-----------------------------------------------------------------------------
-- |
-- 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

    -- * 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

-- $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 =
    forall a. IO a -> IO a
mask_ forall a b. (a -> b) -> a -> b
$ do
       Ptr PGconn
connPtr <- forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
conninfo CString -> IO (Ptr PGconn)
c_PQconnectdb
       if Ptr PGconn
connPtr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
           then forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail [Char]
"libpq failed to allocate a PGconn structure"
           else do
             MVar (Ptr CNoticeBuffer)
noticeBuffer <- forall a. a -> IO (MVar a)
newMVar forall a. Ptr a
nullPtr
             ForeignPtr PGconn
connection <- forall a. Ptr a -> IO () -> IO (ForeignPtr a)
newForeignPtrOnce Ptr PGconn
connPtr (Ptr PGconn -> MVar (Ptr CNoticeBuffer) -> IO ()
pqfinish Ptr PGconn
connPtr MVar (Ptr CNoticeBuffer)
noticeBuffer)
             forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! ForeignPtr PGconn -> MVar (Ptr CNoticeBuffer) -> Connection
Conn ForeignPtr PGconn
connection MVar (Ptr CNoticeBuffer)
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 =
    forall a. IO a -> IO a
mask_ forall a b. (a -> b) -> a -> b
$ do
       Ptr PGconn
connPtr <- forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
connStr CString -> IO (Ptr PGconn)
c_PQconnectStart
       if Ptr PGconn
connPtr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
           then forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail [Char]
"libpq failed to allocate a PGconn structure"
           else do
             MVar (Ptr CNoticeBuffer)
noticeBuffer <- forall a. a -> IO (MVar a)
newMVar forall a. Ptr a
nullPtr
             ForeignPtr PGconn
connection <- forall a. Ptr a -> IO () -> IO (ForeignPtr a)
newForeignPtrOnce Ptr PGconn
connPtr (Ptr PGconn -> MVar (Ptr CNoticeBuffer) -> IO ()
pqfinish Ptr PGconn
connPtr MVar (Ptr CNoticeBuffer)
noticeBuffer)
             forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! ForeignPtr PGconn -> MVar (Ptr CNoticeBuffer) -> Connection
Conn ForeignPtr PGconn
connection MVar (Ptr CNoticeBuffer)
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.
   CInt
mfd <- Ptr PGconn -> IO CInt
c_PQsocket Ptr PGconn
conn
   case CInt
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)

   Ptr CNoticeBuffer
nb <- forall a. MVar a -> a -> IO a
swapMVar MVar (Ptr CNoticeBuffer)
noticeBuffer forall a. Ptr a
nullPtr
   Ptr CNoticeBuffer -> IO ()
c_free_noticebuffer Ptr CNoticeBuffer
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
    MVar (IO ())
mv <- forall a. a -> IO (MVar a)
newMVar IO ()
fin
    forall a. Ptr a -> IO () -> IO (ForeignPtr a)
FC.newForeignPtr Ptr a
ptr forall a b. (a -> b) -> a -> b
$ forall a. MVar a -> IO (Maybe a)
tryTakeMVar MVar (IO ())
mv forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= forall b a. b -> (a -> b) -> Maybe a -> b
maybe (forall (m :: * -> *) a. Monad m => a -> m a
return ()) forall a. a -> a
id

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

-- | Test if a connection is the Null Connection.
isNullConnection :: Connection -> Bool
isNullConnection :: Connection -> Bool
isNullConnection (Conn ForeignPtr PGconn
x MVar (Ptr CNoticeBuffer)
_) = forall a. ForeignPtr a -> Ptr a
Unsafe.unsafeForeignPtrToPtr ForeignPtr PGconn
x forall a. Eq a => a -> a -> Bool
== 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 = 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 =
    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 CInt
code <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO CInt
poller
       forall b a. b -> (a -> b) -> Maybe a -> b
maybe
         (forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail forall a b. (a -> b) -> a -> b
$ [Char]
"unexpected polling status " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> [Char]
show CInt
code)
         forall (m :: * -> *) a. Monad m => a -> m a
return
         (forall a. FromCInt a => CInt -> Maybe a
fromCInt CInt
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 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 =
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
ptr ->
        do CString
cstr <- Ptr PGconn -> IO CString
f Ptr PGconn
ptr
           if CString
cstr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
             then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
             else forall a. a -> Maybe a
Just forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CString -> IO ByteString
B.packCString CString
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
  CInt
stat <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO CInt
c_PQstatus
  forall b a. b -> (a -> b) -> Maybe a -> b
maybe
    (forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail forall a b. (a -> b) -> a -> b
$ [Char]
"Unknown connection status " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> [Char]
show CInt
stat)
    forall (m :: * -> *) a. Monad m => a -> m a
return
    (forall a. FromCInt a => CInt -> Maybe a
fromCInt CInt
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
  CInt
stat <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO CInt
c_PQtransactionStatus
  forall b a. b -> (a -> b) -> Maybe a -> b
maybe
    (forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail forall a b. (a -> b) -> a -> b
$ [Char]
"Unknown transaction status " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> [Char]
show CInt
stat)
    forall (m :: * -> *) a. Monad m => a -> m a
return
    (forall a. FromCInt a => CInt -> Maybe a
fromCInt CInt
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 =
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
connPtr ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
paramName forall a b. (a -> b) -> a -> b
$ \CString
paramNamePtr ->
        do CString
cstr <- Ptr PGconn -> CString -> IO CString
c_PQparameterStatus Ptr PGconn
connPtr CString
paramNamePtr
           if CString
cstr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
             then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
             else forall a. a -> Maybe a
Just forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CString -> IO ByteString
B.packCString CString
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 =
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (Integral a, Num b) => a -> b
fromIntegral forall a b. (a -> b) -> a -> b
$ 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 =
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (Integral a, Num b) => a -> b
fromIntegral forall a b. (a -> b) -> a -> b
$ 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 = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap 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 CInt
cFd <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO CInt
c_PQsocket
       case CInt
cFd of
         -1 -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
         CInt
_  -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. a -> Maybe a
Just 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 =
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (Integral a, Num b) => a -> b
fromIntegral forall a b. (a -> b) -> a -> b
$ 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 =
    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 =
    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
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: Result -> Result -> Bool
$c/= :: Result -> Result -> Bool
== :: Result -> Result -> Bool
$c== :: Result -> Result -> Bool
Eq, Int -> Result -> ShowS
[Result] -> ShowS
Result -> [Char]
forall a.
(Int -> a -> ShowS) -> (a -> [Char]) -> ([a] -> ShowS) -> Show a
showList :: [Result] -> ShowS
$cshowList :: [Result] -> ShowS
show :: Result -> [Char]
$cshow :: Result -> [Char]
showsPrec :: Int -> Result -> ShowS
$cshowsPrec :: Int -> Result -> ShowS
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) =
    case Format
format of
        Format
Binary -> forall a. ByteString -> (CString -> IO a) -> IO a
B.unsafeUseAsCString ByteString
bs
        Format
Text   -> forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
bs

