1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.bcel.util;
20
21 import java.lang.ref.SoftReference;
22 import java.util.HashMap;
23 import java.util.Map;
24
25 import org.apache.bcel.classfile.JavaClass;
26
27 /**
28 * This repository is used in situations where a Class is created outside the realm of a ClassLoader. Classes are loaded
29 * from the file systems using the paths specified in the given class path. By default, this is the value returned by
30 * ClassPath.getClassPath(). This repository holds onto classes with SoftReferences, and will reload as needed, in cases
31 * where memory sizes are important.
32 *
33 * @see org.apache.bcel.Repository
34 */
35 public class MemorySensitiveClassPathRepository extends AbstractClassPathRepository {
36
37 private final Map<String, SoftReference<JavaClass>> loadedClasses = new HashMap<>(); // CLASSNAME X JAVACLASS
38
39 /**
40 * Constructs a new MemorySensitiveClassPathRepository.
41 *
42 * @param path The class path.
43 */
44 public MemorySensitiveClassPathRepository(final ClassPath path) {
45 super(path);
46 }
47
48 /**
49 * Clear all entries from cache.
50 */
51 @Override
52 public void clear() {
53 loadedClasses.clear();
54 }
55
56 /**
57 * Find an already defined (cached) JavaClass object by name.
58 */
59 @Override
60 public JavaClass findClass(final String className) {
61 final SoftReference<JavaClass> ref = loadedClasses.get(className);
62 return ref == null ? null : ref.get();
63 }
64
65 /**
66 * Remove class from repository
67 */
68 @Override
69 public void removeClass(final JavaClass clazz) {
70 loadedClasses.remove(clazz.getClassName());
71 }
72
73 /**
74 * Store a new JavaClass instance into this Repository.
75 */
76 @Override
77 public void storeClass(final JavaClass clazz) {
78 // Not calling super.storeClass because this subclass maintains the mapping.
79 loadedClasses.put(clazz.getClassName(), new SoftReference<>(clazz));
80 clazz.setRepository(this);
81 }
82 }