/*
* Copyright (c) 1998, 2003, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
package com.sun.tools.jdi;
import com.sun.jdi.*;
import java.io.IOException;
public class Packet extends Object {
public final static short NoFlags = 0x0;
public final static short Reply = 0x80;
public final static short ReplyNoError = 0x0;
static int uID = 1;
final static byte[] nullData = new byte[0];
// Note! flags, cmdSet, and cmd are all byte values.
// We represent them as shorts to make them easier
// to work with.
int id;
short flags;
short cmdSet;
short cmd;
short errorCode;
byte[] data;
volatile boolean replied = false;
/**
* Return byte representation of the packet
*/
public byte[] toByteArray() {
int len = data.length + 11;
byte b[] = new byte[len];
b[0] = (byte)((len >>> 24) & 0xff);
b[1] = (byte)((len >>> 16) & 0xff);
b[2] = (byte)((len >>> 8) & 0xff);
b[3] = (byte)((len >>> 0) & 0xff);
b[4] = (byte)((id >>> 24) & 0xff);
b[5] = (byte)((id >>> 16) & 0xff);
b[6] = (byte)((id >>> 8) & 0xff);
b[7] = (byte)((id >>> 0) & 0xff);
b[8] = (byte)flags;
if ((flags & Packet.Reply) == 0) {
b[9] = (byte)cmdSet;
b[10] = (byte)cmd;
} else {
b[9] = (byte)((errorCode >>> 8) & 0xff);
b[10] = (byte)((errorCode >>> 0) & 0xff);
}
if (data.length > 0) {
System.arraycopy(data, 0, b, 11, data.length);
}
return b;
}
/**
* Create a packet from its byte array representation
*/
public static Packet fromByteArray(byte b[]) throws IOException {
if (b.length < 11) {
throw new IOException("packet is insufficient size");
}
int b0 = b[0] & 0xff;
int b1 = b[1] & 0xff;
int b2 = b[2] & 0xff;
int b3 = b[3] & 0xff;
int len = ((b0 << 24) | (b1 << 16) | (b2 << 8) | (b3 << 0));
if (len != b.length) {
throw new IOException("length size mis-match");
}
int b4 = b[4] & 0xff;
int b5 = b[5] & 0xff;
int b6 = b[6] & 0xff;
int b7 = b[7] & 0xff;
Packet p = new Packet();
p.id = ((b4 << 24) | (b5 << 16) | (b6 << 8) | (b7 << 0));
p.flags = (short)(b[8] & 0xff);
if ((p.flags & Packet.Reply) == 0) {
p.cmdSet = (short)(b[9] & 0xff);
p.cmd = (short)(b[10] & 0xff);
} else {
short b9 = (short)(b[9] & 0xff);
short b10 = (short)(b[10] & 0xff);
p.errorCode = (short)((b9 << 8) + (b10 << 0));
}
p.data = new byte[b.length - 11];
System.arraycopy(b, 11, p.data, 0, p.data.length);
return p;
}
Packet()
{
id = uniqID();
flags = NoFlags;
data = nullData;
}
static synchronized private int uniqID()
{
/*
* JDWP spec does not require this id to be sequential and
* increasing, but our implementation does. See
* VirtualMachine.notifySuspend, for example.
*/
return uID++;
}
}