-- -*- mode: haskell; -*- {-# CFILES hdbc-postgresql-helper.c #-} -- Above line for hugs {- Copyright (C) 2005 John Goerzen This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA -} module Database.HDBC.PostgreSQL.Statement where import Database.HDBC.Types import Database.HDBC import Database.HDBC.PostgreSQL.Types import Database.HDBC.PostgreSQL.Utils import Foreign.C.Types import Foreign.ForeignPtr import Foreign.Ptr import Control.Concurrent.MVar import Foreign.C.String import Foreign.Marshal import Foreign.Storable import Control.Monad import Data.List import Data.Word import Control.Exception import System.IO import Database.HDBC.PostgreSQL.Parser(convertSQL) import Database.HDBC.DriverUtils import Database.HDBC.PostgreSQL.PTypeConv l _ = return () --l m = hPutStrLn stderr ("\n" ++ m) #include data SState = SState { stomv :: MVar (Maybe Stmt), nextrowmv :: MVar (CInt), -- -1 for no next row (empty); otherwise, next row to read. dbo :: Conn, squery :: String, coldefmv :: MVar [(String, SqlColDesc)]} -- FIXME: we currently do no prepare optimization whatsoever. newSth :: Conn -> ChildList -> String -> IO Statement newSth indbo mchildren query = do l "in newSth" newstomv <- newMVar Nothing newnextrowmv <- newMVar (-1) newcoldefmv <- newMVar [] usequery <- case convertSQL query of Left errstr -> throwDyn $ SqlError {seState = "", seNativeError = (-1), seErrorMsg = "hdbc prepare: " ++ show errstr} Right converted -> return converted let sstate = SState {stomv = newstomv, nextrowmv = newnextrowmv, dbo = indbo, squery = usequery, coldefmv = newcoldefmv} let retval = Statement {execute = fexecute sstate, executeMany = fexecutemany sstate, finish = public_ffinish sstate, fetchRow = ffetchrow sstate, originalQuery = query, getColumnNames = fgetColumnNames sstate, describeResult = fdescribeResult sstate} addChild mchildren retval return retval fgetColumnNames sstate = do c <- readMVar (coldefmv sstate) return (map fst c) fdescribeResult sstate = readMVar (coldefmv sstate) {- For now, we try to just handle things as simply as possible. FIXME lots of room for improvement here (types, etc). -} fexecute sstate args = withConn (dbo sstate) $ \cconn -> withCString (squery sstate) $ \cquery -> withCStringArr0 args $ \cargs -> do l "in fexecute" public_ffinish sstate -- Sets nextrowmv to -1 resptr <- pqexecParams cconn cquery (genericLength args) nullPtr cargs nullPtr nullPtr 0 status <- pqresultStatus resptr case status of #{const PGRES_EMPTY_QUERY} -> do l $ "PGRES_EMPTY_QUERY: " ++ squery sstate pqclear_raw resptr swapMVar (coldefmv sstate) [] return 0 #{const PGRES_COMMAND_OK} -> do l $ "PGRES_COMMAND_OK: " ++ squery sstate rowscs <- pqcmdTuples resptr rows <- peekCString rowscs pqclear_raw resptr swapMVar (coldefmv sstate) [] return $ case rows of "" -> 0 x -> read x #{const PGRES_TUPLES_OK} -> do l $ "PGRES_TUPLES_OK: " ++ squery sstate fgetcoldef resptr >>= swapMVar (coldefmv sstate) numrows <- pqntuples resptr if numrows < 1 then do pqclear_raw resptr return 0 else do wrappedptr <- withRawConn (dbo sstate) (\rawconn -> wrapstmt resptr rawconn) fresptr <- newForeignPtr pqclearptr wrappedptr swapMVar (nextrowmv sstate) 0 swapMVar (stomv sstate) (Just fresptr) return 0 _ -> do l $ "PGRES ERROR: " ++ squery sstate csstatusmsg <- pqresStatus status cserrormsg <- pqresultErrorMessage resptr statusmsg <- peekCString csstatusmsg errormsg <- peekCString cserrormsg pqclear_raw resptr throwDyn $ SqlError {seState = "", seNativeError = fromIntegral status, seErrorMsg = "execute: " ++ statusmsg ++ ": " ++ errormsg} {- General algorithm: find out how many columns we have, check the type of each to see if it's NULL. If it's not, fetch it as text and return that. -} ffetchrow :: SState -> IO (Maybe [SqlValue]) ffetchrow sstate = modifyMVar (nextrowmv sstate) dofetchrow where dofetchrow (-1) = l "ffr -1" >> return ((-1), Nothing) dofetchrow nextrow = modifyMVar (stomv sstate) $ \stmt -> case stmt of Nothing -> l "ffr nos" >> return (stmt, ((-1), Nothing)) Just cmstmt -> withStmt cmstmt $ \cstmt -> do l $ "ffetchrow: " ++ show nextrow numrows <- pqntuples cstmt l $ "numrows: " ++ show numrows if nextrow >= numrows then do l "no more rows" -- Don't use public_ffinish here ffinish cmstmt return (Nothing, ((-1), Nothing)) else do l "getting stuff" ncols <- pqnfields cstmt res <- mapM (getCol cstmt nextrow) [0..(ncols - 1)] return (stmt, (nextrow + 1, Just res)) getCol p row icol = do isnull <- pqgetisnull p row icol if isnull /= 0 then return SqlNull else do text <- pqgetvalue p row icol s <- peekCString text return (SqlString s) fgetcoldef cstmt = do ncols <- pqnfields cstmt mapM desccol [0..(ncols - 1)] where desccol i = do colname <- (pqfname cstmt i >>= peekCString) coltype <- pqftype cstmt i --coloctets <- pqfsize let coldef = oidToColDef coltype return (colname, coldef) -- FIXME: needs a faster algorithm. fexecutemany :: SState -> [[SqlValue]] -> IO () fexecutemany sstate arglist = mapM_ (fexecute sstate) arglist >> return () -- Finish and change state public_ffinish sstate = do l "public_ffinish" swapMVar (nextrowmv sstate) (-1) modifyMVar_ (stomv sstate) worker where worker Nothing = return Nothing worker (Just sth) = ffinish sth >> return Nothing ffinish :: Stmt -> IO () ffinish p = withRawStmt p $ pqclear foreign import ccall unsafe "libpq-fe.h PQresultStatus" pqresultStatus :: (Ptr CStmt) -> IO #{type ExecStatusType} foreign import ccall unsafe "libpq-fe.h PQexecParams" pqexecParams :: (Ptr CConn) -> CString -> CInt -> (Ptr #{type Oid}) -> (Ptr CString) -> (Ptr CInt) -> (Ptr CInt) -> CInt -> IO (Ptr CStmt) foreign import ccall unsafe "hdbc-postgresql-helper.h PQclear_app" pqclear :: Ptr WrappedCStmt -> IO () foreign import ccall unsafe "hdbc-postgresql-helper.h &PQclear_finalizer" pqclearptr :: FunPtr (Ptr WrappedCStmt -> IO ()) foreign import ccall unsafe "libpq-fe.h PQclear" pqclear_raw :: Ptr CStmt -> IO () foreign import ccall unsafe "hdbc-postgresql-helper.h wrapobjpg" wrapstmt :: Ptr CStmt -> Ptr WrappedCConn -> IO (Ptr WrappedCStmt) foreign import ccall unsafe "libpq-fe.h PQcmdTuples" pqcmdTuples :: Ptr CStmt -> IO CString foreign import ccall unsafe "libpq-fe.h PQresStatus" pqresStatus :: #{type ExecStatusType} -> IO CString foreign import ccall unsafe "libpq-fe.h PQresultErrorMessage" pqresultErrorMessage :: (Ptr CStmt) -> IO CString foreign import ccall unsafe "libpq-fe.h PQntuples" pqntuples :: Ptr CStmt -> IO CInt foreign import ccall unsafe "libpq-fe.h PQnfields" pqnfields :: Ptr CStmt -> IO CInt foreign import ccall unsafe "libpq-fe.h PQgetisnull" pqgetisnull :: Ptr CStmt -> CInt -> CInt -> IO CInt foreign import ccall unsafe "libpq-fe.h PQgetvalue" pqgetvalue :: Ptr CStmt -> CInt -> CInt -> IO CString foreign import ccall unsafe "libpq-fe.h PQfname" pqfname :: Ptr CStmt -> CInt -> IO CString foreign import ccall unsafe "libpq-fe.h PQftype" pqftype :: Ptr CStmt -> CInt -> IO #{type Oid}