liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondEnableEventCommand.java

   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 /**
  25  * Session daemon command indicating to the Java agent that some events were
  26  * enabled in the tracing session.
  27  *
  28  * @author Alexandre Montplaisir
  29  * @author David Goulet
  30  */
  31 class SessiondEnableEventCommand implements ISessiondCommand {
  32
  33         private static final int INT_SIZE = 4;
  34
  35         /** Event name to enable in the tracing session */
  36         private final String eventName;
  37
  38         public SessiondEnableEventCommand(byte[] data) {
  39                 if (data == null) {
  40                         throw new IllegalArgumentException();
  41                 }
  42                 int dataOffset = INT_SIZE * 2;
  43
  44                 ByteBuffer buf = ByteBuffer.wrap(data);
  45                 buf.order(ByteOrder.LITTLE_ENDIAN);
  46                 buf.getInt(); // logLevel, currently unused
  47                 buf.getInt(); // logLevelType, currently unused
  48                 eventName = new String(data, dataOffset, data.length - dataOffset).trim();
  49         }
  50
  51         @Override
  52         public LttngAgentResponse execute(ILttngTcpClientListener agent) {
  53                 boolean success = agent.eventEnabled(this.eventName);
  54                 return (success ? LttngAgentResponse.SUCESS_RESPONSE : LttngAgentResponse.FAILURE_RESPONSE);
  55         }
  56 }