Move to kernel style SPDX license identifiers

[lttng-ust.git] / liblttng-ust-java-agent / java / lttng-ust-agent-jul / org / lttng / ust / agent / jul / LttngJulAgent.java

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-jul/org/lttng/ust/agent/jul/LttngJulAgent.java b/liblttng-ust-java-agent/java/lttng-ust-agent-jul/org/lttng/ust/agent/jul/LttngJulAgent.java
index fa92f64541b04788af12015bc3fa8d30343466d9..99c5fde0cc4b5fb2cc2bb8ca55d4c7a14c81aedb 100644 (file)
--- a/liblttng-ust-java-agent/java/lttng-ust-agent-jul/org/lttng/ust/agent/jul/LttngJulAgent.java
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-jul/org/lttng/ust/agent/jul/LttngJulAgent.java
@@ -1,22 +1,21 @@
 /*
- * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
+ * SPDX-License-Identifier: LGPL-2.1-only
  *
- * 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
+ * Copyright (C) 2015 EfficiOS Inc.
+ * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com>
  */
 
 package org.lttng.ust.agent.jul;
 
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.logging.Handler;
+import java.util.logging.LogManager;
+import java.util.logging.Logger;
+
 import org.lttng.ust.agent.AbstractLttngAgent;
 
 /**
@@ -39,4 +38,54 @@ class LttngJulAgent extends AbstractLttngAgent<LttngLogHandler> {
                return instance;
        }
 
+       @Override
+       public Collection<String> listAvailableEvents() {
+               Set<String> ret = new TreeSet<String>();
+
+               List<String> loggersNames = Collections.list(LogManager.getLogManager().getLoggerNames());
+               for (String name : loggersNames) {
+                       /*
+                        * Skip the root logger. An empty string is not a valid event name
+                        * in LTTng.
+                        */
+                       if (name.equals("") || name.equals("global")) {
+                               continue;
+                       }
+
+                       /*
+                        * Check if that logger has at least one LTTng JUL handler attached.
+                        */
+                       Logger logger = Logger.getLogger(name);
+                       if (hasLttngHandlerAttached(logger)) {
+                               ret.add(name);
+                       }
+               }
+
+               return ret;
+       }
+
+       private static boolean hasLttngHandlerAttached(Logger logger) {
+               for (Handler handler : logger.getHandlers()) {
+                       if (handler instanceof LttngLogHandler) {
+                               return true;
+                       }
+               }
+
+               /*
+                * A parent logger, if any, may be connected to an LTTng handler. In
+                * this case, we will want to include this child logger in the output,
+                * since it will be accessible by LTTng.
+                */
+               Logger parent = logger.getParent();
+               if (parent != null) {
+                       return hasLttngHandlerAttached(parent);
+               }
+
+               /*
+                * We have reached the root logger and have not found any LTTng handler,
+                * this event will not be accessible.
+                */
+               return false;
+       }
+
 }