1 /***
2 * Copyright 2003-2010 Terracotta, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package net.sf.ehcache.pool.sizeof;
18
19 import java.lang.reflect.Array;
20 import java.lang.reflect.Field;
21 import java.lang.reflect.Modifier;
22 import java.util.Stack;
23
24 import net.sf.ehcache.pool.sizeof.filter.PassThroughFilter;
25 import net.sf.ehcache.pool.sizeof.filter.SizeOfFilter;
26
27 import static net.sf.ehcache.pool.sizeof.JvmInformation.MINIMUM_OBJECT_SIZE;
28 import static net.sf.ehcache.pool.sizeof.JvmInformation.OBJECT_ALIGNMENT;
29 import static net.sf.ehcache.pool.sizeof.JvmInformation.POINTER_SIZE;
30
31 /***
32 * SizeOf that uses reflection to measure on heap size of object graphs
33 *
34 * @author Alex Snaps
35 * @author Chris Dennis
36 */
37 public class ReflectionSizeOf extends SizeOf {
38
39 /***
40 * Builds a new SizeOf that will not filter fields and will cache reflected fields
41 * @see #ReflectionSizeOf(net.sf.ehcache.pool.sizeof.filter.SizeOfFilter, boolean)
42 */
43 public ReflectionSizeOf() {
44 this(new PassThroughFilter());
45 }
46
47 /***
48 * Builds a new SizeOf that will filter fields and will cache reflected fields
49 * @param fieldFilter The filter to apply
50 * @see #ReflectionSizeOf(net.sf.ehcache.pool.sizeof.filter.SizeOfFilter, boolean)
51 * @see SizeOfFilter
52 */
53 public ReflectionSizeOf(SizeOfFilter fieldFilter) {
54 this(fieldFilter, true);
55 }
56
57 /***
58 * Builds a new SizeOf that will filter fields
59 * @param fieldFilter The filter to apply
60 * @param caching Whether to cache reflected fields
61 * @see SizeOfFilter
62 */
63 public ReflectionSizeOf(SizeOfFilter fieldFilter, boolean caching) {
64 super(fieldFilter, caching);
65 }
66
67 /***
68 * {@inheritDoc}
69 */
70 @Override
71 protected long measureSizeOf(Object obj) {
72 if (obj == null) {
73 return 0;
74 }
75
76 Class<?> aClass = obj.getClass();
77 if (aClass.isArray()) {
78 return guessArraySize(obj);
79 } else {
80 long size = PrimitiveType.CLASS.getSize();
81
82 Stack<Class<?>> classStack = new Stack<Class<?>>();
83 for (Class<?> klazz = aClass; klazz != null; klazz = klazz.getSuperclass()) {
84 classStack.push(klazz);
85 }
86
87 while (!classStack.isEmpty()) {
88 Class<?> klazz = classStack.pop();
89
90
91 int oops = 0;
92 int doubles = 0;
93 int words = 0;
94 int shorts = 0;
95 int bytes = 0;
96 for (Field f : klazz.getDeclaredFields()) {
97 if (Modifier.isStatic(f.getModifiers())) {
98 continue;
99 }
100 if (f.getType().isPrimitive()) {
101 switch (PrimitiveType.forType(f.getType())) {
102 case BOOLEAN:
103 case BYTE:
104 bytes++;
105 break;
106 case SHORT:
107 case CHAR:
108 shorts++;
109 break;
110 case INT:
111 case FLOAT:
112 words++;
113 break;
114 case DOUBLE:
115 case LONG:
116 doubles++;
117 break;
118 default:
119 throw new AssertionError();
120 }
121 } else {
122 oops++;
123 }
124 }
125 if (doubles > 0 && (size % PrimitiveType.LONG.getSize()) != 0) {
126 long length = PrimitiveType.LONG.getSize() - (size % PrimitiveType.LONG.getSize());
127 size += PrimitiveType.LONG.getSize() - (size % PrimitiveType.LONG.getSize());
128
129 while (length >= PrimitiveType.INT.getSize() && words > 0) {
130 length -= PrimitiveType.INT.getSize();
131 words--;
132 }
133 while (length >= PrimitiveType.SHORT.getSize() && shorts > 0) {
134 length -= PrimitiveType.SHORT.getSize();
135 shorts--;
136 }
137 while (length >= PrimitiveType.BYTE.getSize() && bytes > 0) {
138 length -= PrimitiveType.BYTE.getSize();
139 bytes--;
140 }
141 while (length >= PrimitiveType.getReferenceSize() && oops > 0) {
142 length -= PrimitiveType.getReferenceSize();
143 oops--;
144 }
145 }
146 size += PrimitiveType.DOUBLE.getSize() * doubles;
147 size += PrimitiveType.INT.getSize() * words;
148 size += PrimitiveType.SHORT.getSize() * shorts;
149 size += PrimitiveType.BYTE.getSize() * bytes;
150
151 if (oops > 0) {
152 if ((size % PrimitiveType.getReferenceSize()) != 0) {
153 size += PrimitiveType.getReferenceSize() - (size % PrimitiveType.getReferenceSize());
154 }
155 size += oops * PrimitiveType.getReferenceSize();
156 }
157
158 if ((doubles + words + shorts + bytes + oops) > 0 && (size % POINTER_SIZE) != 0) {
159 size += JvmInformation.POINTER_SIZE - (size % POINTER_SIZE);
160 }
161 }
162 if ((size % OBJECT_ALIGNMENT) != 0) {
163 size += OBJECT_ALIGNMENT - (size % OBJECT_ALIGNMENT);
164 }
165 return Math.max(size, MINIMUM_OBJECT_SIZE);
166 }
167 }
168
169 private long guessArraySize(Object obj) {
170 long size = PrimitiveType.getArraySize();
171 int length = Array.getLength(obj);
172 if (length != 0) {
173 Class<?> arrayElementClazz = obj.getClass().getComponentType();
174 if (arrayElementClazz.isPrimitive()) {
175 size += length * PrimitiveType.forType(arrayElementClazz).getSize();
176 } else {
177 size += length * PrimitiveType.getReferenceSize();
178 }
179 }
180 if ((size % OBJECT_ALIGNMENT) != 0) {
181 size += OBJECT_ALIGNMENT - (size % OBJECT_ALIGNMENT);
182 }
183 return Math.max(size, MINIMUM_OBJECT_SIZE);
184 }
185 }