1 /*
2 * Copyright (c) 2004-2013 QOS.ch
3 * All rights reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be
14 * included in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 */
25 package org.slf4j.impl;
26
27 import org.slf4j.ILoggerFactory;
28 import org.slf4j.Logger;
29
30 import java.util.concurrent.ConcurrentHashMap;
31 import java.util.concurrent.ConcurrentMap;
32
33 /**
34 * AndroidLoggerFactory is an implementation of {@link ILoggerFactory} returning
35 * the appropriately named {@link AndroidLoggerFactory} instance.
36 *
37 * @author Andrey Korzhevskiy <a.korzhevskiy@gmail.com>
38 */
39 class AndroidLoggerFactory implements ILoggerFactory {
40 static final String ANONYMOUS_TAG = "null";
41 static final int TAG_MAX_LENGTH = 23;
42
43 private final ConcurrentMap<String, Logger> loggerMap = new ConcurrentHashMap<String, Logger>();
44
45 /**
46 * Return an appropriate {@link AndroidLoggerAdapter} instance by name.
47 */
48 public Logger getLogger(String name) {
49 String tag = loggerNameToTag(name);
50 Logger logger = loggerMap.get(tag);
51 if (logger == null) {
52 Logger newInstance = new AndroidLoggerAdapter(tag);
53 Logger oldInstance = loggerMap.putIfAbsent(tag, newInstance);
54 logger = oldInstance == null ? newInstance : oldInstance;
55 }
56 return logger;
57 }
58
59 /**
60 * Tag names cannot be longer than {@value #TAG_MAX_LENGTH} characters on Android platform.
61 *
62 * Returns the short logger tag (up to {@value #TAG_MAX_LENGTH} characters) for the given logger name.
63 * Traditionally loggers are named by fully-qualified Java classes; this
64 * method attempts to return a concise identifying part of such names.
65 *
66 * See also:
67 * android/system/core/include/cutils/property.h
68 * android/frameworks/base/core/jni/android_util_Log.cpp
69 * dalvik.system.DalvikLogging
70 *
71 */
72 static String loggerNameToTag(String loggerName) {
73 // Anonymous logger
74 if (loggerName == null) {
75 return ANONYMOUS_TAG;
76 }
77
78 int length = loggerName.length();
79 if (length <= TAG_MAX_LENGTH) {
80 return loggerName;
81 }
82
83 int tagLength = 0;
84 int lastTokenIndex = 0;
85 int lastPeriodIndex;
86 StringBuilder tagName = new StringBuilder(TAG_MAX_LENGTH + 3);
87 while ((lastPeriodIndex = loggerName.indexOf('.', lastTokenIndex)) != -1) {
88 tagName.append(loggerName.charAt(lastTokenIndex));
89 // token of one character appended as is otherwise truncate it to one character
90 int tokenLength = lastPeriodIndex - lastTokenIndex;
91 if (tokenLength > 1) {
92 tagName.append('*');
93 }
94 tagName.append('.');
95 lastTokenIndex = lastPeriodIndex + 1;
96
97 // check if name is already too long
98 tagLength = tagName.length();
99 if (tagLength > TAG_MAX_LENGTH) {
100 return getSimpleName(loggerName);
101 }
102 }
103
104 // Either we had no useful dot location at all
105 // or last token would exceed TAG_MAX_LENGTH
106 int tokenLength = length - lastTokenIndex;
107 if (tagLength == 0 || (tagLength + tokenLength) > TAG_MAX_LENGTH) {
108 return getSimpleName(loggerName);
109 }
110
111 // last token (usually class name) appended as is
112 tagName.append(loggerName, lastTokenIndex, length);
113 return tagName.toString();
114 }
115
116 private static String getSimpleName(String loggerName) {
117 // Take leading part and append '*' to indicate that it was truncated
118 int length = loggerName.length();
119 int lastPeriodIndex = loggerName.lastIndexOf('.');
120 return lastPeriodIndex != -1 && length - (lastPeriodIndex + 1) <= TAG_MAX_LENGTH
121 ? loggerName.substring(lastPeriodIndex + 1)
122 : '*' + loggerName.substring(length - TAG_MAX_LENGTH + 1);
123 }
124 }