-- | 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 =
    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
unsafeWithArray Int
n [Oid]
oids forall a b. (a -> b) -> a -> b
$ \Ptr Oid
ts ->
        forall a b res.
(a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res
withMany (forall a b c.
(a -> (Ptr b -> IO c) -> IO c)
-> Maybe a -> (Ptr b -> IO c) -> IO c
maybeWith forall a. (ByteString, Format) -> (CString -> IO a) -> IO a
unsafeUseParamAsCString) [Maybe (ByteString, Format)]
values forall a b. (a -> b) -> a -> b
$ \[CString]
c_values ->
            forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
unsafeWithArray Int
n [CString]
c_values forall a b. (a -> b) -> a -> b
$ \Ptr CString
vs ->
                forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
unsafeWithArray Int
n [CInt]
c_lengths forall a b. (a -> b) -> a -> b
$ \Ptr CInt
ls ->
                    forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
unsafeWithArray Int
n [CInt]
formats 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 =
        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 forall a. Num a => a -> a -> a
+ Int
1) (Oid
invalidOid forall a. a -> [a] -> [a]
: [Oid]
a) (forall a. Maybe a
Nothing forall a. a -> [a] -> [a]
: [Maybe (ByteString, Format)]
b) (CInt
0 forall a. a -> [a] -> [a]
: [CInt]
c) (CInt
0 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 = forall a. ToCInt a => a -> CInt
toCInt Format
f
        in Int
-> [Oid]
-> [Maybe (ByteString, Format)]
-> [CInt]
-> [CInt]
-> AccumParams
AccumParams (Int
i forall a. Num a => a -> a -> a
+ Int
1) (Oid
t forall a. a -> [a] -> [a]
: [Oid]
xs) (forall a. a -> Maybe a
Just (ByteString
v, Format
f) forall a. a -> [a] -> [a]
: [Maybe (ByteString, Format)]
ys) (CInt
z forall a. a -> [a] -> [a]
: [CInt]
zs) (CInt
w forall a. a -> [a] -> [a]
: [CInt]
ws)

