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

   1 /*
   2  * Copyright (C) 2016 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 package org.lttng.ust.agent.client;
  19
  20 import java.nio.ByteBuffer;
  21 import java.nio.ByteOrder;
  22
  23 /**
  24  * Session daemon command indicating to the Java agent that an
  25  * application-specific context was enabled in the tracing session.
  26  *
  27  * @author Alexandre Montplaisir
  28  */
  29 class SessiondEnableAppContextCommand extends SessiondCommand {
  30
  31         private final String retrieverName;
  32         private final String contextName;
  33
  34         private final boolean commandIsValid;
  35
  36         public SessiondEnableAppContextCommand(byte[] data) {
  37                 if (data == null) {
  38                         throw new IllegalArgumentException();
  39                 }
  40                 ByteBuffer buf = ByteBuffer.wrap(data);
  41                 buf.order(ByteOrder.BIG_ENDIAN);
  42
  43                 /*
  44                  * The buffer contains the retriever name first, followed by the
  45                  * context's name.
  46                  */
  47                 retrieverName = readNextString(buf);
  48                 contextName = readNextString(buf);
  49
  50                 /* If any of these strings were null then the command was invalid */
  51                 commandIsValid = ((retrieverName != null) && (contextName != null));
  52         }
  53
  54         @Override
  55         public LttngAgentResponse execute(ILttngTcpClientListener agent) {
  56                 if (!commandIsValid) {
  57                         return LttngAgentResponse.FAILURE_RESPONSE;
  58                 }
  59
  60                 boolean success = agent.appContextEnabled(retrieverName, contextName);
  61                 return (success ? LttngAgentResponse.SUCESS_RESPONSE : LttngAgentResponse.FAILURE_RESPONSE);
  62         }
  63 }