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23 package org.jboss.netty.handler.execution;
24
25 import java.lang.reflect.Field;
26 import java.lang.reflect.Modifier;
27 import java.nio.ByteBuffer;
28 import java.util.HashSet;
29 import java.util.Set;
30 import java.util.concurrent.ConcurrentHashMap;
31 import java.util.concurrent.ConcurrentMap;
32
33 import org.jboss.netty.buffer.ChannelBuffer;
34 import org.jboss.netty.channel.MessageEvent;
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44
45 public class DefaultObjectSizeEstimator implements ObjectSizeEstimator {
46
47 private final ConcurrentMap<Class<?>, Integer> class2size =
48 new ConcurrentHashMap<Class<?>, Integer>();
49
50
51
52
53 public DefaultObjectSizeEstimator() {
54 class2size.put(boolean.class, 4);
55 class2size.put(byte.class, 1);
56 class2size.put(char.class, 2);
57 class2size.put(int.class, 4);
58 class2size.put(short.class, 2);
59 class2size.put(long.class, 8);
60 class2size.put(float.class, 4);
61 class2size.put(double.class, 8);
62 class2size.put(void.class, 0);
63 }
64
65 public int estimateSize(Object o) {
66 if (o == null) {
67 return 8;
68 }
69
70 int answer = 8 + estimateSize(o.getClass(), null);
71
72 if (o instanceof ChannelEventRunnable) {
73 answer += estimateSize(((ChannelEventRunnable) o).getEvent());
74 } else if (o instanceof MessageEvent) {
75 answer += estimateSize(((MessageEvent) o).getMessage());
76 } else if (o instanceof ChannelBuffer) {
77 answer += ((ChannelBuffer) o).capacity();
78 } else if (o instanceof byte[]) {
79 answer += ((byte[]) o).length;
80 } else if (o instanceof ByteBuffer) {
81 answer += ((ByteBuffer) o).remaining();
82 } else if (o instanceof CharSequence) {
83 answer += ((CharSequence) o).length() << 1;
84 } else if (o instanceof Iterable) {
85 for (Object m : (Iterable<?>) o) {
86 answer += estimateSize(m);
87 }
88 }
89
90 return align(answer);
91 }
92
93 private int estimateSize(Class<?> clazz, Set<Class<?>> visitedClasses) {
94 Integer objectSize = class2size.get(clazz);
95 if (objectSize != null) {
96 return objectSize;
97 }
98
99 if (visitedClasses != null) {
100 if (visitedClasses.contains(clazz)) {
101 return 0;
102 }
103 } else {
104 visitedClasses = new HashSet<Class<?>>();
105 }
106
107 visitedClasses.add(clazz);
108
109 int answer = 8;
110 for (Class<?> c = clazz; c != null; c = c.getSuperclass()) {
111 Field[] fields = c.getDeclaredFields();
112 for (Field f : fields) {
113 if ((f.getModifiers() & Modifier.STATIC) != 0) {
114
115 continue;
116 }
117
118 answer += estimateSize(f.getType(), visitedClasses);
119 }
120 }
121
122 visitedClasses.remove(clazz);
123
124
125 answer = align(answer);
126
127
128 class2size.putIfAbsent(clazz, answer);
129 return answer;
130 }
131
132 private static int align(int size) {
133 if (size % 8 != 0) {
134 size /= 8;
135 size ++;
136 size *= 8;
137 }
138 return size;
139 }
140 }