intToCInt :: Int -> CInt
intToCInt :: Int -> CInt
intToCInt = 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 =
    forall a b res.
(a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res
withMany (forall a b c.
(a -> (Ptr b -> IO c) -> IO c)
-> Maybe a -> (Ptr b -> IO c) -> IO c
maybeWith forall a. (ByteString, Format) -> (CString -> IO a) -> IO a
unsafeUseParamAsCString) [Maybe (ByteString, Format)]
values forall a b. (a -> b) -> a -> b
$ \[CString]
c_values ->
        forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
unsafeWithArray Int
n [CString]
c_values forall a b. (a -> b) -> a -> b
$ \Ptr CString
vs ->
            forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
unsafeWithArray Int
n [CInt]
c_lengths forall a b. (a -> b) -> a -> b
$ \Ptr CInt
ls ->
                forall a b. Storable a => Int -> [a] -> (Ptr a -> IO b) -> IO b
unsafeWithArray Int
n [CInt]
formats 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 =
        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 forall a. Num a => a -> a -> a
+ Int
1) (forall a. Maybe a
Nothing forall a. a -> [a] -> [a]
: [Maybe (ByteString, Format)]
a) (CInt
0 forall a. a -> [a] -> [a]
: [CInt]
b) (CInt
0 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 = forall a. ToCInt a => a -> CInt
toCInt Format
f
        in Int
-> [Maybe (ByteString, Format)]
-> [CInt]
-> [CInt]
-> AccumPrepParams
AccumPrepParams (Int
i forall a. Num a => a -> a -> a
+ Int
1) (forall a. a -> Maybe a
Just (ByteString
v, Format
f) forall a. a -> [a] -> [a]
: [Maybe (ByteString, Format)]
xs) (CInt
y forall a. a -> [a] -> [a]
: [CInt]
ys) (CInt
z 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 forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
p ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
query 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 forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
statement forall a b. (a -> b) -> a -> b
$ \CString
s ->
            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 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 = 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 forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
stmtName forall a b. (a -> b) -> a -> b
$ \CString
s ->
            forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
query forall a b. (a -> b) -> a -> b
$ \CString
q ->
                forall a b c.
(a -> (Int -> Ptr b -> IO c) -> IO c)
-> Maybe a -> (Int -> Ptr b -> IO c) -> IO c
maybeWithInt forall a b. Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
withArrayLen Maybe [Oid]
mParamTypes 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 forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
stmtName forall a b. (a -> b) -> a -> b
$ \CString
s ->
            forall a.
[Maybe (ByteString, Format)]
-> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a) -> IO a
withParamsPrepared [Maybe (ByteString, Format)]
params 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 = 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 forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
stmtName 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 forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
portalName 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 = 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 CString
cstr <- CInt -> IO CString
c_PQresStatus forall a b. (a -> b) -> a -> b
$ forall a. ToCInt a => a -> CInt
toCInt ExecStatus
es
       CSize
len <- CString -> IO CSize
B.c_strlen CString
cstr
       ForeignPtr Word8
fp <- forall a. Ptr a -> IO (ForeignPtr a)
newForeignPtr_ forall a b. (a -> b) -> a -> b
$ forall a b. Ptr a -> Ptr b
castPtr CString
cstr
       forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
fp Int
0 forall a b. (a -> b) -> a -> b
$ forall a b. (Integral a, Num b) => a -> b
fromIntegral CSize
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 = 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) = 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 =
    forall a.
ForeignPtr a -> (Ptr a -> IO CString) -> IO (Maybe ByteString)
maybeBsFromForeignPtr ForeignPtr PGresult
fp forall a b. (a -> b) -> a -> b
$ \Ptr PGresult
res ->
        Ptr PGresult -> CInt -> IO CString
c_PQresultErrorField Ptr PGresult
res forall a b. (a -> b) -> a -> b
$ 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 = forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
res (forall (m :: * -> *) a. Monad m => a -> m a
return forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Integral a => a -> Row
toRow 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 = forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
res (forall (m :: * -> *) a. Monad m => a -> m a
return forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Integral a => a -> Column
toColumn forall b c a. (b -> c) -> (a -> b) -> a -> c
. Ptr PGresult -> CInt
c_PQnfields)


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

toColumn :: (Integral a) => a -> Column
toColumn :: forall a. Integral a => a -> Column
toColumn = CInt -> Column
Col forall b c a. (b -> c) -> (a -> b) -> a -> c
. 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 forall b c a. (b -> c) -> (a -> b) -> a -> c
. 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 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 CInt
num <- forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
res forall a b. (a -> b) -> a -> b
$ \Ptr PGresult
resPtr ->
              forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
columnName forall a b. (a -> b) -> a -> b
$ \CString
columnNamePtr ->
                  Ptr PGresult -> CString -> IO CInt
c_PQfnumber Ptr PGresult
resPtr CString
columnNamePtr
       if CInt
num forall a. Eq a => a -> a -> Bool
== -CInt
1
         then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
         else forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$ forall a. Integral a => a -> Column
toColumn CInt
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) = forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
result 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) =
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap CInt -> Column
Col forall a b. (a -> b) -> a -> b
$ forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
result 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) =
    forall b. FromCInt b => Result -> (Ptr PGresult -> IO CInt) -> IO b
enumFromResult Result
result 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) = forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
result 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) = forall a b.
(Integral a, Num b) =>
Result -> (Ptr PGresult -> IO a) -> IO b
numFromResult Result
result 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) = forall a b.
(Integral a, Num b) =>
Result -> (Ptr PGresult -> IO a) -> IO b
numFromResult Result
result 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) =
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr PGresult
fp forall a b. (a -> b) -> a -> b
$ \Ptr PGresult
ptr -> do
      CInt
isnull <- Ptr PGresult -> CInt -> CInt -> IO CInt
c_PQgetisnull Ptr PGresult
ptr CInt
rowNum CInt
colNum
      case forall a. FromCInt a => CInt -> Maybe a
fromCInt CInt
isnull of
        Just Bool
True  -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
        Just Bool
False -> do
          CString
cstr <- Ptr PGresult -> CInt -> CInt -> IO CString
c_PQgetvalue Ptr PGresult
ptr CInt
rowNum CInt
colNum
          CInt
l <- Ptr PGresult -> CInt -> CInt -> IO CInt
c_PQgetlength Ptr PGresult
ptr CInt
rowNum CInt
colNum
          ForeignPtr Word8
fp' <- forall a. Ptr a -> IO () -> IO (ForeignPtr a)
FC.newForeignPtr (forall a b. Ptr a -> Ptr b
castPtr CString
cstr) IO ()
finalizer
          forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
fp' Int
0 forall a b. (a -> b) -> a -> b
$ forall a b. (Integral a, Num b) => a -> b
fromIntegral CInt
l
        Maybe Bool
Nothing -> forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail forall a b. (a -> b) -> a -> b
$ [Char]
"fromCInt @Bool " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> [Char]
show CInt
isnull

