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 org.apache.logging.log4j.util.PropertiesUtil;
20
21 /**
22 * Log4j Constants.
23 */
24 public final class Constants {
25
26 /**
27 * Name of the system property to use to identify the LogEvent factory.
28 */
29 public static final String LOG4J_LOG_EVENT_FACTORY = "Log4jLogEventFactory";
30
31 /**
32 * Name of the system property to use to identify the ContextSelector Class.
33 */
34 public static final String LOG4J_CONTEXT_SELECTOR = "Log4jContextSelector";
35
36 /**
37 * Property name for the default status (internal log4j logging) level to use if not specified in configuration.
38 */
39 public static final String LOG4J_DEFAULT_STATUS_LEVEL = "Log4jDefaultStatusLevel";
40
41 /**
42 * JNDI context name string literal.
43 */
44 public static final String JNDI_CONTEXT_NAME = "java:comp/env/log4j/context-name";
45
46 /**
47 * Number of milliseconds in a second.
48 */
49 public static final int MILLIS_IN_SECONDS = 1000;
50
51 /**
52 * Supports user request LOG4J2-898 to have the option to format a message in the background thread.
53 */
54 public static final boolean FORMAT_MESSAGES_IN_BACKGROUND = PropertiesUtil.getProperties().getBooleanProperty(
55 "log4j.format.msg.async", false);
56
57 /**
58 * {@code true} if we think we are running in a web container, based on the boolean value of system property
59 * "log4j2.is.webapp", or (if this system property is not set) whether the {@code javax.servlet.Servlet} class
60 * is present in the classpath.
61 */
62 public static final boolean IS_WEB_APP = org.apache.logging.log4j.util.Constants.IS_WEB_APP;
63
64 /**
65 * Kill switch for object pooling in ThreadLocals that enables much of the LOG4J2-1270 no-GC behaviour.
66 * <p>
67 * {@code True} for non-{@link #IS_WEB_APP web apps}, disable by setting system property
68 * "log4j2.enable.threadlocals" to "false".
69 *
70 * @since 2.6
71 */
72 public static final boolean ENABLE_THREADLOCALS = org.apache.logging.log4j.util.Constants.ENABLE_THREADLOCALS;
73
74 /**
75 * Kill switch for garbage-free Layout behaviour that encodes LogEvents directly into
76 * {@link org.apache.logging.log4j.core.layout.ByteBufferDestination}s without creating intermediate temporary
77 * Objects.
78 * <p>
79 * {@code True} by default iff all loggers are asynchronous because system property
80 * {@code Log4jContextSelector} is set to {@code org.apache.logging.log4j.core.async.AsyncLoggerContextSelector}.
81 * Disable by setting system property "log4j2.enable.direct.encoders" to "false".
82 *
83 * @since 2.6
84 */
85 public static final boolean ENABLE_DIRECT_ENCODERS = PropertiesUtil.getProperties().getBooleanProperty(
86 "log4j2.enable.direct.encoders", true); // enable GC-free text encoding by default
87 // the alternative is to enable GC-free encoding only by default only when using all-async loggers:
88 //AsyncLoggerContextSelector.class.getName().equals(PropertiesUtil.getProperties().getStringProperty(LOG4J_CONTEXT_SELECTOR)));
89
90 /**
91 * Initial StringBuilder size used in RingBuffer LogEvents to store the contents of reusable Messages.
92 * <p>
93 * The default value is {@value}, users can override with system property "log4j.initialReusableMsgSize".
94 * </p>
95 * @since 2.6
96 */
97 public static final int INITIAL_REUSABLE_MESSAGE_SIZE = size("log4j.initialReusableMsgSize", 128);
98
99 /**
100 * Maximum size of the StringBuilders used in RingBuffer LogEvents to store the contents of reusable Messages.
101 * After a large message has been delivered to the appenders, the StringBuilder is trimmed to this size.
102 * <p>
103 * The default value is {@value}, which allows the StringBuilder to resize three times from its initial size.
104 * Users can override with system property "log4j.maxReusableMsgSize".
105 * </p>
106 * @since 2.6
107 */
108 public static final int MAX_REUSABLE_MESSAGE_SIZE = size("log4j.maxReusableMsgSize", (128 * 2 + 2) * 2 + 2);
109
110 /**
111 * Size of CharBuffers used by text encoders.
112 * <p>
113 * The default value is {@value}, users can override with system property "log4j.encoder.charBufferSize".
114 * </p>
115 * @since 2.6
116 */
117 public static final int ENCODER_CHAR_BUFFER_SIZE = size("log4j.encoder.charBufferSize", 2048);
118
119 /**
120 * Default size of ByteBuffers used to encode LogEvents without allocating temporary objects.
121 * <p>
122 * The default value is {@value}, users can override with system property "log4j.encoder.byteBufferSize".
123 * </p>
124 * @see org.apache.logging.log4j.core.layout.ByteBufferDestination
125 * @since 2.6
126 */
127 public static final int ENCODER_BYTE_BUFFER_SIZE = size("log4j.encoder.byteBufferSize", 8 * 1024);
128
129
130 private static int size(final String property, final int defaultValue) {
131 return PropertiesUtil.getProperties().getIntegerProperty(property, defaultValue);
132 }
133
134 /**
135 * Prevent class instantiation.
136 */
137 private Constants() {
138 }
139 }