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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.common.IoBuffer;
30 import org.apache.mina.common.IoEvent;
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46 public class DefaultIoEventSizeEstimator implements IoEventSizeEstimator {
47
48 private final ConcurrentMap<Class<?>, Integer> class2size = new ConcurrentHashMap<Class<?>, Integer>();
49
50 public DefaultIoEventSizeEstimator() {
51 class2size.put(boolean.class, 4);
52 class2size.put(byte.class, 1);
53 class2size.put(char.class, 2);
54 class2size.put(int.class, 4);
55 class2size.put(short.class, 2);
56 class2size.put(long.class, 8);
57 class2size.put(float.class, 4);
58 class2size.put(double.class, 8);
59 class2size.put(void.class, 0);
60 }
61
62 public int estimateSize(IoEvent event) {
63 return estimateSize((Object) event) + estimateSize(event.getParameter());
64 }
65
66 public int estimateSize(Object message) {
67 if (message == null) {
68 return 8;
69 }
70
71 int answer = 8 + estimateSize(message.getClass(), null);
72
73 if (message instanceof IoBuffer) {
74 answer += ((IoBuffer) message).remaining();
75 } else if (message instanceof CharSequence) {
76 answer += ((CharSequence) message).length() << 1;
77 } else if (message instanceof Iterable) {
78 for (Object m: (Iterable<?>) message) {
79 answer += estimateSize(m);
80 }
81 }
82
83 return align(answer);
84 }
85
86 private int estimateSize(Class<?> clazz, Set<Class<?>> visitedClasses) {
87 Integer objectSize = class2size.get(clazz);
88 if (objectSize != null) {
89 return objectSize;
90 }
91
92 if (visitedClasses != null) {
93 if (visitedClasses.contains(clazz)) {
94 return 0;
95 }
96 } else {
97 visitedClasses = new HashSet<Class<?>>();
98 }
99
100 visitedClasses.add(clazz);
101
102 int answer = 8;
103 for (Class<?> c = clazz; c != null; c = c.getSuperclass()) {
104 Field[] fields = c.getDeclaredFields();
105 for (Field f: fields) {
106 if ((f.getModifiers() & Modifier.STATIC) != 0) {
107
108 continue;
109 }
110
111 answer += estimateSize(f.getType(), visitedClasses);
112 }
113 }
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115 visitedClasses.remove(clazz);
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117
118 answer = align(answer);
119
120
121 class2size.putIfAbsent(clazz, answer);
122 return answer;
123 }
124
125 private static int align(int size) {
126 if (size % 8 != 0) {
127 size /= 8;
128 size ++;
129 size *= 8;
130 }
131 return size;
132 }
133 }