    where
      finalizer :: IO ()
finalizer = 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) =
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
res forall a b. (a -> b) -> a -> b
$ \Ptr PGresult
ptr -> do
      CInt
isnull <- Ptr PGresult -> CInt -> CInt -> IO CInt
c_PQgetisnull Ptr PGresult
ptr CInt
rowNum CInt
colNum
      case forall a. FromCInt a => CInt -> Maybe a
fromCInt CInt
isnull of
        Just Bool
True  -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
        Just Bool
False -> do
          CString
cstr <- Ptr PGresult -> CInt -> CInt -> IO CString
c_PQgetvalue Ptr PGresult
ptr CInt
rowNum CInt
colNum
          Int
l <- forall a b. (Integral a, Num b) => a -> b
fromIntegral forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` Ptr PGresult -> CInt -> CInt -> IO CInt
c_PQgetlength Ptr PGresult
ptr CInt
rowNum CInt
colNum
          forall a. a -> Maybe a
Just forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CStringLen -> IO ByteString
B.packCStringLen (CString
cstr, Int
l)
        Maybe Bool
Nothing -> forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail forall a b. (a -> b) -> a -> b
$ [Char]
"fromCInt @Bool " forall a. [a] -> [a] -> [a]
++ 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) =
    forall b. FromCInt b => Result -> (Ptr PGresult -> IO CInt) -> IO b
enumFromResult Result
result 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) =
    forall a b.
(Integral a, Num b) =>
Result -> (Ptr PGresult -> IO a) -> IO b
numFromResult Result
result 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 = 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 =
    forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
result forall a b. (a -> b) -> a -> b
$ \Ptr PGresult
p -> Ptr PGresult -> CInt -> IO Oid
c_PQparamtype Ptr PGresult
p forall a b. (a -> b) -> a -> b
$ 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 = 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 = 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 =
  forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
conn ->
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
B.unsafeUseAsCStringLen ByteString
bs forall a b. (a -> b) -> a -> b
$ \(CString
from, Int
bslen) ->
      forall a b. Storable a => (Ptr a -> IO b) -> IO b
alloca forall a b. (a -> b) -> a -> b
$ \Ptr CInt
err -> do
        ByteString
xs <- Int -> (Ptr Word8 -> IO Int) -> IO ByteString
B.createAndTrim (Int
bslenforall a. Num a => a -> a -> a
*Int
2forall a. Num a => a -> a -> a
+Int
1) forall a b. (a -> b) -> a -> b
$ \Ptr Word8
to ->
                 forall a b. (Integral a, Num b) => a -> b
fromIntegral 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 (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
bslen) Ptr CInt
err
        CInt
stat <- forall a. Storable a => Ptr a -> IO a
peek Ptr CInt
err
        case CInt
stat of
          CInt
0 -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. a -> Maybe a
Just ByteString
xs
          CInt
_ -> forall (m :: * -> *) a. Monad m => a -> m a
return 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 =
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
conn ->
        forall a. ByteString -> (CStringLen -> IO a) -> IO a
B.unsafeUseAsCStringLen ByteString
bs forall a b. (a -> b) -> a -> b
$ \(CString
from, Int
bslen) ->
            forall a b. Storable a => (Ptr a -> IO b) -> IO b
alloca forall a b. (a -> b) -> a -> b
$ \Ptr CSize
to_length -> do
              Ptr Word8
to <- Ptr PGconn -> CString -> CSize -> Ptr CSize -> IO (Ptr Word8)
c_PQescapeByteaConn Ptr PGconn
conn CString
from (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
bslen) Ptr CSize
to_length
              if Ptr Word8
to forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
                then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
                else do ForeignPtr Word8
tofp <- forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr forall a. FunPtr (Ptr a -> IO ())
p_PQfreemem Ptr Word8
to
                        CSize
l <- forall a. Storable a => Ptr a -> IO a
peek Ptr CSize
to_length
                        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
tofp Int
0 ((forall a b. (Integral a, Num b) => a -> b
fromIntegral CSize
l) forall a. Num a => a -> a -> a
- Int
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 =
    forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
bs forall a b. (a -> b) -> a -> b
$ \CString
from ->
        forall a b. Storable a => (Ptr a -> IO b) -> IO b
alloca forall a b. (a -> b) -> a -> b
$ \Ptr CSize
to_length -> do
          Ptr Word8
to <- CString -> Ptr CSize -> IO (Ptr Word8)
c_PQunescapeBytea CString
from Ptr CSize
to_length
          if Ptr Word8
to forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
            then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
            else do ForeignPtr Word8
tofp <- forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr forall a. FunPtr (Ptr a -> IO ())
p_PQfreemem Ptr Word8
to
                    CSize
l <- forall a. Storable a => Ptr a -> IO a
peek Ptr CSize
to_length
                    forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
tofp Int
0 forall a b. (a -> b) -> a -> b
$ forall a b. (Integral a, Num b) => a -> b
fromIntegral CSize
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 =
  forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
conn ->
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
B.unsafeUseAsCStringLen ByteString
bs forall a b. (a -> b) -> a -> b
$ \(CString
from, Int
bslen) -> forall a. IO a -> IO a
mask_ forall a b. (a -> b) -> a -> b
$ do
      CString
bs'ptr <- Ptr PGconn -> CString -> CSize -> IO CString
c_PQescapeIdentifier Ptr PGconn
conn CString
from (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
bslen)
      if CString
bs'ptr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
        then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
        else do
            ByteString
bs' <- CString -> IO ByteString
B.packCString CString
bs'ptr
            forall a. Ptr a -> IO ()
c_PQfreemem CString
bs'ptr
            forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. a -> Maybe a
Just ByteString
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
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: CopyInResult -> CopyInResult -> Bool
$c/= :: CopyInResult -> CopyInResult -> Bool
== :: CopyInResult -> CopyInResult -> Bool
$c== :: CopyInResult -> CopyInResult -> Bool
Eq, Int -> CopyInResult -> ShowS
[CopyInResult] -> ShowS
CopyInResult -> [Char]
forall a.
(Int -> a -> ShowS) -> (a -> [Char]) -> ([a] -> ShowS) -> Show a
showList :: [CopyInResult] -> ShowS
$cshowList :: [CopyInResult] -> ShowS
show :: CopyInResult -> [Char]
$cshow :: CopyInResult -> [Char]
showsPrec :: Int -> CopyInResult -> ShowS
$cshowsPrec :: Int -> CopyInResult -> ShowS
Show)


