public void PqsqlConnectionTest4()
{
PqsqlConnection connection = new PqsqlConnection(connectionString);
connection.Open();
Assert.AreEqual(ConnectionState.Open, connection.State, "wrong connection state");
IntPtr conn_attempt1 = connection.PGConnection;
int sock1 = PqsqlWrapper.PQsocket(conn_attempt1);
Assert.AreNotEqual(-1, sock1, "wrong socket");
// close the underlying socket without letting Pqsql and libpq know
int closed = CloseSocket(sock1);
Assert.AreEqual(0, closed, "closesocket failed");
connection.Close();
Assert.AreEqual(ConnectionState.Closed, connection.State, "wrong connection state");
connection.Open();
IntPtr conn_attempt2 = connection.PGConnection;
ConnStatusType status = PqsqlWrapper.PQstatus(conn_attempt2);
Assert.AreEqual(ConnStatusType.CONNECTION_OK, status, "connection broken");
Assert.AreEqual(ConnectionState.Open, connection.State, "wrong connection state");
int sock2 = PqsqlWrapper.PQsocket(conn_attempt2);
// close the underlying socket without letting Pqsql and libpq know
closed = CloseSocket(sock2);
Assert.AreEqual(0, closed, "closesocket failed");
}
internal static IntPtr SetupPGConn(PqsqlConnectionStringBuilder connStringBuilder, out ConnStatusType connStatus, out PGTransactionStatusType tranStatus)
{
#if CODECONTRACTS
Contract.Requires <ArgumentNullException>(connStringBuilder != null);
#else
if (connStringBuilder == null)
{
throw new ArgumentNullException(nameof(connStringBuilder));
}
#endif
// setup null-terminated key-value arrays for the connection
string[] keys = new string[connStringBuilder.Keys.Count + 1];
string[] vals = new string[connStringBuilder.Values.Count + 1];
// get keys and values from PqsqlConnectionStringBuilder
connStringBuilder.Keys.CopyTo(keys, 0);
connStringBuilder.Values.CopyTo(vals, 0);
// now create connection
IntPtr conn = PqsqlWrapper.PQconnectdbParams(keys, vals, 0);
if (conn == IntPtr.Zero)
{
connStatus = ConnStatusType.CONNECTION_BAD;
tranStatus = PGTransactionStatusType.PQTRANS_UNKNOWN;
return(conn);
}
// always force client_encoding to utf8
int client_encoding = PqsqlWrapper.PQclientEncoding(conn);
if (client_encoding == (int)PgEnc.PG_UTF8) // done
{
connStatus = PqsqlWrapper.PQstatus(conn);
tranStatus = PqsqlWrapper.PQtransactionStatus(conn);
}
else if (client_encoding == -1) // bail out, but keep connection object
{
connStatus = ConnStatusType.CONNECTION_BAD;
tranStatus = PGTransactionStatusType.PQTRANS_UNKNOWN;
}
else // try to set client_encoding to utf8
{
if (PqsqlWrapper.PQsetClientEncoding(conn, PgEncName.PG_UTF8) == 0) // success
{
connStatus = PqsqlWrapper.PQstatus(conn);
tranStatus = PqsqlWrapper.PQtransactionStatus(conn);
}
else // bail out, but keep connection object
{
connStatus = ConnStatusType.CONNECTION_BAD;
tranStatus = PGTransactionStatusType.PQTRANS_UNKNOWN;
}
}
return(conn);
}
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
}
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);
}