1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache license, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the license for the specific language governing permissions and
15 * limitations under the license.
16 */
17 package org.apache.logging.log4j.core.util;
18
19 import java.nio.charset.Charset;
20 import java.nio.charset.StandardCharsets;
21
22 import org.apache.logging.log4j.util.PropertiesUtil;
23
24 /**
25 * Log4j Constants.
26 */
27 public final class Constants {
28
29 /**
30 * Name of the system property to use to identify the LogEvent factory.
31 */
32 public static final String LOG4J_LOG_EVENT_FACTORY = "Log4jLogEventFactory";
33
34 /**
35 * Name of the system property to use to identify the ContextSelector Class.
36 */
37 public static final String LOG4J_CONTEXT_SELECTOR = "Log4jContextSelector";
38
39 /**
40 * Property name for the default status (internal log4j logging) level to use if not specified in configuration.
41 */
42 public static final String LOG4J_DEFAULT_STATUS_LEVEL = "Log4jDefaultStatusLevel";
43
44 /**
45 * JNDI context name string literal.
46 */
47 public static final String JNDI_CONTEXT_NAME = "java:comp/env/log4j/context-name";
48
49 /**
50 * Line separator.
51 */
52 public static final String LINE_SEPARATOR = PropertiesUtil.getProperties().getStringProperty("line.separator",
53 "\n");
54
55 /**
56 * Number of milliseconds in a second.
57 */
58 public static final int MILLIS_IN_SECONDS = 1000;
59
60 /**
61 * Equivalent to StandardCharsets.UTF_8.
62 *
63 * @deprecated Use {@link StandardCharsets#UTF_8}. Will be removed in 2.5.
64 */
65 @Deprecated
66 public static final Charset UTF_8 = StandardCharsets.UTF_8;
67
68 /**
69 * Supports user request LOG4J2-898 to have the option to format a message in the background thread.
70 */
71 public static final boolean FORMAT_MESSAGES_IN_BACKGROUND = PropertiesUtil.getProperties().getBooleanProperty(
72 "log4j.format.msg.async", false);
73
74 /**
75 * {@code true} if we think we are running in a web container, based on the boolean value of system property
76 * "log4j2.is.webapp", or (if this system property is not set) whether the {@code javax.servlet.Servlet} class
77 * is present in the classpath.
78 */
79 public static final boolean IS_WEB_APP = PropertiesUtil.getProperties().getBooleanProperty(
80 "log4j2.is.webapp", Loader.isClassAvailable("javax.servlet.Servlet"));
81
82 /**
83 * Kill switch for object pooling in ThreadLocals that enables much of the LOG4J2-1270 no-GC behaviour.
84 * <p>
85 * {@code True} for non-{@link #IS_WEB_APP web apps}, disable by setting system property
86 * "log4j2.enable.threadlocals" to "false".
87 *
88 * @since 2.6
89 */
90 public static final boolean ENABLE_THREADLOCALS = !IS_WEB_APP && PropertiesUtil.getProperties().getBooleanProperty(
91 "log4j2.enable.threadlocals", true);
92
93 /**
94 * Kill switch for garbage-free Layout behaviour that encodes LogEvents directly into
95 * {@link org.apache.logging.log4j.core.layout.ByteBufferDestination}s without creating intermediate temporary
96 * Objects.
97 * <p>
98 * {@code True} by default iff all loggers are asynchronous because system property
99 * {@code Log4jContextSelector} is set to {@code org.apache.logging.log4j.core.async.AsyncLoggerContextSelector}.
100 * Disable by setting system property "log4j2.enable.direct.encoders" to "false".
101 *
102 * @since 2.6
103 */
104 public static final boolean ENABLE_DIRECT_ENCODERS = PropertiesUtil.getProperties().getBooleanProperty(
105 "log4j2.enable.direct.encoders", true); // enable GC-free text encoding by default
106 // the alternative is to enable GC-free encoding only by default only when using all-async loggers:
107 //AsyncLoggerContextSelector.class.getName().equals(PropertiesUtil.getProperties().getStringProperty(LOG4J_CONTEXT_SELECTOR)));
108
109 /**
110 * Initial StringBuilder size used in RingBuffer LogEvents to store the contents of reusable Messages.
111 * <p>
112 * The default value is {@value}, users can override with system property "log4j.initialReusableMsgSize".
113 * </p>
114 * @since 2.6
115 */
116 public static final int INITIAL_REUSABLE_MESSAGE_SIZE = size("log4j.initialReusableMsgSize", 128);
117
118 /**
119 * Maximum size of the StringBuilders used in RingBuffer LogEvents to store the contents of reusable Messages.
120 * After a large message has been delivered to the appenders, the StringBuilder is trimmed to this size.
121 * <p>
122 * The default value is {@value}, which allows the StringBuilder to resize three times from its initial size.
123 * Users can override with system property "log4j.maxReusableMsgSize".
124 * </p>
125 * @since 2.6
126 */
127 public static final int MAX_REUSABLE_MESSAGE_SIZE = size("log4j.maxReusableMsgSize", (128 * 2 + 2) * 2 + 2);
128
129 /**
130 * Size of CharBuffers used by text encoders.
131 * <p>
132 * The default value is {@value}, users can override with system property "log4j.encoder.charBufferSize".
133 * </p>
134 * @since 2.6
135 */
136 public static final int ENCODER_CHAR_BUFFER_SIZE = size("log4j.encoder.charBufferSize", 2048);
137
138 /**
139 * Default size of ByteBuffers used to encode LogEvents without allocating temporary objects.
140 * <p>
141 * The default value is {@value}, users can override with system property "log4j.encoder.byteBufferSize".
142 * </p>
143 * @see org.apache.logging.log4j.core.layout.ByteBufferDestination
144 * @since 2.6
145 */
146 public static final int ENCODER_BYTE_BUFFER_SIZE = size("log4j.encoder.byteBufferSize", 8 * 1024);
147
148
149 private static int size(final String property, final int defaultValue) {
150 return PropertiesUtil.getProperties().getIntegerProperty(property, defaultValue);
151 }
152
153 /**
154 * Prevent class instantiation.
155 */
156 private Constants() {
157 }
158 }