| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-only |
| 3 | * |
| 4 | * Copyright (C) 2015-2022 EfficiOS Inc. |
| 5 | * Copyright (C) 2015 Alexandre Montplaisir <alexmonthy@efficios.com> |
| 6 | * Copyright (C) 2014 Christian Babeux <christian.babeux@efficios.com> |
| 7 | */ |
| 8 | |
| 9 | package org.lttng.ust.agent.log4j2; |
| 10 | |
| 11 | import java.io.IOException; |
| 12 | import java.util.Collection; |
| 13 | import java.util.Map; |
| 14 | import java.util.Map.Entry; |
| 15 | import java.util.concurrent.TimeUnit; |
| 16 | import java.util.concurrent.atomic.AtomicLong; |
| 17 | |
| 18 | import org.apache.logging.log4j.core.Appender; |
| 19 | import org.apache.logging.log4j.core.Core; |
| 20 | import org.apache.logging.log4j.core.Filter; |
| 21 | import org.apache.logging.log4j.core.LogEvent; |
| 22 | import org.apache.logging.log4j.core.appender.AbstractAppender; |
| 23 | import org.apache.logging.log4j.core.config.Property; |
| 24 | import org.apache.logging.log4j.core.config.plugins.Plugin; |
| 25 | import org.apache.logging.log4j.core.config.plugins.PluginAttribute; |
| 26 | import org.apache.logging.log4j.core.config.plugins.PluginElement; |
| 27 | import org.apache.logging.log4j.core.config.plugins.PluginFactory; |
| 28 | import org.lttng.ust.agent.ILttngHandler; |
| 29 | import org.lttng.ust.agent.context.ContextInfoSerializer; |
| 30 | |
| 31 | /** |
| 32 | * LTTng-UST Log4j 2.x log handler. |
| 33 | * |
| 34 | * Applications can attach this appender to their |
| 35 | * {@link org.apache.log4j.Logger} to have it generate UST events from logging |
| 36 | * events received through the logger. |
| 37 | * |
| 38 | * It sends its events to UST via the JNI library "liblttng-ust-log4j-jni.so". |
| 39 | * Make sure this library is available before using this appender. |
| 40 | * |
| 41 | */ |
| 42 | @Plugin(name = LttngLogAppender.PLUGIN_NAME, category = Core.CATEGORY_NAME, elementType = Appender.ELEMENT_TYPE, printObject = false) |
| 43 | public final class LttngLogAppender extends AbstractAppender implements ILttngHandler { |
| 44 | |
| 45 | /** |
| 46 | * The name of the appender in the configuration. |
| 47 | */ |
| 48 | public static final String PLUGIN_NAME = "Lttng"; |
| 49 | |
| 50 | private static final String SHARED_OBJECT_NAME = "lttng-ust-log4j-jni"; |
| 51 | |
| 52 | /** |
| 53 | * Number of events logged (really sent through JNI) by this handler |
| 54 | */ |
| 55 | private final AtomicLong eventCount = new AtomicLong(0); |
| 56 | |
| 57 | private final LttngLog4j2Agent agent; |
| 58 | |
| 59 | /** |
| 60 | * Constructor |
| 61 | * |
| 62 | * @param name The name of the Appender. |
| 63 | * @param filter The Filter or null. |
| 64 | * @param ignoreExceptions If {@code "true"} (default) exceptions encountered |
| 65 | * when appending events are logged; otherwise they are |
| 66 | * propagated to the caller. |
| 67 | * |
| 68 | * @throws IOException This handler requires the lttng-ust-log4j-jni.so |
| 69 | * native library, through which it will send the |
| 70 | * trace events. This exception is thrown if this |
| 71 | * library cannot be found. |
| 72 | * @throws SecurityException We will forward any SecurityExcepion that may be |
| 73 | * thrown when trying to load the JNI library. |
| 74 | */ |
| 75 | protected LttngLogAppender(String name, Filter filter, boolean ignoreExceptions) |
| 76 | throws IOException, SecurityException { |
| 77 | |
| 78 | super(name, filter, null, ignoreExceptions, Property.EMPTY_ARRAY); |
| 79 | |
| 80 | /* Initialize LTTng UST tracer. */ |
| 81 | try { |
| 82 | System.loadLibrary(SHARED_OBJECT_NAME); // $NON-NLS-1$ |
| 83 | } catch (UnsatisfiedLinkError e) { |
| 84 | throw new IOException(e); |
| 85 | } |
| 86 | |
| 87 | /* Register to the relevant agent. */ |
| 88 | agent = LttngLog4j2Agent.getInstance(); |
| 89 | agent.registerHandler(this); |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Create an LttngLogAppender. |
