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

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2016 EfficiOS Inc.
   5  * Copyright (C) 2016 Alexandre Montplaisir <alexmonthy@efficios.com>
   6  */
   7
   8 package org.lttng.ust.agent.client;
   9
  10 import java.nio.ByteBuffer;
  11 import java.nio.ByteOrder;
  12
  13 /**
  14  * Session daemon command indicating to the Java agent that an
  15  * application-specific context was enabled in the tracing session.
  16  *
  17  * @author Alexandre Montplaisir
  18  */
  19 class SessiondEnableAppContextCommand extends SessiondCommand {
  20
  21         private final String retrieverName;
  22         private final String contextName;
  23
  24         private final boolean commandIsValid;
  25
  26         public SessiondEnableAppContextCommand(byte[] data) {
  27                 if (data == null) {
  28                         throw new IllegalArgumentException();
  29                 }
  30                 ByteBuffer buf = ByteBuffer.wrap(data);
  31                 buf.order(ByteOrder.BIG_ENDIAN);
  32
  33                 /*
  34                  * The buffer contains the retriever name first, followed by the
  35                  * context's name.
  36                  */
  37                 retrieverName = readNextString(buf);
  38                 contextName = readNextString(buf);
  39
  40                 /* If any of these strings were null then the command was invalid */
  41                 commandIsValid = ((retrieverName != null) && (contextName != null));
  42         }
  43
  44         @Override
  45         public LttngAgentResponse execute(ILttngTcpClientListener agent) {
  46                 if (!commandIsValid) {
  47                         return LttngAgentResponse.FAILURE_RESPONSE;
  48                 }
  49
  50                 boolean success = agent.appContextEnabled(retrieverName, contextName);
  51                 return (success ? LttngAgentResponse.SUCESS_RESPONSE : LttngAgentResponse.FAILURE_RESPONSE);
  52         }
  53 }