--- /dev/null
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2015 EfficiOS Inc.
+ * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com>
+ * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
+ */
+
+package org.lttng.ust.agent.client;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+/**
+ * Interface for all response messages sent from the Java agent to the sessiond
+ * daemon. Normally sent after a command coming from the session daemon was
+ * executed.
+ *
+ * @author Alexandre Montplaisir
+ */
+abstract class LttngAgentResponse {
+
+ private static final int INT_SIZE = 4;
+
+ public static final LttngAgentResponse SUCESS_RESPONSE = new LttngAgentResponse() {
+ @Override
+ public ReturnCode getReturnCode() {
+ return ReturnCode.CODE_SUCCESS_CMD;
+ }
+ };
+
+ public static final LttngAgentResponse FAILURE_RESPONSE = new LttngAgentResponse() {
+ @Override
+ public ReturnCode getReturnCode() {
+ return ReturnCode.CODE_INVALID_CMD;
+ }
+ };
+
+ /**
+ * Return codes used in agent responses, to indicate success or different
+ * types of failures of the commands.
+ */
+ protected enum ReturnCode {
+
+ CODE_SUCCESS_CMD(1, "sucess"),
+ CODE_INVALID_CMD(2, "invalid"),
+ CODE_UNKNOWN_LOGGER_NAME(3, "unknown logger name");
+
+ private final int code;
+ private final String toString;
+
+ private ReturnCode(int c, String str) {
+ code = c;
+ toString = str;
+ }
+
+ public int getCode() {
+ return code;
+ }
+
+ /**
+ * Mainly used for debugging. The strings are not sent through the
+ * socket.
+ */
+ @Override
+ public String toString() {
+ return toString;
+ }
+ }
+
+ /**
+ * Get the {@link ReturnCode} that goes with this response. It is expected
+ * by the session daemon, but some commands may require more than this
+ * in their response.
+ *
+ * @return The return code
+ */
+ public abstract ReturnCode getReturnCode();
+
+ /**
+ * Gets a byte array of the response so that it may be streamed.
+ *
+ * @return The byte array of the response
+ */
+ public byte[] getBytes() {
+ byte data[] = new byte[INT_SIZE];
+ ByteBuffer buf = ByteBuffer.wrap(data);
+ buf.order(ByteOrder.BIG_ENDIAN);
+ buf.putInt(getReturnCode().getCode());
+ return data;
+ }
+
+ @Override
+ public String toString() {
+ return "LttngAgentResponse["
+ + "code=" + getReturnCode().getCode()
+ + ", " + getReturnCode().toString()
+ + "]";
+ }
+}