Small refactor of the Java agent's TCP client

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

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondCommandHeader.java b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondCommandHeader.java
new file mode 100644 (file)
index 0000000..1ce6502
--- /dev/null
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/SessiondCommandHeader.java
@@ -0,0 +1,59 @@
+/*
+ * 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;
+
+import org.lttng.ust.agent.client.ISessiondCommand.CommandType;
+
+/**
+ * Header of session daemon commands.
+ *
+ * @author Alexandre Montplaisir
+ * @author David Goulet
+ */
+class SessiondCommandHeader {
+
+       /** ABI size of command header. */
+       public static final int HEADER_SIZE = 16;
+
+       /** Payload size in bytes following this header. */
+       private final long dataSize;
+
+       /** Command type. */
+       private final CommandType cmd;
+
+       public SessiondCommandHeader(byte[] data) {
+               ByteBuffer buf = ByteBuffer.wrap(data);
+               buf.order(ByteOrder.BIG_ENDIAN);
+
+               dataSize = buf.getLong();
+               cmd = CommandType.values()[buf.getInt() - 1];
+               buf.getInt(); // command version, currently unused
+       }
+
+       public long getDataSize() {
+               return dataSize;
+       }
+
+       public CommandType getCommandType() {
+               return cmd;
+       }
+}