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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.config.plugins;
18  
19  import org.apache.logging.log4j.Logger;
20  import org.apache.logging.log4j.core.helpers.Loader;
21  import org.apache.logging.log4j.status.StatusLogger;
22  
23  import java.io.BufferedInputStream;
24  import java.io.BufferedOutputStream;
25  import java.io.DataInputStream;
26  import java.io.DataOutputStream;
27  import java.io.File;
28  import java.io.FileOutputStream;
29  import java.io.IOException;
30  import java.io.InputStream;
31  import java.net.URL;
32  import java.text.DecimalFormat;
33  import java.util.Enumeration;
34  import java.util.HashMap;
35  import java.util.Map;
36  import java.util.concurrent.ConcurrentHashMap;
37  import java.util.concurrent.ConcurrentMap;
38  import java.util.concurrent.CopyOnWriteArrayList;
39  
40  /**
41   * Component that loads and manages all the plugins.
42   */
43  public class PluginManager {
44  
45      private static final long NANOS_PER_SECOND = 1000000000L;
46  
47      private static ConcurrentMap<String, ConcurrentMap<String, PluginType>> pluginTypeMap =
48          new ConcurrentHashMap<String, ConcurrentMap<String, PluginType>>();
49  
50      private static final CopyOnWriteArrayList<String> PACKAGES = new CopyOnWriteArrayList<String>();
51      private static final String PATH = "org/apache/logging/log4j/core/config/plugins/";
52      private static final String FILENAME = "Log4j2Plugins.dat";
53      private static final String LOG4J_PACKAGES = "org.apache.logging.log4j.core";
54  
55      private static final Logger LOGGER = StatusLogger.getLogger();
56  
57      private static String rootDir;
58  
59      private Map<String, PluginType> plugins = new HashMap<String, PluginType>();
60      private final String type;
61      private final Class<?> clazz;
62  
63      /**
64       * Constructor that takes only a type name.
65       * @param type The type name.
66       */
67      public PluginManager(final String type) {
68          this.type = type;
69          this.clazz = null;
70      }
71  
72      /**
73       * Constructor that takes a type name and a Class.
74       * @param type The type that must be matched.
75       * @param clazz The Class each match must be an instance of.
76       */
77      public PluginManager(final String type, final Class<?> clazz) {
78          this.type = type;
79          this.clazz = clazz;
80      }
81  
82      public static void main(final String[] args) throws Exception {
83          if (args == null || args.length < 1) {
84              System.err.println("A target directory must be specified");
85              System.exit(-1);
86          }
87          rootDir = args[0].endsWith("/") || args[0].endsWith("\\") ? args[0] : args[0] + "/";
88  
89          final PluginManager manager = new PluginManager("Core");
90          final String packages = args.length == 2 ? args[1] : null;
91  
92          manager.collectPlugins(false, packages);
93          encode(pluginTypeMap);
94      }
95  
96      /**
97       * Adds a package name to be scanned for plugins. Must be invoked prior to plugins being collected.
98       * @param p The package name.
99       */
100     public static void addPackage(final String p) {
101         PACKAGES.addIfAbsent(p);
102     }
103 
104     /**
105      * Returns the type of a specified plugin.
106      * @param name The name of the plugin.
107      * @return The plugin's type.
108      */
109     public PluginType getPluginType(final String name) {
110         return plugins.get(name.toLowerCase());
111     }
112 
113     /**
114      * Returns all the matching plugins.
115      * @return A Map containing the name of the plugin and its type.
116      */
117     public Map<String, PluginType> getPlugins() {
118         return plugins;
119     }
120 
121     /**
122      * Locates all the plugins.
123      */
124     public void collectPlugins() {
125         collectPlugins(true, null);
126     }
127 
128     /**
129      * Collects plugins, optionally obtaining them from a preload map.
130      * @param preLoad if true, plugins will be obtained from the preload map.
131      * @param pkgs A comma separated list of package names to scan for plugins. If
132      * null the default Log4j package name will be used.