toCopyInResult :: CInt -> IO CopyInResult
toCopyInResult :: CInt -> IO CopyInResult
toCopyInResult CInt
n | CInt
n forall a. Ord a => a -> a -> Bool
< CInt
0     = forall (m :: * -> *) a. Monad m => a -> m a
return CopyInResult
CopyInError
                 | CInt
n forall a. Eq a => a -> a -> Bool
== CInt
0    = forall (m :: * -> *) a. Monad m => a -> m a
return CopyInResult
CopyInWouldBlock
                 | Bool
otherwise = 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 =
    forall a. ByteString -> (CStringLen -> IO a) -> IO a
B.unsafeUseAsCStringLen ByteString
bs 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 forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<<
        (forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
conn forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
ptr -> Ptr PGconn -> CString -> CInt -> IO CInt
c_PQputCopyData Ptr PGconn
ptr CString
str (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 forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<<
        (forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
conn forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
ptr -> Ptr PGconn -> CString -> IO CInt
c_PQputCopyEnd Ptr PGconn
ptr forall a. Ptr a
nullPtr)
putCopyEnd Connection
conn (Just ByteString
errormsg) =
    CInt -> IO CopyInResult
toCopyInResult forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<<
        (forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
errormsg forall a b. (a -> b) -> a -> b
$ \CString
errormsg_cstr ->
            forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
conn 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 -> ShowS
[CopyOutResult] -> ShowS
CopyOutResult -> [Char]
forall a.
(Int -> a -> ShowS) -> (a -> [Char]) -> ([a] -> ShowS) -> Show a
showList :: [CopyOutResult] -> ShowS
$cshowList :: [CopyOutResult] -> ShowS
show :: CopyOutResult -> [Char]
$cshow :: CopyOutResult -> [Char]
showsPrec :: Int -> CopyOutResult -> ShowS
$cshowsPrec :: Int -> CopyOutResult -> ShowS
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 = forall a b. Storable a => (Ptr a -> IO b) -> IO b
alloca forall a b. (a -> b) -> a -> b
$ \Ptr (Ptr Word8)
strp -> forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
conn forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
    CInt
len <- Ptr PGconn -> Ptr (Ptr Word8) -> CInt -> IO CInt
c_PQgetCopyData Ptr PGconn
c Ptr (Ptr Word8)
strp forall a b. (a -> b) -> a -> b
$! forall a. ToCInt a => a -> CInt
toCInt Bool
async
    if CInt
len forall a. Ord a => a -> a -> Bool
<= CInt
0
      then case forall a. Ord a => a -> a -> Ordering
compare CInt
len (-CInt
1) of
             Ordering
LT -> forall (m :: * -> *) a. Monad m => a -> m a
return CopyOutResult
CopyOutError
             Ordering
EQ -> forall (m :: * -> *) a. Monad m => a -> m a
return CopyOutResult
CopyOutDone
             Ordering
GT -> forall (m :: * -> *) a. Monad m => a -> m a
return CopyOutResult
CopyOutWouldBlock
      else do
        ForeignPtr Word8
fp <- forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr forall a. FunPtr (Ptr a -> IO ())
p_PQfreemem forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<< forall a. Storable a => Ptr a -> IO a
peek Ptr (Ptr Word8)
strp
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! ByteString -> CopyOutResult
CopyOutRow (ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
fp Int
0 (forall a b. (Integral a, Num b) => a -> b
fromIntegral CInt
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 =
    forall b.
FromCInt b =>
Connection -> (Ptr PGconn -> IO CInt) -> IO b
enumFromConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
p ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
query 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 =
    forall b.
FromCInt b =>
Connection -> (Ptr PGconn -> IO CInt) -> IO b
enumFromConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
statement forall a b. (a -> b) -> a -> b
$ \CString
s ->
            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 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 = 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 =
    forall b.
FromCInt b =>
Connection -> (Ptr PGconn -> IO CInt) -> IO b
enumFromConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
stmtName forall a b. (a -> b) -> a -> b
$ \CString
s ->
            forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
query forall a b. (a -> b) -> a -> b
$ \CString
q ->
                forall a b c.
(a -> (Int -> Ptr b -> IO c) -> IO c)
-> Maybe a -> (Int -> Ptr b -> IO c) -> IO c
maybeWithInt forall a b. Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
withArrayLen Maybe [Oid]
mParamTypes 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 =
    forall b.
FromCInt b =>
Connection -> (Ptr PGconn -> IO CInt) -> IO b
enumFromConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
stmtName forall a b. (a -> b) -> a -> b
$ \CString
s ->
            forall a.
[Maybe (ByteString, Format)]
-> (CInt -> Ptr CString -> Ptr CInt -> Ptr CInt -> IO a) -> IO a
withParamsPrepared [Maybe (ByteString, Format)]
params 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 = 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 =
    forall b.
FromCInt b =>
Connection -> (Ptr PGconn -> IO CInt) -> IO b
enumFromConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
stmtName 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 =
    forall b.
FromCInt b =>
Connection -> (Ptr PGconn -> IO CInt) -> IO b
enumFromConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c ->
        forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString ByteString
portalName 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 Ptr PGresult
resPtr <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO (Ptr PGresult)
c_PQgetResult
       if Ptr PGresult
resPtr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
           then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
           else (forall a. a -> Maybe a
Just forall b c a. (b -> c) -> (a -> b) -> a -> c
. ForeignPtr PGresult -> Result
Result) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr FunPtr (Ptr PGresult -> IO ())
p_PQclear Ptr PGresult
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 = 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 = 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
       CInt
stat <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
ptr -> Ptr PGconn -> CInt -> IO CInt
c_PQsetnonblocking Ptr PGconn
ptr (forall a. ToCInt a => a -> CInt
toCInt Bool
blocking)
       forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! CInt
stat forall a. Eq a => a -> a -> Bool
== CInt
0


