--- /dev/null
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2015-2022 EfficiOS Inc.
+ * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com>
+ * Copyright (C) 2014 Christian Babeux <christian.babeux@efficios.com>
+ */
+
+package org.lttng.ust.agent.log4j2;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.logging.log4j.core.Appender;
+import org.apache.logging.log4j.core.Core;
+import org.apache.logging.log4j.core.Filter;
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.appender.AbstractAppender;
+import org.apache.logging.log4j.core.config.Property;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
+import org.apache.logging.log4j.core.config.plugins.PluginElement;
+import org.apache.logging.log4j.core.config.plugins.PluginFactory;
+import org.lttng.ust.agent.ILttngHandler;
+import org.lttng.ust.agent.context.ContextInfoSerializer;
+
+/**
+ * LTTng-UST Log4j 2.x log handler.
+ *
+ * Applications can attach this appender to their
+ * {@link org.apache.log4j.Logger} to have it generate UST events from logging
+ * events received through the logger.
+ *
+ * It sends its events to UST via the JNI library "liblttng-ust-log4j-jni.so".
+ * Make sure this library is available before using this appender.
+ *
+ */
+@Plugin(name = LttngLogAppender.PLUGIN_NAME, category = Core.CATEGORY_NAME, elementType = Appender.ELEMENT_TYPE, printObject = false)
+public final class LttngLogAppender extends AbstractAppender implements ILttngHandler {
+
+ /**
+ * The name of the appender in the configuration.
+ */
+ public static final String PLUGIN_NAME = "Lttng";
+
+ private static final String SHARED_OBJECT_NAME = "lttng-ust-log4j-jni";
+
+ /**
+ * Number of events logged (really sent through JNI) by this handler
+ */
+ private final AtomicLong eventCount = new AtomicLong(0);
+
+ private final LttngLog4j2Agent agent;
+
+ /**
+ * Constructor
+ *
+ * @param name The name of the Appender.
+ * @param filter The Filter or null.
+ * @param ignoreExceptions If {@code "true"} (default) exceptions encountered
+ * when appending events are logged; otherwise they are
+ * propagated to the caller.
+ *
+ * @throws IOException This handler requires the lttng-ust-log4j-jni.so
+ * native library, through which it will send the
+ * trace events. This exception is thrown if this
+ * library cannot be found.
+ * @throws SecurityException We will forward any SecurityExcepion that may be
+ * thrown when trying to load the JNI library.
+ */
+ protected LttngLogAppender(String name, Filter filter, boolean ignoreExceptions)
+ throws IOException, SecurityException {
+
+ super(name, filter, null, ignoreExceptions, Property.EMPTY_ARRAY);
+
+ /* Initialize LTTng UST tracer. */
+ try {
+ System.loadLibrary(SHARED_OBJECT_NAME); // $NON-NLS-1$
+ } catch (UnsatisfiedLinkError e) {
+ throw new IOException(e);
+ }
+
+ /* Register to the relevant agent. */
+ agent = LttngLog4j2Agent.getInstance();
+ agent.registerHandler(this);
+ }
+
+ /**
+ * Create an LttngLogAppender.
+ *
+ * @param name The name of the Appender, null returns null.
+ * @param ignoreExceptions If {@code "true"} (default) exceptions encountered
+ * when appending events are logged; otherwise they are
+ * propagated to the caller.
+ * @param filter The Filter or null.
+ *
+ * @return A new LttngLogAppender, null if the name was null.
+ *
+ * @throws IOException This handler requires the lttng-ust-log4j-jni.so
+ * native library, through which it will send the
+ * trace events. This exception is thrown if this
+ * library cannot be found.
+ * @throws SecurityException We will forward any SecurityExcepion that may be
+ * thrown when trying to load the JNI library.
+ */
+ @PluginFactory
+ public static LttngLogAppender createAppender(@PluginAttribute("name") String name,
+ @PluginAttribute("ignoreExceptions") Boolean ignoreExceptions, @PluginElement("Filters") Filter filter)
+ throws IOException, SecurityException {
+
+ if (name == null) {
+ LOGGER.error("No name provided for LttngLogAppender");
+ return null;
+ }
+
+ if (ignoreExceptions == null) {
+ ignoreExceptions = true;
+ }
+
+ return new LttngLogAppender(name, filter, ignoreExceptions);
+ }
+
+ @Override
+ public synchronized void close() {
+ agent.unregisterHandler(this);
+ }
+
+ @Override
+ public void stop() {
+ close();
+ super.stop();
+
+ getStatusLogger().debug("Appender Lttng stopped");
+ }
+
+ @Override
+ public boolean stop(final long timeout, final TimeUnit timeUnit) {
+ close();
+ boolean status = super.stop(timeout, timeUnit);
+
+ getStatusLogger().debug("Appender Lttng stopped with status " + status);
+
+ return status;
+ }
+
+ /**
+ * Get the number of events logged by this handler so far. This means the number
+ * of events actually sent through JNI to UST.
+ *
+ * @return The number of events logged so far
+ */
+ @Override
+ public long getEventCount() {
+ return eventCount.get();
+ }
+
+ @Override
+ public void append(LogEvent event) {
+ /*
+ * Check if the current message should be logged, according to the UST session
+ * settings.
+ */
+ if (!agent.isEventEnabled(event.getLoggerName())) {
+ return;
+ }
+
+ /*
+ * Default values if the StackTraceElement is null.
+ */
+ String classname = "";
+ String methodname = "";
+ String filename = "";
+ int line = -1;
+
+ StackTraceElement ste = event.getSource();
+ if (ste != null) {
+ classname = ste.getClassName();
+ methodname = ste.getMethodName();
+ filename = ste.getFileName();
+ line = ste.getLineNumber();
+ }
+
+ /* Retrieve all the requested context information we can find. */
+ Collection<Entry<String, Map<String, Integer>>> enabledContexts = agent.getEnabledAppContexts();
+ ContextInfoSerializer.SerializedContexts contextInfo = ContextInfoSerializer
+ .queryAndSerializeRequestedContexts(enabledContexts);
+
+ eventCount.incrementAndGet();
+
+ LttngLog4j2Api.tracepointWithContext(event.getMessage().getFormattedMessage(), event.getLoggerName(), classname,
+ methodname, filename, line, event.getTimeMillis(), event.getLevel().intLevel(), event.getThreadName(),
+ contextInfo.getEntriesArray(), contextInfo.getStringsArray());
+ }
+}
projects / lttng-ust.git / blobdiff