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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       * LOG4J2-2109 if {@code true}, MessagePatternConverter will always operate as though
59       * <pre>%m{nolookups}</pre> is configured.
60       *
61       * @since 2.10
62       * @deprecated Since 2.12.2
63       */
64      @Deprecated
65      public static final boolean FORMAT_MESSAGES_PATTERN_DISABLE_LOOKUPS = PropertiesUtil.getProperties().getBooleanProperty(
66              "log4j2.formatMsgNoLookups", false);
67  
68      /**
69       * {@code true} if we think we are running in a web container, based on the boolean value of system property
70       * "log4j2.is.webapp", or (if this system property is not set) whether the  {@code javax.servlet.Servlet} class
71       * is present in the classpath.
72       */
73      public static final boolean IS_WEB_APP = org.apache.logging.log4j.util.Constants.IS_WEB_APP;
74  
75      /**
76       * Kill switch for object pooling in ThreadLocals that enables much of the LOG4J2-1270 no-GC behaviour.
77       * <p>
78       * {@code True} for non-{@link #IS_WEB_APP web apps}, disable by setting system property
79       * "log4j2.enable.threadlocals" to "false".
80       *
81       * @since 2.6
82       */
83      public static final boolean ENABLE_THREADLOCALS = org.apache.logging.log4j.util.Constants.ENABLE_THREADLOCALS;
84  
85      /**
86       * Kill switch for garbage-free Layout behaviour that encodes LogEvents directly into
87       * {@link org.apache.logging.log4j.core.layout.ByteBufferDestination}s without creating intermediate temporary
88       * Objects.
89       * <p>
90       * {@code True} by default iff all loggers are asynchronous because system property
91       * {@code Log4jContextSelector} is set to {@code org.apache.logging.log4j.core.async.AsyncLoggerContextSelector}.
92       * Disable by setting system property "log4j2.enable.direct.encoders" to "false".
93       *
94       * @since 2.6
95       */
96      public static final boolean ENABLE_DIRECT_ENCODERS = PropertiesUtil.getProperties().getBooleanProperty(
97              "log4j2.enable.direct.encoders", true); // enable GC-free text encoding by default
98              // the alternative is to enable GC-free encoding only by default only when using all-async loggers:
99              //AsyncLoggerContextSelector.class.getName().equals(PropertiesUtil.getProperties().getStringProperty(LOG4J_CONTEXT_SELECTOR)));
100 
101     /**
102      * Initial StringBuilder size used in RingBuffer LogEvents to store the contents of reusable Messages.
103      * <p>
104      * The default value is {@value}, users can override with system property "log4j.initialReusableMsgSize".
105      * </p>
106      * @since 2.6
107      */
108     public static final int INITIAL_REUSABLE_MESSAGE_SIZE = size("log4j.initialReusableMsgSize", 128);
109 
110     /**
111      * Maximum size of the StringBuilders used in RingBuffer LogEvents to store the contents of reusable Messages.
112      * After a large message has been delivered to the appenders, the StringBuilder is trimmed to this size.
113      * <p>
114      * The default value is {@value}, which allows the StringBuilder to resize three times from its initial size.
115      * Users can override with system property "log4j.maxReusableMsgSize".
116      * </p>
117      * @since 2.6
118      */
119     public static final int MAX_REUSABLE_MESSAGE_SIZE = size("log4j.maxReusableMsgSize", (128 * 2 + 2) * 2 + 2);
120 
121     /**
122      * Size of CharBuffers used by text encoders.
123      * <p>
124      * The default value is {@value}, users can override with system property "log4j.encoder.charBufferSize".
125      * </p>
126      * @since 2.6
127      */
128     public static final int ENCODER_CHAR_BUFFER_SIZE = size("log4j.encoder.charBufferSize", 2048);
129 
130     /**
131      * Default size of ByteBuffers used to encode LogEvents without allocating temporary objects.
132      * <p>
133      * The default value is {@value}, users can override with system property "log4j.encoder.byteBufferSize".
134      * </p>
135      * @see org.apache.logging.log4j.core.layout.ByteBufferDestination
136      * @since 2.6
137      */
138     public static final int ENCODER_BYTE_BUFFER_SIZE = size("log4j.encoder.byteBufferSize", 8 * 1024);
139 
140 
141     private static int size(final String property, final int defaultValue) {
142         return PropertiesUtil.getProperties().getIntegerProperty(property, defaultValue);
143     }
144 
145     /**
146      * Prevent class instantiation.
147      */
148     private Constants() {
149     }
150 }