src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngAgentResponse.java

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2015 EfficiOS Inc.
   5  * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com>
   6  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   7  */
   8
   9 package org.lttng.ust.agent.client;
  10
  11 import java.nio.ByteBuffer;
  12 import java.nio.ByteOrder;
  13
  14 /**
  15  * Interface for all response messages sent from the Java agent to the sessiond
  16  * daemon. Normally sent after a command coming from the session daemon was
  17  * executed.
  18  *
  19  * @author Alexandre Montplaisir
  20  */
  21 abstract class LttngAgentResponse {
  22
  23         private static final int INT_SIZE = 4;
  24
  25         public static final LttngAgentResponse SUCESS_RESPONSE = new LttngAgentResponse() {
  26                 @Override
  27                 public ReturnCode getReturnCode() {
  28                         return ReturnCode.CODE_SUCCESS_CMD;
  29                 }
  30         };
  31
  32         public static final LttngAgentResponse FAILURE_RESPONSE = new LttngAgentResponse() {
  33                 @Override
  34                 public ReturnCode getReturnCode() {
  35                         return ReturnCode.CODE_INVALID_CMD;
  36                 }
  37         };
  38
  39         /**
  40          * Return codes used in agent responses, to indicate success or different
  41          * types of failures of the commands.
  42          */
  43         protected enum ReturnCode {
  44
  45                 CODE_SUCCESS_CMD(1, "success"),
  46                 CODE_INVALID_CMD(2, "invalid"),
  47                 CODE_UNKNOWN_LOGGER_NAME(3, "unknown logger name");
  48
  49                 private final int code;
  50                 private final String toString;
  51
  52                 private ReturnCode(int c, String str) {
  53                         code = c;
  54                         toString = str;
  55                 }
  56
  57                 public int getCode() {
  58                         return code;
  59                 }
  60
  61                 /**
  62                  * Mainly used for debugging. The strings are not sent through the
  63                  * socket.
  64                  */
  65                 @Override
  66                 public String toString() {
  67                         return toString;
  68                 }
  69         }
  70
  71         /**
  72          * Get the {@link ReturnCode} that goes with this response. It is expected
  73          * by the session daemon, but some commands may require more than this
  74          * in their response.
  75          *
  76          * @return The return code
  77          */
  78         public abstract ReturnCode getReturnCode();
  79
  80         /**
  81          * Gets a byte array of the response so that it may be streamed.
  82          *
  83          * @return The byte array of the response
  84          */
  85         public byte[] getBytes() {
  86                 byte data[] = new byte[INT_SIZE];
  87                 ByteBuffer buf = ByteBuffer.wrap(data);
  88                 buf.order(ByteOrder.BIG_ENDIAN);
  89                 buf.putInt(getReturnCode().getCode());
  90                 return data;
  91         }
  92
  93         @Override
  94         public String toString() {
  95                 return "LttngAgentResponse["
  96                                 + "code=" + getReturnCode().getCode()
  97                                 + ", " + getReturnCode().toString()
  98                                 + "]";
  99         }
 100 }