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20 package org.apache.mina.filter.executor;
21
22 import java.lang.reflect.Field;
23 import java.lang.reflect.Modifier;
24 import java.util.HashSet;
25 import java.util.Set;
26 import java.util.concurrent.ConcurrentHashMap;
27 import java.util.concurrent.ConcurrentMap;
28
29 import org.apache.mina.core.buffer.IoBuffer;
30 import org.apache.mina.core.session.IoEvent;
31 import org.apache.mina.core.write.WriteRequest;
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47 public class DefaultIoEventSizeEstimator implements IoEventSizeEstimator {
48
49 private final ConcurrentMap<Class<?>, Integer> class2size = new ConcurrentHashMap<Class<?>, Integer>();
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54
55 public DefaultIoEventSizeEstimator() {
56 class2size.put(boolean.class, 4);
57 class2size.put(byte.class, 1);
58 class2size.put(char.class, 2);
59 class2size.put(int.class, 4);
60 class2size.put(short.class, 2);
61 class2size.put(long.class, 8);
62 class2size.put(float.class, 4);
63 class2size.put(double.class, 8);
64 class2size.put(void.class, 0);
65 }
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67
68
69
70 public int estimateSize(IoEvent event) {
71 return estimateSize((Object) event) + estimateSize(event.getParameter());
72 }
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78
79 public int estimateSize(Object message) {
80 if (message == null) {
81 return 8;
82 }
83
84 int answer = 8 + estimateSize(message.getClass(), null);
85
86 if (message instanceof IoBuffer) {
87 answer += ((IoBuffer) message).remaining();
88 } else if (message instanceof WriteRequest) {
89 answer += estimateSize(((WriteRequest) message).getMessage());
90 } else if (message instanceof CharSequence) {
91 answer += ((CharSequence) message).length() << 1;
92 } else if (message instanceof Iterable) {
93 for (Object m: (Iterable<?>) message) {
94 answer += estimateSize(m);
95 }
96 }
97
98 return align(answer);
99 }
100
101 private int estimateSize(Class<?> clazz, Set<Class<?>> visitedClasses) {
102 Integer objectSize = class2size.get(clazz);
103 if (objectSize != null) {
104 return objectSize;
105 }
106
107 if (visitedClasses != null) {
108 if (visitedClasses.contains(clazz)) {
109 return 0;
110 }
111 } else {
112 visitedClasses = new HashSet<Class<?>>();
113 }
114
115 visitedClasses.add(clazz);
116
117 int answer = 8;
118 for (Class<?> c = clazz; c != null; c = c.getSuperclass()) {
119 Field[] fields = c.getDeclaredFields();
120 for (Field f: fields) {
121 if ((f.getModifiers() & Modifier.STATIC) != 0) {
122
123 continue;
124 }
125
126 answer += estimateSize(f.getType(), visitedClasses);
127 }
128 }
129
130 visitedClasses.remove(clazz);
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133 answer = align(answer);
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136 class2size.putIfAbsent(clazz, answer);
137 return answer;
138 }
139
140 private static int align(int size) {
141 if (size % 8 != 0) {
142 size /= 8;
143 size ++;
144 size *= 8;
145 }
146 return size;
147 }
148 }