Fix: Include child loggers in the output of "lttng list"

[lttng-ust.git] / liblttng-ust-java-agent / java / lttng-ust-agent-log4j / org / lttng / ust / agent / log4j / LttngLog4jAgent.java

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java b/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java
index 6cb74f91b5516864c1cc35403a1e8ff525cdda38..7677e68ee66e2b2c20773e0675654d24e49f7f46 100644 (file)
--- a/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-log4j/org/lttng/ust/agent/log4j/LttngLog4jAgent.java
@@ -17,12 +17,14 @@
 
 package org.lttng.ust.agent.log4j;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
 
 import org.apache.log4j.Appender;
+import org.apache.log4j.Category;
 import org.apache.log4j.LogManager;
 import org.apache.log4j.Logger;
 import org.lttng.ust.agent.AbstractLttngAgent;
@@ -50,7 +52,7 @@ class LttngLog4jAgent extends AbstractLttngAgent<LttngLogAppender> {
 
        @Override
        public Collection<String> listAvailableEvents() {
-               List<String> ret = new ArrayList<String>();
+               Set<String> ret = new TreeSet<String>();
 
                @SuppressWarnings("unchecked")
                List<Logger> loggers = Collections.list(LogManager.getCurrentLoggers());
@@ -71,7 +73,7 @@ class LttngLog4jAgent extends AbstractLttngAgent<LttngLogAppender> {
                return ret;
        }
 
-       private static boolean hasLttngAppenderAttached(Logger logger) {
+       private static boolean hasLttngAppenderAttached(Category logger) {
                @SuppressWarnings("unchecked")
                List<Appender> appenders = Collections.list(logger.getAllAppenders());
                for (Appender appender : appenders) {
@@ -79,6 +81,22 @@ class LttngLog4jAgent extends AbstractLttngAgent<LttngLogAppender> {
                                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.
+                */
+               Category parent = logger.getParent();
+               if (parent != null) {
+                       return hasLttngAppenderAttached(parent);
+               }
+
+               /*
+                * We have reached the root logger and have not found any LTTng handler,
+                * this event will not be accessible.
+                */
                return false;
        }
+
 }