Turn ILttngAgentResponse into an abstract class

[lttng-ust.git] / liblttng-ust-java-agent / java / lttng-ust-agent-common / org / lttng / ust / agent / client / LttngAgentResponse.java

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngAgentResponse.java b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngAgentResponse.java
new file mode 100644 (file)
index 0000000..3c5a27e
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+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngAgentResponse.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
+ * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+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;
+
+       /**
+        * Return codes used in agent responses, to indicate success or different
+        * types of failures of the commands.
+        */
+       protected enum ReturnCode {
+
+               CODE_SUCCESS_CMD(1),
+               CODE_INVALID_CMD(2),
+               CODE_UNK_LOGGER_NAME(3);
+
+               private int code;
+
+               private ReturnCode(int c) {
+                       code = c;
+               }
+
+               public int getCode() {
+                       return code;
+               }
+       }
+
+       /**
+        * 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;
+       }
+
+       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;
+               }
+       };
+}