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.bcel.util;
18
19 import java.lang.ref.SoftReference;
20 import java.util.HashMap;
21 import java.util.Map;
22
23 import org.apache.bcel.classfile.JavaClass;
24
25 /**
26 * This repository is used in situations where a Class is created outside the realm of a ClassLoader. Classes are loaded
27 * from the file systems using the paths specified in the given class path. By default, this is the value returned by
28 * ClassPath.getClassPath(). This repository holds onto classes with SoftReferences, and will reload as needed, in cases
29 * where memory sizes are important.
30 *
31 * @see org.apache.bcel.Repository
32 */
33 public class MemorySensitiveClassPathRepository extends AbstractClassPathRepository {
34
35 private final Map<String, SoftReference<JavaClass>> loadedClasses = new HashMap<>(); // CLASSNAME X JAVACLASS
36
37 public MemorySensitiveClassPathRepository(final ClassPath path) {
38 super(path);
39 }
40
41 /**
42 * Clear all entries from cache.
43 */
44 @Override
45 public void clear() {
46 loadedClasses.clear();
47 }
48
49 /**
50 * Find an already defined (cached) JavaClass object by name.
51 */
52 @Override
53 public JavaClass findClass(final String className) {
54 final SoftReference<JavaClass> ref = loadedClasses.get(className);
55 return ref == null ? null : ref.get();
56 }
57
58 /**
59 * Remove class from repository
60 */
61 @Override
62 public void removeClass(final JavaClass clazz) {
63 loadedClasses.remove(clazz.getClassName());
64 }
65
66 /**
67 * Store a new JavaClass instance into this Repository.
68 */
69 @Override
70 public void storeClass(final JavaClass clazz) {
71 // Not calling super.storeClass because this subclass maintains the mapping.
72 loadedClasses.put(clazz.getClassName(), new SoftReference<>(clazz));
73 clazz.setRepository(this);
74 }
75 }