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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>();
50
51 public DefaultIoEventSizeEstimator() {
52 class2size.put(boolean.class, 4);
53 class2size.put(byte.class, 1);
54 class2size.put(char.class, 2);
55 class2size.put(int.class, 4);
56 class2size.put(short.class, 2);
57 class2size.put(long.class, 8);
58 class2size.put(float.class, 4);
59 class2size.put(double.class, 8);
60 class2size.put(void.class, 0);
61 }
62
63 public int estimateSize(IoEvent event) {
64 return estimateSize((Object) event) + estimateSize(event.getParameter());
65 }
66
67 public int estimateSize(Object message) {
68 if (message == null) {
69 return 8;
70 }
71
72 int answer = 8 + estimateSize(message.getClass(), null);
73
74 if (message instanceof IoBuffer) {
75 answer += ((IoBuffer) message).remaining();
76 } else if (message instanceof WriteRequest) {
77 answer += estimateSize(((WriteRequest) message).getMessage());
78 } else if (message instanceof CharSequence) {
79 answer += ((CharSequence) message).length() << 1;
80 } else if (message instanceof Iterable) {
81 for (Object m: (Iterable<?>) message) {
82 answer += estimateSize(m);
83 }
84 }
85
86 return align(answer);
87 }
88
89 private int estimateSize(Class<?> clazz, Set<Class<?>> visitedClasses) {
90 Integer objectSize = class2size.get(clazz);
91 if (objectSize != null) {
92 return objectSize;
93 }
94
95 if (visitedClasses != null) {
96 if (visitedClasses.contains(clazz)) {
97 return 0;
98 }
99 } else {
100 visitedClasses = new HashSet<Class<?>>();
101 }
102
103 visitedClasses.add(clazz);
104
105 int answer = 8;
106 for (Class<?> c = clazz; c != null; c = c.getSuperclass()) {
107 Field[] fields = c.getDeclaredFields();
108 for (Field f: fields) {
109 if ((f.getModifiers() & Modifier.STATIC) != 0) {
110
111 continue;
112 }
113
114 answer += estimateSize(f.getType(), visitedClasses);
115 }
116 }
117
118 visitedClasses.remove(clazz);
119
120
121 answer = align(answer);
122
123
124 class2size.putIfAbsent(clazz, answer);
125 return answer;
126 }
127
128 private static int align(int size) {
129 if (size % 8 != 0) {
130 size /= 8;
131 size ++;
132 size *= 8;
133 }
134 return size;
135 }
136 }