Move to kernel style SPDX license identifiers

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

/*
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (C) 2016 EfficiOS Inc.
 * Copyright (C) 2016 Alexandre Montplaisir <alexmonthy@efficios.com>
 */

package org.lttng.ust.agent.client;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

/**
 * Session daemon command indicating to the Java agent that an
 * application-specific context was enabled in the tracing session.
 *
 * @author Alexandre Montplaisir
 */
class SessiondEnableAppContextCommand extends SessiondCommand {

	private final String retrieverName;
	private final String contextName;

	private final boolean commandIsValid;

	public SessiondEnableAppContextCommand(byte[] data) {
		if (data == null) {
			throw new IllegalArgumentException();
		}
		ByteBuffer buf = ByteBuffer.wrap(data);
		buf.order(ByteOrder.BIG_ENDIAN);

		/*
		 * The buffer contains the retriever name first, followed by the
		 * context's name.
		 */
		retrieverName = readNextString(buf);
		contextName = readNextString(buf);

		/* If any of these strings were null then the command was invalid */
		commandIsValid = ((retrieverName != null) && (contextName != null));
	}

	@Override
	public LttngAgentResponse execute(ILttngTcpClientListener agent) {
		if (!commandIsValid) {
			return LttngAgentResponse.FAILURE_RESPONSE;
		}

		boolean success = agent.appContextEnabled(retrieverName, contextName);
		return (success ? LttngAgentResponse.SUCESS_RESPONSE : LttngAgentResponse.FAILURE_RESPONSE);
	}
}