public byte receive() throws EdbcEx {
int msg_id;
if (trace.enabled(3)) trace.write(title + ": reading next message");
/*
** Check to see if message header is in the input
** buffer (handles message concatenation).
*/
while (in.avail() < 8) {
short tl_id;
/*
** Headers are not split across continued messages.
** Data remaining in the current buffer indicates
** a message processing error.
*/
if (in.avail() > 0) {
if (trace.enabled(1))
trace.write(title + ": invalid header length " + in.avail() + " bytes");
disconnect();
throw EdbcEx.get(E_IO0002_PROTOCOL_ERR);
}
try {
tl_id = in.receive();
} catch (EdbcEx ex) {
disconnect();
throw ex;
}
if (tl_id != JDBC_TL_DT) {
if (trace.enabled(1))
trace.write(title + ": invalid TL packet ID 0x" + Integer.toHexString(tl_id));
disconnect();
throw EdbcEx.get(E_IO0002_PROTOCOL_ERR);
}
}
/*
** Read and validate message header.
*/
if ((msg_id = in.readInt()) != JDBC_MSG_ID) {
if (trace.enabled(1))
trace.write(title + ": invalid header ID 0x" + Integer.toHexString(msg_id));
disconnect();
throw EdbcEx.get(E_IO0002_PROTOCOL_ERR);
}
in_msg_len = in.readShort();
in_msg_id = in.readByte();
in_msg_flg = in.readByte();
if (trace.enabled(2))
trace.write(
title
+ ": received message "
+ IdMap.map(in_msg_id, MsgConst.msgMap)
+ " length "
+ in_msg_len
+ ((in_msg_flg & JDBC_MSG_EOD) == 0 ? "" : " EOD")
+ ((in_msg_flg & JDBC_MSG_EOG) == 0 ? "" : " EOG"));
return (in_msg_id);
} // receive
public short readShort() throws EdbcEx {
need(2, true);
in_msg_len -= 2;
return (in.readShort());
} // readShort
protected DbConnIn(String host_id, byte info[], short info_len) throws EdbcEx {
super(host_id, info, info_len);
try {
in = new InBuff(socket.getInputStream(), conn_id, 1 << JDBC_TL_PKT_MIN);
} catch (Exception ex) {
if (trace.enabled(1))
trace.write(title + ": error creating input buffer: " + ex.getMessage());
disconnect();
throw EdbcEx.get(E_IO0001_CONNECT_ERR, ex);
}
String cs = null; // Character set connection parameter
int size = JDBC_TL_PKT_MIN;
short tl_id;
try {
if (trace.enabled(2)) trace.write(title + ": reading Connection Confirmation");
if ((tl_id = in.receive()) != JDBC_TL_CC) {
if (trace.enabled(1)) trace.write(title + ": invalid TL CC packet ID " + tl_id);
throw EdbcEx.get(E_IO0001_CONNECT_ERR);
}
/*
** Read negotiated values from server (if available).
*/
while (in.avail() >= 2) {
byte param_id = in.readByte();
short param_len = (short) (in.readByte() & 0xff);
if (param_len == 255)
if (in.avail() >= 2) param_len = in.readShort();
else throw EdbcEx.get(E_IO0001_CONNECT_ERR);
if (in.avail() < param_len) throw EdbcEx.get(E_IO0001_CONNECT_ERR);
switch (param_id) {
case JDBC_TL_CP_PROTO:
if (param_len == 1) tl_proto = in.readByte();
else throw EdbcEx.get(E_IO0001_CONNECT_ERR);
break;
case JDBC_TL_CP_SIZE:
if (param_len == 1) size = in.readByte();
else throw EdbcEx.get(E_IO0001_CONNECT_ERR);
break;
case JDBC_TL_CP_CHRSET:
/*
** !!!!! FIX-ME !!!!!
** Bootstrapping character set will fail if DBMS
** character set and driver default encoding are
** not minimally compatible.
*/
{
byte ba[] = new byte[param_len];
if (in.readBytes(ba, 0, param_len) == param_len) {
try {
cs = new String(ba, "US-ASCII");
} catch (Exception ex) {
if (trace.enabled(1)) trace.write(title + ": TL CP CHARSET: " + ex.toString());
throw EdbcEx.get(E_IO0001_CONNECT_ERR);
}
} else throw EdbcEx.get(E_IO0001_CONNECT_ERR);
}
break;
case JDBC_TL_CP_MSG:
if (info == null
|| param_len > info.length
|| in.readBytes(info, 0, param_len) != param_len)
throw EdbcEx.get(E_IO0001_CONNECT_ERR);
break;
default:
if (trace.enabled(1)) trace.write(title + ": TL CR param ID " + param_id);
throw EdbcEx.get(E_IO0001_CONNECT_ERR);
}
}
if (in.avail() > 0) throw EdbcEx.get(E_IO0001_CONNECT_ERR);
/*
** Validate message parameters.
*/
if (tl_proto < JDBC_TL_PROTO_1
|| tl_proto > JDBC_TL_DFLT_PROTO
|| size < JDBC_TL_PKT_MIN
|| size > JDBC_TL_PKT_MAX) {
if (trace.enabled(1))
trace.write(title + ": invalid TL parameter: protocol " + tl_proto + ", size " + size);
throw EdbcEx.get(E_IO0001_CONNECT_ERR);
}
try {
char_set = CharSet.getCharSet(cs);
} catch (Exception ex) {
if (trace.enabled(1)) trace.write(title + ": incompatible character set: " + cs);
throw EdbcEx.get(E_IO0001_CONNECT_ERR);
}
} catch (EdbcEx ex) {
if (trace.enabled(1)) trace.write(title + ": error negotiating parameters");
disconnect();
throw ex;
}
/*
** We initialized with minimum buffer size, then requested
** maximum size for the connection. If the server accepts
** anything more than minimum, adjust the buffers accordingly.
*/
if (size != JDBC_TL_PKT_MIN) setBuffSize(1 << size);
if (trace.enabled(3)) {
trace.write(title + ": TL connection parameters negotiated");
trace.write(" TL protocol level : " + tl_proto);
trace.write(" TL buffer size : " + (1 << size));
trace.write(" Character encoding: " + cs + " => " + char_set);
}
} // DbConnIn