-- | Returns the blocking status of the database connection.
isnonblocking :: Connection
              -> IO Bool
isnonblocking :: Connection -> IO Bool
isnonblocking Connection
connection = 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 = 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
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: FlushStatus -> FlushStatus -> Bool
$c/= :: FlushStatus -> FlushStatus -> Bool
== :: FlushStatus -> FlushStatus -> Bool
$c== :: FlushStatus -> FlushStatus -> Bool
Eq, Int -> FlushStatus -> ShowS
[FlushStatus] -> ShowS
FlushStatus -> [Char]
forall a.
(Int -> a -> ShowS) -> (a -> [Char]) -> ([a] -> ShowS) -> Show a
showList :: [FlushStatus] -> ShowS
$cshowList :: [FlushStatus] -> ShowS
show :: FlushStatus -> [Char]
$cshow :: FlushStatus -> [Char]
showsPrec :: Int -> FlushStatus -> ShowS
$cshowsPrec :: Int -> FlushStatus -> ShowS
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 CInt
stat <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO CInt
c_PQflush
       case CInt
stat of
         CInt
0 -> forall (m :: * -> *) a. Monad m => a -> m a
return FlushStatus
FlushOk
         CInt
1 -> forall (m :: * -> *) a. Monad m => a -> m a
return FlushStatus
FlushWriting
         CInt
_ -> forall (m :: * -> *) a. Monad m => a -> m a
return FlushStatus
FlushFailed


-- $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
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: Cancel -> Cancel -> Bool
$c/= :: Cancel -> Cancel -> Bool
== :: Cancel -> Cancel -> Bool
$c== :: Cancel -> Cancel -> Bool
Eq, Int -> Cancel -> ShowS
[Cancel] -> ShowS
Cancel -> [Char]
forall a.
(Int -> a -> ShowS) -> (a -> [Char]) -> ([a] -> ShowS) -> Show a
showList :: [Cancel] -> ShowS
$cshowList :: [Cancel] -> ShowS
show :: Cancel -> [Char]
$cshow :: Cancel -> [Char]
showsPrec :: Int -> Cancel -> ShowS
$cshowsPrec :: Int -> Cancel -> ShowS
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 =
    forall a. IO a -> IO a
mask_ forall a b. (a -> b) -> a -> b
$ forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
conn ->
        do Ptr PGcancel
ptr <- Ptr PGconn -> IO (Ptr PGcancel)
c_PQgetCancel Ptr PGconn
conn
           if Ptr PGcancel
ptr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
             then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
             else do ForeignPtr PGcancel
fp <- forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr FunPtr (Ptr PGcancel -> IO ())
p_PQfreeCancel Ptr PGcancel
ptr
                     forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$ ForeignPtr PGcancel -> Cancel
Cancel ForeignPtr PGcancel
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) =
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr PGcancel
fp forall a b. (a -> b) -> a -> b
$ \Ptr PGcancel
ptr -> do
        forall a b. Int -> (Ptr a -> IO b) -> IO b
allocaBytes Int
errbufsize forall a b. (a -> b) -> a -> b
$ \CString
errbuf -> do
            CInt
res <- Ptr PGcancel -> CString -> CInt -> IO CInt
c_PQcancel Ptr PGcancel
ptr CString
errbuf forall a b. (a -> b) -> a -> b
$ forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
errbufsize
            case CInt
res of
              CInt
1 -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ forall a b. b -> Either a b
Right ()
              CInt
_ -> forall a b. a -> Either a b
Left 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 =
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
ptr ->
        do Ptr Notify
mn <- Ptr PGconn -> IO (Ptr Notify)
c_PQnotifies Ptr PGconn
ptr
           if Ptr Notify
mn forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
             then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
             else do
                     Maybe Notify
result <- forall a. a -> Maybe a
Just forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` forall a. Storable a => Ptr a -> IO a
peek Ptr Notify
mn
                     forall a. Ptr a -> IO ()
c_PQfreemem Ptr Notify
mn
                     forall (m :: * -> *) a. Monad m => a -> m a
return Maybe Notify
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 =
    forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
ptr ->
        do CInt
i <- Ptr PGconn -> IO CInt
c_PQclientEncoding Ptr PGconn
ptr
           CString
cstr <- CInt -> IO CString
c_pg_encoding_to_char CInt
i
           CSize
len <- CString -> IO CSize
B.c_strlen CString
cstr
           ForeignPtr Word8
fp <- forall a. Ptr a -> IO (ForeignPtr a)
newForeignPtr_ forall a b. (a -> b) -> a -> b
$ forall a b. Ptr a -> Ptr b
castPtr CString
cstr
           forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
fp Int
0 forall a b. (a -> b) -> a -> b
$ forall a b. (Integral a, Num b) => a -> b
fromIntegral CSize
len