| 94 | * |
| 95 | * @param name The name of the Appender, null returns null. |
| 96 | * @param ignoreExceptions If {@code "true"} (default) exceptions encountered |
| 97 | * when appending events are logged; otherwise they are |
| 98 | * propagated to the caller. |
| 99 | * @param filter The Filter or null. |
| 100 | * |
| 101 | * @return A new LttngLogAppender, null if the name was null. |
| 102 | * |
| 103 | * @throws IOException This handler requires the lttng-ust-log4j-jni.so |
| 104 | * native library, through which it will send the |
| 105 | * trace events. This exception is thrown if this |
| 106 | * library cannot be found. |
| 107 | * @throws SecurityException We will forward any SecurityExcepion that may be |
| 108 | * thrown when trying to load the JNI library. |
| 109 | */ |
| 110 | @PluginFactory |
| 111 | public static LttngLogAppender createAppender(@PluginAttribute("name") String name, |
| 112 | @PluginAttribute("ignoreExceptions") Boolean ignoreExceptions, @PluginElement("Filters") Filter filter) |
| 113 | throws IOException, SecurityException { |
| 114 | |
| 115 | if (name == null) { |
| 116 | LOGGER.error("No name provided for LttngLogAppender"); |
| 117 | return null; |
| 118 | } |
| 119 | |
| 120 | if (ignoreExceptions == null) { |
| 121 | ignoreExceptions = true; |
| 122 | } |
| 123 | |
| 124 | return new LttngLogAppender(name, filter, ignoreExceptions); |
| 125 | } |
| 126 | |
| 127 | @Override |
| 128 | public synchronized void close() { |
| 129 | agent.unregisterHandler(this); |
| 130 | } |
| 131 | |
| 132 | @Override |
| 133 | public void stop() { |
| 134 | close(); |
| 135 | super.stop(); |
| 136 | |
| 137 | getStatusLogger().debug("Appender Lttng stopped"); |
| 138 | } |
| 139 | |
| 140 | @Override |
| 141 | public boolean stop(final long timeout, final TimeUnit timeUnit) { |
| 142 | close(); |
| 143 | boolean status = super.stop(timeout, timeUnit); |
| 144 | |
| 145 | getStatusLogger().debug("Appender Lttng stopped with status " + status); |
| 146 | |
| 147 | return status; |
| 148 | } |
| 149 | |
| 150 | /** |
| 151 | * Get the number of events logged by this handler so far. This means the number |
| 152 | * of events actually sent through JNI to UST. |
| 153 | * |
| 154 | * @return The number of events logged so far |
| 155 | */ |
| 156 | @Override |
| 157 | public long getEventCount() { |
| 158 | return eventCount.get(); |
| 159 | } |
| 160 | |
| 161 | @Override |
| 162 | public void append(LogEvent event) { |
| 163 | /* |
| 164 | * Check if the current message should be logged, according to the UST session |
| 165 | * settings. |
| 166 | */ |
| 167 | if (!agent.isEventEnabled(event.getLoggerName())) { |
| 168 | return; |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * Default values if the StackTraceElement is null. |
| 173 | */ |
| 174 | String classname = ""; |
| 175 | String methodname = ""; |
| 176 | String filename = ""; |
| 177 | int line = -1; |
| 178 | |
| 179 | StackTraceElement ste = event.getSource(); |
| 180 | if (ste != null) { |
| 181 | classname = ste.getClassName(); |
| 182 | methodname = ste.getMethodName(); |
| 183 | filename = ste.getFileName(); |
| 184 | line = ste.getLineNumber(); |
| 185 | } |
| 186 | |
| 187 | /* Retrieve all the requested context information we can find. */ |
| 188 | Collection<Entry<String, Map<String, Integer>>> enabledContexts = agent.getEnabledAppContexts(); |
| 189 | ContextInfoSerializer.SerializedContexts contextInfo = ContextInfoSerializer |
| 190 | .queryAndSerializeRequestedContexts(enabledContexts); |
| 191 | |
| 192 | eventCount.incrementAndGet(); |
| 193 | |
| 194 | LttngLog4j2Api.tracepointWithContext(event.getMessage().getFormattedMessage(), event.getLoggerName(), classname, |
| 195 | methodname, filename, line, event.getTimeMillis(), event.getLevel().intLevel(), event.getThreadName(), |
| 196 | contextInfo.getEntriesArray(), contextInfo.getStringsArray()); |
| 197 | } |
| 198 | } |