133      */
134     public void collectPlugins(boolean preLoad, final String pkgs) {
135         if (pluginTypeMap.containsKey(type)) {
136             plugins = pluginTypeMap.get(type);
137             preLoad = false;
138         }
139         final long start = System.nanoTime();
140         final ResolverUtil resolver = new ResolverUtil();
141         final ClassLoader loader = Loader.getClassLoader();
142         if (loader != null) {
143             resolver.setClassLoader(loader);
144         }
145         if (preLoad) {
146             final ConcurrentMap<String, ConcurrentMap<String, PluginType>> map = decode(loader);
147             if (map != null) {
148                 pluginTypeMap = map;
149                 plugins = map.get(type);
150             } else {
151                 LOGGER.warn("Plugin preloads not available");
152             }
153         }
154         if (plugins.size() == 0) {
155             if (pkgs == null) {
156                 PACKAGES.add(LOG4J_PACKAGES);
157             } else {
158                 final String[] names = pkgs.split(",");
159                 for (final String name : names) {
160                     PACKAGES.add(name);
161                 }
162             }
163         }
164         final ResolverUtil.Test test = new PluginTest(clazz);
165         for (final String pkg : PACKAGES) {
166             resolver.findInPackage(test, pkg);
167         }
168         for (final Class<?> clazz : resolver.getClasses()) {
169             final Plugin plugin = clazz.getAnnotation(Plugin.class);
170             final String pluginType = plugin.type();
171             if (!pluginTypeMap.containsKey(pluginType)) {
172                 pluginTypeMap.putIfAbsent(pluginType, new ConcurrentHashMap<String, PluginType>());
173             }
174             final Map<String, PluginType> map = pluginTypeMap.get(pluginType);
175             final String type = plugin.elementType().equals(Plugin.EMPTY) ? plugin.name() : plugin.elementType();
176             map.put(plugin.name().toLowerCase(), new PluginType(clazz, type, plugin.printObject(),
177                 plugin.deferChildren()));
178         }
179         long elapsed = System.nanoTime() - start;
180         plugins = pluginTypeMap.get(type);
181         final StringBuilder sb = new StringBuilder("Generated plugins");
182         sb.append(" in ");
183         DecimalFormat numFormat = new DecimalFormat("#0");
184         final long seconds = elapsed / NANOS_PER_SECOND;
185         elapsed %= NANOS_PER_SECOND;
186         sb.append(numFormat.format(seconds)).append('.');
187         numFormat = new DecimalFormat("000000000");
188         sb.append(numFormat.format(elapsed)).append(" seconds");
189         LOGGER.debug(sb.toString());
190     }
191 
192     private static ConcurrentMap<String, ConcurrentMap<String, PluginType>> decode(final ClassLoader loader) {
193         Enumeration<URL> resources;
194         try {
195             resources = loader.getResources(PATH + FILENAME);
196         } catch (final IOException ioe) {
197             LOGGER.warn("Unable to preload plugins", ioe);
198             return null;
199         }
200         final ConcurrentMap<String, ConcurrentMap<String, PluginType>> map =
201             new ConcurrentHashMap<String, ConcurrentMap<String, PluginType>>();
202         while (resources.hasMoreElements()) {
203             try {
204                 final URL url = resources.nextElement();
205                 LOGGER.debug("Found Plugin Map at {}", url.toExternalForm());
206                 final InputStream is = url.openStream();
207                 final BufferedInputStream bis = new BufferedInputStream(is);
208                 final DataInputStream dis = new DataInputStream(bis);
209                 final int count = dis.readInt();
210                 for (int j = 0; j < count; ++j) {
211                     final String type = dis.readUTF();
212                     final int entries = dis.readInt();
213                     ConcurrentMap<String, PluginType> types = map.get(type);
214                     if (types == null) {
215                         types = new ConcurrentHashMap<String, PluginType>(count);
216                     }
217                     for (int i = 0; i < entries; ++i) {
218                         final String key = dis.readUTF();
219                         final String className = dis.readUTF();
220                         final String name = dis.readUTF();
221                         final boolean printable = dis.readBoolean();
222                         final boolean defer = dis.readBoolean();
223                         final Class<?> clazz = Class.forName(className);
224                         types.put(key, new PluginType(clazz, name, printable, defer));
225                     }
226                     map.putIfAbsent(type, types);
227                 }
228                 dis.close();
229             } catch (final Exception ex) {
230                 LOGGER.warn("Unable to preload plugins", ex);
231                 return null;
232             }
233         }
234         return map.size() == 0 ? null : map;
235     }
236 
237     private static void encode(final ConcurrentMap<String, ConcurrentMap<String, PluginType>> map) {
238         final String fileName = rootDir + PATH + FILENAME;
239         try {
240             final File file = new File(rootDir + PATH);
241             file.mkdirs();
242             final FileOutputStream fos = new FileOutputStream(fileName);
243             final BufferedOutputStream bos = new BufferedOutputStream(fos);
244             final DataOutputStream dos = new DataOutputStream(bos);
245             dos.writeInt(map.size());
246             for (final Map.Entry<String, ConcurrentMap<String, PluginType>> outer : map.entrySet()) {
247                 dos.writeUTF(outer.getKey());
248                 dos.writeInt(outer.getValue().size());
249                 for (final Map.Entry<String, PluginType> entry : outer.getValue().entrySet()) {
250                     dos.writeUTF(entry.getKey());
251                     final PluginType pt = entry.getValue();
252                     dos.writeUTF(pt.getPluginClass().getName());
253                     dos.writeUTF(pt.getElementName());
254                     dos.writeBoolean(pt.isObjectPrintable());
255                     dos.writeBoolean(pt.isDeferChildren());
256                 }
257             }
258             dos.close();
259         } catch (final Exception ex) {
260             ex.printStackTrace();
261         }
262     }
263 
264     /**
265      * A Test that checks to see if each class is annotated with a specific annotation. If it
266      * is, then the test returns true, otherwise false.
267      */
268     public static class PluginTest extends ResolverUtil.ClassTest {
269         private final Class<?> isA;
270 
271         /**
272          * Constructs an AnnotatedWith test for the specified annotation type.
273          * @param isA The class to compare against.
274          */
275         public PluginTest(final Class<?> isA) {
276             this.isA = isA;
277         }
278 
279         /**
280          * Returns true if the type is annotated with the class provided to the constructor.
281          * @param type The type to check for.
282          * @return true if the Class is of the specified type.
283          */
284         public boolean matches(final Class<?> type) {
285             return type != null && type.isAnnotationPresent(Plugin.class) &&
286                 (isA == null || isA.isAssignableFrom(type));
287         }
288 
289         @Override
290         public String toString() {
291             final StringBuilder msg = new StringBuilder("annotated with @" + Plugin.class.getSimpleName());
292             if (isA != null) {
293                 msg.append(" is assignable to " + isA.getSimpleName());
294             }
295             return msg.toString();
296         }
297     }
298 
299 }