Refactor liblttng-ust-jul in liblttng-ust-agent

[lttng-ust.git] / liblttng-ust-java-agent / java / org / lttng / ust / agent / log4j / LTTngLog4j.java

diff --git a/liblttng-ust-java-agent/java/org/lttng/ust/agent/log4j/LTTngLog4j.java b/liblttng-ust-java-agent/java/org/lttng/ust/agent/log4j/LTTngLog4j.java
new file mode 100644 (file)
index 0000000..065b163
--- /dev/null
+++ b/liblttng-ust-java-agent/java/org/lttng/ust/agent/log4j/LTTngLog4j.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2014 - Christian Babeux <christian.babeux@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.log4j;
+
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.Vector;
+
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+
+import org.lttng.ust.agent.LogFrameworkSkeleton;
+
+public class LTTngLog4j extends LogFrameworkSkeleton {
+
+       private LTTngLogAppender appender;
+       private Boolean attached;
+
+       public LTTngLog4j(Boolean isRoot) {
+               super();
+               this.appender = new LTTngLogAppender(isRoot);
+               this.attached = false;
+       }
+
+       @Override
+       public Boolean enableLogger(String name) {
+               if(!super.enableLogger(name)) {
+                       return false;
+               }
+
+               /* The first enable of any event triggers the attachment to the root logger */
+               if (getEventCount() == 1 && !this.attached) {
+                       attachToRootLogger();
+               }
+
+               return true;
+       }
+
+       @Override
+       public Boolean disableLogger(String name) {
+               if(!super.disableLogger(name)) {
+                       return false;
+               }
+
+               /* Detach from the root logger when the event counts reach zero */
+               if (getEventCount() == 0 && this.attached) {
+                       detachFromRootLogger();
+               }
+
+               return true;
+       }
+
+       @Override
+       public Iterator<String> listLoggers() {
+               Vector<String> logs = new Vector<String>();
+               for (Enumeration loggers = LogManager.getCurrentLoggers(); loggers.hasMoreElements(); ) {
+                       Logger logger = (Logger) loggers.nextElement();
+                       String name = logger.getName();
+                       logs.add(name);
+               }
+
+               return logs.iterator();
+       }
+
+       @Override
+       public Boolean isRoot() {
+               return appender.isRoot();
+       }
+
+       @Override
+       public void reset() {
+               super.reset();
+               detachFromRootLogger();
+       }
+
+       private void attachToRootLogger() {
+               if (this.attached) {
+                       return;
+               }
+
+               Logger logger = Logger.getRootLogger();
+               logger.addAppender(this.appender);
+               this.attached = true;
+       }
+
+       private void detachFromRootLogger() {
+               if (!this.attached) {
+                       return;
+               }
+
+               Logger logger = Logger.getRootLogger();
+               logger.removeAppender(this.appender);
+               this.attached = false;
+       }
+}