| /* |
| * Copyright (c) 1998, 2017, 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 |
| * questions. |
| */ |
| |
| package com.sun.tools.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++; |
| } |
| } |