
                      CInt
    _  -> Maybe LoFd -> IO (Maybe LoFd)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (LoFd -> Maybe LoFd
    forall a. a -> Maybe a
    Just (CInt -> LoFd
    LoFd CInt
    fd))

    -- | @loWrite conn fd buf@ writes the bytestring @buf@ to the large object
    -- descriptor @fd@.  The number of bytes actually written is returned.
    -- In the event of an error, 'Nothing' is returned.

    loWrite :: Connection -> LoFd -> B.ByteString -> IO (Maybe Int)
    loWrite :: Connection -> LoFd -> ByteString -> IO (Maybe Int)
    loWrite Connection
    connection (LoFd CInt
    fd) ByteString
    bytes
        = Connection -> (Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int))
    -> (Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            ByteString -> (CStringLen -> IO (Maybe Int)) -> IO (Maybe Int)
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
    B.unsafeUseAsCStringLen ByteString
    bytes ((CStringLen -> IO (Maybe Int)) -> IO (Maybe Int))
    -> (CStringLen -> IO (Maybe Int)) -> IO (Maybe Int)
    forall a b. (a -> b) -> a -> b
    $ \(CString
    byteptr,Int
    len) -> do
              CInt -> IO (Maybe Int)
    nonnegInt (CInt -> IO (Maybe Int)) -> IO CInt -> IO (Maybe Int)
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> CInt -> CString -> CSize -> IO CInt
    c_lo_write Ptr PGconn
    c CInt
    fd CString
    byteptr (Int -> CSize
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    len)

    -- | @loRead conn fd len@ reads up to @len@ bytes from the large object
    -- descriptor @fd@.  In the event of an error,  'Nothing' is returned.

    loRead :: Connection -> LoFd -> Int -> IO (Maybe B.ByteString)
    loRead :: Connection -> LoFd -> Int -> IO (Maybe ByteString)
    loRead Connection
    connection (LoFd !CInt
    fd) !Int
    maxlen
        = Connection
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString))
    -> (Ptr PGconn -> IO (Maybe ByteString)) -> IO (Maybe ByteString)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            buf <- Int -> IO (Ptr Word8)
    forall a. Int -> IO (Ptr a)
    mallocBytes Int
    maxlen
            len_ <- c_lo_read c fd buf (fromIntegral maxlen)
            let len = CInt -> Int
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral CInt
    len_
            if len < 0
              then do
                      free buf
                      return Nothing
              else do
                      bufre <- reallocBytes buf len
                      buffp <- newForeignPtr finalizerFree bufre
                      return $! Just $! B.fromForeignPtr buffp 0 len

    -- | Changes the current read or write location associated with
    -- a large object descriptor.    The return value is the new location
    -- pointer,  or 'Nothing' on error.

    loSeek :: Connection -> LoFd -> SeekMode -> Int -> IO (Maybe Int)
    loSeek :: Connection -> LoFd -> SeekMode -> Int -> IO (Maybe Int)
    loSeek Connection
    connection (LoFd CInt
    fd) SeekMode
    seekmode Int
    delta
        = Connection -> (Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int))
    -> (Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            let d :: CInt
    d = Int -> CInt
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    delta
            pos <- Ptr PGconn -> CInt -> CInt -> CInt -> IO CInt
    c_lo_lseek Ptr PGconn
    c CInt
    fd CInt
    d (CInt -> IO CInt) -> CInt -> IO CInt
    forall a b. (a -> b) -> a -> b
    $ SeekMode -> CInt
    forall a. ToCInt a => a -> CInt
    toCInt SeekMode
    seekmode
            nonnegInt pos

    -- | Obtains the current read or write location of a large object descriptor.

    loTell :: Connection -> LoFd -> IO (Maybe Int)
    loTell :: Connection -> LoFd -> IO (Maybe Int)
    loTell Connection
    connection (LoFd CInt
    fd)
        = Connection -> (Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int)
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int))
    -> (Ptr PGconn -> IO (Maybe Int)) -> IO (Maybe Int)
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            CInt -> IO (Maybe Int)
    nonnegInt (CInt -> IO (Maybe Int)) -> IO CInt -> IO (Maybe Int)
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> CInt -> IO CInt
    c_lo_tell Ptr PGconn
    c CInt
    fd

    -- | Truncates a large object to a given length.  If the length is greater
    -- than the current large object,  then the large object is extended with
    -- null bytes.  ('\x00')
    --
    -- The file offest is not changed.
    --
    -- 'loTruncate' is new as of PostgreSQL 8.3; if this function is run against
    -- an older server version, it will fail and return 'Nothing'

    loTruncate :: Connection -> LoFd -> Int -> IO (Maybe ())
    loTruncate :: Connection -> LoFd -> Int -> IO (Maybe ())
    loTruncate Connection
    connection (LoFd CInt
    fd) Int
    size
        = Connection -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ()))
    -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            CInt -> IO (Maybe ())
    negError (CInt -> IO (Maybe ())) -> IO CInt -> IO (Maybe ())
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> CInt -> CSize -> IO CInt
    c_lo_truncate Ptr PGconn
    c CInt
    fd (Int -> CSize
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral Int
    size)

    -- | Closes a large object descriptor.  Any large object descriptors that
    -- remain open at the end of a transaction will be closed automatically.

    loClose :: Connection -> LoFd -> IO (Maybe ())
    loClose :: Connection -> LoFd -> IO (Maybe ())
    loClose Connection
    connection (LoFd CInt
    fd)
        = Connection -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ()))
    -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            CInt -> IO (Maybe ())
    negError (CInt -> IO (Maybe ())) -> IO CInt -> IO (Maybe ())
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> CInt -> IO CInt
    c_lo_close Ptr PGconn
    c CInt
    fd

    -- | Removes a large object from the database.

    loUnlink :: Connection -> Oid -> IO (Maybe ())
    loUnlink :: Connection -> Oid -> IO (Maybe ())
    loUnlink Connection
    connection Oid
    oid
        = Connection -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
    withConn Connection
    connection ((Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ()))
    -> (Ptr PGconn -> IO (Maybe ())) -> IO (Maybe ())
    forall a b. (a -> b) -> a -> b
    $ \Ptr PGconn
    c -> do
            CInt -> IO (Maybe ())
    negError (CInt -> IO (Maybe ())) -> IO CInt -> IO (Maybe ())
    forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
    =<< Ptr PGconn -> Oid -> IO CInt
    c_lo_unlink Ptr PGconn
    c Oid
    oid