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 import org.lttng.ust.agent.session.EventRule;
  25 import org.lttng.ust.agent.session.LogLevelSelector;
  26
  27 /**
  28  * Session daemon command indicating to the Java agent that some events were
  29  * enabled in the tracing session.
  30  *
  31  * @author Alexandre Montplaisir
  32  * @author David Goulet
  33  */
  34 class SessiondEnableEventCommand extends SessiondCommand {
  35
  36         /** Fixed event name length. Value defined by the lttng agent protocol. */
  37         private static final int EVENT_NAME_LENGTH = 256;
  38
  39         private final boolean commandIsValid;
  40
  41         /* Parameters of the event rule being enabled */
  42         private final String eventName;
  43         private final LogLevelSelector logLevelFilter;
  44         private final String filterString;
  45
  46         public SessiondEnableEventCommand(byte[] data) {
  47                 if (data == null) {
  48                         throw new IllegalArgumentException();
  49                 }
  50                 ByteBuffer buf = ByteBuffer.wrap(data);
  51                 buf.order(ByteOrder.BIG_ENDIAN);
  52                 int logLevel = buf.getInt();
  53                 int logLevelType = buf.getInt();
  54                 logLevelFilter = new LogLevelSelector(logLevel, logLevelType);
  55
  56                 /* Read the event name */
  57                 byte[] eventNameBytes = new byte[EVENT_NAME_LENGTH];
  58                 buf.get(eventNameBytes);
  59                 eventName = new String(eventNameBytes, SESSIOND_PROTOCOL_CHARSET).trim();
  60
  61                 /* Read the filter string */
  62                 filterString = readNextString(buf);
  63
  64                 /* The command was invalid if the string could not be read correctly */
  65                 commandIsValid = (filterString != null);
  66         }
  67
  68         @Override
  69         public LttngAgentResponse execute(ILttngTcpClientListener agent) {
  70                 if (!commandIsValid) {
  71                         return LttngAgentResponse.FAILURE_RESPONSE;
  72                 }
  73
  74                 EventRule rule = new EventRule(eventName, logLevelFilter, filterString);
  75                 boolean success = agent.eventEnabled(rule);
  76                 return (success ? LttngAgentResponse.SUCESS_RESPONSE : LttngAgentResponse.FAILURE_RESPONSE);
  77         }
  78
  79         @Override
  80         public String toString() {
  81                 return "SessiondEnableEventCommand["
  82                                 + "eventName=" + eventName
  83                                 + ", logLevel=" + logLevelFilter.toString()
  84                                 + ", filterString=" + filterString
  85                                 +"]";
  86         }
  87 }