// call PQexec
internal ExecStatusType Exec(byte[] stmt, out IntPtr res)
{
if (mConnection == IntPtr.Zero)
{
res = IntPtr.Zero;
return(ExecStatusType.PGRES_FATAL_ERROR);
}
unsafe
{
fixed(byte *st = stmt)
{
res = PqsqlWrapper.PQexec(mConnection, st);
}
}
ExecStatusType s = ExecStatusType.PGRES_FATAL_ERROR;
if (res != IntPtr.Zero)
{
s = PqsqlWrapper.PQresultStatus(res);
}
return(s);
}
public void End()
{
IntPtr res;
string err = string.Empty;
#if CODECONTRACTS
Contract.Assume(mConn != null);
#endif
IntPtr conn = mConn.PGConnection;
if (mColBuf == IntPtr.Zero)
{
return;
}
int ret = PqsqlBinaryFormat.pqcb_put_end(mColBuf); // flush column buffer
if (ret != 1)
{
err = err.Insert(0, "Could not send end-of-data indication: ");
goto bailout;
}
res = PqsqlWrapper.PQgetResult(conn);
if (res != IntPtr.Zero)
{
ExecStatusType s = PqsqlWrapper.PQresultStatus(res);
PqsqlWrapper.PQclear(res);
if (s == ExecStatusType.PGRES_COPY_IN)
{
// still in COPY_IN mode? bail out!
byte[] b = PqsqlUTF8Statement.CreateUTF8Statement("COPY FROM cancelled by client");
unsafe
{
fixed(byte *bs = b)
{
ret = PqsqlWrapper.PQputCopyEnd(conn, bs);
}
}
res = PqsqlWrapper.PQgetResult(conn);
if (res != IntPtr.Zero)
{
s = PqsqlWrapper.PQresultStatus(res);
PqsqlWrapper.PQclear(res);
}
err = err.Insert(0, "Cancelled COPY FROM while still in COPY_IN mode (" + s + "," + ret + "): ");
goto bailout;
}
if (s != ExecStatusType.PGRES_COMMAND_OK)
{
err = err.Insert(0, "COPY FROM failed (" + s + "): ");
goto bailout;
}
// consume all remaining results until we reach the NULL result
while ((res = PqsqlWrapper.PQgetResult(conn)) != IntPtr.Zero)
{
// always free mResult
PqsqlWrapper.PQclear(res);
}
return;
}
bailout:
err += mConn.GetErrorMessage();
throw new PqsqlException(err);
}
private static bool CheckOrRelease(IntPtr pgConn, out ConnStatusType connStatus, out PGTransactionStatusType tranStatus)
{
if (pgConn == IntPtr.Zero)
{
connStatus = ConnStatusType.CONNECTION_BAD;
tranStatus = PGTransactionStatusType.PQTRANS_UNKNOWN;
return(false);
}
// is connection reusable?
connStatus = PqsqlWrapper.PQstatus(pgConn);
if (connStatus != ConnStatusType.CONNECTION_OK)
{
goto broken;
}
tranStatus = PqsqlWrapper.PQtransactionStatus(pgConn);
if (tranStatus != PGTransactionStatusType.PQTRANS_IDLE)
{
goto broken;
}
//
// now check the connection: first try to fix the client encoding if it is not utf8 for some reason.
// if client_encoding is utf8, we send the empty query to check whether the socket is still usable
// for the backend communiction. here, we could make use of tcp_keepalive settings.
//
int client_encoding = PqsqlWrapper.PQclientEncoding(pgConn);
if (client_encoding == -1)
{
goto broken;
}
if (client_encoding == (int)PgEnc.PG_UTF8) // client_encoding == utf8
{
// send empty query to test whether we are really connected (tcp_keepalive might have closed socket)
unsafe
{
byte[] empty = { 0 }; // empty query string
fixed(byte *eq = empty)
{
if (PqsqlWrapper.PQsendQuery(pgConn, eq) == 0) // could not send query
{
goto broken;
}
}
}
// Reading result: consume and clear remaining results until we reach the NULL result.