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

       forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! CInt
stat forall a. Eq a => a -> a -> Bool
== CInt
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 =
    forall b.
FromCInt b =>
Connection -> (Ptr PGconn -> IO CInt) -> IO b
enumFromConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
p ->
        Ptr PGconn -> CInt -> IO CInt
c_PQsetErrorVerbosity Ptr PGconn
p forall a b. (a -> b) -> a -> b
$ 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 = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO CInt
f forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= forall b a. b -> (a -> b) -> Maybe a -> b
maybe (forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail [Char]
"enumFromConn") forall (m :: * -> *) a. Monad m => a -> m a
return forall b c a. (b -> c) -> (a -> b) -> a -> c
. 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 =
    forall a. IO a -> IO a
mask_ forall a b. (a -> b) -> a -> b
$ do
       Ptr PGresult
resPtr <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection Ptr PGconn -> IO (Ptr PGresult)
f
       if Ptr PGresult
resPtr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
           then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
           else (forall a. a -> Maybe a
Just forall b c a. (b -> c) -> (a -> b) -> a -> c
. ForeignPtr PGresult -> Result
Result) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr FunPtr (Ptr PGresult -> IO ())
p_PQclear Ptr PGresult
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 = 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 = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap forall a b. (Integral a, Num b) => a -> b
fromIntegral forall a b. (a -> b) -> a -> b
$ 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 = forall b. Result -> (Ptr PGresult -> IO b) -> IO b
withResult Result
result Ptr PGresult -> IO CInt
f forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= forall b a. b -> (a -> b) -> Maybe a -> b
maybe (forall (m :: * -> *) a. MonadFail m => [Char] -> m a
fail [Char]
"enumFromResult") forall (m :: * -> *) a. Monad m => a -> m a
return forall b c a. (b -> c) -> (a -> b) -> a -> c
. 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 = 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 =
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr a
fp forall a b. (a -> b) -> a -> b
$ \Ptr a
p ->
        do CString
cstr <- Ptr a -> IO CString
f Ptr a
p
           if CString
cstr forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
             then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
             else do Int
l <- forall a b. (Integral a, Num b) => a -> b
fromIntegral forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CString -> IO CSize
B.c_strlen CString
cstr
                     ForeignPtr Word8
fp' <- forall a. Ptr a -> IO () -> IO (ForeignPtr a)
FC.newForeignPtr (forall a b. Ptr a -> Ptr b
castPtr CString
cstr) IO ()
finalizer
                     forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
fp' Int
0 Int
l
    where
      finalizer :: IO ()
finalizer = 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
    FunPtr NoticeReceiver
_ <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
conn 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 forall a. Ptr a
nullPtr
    Ptr CNoticeBuffer
nb <- forall a. MVar a -> a -> IO a
swapMVar MVar (Ptr CNoticeBuffer)
nbRef forall a. Ptr a
nullPtr
    Ptr CNoticeBuffer -> IO ()
c_free_noticebuffer Ptr CNoticeBuffer
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 forall (m :: * -> *) a. Monad m => a -> m a
return ()
    else do
      Ptr CNoticeBuffer
nb' <- IO (Ptr CNoticeBuffer)
c_malloc_noticebuffer
      FunPtr NoticeReceiver
_ <- forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
conn 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_store_notices Ptr CNoticeBuffer
nb'
      Ptr CNoticeBuffer
nb  <- forall a. MVar a -> a -> IO a
swapMVar MVar (Ptr CNoticeBuffer)
nbRef Ptr CNoticeBuffer
nb'
      Ptr CNoticeBuffer -> IO ()
c_free_noticebuffer Ptr CNoticeBuffer
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) =
    forall a b. MVar a -> (a -> IO b) -> IO b
withMVar MVar (Ptr CNoticeBuffer)
nbRef forall a b. (a -> b) -> a -> b
$ \Ptr CNoticeBuffer
nb -> do
      Ptr PGnotice
np <- Ptr CNoticeBuffer -> IO (Ptr PGnotice)
c_get_notice Ptr CNoticeBuffer
nb
      if Ptr PGnotice
np forall a. Eq a => a -> a -> Bool
== forall a. Ptr a
nullPtr
        then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
        else do
          ForeignPtr Word8
fp <- forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr forall a. FunPtr (Ptr a -> IO ())
finalizerFree (forall a b. Ptr a -> Ptr b
castPtr Ptr PGnotice
np)
          CSize
len  <- Ptr PGnotice -> IO CSize
pgNoticePeekLen Ptr PGnotice
np
          forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> Int -> ByteString
mkPS ForeignPtr Word8
fp Int
pgNoticeOffsetStr (forall a b. (Integral a, Num b) => a -> b
fromIntegral CSize
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
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: LoFd -> LoFd -> Bool
$c/= :: LoFd -> LoFd -> Bool
== :: LoFd -> LoFd -> Bool
$c== :: LoFd -> LoFd -> Bool
Eq, Eq 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
min :: LoFd -> LoFd -> LoFd
$cmin :: LoFd -> LoFd -> LoFd
max :: LoFd -> LoFd -> LoFd
$cmax :: LoFd -> LoFd -> LoFd
>= :: LoFd -> LoFd -> Bool
$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
compare :: LoFd -> LoFd -> Ordering
$ccompare :: LoFd -> LoFd -> Ordering
Ord, Int -> LoFd -> ShowS
[LoFd] -> ShowS
LoFd -> [Char]
forall a.
(Int -> a -> ShowS) -> (a -> [Char]) -> ([a] -> ShowS) -> Show a
showList :: [LoFd] -> ShowS
$cshowList :: [LoFd] -> ShowS
show :: LoFd -> [Char]
$cshow :: LoFd -> [Char]
showsPrec :: Int -> LoFd -> ShowS
$cshowsPrec :: Int -> LoFd -> ShowS
Show)

