001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.logging.log4j.core.config.plugins.processor;
019
020 import org.apache.logging.log4j.core.util.Closer;
021
022 import java.io.BufferedInputStream;
023 import java.io.BufferedOutputStream;
024 import java.io.DataInputStream;
025 import java.io.DataOutputStream;
026 import java.io.IOException;
027 import java.io.OutputStream;
028 import java.net.URL;
029 import java.util.Enumeration;
030 import java.util.LinkedHashMap;
031 import java.util.Map;
032
033 /**
034 *
035 */
036 public class PluginCache {
037 private final Map<String, Map<String, PluginEntry>> categories =
038 new LinkedHashMap<String, Map<String, PluginEntry>>();
039
040 /**
041 * Returns all categories of plugins in this cache.
042 *
043 * @return all categories of plugins in this cache.
044 * @since 2.1
045 */
046 public Map<String, Map<String, PluginEntry>> getAllCategories() {
047 return categories;
048 }
049
050 /**
051 * Gets or creates a category of plugins.
052 *
053 * @param category name of category to look up.
054 * @return plugin mapping of names to plugin entries.
055 */
056 public Map<String, PluginEntry> getCategory(final String category) {
057 final String key = category.toLowerCase();
058 if (!categories.containsKey(key)) {
059 categories.put(key, new LinkedHashMap<String, PluginEntry>());
060 }
061 return categories.get(key);
062 }
063
064 /**
065 * Stores the plugin cache to a given OutputStream.
066 *
067 * @param os destination to save cache to.
068 * @throws IOException
069 */
070 // NOTE: if this file format is to be changed, the filename should change and this format should still be readable
071 public void writeCache(final OutputStream os) throws IOException {
072 final DataOutputStream out = new DataOutputStream(new BufferedOutputStream(os));
073 try {
074 // See PluginManager.readFromCacheFiles for the corresponding decoder. Format may not be changed
075 // without breaking existing Log4j2Plugins.dat files.
076 out.writeInt(categories.size());
077 for (final Map.Entry<String, Map<String, PluginEntry>> category : categories.entrySet()) {
078 out.writeUTF(category.getKey());
079 final Map<String, PluginEntry> m = category.getValue();
080 out.writeInt(m.size());
081 for (final Map.Entry<String, PluginEntry> entry : m.entrySet()) {
082 final PluginEntry plugin = entry.getValue();
083 out.writeUTF(plugin.getKey());
084 out.writeUTF(plugin.getClassName());
085 out.writeUTF(plugin.getName());
086 out.writeBoolean(plugin.isPrintable());
087 out.writeBoolean(plugin.isDefer());
088 }
089 }
090 } finally {
091 Closer.closeSilently(out);
092 }
093 }
094
095 /**
096 * Loads and merges all the Log4j plugin cache files specified. Usually, this is obtained via a ClassLoader.
097 *
098 * @param resources URLs to all the desired plugin cache files to load.
099 * @throws IOException
100 */
101 public void loadCacheFiles(final Enumeration<URL> resources) throws IOException {
102 categories.clear();
103 while (resources.hasMoreElements()) {
104 final URL url = resources.nextElement();
105 final DataInputStream in = new DataInputStream(new BufferedInputStream(url.openStream()));
106 try {
107 final int count = in.readInt();
108 for (int i = 0; i < count; i++) {
109 final String category = in.readUTF();
110 final Map<String, PluginEntry> m = getCategory(category);
111 final int entries = in.readInt();
112 for (int j = 0; j < entries; j++) {
113 final PluginEntry entry = new PluginEntry();
114 entry.setKey(in.readUTF());
115 entry.setClassName(in.readUTF());
116 entry.setName(in.readUTF());
117 entry.setPrintable(in.readBoolean());
118 entry.setDefer(in.readBoolean());
119 entry.setCategory(category);
120 if (!m.containsKey(entry.getKey())) {
121 m.put(entry.getKey(), entry);
122 }
123 }
124 }
125 } finally {
126 Closer.closeSilently(in);
127 }
128 }
129 }
130
131 /**
132 * Gets the number of plugin categories registered.
133 *
134 * @return number of plugin categories in cache.
135 */
136 public int size() {
137 return categories.size();
138 }
139 }