git.lttng.org Git - lttng-ust.git/blob

   1 /*
   2  * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
   3  * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
   4  *
   5  * This library is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This library is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  12  * for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public License
  15  * along with this library; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 package org.lttng.ust.agent.client;
  20
  21 import java.nio.ByteBuffer;
  22 import java.nio.ByteOrder;
  23
  24 import org.lttng.ust.agent.client.SessiondCommand.CommandType;
  25
  26 /**
  27  * Header of session daemon commands.
  28  *
  29  * @author Alexandre Montplaisir
  30  * @author David Goulet
  31  */
  32 class SessiondCommandHeader {
  33
  34         /** ABI size of command header. */
  35         public static final int HEADER_SIZE = 16;
  36
  37         /** Payload size in bytes following this header. */
  38         private final long dataSize;
  39
  40         /** Command type. */
  41         private final CommandType cmd;
  42
  43         public SessiondCommandHeader(byte[] data) {
  44                 ByteBuffer buf = ByteBuffer.wrap(data);
  45                 buf.order(ByteOrder.BIG_ENDIAN);
  46
  47                 dataSize = buf.getLong();
  48                 cmd = CommandType.values()[buf.getInt() - 1];
  49                 buf.getInt(); // command version, currently unused
  50         }
  51
  52         public long getDataSize() {
  53                 return dataSize;
  54         }
  55
  56         public CommandType getCommandType() {
  57                 return cmd;
  58         }
  59 }