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

toMaybeOid :: Oid -> IO (Maybe Oid)
toMaybeOid :: Oid -> IO (Maybe Oid)
toMaybeOid Oid
oid | Oid
oid forall a. Eq a => a -> a -> Bool
== Oid
invalidOid = forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
               | Bool
otherwise         = forall (m :: * -> *) a. Monad m => a -> m a
return (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 forall a. Ord a => a -> a -> Bool
< CInt
0 then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing else forall (m :: * -> *) a. Monad m => a -> m a
return (forall a. a -> Maybe a
Just (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 forall a. Ord a => a -> a -> Bool
< CInt
0 then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing else forall (m :: * -> *) a. Monad m => a -> m a
return (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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        Oid -> IO (Maybe Oid)
toMaybeOid 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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        Oid -> IO (Maybe Oid)
toMaybeOid 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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        forall a. [Char] -> (CString -> IO a) -> IO a
withCString [Char]
filepath forall a b. (a -> b) -> a -> b
$ \CString
f -> do
          Oid -> IO (Maybe Oid)
toMaybeOid 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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        forall a. [Char] -> (CString -> IO a) -> IO a
withCString [Char]
filepath forall a b. (a -> b) -> a -> b
$ \CString
f -> do
          Oid -> IO (Maybe Oid)
toMaybeOid 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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        forall a. [Char] -> (CString -> IO a) -> IO a
withCString [Char]
filepath forall a b. (a -> b) -> a -> b
$ \CString
f -> do
          CInt -> IO (Maybe ())
negError 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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        CInt
fd <- Ptr PGconn -> Oid -> CInt -> IO CInt
c_lo_open Ptr PGconn
c Oid
oid (IOMode -> CInt
loMode IOMode
mode)
        case CInt
fd of
          -1                     -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
          CInt
_ | IOMode
mode forall a. Eq a => a -> a -> Bool
/= IOMode
AppendMode -> forall (m :: * -> *) a. Monad m => a -> m a
return (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.
                CInt
err <- Ptr PGconn -> CInt -> CInt -> CInt -> IO CInt
c_lo_lseek Ptr PGconn
c CInt
fd CInt
0 (forall a. ToCInt a => a -> CInt
toCInt SeekMode
SeekFromEnd)
                case CInt
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
                          CInt
_ <- Ptr PGconn -> CInt -> IO CInt
c_lo_close Ptr PGconn
c CInt
fd
                          forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
                  CInt
_  -> forall (m :: * -> *) a. Monad m => a -> m a
return (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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        forall a. ByteString -> (CStringLen -> IO a) -> IO a
B.unsafeUseAsCStringLen ByteString
bytes forall a b. (a -> b) -> a -> b
$ \(CString
byteptr,Int
len) -> do
          CInt -> IO (Maybe Int)
nonnegInt 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 (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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        Ptr Word8
buf <- forall a. Int -> IO (Ptr a)
mallocBytes Int
maxlen
        CInt
len_ <- Ptr PGconn -> CInt -> Ptr Word8 -> CSize -> IO CInt
c_lo_read Ptr PGconn
c CInt
fd Ptr Word8
buf (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
maxlen)
        let len :: Int
len = forall a b. (Integral a, Num b) => a -> b
fromIntegral CInt
len_
        if Int
len forall a. Ord a => a -> a -> Bool
< Int
0
          then do
                  forall a. Ptr a -> IO ()
free Ptr Word8
buf
                  forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
          else do
                  Ptr Word8
bufre <- forall a. Ptr a -> Int -> IO (Ptr a)
reallocBytes Ptr Word8
buf Int
len
                  ForeignPtr Word8
buffp <- forall a. FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
newForeignPtr forall a. FunPtr (Ptr a -> IO ())
finalizerFree Ptr Word8
bufre
                  forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! forall a. a -> Maybe a
Just forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> Int -> ByteString
B.fromForeignPtr ForeignPtr Word8
buffp Int
0 Int
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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        let d :: CInt
d = forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
delta
        CInt
pos <- Ptr PGconn -> CInt -> CInt -> CInt -> IO CInt
c_lo_lseek Ptr PGconn
c CInt
fd CInt
d forall a b. (a -> b) -> a -> b
$ forall a. ToCInt a => a -> CInt
toCInt SeekMode
seekmode
        CInt -> IO (Maybe Int)
nonnegInt CInt
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)
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        CInt -> IO (Maybe Int)
nonnegInt 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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        CInt -> IO (Maybe ())
negError 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 (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)
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        CInt -> IO (Maybe ())
negError 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
    = forall b. Connection -> (Ptr PGconn -> IO b) -> IO b
withConn Connection
connection forall a b. (a -> b) -> a -> b
$ \Ptr PGconn
c -> do
        CInt -> IO (Maybe ())
negError 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