// PQgetResult will block here
IntPtr res;
ExecStatusType st = ExecStatusType.PGRES_EMPTY_QUERY;
while ((res = PqsqlWrapper.PQgetResult(pgConn)) != IntPtr.Zero)
{
ExecStatusType st0 = PqsqlWrapper.PQresultStatus(res);
if (st0 != ExecStatusType.PGRES_EMPTY_QUERY)
{
st = st0;
}
// always free res
PqsqlWrapper.PQclear(res);
}
if (st != ExecStatusType.PGRES_EMPTY_QUERY) // received wrong exec status
{
goto broken;
}
}
else // set client_encoding to utf8
{
// set client_encoding to test whether we are really connected (tcp_keepalive might have closed socket)
if (PqsqlWrapper.PQsetClientEncoding(pgConn, PgEncName.PG_UTF8) != 0)
{
goto broken;
}
}
return(true); // successfully reused connection
broken:
// reconnect with current connection setting
PqsqlWrapper.PQreset(pgConn);
connStatus = PqsqlWrapper.PQstatus(pgConn);
if (connStatus == ConnStatusType.CONNECTION_OK)
{
tranStatus = PqsqlWrapper.PQtransactionStatus(pgConn);
if (tranStatus == PGTransactionStatusType.PQTRANS_IDLE)
{
return(true); // successfully reconnected
}
}
else
{
tranStatus = PGTransactionStatusType.PQTRANS_UNKNOWN;
}
// could not reconnect: finally give up and clean up memory
PqsqlWrapper.PQfinish(pgConn);
return(false);
}
private static bool DiscardConnection(IntPtr conn)
{
if (conn == IntPtr.Zero)
{
return(false);
}
bool rollback = false;
ConnStatusType cs = PqsqlWrapper.PQstatus(conn);
if (cs != ConnStatusType.CONNECTION_OK)
{
return(false); // connection broken
}
PGTransactionStatusType ts = PqsqlWrapper.PQtransactionStatus(conn);
switch (ts)
{
case PGTransactionStatusType.PQTRANS_INERROR: /* idle, within failed transaction */
case PGTransactionStatusType.PQTRANS_INTRANS: /* idle, within transaction block */
rollback = true;
break;
case PGTransactionStatusType.PQTRANS_IDLE: /* connection idle */
// nothing to do
break;
// PGTransactionStatusType.PQTRANS_ACTIVE: /* command in progress */
// PGTransactionStatusType.PQTRANS_UNKNOWN: /* cannot determine status */
default:
return(false); // connection broken
}
IntPtr res;
ExecStatusType s = ExecStatusType.PGRES_FATAL_ERROR;
// we need to rollback before we can discard the connection
if (rollback)
{
unsafe
{
fixed(byte *st = PqsqlTransaction.RollbackStatement)
{
res = PqsqlWrapper.PQexec(conn, st);
if (res != IntPtr.Zero)
{
s = PqsqlWrapper.PQresultStatus(res);
PqsqlWrapper.PQclear(res);
}
}
}
if (s != ExecStatusType.PGRES_COMMAND_OK)
{
return(false); // connection broken
}
s = ExecStatusType.PGRES_FATAL_ERROR;
}
// discard connection
unsafe
{
fixed(byte *st = DiscardAllStatement)
{
res = PqsqlWrapper.PQexec(conn, st);
if (res != IntPtr.Zero)
{
s = PqsqlWrapper.PQresultStatus(res);
PqsqlWrapper.PQclear(res);
}
}
}
if (s != ExecStatusType.PGRES_COMMAND_OK)
{
return(false); // connection broken
}
return(true); // connection successfully resetted
}
protected string Error()
{
IntPtr res;
string err = string.Empty;
IntPtr conn = mConn.PGConnection;
res = PqsqlWrapper.PQgetResult(conn);
if (res != IntPtr.Zero)
{
ExecStatusType s = PqsqlWrapper.PQresultStatus(res);
PqsqlWrapper.PQclear(res);
if (s == ExecStatusType.PGRES_COPY_IN || s == ExecStatusType.PGRES_COPY_OUT)
{
if (s == ExecStatusType.PGRES_COPY_IN)
{
// still in COPY_IN mode? bail out!
byte[] b = PqsqlUTF8Statement.CreateUTF8Statement("COPY cancelled by client");
int end;
unsafe
{
fixed(byte *bs = b)
{
end = PqsqlWrapper.PQputCopyEnd(conn, bs);
}
}
if (end != 1)
{
err = err.Insert(0, "Cannot cancel COPY (" + s + "): ");
goto bailout;
}
}
res = PqsqlWrapper.PQgetResult(conn);
if (res != IntPtr.Zero)
{
s = PqsqlWrapper.PQresultStatus(res);
PqsqlWrapper.PQclear(res);
}
}
if (s != ExecStatusType.PGRES_COMMAND_OK)
{
err = err.Insert(0, "COPY failed (" + s + "): ");
goto bailout;
}
// consume all remaining results until we reach the NULL result
while ((res = PqsqlWrapper.PQgetResult(conn)) != IntPtr.Zero)
{
// always free mResult
PqsqlWrapper.PQclear(res);
}
return(err);
}
bailout:
err += mConn.GetErrorMessage();
return(err);
}
